Orthognathic Surgery

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CHAPTER 5  Orthodontic Considerations in the Evaluation and Treatment of Dentofacial Deformities
leading to the belief that it is an important mediator of
tooth movement.
It is known that the osteoclasts attack the compressed
area of lamina dura to remove bone.184 The radiographic
appearance of a widened PDL (on the tension side) in the
presence of light prolonged orthodontic forces indicates
that tooth movement is soon to begin.66 On the compres­
sion side, osteoclasts are removing the lamina dura. On the
tension side, remodeling activity involves osteoblasts laying
down new bone. The course of events is different if the
prolonged force applied to the tooth is too great. If the force
transmitted to the periodontal ligament totally occludes the
blood vessels, thereby cutting off all blood supply to the
area, generalized necrosis occurs within the compressed
area. Although some avascular areas in the PDL will occur
even with light forces, if the predominant forces are “heavy,”
then the response is necrosis. Irreversible damage can then
occur, and this includes remodeling with the loss of crestal
bone, root resorption, and cortical plate dehiscence. The
histologic findings within the PDL—even with light forces
during the compression process—show the disappearance
of cells within the vessels. The histologic appearance is
descriptively said to be “hyalinized” because of its visual
resemblance to hyaline connective tissue. After this hyalin­
ization process begins, after several days of delay, the remod­
eling of bone that borders the sporadic necrotic areas of the
PDL will occur as osteoclasts (derived from adjacent undam­
aged areas) arrive and do their work. The process of bone
removal is called undermining resorption. This term is visu­
ally descriptive when it is viewed under the microscope,
because the attack by the osteoclasts is from the underside
of the lamina dura. After the hyalinization (i.e., the com­
pression of blood flow with isolated necrosis) and the
undermining resorption (i.e., the osteoclastic activity on the
underside of the lamina dura) have “softened” the lamina
dura, tooth movement is soon to occur. The chronology of
tooth movement with frontal resorption is different than
that of undermining resorption. With frontal resorption, a
steady attack on the outer surface of the lamina dura results
in smooth, continuous tooth movement. With undermin­
ing resorption, there will be a delay in the removal of the
bone adjacent to the tooth. When heavy force (i.e., pres­
sure) is again reinitiated, there will be a similar delay in
tooth movement until a second round of undermining
resorption can occur.171
The orthodontic movement of a tooth is clinically more
efficient when there are only minimal areas of PDL necrosis.
As a result, only limited levels of pain are experienced by
the individual undergoing treatment. Unfortunately, neither
aspect is completely avoidable. To date, a completely smooth
progression of tooth movement with consistent light force
over time has proven to be unattainable within the human
biologic system. One important compounding factor is that
the individual who is undergoing orthodontic tooth move­
ment must also continue with the everyday functions of
mastication, speech, swallowing, and breathing within a
affect cellular function, thereby causing the observed
changes in bone architecture. These two theories of bone
metabolism are also discussed and debated within the
orthopedic literature, and they are not mutually exclusive.
Many scientists and clinicians believe that both biologic
mechanisms play a role in the remodeling and repair of
bone. The pressure-tension theory represents the classic
theory of tooth movement. It proposes that chemical rather
than electric signals are the stimuli for the cellular differen­
tiation required to alter the tooth socket and ultimately to
move the teeth. In either case, when an alteration in blood
flow within the PDL occurs and is sustained through pres­
sure that is applied directly to a tooth, the tooth shifts
position within the PDL space, thereby compressing the
ligament on one side and stretching it on the other. Blood
flow is decreased where the PDL is compressed, although it
may be increased or maintained in areas in which the PDL
is under light tension. Interestingly, if the PDL is over­
stretched (i.e., if “heavy” tooth forces are applied), then the
blood flow may also be decreased on the tension side. It is
easy to understand how these alterations in blood flow can
create changes in the chemical environment. Oxygen levels
fall in the areas of compression, although they may even
increase on the tension side of the tooth socket. The changes
in oxygen content cause a series of biologic responses that
bring new cells into the area either through migration or
differentiation.
The Amount of Orthodontic Force Applied to
the Teeth
The heavier the sustained pressure, the greater the reduction
in blood flow where compression is occurring in the
PDL.25,166,174 When only light prolonged force is applied to a
tooth, the partially compressed PDL experiences dimin­
ished blood flow, and the interstitial fluids are expressed
(pushed out) from the PDL space as the tooth moves within
the socket.125 Animal experiments confirm that, within a
few hours, there will be increased levels of cyclic adenosine
monophosphate (cAMP).175 cAMP is known for its impor­
tance in the alteration of cell functions. Within 4 hours of
continued sustained low pressure, mesenchymal cell dif­
ferentiation occurs. From a clinical perspective, it is known
that, if orthodontic appliances are used for less than 4 to 6
hours per day, not enough sustained force will be applied,
and little or no tooth movement will occur.143,148
For the tooth to actually move further than just within
the socket itself, osteoclasts must arrive (i.e., migrate or
differentiate from mesenchymal cells) and then remove
bone from the area adjacent to the compressed part of the
PDL. Osteoblasts are required to form new bone on the
tension side. Prostaglandin E (a family of prostaglandins
that are often used pharmaceutically in medicine) has
been shown to increase its levels during this phase of ortho­
dontic tooth movement. It is known that prostaglandin E
stimulates both osteoclastic and osteoblastic activity, thereby

142
SECTION 1  Basic Principles and Concepts
Control of Force Duration and Decay in the
Orthodontic Movement of Teeth
A basic principle in the process of orthodontic tooth move­
ment is the application of sustained force. The force must be
present for a significant percentage of the time during the
whole process of tooth movement. Animal experiments
suggest that, only after force is maintained for approxi­
mately 4 to 6 hours, will levels of cAMP be measurably
increased in the PDL. Appropriate levels of cAMP are
thought to be necessary for the stimulation of cellular dif­
ferentiation. Human clinical experience suggests that a force
duration of at least 4 to 8 hours (per 24-hour cycle) is
required to effect tooth movement. The teeth can be moved
more rapidly if force is maintained for longer durations. In
fact, the application of continuous light force (24 hours per
day) would produce the most efficient tooth movement.
Through technical advances in materials and appliances, the
ability to apply continuous force and to control the dura­
tion of that force to each tooth has greatly improved. For
example, the nickel-titanium alloys and the self-ligating
brackets that are in use today have advanced the process of
the sustained duration of light force to achieve tooth move­
ment over time. Office visits can often be spaced every 6 to
10 weeks. Applied orthodontic forces are classified as either
continuous or interrupted (intermittent). In general, the
orthodontist would like to apply continuous force (or at least
some appreciable fraction of the original applied force) from
one patient visit to the next. Orthodontists also use inter­
mittent forces for specific purposes. The so-called activated
appliances (e.g., removable plates, headgear, elastics) may
be used intermittently.
Medication Effects on the Rate of Orthodontic
Tooth Movement
The bisphosphonates act as inhibitors of osteoclast-mediated
bone resorption, which by definition have an effect on bone
remodeling.5,102 There is evidence to suggest that tooth
movement in patients who are receiving parenteral bisphos­
phonate therapy may be retarded, with a subsequent risk
for osteonecrosis of the jaws.113
Bartzela and colleagues conducted a systematic review of
the literature regarding the effects of medications and
dietary supplements on the rate of experimental orthodon­
tic tooth movement.23 The results of their literature search
indicated the following:
• The therapeutic administration of eicosanoids results in
increased tooth movement.
• Nonsteroidal anti-inflammatory drugs decreased tooth
movement; however, non-nonsteroidal anti-inflammatory
analgesics (e.g., Paracetamol [acetaminophen]) had no
effect.
• Corticosteroid hormones, parathyroid hormone, and
thyroxin have all been shown to increase tooth
movement.
24-hour cycle. These functions also place forces on the
teeth, which may either conflict with or expedite the applied
orthodontic forces. Another factor is the relative ineffective­
ness of the appliances (i.e., the materials) used to apply
sustained appropriate levels of force. To review, in clinical
orthodontic practice, on one end of the spectrum, too much
sustained force is detrimental to the tissues; alternatively,
too little force will not produce the tooth movement that
is desired.25
Control of Orthodontic Tooth Movement
The basic principle of the ideal orthodontic movement of a
tooth includes the application of just enough force to stimu­
late required cellular activity without the complete occlusion
of the blood vessels within the PDL. For example, it is esti­
mated that as little as 30 g of force may be required to tip a
single rooted tooth. For controlled resorption and remodel­
ing to occur, force is first delivered to the tooth and then
to the PDL, which results in compression, tension, or both
at the appropriate locations of the lamina dura. Depending
on the desired three-dimensional repositioning of the tooth,
different amounts of pressure (i.e., the force per unit area)
are applied to different locations along the lamina dura.
The different basic forms of tooth movement include
tipping, rotation, and translation. Tipping results from a
single force applied at a distance to the center of resistance.
Although the center of resistance of a tooth is generally
located about halfway down the root, the center of rotation
for tipping movements is apical to that. Here, the crown
will move in one direction, and the apex will move in the
opposite direction. When the tooth tips in this fashion, the
PDL is compressed most strongly near the root apex on
the same side as the force being applied as well as at the
crest of the alveolar ridge on the opposite side. Progressively
less pressure is created as the center of rotation is approached,
where there is minimum pressure applied. During transla­
tion movement of the tooth, the PDL space is loaded uni­
formly from the alveolar crest to the apex on the side of
tooth compression. A pure translational force will allow for
the bodily movement of the tooth rather than tipping. The
forces that are required for the bodily movement (i.e., trans­
lation) of incisors up to multi-rooted teeth is in the range
of 70 to 120 g. This represents the maximum orthodontic
tooth movement force to be used in clinical practice. The
optimal force for the orthodontic rotation of a tooth around
its long axis (i.e., 35 to 60 g) is less than that required for
the bodily movement of a tooth. The optimal force required
for the orthodontic extrusion of a tooth is in the range of
35 to 60 g. The intrusion of teeth requires the carefully
controlled application of consistent very light forces that are
applied to the tooth in a specific way. It is difficult to apply
controlled intrusion forces to a tooth (i.e., 10 to 20 g)
without also applying tipping forces. Small implants (i.e.,
temporary anchorage devices [TADs]) can be used to help
this aspect of tooth movement and to provide greater
control, as described later in this chapter.

143
CHAPTER 5  Orthodontic Considerations in the Evaluation and Treatment of Dentofacial Deformities
(headgear), the face (a face mask), or implants into bone
(TADs).
Reciprocal Tooth Movement
When planning orthodontic therapy, the clinician must
consider not just the tooth movement that is desired but
any reciprocal effects that may occur throughout the dental
arches as well. Reciprocal effects must be controlled to
achieve the desired repositioning of all of the teeth and to
establish preferred occlusion. In a completely reciprocal
situation, Newton’s theory is easy to understand. When the
forces applied to similar teeth and to similar arch segments
are equal, there will be an equal force distribution in each
PDL with this same degree of movement. A classic clinical
case analysis that is frequently used to understand the
“reciprocal/nonreciprocal” concept is to consider the type
of tooth movement that occurs when an elastomeric chain
is placed across a first premolar extraction site in the maxilla.
This pits the central incisor, the lateral incisor, and the
canine in the anterior segment in opposition to the second
premolar and the first molar in the posterior segment. The
same total force would be felt by the three anterior teeth
and the two posterior teeth as the action of the chain is
equal in each segment. However, equal reciprocal move­
ment would require the same total PDL surface area over
which the force is distributed. Because the measured PDL
area for the two posterior teeth is larger than the three
anterior teeth, the movement will not be reciprocal. In this
typical, real-life clinical setting, the anterior teeth move
back into the bicuspid extraction sites more than the pos­
terior teeth migrate forward. If it is desired that the anterior
teeth move entirely into the extraction space, reinforced
anchorage will be required. This may be accomplished by
incorporating the second molar into the posterior unit. This
changes the root surface area ratios, which results in addi­
tional retraction of the anterior teeth. Other methods of
reinforcing posterior anchorage include the use of extra oral
force, such as headgear, TADs, and palatal support through
the use of Nance appliances or a transpalatal bar.148
Cortical Walls as Limiting Factors to
Orthodontic Tooth Movement
Cortical bone is more resistant to resorption; therefore,
tooth movement is slowed whenever the root to be moved
contacts it. This can be problematic, for example, when
there is a dense cortical layer of bone formed within the
alveolar process of a previously (long-ago) extracted tooth.
It can be more difficult to close an “old” extraction site,
because tooth movement is slowed to a minimum when the
root encounters cortical bone along the resorbing side of
the alveolar ridge.118,126 Tooth movement is also greatly
slowed and root resorption more likely when a tooth (or
tooth root) is forced against a cortical plate (e.g., a labial
plate, a lingual plate), such as may occur during attempts
to correct incisor inclination.
• Estrogens probably reduce tooth movement, although
no direct evidence is available.
• Vitamin D3 stimulates tooth movement, and dietary
calcium seems to reduce it.
The Role of Anchorage in the Orthodontic
Movement of Teeth
The term anchorage as it applies to orthodontics refers to
the nature and degree of resistance to displacement pro­
vided by an anatomic unit (e.g., molars and premolars,
temporary skeletal anchorage devices, hard palate) when it
is used for the purpose of effecting tooth movement.139
The principle of anchorage in the orthodontic movement
of teeth is an application of Sir Isaac Newton’s realization
that action and reaction are equal and opposite. Restated,
this means that, for every force that is directly applied, there
is an equal and opposite (reciprocal) force. Depending on
how the orthodontic force is applied to a tooth and given
the fact that each tooth has a different resistance value to
tooth movement (as a result of the nonuniform nature of
the teeth and the periodontium), the orthodontist may
choose to use certain teeth or groupings of teeth (e.g., ligat­
ing molars together as a unit) for “anchorage” when moving
other teeth into a more desirable position. Sources other
than teeth may also be used for anchorage, including TADs,
headgear, a facemask, the hard palate, or the lingual or
buccal alveolar supporting bone of the mandible.
Dental anchorage is most typically used to overcome resis­
tance to the orthodontic movement of teeth. To assess the
anchorage requirements of the desired tooth movement, the
clinician must first evaluate the part of each tooth that is
anchored into the alveolar bone. The overall anchorage
requirements primarily include the number of roots and the
shape, size, and length of each root of the teeth that require
movement. This is primarily the sum total of the surface
area of the root portions of the teeth that are enveloped by
alveolar bone and that are to be moved. A tooth (root) with
a large surface area (enveloped by alveolar bone) is more
resistant to displacement than one with a smaller surface
area. A multi-rooted tooth is more resistant to displacement
than a single-rooted tooth. A long-rooted tooth is more
difficult to move than a short-rooted tooth. A triangular-
shaped root offers greater resistance to movement than a
conical-shaped root. Other factors are also important,
including the following: (1) the relationship with the con­
tiguous teeth; (2) the ongoing forces of occlusion; (3) the
age of the patient and the soft-tissue forces on the teeth
(i.e., cheeks, tongue, and lips); and (4) the individual’s
unique tissue response. Thus, molars are generally good
teeth to use for anchorage, because they have deeper and
longer roots, they have a greater root surface area, and they
are less susceptible to tipping forces. As stated previously,
anchorage may also be increased by ligating multiple teeth
together, thereby summing their individual resistance.
Anchorage forces may also be provided by the hard palate,
the buccal cortical plate of the posterior mandible, the head

