Orthognathic Surgery

441

15
Sequencing of Orthognathic
Procedures: Step-by-Step Approach
JEFFREY C. POSNICK, DMD, MD
• Description and Sequencing of Orthognathic
and Other Frequent Simultaneous
Procedures: Step-by-Step Approach
• Conclusions
Description and Sequencing of
Orthognathic and Other Frequent
Simultaneous Procedures:
Step-by-Step Approach
Preparation and Draping
Step 1. The patient is placed supine on the operating
room table with the head in a Mayfield (horse­
shoe) headrest in the neutral neck position.
Step 2. A nasotracheal cuffed (Ring-Adair-Elwyn [RAE])
tube is inserted by the anesthesiologist and then
secured by the surgeon to the cartilaginous septum
with suture (#0 Ethibond). An additional suture
(#0 Ethibond) is placed in the midline anterior
hair-bearing scalp and then around the endotra­
cheal tube extension over the top of the head to
further secure it and to limit tension on the nose
(Fig. 15-1).
Step 3. Ophthalmic antibiotic ointment and protective
corneal shields are placed beneath the eyelids (or
temporary tarsorrhaphies are performed, if pre­
ferred) to prevent corneal injury during the opera­
tion (Fig. 15-2, A through C).
Step 4. The anesthesiologist places monitoring equipment
for the safe delivery of deliberate hypotensive
anesthesia (i.e., arterial line, Foley catheter, large-
bore venous lines, pulse oximeter, carbon dioxide
monitor, and temperature probe). The bed is then
positioned at approximately 15 degrees reverse
Trendelenburg (see Chapter 11).
Step 5. Antibiotics (e.g., Cefazo­lin (Ancef ); 15 to 20 mg/
kg and up to 1 g) and steroids (e.g., Dexameth­
asone 0.5 mg/kg/dose, max: 8 mg) are adminis­
tered intravenously by the anesthesiologist.
Step 6. The head and neck are prepped with povidone–
iodine (Betadine) solution. Avoid using soap or
alcohol solutions that could irritate the cornea and
the mucous membranes. Draping should provide
for adequate exposure of the forehead, the eyes,
Maxillofacial surgeons and orthodontists are the primary
clinicians who care for individuals who present with jaw
deformities, malocclusions, and the associated facial dys­
morphologies. When an orthognathic approach is indi­
cated, there are a limited number of basic surgical techniques
that are used to facilitate the three-dimensional reposition­
ing of the skeletal units (i.e., the maxilla, the mandible, and
the chin region) to achieve desired improvements in head
and neck function and to enhance facial aesthetics. By and
large, these options include the Le Fort I (Type) osteotomy,
with or without segmentation of the down-fractured
maxilla; sagittal split ramus osteotomies of the mandible;
and an oblique osteotomy of the chin. Each of these three
basic osteotomies and its associated fixation techniques has
evolved gradually to its current usage (see Chapter 2).1-6
This chapter provides the surgeon with a step-by-step
technical description for the safe execution of Le Fort I
osteotomy of the maxilla, sagittal split ramus osteotomies
of the mandible, osseous genioplasty, and other frequent
simultaneously performed procedures (e.g., septoplasty,
reduction of inferior turbinates, recontouring of the nasal
floor, removal of wisdom teeth, neck region soft-tissue reju­
venation) as I routinely carry them out (
Video 6 and 7).
The approach is described as it is typically executed for
the patient who is undergoing all of these procedures simul­
taneously. An individual’s unique anatomy and clinical pre­
sentation may require variations in surgical approaches and
sequencing of treatment.

442 SECTION 2  Planning, Surgical Technique, & Complications
• Figure 15-1  Step 2.
Secure ET tube to nasal septum
Septal cartilage
the external ears, the face, and the neck. Staples
are used to secure the drapes (Fig. 15-3).
Step 7. The mouth and pharynx are suctioned, and a
moistened gauze with a radiopaque marker is
inserted as a throat pack. The teeth and dorsum
of the tongue are cleansed with a sterile tooth­
brush (1.5% hydrogen peroxide or 0.12%
chlorhexidine). The mouth is irrigated with
normal saline solution and suctioned.
Step 8. Steroid cream (e.g., betamethasone 0.5%) is
applied to the lips to limit edema that could
otherwise result from contusion during surgery.
Step 9. Lidocaine solution (Xylocaine 1% with 1 : 100,000
epinephrine) is infiltrated into the lateral vesti­
bules of the mandible, the facial vestibule of the
chin, and the labial vestibules of the maxilla.
Cortical Cuts for Sagittal Split Ramus
Osteotomies (
Video 6:2 and 7:2)
Step 10. A medium rubber mouth prop is placed between
the maxillary and mandibular molars on one side
to maintain mouth opening. Attention is turned
to the lateral vestibule of the contralateral
mandible.
Step 11. A. Incision Option One: No erupted wisdom
tooth for extraction. If there is no erupted
wisdom tooth to extract (i.e., if the wisdom
tooth is fully impacted, absent, or erupted and
is to remain in place), an incision is made with
a Bovie electrocautery device or a knife (no.
15 blade) in the depth of the vestibule adja­
cent to the second molar (Fig. 15-4, A). The
incision extends both anteriorly and posteri­
orly for a total length of 4 cm. The incision is
carried down to bone. A sufficient cuff of
mucosa is maintained adjacent to the gingiva
of the molar teeth for relaxed wound closure.
B and C.  Incision Option Two: Erupted or par­
tially erupted wisdom tooth for extraction. If
there is a partially erupted (Fig. 15-4, B) or
fully erupted (Fig. 15-4, C) wisdom tooth to
be removed, the incision starts 1 cm distal and
lateral to the wisdom tooth and extends to the
distobuccal line angle of the tooth. The inci­
sion continues anteriorly along the cervical
gingival margin of the tooth within the sulcus
and then anterior and lateral into the depth
of the vestibule. The incision is carried down
to bone. A sufficient cuff of mucosa, including
part of the papilla, is maintained adjacent to
the gingiva of the second molar for relaxed
wound closure.
Step 12. The subperiosteal dissection exposes the anterior
aspect of the lateral ramus and the posterior body
of the mandible down to the inferior border (Fig.
15-5, A). The extent of the dissection anterior to
the gonial angle depends on the planned buccal
extension of the proximal segment. The dissection
exposes the anterior superior aspect of the ramus
up toward the coronoid process, with stripping of
the temporalis muscle tendon (Fig. 15-5, B C ).
The dissection exposes the medial aspect of the
ramus superior toward the sigmoid notch and
inferior toward the mandibular canal (Fig. 15-6,
A). (I do not dissect below the inferior alveolar
neurovascular bundle or circumferentially around
it, because I believe this may cause additional
contusion and paresthesia.)
Step 13. Retraction of the soft tissues is performed with a
curved Kocher clamp on the coronoid process
(superior exposure); a channel retractor superior
to the neurovascular bundle (medial ramus
exposure); an inferior border retractor placed
anterior to the gonial angle (anterior expo­
sure); and a tongue retractor (lingual exposure)
(Fig. 15-6).
Step 14. With a sterile pencil, the osteotomy lines are
marked out for the sagittal splitting of the ramus
of the mandible. A reciprocating saw (i.e., with
a short, straight blade) completes the cortical
osteotomies.
A. The first cut is made horizontally through the
medial cortex of the ramus. This is judged to
be just superior to the occlusal plane of the
mandibular molars and well inferior to the
region of the anterior aspect of the ramus,
where the medial and lateral cortices join and
no longer maintain a medullary cavity. The
medial osteotomy need not extend more than
2 cm posterior (Hunsuck modification) (see
insert of Fig. 15-6, A). By keeping the medial
cut “low” (i.e., close to the mandibular molar
occlusal surface) and “short” (i.e., only 2 cm
back), the incidence of a “bad” split (i.e., with

443
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
• Figure 15-2  Step 3.
A
Placement of
ophthalmic
ointment
B
Placement of
corneal shield
Temporary tarsorraphy option
C

444 SECTION 2  Planning, Surgical Technique, & Complications
• Figure 15-3  Step 6.
• Figure 15-4  Step 11, A, B, and C.
A
B
C

445
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
• Figure 15-5  Step 12.
A
B
C
• Figure 15-6  Step 14, A, B, and C.
A
B
C

446 SECTION 2  Planning, Surgical Technique, & Complications
bone adjacent to the tooth and to section the
tooth to facilitate an atraumatic extraction.
Step 16. The wound is irrigated and suctioned. The retrac­
tors are removed, and two 1 inch × 3 inch cot­
tonoids are placed for packing (i.e., hemostasis).
One is placed along the medial ramus, and the
other is placed along the lateral body of the
mandible.
Step 17. Attention is turned to the contralateral ramus of
the mandible, and identical procedures to those
described in Steps 10 through 16 are carried out.
Maxillary (Le Fort I) Osteotomy
(
Video 6:3 and 7:3)
Step 18. With the use of a Tessier caliper, the vertical dis­
tance (height) between the medial canthus and
the mid-maxillary incisor crown is measured on
the left and right sides and recorded; this generally
measures between 55 mm and 70 mm (Fig. 15-7).
This is a reproducible relative measure of the ante­
rior vertical maxillary height (see Chapter 12).
the condyle as a third segment) is greatly
reduced.
B. The osteotomy then extends anteriorly and
just lateral (buccal) to the molars. It is impor­
tant that the saw blade penetrate the cortex
and enter the medullary cavity in all locations.
If the wisdom tooth is impacted, the saw
blade will bounce off the wisdom tooth just
after penetrating the superior paper-thin
cortex (Fig. 15-6, B); this will be just lateral
to the second molar. The blade will penetrate
back into the medullary cavity as the osteot­
omy progresses anterior past the impacted
tooth.
C. The reciprocating saw is then repositioned to
complete the vertical cortical osteotomy. The
osteotomy location will depend on the
planned buccal extension of the proximal
segment (i.e., the Dal Point modification.)
The vertical osteotomy begins at the inferior
border of the mandible, where the inferior
alveolar nerve is close to the cortex and prone
to laceration (Fig. 15-6, C). The osteotomy
then continues superiorly to join the cortical
osteotomy, which was previously completed
lateral to the molars.
COMMENT: When later “splitting” the ramus (see
Steps 53 through 58), as the inferior alveolar nerve
enters the mandibular foramen, it may remain within
either the proximal segment or the distal segment (see
Fig. 15-6, A inset). Traditional thinking is that the medial
osteotomy must remain above the mandibular foramen
as it extends posterior. I believe that it is more important
to keep the medial osteotomy low and short; this is a
reliable way to achieve a favorable split with limited risk
of the condylar component inadvertently remaining part
of the distal segment. After the low and short split is
completed, I do not favor the automatic need to
completely remove all aspects of the inferior alveolar
nerve that may remain within the proximal segment.
This is especially true at the mandibular foramen
location. I do not drill out or curette the inferior alveolar
nerve from the proximal segment unless it would
otherwise be under tension after repositioning the distal
segment. In my experience, however, this is not usually
the case.
Step 15. If the wisdom tooth is erupted and is to be
removed, then the extraction is completed now or
just before the cortical osteotomies; doing so
before the actual split will limit a fracture of the
lingual plate that may otherwise occur during
dental extraction. A rotary drill with a tapered
fissure bur may be used to judiciously remove
NOTE: If 70 mm is the baseline measurement and
3 mm of vertical intrusion at the incisors is a surgical
objective, then, after maxillary repositioning, 67 mm
should be the new measurement before the placement
of fixation across the Le Fort I osteotomy.
Step 19. Attention is turned to the vestibule of the maxilla
on one side. Two medium “toed-in” retractors are
used to retract the lip and cheek and thus expose
the vestibule. A circumvestibular incision is initi­
ated from the zygomatic buttress region anteriorly
toward the midline (Fig. 15-8). It is useful to
remain deep in the vestibule and to leave a full
cuff of mucosa adjacent to the attached gingiva of
the teeth. The most posterior aspect of the inci­
sion remains just anterior to and on the dental
(vestibular side) of the visualized parotid duct.
The incision is made with a Bovie electrocautery
device or a knife (#15 blade). Once the incision
is made through the mucosa the knife is directed
toward the dentoalveolar region and down to
bone. This will avoid injury to the infraorbital
nerve and limit the exposure of the buccal fat pad.
Step 20. Straight and curved elevators are used for the
subperiosteal dissection of the anterior maxilla
extending to and on either side of the infraorbital
nerve; extending medially to expose the pyriform
rim, the floor of the nose, and the anterior
nasal spine; and extending posterior to the ptery­
gomaxillary junction. A long “toed-out” retractor
is placed subperiosteally in the pterygomaxillary
space (Fig. 15-9).

