Khe Hở Môi Và Vòm Miệng: Chẩn Đoán Và Quản Lý Điều Trị (Cleft Lip and Palate)

22
G.H. Sperber and S.M. Sperber
and their fusion (Ding et al. 2004 ; Yu and Ornitz
2011 ) . Insights into this palatogenic network
are illustrated in the disruption of a microRNA,
miR-140 that regulates PDGF signaling and
induces cleft palate in humans (Eberhart et al.
2008 ; Li et al. 2010 ) . Wwp2 has been impli-
cated as a regulatory interactor between Sox9
and Mediator 25 in the transcriptional mecha-
nisms of chondrogenesis in the forming palate
(Nakamura et al. 2011 ) .
Developmental studies indicate that sonic
hedgehog (SHH) signaling is a key factor in the
outgrowth of the palatal shelves that is also stim-
ulated by the activity of FGF10, a growth factor
in the mesenchyme that stimulates a receptor,
FGFR2b, in the surface epithelium. The epithe-
lium, in turn, increases its SHH signaling back to
the mesenchyme (Rice et al. 2004 ) . Exquisite
reciprocal signaling between the palate epithe-
lium and mesenchyme directs palatal shelf growth
and morphogenesis. When the palatal shelves
meet in the midline, the surface periderm of the
medial edge epithelial cells undergoes apoptosis,
and an epithelial-mesenchymal transformation
Fig. 1.16 Coronal sections
of embryos at 7.5 ( top ), 8
( middle ), and 9 ( bottom )
weeks depicting palatal
shelf elevation and fusion
(Reproduced by kind
permission of McGraw-Hill
from Losee and Kirschner
( 2009 ) )

23
1 Embryogenetics of Cleft Lip and Palate
occurs in a complex mechanism (Hay 2005 ) . The
transforming growth factor- b (TGF b ) signaling
pathway, active in the medial edge epithelium,
participates in the fusion of the palatal shelves
and promotes the epithelial-mesenchymal trans-
formation during palatal fusion (Bush and Jiang
2012 ; Fitzpatrick et al. 1990 ; Greene and Pisano
2010 ; Iordanskaia and Nawshad 2011 ; Ito et al.
2003 ; Iwata et al. 2011 ; Xiong et al. 2009 ;
Nakajima et al. 2010 ; Iseki 2011 ) .
a
b
c
d
Fig. 1.17 ( a ) View of right half of a 6-week-old human
embryo showing early vertical palatal shelf and lip form-
ing from the maxillary prominence; short arrow, site of
primary palate; long arrow, posterior edge of secondary
palate (SEM ×30). ( b ) Palatal shelves of a 7-week-old
human embryo showing anterior end of right shelf ( a )
becoming horizontal, while the posterior end ( b ) remains
vertical (SEM ×11). ( c ) Palatal shelves of an 8-week-old
human embryo showing the horizontal shelves approach-
ing each other and the anterior primary palate ( arrow )
(SEM ×11). ( d ) The nearly fused palatal shelves of a
9-week-old human fetus. The soft palate region ( arrowed )
is still unfused (SEM ×8) (Scanning electron micrographs
from Shaw et al. ( 1978 ) . By permission; Reproduced by
kind permission of McGraw-Hill from Losee and
Kirschner ( 2009 ) )

24
G.H. Sperber and S.M. Sperber
The medial edge epithelium of the palatal
shelves is of particular signi fi cance in establish-
ing fusion. There exists a genetic heterogeneity
along the anterior-posterior and medial-lateral
axes of the developing palate. Different regula-
tory mechanisms exist for the fusion of the ante-
rior versus the posterior region of the palate. The
boundary between the anterior and posterior
regions of the palate is de fi ned by the most poste-
rior of the four palatal rugae, composed of regu-
larly spaced transverse ridges of epithelial
thickenings underlain by mesenchyme (Pantalacci
et al. 2008 ; Welsh and O’Brien 2009 ) . The rugae
are stripes of sonic hedgehog (SHH) expression
that are interspersed by inhibiting fi broblast
growth factor (FGF) expression, re fl ecting an
activator-inhibitory pair indicating a Turing-type
reaction–diffusion spacing mechanism (Sohn
et al. 2011 ; Economou et al. 2012 ) . These rugae
contain a variety of sensory cells (Nunzi et al.
2004 ) and cranial neural crest stem cells (Widera
et al. 2009 ) . Multiple genes (Msx1, Bmp4, Bmp2,
Fgf10, and Shox2) show restricted expression in
the anterior region of the palate (Bush and Jiang
2012 ; Hilliard et al. 2005 ) . FGFR2 is expressed
in the epithelium and mesenchyme of the middle
and posterior palate (Porntaveetus et al. 2010 ) .
FGF8 induces Pax9 expression in the posterior
region of the palatal mesenchyme (Iwata et al.
2011 ; Snyder-Warwick et al. 2012 ) . The epithe-
lial-mesenchymal transition of the epithelial
layers on opposing shelves requires transforming
growth factor- b 3 (TGF b 3) as the most prominent
inducer and ephrin-mediated signaling to promote
mesenchyme proliferation and fusion (San
Miguel et al. 2011 ) . Programmed cell death
(apoptosis) of the epithelial layers is induced by
the Fas ligand (FasL)-Fas-caspase extrinsic
apoptosis pathway to allow fusion to occur
(Huang et al. 2011 ) . The fusion seam initially
forms anteriorly in the region of the hard palate,
proceeding both rostrally and caudally to
complete merging in the soft palate region. The
most posterior of the rugae de fi nes the boundary
between the hard and soft palates. A combination
of apoptotic surface epithelial cells and a surface
coat of glycoproteins and desmosomes facilitate
epithelial adherence between the contacting pala-
tal shelves (Cuervo and Covarrubias 2004 ) .
Disintegration of the seam is facilitated by
changes in protein content, cell migration and
apoptosis (Vukojevik et al. 2012 ) .
Epithelial-mesenchymal transformation of the
underlying basal epithelial cells may be a factor
for mesenchymal coalescence of the shelves
(Vaziri Sani et al. 2005 ) . Exquisite control of the
program is illustrated by a dosage-dependent role
for Spry2, an antagonist of FGF signaling, that
participates in the modulation of the growth and
patterning of palate development (Welsh et al.
2007 ) . During palate closure, the mandible
becomes more prognathic and the vertical
dimension of the stomodeal chamber increases,
but the lateral maxillary width remains stable,
allowing shelf contacts to occur. Elongation of
the hard palate and the sequential addition of
rugae, in mouse models, are induced by Wnt- b -
catenin signaling (Lin et al. 2011 ; Pantalacci
et al. 2008 ) . Failure of glycoprotein adhesiveness
and transformation of epithelial cells into mesen-
chyme, allowing epithelial persistence, are factors
contributing to palatal clefting.
1.5.1 Ossi fi cation
Intramembranous ossi fi cation of the palate com-
mences in the 8th week postconception from
de novo ossi fi cation and centers initially separate
from primary ossi fi cation centers in the maxillae.
The palatine bones ossify separately and with the
palatal centers spread centrifugally to create the
hard palate. A number of genes are activated dur-
ing osteogenesis (Shh, Ihh, Ptc1, Gli1-3, Runx2,
Alp, Bmpr1, Col1a1, and GSK-3 b ) (Baek et al.
2011 ; Levi et al. 2011 ; Nelson et al. 2011 ) .
Premaxillary ossi fi cation sites appear transiently
in the primary palate region but fuse with the
maxillary ossi fi cation centers by the end of the
third fetal month, losing their separate identity.
These primary palate ossi fi cation sites persist in
nonhuman primates, leading to premaxillary
bones that do not exist in humans. The interven-
ing sagittal midpalatal and the coronal transverse
maxillopalatine sutures designate the different
bones of the palate. The midpalatal suture is a site

25
1 Embryogenetics of Cleft Lip and Palate
exploited by orthodontists by widening for rapid
maxillary expansion in cases of narrow palates
that cause dental crowding. Defective bone for-
mation, after proper fusion of the palatal shelves,
results in submucous cleft palate, a frequent
clinical anomaly.
Ossi fi cation does not occur in the most poste-
rior part of the palate, giving rise to the region of
the soft palate. Myogenic mesenchymal tissue of
the fi rst and fourth pharyngeal arches migrates
into this faucial region, supplying the muscula-
ture of the soft palate and fauces. The tensor veli
palatini is derived from the fi rst arch (trigeminal
nerve), and the levator palatini, uvular, and fau-
cial pillar muscles are derived from the fourth
arch (vagus nerve) (Fig. 1.18 ).
1.5.2 Palatoschisis
If I do not remember thee, let my tongue cleave to
my palate. Psalm 137:6
Failure of fusion of the palatal shelves on either
side of the midline results in cleft palate. Palatal
clefting may be syndromic, that is, associated
with other developmental anomalies, or nonsyn-
dromic, with no other developmental anoma-
lies. These clinical designations do not provide
understanding of the intrinsic causes of clefting.
The complexity of palatogenesis accounts for
the relatively common occurrence of its failure,
resulting in clefting. The vulnerability of the
palate to clefting is indicative of its relatively
recent evolution and is susceptible to a variety
of environmental impacts acting on a back-
ground of genetic predispositions to clefting
(Yuan et al. 2011 ) .
Clefting of the palate is a consequence of sev-
eral factors impeding the closure and fusion of
the three palatal elements. They include absence
or de fi ciency of the tongue-depressing hyoglos-
sus muscle, a Hoxa2 gene loss-of-function effect
seen in mouse models, allowing continued imped-
ance of shelf elevation by the tongue (Barrow and
Capecchi 1999 ) . The tongue normally fl attens but
remains highly arched in cleft palate cases. Notch
signaling that includes the Notch family of recep-
tors and the delta-like and jagged ligands are nec-
essary for palatal fusion. Homozygous knockout
mice for Jagged2 exhibit palate-tongue fusions
(Jiang et al. 1998 ; Xu et al. 2010 ) . Failure of pal-
atal shelf elevation has been attributed to a num-
ber of other genetic mutations characterized in
mice notably de fi cient for Fgf10 , Pax9 , and Msx1
(Alappat et al. 2005 ; Peters et al. 1998 ; Zhang
et al. 2002 ) .
Even having elevated, the persistence of the
epithelial seam between the shelves creates con-
ditions for clefting and leave remnants of epi-
thelial “pearls” that may become cysts. The
Fig. 1.18 Palate and upper
lip of a 22-week-old fetus.
Note the developing rugae in
the hard palate and the
extensive soft palate
posteriorly. F frenum, P
palate, PR palatal rugae, SP
soft palate (Reproduced by
kind permission of McGraw-
Hill from Losee and
Kirschner ( 2009 ) )