144
SECTION 1  Basic Principles and Concepts
The resorption of the tooth roots during orthodontic
treatment has been documented to occur in three distinct
forms: (1) moderate generalized resorption; (2) severe gen­
eralized resorption (see Figs. 5-5 and 5-6); and (3) severe
localized resorption. The shortening of the root length of
the maxillary incisors (i.e., severe localized resorption) is
seen more often than this condition appears to occur in the
other teeth (Fig. 5-7). Although some studies have shown
that measurable root resorption can be identified in 90% of
maxillary incisors and in more than half of all other teeth
during a typical fixed orthodontic appliance treatment,
the shortening is almost imperceptible, and it is clinically
insignificant for most. Nevertheless, occasionally the loss of
one third or one half or more of the root structure is
observed in patients who underwent what was considered
to be routine orthodontic treatment. When this does
occur, it is either severe generalized resorption or severe
localized resorption. Fortunately, severe root resorption of
all orthodontically treated teeth is not common. When
severe generalized resorption does occur, it is often seen
without any orthodontic or other forms of active dental
treatment, and it may be of an uncertain etiology. If there
is evidence of root resorption before orthodontic treatment,
the patient should be considered at high risk for further
resorption during orthodontic treatment. Radiographs
should be taken during treatment to watch for this
occurrence. If resorption becomes apparent, the patient is
informed, and the treatment plan altered. In contrast with
severe generalized resorption, severe localized resorption is
more frequently associated with specific forms of orthodon­
tic treatment. Risk factors are likely to include heavy con­
tinuous orthodontic forces being place on the teeth and a
prolonged duration of treatment. Localized resorption is
more frequently seen in the maxillary incisors, when the
root apices are forced against the facial cortical plate during
treatment. For example, in the clinician’s attempts to com­
pensate for a long face Class II skeletal pattern with an
anterior open bite, the maxillary incisor crowns may be
detorqued (resulting in a loss of proper buccolingual incli­
nation) and vertically lengthened as the bicuspid extraction
sites and the open bite are closed. This may cause the incisor
roots to come into heavy contact with the labial cortical
plate and thus result in so-called “round tripping.” Forces
must then be reapplied to the incisors to establish adequate
palatal root torque.
Effects on the Alveolar Ridge Height, the Cortical Plates,
and the Gingiva
When teeth naturally erupt, they bring alveolar bone
with them. It is also known that teeth may overerupt and
cause excess alveolar bone height. For example, in the
presence of a constant open mouth posture during growth,
the hypereruption of the maxillary molars will occur (see
Chapter 4). This defines the long face growth pattern
(see Chapter 21).92-97 One argument for functional appli­
ance use is to limit this molar hypereruption. The reverse
In theory, the optimal force level for the orthodontic
movement of a tooth is the lightest force (and the resulting
pressure) needed to produce the near-maximum preferred
response.176 Forces that are more than “optimal”—although
effective for the production of tooth movement—are both
unnecessary and possibly traumatic to the tooth, the peri­
odontium, the alveolar ridge height, and the cortical plates.
Negative Sequelae of Orthodontic Forces
Mobility and Pain
During the usual orthodontic movement of teeth, the PDL
fibers are stretched on the tension side, which is seen radio­
graphically as a widened PDL space. At the same time, the
PDL fibers are compressed on the pressure side, which
results in a narrowed PDL space. If forces are excessive,
greater degrees of tooth mobility can be anticipated, and
this will also involve a complaint of pain from the patient.
A similar sequence of events can occur with heavy clenching
or grinding of the teeth or in the presence of a traumatic
occlusion, which results in excessive force to individual
teeth. Excessive mobility will generally correct itself if the
force is removed quickly enough.
Heavy pressure applied to the tooth will also result in
immediate pain transmitted through the nerve fibers in the
PDL. Several hours after normal orthodontic forces are first
applied, teeth typically have at least some sensitivity to pres­
sure, such as with the biting of hard objects. Within 2 to 4
days, the pain should dissipate considerably. With current
therapeutic orthodontic mechanics, the forces applied
should result in very little immediate discomfort.
Effects on the Pulp
The normal therapeutic level of sustained light orthodontic
forces on the crowns of the teeth should have little effect
on the pulp. The loss of tooth vitality during orthodontic
treatment has occasionally been reported in previously trau­
matized teeth. This should be a rare consequence of ortho­
dontic therapy when light continuous forces are being
applied.
Effects on Root Structure
Recent research indicates that, when therapeutic orthodon­
tic forces are applied, there is a degree of injury to the
cementum. In current clinical practice, with the use of
continuous light forces, this occurrence is less frequent. The
repair of any limited cemental injury generally occurs.
Alternatively, heavy orthodontic forces—whether continu­
ous or intermittent—may lead to root resorption, because
the cementoclasts remove not only cementum but also
dentin of the root (Fig. 5-5). The permanent loss of root
structure only occurs when an island of cementum and
dentin becomes completely separated from the rest of the
root surface. When this happens, resorption without rein­
corporation occurs.34,37,84,103,121 The permanent loss of root
structure related to orthodontic treatment is generally seen
at the root apex.
Text continued on p. 156

145
CHAPTER 5  Orthodontic Considerations in the Evaluation and Treatment of Dentofacial Deformities
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A
B
• Figure 5-5  A 14-year-old girl was referred by her orthodontist for surgical evaluation. She presented
with a jaw deformity and associated malocclusion characterized by maxillary deficiency in combination
with asymmetrical mandibular excess. She is congenitally missing teeth (all of the third molars, the
maxillary right second molar, the maxillary left second molar, the mandibular left second bicuspid, and
the mandibular right second bicuspid), and she has short dental roots. At the time of arrival, she had
already undergone attempts at growth modification, including a face mask followed by rapid palatal
expansion. At presentation, there was an asymmetrical Angle Class III negative overjet with a bilateral
posterior crossbite malocclusion. Current maxillofacial dysmorphology and dental anomalies have
negative consequences on the patient’s speech, swallowing, breathing, chewing, and lip closure/
posture. At this time, the patient agreed to a comprehensive facial and dental rehabilitation approach
with a desire to achieve improvements in breathing, lip closure/posture, occlusion, long-term dental
health, and enhanced aesthetics. After periodontal and restorative dental evaluation, limited orthodon­
tics and then jaw and intranasal procedures were carried out. The procedures included a Le Fort I
osteotomy, sagittal ramus osteotomies of the mandible, an osseous genioplasty, a septoplasty, and
inferior turbinate reduction. With finishing orthodontics, restorative dentistry is planned. A, Frontal views
in repose before and after surgery. B, Frontal views with smile before and after surgery.
Continued

146
SECTION 1  Basic Principles and Concepts
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g atatatatatatatatatatatatatatatatatatatatatatatatatatatatatata hicicicicicicicicicicicicicicicicicici Su
Su
Su
Su
Su
Su
Su
S rg
r ery
ry
ry; J.C.
C Pos
os
os
os
os
os
os
os
os
osnicicicicicicicicick
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orthththththththththththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatatata hicicicicicicicicicicicicicicicicicicicici Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
S rg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C.
C Pos
os
os
os
o nicicicici k
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orthththththththththththththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatatatatatatatatatatata hicicicicicicicicicicicicicicicicicicicicicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
r ; J.C.
C.
C.
C.
C Pos
os
os
os
os
osnicicicicicick
C
D
• Figure 5-5, cont’d  C, Oblique facial views before and after surgery. D, Profile views before and
after surgery.

147
CHAPTER 5  Orthodontic Considerations in the Evaluation and Treatment of Dentofacial Deformities
• Figure 5-5, cont’d 
E
Prior to retreatment
After surgery and prior to further restorative dental procedures.
Pre surgery
E, Occlusal views before retreatment, with orthodontics in progress, and then after surgery but before final
restorative work.
Continued

148
SECTION 1  Basic Principles and Concepts
Maxillary clockwise
rotation
Mandibular clockwise
rotation
F
G
F, Articulated dental casts that indicate analytic model planning. G, Lateral cepha­
lometric radiographs before and after surgery.
• Figure 5-5, cont’d

149
CHAPTER 5  Orthodontic Considerations in the Evaluation and Treatment of Dentofacial Deformities
Before treatment
After surgery
H
H, Panoramic radiographs before retreatment and after surgery.
• Figure 5-5, cont’d

150
SECTION 1  Basic Principles and Concepts
Or
Or
Or
Or
O thththth
r ogn
gn
gn
gn
gn
gn
gn
gn
g atatatathicicicicicic Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry
r ; J.C.
C Pos
os
os
os
os
os
os
os
os
os
osnicick
Or
Orththth
r ogn
gn
gn
gn
gn
g atatatatatathicicicicic Su
Su
Su
Su
Su
Su
Su
S rg
r ery
ry
ry
ry
ry
r ; J.C.
C.
C.
C Pos
os
os
o nicicicicicicicicici k
Or
Or
Orththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatathicicici Su
Su
S rg
r ery
ry
r ; J.C.
C.
C.
C Pos
os
os
os
os
o nicicicici k
Or
Orthth
r ogn
gn
gn
gn
gn
gn
gn
g atatatatathicic Su
Su
Su
Su
Su
S rg
r ery
ry
ry
ry; J.C.
C.
C Pos
os
os
os
os
o nicicicicick
A
B
• Figure 5-6  A 20-year-old woman was referred by her orthodontist for surgical evaluation. She
presented with a narrow maxilla, a significant curve of Spee, and dental crowding. The mandibular
arch also had dental crowding, tipping, and rotations. Both jaws lacked horizontal projection, and
there was a severe anterior open bite malocclusion. The patient was a forced mouth breather with
increased nasal airway resistance as a result of septal deviation, enlarged inferior turbinates, and a
high nasal floor. The right maxillary lateral incisor was congenitally absent, and the left maxillary lateral
incisor was hypoplastic and rudimentary. The shortness of the roots throughout the maxillary and
mandibular dentition is presumed to be congenital. The patient agreed to a comprehensive facial and
dental rehabilitation approach with a desire to achieve improvements in breathing, lip closure/posture,
occlusion, long-term dental health, and enhanced aesthetics. She underwent periodontal treatment
that included the extraction of tooth no. 10, grafting to the labial aspects of the mandibular incisors,
and maxillary gingivectomy. This was followed by limited orthodontic manipulation and then jaw and
intranasal surgery. The procedures included a maxillary Le Fort I osteotomy in three segments (hori­
zontal advancement, vertical shortening, clockwise rotation, arch expansion, and the correction of
the curve of Spee); bilateral sagittal split osteotomies of the mandible (horizontal advancement and
counterclockwise rotation); osseous genioplasty (horizontal advancement and vertical shortening);
and septoplasty/inferior turbinate reduction. A, Frontal views in repose before and after treatment.
B, Frontal views with smile before and after treatment.

151
CHAPTER 5  Orthodontic Considerations in the Evaluation and Treatment of Dentofacial Deformities
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
O thththththththththththththththththththtr ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatatatatatatatatatata hicicicicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry; J.C.
C.
C.
C.
C Pos
os
os
o nicick
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orththththththththththththtr ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatathicicicicicicicicicicicicicicici Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry; J.C.
C.
C. Pos
os
o nicick
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orthththththththththththththththththththththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatatatatatatatatatathicicicicicicicicicicicicicici Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry; J.C.
C.
C Pos
osnicici k
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
O ththththththththththththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatatata hicicicicicicicicicicicicicicicicici Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
S rg
r ery
ry
ry
ry; J.C.
C Pos
o nicick
C
D
C, Oblique facial views before and after treatment. D, Profile views before and
after treatment.
• Figure 5-6, cont’d 
Continued

152
SECTION 1  Basic Principles and Concepts
E
Prior to retreatment
After treatment
Pre surgery
E, Occlusal views before treatment, with orthodontics in progress, and after treatment.
• Figure 5-6, cont’d

153
CHAPTER 5  Orthodontic Considerations in the Evaluation and Treatment of Dentofacial Deformities
F
G
Maxillary clockwise
rotation
Arch expansion
Mandibular counter-
clockwise rotation
F, Articulated dental casts that indicate analytic model planning. G, Lateral cephalometric
radiographs before and after surgery.
• Figure 5-6, cont’d 
Continued

Or
Or
Or
Or
Orththththththththththtr ogn
gn
gn
gn
gn
gn
gn
gn
g atatatathicicicicicicicicic Su
Su
Su
Su
S rg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C. Pos
os
os
os
os
os
os
os
os
os
osnicick
A
H, Sequential panoramic radiographs before retreatment and then after surgery.
H
Prior to retreatment
After surgery
• Figure 5-6, cont’d 
• Figure 5-7  A 25-year-old man with a long face growth pattern. He underwent a first-stage surgically assisted rapid
palatal expansion (SARPE) procedure to expand the maxillary arch width at another institution. There was a need for
definitive orthognathic correction, which was carried out by this surgeon in conjunction with continued orthodontic
treatment. A, Frontal facial view and occlusal views after SARPE procedure and before definitive orthognathic
correction.

155
CHAPTER 5  Orthodontic Considerations in the Evaluation and Treatment of Dentofacial Deformities
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
O ththththththththththtr ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatathicicicicicicicicici Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C Pos
os
os
os
osnicicicick
B
C
Prior to definitive treatment
D
Prior to retreatment
B, Profile facial and cephalometric views after SARPE procedure and before further
treatment. C, Panorex radiograph after SARPE. D, Periapical radiographs of anterior dentition before
further treatment. A degree of root resorption of the anterior dentition had occurred after the SARPE
procedure and before definitive orthognathic correction.
• Figure 5-7, cont’d