447
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
• Figure 15-7  Step 18.
• Figure 15-8  Step 19.
Incision away from attached gingiva
Circumvestibular incision
• Figure 15-9  Step 20.

448 SECTION 2  Planning, Surgical Technique, & Complications
significant maxillary intrusion is planned, a second
parallel osteotomy line is marked out. The lower
marking (i.e., the osteotomy site) is placed to be
within the sinus, above the roots of the teeth, into
each lateral nasal aperture, and below each zygo­
matic buttress. If an ostectomy is to be preformed,
the upper marking is made superior and parallel
to the lower marking and below the infraorbital
nerves (Fig. 15-11).
Segmentation of the Maxilla
Step 24. If segmentation of the maxilla is to be completed,
the interdental osteotomies are initiated before
down-fracture. This provides a stable “workbench”
for the initiation of each interdental osteotomy.
Step 21. The two medium toed-in retractors are shifted to
the contralateral side of the maxilla, and the iden­
tical incision, dissection, and exposure are accom­
plished as described in Steps 19 and 20.
Step 22. Straight and curved elevators are used to further
separate the nasal mucosa from each lateral nasal
wall; the anterior nasal spine from the cartilagi­
nous septum; and the nasal mucosa from the floor
of the nose (Fig. 15-10).
Step 23. With four medium toed-in retractors (one on
either side of the infraorbital nerve on each side
of the maxilla) and two long toed-out retractors
(one in each pterygomaxillary junction) in place,
the anterior maxilla is fully visualized. A sterile
pencil is used to mark the location for the
horizontal Le Fort I osteotomy (Fig. 15-11). If
• Figure 15-10  Step 22.
• Figure 15-11  Step 23.

449
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
Maxillary (Le Fort I) Osteotomy: Continued
Step 25. With a reciprocating saw (i.e., a long straight
blade), the Le Fort I horizontal osteotomy is com­
pleted through the lateral, anterior, and medial
maxillary walls on each side (Fig. 15-13, A through
C). Before the medial maxillary osteotomy is com­
pleted, the lateral nasal mucosa is protected with
a small malleable retractor placed between the
lateral nasal wall and the nasal mucosa. Before the
lateral maxillary osteotomy is completed, the pter­
ygoid fossa soft tissues are protected with a long,
toed-out retractor.
Step 26. With a specialized guarded chisel and mallet, the
septum of the nose (i.e., cartilage and bone) is
separated from the maxilla. Care is taken to avoid
penetration past the septum into the nasopharynx
(Fig. 15-14).
Step 27. With a specialized curved chisel and mallet, the
pterygomaxillary suture is separated on each side
(Fig. 15-15). Care is taken to avoid injury to the
internal maxillary artery or to the pterygoid plexus
and to avoid perforation through the palatal
mucosa. For a patient with extreme maxillary
hypoplasia (e.g., Treacher Collins syndrome), the
The interdental osteotomies are typically made
either between the lateral incisor and the canine
on each side (Fig. 15-12, A) or between the
central incisors (Fig. 15-12, B). The subperiosteal
dissection of the gingival cuff provides adequate
exposure of each interdental osteotomy location
without the need for direct mucosa incisions.
Each interdental osteotomy site is marked with a
sterile pencil. The osteotomy is then initiated with
an oscillating saw (i.e., a short fan blade on a long
shaft) and later deepened after down-fracture with
the oscillating saw (i.e., a longer fan blade on a
long shaft).
• Figure 15-12  Step 24.
A
B
NOTE: The lateral incisor and canine roots—and, to
a lesser extent, the two central incisor roots—are
naturally divergent. Therefore, there is no advantage or
need for the orthodontist to create a gap for the
interdental osteotomy. Perforation into the periodontal
ligament space with injury to the dental roots when
completing these interdental osteotomies should be an
uncommon occurrence.

450 SECTION 2  Planning, Surgical Technique, & Complications
• Figure 15-13  Step 25.
A
B
C
• Figure 15-14  Step 26.

451
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
• Figure 15-15  Step 27.
chisel may be within millimeters of the optic
foramen and the optic nerve.
Step 28. With a Tessier (blunt) zygomatic hook placed on
the ledge of the nasal sill, force is applied to
“down-fracture” the Le Fort I osteotomy unit.
While down-fracturing, a Frazier suction tip and
a periosteal elevator are used by the assistant to
further separate and to limit the tearing of the
nasal mucosa (Fig. 15-16).
Step 29. After down-fracture, the maxillary sinus mucosa
is generally stripped off of its bony surfaces with
a Frazier suction tip and a hemostat (Fig. 15-17).
This is done to remove chronic inflammatory
tissue (polyps) from the sinus and to reduce
hemorrhage.
Step 30. Placing the Tessier (blunt) hook behind the maxil­
lary tuberosity and applying anterior and contra­
lateral directed force to one side at a time assists
with the disimpaction of the maxilla (Fig. 15-18).
The advantage of the Tessier hook is that it assists
with the mobilization of the maxilla without con­
tusion of the palatal mucosa, which may occur
with standard (Rowe) nasomaxillary disimpaction
forceps. When disimpacting with the Tessier hook
behind the tuberosity, the surgeon’s other hand is
used to grip the anterior maxilla (rather than the
teeth) and to apply simultaneous anterior and
contralateral force. This is helpful to prevent the
fracturing of the tuberosity by the Tessier hook.
This is repeated on each side two times to achieve
maximum disimpaction. During this process, the
assistant to the surgeon stabilizes the patient’s
head with one hand over each ear. For a maxillary
disimpaction that requires more extensive
advancement, the Rowe forceps may be required.
Septoplasty and the Reduction of
the Inferior Turbinates (
Video 6:4 and 7:4)
Step 31. When indicated on the basis of the patient’s
history and clinical examination, attention is
turned to the removal of the deviated portions of
the septum of the nose that are causing blockage
of the airway.
A. With an elevator, the submucosal dissection
of the cartilaginous septum (i.e., the quadran­
gular cartilage) and the bony septum (i.e., the
vomer and the perpendicular plate of the
ethmoid) is carried out (Fig. 15-19, A).
B. The deviated and thickened aspects of the car­
tilaginous septum and the bony septum are
resected with a rongeur (Fig. 15-19, B). The
more anterior components of the cartilagi­
nous septum that provides needed support to
the nasal dorsum and the tip are not dis­
turbed. This includes at least 1 cm of the
dorsal and caudal cartilage. When a maxillary
intrusion (i.e., for impaction) is planned, even
if septoplasty is not required to correct chronic
nasal obstruction, the inferior aspect of the
septum (i.e., the bone and cartilage) is removed
to prevent buckling.
Step 32. When indicated by the patient’s history and phys­
ical examination, attention is turned to reducing
each hypertrophic inferior turbinate that is causing
blockage of the airway. An incision is made
through the nasal mucosa just below and parallel
to each turbinate (Fig. 15-20, A). If the nasal
mucosa was torn during down-fracture, the
laceration is used and may be extended for
improved turbinate exposure. Each enlarged

452 SECTION 2  Planning, Surgical Technique, & Complications
• Figure 15-17  Step 29.
• Figure 15-16  Step 28.
Down-fracture of maxilla with intact nasal mucosa
inferior turbinate is visualized (Fig. 15-20, B), and
the inferior aspect of each is resected with a
straight Mayo scissors (Fig. 15-20, C). Hemostasis
is obtained along the cut edge of each turbinate
with the Bovie electrocautery device (Fig. 15-20,
D). The nasal mucosa is reapproximated with
interrupted sutures (3-0 Vicryl [polyglactin 910])
to create a closure that is as watertight as possible
(Fig. 15-20, E).
NOTE: To prevent a fire in the operative field, if
there are any air leaks around the nasotracheal tube,
then the electrocautery device is not used.
Removal of the Maxillary Wisdom Teeth
(
Video 6:5)
Impacted Wisdom Teeth
Step 33. A. If indicated, each bony impacted maxillary
wisdom tooth is removed through the sinus
floor (Fig. 15-21). A rotary drill with a small
watermelon bur is used to remove bone from
the sinus floor that is directly over the impacted

453
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
• Figure 15-18  Step 30.
Behind maxillary tuberosity
• Figure 15-19  Step 31, A and B.
Deviated septum
Nasal mucosa covering
inferior turbinates
A
B

454 SECTION 2  Planning, Surgical Technique, & Complications
• Figure 15-20  Step 32.
A
Inferior turbinate exposed after
elevation of nasal mucosal flaps
B
C
D
E