26
G.H. Sperber and S.M. Sperber
complex interactions of numerous genes, tran-
scription factors, and signaling transductions are
being revealed in several recent reports on the
phenomena of palatogenesis and palatoschisis
(Figs. 1.19 and 1.20 ) (Lan et al. 2004 ; Letra et al.
2011 ; Liu et al. 2005 ; Rice et al. 2004 ; Sasaki
et
al.
2004 ;
Stanier
and
Moore
2004 ;
Yu et al. 2005 ) . Disruption of the differentiation
and adhesion competence of the medial edge epi-
thelium, even with apposition of the palatal shelf
antimeres, can result in clefting of the palate.
The shape of the cleft in the palate is indicative
of its etiology. V-shaped clefts are the conse-
quence of inadequate tissues in the shelves to
complete closure. U-shaped clefts are usually
associated with micrognathia and glossoptosis
(Robin-type clefts) resulting from the tongue
obtruding between the shelves, preventing their
elevations (Hanson and Smith 1975 ) . A genetic
contribution to Pierre Robin sequence resulting in
a cleft palate is shown in the perturbation of the
FAF1 gene, an enhancer of apoptosis expressed in
the pharyngeal arches and necessary for cranial
neural
crest
differentiation
into
cartilage
(Ghassibe-Sabbagh et al. 2011 ) .
The least severe form of cleft palate is the bi fi d
uvula, of relatively common occurrence and sel-
dom clinically signi fi cant. Increasingly severe
FGF9
FGF10
FGFR2
RUNX2
SHH
IRF6
PDGFa
Pax9
Fig. 1.19 Midcoronal sections of an 8-week-old human
embryo upon which are depicted the gene expression
patterns derived from mouse embryos (Reproduced by
kind permission of McGraw-Hill from Losee and
Kirschner ( 2009 ) )

27
1 Embryogenetics of Cleft Lip and Palate
clefts always incur posterior involvement, the cleft
advancing anteriorly in contradistinction to the
direction of normal fusion (Fig. 1.21 ). De fi cient
fusion posterior to the incisive foramen derive
from the secondary rather than the primary palate,
whereas anterior clefts incur primary palate
de fi ciencies. Secondary postfusion clefting of the
palate may develop prenatally as a confounding
etiological phenomenon (Arnold et al. 1998 ) .
Clefts may be submucous in nature, involving
muscle discontinuity, yet with an intact overlying
mucosa.
The consequences of palatal clefting are mul-
tifarious, ranging from oronasal food regurgita-
tion, speech impediments, dental malocclusion,
facial growth impedance, and social isolation.
IRF6
LHX8
RUNX1
TGF-β3
Fig. 1.20 Midpalatal fusion
gene expression patterns
derived from mouse embryos
(Reproduced by kind
permission of McGraw-Hill
from Losee and Kirschner
( 2009 ) )
Upper lip
Vestibule
Alveolar
process
Cleft palate variations
a
b
c
Fig. 1.21 Schematic
depiction of degrees of palatal
clefting. ( a ) Bi fi d uvula. ( b )
Unilateral cleft palate and lip.
( c ) Bilateral cleft palate and
lip (Reproduced by kind
permission of McGraw-Hill
from Losee and Kirschner
( 2009 ) )

28
G.H. Sperber and S.M. Sperber
Conclusion
The preceding insights into orofacial devel-
opment provide clinicians with a rationale
for understanding the occurrence of clefts as
deviations of normal morphogenesis. With
the advent of identi fi cation of chromosomes,
genes, and growth factors responsible for
development of the orognathofacial complex,
clinical geneticists, speech pathologists, and
surgeons are in a better position to predict,
prognose, and diagnose clefts of the face, lips,
and palate. The anticipation of biomimetic
intervention by genetic engineering and molec-
ular growth factors in producing scarless heal-
ing of cleft surgical repair is becoming ever
more realistic (Larson et al. 2010 ) . The current
explosion of molecular biology encompassing
genomics, proteomics, metabolomics, and
pharmacogenomics for targeted drug therapy
will have a profound impact upon the prognos-
tication, treatment modalities, and prevention
of labiopalatal clefting. The rapid advances in
our understanding of cellular behavior during
embryonic development leading to differentia-
tion and morphogenesis provide opportunities
to exploit this knowledge in preventive, cura-
tive, and regenerative healing applications.
The current cornucopia of cognitive diagnos-
tic capabilities provided by genetics, immu-
nohistochemistry, cloud computer networks,
obstetrical ultrasonography, CAT scanning,
nuclear magnetic resonance (NMR) scanning,
3D computer stereology, next-generation
sequencing technology, high-throughput gene
expression pro fi ling, and mass spectrometry
provide the potential for prenatal diagnosis
and possible therapy of palatofacial clefting.
Nonetheless, much remains to be done for
these techniques to be translated into clinical
practice and is the central challenge of labora-
tory bench to bedside transition technology.
1.6
Websites
1.
2.
3.
4.
5.
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35
S. Berkowitz (ed.), Cleft Lip and Palate,
DOI 10.1007/978-3-642-30770-6_2, © Springer-Verlag Berlin Heidelberg 2013
2
After 40 years of treating children with various
types of clefts, this author has concluded that
the success or failure of a surgical procedure
depends on the degree of palatal cleft defect at
the time of surgery and the resulting facial
growth pattern as well as the surgical skills
and the surgical procedure utilized. This con-
clusion will not be new to the experienced
orthodontist who in all probability recognizes
that the progress recorded in treatment depends,
for the most part on the skeletal and facial
growth patterns inherent in the patient and the
interaction of surgery with facial and palatal
growth.
2.1
Serial Cephaloradiographs
and Casts of the Maxillary and
Mandibular Dentition
and Occlusion
To properly assess the results of treatment, there
is a fundamental need for serial casts, lateral
cephalometric fi lms, and photographs in individ-
ual case reports.
Pruzansky ( 1953, 1955 ) often stated that it is
unfortunate that plastic surgeons’ training in the
realm of clefts and their variations tends to be
totally inadequate because their fi rst encounters
with patients usually occur in the clinic or operat-
ing room. Furthermore, there is seldom recourse
to anatomical specimens to better appreciate the
nature of the cleft deformity. The trainee is depen-
dent on the empirical experience of his preceptor
for knowledge of the natural history of the defect
and long-term response to therapy. In most cases,
other than before and after facial photographs,
there are no objective records to determine why
the outcome was a success or failure.
The collected serial data to be shown in this text
will provide the clinician in training with an over-
view of the variations that can be encountered in
each cleft type, the signi fi cance of genotype differ-
ences that in fl uence growth and response to sur-
gery, and the natural history of each cleft entity.
Over the years certain cephalometric mea-
surements have become standardized and have
The Value of Longitudinal Facial
and Dental Casts Records in Clinical
Research and Treatment Analysis
Samuel Berkowitz
S. Berkowitz , DDS, M.S., FICD
Adjunct Professor,
Department of Orthodontics ,
College of Dentistry, University of Illinois ,
Chicago , IL , USA
Clinical Professor of Surgery and Pediatrics (Ret),
Director of Research (Ret),
South Florida Cleft Palate Clinic,
University of Miami School of Medicine ,
Miami , FL , USA
Consultant (Ret),
Craniofacial Anomalies Program ,
Miami Children’s Hospital ,
Miami , FL , USA
e-mail: sberk3140@aol.com

36
S. Berkowitz
been applied to selected population samples to
develop statistical means or averages. In the treat-
ment of cleft lip and/or palate, this approach has
provided useful data in studying morphologic
growth changes in the head, evaluating dentofa-
cial abnormalities, and assessing responses to
surgical and orthodontic treatment. The data has
been particularly useful in determining the tim-
ing and type of procedure selected to treat indi-
vidual problems. The measurements and analyses
utilized are primarily pro fi le-oriented and reveal
both anteroposterior and vertical relationships of
the various parts of the dentofacial complex.
To assess changes during the course of general
growth and treatment, head radiographs of the
same individual taken at separate times are traced
and the tracings superimposed to ascertain the
changes that have occurred. A common method is
to register the two tracings at the point sella with
the sella-nasion lines superimposed (Fig. 2.2a , b ).
This method provides a gross overview of changes
in the dentofacial complex and in soft tissue but is
useful only in evaluating what has already
occurred. In this text, we also use the Coben
superimposition procedure (basion horizontal)
because it more accurately re fl ects actual cranio-
facial growth direction (Figs. 2.1d and 2.2c ).
The use of “landmark,” or baseline, images
associated with the basicranium to show the com-
posite results of facial growth can provide mean-
ingful information because it is the enlargement
of the face relative to the cranial base that is being
evaluated. In the child, further growth changes in
the anterior part of the cranial base slow consid-
erably at about 5–6 years of age, whereas facial
growth continues actively through adolescence or
beyond. Comparing the relative growth between
these two regions, rather than simply focusing on
a single fi xed point, provides clinically useful
information when cephalometrically evaluated.

37
2 The Value of Longitudinal Facial and Dental Casts Records in Clinical Research and Treatment Analysis
Fig. 2.1 ( a – d ) Various methods used to demonstrate
facial changes using lateral cephalometrics. ( a ) Facial
angles. These are just a few of the angles which describe
changes in the skeletal pro fi le. There are many more
angles and linear measurements which can be used to
relate the maxilla to the mandible and both jaws to the
cranial base. ( b ) Facial polygon. This is a graphic method
used to describe the boundaries of the skeletal face.
(Pogonion constructed, Po’, is the same point as gna-
thion.) Facial growth changes can be shown by superim-
posing each succeeding polygon on the anterior cranial
base ( SN ) and registering on sella turcica ( S ). ( c ) Projecting
facial landmarks to a constructed Frankfort horizontal line
which is arbitrarily drawn 6° off the SN line. This angle
can vary with steepness of the anterior cranial base. This
graphic method will show the relative contribution of
various structures within the maxilla and the mandible to
the pro fi le. ( d ) Basion horizontal created facial polygon
(Coben 1986 ) . This method of superimposing tracings
graphically re fl ects his overall concept of fi xed growth.
A plane at the level of the anterior border of foramen mag-
num (basion) parallel to Frankfort horizontal where
Basion is the point of reference for the analyses of cranio-
facial growth
a
b
c
d

38
S. Berkowitz
Fig. 2.2 ( a ) Case CP #127 (CPCLP). Superimposed
facial polygons from 1 month, 18 days of age to 7 years,
8 months, and 12 days of age. A result of the mandible’s
downward growth increments exceeding its horizontal
growth increments, this is an example of “poor” facial
growth in that the pro fi le fails to fl atten as the mandible
remains retrognathic. Note that in this and the following
illustration, the forward projection of the premaxilla does
not increase after 1 year, 2 months, and 22 days

39
2 The Value of Longitudinal Facial and Dental Casts Records in Clinical Research and Treatment Analysis
C P C #127
GONION
SELLA
PTM
POGONION
MAXILLA
NASION
PREMAXILLA
0-1-18
0-5-12
0-9-0
1-2-22
1-7-26
2-1-15
2-11-4
3-5-23
4-5-23
5-0-2
6-5-3
7-8-12
S
Go
Po
M
N
Ptm
b
Fig. 2.2 (continued) ( b ) Case CP
#127. Projecting facial landmarks to
a constructed Frankfort horizontal
6° off the SN line. Although each of
the skeletal structures except for the
mandible has increased in size, the
relative position of midfacial
structures to the anterior cranial
base has remained relatively stable