156
SECTION 1  Basic Principles and Concepts
Mechanical Techniques Used in Orthodontic
Force Control
Orthodontic tooth movement is best produced by light
continuous force. Orthodontic appliances in clinical practice
strive to use light continuous forces that are neither too
great nor too variable over time.156 The use of sound
mechanical principles; an understanding of the available
options with regard to materials, appliance design, and
anchorage control; and the prevention of a rapid decrease
in the orthodontic forces are more or less achievable.
The potential response of each tooth to the mechanical
forces that can be orthodontically applied (e.g., elastic
modules, wires, springs) must be considered by the clinician
when he or she is designing appliances (e.g., fixed, remov­
able) and then orchestrating anticipated dental changes. The
orthodontist delivers mechanical therapy with the place­
ment of brackets and bands on the teeth; the use of wires
that connect teeth together; the use of springs, coils, and
elastics; and with dental and non-dental anchorage control.
However, this is always done with an understanding of the
overall clinical objectives and pitfalls of treatment.
At times, it may be tempting to pursue an improved
occlusion by moving teeth outside of the alveolar housing
rather than coordinating treatment with either needed
orthognathic procedures or with selective extractions to
create necessary space40,74,98,124,137,219,235 (see Figs. 5-3 and
5-4). These two biologic treatment pitfalls contribute to
many of the everyday frustrations that are experienced in
clinical practice.31,41,47,60-62,67,132,133,149,168,195,212,214 The ortho­
dontist should remain vigilant when assessing the degree of
dental compensation introduced while attempting to correct
the occlusion.2,24,42,65,82,169,170,194,196,206
Fixed Appliances Used in
Orthodontic Treatment
Edward Angle is considered the father of modern orthodon­
tics (see Chapter 2). His treatment was based on the
development of appliances from which all contemporary
orthodontics stem.15,16,138,228 Current fixed appliances in
orthodontics are all variations of Angle’s edgewise appliance
system.36,112,233 By the late 1800s, orthodontic fixed appli­
ances depended on a rigid framework that was positioned
on the outside circumference of the teeth.214 The teeth were
then tied to the rigid framework to move them out to the
desired arch form (i.e., expansion) as dictated by the appli­
ance. Angle’s “E” arch was an innovation on earlier designs.
Bands were placed on the molar teeth, and a heavy U-shaped
arch wire was attached to the banded molars posteriorly. The
arch wire was positioned around the labial side of the indi­
vidual teeth, which were then ligated to it. The wire was
gradually unscrewed at the molar location, which resulted
in expansion as the arch perimeter increased. The teeth were
forced to expand with the labial wire. Unfortunately, the
“E” arch was only capable of tipping the teeth into the new
effect on the alveolar process is observed at the edentulous
space of a congenitally absent tooth (e.g., a retained primary
molar with the congenital absence of a mandibular per­
manent bicuspid). The associated alveolar bone will be
concave with limited vertical height (Fig. 5-8). The alveolar
ridge volume deficiency at the edentulous site will also
have a ripple effect, thereby preventing the full eruption
of the adjacent teeth. Another example in which ridge
height and volume is affected is when a maxillary canine
erupts into a successfully bone-grafted alveolar cleft. Typi­
cally, the canine eruption followed by the orthodontic
closure of the cleft dental gap will achieve normal vertical
height and an improved arch form (see Chapters 32 and
33; Fig. 5-9).
It is also known that, if a tooth is orthodontically
intruded, alveolar height will be lost, thereby leaving the
same amount of root embedded in the bone as before (i.e.,
the reverse effect of hypereruption). In this clinical scenario,
the movement of the intruded tooth’s gingival margin rela­
tive to the surrounding teeth will also be observed. TADs
and other orthodontic means are often used in an attempt
to achieve this objective. Unfortunately, the relapse tenden­
cies after these orthodontic maneuvers remain a concern.
Teeth can generally be orthodontically moved through
the alveolus without significant damage being done to the
bone.71,155 The essential point is to move the tooth through
the alveolus rather than outside of it. An exception to this
is seen in the presence of active periodontal disease or when
the orthodontic forces applied are excessive.128 In this sce­
nario, remodeling with a loss of crestal height and cortical
wall dehiscence are likely negative effects to the alveolar
bone. If the periodontal disease is first controlled, a normal
bone response to therapeutic orthodontic mechanics should
be expected (see Chapter 6).26
Before orthodontic treatment is initiated, the individual’s
biotype (i.e., the biologic predisposition of the periodon­
tium) should be considered.3,87 This includes an assessment
of the adequacy of the gingiva and the alveolus. A thick
attachment apparatus and a full-volume alveolus are desired.
In an adult (even more so than in a teenager), the movement
of teeth outside of the alveolar bone housing or without
adequate attached gingiva is poorly tolerated (see Figs. 5-3
and 5-4). In addition, the extrusion of the incisors, the
buccal tipping of the maxillary molars, and the labial version
of the mandibular incisors should be limited. The adult
dentition may also be compromised by wear abrasion facets,
the presence of poorly designed and poorly fitted restora­
tions, and the pretreatment loss of the periodontium. In
addition to standard orthodontics, ideal treatment may
require the following: (1) periodontal evaluation and man­
agement; (2) the completion of functional restorations; (3)
the surgical correction of any existing jaw discrepancy; and
(4) the management of edentulous space. Clarifying the
willingness of the patient to maintain a hygiene program
before the initiation of treatment is also a benchmark
requirement to ensure success.

• Figure 5-8  This 22-year-old man is congenitally missing the mandibular first and second bicuspids and the right
maxillary first bicuspid. He has a maxillary deficiency in combination with relative mandibular excess. He underwent
earlier compensating orthodontic treatment, but an Angle Class III, negative overjet, posterior crossbite malocclusion
remains. With the congenital absence of the permanent lower bicuspid teeth, there is hypoplasia of the associated
alveolar ridge. The congenital absence of the bicuspids causes a ripple effect on the vertical alveolar height of the
adjacent teeth. A, Frontal facial view and occlusal views before definitive orthognathic correction and dental reha­
bilitation. B, Profile facial and cephalometric views before further treatment. C, Panorex radiograph before further
treatment.
Or
Or
Or
Or
Or
Or
Orthththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatata hicici Su
Su
S rg
r ery
ry
r ; J.C.
C.
C.
C.
C Pos
os
os
os
os
os
os
o nicicicicicicicicick
A
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
O ththththththththththththththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatatatatatatathicicicicicicicicicicicicici Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry; J.C.
C.
C Pos
osnicick
B
C

158
SECTION 1  Basic Principles and Concepts
Or
Or
Or
O ththth
r ogn
gn
gn
gn
gn
gnatatatatata hicici Su
Su
S rg
r ery
ry
ry; J.C.
C.
C.
C.
C.
C. Pos
os
os
os
os
os
os
os
os
os
os
o nici k
Or
Or
Orththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatathicicicicicicicici Su
Su
Su
Su
Su
Surg
r ery
ry
ry; J.C.
C.
C.
C Pos
os
os
os
os
os
os
os
o nicicicicici k
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orththththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gnatatatatatatatatatatatathicicicicicicicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C.
C.
C.
C.
C.
C.
C.
C.
C. Pos
os
os
os
os
os
os
os
os
os
osnicici k
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orththththththththththtr ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatathicicicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C.
C.
C.
C.
C.
C.
C Pos
os
os
os
os
o nicicicick
A
B
• Figure 5-9  A child who was born with van der Woude syndrome, including bilateral cleft lip and
palate and lower lip pits, was followed since birth by this surgeon. The child underwent lip and palate
repair, including lower lip pit excisions, during childhood. He underwent successful mixed dentition
grafting and fistula closure before the eruption of the canines. As a teenager, he demonstrated maxil­
lary hypoplasia with secondary deformities of the mandible. He then underwent a comprehensive
orthodontic and orthognathic/intranasal surgical approach that included a standard Le Fort I oste­
otomy (vertical lengthening, horizontal advancement, and clockwise rotation) with interpositional
grafting; bilateral sagittal split ramus osteotomies (clockwise rotation); osseous genioplasty (horizontal
advancement); and septoplasty/inferior turbinate reduction/nasal floor recontouring (see Fig 33-3).
A, Frontal views with smile before and after reconstruction. B, Profile views before and after
reconstruction.

159
CHAPTER 5  Orthodontic Considerations in the Evaluation and Treatment of Dentofacial Deformities
C
Mixed dention prior to bone grafting
Pre orthognathic surgery after successful bone grafting and orthodontic closure of cleft dental gaps
After treatment
• Figure 5-9, cont’d  C, Occlusal views before mixed dentition bone grafting and fistula closure, with orthodontics in progress before
orthognathic surgery, and then after the completion of reconstruction. The placement of a dental implant for the congenitally missing
right maxillary bicuspid is planned for when the patient reaches 18 years of age.
Continued

160
SECTION 1  Basic Principles and Concepts
alignment of malpositioned teeth. Unfortunately, these
appliances still did not achieve consistent bodily movement
of the teeth. Tipping of the teeth continued to be problem­
atic. To overcome the deficiencies of the ribbon arch, Angle
reoriented the slot (i.e., the shape and location of the bracket
on the labial side of each banded tooth) from vertical to
horizontal and then inserted a rectangular labial arch wire.
He also coined the term edgewise. The edgewise appliance
allowed for the improved control of crown and root posi­
tioning in all three planes of space. By the early 1930s,
Angle’s edgewise appliance became the mainstay of fixed
orthodontic appliance therapy.222 The rectangular arch wire
was tied into a rectangular slot on the labial side of each
tooth with additional wire ligatures; pins were no longer
used. This further improved the control of the root position
(i.e., it limited tipping) during the movement of the teeth.
position. In addition, it could not precisely differentially
position individual teeth over the dental arch. Angle then
began to band each individual tooth (not just the molars),
and he refined the connection of each banded tooth to the
labial arch wire. This allowed him to move each tooth
toward the wire at different rates to round out the arch. This
technique required ingenuity and a sophisticated mechani­
cal understanding of the process. Accomplishing these
maneuvers had a steep learning curve, and it was not easily
grasped by clinicians in practice. Angle’s next appliance
innovation modified the tube (band) that was placed around
individual teeth to include a vertically positioned rectangu­
lar slot. The ribbon arch was made of gold wire, and it
remained on the labial side of the arch.63 The gold wire was
inserted into the slot (bracket) on each banded tooth and
held in place with a pin. This improved the efficiency of the
D
After orthognathic surgery
Mixed dentition — prior to grafting
L
R
• Figure 5-9, cont’d  D, Panorex radiographs of the mixed dentition before cleft bone grafting and then
after orthognathic reconstruction. With effective bone grafting of the clefts in the mixed dentition followed
by orthodontic closure of the cleft dental gaps, the maxillary canines and central incisors achieved a
normal alveolar ridge and periodontium.

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CHAPTER 5  Orthodontic Considerations in the Evaluation and Treatment of Dentofacial Deformities
hooks; and (4) lingual arch attachments. Headgear tubes
can accept heavy auxiliary labial arch wires. Auxiliary edge­
wise tubes allow for the application of segmental arch
mechanics. They are generally used for the intrusion of
teeth, and they are placed gingival to the plane of the main
arch wire. Auxiliary labial hooks can be used for intra-arch
elastics, but they require meticulous oral hygiene. Lingual
arch attachments can also be used for adjunct anchorage
control.
Bracket Materials and Design
Orthodontic brackets are generally made from various
classes of stainless steel.99,112,140 More often than not, they
are made by a metal injection molding process rather than
milling. Clear brackets that are made of reinforced resin
composite or alumina have become popular; this aesthetic
option is often requested by the patient. Friction forces
created between metal arch wires and ceramic brackets have
largely been overcome by designs that incorporate a metal
slot in the bracket or by reducing surface roughness within
the slot. Self-ligating brackets are classified as either passive
or active, depending on how the wire is held in the bracket
slot. Both types of self-ligating brackets can offer low fric­
tion with a reduction in the anchorage requirements and
less chair time without a loss in the quality of the results.
The term prescription is used in orthodontics to describe the
angulation, inclination, and offset values used in the bracket
system to treat a particular patient’s malocclusion. Tradi­
tional prescriptions have been based on the systems of either
Roth or Andrews, although many variations exist.12-14,190,191
Current prescriptions often use newer arch wire and bracket
technology and involve claims of improved treatment effi­
ciency. For example, SureSmile uses a variety of prescription
brackets in conjunction with computer-generated, pre-bent
prescription wires for faster and more accurate detailing and
finishing. The Insignia system also uses a computer to mill
special brackets for each tooth of each patient. The brackets
are then bonded indirectly to each tooth with the use of
transfer jigs. The Incognito system creates custom-made gold
brackets for lingual orthodontics. This method of tooth
movement has gained popularity in Europe, and it is also
used in the United States. Problems with all of these pre­
scription techniques may arise if they are improperly used
by a clinician for an individual with a jaw deformity. If
attempts are made to correct the malocclusion by ortho­
dontic mechanics alone, the preset wires will result in exces­
sive dental compensation with injury to the dentition and
the surrounding periodontium as the teeth are compressed
against the cortical plates and pulled out of the alveolar
housing. However, when properly incorporated into a com­
prehensive orthodontic and orthognathic treatment plan,
these newer techniques may improve results and involve
reduced treatment times.
The banding of individual teeth has been used in ortho­
dontics for more than 100 years as a method to gain attach­
ment to the teeth. With the introduction of the acid-etch
technique, the anterior teeth, as part of orthodontic therapy,
Eyelets were added to the corners of the bands on each
tooth, which could be tied into the labial arch wire as
needed for rotation control. Angle was the first clinician to
place attachments on each individual tooth to achieve the
precise repositioning of each tooth toward a labial arch wire.
Interestingly, Angle’s edgewise appliance system was also
able to provide the level of control of root position that was
necessary during the process of tooth movement to close an
extraction site. If Angle had known that his appliance would
be used in this way, he likely would have prevented its
development. Charles Tweed, who was initially an Angle
disciple, adapted the edgewise appliance for this purpose.214
He did so after he observed significant relapse in many of
his own non-extraction (i.e., arch expansion) cases. After he
made a decision in favor of extraction, he was able to move
the teeth bodily into the bicuspid extraction site with molar
anchorage control. The teeth were then able to be retracted
into the extraction sites with closing loops, one at a time
(canines first, incisors second). In Australia, Begg adopted
the ribbon arch appliance (rather than the rectangular wire)
to close extraction sites.223 He felt that it provided better
control of the root position. He first tipped the anterior
teeth with light continuous forces and then used torquing
and uprighting auxiliaries to complete tooth alignment.
When this was coupled with the detorquing of the incisors,
root resorption sometimes occurred.
Orthodontic appliances were further modified to allow
for rotational control without the need for additional
ligatures.11-14,54,107,108,111,190,191 This was accomplished by
using either twin brackets or extension wings with single
brackets that could contact the underside of the arch wire.
Further modifications included the alteration of the bracket
slot dimension, self-ligating brackets, and the addition of
lingual appliances. With improvements in dental materials,
bonding attachments (i.e., brackets) that were applied directly
to the tooth surface (rather than the banding of teeth)
became popular. Bonded attachments have no interproxi­
mal component and therefore require no separation of
teeth, and they are less painful for the patient. They are
more efficient for the clinician to put on and to remove,
and they are more aesthetic because they are less visible
to the casual observer at conversational distance. Clear
and tooth-colored appliances have also been developed.
An additional advantage to direct bonded brackets and
tubes is improved access for oral hygiene and periodontal
maintenance.
Contemporary edgewise appliances still remain an inte­
gral component of orthodontic treatment.99 Brackets or
tubes are customized for each individual tooth, thereby
allowing for the minimum number of bends in the arch
wire that are necessary to produce an ideal arrangement of
the teeth. This “straight wire” approach requires some
bending of the wire to allow for a passive fit of the arch wire
when the teeth are ideally aligned.
Auxiliary attachments are components of the edgewise
appliance system and include the following: (1) headgear
tubes; (2) auxiliary edgewise tubes; (3) auxiliary labial