455
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
tooth. Next, using a rotary drill with a tapered
fissure bur, bone is removed adjacent to the
impacted tooth. Depending on the extent of
tooth development, the impacted wisdom
teeth may also be sectioned to assist with
removal. A dental elevator is used to remove
the tooth. Perforation through the palatal
mucosa is an uncommon occurrence.
Erupted Wisdom Teeth
B. If indicated, each erupted maxillary wisdom
tooth is removed before down-fracture. This
provides a stable “workbench” at the time of
extraction. To preserve maximum circulation
to the down-fractured maxilla, it is important
to minimize the disruption of the adjacent
palatal and labial mucosa at the time of
extraction.
Segmentation of the Maxilla: Continued
If segmentation of the maxilla is to be carried out, the
interdental cuts that were initiated previously are completed
during this stage.
Three Segments
Step 34. A. Description of a three-piece Le Fort I oste­
otomy with interdental cuts between the
lateral incisor and the canine on each side
connected to parasagittal osteotomies through
the hard palate:
(1) The parasagittal maxillary osteotomy is
completed through the down-fracture
using a reciprocating saw with a short,
straight blade. The osteotomy is from
• Figure 15-21  Step 33.
the posterior edge of the hard palate ante­
riorly to the pre maxillary region (Fig.
15-22, A-1).
(2) If the planned posterior arch-width
expansion is significant, then a second
parasagittal osteotomy is also completed
on the contralateral side (Fig. 15-22,
A-2). The two parallel parasagittal oste­
otomies allow for a more tension-free
expansion than a single osteotomy.
(3) The previously initiated interdental oste­
otomies are deepened using an oscillating
saw with a longer, fan blade on a long
shaft (Fig. 15-22, A-3).
(4) The oscillating saw with a longer, fan
blade on a long shaft is also used to
connect each interdental osteotomy to
the parasagittal osteotomy along the floor
of the nose at the level of the incisal
foramen (Fig. 15-22, A-4).
(5) A fine chisel (i.e., 5 mm or 7 mm in
width) is placed into the interdental oste­
otomy on the same side as the parasagittal
osteotomy, and an elevator is placed into
the parasagittal palatal osteotomy (Fig.
15-22, A-5). Twisting the elevator and
chisel simultaneously assists with the
splitting of the maxilla into segments.
(6) The fine chisel (i.e., 5 mm or 7 mm) is
then placed into the other interdental
osteotomy site, and an elevator is placed
in the nasal floor osteotomy site. With a
twisting motion, separation is completed
(Fig. 15-22, A-6). Perforation through
the palatal mucosa (when completing

456 SECTION 2  Planning, Surgical Technique, & Complications
Osteotomy across hard palate to
separate premaxillary segment
A1
A2
A3
A4
• Figure 15-22  A, Step 34, A, Part 1 through Part 4.

457
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
A5
A6
• Figure 15-22A, cont’d  Step 34, A, part 5, 6. B,
Continued

458 SECTION 2  Planning, Surgical Technique, & Complications
saw with a longer, fan blade on a long
shaft (Fig. 15-22, B-2).
(3) A fine chisel (i.e., 5 mm or 7 mm in
width) is placed into the interdental oste­
otomy, and an elevator is placed into the
parasagittal osteotomy. Twisting both
simultaneously assists with the splitting of
the maxilla into the two segments (Fig.
15-22, B-3). Perforation through the
palatal mucosa when completing the
parasagittal palatal osteotomy may occur.
The creation of a permanent palatonasal
fistula or the compromise of the circula­
tion to the maxillary segments should be
an uncommon occurrence.
Maxillary Le Fort I Osteotomy: Continued
(
Video 6: 6-10 and 7: 5-9)
Step 35. The maxillary segments are next secured into the
prefabricated acrylic intermediate occlusal splint
with the use of 26-gauge wire placed through
interdental drill holes in the splint and around the
orthodontic arch wire (Fig. 15-23).
the parasagittal palatal osteotomy) with a
reciprocating saw may occur. The creation
of a permanent palatonasal fistula or the
compromise of the circulation to the
maxillary segments should be an uncom­
mon occurrence (see Chapter 16).
Two Segments
B. Description of a two-piece Le Fort I osteot­
omy with an interdental cut between the
central incisors connected to parasagittal oste­
otomies through the hard palate:
(1) The parasagittal palatal osteotomy is com­
pleted through the down-fracture using a
reciprocating saw with a short, straight
blade from the posterior edge of the hard
palate anteriorly to the level of the incisive
foramen (Fig. 15-22, B-1). If the planned
posterior arch-width expansion is signifi­
cant, then a second parasagittal osteot­
omy is also completed on the contralateral
side.
(2) The previously initiated interdental oste­
otomy is deepened using an oscillating
B1
B2
B3
Step 34, B, Part 1 through Part 3.
• Figure 15-22B, cont’d

459
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
B. The Tessier caliper is used to measure the ante­
rior vertical dimension (i.e., the anterior facial
height) of the midface (i.e., the medial canthus
to the mid-maxillary incisor on each side) to
confirm that the desired vertical height is
achieved (Fig. 15-25, B).
Step 38. With the condyles remaining in the terminal
hinge position (i.e., the same position that they
were in when capturing centric relation in the
office setting) and with the maxilla in the pre­
ferred vertical location, appropriately sized and
individually contoured L-shaped titanium plates
(one by one) are most frequently placed across
each zygomatic buttress and at each lateral nasal
rim and secured with titanium screws (1.7 mm in
diameter and 4 mm in length) (Fig. 15-26).
Step 36. The maxillary segments are secured to the man­
dible in the occlusion established by the “interme­
diate” splint with the use of 26-gauge wire loops
passed around hooks located on the orthodontic
arch wires (Fig. 15-24).
Step 37. With the condyles seated in the terminal hinge
position (i.e., the same position that they were in
when capturing centric relation in the office
setting), the maxillomandibular com­plex
is
rotated to achieve the vertical dimen­sion that
was preoperatively determined (Fig. 15-25, A).
A. If vertical shortening (impaction) of the
maxilla is planned, this will require the
removal of bone interferences with rongeurs
or using a rotary drill with a water­
melon bur.
• Figure 15-23  Step 35.
• Figure 15-24  Step 36.
Intermediate splint

460 SECTION 2  Planning, Surgical Technique, & Complications
• Figure 15-25  Step 37, A and B.
A
B
• Figure 15-26  Step 38.

461
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
• Figure 15-27  Step 39, A and B.
A
B
Step 39. A. The jaws are unwired (Fig. 15-27, A).
B. With the condyles seated in the terminal
hinge position, the mandible is rotated verti­
cally
(up
and
down)
to
check
the occlusion. The occlusion must be found
to be even within the intermediate splint
(Fig. 15-27, B).
Step 40. A. After the occlusion is determined to be even,
the intermediate splint is removed.
B. The “final” splint is placed on the maxillary
teeth and secured to the orthodontic wire
(Fig. 15-28, A). This is accomplished with the
use of 26-gauge wires passed through the
interdental drill holes in the “final” splint
and around the orthodontic arch wire
(Fig. 15-28, B).
Step 41. When the extent of horizontal advancement and
vertical lengthening of the maxilla are judged to
be significant, then an interpositional bone graft
may be beneficial for the achievement of reliable
healing (Fig. 15-29, A). In these circumstances, I
prefer to use autogenous or allogenic iliac bone
graft. A bloc of corticocancellous bone is crafted
and tightly wedged into the gap on each side.
Each graft is inset in between the pyriform rim
and the zygomatic buttress titanium plates (Fig.
15-29, B). An additional plate is then contoured
to extend from the anterior maxilla above, across
the graft, and then onto the alveolar process of
the anterior maxilla. Titanium screws (1.2 mm
in diameter and 3 mm in length). then secure the
plate to the bone (Fig. 15-29, C).

462 SECTION 2  Planning, Surgical Technique, & Complications
nerve, with lateral exposure to the inferior border
of the mandible. There is no need to dissect above
the mental nerve on either side. If a 360-degree
dissection around the nerve is completed, it is
more likely that the nerve will be excessively
stretched or avulsed.
Step 45. A small S-shaped Tessier chin retractor is placed
on each side inferior to the mental nerve and later­
ally to the inferior border. A sterile pencil is used
to mark the location of the oblique osteotomy
(Fig. 15-32); this should be planned sufficiently
below the dental roots and the mental foramen
on each side. The exact location of the osteotomy
will depend on the presenting chin morphology
and the planned reconstruction (i.e., vertical
reduction or lengthening and extent of horizontal
advancement).
Step 46. Using an oscillating saw with a short fan blade on
a long shaft, a vertical groove is made in the
midline across and perpendicular to the proposed
horizontal osteotomy (Fig. 15-33, A). This will
help to maintain vertical orientation after the
osteotomy and before fixation.
Step 47. A drill hole is placed in the midline within the
distal chin (Fig. 15-33, B). Later, a screw (1.7 mm
in diameter and 8 mm in length) will be partially
inserted. The screw is not placed in the distal chin
until the osteotomy is completed. It will then be
held with a wire twister and used as a retractor
and a holder to facilitate the repositioning and
orientation of the distal chin unit.
Step 48. The oblique osteotomy of the chin is initiated in
the central portion using an oscillating saw with
a wide, fan blade on a short shaft (Fig. 15-34).
The use of this saw and blade helps to maintain
orientation and limit a cant in the osteotomy.
Step 49. The reciprocating saw with a short blade and then
with a longer blade is used to complete the lateral
aspects of the osteotomy and to go through the
Pyriform Rim, Nasal Floor, and Anterior Nasal
Spine Recontouring (
Video 6:9 and 7:7)
Step 42. The nasal aperture, the floor of the nose, and the
anterior nasal spine are inspected. Refinement and
recontouring of these structures using a rotary
drill with a watermelon bur are frequently benefi­
cial (Fig. 15-30). For example, in the patient with
vertical maxillary excess (i.e., long face growth
pattern), the deepening and recontouring of the
nasal floor, the pyriform rims, and the anterior
nasal spine will generally improve nasal airflow
(i.e., the correction of a tight nasal inlet and an
elevated nasal floor) and also enhance nasal aes­
thetics (i.e., limit unwanted alar base widening
and tip elevation).
Chin Osteotomy (
Video 6:11 and 7:10)
Step 43. Attention is next turned to the facial vestibule of
the chin. The lower lip is stretched outward to
allow for exposure of the vestibule and the visual­
ization of the mental nerve through the mucosa
on each side. In the depth of the vestibule, an
incision is made with the use of a Bovie electro­
cautery device or a knife (#15 blade) through the
mucosa from cuspid region to cuspid region, stop­
ping just short of the visualized mental nerve on
each side (Fig. 15-31). The center two thirds of
the incision are next extended down to bone. A
full cuff of mucosa and muscle is maintained adja­
cent to the attached gingiva of the anterior teeth.
This should allow for adequate layered wound
closure (i.e., involving muscle and mucosa)
without resulting periodontal sequelae.
Step 44. Dissection with an elevator exposes the anterior
surface of the chin (not completely to the inferior
border of the central chin). The dissection contin­
ues laterally and remains inferior to the mental
• Figure 15-28  Step 40, A and B.
Remove
intermediate
splint
Place
final
splint
A
B

463
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
• Figure 15-29  Step 41.
Additional microplate
and screws
C
B
A

464 SECTION 2  Planning, Surgical Technique, & Complications
watermelon bur to remove bone height at the
osteotomy line.
B. If a more significant vertical reduction is
planned, a second parallel osteotomy for
ostectomy is completed through the proximal
chin (below the dental roots) using a recipro­
cating saw with a long straight blade. Any
lateral irregularities are also removed using a
rotary drill with a watermelon bur. This is
to limit postoperative palpable or visible
step-offs.
Step 51. The distal chin is held in the desired position by
the assistant with the use of the wire twister
secured to the positioning screw. The surgeon
custom contours each titanium plate across the
osteotomy site and then secures each plate with
screws (1.7 mm in diameter and 4 mm in length).
Typically, either a three- or four-hole straight plate
is contoured with the ends placed on either side
of the osteotomy. The superior screw is usually
placed in between the lateral incisor and the
canine on each side. With the chin secured in its
new location, the positioning screw is removed
(Fig. 15-36, A and B).
Step 52. If significant vertical lengthening is carried out, an
interpositional graft (i.e., autograft, allograft, or
block hydroxyapatite) is crafted and placed in the
gap (Fig. 15-37). The graft fills the central gap in
between the fixation plates. I do not find it neces­
sary to place graft in the lateral aspect of the gaps.
depth of bone on each side (Fig. 15-35). An osteo­
tome may be inserted with a twisting motion to
complete the osteotomy separation.
Step 50. When vertical shortening of the chin is planned,
there are two options.
A. If only limited shortening is required in com­
bination with horizontal advancement, it
may be preferable to use a rotary drill with a
• Figure 15-30  Step 42.
• Figure 15-31  Step 43.