40
S. Berkowitz
2.2
The Beginning of Longitudinal
Cleft: Palate Research Studies
Two major research problems were common in
cleft palate surgical studies prior to the 1950s.
Pruzansky ( 1953, 1955 ) commented on the sur-
geon’s tendency to group all types of clefts
together in research and clinical treatment. He
also stated that surgeons were limited in their
study of pathologic anatomy of clefts due to the
unavailability of serial dental casts, cephalora-
diographs, and photographic records.
The need for clinical records was apparent to
many researchers, and within a decade, many ret-
rospective clinical data sets were developed.
These data sets spawned many investigators to
determine the long-term in fl uences of surgical
and neonatal maxillary orthopedic procedures on
palatal and facial growth and development. As a
result of these early studies, useful diagnostic and
prognostic information was obtained that pro-
vided a rationale for the management of individ-
ual cleft cases. These clinical records offered an
accurate means for measuring and recording indi-
vidual variation and for plotting the progress of
each case in terms of growth and response to var-
ious treatments. As a result of these fi ndings, the
quality of care improved, resulting in more aes-
thetic and functional outcomes. Proper documen-
tation, using objective records and individual
treatment outcomes, has extended to many more
modi fi cations where it is possible to perform
multicenter retrospective studies.
2.3
Research Methods (Atkins 1966 ;
Byse et al. 1983 )
2.3.1 Retrospective Studies
In a retrospective study, the nature of the study
group must be delineated precisely. De fi nite cri-
teria should be established so that there is no
Fig. 2.2 (continued) ( c ) Case CP #127.
Basion horizontal coordinate computer
craniofacial serial tracings at ages 8, 13, and
18 years. Tracings are registered at Basion and
oriented in Frankfort horizontal. Serial tracings
maintain a constant S-N/FH relationship. S-N
and FH planes are parallel. Tracings depict
Coben’s growth philosophy, which states that
craniofacial growth is re fl ected away from the
foramen magnum (basion) and the vertebral
column (Reprinted from Coben ( 1986 ) )

41
2 The Value of Longitudinal Facial and Dental Casts Records in Clinical Research and Treatment Analysis
ambiguity about types of cases and stages of
growth development to be included in, or excluded
from, the study. The choice of the case and con-
trol groups should be guided by concerns of
validity. The advantages of retrospective studies
are that they can be conducted relatively rapidly
because the records of patients whose treatment
is already complete can be used. The investigator
is protected against the circumstance of “subject
dropout” during the course of treatment, and they
are relatively economical.
2.3.2 Prospective Studies
The advantages and disadvantages of prospective
studies are in essence the inverse of those of ret-
rospective studies. Provided that ethically and
logistically satisfactory plans for random assign-
ment to treatment can be developed, prospective
trials afford an opportunity to control selection
bias and to de fi ne and control the records acquisi-
tion process.
The main disadvantages of prospective trials
are that they are expensive and a great deal of
time must inevitably elapse between project ini-
tiation and the point at which data on most of the
main outcome variables become available for
analysis.
Multicenter comparisons of surgical orthodon-
tic treatment outcomes are an ef fi cient way of
testing the effectiveness of various treatment phi-
losophies and surgical techniques. Differences
among surgeons, variances in performance by the
same surgeon over the years, and differences in
techniques are dif fi cult to identify and compare
in isolation. However, in multicenter clinical
studies, differences in clinical procedures among
operators can, within de fi ned limits, be compared
and evaluated successfully without arousing
criticism.
2.3.3 Clinical Trials
A clinical trial may be de fi ned as a carefully
designed prospective study that attempts to
answer a precisely de fi ned set of questions with
respect to the effects of a particular treatment.
A clinical trial is a major undertaking which
requires considerable money, personnel, facilities,
time, and effort.
The simplest design for a clinical trial involves
randomization between two different surgical
treatment regimens to answer one speci fi c ques-
tion; for example, which of two surgical proce-
dures is the most bene fi cial. To add a larger
number of surgical procedures makes the trials
more dif fi cult to manage.
There are two reasons for not using a random-
ized clinical trial (RCT) method for surgical eval-
uation of cleft closure procedures whether done as
a multicenter or single-center trial. The fi rst is the
need for the surgeon to disregard the unique nature
of the individual cleft defect and perform a stan-
dard surgical treatment being tested, the presump-
tion being that clefts of all sizes and shapes will
react the same way to the same surgical proce-
dure. The second reason concerns the ethical
questions involving the sequencing of surgical
procedures and the use of the surgeon’s skills.
2.3.3.1 Randomization of Surgical
Procedures
In proposed multicenter RCT, it is expected that
each surgeon will randomly utilize various surgi-
cal procedures sequentially for each type of cleft
to determine the relative differences in outcome
between procedures.
With the present restraints on certain types of
human research, Human Subject Research Review
Committees in most settings would be reluctant to
permit the use of various elective surgical proce-
dures in a research setting if there is a possibility
that a surgical procedure might lead to facial
dis fi gurement. Most surgeons would reject par-
ticipating in a study employing a particular proce-
dure they already have used and found to be
inadequate. Many surgeons see the choice and
timing of cleft surgical procedures as varying with
the geometric characteristics of the palatal defect;
therefore, the concept of randomization cannot be
considered as an alternative to what they are
already doing. The factor of surgical skill in a ran-
domized trial must be considered as a variable in
determining the effectiveness of a procedure. Can

42
S. Berkowitz
all participating surgeons be equally skilled in all
procedures?
2.3.3.2 The Ethics of Surgical
Retrospective Clinical Trials (RCT)
It is impossible to disassociate scienti fi c from ethi-
cal considerations when dealing with cleft palate
research (Gifford 1986 ; Hellman and Hellman
1991 ; Israel 1978 ; Kukafka 1989 ) . Different
research protocols and evaluation methods carry
different ethical problems, the more so when life
or death issues are not being considered.
2.3.3.3 Informed Consent
When a patient is deemed appropriate for a par-
ticular clinical trial, a fi rst step is often to obtain
informed consent. This is a legal requirement in
the USA, but not in all countries. In some European
countries, each participating hospital decides on
whether and how to handle informed consent.
Informed consent is a social construct based
on ethical guidelines and supported by legal prec-
edents. In order for consent to be legally valid, it
must be obtained voluntarily from a mentally
competent person of legal age.
The greater the seriousness of the potential
injury, even if the risk is minimal, the greater the
obligation to inform the patient (or parent).
The greater the chance of a risk occurring, even if
the injury would be minimal, the greater the obli-
gation to inform the patient (parent). The more
elective the proposed treatment, the more serious
injury will be perceived.
Sheldon Baumrind ( 1993 ) , summarizing the
role of clinical research in orthodontics which is
also applicable to cleft palate research, states:
Cogent arguments can be made concerning the eth-
ics of conducting structured clinical experiments in
the kinds of long-term therapeutic situations which
interest orthodontists. One telling argument is that
since therapists have an absolute and transcendent
obligation as professionals to deliver for each patient
the treatment which they believe best for that patient,
no subject can ethically be randomized to one of two
possible treatments unless there is true uncertainty
as to which of the two treatments is in the patient’s
best interest. For the same reason any experimental
design that asks a clinician to treat a patient against
the clinician’s own professional bias is inappropri-
ate at best. And even if ethical reservations could be
overcome, it would clearly be of only minimal
scienti fi c value to accumulate data on how patients
fare under treatments not considered optimal at the
time they are delivered.
Baumrind ( 1993 ) concludes:
Except in special and very limited circumstances,
clinical studies in orthodontics cannot and should
not be expected to reveal categorically which of
two or more treatments is better in a global sense.
They can and should be expected to supply valid
and reliable information about the mean effects of
different treatments. But more important, they
should supply information about the usual indi-
vidual variability of human growth, development,
and response to therapeutic intervention.
Retrospective studies have permitted clinical
investigators to evaluate the palatal and facial
growth and development responses within a par-
ticular cleft type according to the type and timing
of the surgical procedures employed. Such stud-
ies have shown that the degree of palatal scarring
is directly related to the areas of denuded bone
resulting from the displacement of the palates
mucoperiosteum during cleft closure.
Roentgencephalometry has aided in the elucida-
tion of the nature of the craniofacial malformation
associated with facial clefts as it affects the mandi-
ble, maxilla, orbits, nasopharyngeal area, and the
base of the skull and cervical vertebrae. Moreover,
current studies on the variable growth and involu-
tion of tonsils and adenoids have raised a number
of questions of interest to immunologists.
2.4
The Need for Geometric and
Quantitative Analysis of Cleft
Palate Casts
Treatment planning in cleft lip and palate habili-
tation is contingent upon understanding the natu-
ral history of the palatal cleft defect and the face
in which it exists. Longitudinal dental cast stud-
ies ultimately helped explain many cause and
effect relationships which existed between pala-
tal surgery and subsequent facial development.
However, there still remains an important need
for our understanding of palatal development,
which will further re fi ne and improve rehabilita-
tive procedures. The purpose is to consider previ-

43
2 The Value of Longitudinal Facial and Dental Casts Records in Clinical Research and Treatment Analysis
ously posed questions in light of newer
biostereometric techniques. Specially, the fol-
lowing questions have been asked:
1. Are the palatal shelves intrinsically de fi cient,
adequate, or excessive in mass?
2. To what extent does the geometric relation-
ship of the palatal shelves in one cleft compare
with that of another in the same type of cleft?
With other types of clefts? With normal
palates?
3. To what extent are the palatal shelves dis-
placed in space?
4. How are these parameters altered as a conse-
quence of growth and surgical reconstruction?
The advent of advanced biostereometric tech-
nique and 3D digital cameras with computer
made it possible to analyze the size and shape
of the palate in greater detail through intensive
geometric survey. The data collected by these
systems can be reduced to a mathematical for-
mat and subjected to analysis by high-speed
computers.
In accordance with these objectives, we under-
took a series of phased studies utilizing stereo-
photogrammetric electromechanical 3D digital
analysis of serial casts of infants with cleft lip
and palate with the following speci fi c aims:
1. Test the reliability of the method for selecting
the proper anatomical landmarks when extrap-
olating data from the stereophotographs.
2. Compare and contrast 2D and 3D surface area
measurements with other descriptive measure-
ments to determine if there are signi fi cant dif-
ferences in their interpretive values.
3. Perform 3D analysis of serial casts in order to
describe the changing geometry of the palatal
vault in mathematical terms.
4. Determine whether the descriptive analysis
revealed additional information relative to the
geometric changes that follow in the course of
time.
5. Determine by differential analysis if a con-
stant geometrical relationship might exist
between the size and shape of the lesser to
greater palatal segment in a complete unilat-
eral cleft lip and palate.
6. The best time to determine palatal surgery
based on the size of the cleft relative to the
size of the body palate.
References
Atkins H (1966) Conduct of a controlled clinical trial. Br
Med J 2(5510):377
Baumrind S (1993) The role of clinical research in ortho-
dontics. Angle Orthod 63:235–240
Byse ME, Stagust MJ, Sylvester RJ (eds) (1983) Cancer
clinical trials – methods and practice. Oxford
University Press, London
Coben SE (1986) Basion horizontal – an integrated concept
of craniofacial growth and cephalometric analyses.
Computer Cephalometrics Associated, Jenkintown
Gifford F (1986) The con fl ict between randomized clini-
cal trials and the therapeutic obligation. J Med Philos
11:347–366
Hellman S, Hellman DS (1991) Of mice but not men:
problems of the randomized clinical trial. N Engl
J Med 324:1585–1589
Israel L (1978) Practical and conceptual limitations of
best conceived randomized trials. Biomedicine
28(Special issue):36–39
Kukafka AL (1989) Informed consent in law and medi-
cine: autonomy vs. paternalism. J Law Ethics Dent
2:132–142
Pruzansky S (1953) Description, classi fi cation, and analy-
sis of unoperated clefts of the lip and palate. Am
J Orthod 39:590
Pruzansky S (1955) Factors determining arch form in
clefts of the lip and palate. Am J Orthod 41:827