162
SECTION 1  Basic Principles and Concepts
alloys surpassed gold as the preferred arch wire materials
during the 1940s to reduce costs, to provide higher-yield
strength and stiffness, and to result in higher elastic modulus
and flexibility with improved properties to orthodontically
close dental space. These alloys generally included platinum
and palladium, which were often mixed with gold and
copper. During the 1970s, NASA developed a nickel-
titanium alloy that was easily deformed at low temperatures
but that was able to memorize its original shape with
warming (i.e., the thermal dynamic shape memory effect).
The term active has been coined to describe this phenom­
enon. Nitinol was then developed as a cheaper, stabilizing
“passive” version of this material, and it has been found to
be useful as an orthodontic wire, because it still possessed
low stiffness and good recovery when it was used as an
aligning or intermediate arch wire. Currently, two active
nickel-titanium alloy forms of this material are used in
orthodontic practice, because they both possess excellent
elastic properties. This includes the strength-induced super­
elastic wires and the thermally induced superelastic wires. The
term superelastic refers to a material that can undergo
martensite-austenite phase transformations, which are gen­
erated by either mechanical stress or heat. The crystal struc­
ture of the wire changes with mechanical deformation,
which results in a unique non-linear stress–strain curve in
which stress is independent of applied strain. In theory, the
force levels that are used to deform the wire to ligate it into
the bracket are less than those created by the wire as it
attempts to return to its original shape. This offers the
advantage of low continuous forces applied to the teeth
through the entire reforming process, despite the wire being
tied into teeth that are severely displaced. The thermally
induced superelastic wire undergoes phase change as the
temperature changes from the ambient temperature to an
individual’s body temperature. The temperature at which
the transformation takes place can be specifically controlled
during the manufacturing process to match the intraoral
temperature requirements. When using thermally induced
superelastic wires, the wire is ligated in place during its
low-stiffness phase; then, with the heat of the oral cavity,
transformation is induced, thereby returning it to its prede­
termined austenitic form. The theoretical advantage of both
of these superelastic wire types is that they are able to
provide a physiologic low and continuous force that can be
used for leveling and aligning the teeth. Although individ­
ual practitioners are advocates of these wires as compared
with the more traditional nickel titanium or multi-strand
stainless steel wires, significant differences in the speed of
alignment between the wire types has yet to be proven.42
Intra-Oral Auxiliaries to Brackets and Arch Wires
Intra-oral auxiliaries to the brackets and arch wires include
closing and opening coils, torquing and uprighting auxilia­
ries, elastomeric chains, other non-compliance devices, and
temporary skeletal implants. Elastomeric modules are com­
monly used to secure the arch wire into the slot of a non–
self-ligating bracket.
are commonly bonded rather than banded. The bonding
of molar teeth has also become more common in clinical
practice, which is due at least in part to improvements in
light-cured adhesive technology and bracket design (i.e., a
contoured bracket design and a micromesh base). In addi­
tion, the cost of bonded molar tubes has come down, and
the avoidance of molar banding means that the separation
of the teeth for the placement of the bands is no longer
required.
Cements and Adhesives
The spectrum of cements and adhesives used in orthodontic
practice includes self-etching primers, wet bonding, fluoride
release to prevent demineralization, light-cured band
cements, colored cements, and curing lights.* Self-etching
primers are now available for orthodontics. They are rela­
tively moisture insensitive, but they may have reduced bond
strength as compared with the conventional acid-etch tech­
nique. The wet bonding products (i.e., modified resin-filled
glass ionomer adhesives) that are currently available show
lower bond strengths with a higher failure rate than con­
ventional composite, but they are generally acceptable for
accomplishing needed objectives. Fixed-appliance ortho­
dontics can lead to problems with oral hygiene, increased
plaque accumulation, and altered plaque ecology, which
may lead to enamel demineralization. Fluoride in the oral
environment has been shown to lead to altered bacterial
function, reduced enamel dissolution, and increased remin­
eralization. Fluoride-releasing bonding cements have been
shown to reduce the depth and extent of demineralization
microscopically. Unfortunately, long-term success with
regard to the limiting of demineralization has not been
significantly demonstrated. Conventional glass ionomers are
still the preferred material for use beneath molar bands to
limit demineralization as compared with cements that do
not release fluoride. Polyacid-modified composite cements
are now available to secure bands, and they offer a light-
cured snap set. These new cements appear to clinically
perform as well as conventional glass ionomer cement, but,
because they do not bond to enamel, they may result in
greater demineralization in some patients. High-performance
halogen curing lights are now available; these contain bulbs
that do not degrade over time, and they have curing times
of 5 to 8 seconds. Plasma arc lights are also available; these
can cure adhesive in 3 to 5 seconds, but they have the dis­
advantage of generating much heat during the process. Cur­
rently available light-emitting diode curing lights are gaining
popularity; they generate low levels of heat, and they are
cordless.
Arch Wire (Materials and Design)
Before the 1950s, precious metal alloys were the commonly
used materials for orthodontic arch wires. Stainless steel
*References 10, 38, 51, 56, 105, 120, 144, 145, 153, 154, 172, 173, 177,
202-204, 232, 236

163
CHAPTER 5  Orthodontic Considerations in the Evaluation and Treatment of Dentofacial Deformities
often circumvent the need for devices that require patient
compliance. There is more information about TADs later
in this chapter.
Removable Appliances Used in
Orthodontic Treatment
The use of removable appliances to guide tooth movement
has a long history and persuasive clinical advocates. There
have been periods of intense use followed by waning inter­
est. During the late 19th and early 20th centuries, the use
of fixed appliances was limited by available materials, the
need for labor-intensive “chair time,” and an incomplete
mechanical understanding of their potential by most clini­
cians. Removable orthodontic appliances have several
immediate advantages, including that they can be fabricated
in a laboratory (thereby reducing “chair time” for both the
patient and the dentist) and that they can be removed at
socially sensitive times or to make oral hygiene easier.
Removable appliances that are used for the movement of
teeth have disadvantages, including their dependence on
consistent patient compliance. They are difficult to con­
struct, thus making precise complex tooth movements
problematic. Even with excellent patient compliance, carry­
ing out complex tooth movement remains an issue.
During the early 1900s, removable upper and lower arch
appliances used to produce the desired tooth movement
were often made of heavy gold wires as a framework from
which lighter gold finger springs were placed. The first
molars were banded, and wire ligatures were used to tie in
heavy labial and lingual arch wires. Interestingly, the use of
removable appliances for the movement of teeth was favored
in Europe during the first half of the 20th century. This was
primarily for economic reasons, and there was a lack of a
strong clinical advocate for fixed appliances on that side of
the Atlantic. During the same time frame, Edward Angle’s
profound influence on clinicians in the United States
encouraged the preferred use of the edgewise fixed appliance
system.
Functional appliances represent a second category of
removable design (although they may also be fixed). They
are constructed primarily with the hope of changing the
position of the mandible (i.e., to hold the lower jaw open
and to posture it forward) as well as to limit or enhance the
eruption of maxillary molars. The history of functional
appliances can be traced back to the mid 1800s, when
Norman Kingsley introduced the “bite-jump” appliance
(1879).114 The “monobloc,” which was developed by Robin
in the United States during the early 1900s, was followed
by the “activator,” which was developed in Norway by
Andresen during the 1920s; both of these devices became
widely accepted. Harvold reintroduced removable func­
tional appliances to North American orthodontists during
the 1960s, around the same time that the use of fixed appli­
ances finally began to catch on throughout Europe. Har­
vold’s animal model studies confirmed that mandibular
posture did in fact affect maxillomandibular growth92-97 (see
The definition of friction is the resistive force between
surfaces that oppose motion. In orthodontic tooth move­
ment, friction results from the interaction of an arch wire
with the walls of an orthodontic bracket or a ligature. It is
now known that friction is only a small part of the resistance
to movement as a bracket slides along in arch wire.19,39,64,122,208
In orthodontics, tooth and bracket movements have major
interactions that involve the teeth, the PDLs, the alveolar
bone, and the forces of mastication. For a bracket that is
attached to a tooth to move relative to a wire in the bracket
slot, the tooth must move. The tooth’s resistance to being
moved contributes to its resistance to sliding. This is par­
ticularly true when bodily movement rather than tipping is
desired. Binding and notching will occur in the clinical
setting but not in laboratory simulations, where only brack­
ets and wires are involved. In review, clinical studies and the
analysis of laboratory findings support the view that, in
orthodontic practice, resistance to sliding has little to do
with friction and instead is largely a binding-and-release
phenomenon. Interestingly, resistance to sliding is about the
same with both conventional and self-ligating brackets.39
Space closure with Angle and Tweed edgewise mechanics
requires closing loops that involve the use of rectangular
steel arch wires. Many clinicians prefer to use edgewise
mechanics, because they provide for friction-free tooth
movement. Significant disadvantages of this approach
include (1) the time required to bend the wires; (2) the need
to apply heavy forces across the extraction spaces; and (3)
the fact that only a short time range of activation is possible,
thus requiring frequent patient appointments. Since the
1990s, sliding mechanics have been used as part of various
attempts to decrease the amount of force that is required to
close space. The sliding technique for space closure generally
uses either elastomeric chains or modules in coil springs.
The elastomeric chain was introduced during the 1960s. It
has the advantage of being inexpensive, but it suffers from
rapid force decay of between 50% and 70% during the first
24 hours. The introduction of space-closing coil springs,
which were originally made of stainless steel and cobalt–
chromium–nickel alloys and more recently replaced by
nickel–titanium springs, have less force decay as compared
with elastomeric springs (8% to 20% versus 50% to 70%).
Advocates for space closure with both techniques can be
found. Inexpensive elastomeric products are still often pre­
ferred, because they are generally effective.
In an ideal world, orthodontic treatment would require
no compliance from the patient. Unfortunately, removable
anchorage devices (e.g., cervical and reverse pull headgear,
intermaxillary elastics) are still required with various orth­
odontic maneuvers. The clinical use of intermaxillary trac­
tion with nickel titanium coil spring-and-piston cylinders
that are attached to a fixed appliance and used to hold the
mandible in a postured position are theoretically interest­
ing, but they involve frequent breakage problems. The use
of TADs (e.g., non-osseointegrated titanium micro-screws
or titanium plates held in place with screws) that are placed
directly into alveolar bone are now used for anchorage; these

164
SECTION 1  Basic Principles and Concepts
review, the study by Siara-Olds, et al. confirms that func­
tional appliances for the purpose of correcting micrognathia
have negligible impact on the growth potential of the man­
dible long term.
A third category of removable appliances are used for the
retention of the achieved orthodontic results. A spectrum
of retention appliance designs are used in everyday ortho­
dontic practice. With regard to the issue of retention,
Melsen stated the following: “We [orthodontists] deliver the
product, but the final result, as when you buy a car, depends
on life-long retention and life-long maintenance. Other
than diamonds, everything has to be maintained; true sta­
bility only occurs post mortem.”142
We can also add Invisalign, which is a product that
involves a series of removable clear aligners, as a fourth
category to the list of removable orthodontic appliances. It
is a method that is used for the purpose of orthodontic
tooth movement. Its current level of popularity is at least
partially the result of an effective worldwide marketing cam­
paign. Clinical judgment is required to determine when this
option is an appropriate form of treatment for the correc­
tion of specific—but limited—patterns of malocclusion.
Nevertheless, as of 2013, it is estimated that approximately
2 million individuals have completed or are currently receiv­
ing Invisalign treatment.
Accelerated Osteogenic Orthodontics
Finding a technique that enhances the speed of orthodontic
tooth movement without causing damage has been an
objective of clinicians for more than 100 years. Attempts to
modify the balance between resorption and deposition and
to bypass the waiting time for the alveolar cortex to resorb
and thus move the teeth faster without causing irreversible
damage to the periodontium has been the focus of much
research over the years.28,29,49,78,79,81,90,101,200,217,218,234 Corti­
cotomy, which is the intentional injury of the cortical bone,
was described in the mid 1800s as a surgical approach to
correct malocclusion. Osteotomies into the cortical alveolar
bone were made, and then the teeth were splinted into
new positions. This concept received renewed attention
when Kole published a series of clinical articles describing
a different approach to the treatment of orthodontic
patients.116,117 In 1975, Duker used a dog model to demon­
strate rapid segmental alveolar movement after corticot­
omy.68 In 1986, Anholm and colleagues also described
corticotomy-facilitated orthodontics in clinical practice.17
William and Thomas Wilcko further modified the protocol
for corticotomy-facilitated orthodontics; they trademarked
their technique in 1998.230,231 That same year, the Wilcko
brothers received an endorsement for their technique from
the American Academy of Periodontics. Their technique
involves elevating a full-thickness mucosal flap off of the
alveolar plate (either labial or lingual/palatal) directly over
the teeth to be moved. They then place corticotomies (per­
forations) through the alveolar bone adjacent to the teeth
Chapter 4). This led to a belief that functional appliances
could be used to “alter back” abnormal jaw growth tenden­
cies. During the 1970s, the Frankel regulator by Rolf
Frankel of East Germany popularized the concept of a
tissue-borne functional appliance. By the 1980s, William
Clark of Scotland introduced the Twin Block, which is a
two-piece, tooth-borne appliance. The Twin Block was
easier to wear than the Frankel regulator, and it was designed
to accomplish the same objectives. Pancherz then popular­
ized the Herbst fixed functional appliance during the 1980s,
because it circumvented the problem of patient compliance.
This appliance was originally developed by Emil Herbst at
the beginning of the 20th century. Proffit has stated that,
despite continued strong advocates of functional appliances,
“the results of human clinical trials and retrospective analysis
have not confirmed sufficient success with the use of functional
appliances to make them mainstay treatment.”210 Although
there is limited evidence-based research to support func­
tional appliances, their continued use in everyday orth­
odontic practice remains a reality.
Siara-Olds and colleagues recently completed a prospec­
tive, randomized, controlled clinical study to assess the early
and long-term treatment outcomes of tooth-borne func­
tional appliances.201 They tested the use of four different
functional appliances in a treatment group, and they also
followed a group of untreated control subjects with Class II
malocclusions. The treatment group (n = 80) was subdi­
vided evenly into four subgroups in accordance with the
type of functional appliance being used: the Bionator (n =
20); the Herbst fixed functional appliance (n = 20); the
Twin Block (n = 20); and the mandibular anterior reposi­
tioning appliance (n = 20). The functional appliance
treatment was carried out on individuals with Class II mal­
occlusions who were between the ages of 8 and 12 years.
Each randomized Class II malocclusion subject received
comprehensive orthodontic treatment with bands and
brackets to complete their treatment after the use of the
specific functional appliance. The investigators compared
lateral cephalometric radiographs that were taken at stan­
dard intervals (i.e., before treatment, after functional appli­
ance therapy, and after the completion of comprehensive
orthodontics). The four subgroups were also compared with
an untreated control group who had similar Class II maloc­
clusions who were not treated with functional appliances,
bands, or brackets. The results of the study confirmed that the
use of the functional appliances did not alter long-term man­
dibular growth patterns as compared with the results seen
among the control subjects with Class II malocclusions. Inter­
estingly, the use of a functional appliance in combination
with bands and brackets did demonstrate effects, including
the following: (1) the restriction of maxillary horizontal
growth; (2) the creation of a steeper occlusal plane (with
the Herbst and mandibular anterior repositioning appli­
ances); and (3) the steepening of the mandibular plane
angle (i.e., clockwise rotation) with the labial version of the
mandibular incisors with the Twin Block appliance.201 In