465
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
malleable to expose the medial cut) are placed for
sufficient exposure to complete the sagittal split­
ting of the ramus of the mandible.
Step 54. Initially, fine osteotomes (i.e., 5 mm and 7 mm
in width) are used with a mallet to confirm that
all cortical cuts are complete (Fig. 15-38). When
twisting the chisels, a degree of movement should
be visualized along the vertical cut down to the
inferior border. Care is taken to avoid injury to
the inferior alveolar nerve, which is located super­
ficial to the cortex along the inferior aspect of the
buccal shelf extension.
An additional plate with screws is generally placed
vertically in the midline across the osteotomy site
directly over the graft (see Chapter 18).
Sagittal Split Ramus Osteotomies: Continued
(
Video 6:12 and 7:11)
Step 53. Attention is returned to one side of the ramus of
the mandible. The previously placed packs are
removed and retractors (i.e., tongue, inferior
border at buccal extension, toed-in Langenbeck at
anterior ramus to retract the cheek, and medium
• Figure 15-32  Step 45.
• Figure 15-33  Steps 46 and 47.
A1
B1
A2
B2

466 SECTION 2  Planning, Surgical Technique, & Complications
is sometimes desirable. A thin periosteal elevator
may be used to gently tease the neurovascular
bundle free from the proximal segment. A rotary
drill with a watermelon bur may also be used to
release the neurovascular bundle from the proxi­
mal segment.
Step 55. A larger osteotome (10 mm in width) is then
placed deep into the medullary cavity near the
second molar of the mandible. A sagittal split
spreader forceps is placed deep into the medullary
cavity (i.e., more distal) in the buccal extension
region (Fig. 15-39). After both of these are in
place, a simultaneous twisting and spreading
motion is employed to complete the separation.
During separation, the neurovascular bundle is
visualized, and the correct separation of the condyle
(retained to the proximal segment) is confirmed.
Step 56. With the split complete, further freeing of the
neurovascular bundle from the proximal segment
• Figure 15-34  Step 48.
• Figure 15-35  Step 49.
NOTE: It is not usually necessary to completely free
the nerve from the proximal segment. Caution is
warranted, because a degree of contusion to the
neurovascular bundle will occur when doing so.

467
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
Removal of Impacted Mandibular
Wisdom Teeth (
Video 6:12)
Step 59. If present, each bony impacted mandibular
wisdom tooth located within the distal segment is
removed with a dental elevator (Fig. 15-40). It
may be helpful to use a rotary drill with a tapered
fissure bur to remove bone adjacent to the tooth.
Sectioning the tooth may be required to facilitate
Step 57. A curved Kocher clamp is placed on the distal
aspect of the proximal segment. The clamp is used
as a handle to apply force and to ensure the com­
plete separation and freedom of motion of the
proximal and distal segments (i.e., soft-tissue
release).
Step 58. The identical sagittal splitting of the ramus of the
mandible is completed on the contralateral side;
see Steps 51 through 57.
• Figure 15-36  Step 51.
• Figure 15-37  Step 52.

468 SECTION 2  Planning, Surgical Technique, & Complications
• Figure 15-38  Step 54.
• Figure 15-39  Step 55.
are wired together with 26-gauge wire loops
placed around the orthodontic interdental hooks
(Fig. 15-41).
Step 61. Attention is turned to the proximal segment of
the mandible on one side. The proximal segment
is seated with the condyle in the terminal hinge
position. This is accomplished with the placement
of a fine curved hemostat to the edge of the buccal
extension. The condyle will then rest in a superior
and anterior position within the glenoid fossa
(i.e., the same position that it was in when captur­
ing centric relation in the office setting). Any
interferences that prevent sufficient passive bone
contact of the proximal and distal segments along
the osteotomy site are managed using a rotary drill
with a watermelon bur (Fig. 15-42). If the man­
dible is set back, an appropriate section of bone is
also removed from the distal aspect of the proxi­
mal segment (i.e., the buccal shelf) to prevent
any cortex overlap. When setting the mandible
back, the removal of bone interferences from the
lingual plate of the distal segment is also generally
required. These tasks are accomplished using
either a rotary drill with a watermelon bur or a
reciprocating saw with a short, straight blade.
the atraumatic removal of the tooth. This will
minimize the chance for an uncontrolled fracture
of the lingual plate.
Sagittal Split Ramus Osteotomies: Continued
(
Video 6: 12-15 and 7: 11-14)
Step 60. The distal mandible is placed into occlusion
through the prefabricated final splint, which has
already been secured to the maxilla. The jaws
NOTE: The hemostat is not used to clamp the
proximal and distal segments together. Gentle superior
and posterior force is applied to seat the condyle in the
terminal hinge position.

469
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
Step 62. A 4-mm lateral neck incision (just below inferior
border of the mandible) is made through the skin
for trocar insertion (Fig. 15-43, A through C). The
location of the incision is based on the best posi­
tion of the trocar for ideal bicortical screw place­
ment. With the use of a straight hemostat, blunt
dissection through the skin incision is accom­
plished to achieve intraoral exposure. The trocar
is then introduced, and the cheek retractor com­
ponent of the trochar is placed to improve
visualization.
Step 63. The proximal segment is seated with the condyle
in the terminal hinge position. This is accom­
plished via the placement of a fine curved hemo­
stat to the edge of the buccal extension. (Note that
the hemostat is not used to clamp the proximal
and distal segments together.) Gentle superior and
posterior force is applied to seat the condyle in the
• Figure 15-40  Step 59.
• Figure 15-41  Step 60.
• Figure 15-42  Step 61.

470 SECTION 2  Planning, Surgical Technique, & Complications
• Figure 15-43  Step 62.
Trocar cheek retractor in place
Trocar inserted
Insertion of trocar
4-mm skin incision
A
B
C

471
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
terminal hinge position. The condyle will then
rest in a superior and anterior position within the
glenoid fossa (i.e., the same position that it was in
when capturing centric relation in the office
setting). Three bicortical titanium screws (2.3 mm
in diameter and 14 mm to 16 mm in length) are
generally sufficient to passively secure the proxi­
mal and distal segments together (Fig. 15-44, A
through C). The bicortical screws are placed in
locations where bone contact is the best. A fourth
screw is sometimes placed. Stability is further
improved when the screws are positioned as far
from each other as possible. Plates with unicorti­
cal screws are occasionally preferred to bicortical
screw fixation.
Step 64. Attention is turned to the contralateral side, and
identical procedures are carried out; see Steps 60
through 63.
Step 65. The jaws are then unwired. With the application
of posterior and superior vectored force to the
anterior mandible, the condyles are seated in the
terminal hinge position. The mandible is then
rotated (up and down) to check that the occlu­
sion is even and passive into the splint (Fig.
15-45). If not, the bicortical fixation screws are
removed, and the process is repeated; see Steps
59 through 63.
Wound Closure (
Video 6: 16 and 7: 15)
The anesthesiologist is asked to discontinue the deliberate
hypotensive anesthesia before wound closure. This should
unmask any significant bleeding vessels.
Step 66. The maxillary, mandibular, and chin vestibular
wounds are irrigated, suctioned, and checked for
hemostasis. The wounds are then closed with
interrupted suture (3-0 Vicryl and 3-0 chromic).
A. The mandibular vestibular wounds are gener­
ally closed in one layer with interrupted suture
(3-0 Vicryl). Running and locking (3-0
chromic) suture may be substituted (Fig.
15-46, A). A watertight closure is important
to prevent dehiscence followed by increased
risk of infection.
B. The maxillary wound is generally closed with
running and locking suture (3-0 chromic)
(Fig. 15-46, B). The risk of dehiscence or
infection is low.
C. The wound of the chin is closed in two layers
(i.e., muscle and mucosa). Three to five inter­
rupted buried sutures (3-0 Vicryl) are placed
for muscle layer closure. Locking and running
sutures (3-0 chromic) are used for the closure
of the mucosa layer (Fig. 15-46, C). A two-
layer closure is essential to limit dehiscence
and to prevent chin ptosis.
D. The trocar (skin) wounds are closed with two
interrupted sutures (6-0 nylon).
Step 67. The mouth is irrigated and suctioned, and the
throat pack is removed. An orogastric tube is
placed to drain the stomach and then removed.
Interdental elastics are applied to secure the
occlusion.
Anterior Neck Soft-Tissue Procedures
(
Video 7:16)
Step 68. If anterior neck soft-tissue management is planned,
it is carried out at this stage. This may include
cervical flap elevation, supra-platysma and sub-
platysma defatting, and vertical platysma muscle
plication (see Chapter 40). Additional prepping
with povidone–iodine (Betadine) solution is
carried out, and a sterile drape is placed over the
standard drapes that are already in place. Sterile
instruments and a fresh gown and gloves are used.
Injection with tumescent solution is completed in
the supra-platysma plane.
A. A 3-cm submental incision is made within or
just caudal to a natural submental crease.
B. Two double skin hooks are placed (i.e., one
on either side of the incision) to provide
tension on the flaps.
C. If the separation of the cervical skin from the
underlying platysma muscle is planned, it is
accomplished with a blunt-tipped scissors.
The cervical skin flap elevation off of the pla­
tysma muscle may continue laterally over the
sternocleidomastoid muscles inferiorly to the
thyroid cartilage and superiorly to the inferior
border of the mandible.
D. A cannula (no. #7 plastic curved) is used to
suction the fat above and in between the
platysma muscles.
E. Plication of the platysma muscle in the
midline (vertically) from above the thyroid
cartilage to just below the chin may also be
carried out with interrupted suture ties (3-0
Vicryl).
F. After confirming satisfactory hemostasis, the
submental skin wound is closed in two layers:
dermal (5-0 Vicryl) and skin (6-0 nylon).
G. A light pressure dressing (Jobst type) is gener­
ally applied to the neck. In general, I do not
find it necessary or useful to place a drain.
Emergence from Anesthesia
Step 69. The corneal shields or temporary tarsorrhaphies,
if used, are removed. The sutures used to secure
the endotracheal tube to the scalp and the septum
of the nose are released. When the appropriate