45
S. Berkowitz (ed.), Cleft Lip and Palate,
DOI 10.1007/978-3-642-30770-6_3, © Springer-Verlag Berlin Heidelberg 2013
3
3.1
Maxillary and Mandibular
Growth Concepts
It is not the author’s intent to write a de fi nitive
treatise on facial growth and its control processes
because there are better sources for such informa-
tion. However, because the history of cleft palate
treatment has been in fl uenced by what clinicians
think is the correct facial growth process, it
behooves the author to support or refute the vari-
ous facial–palatal growth concepts based on his
own clinical fi ndings.
3.1.1 Newborn Palate with
a Cleft of the Lip or Palate
Is bone missing, adequate, or in excess? What is
the geometric palatal relation of the palatal seg-
ments at birth? With complete clefts of the lip
and palate, are the palatal segments collapsed or
expanded? Can the palatal segments be stimu-
lated to develop to a larger size by neonatal ortho-
pedic appliances? A number of studies have
attempted to determine whether the cleft palate
was de fi cient or adequate in osteogenic tissue;
unfortunately, the investigators were limited by
paucity of data, lack of homogeneity in their
samples and the hazards of estimating growth
from cross-sectional data.
3.1.2 Genetic Control Theory:
Craniofacial Growth Is Entirely
Predetermined
Enlow ( 1975 ) writes that, in the past, it was
thought that all bones having cartilage growth
plates were regulated entirely and directly by the
intrinsic genetic programming within the carti-
lage cells. Intramembranous bone (maxillary)
growth, however, was believed to have a different
source of control. This type of osteogenic process
is particularly sensitive to biomechanical stresses
and strains, and it responds to tensions and pres-
sure by either bone deposition or resorption.
Tension, as traditionally believed, speci fi cally
induces bone formation. According to the tradi-
tional wisdom, when tension is placed on a bone,
the bone grows locally in response. Pressure, on
the other hand, if it exceeds a relatively sensitive
threshold limit, speci fi cally triggers resorption.
According to this theory when muscle and over-
all body growth are complete, the bone attains
Facial and Palatal Growth
Samuel Berkowitz
S. Berkowitz , DDS, M.S., FICD
Adjunct Professor, Department of Orthodontics ,
College of Dentistry, University of Illinois ,
Chicago , IL , USA
Clinical Professor of Surgery and Pediatrics (Ret),
Director of Research (Ret),
South Florida Cleft Palate Clinic,
University of Miami School of Medicine ,
Miami , FL , USA
Consultant (Ret), Craniofacial Anomalies Program ,
Miami Children’s Hospital , Miami , FL , USA
e-mail: sberk3140@aol.com

46
S. Berkowitz
biomechanical equilibrium; that is, the forces of
the muscles are then in balance with the physical
properties of the bone. This turns off osteoblastic
activity, and skeletal growth ceases.
Unfortunately for traditional schools of
thought, growth control in the human body is
more complex than this. Moreover, it is now
known that there is not a direct, one-to-one cor-
relation
between
tension–deposition
and
pressure–resorption.
3.1.3 Functional Matrix Theory (Moss
1962, 1969 ) (Figs. 3.1 and 3.2 )
Enlow ( 1975 ) goes on to explain that, with the
development of the functional matrix principle, a
number of important hypotheses began to receive
attention. One of these is that the “bone” does not
regulate its own growth. The genetic and epige-
netic determinants of skeletal developments are
in the functional tissue matrix, that is, muscle,
nerve, glands, teeth, neurocranial fossa, and
nasal, orbital, oral, and pharyngeal cavities. This
is primary while the growth of the skeletal unit is
secondary. However, although the functional
matrix principle describes what happens during
growth, it does not account for how it happens.
Experiments have shown that mechanical forces
are not the principal factor controlling bone
growth.
Most researchers agree that a notable advance
was made with the development of the functional
matrix principle introduced by Moss ( 1962,
1969 ) . It deals with what determines bone and
cartilage growth in general. The concept states, in
brief, that any given bone grows in response to
functional relationships established by the sum of
all the soft tissues operating in association with
that bone. This means that the bone itself does
not regulate the rate and direction of its own
growth; the functional soft tissue matrix is the
actual governing determinant of the skeletal
growth process.
The course and extent of bone growth are sec-
ondarily dependent on the growth of pace-mak-
ing soft tissues. Of course, the bone and any
cartilage present are also involved in the opera-
Fig. 3.1 The process of new bone deposition does not
cause displacement by pushing against the articular con-
tact surface of another bone. Rather, the bone is carried
away by the expansive force of all the growing soft tissues
surrounding it. As this takes place, new bone is added
immediately onto the contact surface, and the two separate
bones thereby remain in constant articular junction. The
nasomaxillary complex, for example, is in contact with
fl oor of the cranium ( top ). The whole maxillary region is
displaced downward and forward away from the cranium
by the expansive growth of the soft tissues in the midfacial
region ( center ). This then triggers new bone growth at the
various sutural contact surfaces between the nasomaxillary
composite and the cranial fl oor ( bottom ). Displacement
thus proceeds downward and forward as growth by bone
deposition simultaneously takes place in an opposite
upward and backward direction (i.e., toward its contact
with the cranial fl oor) (From Enlow ( 1975 ) )

47
3 Facial and Palatal Growth
tion of the functional matrix, because they give
essential feedback information to the soft tissues.
This causes the soft tissues to inhibit or acceler-
ate the rate and amount of subsequent bone
growth, depending on the status of the functional
and mechanical equilibrium between the bone
and its soft tissue matrix. The genetic determi-
nants of the growth process reside wholly in the
soft tissues and not in the hard part of the bone
itself.
The functional matrix concept is fundamental
to an understanding of the overall process of bone
growth control. This concept has had a great
impact in the fi eld of facial biology. The concept
also comes into play as a source for the mechani-
cal force that carries out the process of displace-
ment. According to this now widely accepted
explanation, the facial bones grow in a subordi-
nate relationship with all the surrounding soft tis-
sues. As the tissues continue to grow, the bones
are passively (i.e., not of their own doing) carried
along (displaced) with the soft tissues attached to
the bones by Sharpey’s fi bers. Thus, for the naso-
maxillary complex, the expansion of the facial
muscle, the subcutaneous and submucosal con-
nective tissues, the oral and nasal epithelia lining
the spaces, the vessels, and the nerves all com-
bine to move the facial bones passively along
with them as they grow. This continuously places
each bone and all of its parts in correct anatomic
positions to carry out its functions. Indeed, the
functional factors are the very agents that cause
the bone to develop into its de fi nite shape and
size and to occupy the location it does.
Growth control is determined by genetic
in fl uences and biomechanical forces, but the
nature of the balance between them is still, at
best, uncertain. No single agent is directly respon-
sible for the master control of growth; the control
process encompasses many factors. It involves a
chain of regulatory links. Moreover, not all of the
individual links are involved in all types of growth
changes.
Enlow ( 1975 ) identi fi es the maxillary tuberos-
ity as being a major site of maxillary growth. It
does not, however, provide for the growth of the
whole maxilla, but rather is responsible for the
lengthening of the maxillary arches. The whole
Fig. 3.2 Similarly, the whole mandible is displaced “away”
from its articulation in each glenoid fossa by the growth
enlargement of the composite of soft tissues in the growing
face. As this occurs, the condyle and ramus grow upward and
backward into the “space” created by the displacement pro-
cess. Note that the ramus “remodels” as it relocates posteri-
orly. It also becomes longer and wider to accommodate
(1) the increasing mass of masticatory muscles inserted onto
it, (2) the enlarged breadth of the pharyngeal space, and (3) the
vertical lengthening of the nasomaxillary part of the growing
face (Reprinted with permission from Enlow ( 1975 ) )

48
S. Berkowitz
maxilla is displaced in an anterior direction as it
grows and lengthens posteriorly. However, the
nature of the force that produces this forward
movement is a subject of great controversy. The
idea that additions of new bone on the posterior
surface of the elongating maxillary tuberosity
“push” the maxilla against the adjacent pterygoid
plates has been abandoned.
Bones do not by themselves have the physio-
logical capacity to push away bones. Another
theory held that bone growth at the various max-
illary sutures produces a pushing apart of the
bones, with a resulting thrust of the whole max-
illa downward and forward. This theory has also
been rejected because bone tissue is not capable
of growth in a fi eld that requires the amount of
compression needed to produce a pushing type of
displacement. The sutural connective tissue is not
adapted to a pressure-related growth process. It is
believed that the stimulus for sutural bone growth
is the tension produced by the displacement of
the bone. Thus, the deposition of new bone is a
response to displacement rather than the force
that causes it. Although the “sutural push theory”
is not tenable, Enlow reports that some students
of the facial growth control processes are looking
anew at growth mechanizing sutures, but not in
the old conceptual way.
3.1.4 Cartilage-Directed Growth:
Nasal Septum Theory
(Scott 1953, 1954, 1955, 1956a, b,
1957, 1958a, b, 1959 )
Cartilages are the leading factor. Synchondrosis,
nasal septum, and mandibular condyles are actual
growth centers. Sutural growth is compensatory.
This theory developed from criticisms of the
“sutural theory.” Scott ( 1953, 1954 ) believes that
cartilage is speci fi cally adapted to certain pres-
sure-related growth sites because it is a special
tissue uniquely structured to provide the capacity
for growth as a result of compression. The basis
for this theory is that the pressure-accommodat-
ing expansion of the cartilage in the nasal septum
is the source of the physical force that displaces
the maxilla anteriorly and inferiorly. This, accord-
ing to Scott’s hypothesis, sets up fi elds of tension
in all the maxillary sutures. The bones then, while
they enlarge at their sutures in response to the
tension created by the displacement process,
move in relation to each other.
The nasal septum hypothesis was soon adopted
by many investigators in cleft palate centers
around the world and became more or less the
standard explanation, replacing the “sutural the-
ory.” Clinicians involved in cleft palate treatment,
such as McNeil ( 1950, 1954, 1964 ) and Burston
( 1960 ) and their followers (Crikelair et al. 1962 ;
Cronin and Penoff 1971 ; Derichsweiler 1958 ;
Dreyer 1962 ; Georgiade 1970 ; Georgiade and
Latham 1975a, b , Graf-Pinthus and Bettex 1974 ;
Hellquist 1971 ; Huddart 1979 ; Kernahan and
Rosenstein 1990 ; Krischer et al. 1975 ; Latham
1968 ; Robertson 1971 ; Monroe and Rosenstein
1971 ) , accepted Scott’s thesis that cartilage and
periosteum carry an intrinsic genetic message
that guides their growth. They believed that the
cartilaginous centers, such as the chondrocra-
nium, the associated synchondroses, and the
nasal septum, should be viewed as the true cen-
ters of skull and facial growth. Scott ( 1953, 1954 )
further suggests that the nasal septum plays more
than a secondary role in the downward and for-
ward vector of facial growth.
McNeil ( 1950, 1954 ) , following Scott’s thesis,
describing the embryopathogenesis of complete
clefts of the lip and palate and their treatment at
the neonatal period, wrote that the palatal pro-
cesses, being detached from the growing nasal
septum, do not receive their growth impetus and,
therefore, are not only retruded within the cra-
nium but are also de fi cient in osteogenic tissue.
He goes still further and believes that the de fi cient
palatal processes can be stimulated to increased
size through the use of functional orthopedics.
3.1.4.1 Stimulation of Bone Growth:
Is It Possible?
As McNeil saw it, pressure forces created by
“functional” orthopedic appliances, which are
within the limits of tolerance, will act to stimu-
late bone growth in an anterior direction. This
force needs to be applied to particular regions
and in particular directions so that it can intensify