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CHAPTER 5  Orthodontic Considerations in the Evaluation and Treatment of Dentofacial Deformities
on the experimental (corticotomy) side, there was no hyaline
present in the periodontium, the socket wall had appropri­
ately resorbed, and the bicuspid tooth was able to move
mesially without root resorption.
In the rat model, Sebaoun and colleagues studied the
alveolar response to corticotomy as a function of time and
proximity to the surgical injury.197 Maxillary buccal and
palatal cortical plates were injured (corticotomy) in healthy
adult rats (n = 36) adjacent to the upper left first molars.
Twenty-four of the animals were euthanized at 3, 7, and 11
weeks after injury.
Histomorphometric analysis was performed to study
alveolar spongiosa and periodontal ligament dynamics. Both
catabolic activity and anabolic actions were also measured.
A separate group of animals (n = 12) were fed with calcein
fluorescent stain. After the same surgical and orthodontic
maneuvers, they were processed for non-decalcified fluores­
cent stain histology. The results of the study demonstrated
that, at 3 weeks, the surgical (corticotomy) group had sig­
nificantly less calcified spongiosa bone surface, greater peri­
odontal ligament surface, higher osteoclast number, and
greater lamina dura apposition width. The catabolic activity
(i.e., the osteoclast count) and the anabolic activity (i.e., the
apposition rate) increased by threefold, the calcified spon­
giosa bone surface decreased by twofold, and the PDL
surface increased by twofold in the corticotomy group.
Interestingly, the surgical injury to the alveolus (corticot­
omy) that induced a significant increase in tissue turnover
by week 3 dissipated to a steady state by postoperative week
11. In addition, the impact of the injury (rapid tooth move­
ment) was localized to the area immediately adjacent to the
decortication injury. The authors concluded that selective
alveolar decortication induced increased turnover of alveolar
spongiosa and that the activity was localized. The escalation
of demineralization–mineralization dynamics is the likely
biologic mechanism that explains the rapid tooth movement
that occurs after selective alveolar decortication.
In review, it appears that the completion of a corticot­
omy of the alveolar process immediately brings macro­
phages into the field of bony injury.116 The macrophages
are then able to remove the hyaline (necrotic material) from
the periodontium more quickly than occurs in a non-
corticotomy setting. The early presence of macrophages can
explain the rapid degree of bone resorption and minimal
root resorption during orthodontic tooth movement that
was documented by Lino and colleagues. When Lino’s
group compared the amount of tooth movement in their
experimental and control groups, the teeth on the corti­
cotomy side moved twice as fast as the teeth on the control
side. The enhanced tooth movement after corticotomy
should continue as long as the surgical site healing remains
in progress (only approximately 2 to 3 months). The poten­
tial for morbidity to the teeth and periodontium that is
associated with the surgical procedure, must be considered
in light of any advantage of reduced time to reach treatment
objectives.
to be moved with the use of a burr on a handpiece. The
Wilckos also recommend placing bone graft material over
the surgical perforations in the cortical plate to improve
alveolar volume. They then replace the mucosal flap into its
anatomic location with sutures. They further claim that the
technique enhances difficult tooth movement (i.e., molar
intrusion) and that it can provide relative anchorage (i.e.,
a corticotomy limited to the anterior region will provide
relative anchorage from the posterior teeth). The theory
behind this technique is that injury to the bone (i.e.,
the cortical perforations) creates a “regional acceleratory
phenomenon.”230As a result, the body rapidly sends cells to
the site to heal the injured bone. This surge in cellular
healing activity is thought to promote faster tooth move­
ment. The Wilckos called their technique accelerated osteo­
genic orthodontics.230
The animal research by Lino and colleagues130 and the
experimental study completed by Sebaoun and colleagues197
describe a plausible biologic explanation for the greater
speed of tooth movement that is seen with these techniques.
Lino’s group used adult beagle dogs (n = 12). The man­
dibular right and left first premolars were to be moved
mesially with the use of a calibrated spring that attached to
the mandibular canines. On one side of each mandible, a
flap was elevated, and holes were placed in the alveolar bone
(corticotomies) to create a regional acceleratory phenome­
non. No corticotomy was performed on the opposite
(control) side. The PDL on the mesial (compression) side
of each premolar was evaluated histologically at weeks 1, 2,
4, and 8. In addition, the amount of mesial bicuspid tooth
movement on each side (i.e., the experimental side versus
the control side) was compared at the 8-week interval. His­
tologic comparisons of the two sides showed very distinct
differences. At 1 week, bicuspid tooth compression pro­
duced a typical hyalinization of the PDL on both sides.
“Hyaline formation” within the PDL, which is referred to
as a “sterile necrosis,” occurs in response to compressive
forces. This is the expected response when significant com­
pressive forces are produced in the PDL. It is known that
this sterile necrosis interferes with bone resorption; thus, at
the 1-week interval, no tooth movement was experienced
on either side. At 2 weeks, hyaline was still present on the
control side, so no bone resorption of the tooth socket wall
had yet occurred; however, root resorption was evident. At
2 weeks, on the experimental (corticotomy) side, the hyaline
had already been removed from the PDL. Presumably, mac­
rophages (the presence of which had been stimulated by the
regional acceleratory phenomenon) were in place very early
to perform this removal and thus, in the process, no root
resorption occurred. At 4 and 8 weeks after the initiation
of treatment on the control (non-corticotomy) side, the
hyaline had finally been removed and the alveolar bone
resorption had begun, thereby allowing mesial bicuspid
tooth movement to proceed. During this waiting period,
extensive root resorption had occurred on the control side.
Interestingly, at the 4- and 8-week post-treatment intervals

166
SECTION 1  Basic Principles and Concepts
Temporary Skeletal Anchorage
in Orthodontics
TADs that are made of titanium and temporarily fixed into
alveolar bone have been shown to provide effective supple­
mental or “maximum” anchorage for the movement of teeth
while avoiding unwanted negative reciprocal responses
in the dentition.* Retromolar titanium (dental) implants
simply for the purpose of temporary skeletal anchorage to
facilitate orthodontic movement of the teeth were first
placed by Roberts and colleagues in 1989.185-187 Wehrbein
and Merz placed titanium implants directly into the hard
palate and then tied the molar teeth to them.224,225 The
purpose of the temporary hard-palate implants was to
prevent the movement of the molar teeth that were to be
used as direct anchorage for the distal movement of anterior
teeth into bicuspid extraction sites. Standard titanium bone
fixation plates (i.e., mini-plates) were next used as TADs.
The mini-plates were fixed to the zygomatic buttress with
titanium screws. The end of the titanium plate then perfo­
rated through the oral mucosa to provide a point of attach­
ment for orthodontic wires, springs, coils, and elastics.
Mini-plates and mini-screws made of titanium alloy are
becoming a frequent temporary source of skeletal anchorage
(i.e., TADs) for orthodontic tooth movement. Advantages
of these TADs include being relatively simple to place,
providing proximity for orthodontic attachments, allowing
for immediate loading, requiring no laboratory work, not
being socially embarrassing for the patient to use, and being
relatively low in cost. Alternatively, TAD use may be com­
plicated by early “loosening” or injury to the teeth and the
periodontium. Depending on their location of placement,
TADs may also provide vector challenges for accomplishing
the task at hand. Although the clinical role of TADs in
everyday orthodontic practice has not yet been fully clari­
fied, there are potential applications for a wide spectrum of
purposes, including the following:
• The retraction and realignment of the anterior teeth
without the need for posterior support (anchorage)
• The closing of edentulous spaces after extraction
• The correction of the midline in patients with missing
posterior teeth
• The reestablishment of proper molar positions (i.e.,
uprighting tipped teeth) for use as abutments
• The intrusion and extrusion of teeth (e.g., to intrude
maxillary molars in an attempt to close anterior open
bites)
• The protraction and retraction of teeth
• The stabilization of teeth that have reduced alveolar bone
support
• The application of orthopedic traction to the maxilla or
mandible in the growing individual in an attempts to
alter jaw growth
Conclusions
Current problems in clinical orthodontics are no longer a
matter of which attachments or mechanical approaches to
use. Of greater importance is the basic treatment philoso­
phy related to combined clinical efforts for the achievement
of long-term dental health, enhanced facial aesthetics, and
an improved airway. The occlusion observed in each indi­
vidual is greatly influenced by baseline jaw relationships as
well as by daily masticatory and airway function. For these
reasons, the physiologic orthodontic movement of teeth has
limits and should remain within a biologic envelope. With
treatment now being rendered to children, adolescents, and
adults of all ages, a coordinated comprehensive interdisci­
plinary approach to care is more important than ever.
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129, 131, 142, 159-161, 188, 189, 199, 205, 211, 215
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171

6
Periodontal Considerations
• Teeth
• The Tissues of the Periodontium
• Aging and the Periodontium
• Etiology of Periodontal Disease
• Assessing the Individual’s Biologic and
Anatomic Risk Factors
• Potential Detrimental Effects of Orthodontic
“Camouflage” Maneuvers on the
Periodontium
• Establishing a Healthy Periodontium and
Periodontal Therapeutics
• Adult Orthodontic Treatment
• Conclusions
the saliva (e.g., antipsychotics); (5) local toxins (e.g., nico­
tine); (6) poor oral hygiene; and (7) the effects of age.
Teeth
General Information (Fig. 6-1)
Teeth are hard structures that are made up of an enamel-
covered surface called the crown and a cementum-covered
surface called the root. The root of the tooth is attached to
the alveolar bone (i.e., the jaw bone) via the periodontal
ligament (PDL). Teeth are primarily used for chewing,
speech, and swallowing. The maxillary and mandibular
arches both contain teeth. Humans have two sets of teeth
during their lifetimes: the deciduous teeth, which are also
known as the primary dentition, and the permanent teeth,
which are known as the secondary dentition. Between the
ages of 6 and 12 years, there is a mixed dentition during
which both the primary and permanent teeth are present in
the oral cavity at the same time.
There are 20 total deciduous teeth, which are composed
of two incisors, one canine, and two molars in each of the
four quadrants of the oral cavity. Under normal circum­
stances, no deciduous teeth are present at birth. Generally,
by the third year of life, all 20 deciduous teeth have erupted.
There are 32 total permanent teeth, which are composed
of two incisors, one canine, two premolars, and three molars
in each of the four quadrants of the oral cavity. Usually the
first permanent tooth to erupt into the oral cavity is the
mandibular first molar. The first molar typically erupts at
approximately 6 years of age. The molar erupts distal to the
primary dentition and behind the second primary molar.
The primary teeth eventually are replaced by the permanent
teeth. If a permanent tooth is congenitally absent, then the
primary tooth typically remains in the arch for an extended
period of time.
Degeneration of the periodontium is likely to accelerate in
the presence of specific intrinsic biologic factors (i.e., the
individual’s biotype or predisposition of the periodontium),
including the following: (1) a baseline jaw discrepancy with
malocclusion; (2) the crowding of the teeth (i.e., the dental
roots) within limited alveolar bone; (3) a forced mouth-
breathing pattern in combination with a limited ability to
close the lips together (i.e., inadequate incisor coverage)
caused by anterior skeletal vertical (height) excess; and (4)
an inadequate amount of attached gingiva at the clinical
crown interface of the teeth. When attempting to achieve a
favorable alignment of the teeth in each arch as well as
improved occlusion through ortho­dontic maneuvers, these
factors should be considered. Additional compounding
factors that may also negatively affect the periodontium
include the following: (1) active infection or inflammation
of the periodontium; (2) non-biologic restorations at the
dental–gingival interface; (3) para-occlusal habits (e.g.,
bruxism, clenching); (4) the use of medications that effect
in the Evaluation and Treatment
of Dentofacial Deformities
JEFFREY C. POSNICK, DMD, MD

172
SECTION 1  Basic Principles and Concepts
• Figure 6-1  Illustration of a sagittal view of a maxilla and mandible with the outer cortex of bone removed to demonstrate a fully erupted
deciduous (primary) dentition and the location of the developing permanent tooth buds. Also indicated on the illustration are the usual
ages of dental eruption for each tooth of both the deciduous and the permanent dentitions. From © Elsevier
Inc. All rights reserved.
Central incisor
(8–10 months)
Lateral incisor
(8–10 months)
Canine (cuspid)
(16–20 months)
1st molar
(15–21 months)
2nd molar
(20–24 months)
2nd molar
(20–24 months)
1st molar
(15–21 months)
Canine (cuspid)
(16–20 months)
Lateral incisor
(15–21 months)
Central incisor
(6–9 months)
Deciduous
(primary)
Usual age of
eruption
Permanent
(colored blue)
Usual age of
eruption
Central incisor (7th year)
Lateral incisor (8th year)
Canine (cuspid) (11th–12th year)
2nd premolar (10th year)
1st premolar (9th year)
2nd molar (12th–13th year)
1st molar (6th year)
3rd molars (17th–25th year)
1st molar (6th year)
2nd molar (12th–13th year)
2nd premolar (10th year)
1st premolar (9th year)
Canine (cuspid) (11th–12th year)
Lateral incisor (8th year)
Central incisor (7th year)
Descriptions of the Surfaces of
the Teeth (Fig. 6-2)
Labial: The surface of the anterior teeth that is closest to
the lip
Buccal: The surface of the posterior teeth that is closest to
the cheek
Facial: A synonym for labial or buccal
Lingual: Opposite the tongue in the mandibular arch and
opposite the hard palate in the maxillary arch
Mesial: Closest to the midline of the dental arch
Distal: Farthest from the midline of the dental arch
Incisal: The cutting edge of the anterior teeth
Occlusal: Used for chewing on the posterior teeth
Basic Anatomy of a Tooth (Fig. 6-3)
Crown
• Anatomic crown: The portion of the tooth that has a
surface of enamel.
• Clinical crown: The portion of the tooth that is exposed
within the oral cavity.
Root
• Anatomic root: The portion of the tooth that has a
surface of cementum.
• Clinical root: The portion of the tooth that is housed
within the maxilla or mandible and that is not exposed
to the oral cavity.
Apex of the Root
• The apex of the root is the end tip of the root, which is
also the location of a small aperture at the point of each
root. The aperture provides an entrance for the neuro­
vascular connective tissue into the pulp cavity.
Cervical Line
• The cervical line is the anatomic demarcation between
the crown and the root. It is often called the cemento-
enamel junction (CEJ).
Enamel
• The enamel is the hard, shiny surface of the anatomic
crown as well as the hardest portion of the tooth. It is

173
CHAPTER 6  Periodontal Considerations in the Evaluation and Treatment of Dentofacial Deformities
• Figure 6-2  Illustrations of the fully erupted permanent dentition in the maxilla and mandible. The palate and the lingual view illustration are used
to define terminology for the surfaces of a tooth. From © Elsevier Inc. All rights reserved.
Lower permanent teeth
Lingual surface
Buccal
surface
Distal
Mesial
Labial surface
Lingula (covering
the opening of
the mandibular
foramen)
Condyle
Coronoid
process
Buccal shelf
Mental
foramen
• Figure 6-3  Illustration of a cross-sectional view through a permanent molar and the associated alveolus.
Pertinent anatomic terminology is labeled. From © Elsevier Inc. All rights reserved.
Enamel
Dentine and dentinal tubules
Interglobular spaces
Odontoblast layer
Interproximal spaces
Dental pulp containing vessels
and nerves
Gingival (gum) epithelium (stratified)
Gingival groove
Papilla
Cement
Bone
Apical foramina
Crown
Neck
Root
Lamina propria of gingiva (gum)
(mandibular or maxillary periosteum)
Periodontium
(alveolar periosteum)
Root (central) canals
containing vessels and nerves