472 SECTION 2  Planning, Surgical Technique, & Complications
• Figure 15-44  Step 63.
Screwdriver inserted through trocar
3 bicortical screws (2.3 mm in diameter and 14-16mm in length) in place
Power drill (2.3-mm bit) inserted through trocar
Intraoral view with trocar in place
C
B
A

473
CHAPTER 15  Sequencing of Orthognathic Procedures: Step-by-Step Approach
physiologic parameters are met, the patient is
generally extubated in the operating room and
then taken to the recovery room breathing
spontaneously. If any airway need arises, the
interarch elastics are removed without concern
(see Chapter 11).
Conclusions
The surgical management of dentofacial deformities has
gradually evolved. By understanding the technical details
for the safe execution of the maxillary (Le Fort I), mandibu­
lar (sagittal splitting of the ramus), and chin (osseous genio­
plasty) osteotomies, each skeletal unit may be precisely and
efficiently repositioned (i.e., in three dimensions) during
one operation. Other simultaneous adjunctive procedures
(i.e., septoplasty; the reduction of the inferior turbinates;
• Figure 15-45  Step 65.
• Figure 15-46  Step 66, A, B, and C.
A
C
B

474 SECTION 2  Planning, Surgical Technique, & Complications
breathing, and lip closure) and to enhance facial aesthetics.
Special circumstances and unusual anatomy may require
variations of the techniques described in this chapter. The
development of a consistent approach for most routine cases
limits morbidity and increases efficiency of care.
the recontouring of the pyriform rims, the nasal base, and
the anterior nasal spine; the removal of wisdom teeth; and
soft-tissue neck rejuvenation) are routinely performed,
when indicated, to improve head and neck function (i.e.
occlusion, chewing, speech articulation, swallowing,
References
1. Luhr HG: Zur stabilen osteosynthese bei
unterkiefer–frakturen. Dtsch Zahnarztl Z
23:754, 1968.
2. Posnick JC, Fantuzzo JJ, Troost T:
Simultaneous intranasal procedures to improve
chronic obstructive nasal breathing in patients
undergoing maxillary (Le Fort I) osteotomy. J
Oral Maxillofac Surg 65:2273–2281, 2007.
3. Posnick JC: Le Fort I, sagittal split and
genioplasty: historical perspective and
step-by-step approach. In Posnick JC, editor:
Craniofacial and maxillofacial surgery in children
and young adults, Philadelphia, 2000, W.B.
Saunders Company, pp 1081–1102.
4. Obwegeser HL. In Trauner R, Obwegeser H,
editors: Zur operationstechnik bei der progenie
und anderen unterkieferanomalien. Dtsch
Zahn- Mund- u Kieferheilk 23:1–26, 1955.
5. Obwegeser HL: The surgical correction of
mandibular prognathism and retrognathia with
consideration of genioplasty. I. Surgical
procedures to correct mandibular prognathism
and reshaping of the chin. Oral Surg Oral Med
Oral Pathol 10:677–689, 1957.
6. Obwegeser HL: Der offene biss in chirurgischer
sicht. Schweiz Monatschr Zahnhlkd 74:668–687,
1964.

475

16
Complications Associated with
Orthognathic Surgery
JEFFREY C. POSNICK, DMD, MD
• General Considerations
• Risks and Complications Specific to Sagittal
Ramus Osteotomy of the Mandible
• Risks and Complications Specific to Le Fort I
Osteotomy
• Risks and Complications Specific to Oblique
Osteotomy of the Chin
• Conclusions
• Patient Education Materials
The definition of what constitutes a complication in
orthognathic surgery varies between both researchers and
clinicians, thereby making interstudy comparison difficult.
By understanding the medical history and physical findings
of the individual who presents with a dentofacial deformity
including 1) an awareness of any associated conditions or
malformations 2) the patient’s baseline psychosocial health
and 3) any head and neck dysfunctions—patient-specific
complications can be minimized. A thorough informed
consent process should also focus on patient-specific and
family-centered issues. The patient’s specific risk factors
should be presented to the individual and his or her family
for consideration before treatment.
Medical Risk Factors
An essential part of risk assessment includes the surgeon’s
performance of a thorough review of the patient’s medical
records and the completion of a history and physical exami­
nation. A general clearance examination by the patient’s
pediatrician or general physician and further confirmation
of the patient’s health through appropriate laboratory
testing is also important. The pregnancy testing of females
of childbearing age should be performed routinely the
morning of surgery.
For middle-aged adults who are considering orthogna­
thic surgery, additional medical risk factors may include
cardiovascular disease; obesity or increased body mass
index; obstructive sleep apnea; diabetes; pulmonary disease;
smoking history; the potential for deep vein thrombosis or
pulmonary embolus; and osteoporosis or the use of bisphos­
phonate treatment (see Chapter 25).30,50,172 Evaluation by
the patient’s primary care physician (and, in many cases, by
other medical specialists) and appropriate laboratory work
(e.g., electrocardiography, chest radiography, chemistries,
hematology, thyroid tests, coagulation studies) help to iden­
tify areas of concern. The adult patient with an elevated
body mass index who is undergoing surgery is at greater
than average risk for intraoperative and postoperative com­
plications. The presence of obstructive sleep apnea in the
General Considerations
No matter how accurate the diagnosis and how meticu­
lous the surgeon, complications will occur after orthogna­
thic procedures.* Alternatively, the relative safety of
orthognathic procedures has been confirmed by a number
of retrospective reviews.13,32,84,93,152,223,245,254,315,353 Panula and
colleagues reviewed maxillary and mandibular osteotomy
patients at their institution (N = 655) and found only one
serious complication (intraoperative bleed). A prospective
study of Le Fort I operations by Kramer and colleagues (N
= 1000) found a 6.4% incidence of complications that
ranged from extensive bleeding (1.1%) to sensory loss in
the distribution of the infraorbital nerve.173 A review by
Chow and colleagues of a consecutive series of orthognathic
patients (N = 1294) documented a relatively high complica­
tion rate (9.7%)61; this included mostly manageable “post­
operative infections” (7.4%), with no serious or rare events
recorded. A large series of orthognathic patients (N = 2049)
was reviewed by Van de Perre and colleagues346; those
authors identified one patient death and 44 other patients
with either primary or secondary complications.
*References 2, 23, 25-27, 42, 53, 78, 80, 83, 118, 146, 150, 157, 162,
186, 203, 206, 212, 224, 242-244, 246, 252, 262, 266, 314, 322, 328,
334, 335, 341-343, 345, 347, 355, 362-364.

476 SECTION 2  Planning, Surgical Technique, & Complications
• Figure 16-1  Perioperative risk to the airway and its management should be considered during all phases of orthognathic surgery, including
before nasotracheal intubation, during surgery, at the time of extubation, and soon after extubation. Individuals who are scheduled for orthog­
nathic surgery and who are recognized to be at high risk for airway compromise should be reviewed in advance with the anesthesia team
to arrange for special needs. Three patient examples in which these issues came into play are shown, including an adult with Noonan syn­
drome, a teenage girl with Treacher Collins syndrome, and a teenager with Klippel–Feil anomaly. Each of these patients also has the potential
for cervical spine anomalies with limited neck range of motion. The risk for spinal cord injury should also be evaluated before orthognathic
surgery.
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patient with a jaw deformity should be considered and ruled
out (see Chapter 26).
Wound-Healing Risk Factors
Specific patient factors that may impair wound healing
include diabetes mellitus, smoking, bisphosphonate treat­
ment for osteoporosis, poor nutritional status, and chronic
glucocorticoid exposure. Type II diabetes mellitus is fre­
quently a comorbidity of obesity and increased body mass
index. Alpha and colleagues documented a 66% incidence
of postoperative infections among diabetic patients under­
going maxillary or mandibular osteotomies, despite ade­
quately controlled glucose levels.9
The inhalation of nicotine via cigarettes affects both
pulmonary function and wound healing.72,75,95,264,137,149,176
Smoking or nicotine ingestion has been shown to delay the
chondrogenic phase of bone (osteotomy) healing and to
decrease the circulation of surgically elevated flaps, thereby
resulting in impaired healing after wound closure. Cigarette
smoke contains nicotine, carbon monoxide, and hydrogen
cyanide; each of these chemicals has been shown to impair
wound healing by producing relative tissue hypoxia. Nico­
tine is a vasoconstrictor that diminishes tissue oxygenation,
predisposes the individual to microvessel thrombosis (i.e.,
increased platelet adhesion and direct endothelial cell
damage), and diminishes cell proliferation and function.
Carbon monoxide reduces oxygen-carrying capacity, and
hydrogen cyanide inhibits oxidative metabolism and oxygen
transport. These consequences of cigarette smoke tissue
ischemia are most evident during healing after surgical pro­
cedures, when tissue circulation is at risk for interruption
(e.g., after microvascular tissue transfer, during the place­
ment of free [non-pedicled] bone grafts). A number of
clinical studies have documented increased morbidity in
patients who smoke and later undergo head and neck recon­
structive and aesthetic procedures. To minimize postopera­
tive wound difficulties and anesthesia-related pulmonary
complications, patients should be counseled to refrain from
smoking for at least 6 to 8 weeks preoperatively and for 2
to 4 weeks postoperatively. A serum or urine nicotine con­
centration can be obtained before surgery to confirm patient
compliance.
It is known that bisphosphonate treatment for osteoporosis
can affect osteoclast activity and that it may negatively
impact successful bone healing. Current guidelines con­
cerning bisphosphonate treatment continue to evolve and
should be followed when planning jaw or dentoalveolar
procedures.1,85,125,198,209,214,215,220-222,248,283,285,292,294,357,367
Perioperative Airway Risk Factors
Perioperative risk to the airway and its management
should be considered during all phases of surgical care,
including before nasotracheal intubation, during surgery,
at the time of extubation, and soon after extubation (Fig.
16-1).53,61,76,170,175,250 The basic clinical preoperative airway
assessment should include 1) measurements of mandibular
range of motion (i.e., vertical opening and protrusion);
neck mobility 2) Mallampati classification 3) the ratio of
the patient’s height to the thyromental distance 4) neck
circumference and 5) body mass index. A Mallampati clas­
sification of III or IV or a ratio of height to thyromental
distance of more than 23.5 is a strong indicator of a difficult