49
3 Facial and Palatal Growth
normal forces. The resulting narrowing of the
cleft is due to growth of the underlying bone
brought on by such stimulating appliances.
Additional growth leads to a reduction in the soft
palate cleft as well, thereby increasing the chance
of having a long, fl exible, well-functioning soft
palate after surgical closure.
McNeil ( 1954 ) goes on to suggest that an
obturator alone is unsatisfactory because it will
reduce “valuable” tongue space and lead to harm-
ful speech habits. McNeil was correct in stressing
that surgery should be reduced to a minimum
compatible with sound clinical reasoning and
accepted surgical principles.
Whereas McNeil states that his procedure stim-
ulates palatal growth, thereby narrowing the cleft
space, Berkowitz’s ( 1989 ) 3D palatal growth stud-
ies – using a sample of cases that have not had neo-
natal maxillary orthopedic treatment and a control
sample of noncleft cases – show that growth occurs
spontaneously. This is an expression of the palate’s
inherent growth potential, which can vary among
patients. Berkowitz concluded that “catch-up
growth” can occur after palatal surgery (with mini-
mum scarring) is performed.
3.1.4.2 The Need to Prevent Collapse
McNeil ( 1950, 1954, 1964 ) further believes that
the palatal segments should be manipulated to an
ideal relationship prior to lip surgery to prevent
them from moving too far medially and becom-
ing collapsed with the buccal segments in cross-
bite. This, he suspects, will lead to abnormal
movements of the tongue and give rise to faulty
respiratory, sucking, and swallowing patterns,
also causing abnormal growth and development
of the palatal structures.
Mestre et al. ( 1960 ) , studying palatal size in a
cleft population that had not been operated on,
report that the development of the maxilla appears
to be normal in unoperated cases. They do con-
clude that it is the type, quality, and extent of the
surgery that determine the effect on maxillary
growth and that osteogenic de fi ciency does exist
to varying degrees. Our research on serial palatal
growth changes supports this conclusion that pal-
ates with clefts are highly variable in size, shape,
and osteogenic de fi ciency.
Unfortunately, McNeil’s interpretation of the
effects of clefting on the various vegetative func-
tions, and in reducing palatal growth, has not
been supported by controlled objective research.
The inability of the manipulated arch to remain
intact after lip surgery, and not move medially
into a collapsed relationship, has led many clini-
cians to question the accuracy of McNeil’s other
stated bene fi ts such as reduction of middle ear
infections.
McNeil ( 1950, 1954, 1964 ) made other faulty
observations. Among them:
1. He mistakenly believed that the orthopedic
appliance will stimulate the underdeveloped
cleft segment in unilateral clefts of the lip and
palate (UCLP) to move forward, to make con-
tact with the premaxillary portion of the
greater segment and both palatal segments in
bilateral clefts of the lip and palate (BCLP),
after the lip is united. Even as early as the
1960s, many orthodontists found the opposite
to be true. In UCLP, the premaxillary portion
of the larger segment moves medially and
backward to make contact with the lesser seg-
ment due to the action of compressive lip mus-
cle forces. If McNeil had had the bene fi t of
serial casts, his interpretation of clinical events
would, I am con fi dent, have been totally
different.
2. McNeil’s claim that the lesser segments in
UCLP, and both segments in BCLP, can be
stimulated to grow forward is totally errone-
ous. His conclusions were based on conjec-
ture, not on objective data. The results of
Berkowitz’s 3D palatal growth studies (Wolfe
and Berkowitz 1983 ) show marked accelera-
tion in palatal growth during the fi rst 2 years
without orthopedic treatment, with most of
the growth changes occurring at the area of
the maxillary tuberosity and not at the ante-
rior portion of the palate except for alveolar
growth associated with canine development
(Fig. 3.2 ). Movement of the cleft palatal seg-
ment anteriorly is only possible as a result of
reactive mechanical forces being applied
through the use of pinned maxillary orthope-
dic appliances or from a protraction facial
mask.

50
S. Berkowitz
One last but signi fi cant characterization of a
newborn cleft of the lip and palate needs to be
refuted. McNeil states that “in BCLP lateral seg-
ments are collapsed toward the midline before
birth.” However, he does not explain the dynamics
that can make this possible. How can segments be
collapsed if there are no inwardly directed forces
from the cleft lip–cheek muscle complex, espe-
cially when the tongue fi ts within the cleft space
and acts to move the palatal segments apart?
Enlow’s ( 1975 ) report on current thinking on
palatal growth processes delivers McNeil’s thesis
a mortal blow. Enlow ( 1975 ) writes that recent
research has shown that pressure is detrimental to
bone growth.
Bone is necessarily both a traction and pres-
sure-adapted kind of tissue. The periosteal mem-
branes are constructed to function in a fi eld of
tension (as by the pull of a muscle). Covering
membranes are quite sensitive to direct compres-
sion because any undue amount causes vascular
occlusion and interference with osteoblastic for-
mation of new bone. Osteoclasts, conversely,
function to “relieve” the degree of pressure by
removing bone. Bone is pressure sensitive, and
high-level pressure induces resorption.
Moss et al. ( 1968 ) , responding to the role of
nasal septal cartilage in midfacial growth as put
forth by Scott ( 1953, 1959 ) , states that Scott’s
hypothesis is based on the following assump-
tions: (1) that in the fetal skull, the original nasal
capsule and its derivatives are cartilaginous; (2)
that all cranial cartilaginous tissues (septal, con-
dylar, or in synchondroses) are primary growth
centers, by virtue of the undoubted ability of all
cartilaginous tissues to undergo interstitial expan-
sive growth; and (3) that following the prenatal
appearance of the intramembranous vomer (and
of the several endochondral ossi fi cation centers
of the ethmoid sinuses and the turbinates), the
remaining unossi fi ed portions of the cartilagi-
nous nasal capsule continue to be capable of such
interstitial expansion. Moss further suggests that
the nasal septal cartilage grows as a secondary,
compensatory response to the primary growth of
related orofacial matrices and that midfacial
skeletal growth is not dependent on any prior, or
primary, growth “impetus” of the nasal septal
cartilages.
In Scott’s hypothesis, it is assumed that carti-
laginous interstitial growth is the major source of
the expansive force that “pushes” on the subja-
cent midfacial skeletal structures, causing both
vertical and anteroposterior growth. Moss
believes that it has been demonstrated repeatedly
that growth in size and shape, as well as the
changes in spatial position, of all skeletal units is
always secondary to primary changes in their
functional matrices. This secondary skeletal unit
growth comes about in the following manner. All
cranial bones and cartilages originate and grow
within soft tissue capsules. The splanchnocranial
skeleton exists within an orofacial capsule. The
primary growth of the enclosed orofacial matri-
ces causes the orofacial capsule to expand respon-
sively. Because the splanchnocranial bones are
within this capsule, they are passively translated
in space within their expanding capsule. As a
result of such spatial displacement, the individual
bones will be distracted (or separated) passively
from one another.
The increments of growth observed at the
sutural edges of these bones, and at the mandibu-
lar condylar cartilages, are secondary, compensa-
tory, and mechanically obligatory responses of
the skeletal units to such separative movements
(i.e., the alterations of size and shape in bones
and cartilages are responses to matrix growth, not
the cause of it).
The nasal skeleton is characterized by a rela-
tively great normal variation in form. The nasal
capsule (and septum), from its inception, serves
to protect and support the functional spaces for
respiration and olfaction. In human, the olfactory
spaces are fully formed at birth. Postnatal cavity
growth exclusively increases the respiratory func-
tioning space.
The growth of the upper face is, in part, a
response to the functional demands for increased
respiratory volume. The nasal cavity is not a
space haphazardly left over after the upper facial
structures complete their growth. On the contrary,