174
SECTION 1  Basic Principles and Concepts
changes that occur with age. The greatest modifier of the
periodontium is inflammatory disease.
The oral epithelium consists of three zones (Figs. 6-5
and 6-6):
1. Masticatory mucosa (keratinized tissue): This includes the
gingiva, the hard palate, and the dorsal surface of the
tongue. The gingiva is a fibrous investing tissue that
immediately surrounds and is contiguous with its PDL
and with the mucosal tissues of the mouth. Keratinized
epithelium also covers the hard palate.
• Attached gingiva: This is the portion of the gingiva
that is firm, dense, stippled, and tightly bound to the
underlying periosteum, tooth, and bone.
• Free gingiva: This part of the gingiva surrounds the
tooth and is not directly attached to the tooth surface.
made of small hexagonal rods called enamel prisms that
are parallel to one another.
• Enamel is 96% inorganic minerals by weight and 4%
organic matter and water by weight.
Cementum
• The cementum is a thin, dull layer on the surface of the
anatomic root. The cementum is similar in structure and
chemical composition to bone. With age, cementum
increases in thickness.
• Cementum is 45% to 50% inorganic material by
weight and 50% to 55% organic matter and water
by weight.
Dentin
• The dentin is the hard tissue that underlies both the
enamel and the cementum and that constitutes the major
portion of the tooth. Dentin is a modification of osseous
tissue. It is composed of a number of dental tubules
(small, wavy, and branching tubes) that are located in a
dense matrix.
• Dentin is 70% inorganic material by weight, 20%
organic material, and 10% water.
Cusp
• A cusp is an elevation on the occlusal surface of the
molars and the premolars that makes up a divisional part
of the tooth. The incisal edge of the canines is referred
to as the cusp, and it is used for prehension (i.e., the
grasping and tearing) of food.
Pulp Cavity
• The pulp cavity contains the dental pulp (neurovascular
connective tissue). The pulp is separated into the pulp
chamber, which is located in the coronal portion of the
tooth, and the pulp canal, which is located in the root
portion of the tooth.
Cingulum
• The cingulum is a convex elevation that is located on the
lingual surface of the crowns of anterior teeth just incisal
to the CEJ.
The Tissues of the Periodontium
The periodontium includes the investing and supporting
tissues of the teeth. It consists of two parts: the attachment
apparatus (the cementum, the alveolar bone, and the inter­
vening PDL) and the dentogingival unit (the gingival con­
nective tissue that inserts into the supracrestal cementum
and the sulcular and junctional epithelium as well as the
latter’s attachment to enamel) (Fig. 6-4). The cementum
covers the root surfaces. It serves as the attachment for the
fibers of the PDL to the tooth as does the (cortical) alveolar
bone of the alveolar socket. The periodontium is affected
by the individual’s unique maxillofacial skeletal anatomy, by
functional (occlusal) forces, and by degenerative cellular
• Figure 6-4  Intraoral view demonstrating the normal width of
attached gingiva in the human permanent dentition. From Newman
MG, Takei HH, Klokkevold PR, Carranza FA: Carranza’s clinical
periodontology, ed 11, St. Louis, 2012, W.B. Saunders Company,
Figure 2-3.
• Figure 6-5  Diagram showing the anatomic landmarks of the gingiva.
From Newman MG, Takei HH, Klokkevold PR, Carranza FA: Carranza’s
clinical periodontology, ed 11, St. Louis, 2012, W.B. Saunders
Company, Figure 2-2.
Alveolar mucosa
Mucogingival junction
Marginal groove
Attached gingiva
Free or marginal gingiva
Gingival sulcus

175
CHAPTER 6  Periodontal Considerations in the Evaluation and Treatment of Dentofacial Deformities
tissue is called the biologic width. In general, an individual
can only maintain health when the sulcus depth is no more
than 3 to 4 mm. Greater depth provides a safe haven for
bacteria that cannot be easily removed through normal oral
hygiene maneuvers. A lower-than-average alveolar crest level
is acceptable as long as it is stable (i.e., not progressive) and
the periodontium is free of active disease. On the palatal
surface of the teeth, the attached gingiva blends with the
equally firm and highly keratinized palatal (masticatory)
mucosa. The interdental gingiva occupies the gingival embra­
sure (i.e., the interproximal space beneath the area of tooth
contact). It consists of the facial papilla, the lingual papilla,
and the valley-like depression that connects the two in the
interproximal contact area, which is called the col. In the
absence of proximal tooth contact, the gingiva is firmly
bound over the interdental bone; it forms a smooth, round
surface without a triangular interdental papilla. The connec­
tive tissue of the gingiva is densely collagenous, and it
contains collagen fiber bundles called gingival fibers (Fig.
6-7). When these fiber bundles insert into the tooth’s
cementum, they are called Sharpey’s fibers, and they result in
the mechanical attachment of the sulcular and supracrestal
(i.e., crestal to the alveolar process) gingiva. These fibers are
able to withstand masticatory forces without deflection or
detachment from the tooth surface. The connective tissue
attachments extend from just apical to the junctional
• Marginal gingiva: This is most coronal portion of the
gingiva. This term is often used to refer to the free
gingiva that forms the wall of the gingival crevice in
a normal, healthy mouth.
• Crevicular (sulcular) epithelium: This is the non-
keratinized epithelium of the gingival crevice.
• Junctional epithelium: This involves a single layer or
multiple layers of non-keratinized cells that adhere to
the tooth surface at the base of the gingival crevice.
This was formerly called the epithelial attachment.
2. Lining mucosa (non-keratinized tissue): This epithelium
makes up the majority of the mucosa of the mouth and
is the primary lining of the oral mucosa.
3. Specialized mucosa: This is found specifically in the
regions of the taste buds on the dorsum of the tongue.
The gingiva is the part of the oral mucous membrane
that covers the occlusal aspect of the alveolar processes of
the jaws and that surrounds the necks of the teeth. The
junctional epithelium and the connective tissue attachment
have a characteristic dimension of 2 to 4 mm; this zone of
• Figure 6-6  Histologic appearance of healthy gingiva. A photomicro­
graph of a demineralized tooth with the gingival tissues in situ (hema­
toxylin and eosin stain, low magnification). The amelocemental junction
(A) and the enamel space (ES) are shown. Gingival health is character­
ized by the organization of the epithelium into distinct zones: the
junctional epithelium (A to B), the sulcular epithelium (B to C), the free
gingiva (C to D), and the attached gingiva (D to E). The gingival con­
nective tissue is composed of densely packed, organized, and interlac­
ing collagen bundles. There are a few scattered inflammatory cells, but
there is no significant inflammatory cell infiltrate. From Newman MG,
Takei HH, Klokkevold PR, Carranza FA: Carranza’s clinical periodontol­
ogy, ed 11, St. Louis, 2012, W.B. Saunders Company, Figure 21-1.
A
B
ES
C
D
E
• Figure 6-7  Diagram of the gingival dental fibers that extend from
the cementum (1) to the crest of the gingiva, (2) to the outer surface,
and (3) external to the periosteum of the labial plate. Circular fibers (4)
are shown in cross-section. From Newman MG, Takei HH, Klokkevold
PR, Carranza FA: Carranza’s clinical periodontology, ed 11, St. Louis,
2012, W.B. Saunders Company, Figure 2-20.
1
4
2
3

176
SECTION 1  Basic Principles and Concepts
called Sharpey’s fibers. Cellular elements of the PDL include
fibroblasts, endothelial cells, cementoblasts, osteoblasts,
osteoclasts, tissue macrophages, and stratified epithelial
cells. The PDL has physical, formative, nutritional, and
sensory functions. These include the physical functions of
the transmission of occlusal forces to the bone, the attach­
ment of the teeth to the bone, the maintenance of the
gingival tissues in relationship to the teeth, the resistance to
the impact of occlusal forces, and the protection of the
vessels and nerves from injury by mechanical forces.
Destruction of the PDL and the alveolar bone by disease or
injury disrupts the balance between the periodontium and
the occlusal forces. The PDL supplies nutrients to the
cementum, the bone, and the gingiva through the blood
vessels; it also provides lymphatic drainage to the same
structures. The innervation of the PDL provides proprio­
ception and tactile sensitivity. The PDL includes trans­
septal, alveolar–crestal, oblique, and apical oriented fibers.
Cementum
Cementum is the calcified mesenchymal tissue that forms
the outer covering of the tooth root. There are two types of
cementum: acellular and cellular. Both consist of a calcified
interfibrillar matrix and collagen fibrils. The cellular type
contains cementocytes in individual spaces (lacunae) that
allow for communication with each other through a system
of canaliculi. There are two types of collagen fibers. The first
type is Sharpey’s fibers, which are the principal fibers of the
PDL and which are formed by fibroblasts. The second
group of fibers is thought to be produced by the cemento­
blasts and to form an interfibrillar substance. The distribu­
tion of acellular and cellular cementum varies. The coronal
half of the root is usually covered by the acellular type of
cementum, whereas the cellular cementum is more common
in the apical half of the root. The inorganic content of
cementum includes hydroxyapatite, a carbohydrate–protein
complex, and acid mucopolysaccharides.
The relationship of the interface between the cementum
and the enamel at the crown–root interface varies. Cemen­
tum overlaps the enamel in about two thirds of cases. In the
other third, there is an edge-to-edge arrangement in which
a small percentage of the cementum and the enamel fail
to meet.
When cementum resorption occurs, it is seen micro­
scopically as concavities on the root surface. Multinucleated
giant cells and large mononuclear macrophages are gener­
ally found adjacent to the cementum that is undergoing
active resorption. The resorptive process may extend into
the underlying dentin and even into the pulp. In a physi­
ologic setting, embedded fibers of the PDL reestablish a
functional relationship in the new cementum. Cementum
repair requires the presence of viable connective tissue. If
epithelium proliferates into an area of cementum, then
resorption rather than repair will likely take place. Fusion
of the cementum and the alveolar bone with obliteration of
epithelium of the sulcular (crevicular) gingiva to the supra­
crestal cementum of the root.
The junctional epithelium is connected to the tooth
surface via a hemidesmosomal adhesion. These two ectoder­
mal tissues and their interface act to block the flow of
toxic chemicals and organisms from the oral cavity into
the body.
The gingival sulcus contains a fluid that is derived from
the gingival connective tissue and that flows through the
thin epithelium of the sulcular wall. The gingival fluid is
cleansing, and it contains sticky plasma proteins to increase
the adhesion of the epithelial attachment to the tooth. The
fluid possesses antimicrobial properties, and it is active in
its defense of the gingiva. It may also serve as a medium for
bacterial growth, which contributes to the formation of
dental plaque and calculus. The amount of gingival fluid
(exudate) increases with inflammation. The composition of
gingival fluid has many similarities to that of blood serum.
The attached gingiva is continuous with the marginal
gingiva, and it consists of stratified squamous epithelium
and an underlying connective tissue stroma. The superficial
layer is keratinized, parakeratinized, or both. The connec­
tive tissue of the gingiva is known as the lamina propria. It
is densely collagenous, with few elastic fibers, and it consists
of two layers: a papillary layer next to the epithelium and a
reticular layer next to the periosteum of the alveolar process.
Each interdental papilla consists of a central core of
densely collagenous connective tissue covered by stratified
squamous epithelium. The facial and lingual papillae are
joined with the connective tissue of the col and the stratified
squamous epithelium from the adjacent interdental papil­
lae. The epithelium of the col is not keratinized and there­
fore more susceptible to inflammation. The shape of the
interdental gingival papillae correlates with the shape of the
teeth and the embrasures. The interdental papillae may be
broad or narrow, depending on dental positioning and
points of connection.
In a normal physiologic state, the gingiva is firm and
resilient. With the exception of the movable free margins
(i.e., the marginal gingiva), it is tightly bound to the under­
lying bone. This is the result of the collagenous nature of
the lamina propria and its integration with the periosteum
of the alveolar process. The visual stippling that is seen when
viewing the gingival surface represents the pulling of the
superficial gingival layer by the tight connective tissue
attachments to the underlying alveolar process.
The Periodontal Ligament
The PDL is the connective tissue structure that surrounds
the root and that connects the root with the bone in the
tooth socket. It is continuous with the connective tissue of
the gingiva, and it communicates with the bone through
vascular channels. The principal fibers of the PDL are col­
lagenous organized bundles that insert into the cementum
on one side and into the bone on the other side; they are

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CHAPTER 6  Periodontal Considerations in the Evaluation and Treatment of Dentofacial Deformities
The alveolar bone is perforated by numerous channels that
contain blood vessels, lymph vessels, and nerves, which link
the PDL with the cancellous portion of the alveolar bone.
The vascular supply of the bone is derived from blood
vessels in the PDL and in the marrow spaces and from small
branches of peripheral vessels that penetrate the cortical
plates. The interdental septum consists of cancellous bone
that is bordered by the socket walls of approximating teeth
and the facial and lingual cortical plates.
The mesiodistal angulation of the crest of the interdental
septum parallels a line drawn between the CEJs of the
approximating teeth. The average distance between the crest
of the alveolar bone and the CEJ in the mandibular anterior
region in an individual who is periodontally healthy is
approximately 1 mm. With disease progression, the dis­
tance between the bone ridge and the CEJ increases
throughout the mouth.
The alveolar bone contour normally conforms to the
prominence of the roots of the teeth, with regions of mild
depression in between. The height and thickness of the
facial and lingual bony plates are affected by the alignment
of the teeth and the angulation of the roots in the bone.
For example, in the patient with mandibular deficiency and
excessive incisor procumbency, the labial bone may be thin,
and apical migration may be seen along the tooth surface.
When the mandibular incisor teeth are lingually positioned
(i.e., skeletal Class III), the facial bony plate is generally
thicker than normal. Another example is seen when the
maxillary molar roots are at acute angles to the palatal bone.
The effects of the root location and angulation result in
recession of the marginal bone.
An isolated area in which a tooth root is denuded of
labial cortical bone, the root surface is covered only by
periosteum and overlying gingiva, and the marginal bone
remains intact is termed fenestration. An area of the tooth
root in which there is denuded bone and where the root
surface is covered only by periosteum where the root denu­
dation extends to the margin is called dehiscence. Dehis­
cences are more common on the labial surface of the lower
anterior teeth and on the molars and premolars of the
maxilla. Congenital or developmental jaw hypoplasia with
dental crowding and trauma from occlusal treatments or
orthodontics are common etiologic factors for fenestrations
and dehiscences.
Alveolar bone is a structure that is constantly in a state
of flux. It is maintained by a delicate balance between bone
formation and bone resorption, and it is controlled by local
and systemic influences. Bone is resorbed in areas of pres­
sure and deposited in areas of tension. With age and normal
occlusal forces, there is a tendency for the mesial migration
of the teeth. As a result, the associated alveolar bone is
remodeled via resorption and deposition.
The purpose of the alveolar process is to support the
teeth both while they are at rest and while they are function­
ing. Its structure is dependent on the stimulation that it
receives from masticatory function, because it undergoes
the PDL is termed ankylosis. When ankylosis does occur, it
generally happens after chronic periapical inflammation,
tooth replantation, or significant occlusal trauma. It may
also represent a congenital failure of eruption.
The anatomic root is the portion of the tooth that is
normally covered by cementum. The anatomic crown is the
portion of the tooth that is covered by enamel. The clinical
crown is the part of the tooth that includes the anatomic
part of the crown and the part of the root that has been
denuded of periodontium and that is visible in the oral
cavity. The clinical root is that portion of the tooth that
remains covered by periodontal tissues (i.e., the PDL, the
cementum, and the gingiva). Exposure of the root via the
apical migration of the gingiva margin is called gingival
recession. Exposure of the root to the oral cavity via the
apical migration of the junctional epithelium without apical
migration of the gingival margin results in pocketing. In
either case, periodontal degenerative changes result in the
permanent exposure of connective tissue (i.e., the dentin
and the cementum) to the external environment.
The Alveolar Bone
All parts of the alveolar process serve to support the teeth.
Occlusal forces are transmitted through the PDL to the
inner wall of the alveolus, which is then supported by the
cancellous trabeculae. The cancellous trabeculae in turn are
buttressed by the labial and lingual cortical plates. The
alveolar process is the bone that supports the tooth socket,
and it consists of the following:
• The inner socket wall of thin compact bone (the alveolar
bone proper);
• The supporting alveolar medullary bone (the cancellous
trabeculae); and
• The facial and lingual plates (compact bone).
The alveolar process consists of calcified matrix with
osteocytes that are enclosed within spaces called lacunae.
The canaliculi form an anastomosing system through
the intercellular matrix of the bone, which brings oxygen
and nutrients to the osteocytes and which removes meta­
bolic waste products. In the cancellous trabeculae, the
matrix is arranged in lamellae that are demarcated from
each other by prominent cement linings. The compact alveo­
lar bone (i.e., the bony lining of the alveolus) consists of
closely arranged lamellae and Haversian systems. The prin­
cipal fibers of the PDL that anchor the tooth in the socket
are embedded into the alveolar bone and are referred to as
Sharpey’s fibers. The socket wall consists of dense laminated
bone. The cancellous portion of the alveolar bone consists
of trabeculae, which enclose irregularly shaped marrow
spaces that are lined with a layer of thin, flattened
ostial cells.
The bony wall of the tooth socket appears radiographi­
cally as a thin radiopaque line; it is called the lamina dura.