477
CHAPTER 16  Complications Associated with Orthognathic Surgery
hours postoperatively, a cardiac arrest occurred, and attempts
to resuscitate the patient failed. The cause was thought to
be preexisting cardiomyopathy. A death was also reported
by Waack and colleagues as part of a limited series of 63
consecutive Le Fort I osteotomies.216 The death occurred in
a healthy 15-year-old female patient on the first postopera­
tive day as a result of unknown causes.
Cervical Spine Risk Factors
As part of the presurgical assessment, the evaluation of the
patient’s cervical spine is essential. Congenital malforma­
tions, previous trauma, and arthritis are occasional etiologies
of cervical spine problems in the orthognathic patient.
Patients with specific syndromes (e.g., Klippel–Feil anomaly,
hemifacial microsomia, Treacher Collins syndrome, Apert
syndrome) are at higher risk for a cervical spine malforma­
tion that may be undiagnosed at presentation to the orthog­
nathic surgeon (see Fig. 16-1). Referral for evaluation by an
orthopedic spine surgeon, a neurosurgeon and a geneticist
as well as appropriate radiographic studies (e.g., magnetic
resonance imaging, computed tomography) are carried out
when indicated. Controlled positioning with limited
flexion, extension, and rotation at the time of intubation,
intraoperatively, and during recovery may be required. In
some cases, intraoperative neuro-monitoring (e.g., motor and
sensory) is useful to confirm minimal spinal compression
during surgery.
Psychosocial Risk Factors
To minimize patient and family disappointment after
surgery, an informal (or, in some cases, a more rigorous)
psychosocial assessment is conducted.24,36,73,81,167,304,317 All
parties involved must accept the risks and limitations of the
planned surgical procedures. Unfortunately, neither the pre­
operative psychosocial assessment nor the individual’s bio­
logic wound-healing ability is completely predictable. A
small percentage of patients will perceive an unfavorable
surgical outcome, even when the clinicians feel that the
results are at least satisfactory. Others will not accept a
complication, even though the risks were fully explained in
advance and all precautions were taken.
Body dysmorphic disorder is a medical condition that can
be difficult to recognize before surgery but that will rou­
tinely result in postoperative patient dissatisfaction. It
is estimated that 7% to 15% of individuals who pursue
cosmetic surgery have body dysmorphic disorder (see
Chapter 7).
Comprehensive Dental Rehabilitation Needs
Recognizing when a patient who is seeking orthognathic
surgery has dental needs that go beyond standard orthodon­
tics is essential to the achievement of an optimal outcome
(see Chapter 5). If complex dental restorations and peri­
odontal management are necessary, then planning should
airway with conventional direct laryngoscopy. A neck cir­
cumference of more than 17 inches in men is a risk factor
for obstructive sleep apnea. Individuals who are scheduled
to undergo orthognathic surgery may have special medical
risk factors that include baseline malformations or syn­
dromes and associated abnormalities that carry the potential
for difficult airway control (see Chapter 11). In the high-risk
patient, advance discussion with the anesthesia team to
arrange for an anesthesiologist who is experienced with dif­
ficult away management and who is skilled with awake
fiber-optic intubation may be indicated (see Fig. 16-1)
(
Video 5). After the nasotracheal tube is in place, the
surgeon secures it and assists with its management during
the operation (see Chapter 15). Complications associated
with endotracheal tubes that are placed for orthognathic
procedures have included herniation of the airway tube cuff
leading to occlusion of the tube lumen; inadvertent surgical
sectioning of the endotracheal tube; and the occurrence of
contact granuloma of the vocal cords.62,249 Acute intraopera­
tive or postoperative pulmonary edema, postoperative
apnea, pneumomediastinum, and pneumothorax have all
been reported as complications associated with anesthesia
(see Chapter 11).14,33,34,56,91,117,122,153,217,233,245,259,318,321
Malignant hyperpyrexia involves an abnormality of muscle
metabolism of genetic origin that manifests as widespread
skeletal muscle contraction, hypercatabolism, and hyper­
thermia upon exposure to volatile anesthetic agents
or succinylcholine.192,223,365 It is a serious condition that
requires prompt diagnosis and aggressive management. It
may occur during an orthognathic procedure with a typical
initial intraoperative presentation of tachycardia and notice­
ably warm skin.
Decisions about the timing of extubation after surgery
should be made by clinicians on the basis of extubation
criteria and patient-specific risk factors.159,376 In general, the
surgeon is present at the time of extubation in case either
emergency tracheostomy or reintubation is required. Our
preference is to extubate the patient in the operating room
when feasible but only when specific parameters are met.
For the patient with an ongoing difficult airway, a more
delayed approach to extubation maybe taken. The risk of
inadequate ventilation after extubation is highest when pre-
extubation parameters are not adequately met and when
excess sedation remains (see Chapter 11).
Spontaneous leg compartment syndrome has been reported
as a complication after orthognathic surgery.204 The occur­
rence is thought to be the result of a drug interaction
between anesthetic or postoperative medications or the
effect of antidepressive drugs that are superimposed on
chronic mild exercise-induced compartment syndrome.
Death is recognized as an exceedingly rare complication
related to orthognathic procedures. Of the numerous large
case series published, only one death has been described;
this was reported by Van de Perre and colleagues from a
series of 2049 patients.210 It occurred in a 17-year-old male
patient who was described as being slightly mentally chal­
lenged and who underwent bimaxillary osteotomies. Six

478 SECTION 2  Planning, Surgical Technique, & Complications
symptoms in a majority of patients after successful ortho­
dontics and orthognathic surgery, whereas some of the
study patients show deterioration. The favorable effects of
orthognathic surgery for patients with preexisting temporo­
mandibular joint symptoms may result from the improved
occlusion, the corrected facial height and horizontal projec­
tion, and the reduced emotional stress (or the placebo
effect). Varied degrees of documented radiographic condy­
lar remodeling after orthodontics and orthognathic surgery
have been reported in some patients. Interestingly, TMJ
radiographic findings do not necessarily correlate with
symptomatic temporomandibular disorders (see Chapters 9
and 37).
Management of Third Molars
Historically, the presence of impacted third molars during
a sagittal ramus osteotomy (SRO) of the mandible has been
presumed to be associated with increased complications
including the following: 1) a higher incidence of “bad splits”
2) a higher incidence of infection 3) issues with the place­
ment of fixation (i.e., osteotomy stabilization) and 4) dif­
ficulties maintaining the integrity of the inferior alveolar
nerve (IAN). It is for these reasons that, in the past, the
removal of impacted mandibular third molars 6 to 12
months before an SRO was routinely recommended.
However, the arguments against this approach are that this
subjects the patient to two surgeries, two anesthetic treat­
ments, and two recovery periods rather than just one and
that this staged approach may in fact increase rather than
decrease the previously mentioned complications.
Clinical studies have now documented no increased risk
of unfavorable or so-called “bad splits” when SROs are
performed in patients with impacted third molars as com­
pared with those without third molars.90,218,268,276,348 Doucet
and colleagues laid this argument to rest with their prospec­
tive cohort study that looked at the effects of the presence
or absence of third molars during SRO on 1) the frequency
of unfavorable fractures 2) the degree of entrapment of the
IAN in the proximal segment and 3) the procedural time
required to move the teeth.89 The study included patients
who were scheduled to undergo SRO to correct a dentofa­
cial deformity. Study patients were divided into two sub­
groups: Group I was made up of those with an impacted
mandibular wisdom tooth at the time of SRO (n = 331;
mean age, 19.6 years); Group II included those without a
mandibular wisdom tooth at the time of SRO (n = 346;
mean age, 30.4 years). The overall incidence of unfavorable
fractures was 3.1% (21 out of 677), with frequencies of
2.4% (8 out of 331) in Group I and 3.8% (13 out of 346)
in Group II. Interestingly, the rate of IAN entrapment in
coordinate care for these needs at the beginning of treat­
ment (see Chapter 6). This is especially true for the indi­
vidual with a cleft lip and palate or a craniofacial syndrome
(see Chapters 28 through 34). It is also true for the adult
who has suffered dental and periodontal sequelae from an
uncorrected dentofacial deformity or previous treatment
(e.g., orthodontics, restorative care) (see Chapter 25).
Functional Assessment of Head
and Neck Structures
The orthognathic surgeon should evaluate the patient’s
baseline head and neck functions, including speech,
swallowing, mastication, neck and mandibular range
of motion, breathing, hearing, vision, cognition, and
psychosocial competence. Any of these functions may
be negatively affected by the presenting maxillofacial
deformity or malformation and influenced (either favor­
ably or unfavorably) by the treatment being contem­
plated.94,113,139,163,228,232,311,313,320,377 A candid discussion with
the patient and the family about the potential impact of the
planned procedures on any of these functions should take
place before treatment.
Operating Room Team Preparation
Limiting risks and complications requires an informed
patient and family, coordinated collaborative comprehen­
sive clinical care, an experienced and focused surgeon,
meticulous planning, a dedicated operating room team,
effective postoperative hospital care, and appropriate out­
patient management. The operating room team includes the
surgeon and his or her assistants, the anesthesiologist and
his or her assistants, the operating room personnel (e.g.,
scrub nurse/technician, circulating nurse), and the full
complement of sterilized and organized instrumentation
(e.g., inventory, sanitation and sterilization personnel). The
instrumentation includes power saws and drills, with their
associated bits and blades; handheld instruments; and fixa­
tion hardware such as plates and screws. Specific medica­
tions, sutures, and dressing materials are also required. The
confirmation of the prepared operating room team, equip­
ment, instrumentation, and medications should be under­
taken before the patient enters the operating room. The
anesthesiologist and the surgeon should discuss the patient’s
airway and his or her intraoperative and postoperative
needs before entering the operating room (see Chapter 11).
After the equipment, instrumentation, and medications are
set up and checked and the team is briefed, the patient
may enter the operating room with the best opportunity
for success.
Temporomandibular Disorders
The effects of orthognathic surgery on temporoman­
dibular joint function are often specific to the patient
and cannot be fully predicted.11,82,138,139,156,247 Many clinical
studies report improvement in temporomandibular joint
NOTE:  When the removal of impacted mandibular
third molars is recommended to the patient for
long-term dental health, it is generally this author’s
preference to do so at the time of orthognathic surgery
(Fig. 16-2, A).