51
3 Facial and Palatal Growth
the expansion of the nasal cavity is the primary
morphogenetic event, and nasal capsular growth,
both osseous and cartilaginous, is secondary.
The application of the theory of functional cra-
nial analysis to nasal and midfacial skeletal
growth demonstrates that the growth of each of
these two areas is independent of the other and
that the nasal septal cartilage plays a secondary
compensatory role, rather than a primary mor-
phogenetic one.
At present, the nasal septum theory is some-
what accepted as a reasonable explanation by a
number of clinicians who favor presurgical ortho-
pedic treatment, although it is universally real-
ized that much more needs to be understood
about facial growth processes (Moss 1968 ) . (The
use of presurgical orthopedic treatment is cov-
ered in greater detail in Chaps. 10 and 11 .)
Clinically, there seems to be more support for
the functional matrix theory than the nasal sep-
tum theory. Unfortunately, McNeil, in espousing
Scott’s theory to explain the “retropositioned
maxillary complex relative to the mandible and
osteogenically de fi cient palatal processes” in
complete clefts of the lip and palate, did not have
access to serial palatal and facial growth records
to support such a view. However, Berkowitz’s
( 1985 ) serial casts study of CUCLP and CBCLP
cases using the Angle’s occlusal classi fi cation
system, which is the most reliable means of judg-
ing the geometric relationship of the maxillary to
the mandibular arches within the face, showed
that at 3–6 years of age, the teeth in the lateral
palatal segments were in either a class I or class
II relationship but were never in a class III
relationship.
On this basis, one can conclude that it is not
the lack of a growth impetus from the nasal sep-
tum that explains the presence of a small cleft
palatal segment at birth. If palatal osteogenic
de fi ciency does exist, it can more accurately be
explained in relationship to the embryopathogen-
esis of facial development: the failure of migrat-
ing undifferentiated mesenchymal cells from the
neural crest to reach the facial processes (Millard
1980 ; Ross and Johnston 1972 ) .
3.1.5 Basion Horizontal Concept:
The Direction of Facial Growth
(Figs. 3.3 , 3.4 , and 3.5 ) (Coben 1986 )
No discussion on craniofacial growth is complete
without including Coben’s basion horizontal con-
cept of the direction of facial growth. Basion
horizontal is a concept based on a plane at the
level of the anterior border of foramen magnum
parallel to Frankfort horizontal where basion is
the point of reference for the analysis of craniofa-
fm
em
Im
Pm
NS
SO
C
ptp
zm
fe
Se
Fig. 3.3 Postnatal craniofacial growth systems to the age
of 7 years ( fi rst decade). Cartilaginous growth: SO spheno-
occipital synchondrosis, C re fl ection of condylar mandib-
ular growth, NS nasal septum. Sphenoethmoidal
circumaxillary suture system: se sphenoethmoidal, ptp
pterygopalatine, pm palatomaxillary, fe frontoethmoidal,
em ethmoidal–maxillary, lm lachrymal–maxillary, fm
frontomaxillary, zm zygomaticomaxillary, zt zygomati-
cotemporal (not shown). Surface apposition-modeling
resorption development (stippled area): minor contribu-
tion (Reprinted from Coben ( 1986 ) )

52
S. Berkowitz
cial growth. Coben states that the growth concept
which basion horizontal represents is that cranio-
facial growth is re fl ected away from the foramen
magnum (basion) and the vertebral column. The
cranio-maxillary complex housing the maxillary
dentition is translated upward and forward from
basion by growth of the cranial base. Growth of
the mandible is re fl ected away from basion, car-
rying the mandibular dentition downward and
forward. The divergence of the two general vec-
tors develops space for vertical facial growth and
the eruption of the dentition.
Normal
maxillomandibular
development
requires synchronization of the amount, timing,
SO
C
Fig. 3.4 Postnatal craniofacial growth systems from
age 7 years (second decade). Cartilaginous growth: SO
spheno-occipital synchondrosis-active through puberty,
C re fl ection of condylar mandibular growth – active
to facial maturity, nasal septum – growth completed.
Sphenoethmoidal circumaxillary suture system: sutural
growth no longer primary system of upper facial devel-
opment. Surface apposition-modeling resorption develop-
ment (stippled area): now major method of upper facial
development and alveolar growth (Coben 1986 )
Fig. 3.5 ( a ) Basion horizontal. General vectors of cran-
iofacial growth. Growth of the cranial base translates the
upper face and the maxillary dentition upward and for-
ward away from the foramen magnum. Growth of the
mandible translates the lower dentition downward and
forward. The two diverging vectors create space for ver-
tical facial development and tooth eruption (Coben
1986 ) ( b ) Basion horizontal. Basion horizontal coordi-
nate computer craniofacial serial schematic line graph
of Fig. 3.5a
a
b

53
3 Facial and Palatal Growth
and direction of growth of the cranio-maxillary
complex and of the mandible. The cranial base
vector represents the upward and forward transla-
tion of the upper face by growth of the spheno-
occipital synchondrosis, while growth of the
sphenoethmoidal/circumaxillary suture system
and the nasal septum increases the depth and
height of the upper face.
The basion–articulare dimension is essentially
stable postnatally, indicating that the mandible
maintains a constant sagittal spatial relation to
the foramen magnum as the re fl ection of man-
dibular growth carries the lower teeth downward
and forward, away from the cranial base.
There are two distinct phases of craniofacial
growth because of a change in the system of upper
facial development after the approximate age of
7 years. Before age 7, growth of the upper face is
dominated by the nasal septum, the eyeballs, and
the sphenoethmoidal/circumaxillary suture sys-
tem (Fig. 3.4 ). At this age, the growth in this
suture system produces space for the eruption of
the maxillary fi rst molars. Longitudinal cephalo-
metric fi ndings of a continuous increase in the
sella–frontale dimension with little increase in the
thickness of the frontal bone before age 7 support
the concept that bone apposition and remodeling
resorption are minor factors in these early years.
At about age 7, the growth system of the upper
face changes with the closure of the sphenoeth-
moidal suture. The sella–frontale dimension stabi-
lizes, and the thickness of the frontal bone begins
to increase by surface apposition and remodeling
until maturity. The interpretation is that after age
7, the initial primary system of sphenoethmoidal/
circumaxillary sutural growth of the upper face
is replaced by surface apposition and remodeling
resorption (Fig. 3.4 ). It is signi fi cant that, before
age 7, space for the erupting upper fi rst molars
results from growth of the sphenoethmoidal/cir-
cumaxillary suture system. After age 7, space for
the upper second and third molars is produced
by maxillary alveolar apposition as the maxil-
lary dentition erupts downward and forward.
This concept was supported by Scott ( 1959 ) ,
who reasoned that the sphenoethmoidal suture
must be viewed as part of the major circumaxil-
lary suture system and that once part of the suture
closes, there is no further growth in that suture
system. Longitudinal cephalometric growth stud-
ies con fi rm this interpretation (Fig. 3.5 ).
3.2
Mandibular Development in
Cleft Palate (Figs. 3.6 and 3.7 )
Recent studies have revealed a series of often sub-
tle differences in the morphology of the mandible
in persons with cleft lip and/or palate. Dahl ( 1970 )
and Chierici and associates (Chierici et al. 1973 )
found that, in persons with clefts of the hard pal-
ate only, the mandibular plane was steeper and the
gonial angle more obtuse than in a normal popula-
tion. Mazaheri and coauthors ( 1971 ) noted that
the length and width of the mandible were
signi fi cantly less in persons with cleft palate only
than in those with cleft lip and palate (CLP) and
normal groups. Aduss ( 1971 ) observed that the
mandibular gonial angle in patients with unilateral
CLP was more obtuse and that the anterior cranial
base appeared to be elevated. Rosenstein ( 1975 )
also found the mandibles to be smaller, with
steeper mandibular plane angles. Bishara ( 1973 )
studied Danish children with repaired cleft palates
only. In that study, and again in a later study of
patients with CUCLP (Bishara et al. 1979 ) , he
noted that the mandible was signi fi cantly more
posterior in relation to the cranial base and that its
mandibular plane was steeper than normal.
Krogman and colleagues ( 1975 ) found no
difference in mandibular dimensions in the
BCLP population, other than a more obtuse
gonial angle. They also found the temporoman-
dibular joint to be positioned farther back so
that its effective length was less than in the nor-
mal population. Robertson and Fish (Robertson
and Fish 1975 ) , comparing mandibular arch
dimensions, found no signi fi cant differences
between normal and cleft children either at birth
or at 3 years of age.

54
S. Berkowitz
Vertical growth
A
B
a
b
1
2
Horizontal growth
Total change
AA
BB
Fig. 3.6 Various growth changes that occur in the condylar head determine the direction and extent of mandibular
growth

55
3 Facial and Palatal Growth
3.3
Patterns of Postnatal Growth
Based on the serial studies, three general patterns
of postnatal growth have been demonstrated. In the
Pierre Robin sequence, and in complete bilateral
clefts of the lip and palate, most cases demonstrate
substantial improvement through “catch-up” in the
growth of the mandible. In the second pattern,
mandibulofacial dysostosis, the pattern of growth
is such that the deformity observed in infancy or
early childhood is maintained throughout the
growth period. The deformity of the mandible nei-
ther improves nor worsens in the course of time.
The third pattern is one in which the growth process
is so deranged that the severity of the deformity
increases with age. This has been observed in some
instances of unilateral agenesis of the mandibular
ramus (e.g., hemifacial microsomia) and in the
growth of the maxilla and neurocranium in some
forms of premature craniofacial synostosis.
Facial growth rotations resulting from differertial vertical growth
FH
a
c
b
Posterior growth rotation
(hyperdivergence)
Anterior growth rotation
(hypodivergence)
A-Hyperdivergent
B-Neutral
C-hypodivergence
Neutral growth pattern
A
B
C
Fig. 3.7 ( a – c ) Facial growth rotations resulting from dif-
ferential vertical growth. ( a ) Hyperdivergent pattern with
posterior growth rotation. ( b ) Neutral growth pattern.
( c ) Hypodivergent growth pattern with anterior growth
rotation. Comment: This series is not a true re fl ection of
the growth of various components of the face. See Coben’s
basion horizontal, coordinate craniofacial analysis system
for this (Fig. 3.5 )

56
S. Berkowitz
3.3.1 Bone Remodeling During
Growth (Fig. 3.8 )
Enlow ( 1975 ) states that remodeling is a basic
part of the growth process. The reason why a bone
must remodel during growth is because its regional
parts become moved; “drift” moves each part
from one location to another as the whole bone
enlarges. This calls for sequential remodeling
changes in the shape and size of each region. The
ramus, for example, moves progressively posteri-
orly by a combination of deposition and resorp-
tion. As it does so, the anterior part of the ramus
becomes remodeled into a new addition for the
mandibular corpus. This produces a growth elon-
gation of the corpus. This progressive, sequential
movement of component parts as a bone enlarges
is termed relocation. Relocation is the basis for
remodeling. The whole ramus is thus relocated
posteriorly, and the posterior part of the lengthen-
ing corpus becomes relocated into the area previ-
ously occupied by the ramus. Structural
remodeling from what used to be part of the ramus
into what then becomes a new part of the corpus
takes place. The corpus grows longer as a result.
3.3.2 Maxillary Growth
The maxilla grows downward and forward from
the cranial base with growth occurring at the
articulations with other bones (i.e., the sutures).
Björk ( 1975 ) stated that during growth the max-
illa is displaced in a rotational manner relative to
the cranial base; however, this rotational aspect is
small, which results in the downward and for-
ward effect. Furthermore, he emphasized that
there is little variation in the upper facial height
between groups. Therefore, because of the small
variation, it is likely that individual difference in
facial form results from growth in other facial
areas where there is more variation.
–11
+6
+9
98
92
91
87
81
81
+9
–6
+2
50%
61%
Fig. 3.8 Variations in facial growth patterns. Courtesy of Ricketts ( 1956 )

57
3 Facial and Palatal Growth
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Berkowitz S (1989) Timing cleft palate closure-age should
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Berkowitz S (1989) Cleft palate. In: Wolfe SA, Berkowitz
S (eds) Plastic surgery of the facial skeleton. Little,
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Bishara SE (1973) Cephalometric evaluation of facial
growth in operated and non-operated individuals
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Bishara SE, Sierk DL, Huang KS (1979) A longitudinal
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Björk A (1975) The use of metallic implants in the study
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Part II
Types of Clefts