178
SECTION 1  Basic Principles and Concepts
Etiology of Periodontal Disease
Gingivitis and Periodontitis
Inflammation of the gingiva, which is also known as gingi­
vitis, is the most common form of gingival disease (Figs. 6-8
through 6-12).1,19,177,183,216 This occurs as a result of local
irritants, such as the toxins released by the microorganisms
related to dental plaque and calculus. Foreign bodies (e.g.,
orthodontic appliances, irregular dental restorations) may
also serve as local irritants as well as plaque traps. The
constant remodeling in response to occlusal forces. When
force is applied to a tooth, that force is displaced against the
resilient PDL, thereby creating areas of tension and com­
pression. The facial and lingual walls of the tooth socket
bend in the direction of the force. When the force is released,
the tooth, the PDL, and the bone spring back toward their
original positions. In response to these forces, osteoblasts
and newly formed osteoid will line the socket in areas of
tension, whereas osteoclasts position themselves and resorp­
tion occurs in areas of pressure. The bone trabeculae are
aligned in the path of the tension and compressive stresses
to provide maximum resistance to the occlusal force with
the minimum of bone substance. Forces that exceed the
adaptive capacity of the bone produce injury. When occlu­
sal forces are increased, the cancellous trabeculae also
increase in number and thickness to provide necessary
support.
Aging and the Periodontium
The prevalence of periodontal disease with tissue destruc­
tion and the loss of teeth and tooth structure tends to
increase with age.106,155,160,171 Another consequence of age is
reduced tissue elasticity through the degeneration of the
elastic fibers. Hormonal changes also occur, and these
change the local tissue environment. Traditional thinking is
that the degenerative gingival changes associated with aging
may include recession, diminished keratinization, reduced
stippling, decreased connective tissue cellularity, increased
intercellular substances, and reduced oxygen consumption.
In the PDL, degenerative aging effects are thought to
include a decrease in elastic fibers and a decrease in vascular­
ity and mitotic activity. If these effects occur, the ability of
the alveolar bone to withstand occlusal forces is diminished.
Frequent changes in tooth structure with age are seen,
including occlusal wear with a loss of enamel substance that
reduces cusp height and inclination. The degree of attrition
is influenced by the masticatory musculature, the consis­
tency of the food eaten, and occlusal factors and habits such
as clenching and bruxism. A degree of continued tooth
eruption usually occurs as teeth wear. As a result, the clinical
crown may become longer, which creates further leverage
on the bone with masticatory forces. An opposing factor is
the fact that the clinical crowns are simultaneously reduced
through attrition, often with an equilibrium or balance
being present between the teeth and their bony support.
The wear of the teeth along the proximal surfaces may also
occur, which results in mesial migration. On average, proxi­
mal wear reduces the anteroposterior length of the dental
arch by approximately 5 mm by the age of 40 years and by
twice that by life’s end. When chronic periodontal disease
is added to physiologic degenerative aging, the destructive
response of the periodontium is exacerbated. There may be
continued gingival recession, attrition, and the reduction of
alveolar bone height as a result of a combination of these
factors.31
• Figure 6-8  Photograph of the maxillary anterior dentoalveolar
region. Dehiscence of the labial cortical plate of the canine and fenes­
tration of the labial cortical plate of the first premolar are demonstrated.
From Newman MG, Takei HH, Klokkevold PR, Carranza FA: Carranza’s
clinical periodontology, ed 11, St. Louis, 2012, W.B. Saunders
Company, Figure 2-60.
• Figure 6-9  Illustration of pocket formation that indicates expansion
in two directions (arrows) from the normal gingival sulcus (left) to the
periodontal pocket (right). From Newman MG, Takei HH, Klokkevold
PR, Carranza FA: Carranza’s clinical periodontology, ed 11, St. Louis,
2012, W.B. Saunders Company, Figure 13-1.

179
CHAPTER 6  Periodontal Considerations in the Evaluation and Treatment of Dentofacial Deformities
• Figure 6-10  Different types of periodontal pockets. With a gingival
pocket (A), there is no destruction of the supporting periodontal
tissues. With a suprabony pocket (B), the base of the pocket is coronal
to the level of the underlying bone, and bone loss is horizontal. With
an intrabony pocket (C), the base of the pocket is apical to the level
of the adjacent bone, and bone loss is vertical. From Newman MG,
Takei HH, Klokkevold PR, Carranza FA: Carranza’s clinical periodontol­
ogy, ed 11, St. Louis, 2012, W.B. Saunders Company, Figure 13-2.
A
B
C
• Figure 6-11  Classification of pockets according to involved tooth
surfaces. A, Simple pocket. B, Compound pocket. C, Complex
pocket. From Newman MG, Takei HH, Klokkevold PR, Carranza FA:
Carranza’s clinical periodontology, ed 11, St. Louis, 2012, W.B. Saun­
ders Company, Figure 13-3.
A
B
C
• Figure 6-12  Probing of a deep periodontal pocket. The entire length
of the periodontal probe has been inserted into the base of a pocket
in the palatal surface of the first premolar. From Newman MG, Takei
HH, Klokkevold PR, Carranza FA: Carranza’s clinical periodontology,
ed 11, St. Louis, 2012, W.B. Saunders Company, Figure 13-4.
the epithelial junction may separate from the root, and the
pocket will migrate downward. The epithelium of the lateral
wall of the pocket proliferates with inflammatory tissue,
which results in varying degrees of degeneration and necro­
sis. Intrabony periodontal pockets are said to be present
when the base is apical to the level of the alveolar bone. The
extension of inflammation from the margin of the gingiva
into the supporting periodontal tissues marks the transition
from gingivitis to periodontitis.6,40,41,107,117,175,200 The essen­
tial problem of periodontal disease is the destruction of
alveolar bone with a loss of crestal height and PDL destruc­
tion. If periodontal disease is left untreated, it will lead to
the loosening and loss of the teeth.
Trauma from Occlusion
Occlusal forces affect the condition and structure of the
periodontium.53,54,59,104,129,134,160,181,191,204 To remain structur­
ally and metabolically sound, the PDLs and the alveolar
bone require the mechanical stimulation of occlusal forces.
When occlusal forces exceed the adaptive capacity of the
tissue, injury occurs. The injury that occurs to the periodon­
tium is called trauma from occlusion, and it can be classified
as either primary or secondary occlusal trauma. Primary
occlusal trauma occurs when greater-than-normal occlusal
forces are placed on teeth with a normal periodontal attach­
ment apparatus (i.e., those that are periodontally stable).
Secondary occlusal trauma occurs when normal occlusal
forces are placed on teeth with compromised periodontal
attachment (i.e., those with periodontal disease).
The periodontium attempts to accommodate the func­
tional demands that are placed on it by the masticatory
system. The adaptive capacity of the periodontium varies
from person to person. The periodontium is influenced by
the severity, direction, frequency, and duration of the force
that is put on it and the patient’s specific anatomy. The
principal fibers of the PDL are arranged so that they can
best accommodate occlusal forces in the long axis of the
inflammation caused by local irritants can result in ulcer­
ative, necrotic, and proliferative changes in the gingival
tissues.29,30,34,99,165,170,221 When there is deepening of the gin­
gival sulcus, there can be injury to the supporting periodon­
tal tissues; this may become an irreversible process. With
continued inflammation, hyperplastic changes of the gingiva
occur, and the crest of the gingival margin extends toward
the crown. Inflammation causes a proliferation of and a
change in the quality of the sulcus and the junctional epi­
thelium such that their normal protective nature becomes
dysfunctional. The sulcus becomes a pocket; ulceration
through the epithelial barrier with exposure of the underly­
ing connective tissue to the oral cavity is a frequent occur­
rence. The organisms and their toxins are then able to access
the exposed connective tissue, which undergoes further
pathologic changes.93,133,135,154,193 As the process continues,

180
SECTION 1  Basic Principles and Concepts
tooth. Forces that are not aligned well with the tooth’s load-
bearing capacity place increased compression on specific
locations of the PDL. This may result in resorption of bone,
depending on the extent and duration of the occlusal force.
If the trauma is excessive, a destructive change in the peri­
odontium will occur. If the injurious force is relieved rapidly
enough, repair rather than destruction will occur. When
trauma is combined with active infection, rapid irreversible
destruction of the periodontium is more likely. The degree
to which these factors interact and cause destruction remains
controversial. There is a need for ongoing clinical research
to clarify these issues.
Traditional thinking is that trauma from occlusion is
caused by alterations in the occlusal forces, the reduced
capacity of the periodontium to withstand what would
otherwise be considered normal, or both. Malocclusion is a
risk factor for occlusal trauma, but damage may also occur
in the presence of a “normal” occlusion. Trauma from occlu­
sion refers to the tissue injury rather than the specific occlu­
sion. Increased masticatory forces are not traumatic if the
periodontium can accommodate them. Trauma from occlu­
sion and inflammation from an infectious or foreign-body
process are different pathologic processes that can occur
either in isolation or together. Inflammation typically starts
in the gingiva and then spreads into the supporting peri­
odontal tissues. Trauma from occlusion causes pathologic
change of the attachment apparatus. When this occurs in
the presence of inflammatory processes, these two patho­
genic factors may act synergistically to cause greater damage
to the periodontium than the sum of each factor’s singular
effect. These combined components are called co-destructive
factors.
The histopathologic lesion of occlusal trauma is called
the lesion of the attachment apparatus, and it is characterized
by the following:
• Hyaline degeneration of the PDL
• Vascular thrombosis in the PDL
• Necrosis in the PDL
• Frontal and rear “undermining” resorption of the alveo­
lar bone
• Cementum resorption
The lesion of the attachment apparatus can occur and
progress rapidly. It is believed that, when the lesion interacts
with plaque-induced inflammatory responses, then the loss
of the periodontium is likely to be accelerated.
Effects of Orthodontic Appliances and Tooth
Movement Forces
Tooth movement during orthodontic therapy is the result
of controlled forces placed on the teeth and then transmit­
ted to the PDL. Strong or heavy forces (i.e., forces that far
exceed capillary blood pressure) result in the crushing of the
PDL on the compression side of the tooth, with local isch­
emia and degeneration (i.e., hyalinization). Moderate forces
that exceed capillary blood pressure result in the compres­
sion of the PDL with a delay in bone resorption and the
movement of the tooth.89 Light continuous forces that are
less than the capillary blood pressure result in only limited
ischemia to the PDL, with gradual bone resorption on the
compression side.174 The patient’s age is not a contraindica­
tion to orthodontic treatment per se. Interestingly, in the
adult, the hyalinized (necrotic) zones are formed more
readily on the pressure side of the orthodontically moving
tooth; this will temporarily slow tooth movement.62 The
hyalinized zone is soon eliminated with the reorganization
of the tissues, first through the resorption of the marrow
spaces (thus undermining resorption) and then through the
repair of the PDL and finally of the alveolar bone.172 The
anticipated regeneration of the PDL on the compression
side and the formation of new bone on the tension side will
likely be hampered by the presence of active inflammation
in the periodontal tissues (i.e., periodontitis).169 This patho­
logic response is dependent on how long the PDL remains
compromised. This is the reason why inflammation should
be controlled through effective periodontal treatment before
orthodontic tooth movement.*
Until the mid 1980s, heavy intermittent orthodontic
forces were routinely used, and this required patient visits
every 3 to 4 weeks.176 This allowed the hyalinized fibers to
recover before another heavy orthodontic force was applied.
Contemporary orthodontics involves the use of light, con­
tinuous force. This moves the teeth with less discomfort and
more rapidly, and it also allows visits to be spaced at longer
intervals.
In a patient with a periodontally compromised dentition
and with a baseline loss of alveolar bone, the center of
resistance of the involved teeth moves apically.141,157 The net
effect is that the involved teeth are more prone to tipping
rather than to bodily movement when orthodontic forces
are applied. To achieve improvement in the periodontium,
orthodontic treatment requires a combination of light con­
trolled forces as well as the movement of teeth more com­
pletely into the alveolar housing. In the presence of active
disease, orthodontic therapy should be postponed until
effective periodontal treatment is accomplished. This
approach to orthodontic tooth movement has been shown
to improve any preexisting compromised periodontium.
Interestingly, the orthodontic movement of endodonti­
cally treated teeth is not a risk factor to the periodontium,
because the response of the PDL is not affected by the
pulp. Some studies do indicate that endodontically treated
teeth are slightly more prone to root resorption during
orthodontic treatment as compared with teeth with
normal vitality.
Teeth that are already tipped outside of the cortical plate
(e.g., proclined mandibular incisors in the individual
with Class II malocclusion) and that are orthodontically
*References 20, 21, 24, 25, 36, 43, 47, 49, 56, 66, 100, 111, 115, 116,
121, 122, 142, 144, 151, 156, 173, 182, 192, 197, 198, 202, 218-220