479
CHAPTER 16  Complications Associated with Orthognathic Surgery
the proximal segment was significantly lower in Group I
(37.2%) than in Group II (46.5%). The removal of third
molars at the time of SRO increased procedural time by
only 1.7 minutes.
As documented in published studies, this author has not
experienced increased levels of complications (e.g., infec­
tion, bad split, inability to place fixation, increased inci­
dence of inferior alveolar paresthesia) by doing so.
Exceptions to the routine removal of impacted wisdom
teeth at the time of orthognathic surgery may include
a severely hypoplastic mandible that requires extensive
advancement (i.e., in certain patients with hemifacial micro­
somia or Treacher Collins syndrome). In such cases, maximal
ramus region bone stock is needed for osteotomy stabiliza­
tion and healing. For those few patients, the preoperative
removal of the wisdom teeth followed by adequate time for
sufficient bone fill (i.e., 12 months) may be preferred.
When the removal of erupted or partially erupted man­
dibular wisdom teeth is carried out at the time of SRO, the
standard vestibular incision for SRO is altered to achieve
access to the erupted wisdom teeth and then for watertight
wound closure (Fig. 16-2, B) (also see Chapter 15). In
review, when considering evidence-based medicine, the routine
practice of the removal of wisdom teeth before SRO can no
longer be justified.
When removing impacted maxillary wisdom teeth, access
through the floor of the antrum after down-fracture at the
time of Le Fort I osteotomy represents this author’s usual
approach (Fig. 16-2, C ). The exception is when carrying
out segmental osteotomies in a cleft maxilla in conjunction
with extensive horizontal advancement of the lesser segment.
In these cases, the removal of the wisdom tooth in the lesser
segment may significantly diminish bone volume with
potential compromise of stabilization and healing.
The removal of an erupted or partially erupted maxillary
wisdom tooth is completed through the gingival opening
before down-fracture. When this is done, minimal flap
elevation is essential so as not to compromise maxillary
perfusion after down-fracture.
Fixation Considerations
Need to Remove Plates and Screws
Metal plates and screws have been used to stabilize fractures
and osteotomies in the maxillofacial region for more than
40 years.8,9,12,39,46,47,104,131,151,164,225,281,336 The metals that were
initially used were stainless steel and vitalium; these were
followed by titanium and its alloys.
There is both laboratory and clinical evidence of the
tissue compatibility and the high corrosion resistance of
titanium and its alloys in the human body. In 1991, the
Strasbourg Osteosynthesis Research Group recommended
that “the removal of a non-functional plate is desirable
provided that the procedure does not cause undue risk to
the patient.”32A,355A During earlier years, those who were
advocating the routine removal of fixation devices after
stable bone union felt that the implant had significant
potential to cause problems, so its removal was considered
preventative. Today, clinicians agree that the medical risk
and financial costs incurred by the routine removal of
asymptomatic fixation hardware cannot be justified. It is
currently standard practice to remove fixation plates and
screws only when clinically indicated.
Becelli and colleagues completed a retrospective
analysis of complications of bicortical screws used for sagit­
tal split ramus osteotomy (SSRO) fixation.22 The authors
reviewed a consecutive series of patients (N = 241) who
were undergoing sagittal ramus osteotomies (N = 482) for
skeletal Class III deformities. Complications related to
bicortical titanium screws were observed at 3% of the oste­
otomy sites (Fig. 16-3). The hardware was eventually
removed in these patients (15 out of 482), without long-
term consequences.
The indications for removal fall into the following cate­
gories: 1) a palpable and bothersome piriform aperture plate
or screw at the Le Fort I osteotomy site when the skin is
compressed against it with a finger; 2) a palpable and both­
ersome zygomatic buttress plate when a food bolus com­
presses against it while chewing; 3) an exposed bicortical
screw head in the labial vestibule at the SSRO site; 4) a
screw in close contact with a dental root that is symptom­
atic; and 5) a bicortical screw that extends through the
lingual cortex of the ramus and that causes discomfort or
concern, either during movement of the tongue or upon
contact with food during swallowing. Under these circum­
stances, the elective removal of the involved plate or screw
is carried out after osteotomy healing has occurred (i.e.,
preferably 6 to 12 months after surgery).
Use of Titanium versus Resorbable Fixation
The use of self-reinforced biodegradable bone plates
and screws has been advocated for use in orthognathic
surgery by a limited number of surgeons throughout the
world.92,96,127,130,155,165,178,297,325,344,345 Although this type of
fixation is appealing in theory, a greater incidence of post­
operative complications has been found with resorbable
fixation devices as compared with titanium. Furthermore,
no advantages in the achievement of improved skeletal sta­
bility have been documented with the use of biodegradable
hardware.
Turvey and colleagues reported about 70 patients who
were undergoing 194 osteotomies of the maxilla or the
mandible and who were stabilized with self-reinforced poly­
lactate bone plates or screws of similar size and configura­
tion to those of titanium systems.344 The placement of the
devices was accomplished transorally and transfacially in a
way that was consistent with the osteotomy location. Maxil­
lomandibular elastics were used for each patient after
NOTE:  In this author’s personal series of
orthognathic procedures from more than 27 years of
clinical practice, the need to or a request by the patient
to remove a plate or screw after healing has involved
less than 2% of individuals (Fig. 16-3).

480 SECTION 2  Planning, Surgical Technique, & Complications
• Figure 16-2  A, Illustration of an impacted mandibular wisdom tooth being removed in conjunction with sagittal ramus osteotomy. B, Illustrations
of incision options that are used for ramus osteotomy exposure and then for wound closure. The incision used is dependent on wisdom tooth
location. C, Illustrations of the removal of an impacted maxillary wisdom tooth through the sinus after Le Fort I down-fracture.
A
B1
B2
C

481
CHAPTER 16  Complications Associated with Orthognathic Surgery
patients with titanium plates and screws, there was a com­
plication rate of 8.6% (N = 13). Of the 120 patients with
resorbable plates and screws, 18.3% (N = 22) developed
complications. There was a greater degree of postoperative
infections and malocclusions and a trend toward relapse
observed in patients with resorbable plate and screw fixa­
tion. Three of the patients with resorbable plate and screw
fixation required reoperation for residual malocclusion as
compared with zero in the titanium group.
Infection Associated with
Orthognathic Procedures
Infection after orthognathic surgery is considered by most
to be uncommon. However, a review of the literature indi­
cates a wide range in the reported incidence of this compli­
cation.* A critical review of these studies provides insight
into the true incidence of infection, clinical pitfalls to con­
sider, and methods to use to best limit these sequelae.
All transoral wounds must be considered “clean-
contaminated wounds,” with an anticipated theoretical
infection rate of as high as 15%.352 It is said that this inci­
dence of infection in a clean-contaminated site can be
reduced to as low as 1% with good surgical technique and
the appropriate use of prophylactic antibiotics. The ques­
tion remains of how to best provide this type of antibiotic
coverage for the orthognathic surgery patient. According
to the infectious disease literature, antibiotic prophylaxis
should provide adequate drug levels in the tissue before,
during, and for the shortest possible time after surgery to
provide a reduced infection rate; be an effective agent
against the bacteria that are most likely to cause the infec­
tion; and be bactericidal while at the same time being the
least toxic agent available.
Spaey and colleagues reported a 4% prevalence rate of
infection after orthognathic procedures in their cohort.312
Among the infections that were sustained, 92% occurred at
the SSRO site, 1% occurred at the Le Fort I osteotomy site,
and only 0.5% involved the chin osteotomy location (Figs.
16-4 through 16-7). In their pilot study group, after comple­
tion of an SSRO, the authors placed a drain through the
mandibular vestibule mucosa incision; this was removed the
following morning. The prophylactic antibiotic regimen
that was initially used did not have a drug level in place while
the drain remained in or after its removal. Because of the
high infection rate observed in the pilot study, the research­
ers changed the protocol to no longer involve the placement
of a drain; to achieve a more meticulous mucosal wound
closure; and to extend the time of prophylactic antibiotic
use to 5 days after surgery. As a result, the infection rate at
the SSRO site was dramatically decreased. The authors con­
cluded that, in addition to an extended use of prophylactic
antibiotics, the achievement of a sealed vestibular wound at
the SSRO is essential to limit the infection rate.
surgery to control the position of the jaws. Three out of the
70 patients (4%) experienced immediate postoperative loos­
ening of the resorbable bone screws. Each of the patients
required a return to the operating room for more rigid
stabilization at the involved osteotomy site. Although all
patients eventually achieved acceptable occlusion, a number
of fixation sequelae occurred during the healing phase,
including prolonged mobility of the maxilla; sterile abscess
requiring debridement; swelling with sterile fistula tract
formation; and intranasal inflammation requiring fixation
removal at the time of secondary septoplasty. Although the
authors demonstrated that biodegradable plates and screws
could be used for orthognathic surgery, there was no advan­
tage when this was compared with titanium fixation devices,
and the complication rate is increased.
In a second study, Turvey and colleagues reported about
69 patients who were undergoing sagittal split ramus oste­
otomies for mandibular advancement.345 Thirty-four of
these patients underwent fixation with self-reinforced bio­
degradable screws, whereas 35 patients underwent fixation
with 2-mm titanium screws. Postoperatively, one of the
patients with biodegradable screws required a return to the
operating room for improved fixation. Again, no advantage
could be demonstrated with the use of biodegradable fixa­
tion, whereas a degree of diminished levels of stabilization
and increased complications were shown to be present.
Ahn and colleagues completed a study to evaluate the
complications of resorbable versus nonresorbable plate and
screw fixation in orthognathic surgery.3 Patients were
enrolled in the prospective study (N = 272). Titanium
plates and screws were used at the osteotomy sites in Group
I (N = 152), and resorbable plates and screws were used at
the osteotomy sites in Group II (N = 120). In the 152
• Figure 16-3  An 18-year-old with a bilateral cleft lip and palate jaw
deformity underwent cleft–orthognathic surgery including maxillary Le
Fort I osteotomy in three segments and interpositional iliac bone graft­
ing. Healing was uncomplicated, with the achievement of the planned
improvements. One year after surgery, the patient returned with a
complaint of a painless ridge in the left buccal vestibule of the maxilla.
Examination confirmed an exposed titanium plate and screw. There
were no associated symptoms or signs of infection. During an office
procedure, the exposed plate was sectioned with a wire cutter and
removed. Healing was uneventful.
*References 19, 20, 29, 48, 49, 77, 103, 105, 107, 108, 110, 111, 119,
133, 158, 171, 201, 213, 257, 279, 282, 284, 312, 319, 350, 375, 379.

Orth
r ognathic Surg
r ery; J.C. Posnick
A
Orth
r ognathic Surg
r ery; J.C. Posnick
Orth
r ognathic Surg
r ery; J.C. Posnick
B
• Figure 16-4  A woman in her early 30s with a primary mandibular deficiency growth pattern underwent a comprehensive orthodontic and surgical
correction. This required the removal of dental compensation, including opening upper bicuspid extraction spaces for dental implants. Surgery
included bilateral sagittal split ramus osteotomies, an osseous genioplasty, and anterior neck soft-tissue procedures. In-hospital and early at-home
convalescence proceeded without incident. Five weeks after surgery, the patient returned to a more normal diet, to regular physical activities, and
to her orthodontist’s care. Two months after surgery, pain in the left mandibular second molar region with chewing was persistent. The tooth was
also tender to percussion. A periapical radiograph revealed the proximity of a bicortical fixation screw to the distal root, with possible apical root
resorption. The removal of the involved screw was offered. However, the patient chose root canal therapy followed by the relief of pain and the
resolution of percussion tenderness. A, Profile and lateral cephalometric views before treatment. B, Oblique facial views before and after
treatment.