61
S. Berkowitz (ed.), Cleft Lip and Palate,
DOI 10.1007/978-3-642-30770-6_4, © Springer-Verlag Berlin Heidelberg 2013
4
4.1
Varieties of Cleft Lip and Cleft
Palate
4.1.1 Action of Intact Facial Muscular
Forces on the Maxillary Arch
In a normal jaw with intact lips and palate, the
muscles of the lip, cheek, and pharynx exert
their normal sphincter-like actions against the
developing maxillary and mandibular arches.
The compressive external muscular forces neu-
tralize the expansion forces of the tongue
(Fig. 4.1 ). The neonatal arch form changes as
these forces change with growth and maturation,
yet the opposing muscles always maintain a pre-
cise and dynamic balance with each other. When
this muscular balance is upset, the arch form and
teeth relationships change.
The Effect of Clefting of the Lip
and Palate and the Palatal Arch Form
Samuel Berkowitz
S. Berkowitz , DDS, M.S., FICD
Adjunct Professor, Department of Orthodontics , College
of Dentistry, University of Illinois , Chicago , IL , USA
Clinical Professor of Surgery and Pediatrics (Ret),
Director of Research (Ret), South Florida Cleft Palate
Clinic, University of Miami School of Medicine ,
Miami , FL , USA
Orbicularis oris
a
b
Baccinator
muscle
Pterygo-mandibular
raphe
Pharyngeal tubercle
Superior constrictor
muscle
Lip
force
Tongue
force
Fig. 4.1 The balance between facial and tongue muscle
forces. ( a ) The outer muscles, the orbicularis oris, bucci-
nator, and superior constrictor muscles form a ring which
acts to compress the palatal and mandibular arches with
the teeth. ( b ) The tongue force acts to expand the dental
arches and teeth. Whether the teeth and arches align is
determined by the resultant of these forces
Consultant (Ret), Craniofacial Anomalies Program ,
Miami Children’s Hospital , Miami , FL , USA
e-mail: sberk3140@aol.com

62
S. Berkowitz
4.2
Aberrant Muscle Forces in
Clefts of the Lip and Palate
A cleft of the lip and palate is the result of the
failure of lip elements, and right and left palatal
segments, to come together within the fi rst 9 weeks
of fetal life. The loss of muscular continuity of the
orbicularis oris-buccinator-superior constrictor
ring in complete unilateral and bilateral clefts
changes the normal muscular force diagram. The
aberrant muscular forces act to displace tissue
masses. In complete clefts of the lip and palate, if
the lateral palatal cleft segments are detached from
the vomer, they will be pulled laterally by the
external aberrant lip-cheek muscular forces, as
well as spread apart by the tongue pushing into the
cleft space (Fig. 4.2 ). Because clefts differ in their
location and extent, lip and palate clefts can vary
in the degree of geometric distortion, as well as in
the size and shape of the cleft palatal segments.
The muscular forces that act on the bony scaf-
folding of the palate and pharynx begin very early
in intrauterine life; therefore, the palatal and
facial con fi guration at birth has been formed over
the major portion of the infant’s existence prior to
birth.
In complete unilateral clefts of the lip and pal-
ate (CUCLP), the premaxillary portion of the
noncleft segment is pulled anterolaterally. In
addition to the lateral displacement of the lateral
palatal segments, the premaxilla in the larger seg-
ment is carried forward in the facial skeleton. In
complete bilateral cleft lip and palate (CBCLP),
excessive growth in the premaxillary-vomerine
suture is caused by increased tension at this site,
precipitated by mechanical force stresses during
periods of rapid growth (Berkowitz 1959 ;
Pruzansky 1953, 1971 ; Friede 1973, 1977 )
(Fig. 4.3 ). This growth is continuous during early
postnatal years and provides a fourth dimension
a
d
b
c
Fig. 4.2 ( a – d ) Effects of complete clefts of the lip and
palate at birth. In complete cleft lip and palate, with a sepa-
ration in the orbicularis oris ( a ) buccinator ( b ) superior
constrictor ( c ) muscle ring, the aberrant muscle forces plus
the plunger action of the tongue causes the palatal seg-
ments to be pulled and pushed apart. ( d ) premaxillary
vomerine suture. ( a ) In bilateral clefts of the lip and palate,
the premaxilla may be laterally or ventrally fl exed with the
fulcrum at the premaxillary-vomerine suture. ( b ) Complete
unilateral clefts of the lip and palate at birth. The cleft’s
lesser segment and the premaxillary portion of the larger
segment ( d ) are pulled outward. ( c ) Cleft of the lip and
alveolus. The bony distortion is determined by the extent
of alveolar involvement (Courtesy of J. D. Subtelny)

63
4 The Effect of Clefting of the Lip and Palate and the Palatal Arch Form
Fig. 4.3 ( a – c ) Skull with a bilateral cleft and palate. ( a )
The palatal segments have been overexpanded and the
premaxilla protruded by the resultant aberrant muscle
forces. The premaxillary-vomerine suture separates the
premaxilla and the vomer and is a growth site. ( b ) Lateral
cephalometric tracing at birth. Lines connecting various
landmarks create a polygon depicting their geometric
relationships. This tracing of a CBCLP at birth shows the
degree of premaxillary protrusion. S Sella turcica, N
Nasion, a Alpha (the anterior extent of the premaxilla), Po
Pogonion, Gn Gnathion, Go Gonion, PVS Premaxillary-
vomerine suture. ( c ) Occlusal radiograph of the premax-
illa and vomer showing the premaxillary-vomerine suture
( arrow )

64
S. Berkowitz
to the deformity, which can alter the cleft palatal
segments and their associated parts and either
simplify or complicate treatment.
If a soft tissue (mucous membrane, skin, and
fi brous connective tissue), which collectively
forms Simonart’s band, bridges the alveolar cleft,
the attached palatal segments are limited in their
degree of geometric displacement.
4.3
Categories of Clefts
Depending on the elemental characteristics of the
embryology, anatomy, and physiology of the cleft
defect, the varieties of clefts of the lip and palate
may be tabulated into four general categories: (1)
those involving the lip and alveolus, (2) those
involving the lip and palate, (3) those in which
the palate alone is affected, and (4) congenital
insuf fi ciency of the palate. The term “palate” will
include both the hard palate and the velum, or
soft palate (Fig. 4.4 ).
4.3.1 Clefts of the Lip (Figs. 4.5 and 4.6 )
A cleft of the lip may be complete, extending
from the vermilion border to the fl oor of the nose,
or it may be incomplete. There are various degrees
of incomplete lip clefts. Minimal defects involv-
ing only the vermilion border are observed. In
others, the defect may extend to the nose as a
submucous cleft in the muscle band, bridged only
by mucous membrane, skin, and fi brous connec-
tive tissue. The nasal alar cartilage on the side of
the cleft is displaced and fl attened to a greater or
lesser degree, depending on the extent and width
of the cleft. The tip of the nose is deviated toward
the noncleft side.
The cleft in the lip may be unilateral or bilateral,
occurring on one or both sides, respectively. If
bilateral, it may be symmetrical or asymmetrical,
that is, it may or may not involve the lip equally on
both sides (Fig. 4.5b ). It should be noted that, in
bilateral clefts, a median portion of the lip is iso-
lated in the midline and remains attached to the
a
b
c
d
e
f
g
h
Fig. 4.4 ( a – h ) The anatomic classi fi cation system is
based on the location, completeness, and extent of the
cleft deformity. Because the lip, alveolus, and hard palate
develop from different embryonic sources, any combina-
tion of clefting can exist. ( a ) Cleft of the lip and alveolus.
Normal palate. ( b ) Isolated cleft of the hard and soft pal-
ate. Normal lip and alveolus. ( c ) Cleft of the soft palate
and uvulae. ( d ) Cleft of the uvulae. ( e ) Complete unilat-
eral cleft lip and palate. ( f ) Complete bilateral cleft of the
lip and palate. ( g ) Incomplete bilateral cleft of the lip and
palate. ( h ) Complete bilateral cleft of the lip and alveolus
(Courtesy of Wolfe and Berkowitz ( 1989 ) )

65
4 The Effect of Clefting of the Lip and Palate and the Palatal Arch Form
a
b
Fig. 4.5 ( a ) Complete unilateral cleft lip and palate. The
distorted nostril is caused by the aberrant lip muscle
forces. ( b ) Complete bilateral cleft lip and palate with a
widely separated lateral palatal segment. The protruding
premaxilla extends forward of the lateral palatal segments
and is attached to the vomer. The prolabium (central por-
tion of the lip) overlies the premaxilla
a
b
Fig. 4.6 ( a , b ) Incomplete clefts of the lip. ( a ) Unilateral and ( b ) bilateral

66
S. Berkowitz
premaxilla and to the columella. This portion of the
lip contains the philtrum. In complete bilateral
clefts of the lip, the premaxilla protrudes consider-
ably forward of the facial pro fi le (Fig. 4.5b ). It is
attached to a stalklike vomer and to the nasal sep-
tum. The columella appears to be de fi cient, and the
alar cartilages are fl attened on both sides. The effect
on the facial pro fi le is to accentuate further the pro-
trusiveness of the premaxilla and the portion of the
lip which is attached to the facial surface.
The more complete the defect in the lip, the
greater the in fl uence of the cleft on the alveolar pro-
cess. Because of this constant relationship between
the lip and alveolar process, it is not necessary to
include the alveolar process as a separate entity in
this description and classi fi cation. The maxillary
alveolar processes arise from the mesoderm in the
depths of a sulcus separating the lip and palate,
while the tegmen oris gives rise only to the soft pal-
ate and the central part of the hard palate.
The relationship between the degree of the cleft’s
effect on the alveolar process and defects in the
deciduous and permanent dentition is interesting.
The dental defect may be assessed in terms of the
number of teeth, their shape, and structure as well as
the position of the teeth in the dental arch.
Irregularities in the alveolar process range from
small dimples in association with minor clefts in the
lip to actual grooves in the alveolar process to, in
extreme cases of total clefts in the alveolar ridge, dis-
placement of the premaxillary segment toward the
noncleft side. Small dimples or grooves in the alveo-
lar ridge tend to fi ll in as the jaw grows. However, the
deciduous lateral incisor that erupts in this area may
be T-shaped, or otherwise misshapen, and malposi-
tioned in the line of occlusion. Further documenta-
tion and analysis of serial records should provide
detailed information concerning the eruption of teeth
adjacent to the cleft in the alveolar process.
4.3.2 Cleft Lip and Cleft Palate (Fig. 4.7 )
Clefts of both the lip and palate may be unilateral
or bilateral. They may be complete or incom-
plete. In a complete unilateral cleft of the lip and
palate, a direct communication exists between
the oral and nasal cavities on the side of the pal-
ate where the cleft is situated. The nasal septum
is attached to the palatal process on the opposite
side, thus separating the nasal chamber from the
oral cavity.
A remarkable range of variation exists in
each category. Indeed, various degrees of incom-
pleteness of the cleft in the lip and palate may
exist in combinations too numerous to describe
conveniently. Moreover, some unilateral clefts
of lip and palate exhibit wide separation of the
palatal shelves. Others exhibit less separation,
and in some cases, the segments actually over-
lap (Fig. 4.8 ). The palatal segment on the side of
the cleft is often tilted medially and upward.
The vomer is deviated from the midline at the
line of attachment to the palatal process on the
noncleft side. This deviation may be so extreme
that the vomer assumes a nearly horizontal posi-
tion at its inferior margin.
The bilateral cleft lip and palate also may be
complete or incomplete (Fig. 4.9 ). If incomplete,
it may be symmetrical or asymmetrical, depend-
ing on the equality of involvement on both sides.
In the complete bilateral cleft lip and palate, both
nasal chambers are in direct communication with
the oral cavity. The palatal processes are divided
into two equal parts, and the turbinates are clearly
visible within both nasal cavities. The nasal sep-
tum forms a midline structure that is fi rmly
attached to the base of the skull but is fairly mobile
in front where it supports the premaxilla and the
columella. Cephalometric roentgenograms reveal