181
CHAPTER 6  Periodontal Considerations in the Evaluation and Treatment of Dentofacial Deformities
uprighted into sound alveolar housing are likely to improve
in overall periodontal health, even when the gingiva levels
remain borderline. Animal studies indicate that, without
the presence of plaque, orthodontic forces on the teeth do
not in themselves induce gingivitis.67 In the presence of
plaque, however, similar forces can cause angular bone
defects and, with tipping or torquing movements, gingival
attachment loss (i.e., recession) can occur.68-70 Clinical
studies have demonstrated that, with adequate plaque
control, even teeth with longstanding reduced periodontal
support can undergo successful tooth movement without
further compromise.63 In patients with no active periodon­
tal disease and with good oral hygiene—and even in adults
with reduced but healthy residual periodontium—
physiologic orthodontic treatment causes no significant
detrimental long-term effects on the periodontal attach­
ment, including the bone levels. Physiologic tooth move­
ment involves light forces and the movement of teeth into
(not outside of) alveolar bone.37-39
In a cross-sectional study, radiographic crestal bone levels
in adults (N = 104) who completed orthodontic treatment
at least 10 years previously were shown to be no different
than those of matched control subjects (N = 76).161 In a
2-year post orthodontic study, Trosello and colleagues com­
pared adult women who had multi-banded orthodontic
therapy (N = 30) with age-matched (non-orthodontically
treated) controls (N = 30).203 It was found that the orthodon­
tically treated patients had a higher prevalence of root
resorption (17% versus 2%), although there was a lower
prevalence of mucogingival defects (5% versus 12%). The
root resorption differences were most common in the maxil­
lary incisors, followed by the mandibular incisors. It appears
that, in adults, when biologically sound orthodontic maneu­
vers are carried out, minimal detrimental effects on the
health of the periodontium occur. In the short term, gingi­
vitis and gingival hyperplasia may occur, but there is no
attachment loss or irreversible effects. In the long term,
when the teeth are moved into (not out of) the alveolar
bone, mild root resorption (i.e., 1.0 to 1.5 mm) may be
documented, but attachment loss (i.e., irreversible change)
only occurs in areas of active periodontitis.
It is known that plaque is the primary etiologic factor of
gingivitis. A patient’s inability to clean adequately around
orthodontic devices (e.g., banded teeth, brackets, wires,
springs, coils, elastics, plates) will promote plaque accumu­
lation, which can lead to gingival inflammation. Before the
extensive use of bonded brackets, overgrowth of anaerobes
in the patient’s sulcus was typical.57 Fortunately, the common
practice of placing numerous subgingival orthodontic bands
in each quadrant has gone by the wayside. Nevertheless, a
shift in the subgingival microflora to a more pathogenic
population that is similar to what is seen in periodontal
disease sites may occur with use of orthodontic devices.131
Even without banded bracket appliances, an active and dili­
gent oral hygiene program for the patient that includes
frequent periodic checkups by an appropriate dentist is
required throughout orthodontic treatment.
Dental Restorations: Gingival Interface
The relationship between bacterial plaque accumulation
and gingival inflammation has been documented since at
least the 1960s.132 A patient’s susceptibility to gingival
inflammation is not based solely on the mere quantity of
dental plaque but also on the virulence of the resident
plaque microorganisms. The bacterial composition of dental
plaque is dynamic, and the pathogenicity of each specific
organism is subject to change over time. It is a dental
dictum that creating a confluent restorative–gingival inter­
face is an important factor that allows patients’ oral hygiene
efforts to reduce the accumulation of plaque and microor­
ganisms and to decrease—if not eliminate—the resulting
gingivitis. For this reason, emphasis should be placed on the
marginal integrity of dental restorations; the coronal contour
of the restoration; the embrasure and contact; and the mar­
ginal location of the restoration. The proper marginal loca­
tion of a restoration relative to the alveolar bone is thought
to be one of the most important parameters for achieving
and maintaining long-term gingival health.92,124-126,139 Simi­
larly, all patients who are undergoing dental therapy should
be philosophically taught and technically trained to perform
effective plaque-removal practices.
Assessing the Individual’s Biologic
and Anatomic Risk Factors
Destruction of the periodontium is more likely to occur in
the presence of known risk factors. Specific risk factors
include 1) infection, 2) primary occlusal trauma, 3) iatro­
genic causes, and 4) intrinsic biologic anatomic aspects. The
known intrinsic (unique to the individual) biologic ana­
tomic risk factors for periodontal disease may be referred to
as the individual’s biotype (Figs. 6-13 through 6-29). These
factors include the following:
• Inadequate attached gingiva surrounding the clinical
crowns of the teeth
• Inadequate alveolar bone to house the roots of the full
complement of teeth in each arch
• Inadequate nasal airflow with a forced mouth-breathing
pattern, often in association with vertical (skeletal) excess
and inadequate lip closure, with limited coverage of the
incisors and the gingiva
• The effects of malocclusion associated with a jaw
deformity
The individual’s biotype may pose risk factors for peri­
odontal tissue loss. These risk factors can often be overcome
or at least managed through surgical, orthodontic, and
dental interventions; meticulous home care; and the avoid­
ance of toxins such as tobacco, certain medications, and
certain chemicals.
Text continued on p. 200

182
SECTION 1  Basic Principles and Concepts
• Figure 6-13  A 50-year-old man was referred by his general dentist to an orthodontist, who then referred the patient for surgical evaluation. The
patient had a history of juvenile rheumatoid arthritis with temporomandibular joint involvement. There is condylar erosion with loss of posterior facial
height with retrusion and clockwise rotation of the mandible, which resulted in a Class II anterior open-bite malocclusion. Adequate painless vertical
mouth opening is present, and no symptomatic temporomandibular disorder is present. Over the years, there has been destruction of the dentition
and the periodontal apparatus with a degree of labial bone loss and gingival recession. At referral to this surgeon, the patient had a history that
documented heavy snoring, restless sleeping, and daytime somnolence. An attended polysomnogram confirmed a respiratory disturbance index
of 10 events per hour. There is intranasal obstruction as a result of septal deviation and inferior turbinate enlargement, a retropositioned palate as
a result of maxillary retrusion, and a retropositioned tongue as a result of mandibular retrusion. The soft palate and the tongue are normal with
regard to function and size. The patient had previously undergone tonsillectomy. His biologic and anatomic risk factors for periodontal disease
include inadequate alveolar bone (i.e., an inadequate alveolar bone/dental root ratio); nasal obstruction and mouth breathing with lip incompetence;
and malocclusion with secondary trauma. A comprehensive approach was recommended to address the patient’s upper airway and breathing
difficulties, his occlusion issues and his long-term dental health, and his facial aesthetics. A, Frontal facial and occlusal views before treatment.
B, Profile facial view and lateral cephalometric radiograph before treatment. C, Panorex radiograph before treatment.
Or
Or
Or
Or
Or
Or
O thththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatathicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C.
C Pos
os
os
os
os
os
os
os
os
os
os
os
os
os
os
os
osnicicicicicicicicicicicici k
A
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orththththththththtr ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatata hicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry; J.C.
C.
C.
C.
C.
C.
C.
C Pos
os
osnicick
B
C
R
L

183
CHAPTER 6  Periodontal Considerations in the Evaluation and Treatment of Dentofacial Deformities
Or
Or
Or
Or
Orthththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatatatatatata hicic Su
Surg
r ery
ry
ry
ry; J.C.
C.
C.
C Pos
os
os
os
os
os
os
os
os
os
os
os
os
os
os
os
o nicicicick
A
• Figure 6-14  A 26-year-old college graduate arrived for surgical evaluation. Since the mixed dentition, he was recognized to
have a developmental jaw deformity that was characterized by maxillary deficiency in combination with relative mandibular excess.
Camouflage orthodontic treatment including four bicuspid extractions was carried out when he was between 12 and 16 years
old. A residual Class III negative overjet with an anterior open-bite malocclusion remains. The patient had never been able to
breathe well through his nose as a result of septal deviation and inferior turbinate enlargement. Secondary occlusal trauma resulted
in the need for root canal therapy and crowns in all four posterior quadrants. There is labial bone loss and gingival recession. A
comprehensive dental rehabilitative and reconstructive approach will require periodontal evaluation and treatment followed by
orthodontic (dental) decompensation and then jaw and intranasal surgery. A, Frontal facial and occlusal views before treatment.
B, Profile facial view and lateral cephalometric radiograph before treatment. C, Panorex radiograph before treatment.
C
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orththththththththththththththththtr ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gnatatatatatatatatatatatatathicicicicicicicicicicicicici Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C Pos
os
os
os
o nicicick
B

Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
A
B
• Figure 6-15  A 16-year-old boy was born with Stickler syndrome, which is a type II collagen mutation. At the time of his birth, the Pierre-Robin
sequence was appreciated. The patient underwent repair of the cleft palate before he was 1 year old. He had positive eye findings and required
the treatment of a retinal detachment during his teenage years; a small cataract is being followed. He arrived for the evaluation of a jaw deformity
and malocclusion, which were characterized by maxillomandibular deficiency with anterior open-bite malocclusion. This was combined with chronic
obstructive nasal breathing and a long face growth pattern. Attempted growth modification and camouflage orthodontics earlier in life were inef­
fective. There was generalized root deficiency throughout the maxillary and mandibular dentition, likely as a result of the collagenopathy. The patient
agreed to an orthodontic and surgical approach. Further orthodontic (dental) decompensation was cautiously carried out as a result of the com­
promised periodontal apparatus. The procedures included maxillary Le Fort I osteotomy in segments (vertical intrusion, horizontal advancement,
and arch expansion); bilateral sagittal split ramus osteotomies (horizontal advancement and limited counterclockwise rotation); osseous genioplasty
(vertical shortening and horizontal advancement); and septoplasty, inferior turbinate reduction, and nasal floor recontouring. A, Frontal views with
smile before and after treatment. B, Profile views before and after treatment.

185
CHAPTER 6  Periodontal Considerations in the Evaluation and Treatment of Dentofacial Deformities
C
Prior to retreatment
Pre surgery
After treatment
D
Maxillary counter-
clockwise rotation
Mandibular counter-
clockwise rotation
Arch expansion
C, Occlusal views before retreatment, with orthodontics in progress, and then after treatment. D, Articulated dental
casts that indicate analytic model planning.
• Figure 6-15, cont’d

186
SECTION 1  Basic Principles and Concepts
• Figure 6-16  A woman in her late 20s was born with an isolated cleft palate. She underwent palate repair during
infancy, and she later developed a jaw deformity with malocclusion. Attempts to neutralize the occlusion included
years of growth modification and orthodontic mechanics with four bicuspid extractions between the ages of 11 and
17 years. The patient was left with generalized labial bone loss and gingival recession, especially of the lower anterior
teeth. She presented to this surgeon as an adult with a lifelong history of obstructed nasal breathing. She also had
a long face growth pattern that involved the maxilla, the mandible, and the chin and that included excess vertical
height and horizontal retrusion of those areas. She underwent periodontic, prosthodontic, orthodontic, surgical,
speech pathology, and ear, nose, and throat evaluations, among others. She received periodontal treatment and
then orthodontic decompensation. Her surgery included a Le Fort I osteotomy (horizontal advancement and clock­
wise rotation); bilateral sagittal split ramus osteotomies (horizontal advancement and counterclockwise rotation);
osseous genioplasty (vertical reduction and horizontal advancement); and septoplasty, inferior turbinate reduction,
and nasal floor recontouring (see Fig. 34-9). A, Frontal facial and occlusal views before retreatment. B, Profile view
and lateral cephalometric radiograph before retreatment.
Or
Or
Or
Or
O thththththththththththththtr ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatatatatatatatathicicicicicicicicicicicicicicicicicicicicicic Su
Su
Su
Su
Su
S rg
r ery
ry
ry
ry
ry; J.C.
C.
C.
C.
C.
C.
C.
C.
C.
C.
C.
C.
C.
C.
C. Pos
os
os
os
os
os
os
os
os
os
os
os
o nicicick
A
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orthththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatathicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C.
C.
C.
C.
C.
C Pos
osnicicick
B

187
CHAPTER 6  Periodontal Considerations in the Evaluation and Treatment of Dentofacial Deformities
• Figure 6-17  A 21-year-old college graduate arrived for surgical evaluation. The history and examination confirmed lifelong nasal
obstruction, lip incompetence, and gummy smile. Further inspection confirmed a long face growth pattern with a Class II anterior
open-bite malocclusion. The patient had been under an orthodontist’s care since the mixed dentition and throughout her high school
years. Growth modification, rapid palatal expansion, and full bracketing with four bicuspid extractions introduced dental compensa­
tion but without successful closure of the open bite. Early periodontal deterioration is evident. She agreed to a comprehensive dental
and facial rehabilitation approach. Periodontal evaluation and treatment followed by orthodontic (dental) decompensation and then
jaw and intranasal surgery were carried out (see Figure 21-5). A, Frontal view in repose and occlusal views before retreatment.
B, Profile view and lateral cephalometric radiograph before retreatment.
Or
Or
Or
Orththththththththththththththth
r ogn
gn
gn
gn
g atathicicicic Su
Su
Surg
r ery
ry
ry; J.C.
C.
C.
C.
C. Pos
os
os
os
os
os
os
os
os
os
os
os
os
os
o nicicick
A
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orthththththththththththththththththththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatatatatatatathicicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
S rg
r ery
ry; J.C.
C.
C. Pos
os
osnicicick
B

188
SECTION 1  Basic Principles and Concepts
• Figure 6-18  A woman in her mid 30s was referred by her orthodontist for surgical evaluation. She had a lifelong history of
obstructed nasal breathing and a long face growth pattern. Throughout her mid childhood and teenage years, she had under­
gone attempted growth modification followed by orthodontic camouflage, which included four bicuspid extractions with an
attempt to neutralize the occlusion. There is periodontal deterioration and dental relapse with residual malocclusion. The patient
agreed to a comprehensive surgical and dental rehabilitative approach. Periodontal treatment was followed by orthodontic
(dental) decompensation. Her surgery included maxillary Le Fort I osteotomy in segments (horizontal advancement, vertical
shortening, counterclockwise rotation, arch expansion, and curve of Spee correction); bilateral sagittal split ramus osteotomies
(horizontal advancement and counterclockwise rotation); osseous genioplasty (vertical reduction and horizontal advancement);
and septoplasty, inferior turbinate reduction, and nasal recontouring (see Fig. 25-8). A, Frontal facial and occlusal views before
retreatment. B, Profile view and lateral cephalometric radiograph before retreatment.
Or
Or
Or
Orthththththththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
g atathicicicic Su
Su
Su
S rg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C.
C.
C.
C Pos
os
os
os
os
os
os
os
os
os
os
os
os
os
os
os
o nicicici k
A
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
O thththththththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatatatatatatatatatathicicicicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C Pos
os
o nicick
B

189
CHAPTER 6  Periodontal Considerations in the Evaluation and Treatment of Dentofacial Deformities
• Figure 6-19  A woman in her late 40s with a long face growth pattern suffered deterioration of the dentition. The periodontal
risk factors included inadequate attached gingiva, dental root crowding within limited alveolar bone support, nasal airway
obstruction with forced mouth breathing, and lip incompetence that caused drying of the exposed gingiva. An attended poly­
somnogram confirmed obstructive sleep apnea. Unfavorable soft-tissue envelope distortions and premature facial aging were
also discussed. She agreed to a comprehensive surgical and dental rehabilitative approach. Periodontal treatment was followed
by restorative temporization and orthodontic alignment, including the extraction of the four first bicuspids. This was followed by
surgery that included maxillary Le Fort I osteotomy in segments (vertical shortening, horizontal advancement, transverse widen­
ing, and limited clockwise rotation); bilateral sagittal split ramus osteotomies (horizontal advancement and limited counterclock­
wise rotation); osseous genioplasty (vertical shortening and horizontal advancement); an anterior approach to the soft tissues
of the neck (cervical flap elevation, neck defatting, and vertical platysma muscle plication); and septoplasty, inferior turbinate
reduction, and nasal floor recontouring (see Fig. 25-3). A, Frontal facial and occlusal views before treatment. B, Profile view and
lateral cephalometric radiograph before treatment.
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orthththththththththtr ogn
gn
gn
gn
gnatatatatatatatatatatatata hicicicicicicicicicicicicicicici Su
Su
Su
Su
Su
Su
S rg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C.
C.
C.
C Pos
os
os
os
os
os
os
os
os
os
os
os
os
os
os
os
osnicici k
A
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Orththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatathicicicicicicicicicicicicicicicicicicic Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Su
Surg
r ery
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry
ry; J.C.
C. Pos
os
os
osnicici k
B