483
CHAPTER 16  Complications Associated with Orthognathic Surgery
C
After root canaltherapy T#18
E
D
C, Pretreatment and posttreatment lateral cephalometric radiographs. D, Left side
Panorex image 2 months after surgery, with left mandibular second molar pain with chewing. E, A periapical
radiograph is shown before and after successful root canal therapy (see Fig. 19-8).
• Figure 16-4, cont’d 
In a randomized, double-blind study, Ruggles and col­
leagues tested two different antibiotic regimens in patients
undergoing orthognathic surgery.284 Both groups received
preoperative and intraoperative antibiotics, whereas only
one group continued 48 hours of postoperative coverage.
The group that received no postoperative antibiotics had a
15% infection rate, whereas no infections were found in the
group with extended antibiotic coverage.
Danda and colleagues completed a prospective study to
evaluate the use of prophylactic antibiotics among patients
who were undergoing orthognathic surgery.78 The study
patients (N = 150) were divided into two groups. Group I
(N = 75) received a single dose of antibiotic prophylaxis.
Group II (N = 75) received a full day of antibiotic prophy­
laxis. In Group I, 9.3% of patients (N = 7) developed
infection, whereas only 2.6% (N = 2) of Group II patients
did. The results indicate a clinically significant increased rate
of infection with single-dose antibiotic prophylaxis as com­
pared with a full day of antibiotic prophylaxis.
Kublefelt and colleagues reported on smoking as a
significant risk factor for infection after orthognathic
surgery.176A This was a retrospective cohort study of indi­
viduals (n = 286) who were undergoing one-jaw orthogna­
thic surgery (i.e., bilateral SSRO [BSSRO] or Le Fort I
osteotomy) during a 7-year period. All patients received a
1-week course of antibiotics. Patients ranged in age from 17
to 56.5 years (mean, 34.8 years). The overall infection rate
was 9.1%. The only statistically significant identified risk
factor for infection in these study groups was smoking
history. The incidence of infection was 14.4% among

484 SECTION 2  Planning, Surgical Technique, & Complications
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gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatatatatatatatatatatathicicicicicicicicicicicicicicicicicic 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
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
ry
ry
ry
ry; J.C.
C.
C.
C.
C Pos
os
os
os
os
os
os
os
os
os
os
os
os
os
o nicicici k
A
Orthodontic decompensation in progress
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or
Or hthththththththththththththththththth
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 atatatatatatatatatatatatatatatatatatatatatata hicicicicicicicicicicicicicicicicicicicicicic 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.
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
os
os
os
os
os
os
os
os
os
osnicicicicicicicicicicicicicicicicicicicicicicick
B
• Figure 16-5  A 23-year-old man with a developmental jaw deformity and malocclusion was referred for surgical evaluation. He
had also recently sustained trauma to the maxillary anterior region that involved a loss of the central incisors. The jaw deformity
was characterized by maxillary deficiency in combination with relative mandibular excess. The patient agreed to a comprehensive
surgical and dental rehabilitative approach. He also had lifelong difficulty breathing through his nose. After periodontal and restorative
evaluations, the patient underwent orthodontic (dental) decompensation. Surgery included maxillary Le Fort I osteotomy in segments
(arch expansion, horizontal advancement, and cant correction); bilateral sagittal split ramus osteotomies (asymmetry correction);
osseous genioplasty (horizontal advancement); and septoplasty and inferior turbinate reduction. In-hospital and initial at-home
convalescence proceeded without difficulty. Three weeks after surgery, increased swelling and tenderness along the right ramus
region were appreciated, and intraoral drainage through the lateral ramus incision was recognized. The patient underwent explora­
tion with Penrose drain placement as an office procedure under local anesthesia, and he was restarted on antibiotics. The drain
was removed 1 week later, and the 10-day course of oral antibiotics was completed. Healing at all osteotomy sites remained on
track. Five weeks after surgery, the patient returned to a more regular diet and physical activity without delay. The orthodontic
appliances were removed 6 months after surgery. A, Presurgical facial and occlusal views with orthodontics in progress. B, Profile
and lateral cephalometric views before surgery.

485
CHAPTER 16  Complications Associated with Orthognathic Surgery
C
Mandibular
adjustment
Arch expansion
Maxillary advancement
D
E
C, Articulated dental casts that indicate analytic model planning. D, Three week postoperative lateral cepha­
lometric radiograph. E, Three week postoperative Panorex radiograph.
• Figure 16-5, cont’d 
Continued

486 SECTION 2  Planning, Surgical Technique, & Complications
Or
Or
Or
Or
Or
Orththththththththththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gnatathici Su
Su
Su
Surg
r ery
ry
ry; J.C.
C Pos
os
os
os
os
os
os
os
os
os
os
os
os
osnicicicicici k
Or
Or
Or
Or
Or
Or
Or
Or
O hthththththth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
gn
gn
g atatatatatatatatatathicicicicicicici Su
Su
Su
Su
Su
S rg
r ery
ry
ry
ry; J.C. Pos
os
os
os
os
os
o nicicicicick
F
Right facial swelling and intra-oral drainage 3 weeks after surgery
Incision and drainage buccal space abscess/drain in place 3 weeks after surgery
F, Facial and occlusal views 3 weeks after surgery at the time of persistent right
facial swelling and intraoral drainage. The patient underwent exploration and Penrose drain placement.
• Figure 16-5, cont’d 
smokers and 7.0% among non-smokers. The site of infec­
tion was primarily the ramus region followed by the Le Fort
I osteotomy region.
Interestingly, six cases of actinomycosis after orthogna­
thic procedures have been reported.216,293 Ozaki and col­
leagues reported a case of actinomycosis that occurred in
the left submandibular area after SSRO.249 The infection
resolved after 2 months of antibiotic therapy.
during orthognathic surgery.210 The authors found that sur­
gical bur breakage was not uncommon (5 out of 76 patients;
6.6%). They concluded that bur retrieval was not always
advisable, because collateral damage to the hard and soft
tissues may occur in the process. They recommended radio­
graphic confirmation immediately after surgery and then
clinical follow up for at least 1 year to confirm that no
foreign body reaction or infection has occurred (Fig. 16-8).
Risks and Complications Specific
to Sagittal Split Ramus Osteotomies
of the Mandible
Unfavorable Sagittal Split Ramus Osteotomy
When completing an SRO, an unfavorable fracture (i.e., a
“bad split”) can occur.23,42,139,162,206,243,334 The definition of a
bad split varies from clinician to clinician. This author
reserves the term bad split only for those SROs in which the
condyle either remains with the distal segment, thus requir­
ing a separate osteotomy (i.e., third piece), or shatters into
a separate component (i.e., third piece) on its own (Fig.
16-9). Other less than ideal splits may include the follow­
ing: 1) a separate fracture or piece of the buccal plate 2) a
NOTE:  Current literature confirms that, for
orthognathic surgery that includes SSRO, the following
are true: 1) prophylactic antibiotics (preoperative,
intraoperative, and postoperative) reduce infection rates
2) effective wound closure (without occurrence of
dehiscence) will diminish infection rates 3) intraoral
drains placed at the osteotomy site are
counterproductive and 4) the incidence of infection is
higher among smokers.
Instrument Breakage: Foreign-Body Reaction
Manikandban and colleagues reviewed the incidence and
consequence of bur breakage within the surgical wound

487
CHAPTER 16  Complications Associated with Orthognathic Surgery
• Figure 16-6  A 50-year-old man with a short face growth pattern and obstructive sleep apnea underwent orthog­
nathic surgery, including maxillary Le Fort I osteotomy; bilateral sagittal split osteotomies of the mandible; and an
osseous genioplasty. Interpositional allogenic grafting was required in the maxilla and chin regions. At the 2-week
postoperative visit, partial dehiscence of the right mandibular vestibular wound was recognized. The distal superior
aspect of the proximal segment was visualized through the wound. There was minimal associated facial swelling
and no abscess or fluid collection. In the office setting, a rongeur was used to remove the exposed bone, and the
patient was restarted on antibiotics. The wound spontaneously closed over the next 10 days. Healing at the oste­
otomy site remained on track, and there was no long-term sequelae. (Note: If the inferior borders had been more
closely aligned before the bicortical screw fixation, then dehiscence with the loss of the bone fragment may not
have occurred.) A, Intraoral view of the right mandibular vestibular wound at 10 days after surgery with dehiscence
and exposure of the superior aspect of the proximal segment. B, Computed tomography scan demonstrating the
portion of the buccal shelf and the proximal segment that was resected with the rongeur. C, Specimen removed
with a rongeur.
A
B
C
Sequestra of bone
Text continued on p. 498
separate fracture or piece of the lingual plate posterior to
the second molar; or 3) a separate fracture or piece of the
coronoid process. All three of these splits are generally
manageable without alteration of the expected postopera­
tive recovery. When the buccal plate separates from the
proximal segment, the fragment is either removed or addi­
tional plate and screw fixation is used to secure it. When
the lingual plate separates from the distal segment, no addi­
tional fixation is generally required. The lingual bone frag­
ment is either removed or left in place. When the coronoid
process separates from the proximal segment, it is usually
removed to limit the chance of ankylosis during the healing
process.

488 SECTION 2  Planning, Surgical Technique, & Complications
Or
Or
Orththththth
r ogn
gn
gn
gn
gn
gn
gn
g athicicicic Su
Su
S rg
r ery
ry
ry
ry; J.C.
C.
C Pos
os
os
os
os
os
os
os
os
os
osnicick
A
B
Asymmetry
correction
Mandibular counter
clockwise rotation
• Figure 16-7  A 20-year-old college student with an asymmetric mandibular excess growth pattern (Hemi-mandibular elonga­
tion) arrived for surgical evaluation. She had previously undergone orthodontic attempts to neutralize the occlusion without
success. She agreed to a combined orthodontic and surgical approach. With the removal of orthodontic (dental) compensation,
surgery was carried out. The procedures included bilateral sagittal split ramus osteotomies (asymmetry correction) and osseous
genioplasty (horizontal advancement). By 5 weeks after surgery, postoperative swelling had generally subsided. A painless
“lymph node” was palpable in the right submandibular region. It was not fixed to the skin or bone. Three months after surgery,
what appeared to be a localized lymph node became tender with erythema and then with drainage through the skin. Cultures
were carried out and showed no specific growth. An infectious disease consult was obtained, and Gram staining showed
gram-positive rods. The patient was placed on amoxicillin and then Augmentin. The localized infection involved intermittent
drainage but without a connection down to the bone. Four months after surgery, the patient agreed to undergo excision of
the soft-tissue mass with primary closure and the reinstituting of antibiotics. Histopathology was unremarkable, and the cultures
remained negative. The wound healed without complications. A, Facial and occlusal views with orthodontics in progress.
B, Articulated dental casts that indicate analytic model planning.

Or
O thth
r ogn
gn
gn
gn
gn
gn
gn
gn
gn
g atatata hicicic Su
S rg
r ery
ry
ry; J.C.
C.
C Pos
os
os
os
os
os
os
os
os
o nicicick
Or
Or
Or
Or
Or
Or
Or
Or
O ththththththththththththththththth
r ogn
gn
gn
gn
g atathicicic Su
Su
Su
Surg
r ery
ry
ry; J.C.
C.
C.
C. Pos
os
os
os
os
os
os
os
os
os
os
os
os
os
o nicicicicicick
C
D
C, Facial views with smile before and 5 weeks after surgery. D, Lateral cepha­
lometric radiographs before and 5 weeks after surgery. E, Panorex radiographs before and 5 weeks
after surgery.
• Figure 16-7, cont’d 
Continued
E