67
4 The Effect of Clefting of the Lip and Palate and the Palatal Arch Form
Primary palatal clefts
a
b
c
d
e
Secondary palatal clefts
Combined palatal clefts
Unilateral
Bilateral
Fig. 4.7 ( a – e ) Variations in the form, size, and extent of
clefting in primary, secondary, and combined palatal
clefts. Primary palatal clefts (with normal hard palate).
Top row : ( a ) Normal lip. ( b – g ) The clefts may involve the
lip only or may include the alveolus (tooth-bearing area)
as well. The cleft can extend toward the nostril on one or
both sides. Middle row : The cleft of the alveolus can
extend to the incisal papilla on one or both sides to any
degree. Bilateral alveolar clefts: ( c ) incomplete on both
sides, ( d ) incomplete on one side and complete on the
opposite side, and ( e ) complete on both sides. Secondary
palatal clefts: ( a ) normal palate, ( b ) bi fi d uvula, ( c ) cleft of
soft palate, ( d ) isolated cleft palate (moderate), and ( e )
isolated cleft palate (extensive). Combined palatal clefts.
Unilateral : ( a ) Isolated CP with cleft lip and alveolus; ( b )
incomplete unilateral cleft lip and palate ( IUCLP ), cleft
lip and alveolus are incomplete; ( c ) complete unilateral
cleft lip and palate ( CUCLP ); and ( d ) incomplete unilat-
eral cleft lip and palate ( IUCLP ). Bilateral : ( a ) Complete
bilateral cleft of lip and alveolus; ( b ) bilateral-complete on
one side, incomplete on the opposite with complete hard
palate cleft; ( c ) complete bilateral cleft of the lip and
palate; ( d ) bilateral incomplete alveolar cleft on one side,
complete alveolar cleft on opposite side; and ( e ) complete
bilateral alveolar clefts with both palatal segments attached
to the vomer

68
S. Berkowitz
the existence of a suture line, the premaxillary-
vomerine suture, between the vomer and the pre-
maxilla. This suture plays an important role in
facial growth and is also a point of fl exion for the
premaxilla upon the vomer (Fig. 4.3b , c ).
The premaxilla may be small or large, sym-
metrical or asymmetrical. The number of incisor
teeth contained in this segment is directly related
to its size and shape. Permanent teeth may be
missing, and it may contain only one or more
deciduous teeth when the cleft of the lip is com-
plete on both sides, and the premaxilla projects
considerably forward from the facial aspect of
the maxillae. This anterior protrusion is less evi-
dent if the lip is incompletely cleft on one or both
sides.
a
b
c
d
e
f
Fig. 4.8 ( a – f ) Variations in unilateral clefts of the lip and
palate at birth. The palatal segments may be complete ( a ,
c , e , f ) or incomplete ( b, d ); the cleft segment may be
almost of the same length or shorter. The cleft space may
be relatively narrow ( b , d ) or wide ( a , c , e , f )

69
4 The Effect of Clefting of the Lip and Palate and the Palatal Arch Form
a
b
c
d
e
f
g
h
i
Fig. 4.9 ( a – i ) Variations in bilateral cleft lip and palate.
The size of the premaxilla varies with the number of teeth
it contains. Classi fi cation is dependent on the complete-
ness of clefting of the lip and alveolus and whether there
is a cleft of the hard and soft palate. Yet one or both sides
of the hard palate may or may not be attached to the
vomer. If it is attached to the vomer, it is classi fi ed as
being incomplete. Even in complete clefts of the lip and
alveolus, the extent of premaxillary protrusion will vary.
( a ) Incomplete bilateral cleft lip and palate. Complete
cleft lip and palate – left side . Incomplete cleft lip and pal-
ate – right side . ( b ) Complete bilateral cleft lip and palate.
Complete cleft palate – both sides. ( c ) Incomplete bilat-
eral cleft lip and palate. Incomplete palatal clefts – both
sides. ( d ) Complete bilateral cleft lip and palate.
Incomplete right and complete left palate. ( e ) Incomplete
bilateral cleft lip and palate. Incomplete left palate and
complete right palate. ( f ) Complete bilateral cleft of the
lip and palate. Incomplete right and left palatal segments.
( g ) Complete bilateral cleft of lip and palate. Incomplete
left palate and complete right palatal segment. ( h )
Complete bilateral cleft lip and palate. Incomplete left
palate and complete right palate. ( i ) Incomplete bilateral
cleft lip and alveolus. Normal palate

70
S. Berkowitz
4.3.3 Isolated Cleft Palate
In this defect, neither the lip nor the alveolar pro-
cess is involved (Fig. 4.10 ). The cleft may involve
only the soft palate or both the soft and hard
palates but never the hard palate alone. This
observation is in accordance with the fi nding that
fusion of the hard and soft palates proceeds from
front to back (Fig. 4.11 ).
The cleft may extend forward from the uvula
to varying degrees. In some cases, the cleft is
limited to the uvula or to the uvula and soft
a
b
c
d
e
g
h
f
Fig. 4.10 ( a – h ) Variations in isolated cleft palate. The length and width of the cleft space is highly variable. The cleft
extends anteriorly to various distances but not beyond the incisal canal

71
4 The Effect of Clefting of the Lip and Palate and the Palatal Arch Form
palate. In others, it may extend into the hard pal-
ate. It is recommended that a digital examination
of the posterior edge of the hard palate be per-
formed. A midline notching will reveal the pres-
ence of a submucous cleft. The full extent of
submucous clefts can be mapped by cephalomet-
ric laminagraphy or by transillumination through
the nose.
In the extreme form, the cleft palate may
extend anteriorly as far as the nasopalatine fora-
men, the incisal canal. When the cleft involves a
considerable portion of the hard palate, the nasal
chambers are in direct communication with the
oral cavity. In most instances, the nasal septum is
not attached to either palatal process throughout
the extent of the cleft. However, occasional
asymmetries may be noted in which the septum
is attached to a portion of the palatal process on
one side to a greater extent than to the palatal
process on the opposite side.
In this cleft type (Fig. 4.12 ), neither the lip nor
the alveolar process is involved. The cleft may
extend only through the soft palate or through the
soft and hard palates, but it cannot exist in the
A. 12 mm – 6 weeks
B. 18 – 20 mm – 7 weeks
C. 21 – 24 mm – early 8th weeks
D. 25 – 26 mm – mid 8th weeks
G. 31 – 32 mm – early 9th weeks
H. 33 – 35 mm – mid 9th weeks
I. 38 – 41 mm – 9 weeks
E. 27 – 28 mm – late 8th weeks
F. 29 – 30 mm – 8 weeks
Fig. 4.11 Graphic summary of palatal fusion. The measurements and estimated ages given should be regarded as aver-
ages (Redrawn from illustration in Kraus et al. ( 1966 ) )

72
S. Berkowitz
hard palate alone because the fusion of the hard
and soft palates proceeds from front to back
(Figs. 4.13 and 4.14 ).
The cleft may extend anteriorly as far forward
as the nasopalatine foramen. The outline of the
cleft space may be wide or narrow, long or short;
any variation in geometric form can exist
(Figs. 4.15 , 4.16 , and 4.17 ; see Chap. 2 ).
Timing of surgical closure depends on the
width and not the length of the cleft space. Hard
palate clefts are frequently closed simultane-
ously with the soft palate cleft. In some
instances, surgical closure of very wide hard
palate clefts may need to be postponed until
there is additional palatal growth, which may be
as late as 5 or 6 years of age. An obturator with
a pharyngeal extension (speech aid appliance)
can be worn until the palate is closed (Figs. 4.18
and 4.19 ).
The outline of the cleft may be wide or nar-
row, pyriform, or V-shaped. Excessively wide
dental arches often are associated with wide clefts
that extend to a considerable degree into the hard
palate. In such instances, the mandibular dental
arch may be in complete lingual relation to the
maxillary arch so that the cusps of the teeth do
not interdigitate in occlusion.
Lateral cephalometric headplates reveal that
the dorsum of the tongue, at rest, is elevated and
postured within the nasal cavity. During degluti-
tion, the thrusting action of the tongue operates to
separate the palatal processes. These abnormali-
ties in the posture and movements of the tongue
are supported by the observations of speech
pathologists. In this type of cleft, the vomer is
signi fi cantly different in size and form from that
observed in bilateral cleft lip and palate. In both
types, the vomer is seen as a midline structure
extending downward from the base of the skull.
However, in bilateral cleft lip and palate, the infe-
rior border of the vomer is thick and rounded,
whereas in this category – cleft palate only – the
vomer is thin and knife-edged. Serial observations
reveal that the pattern of growth exhibited by the
vomer is different in these two types of clefts.
Several other distinguishing characteristics
apparent in some of the clefts in this category
merit further comment. The high incidence of
mandibular micrognathia found in patients with
cleft palate gives credence to the theory that
during embryonic development the tongue did
not sink below the palatal processes and thereby
prevented their fusion in the midline. This raises
the question of whether more than one causal
mechanism might exist to produce the various
kinds of clefts of the lip and palate.
In an extensive study of the mode of inheri-
tance of cleft lip and cleft palate, Fogh-Andersen
( 1942, 1961 ) concluded that there are two differ-
ent malformations with no genetic connection.
In one group are clefts that involve the lip and
occur most frequently in male patients. The other
group is limited to clefts of the palate, which are
more frequent in female patients. According to
Fogh-Andersen, the manner of inheritance dif-
fers for the two groups.
Obturator
Palatal
surgery
Fig. 4.12 Isolated cleft palate

73
4 The Effect of Clefting of the Lip and Palate and the Palatal Arch Form
Fig. 4.13 Isolated cleft palate. Serial casts demonstrate
that, in some cases, good class I occlusion can occur when
closing the cleft space at 18 months of age, or even later,
using a modi fi ed von Langenbeck surgical procedure.
This occlusal result supports Berkowitz’s contention that
the “critical threshold level” for good palatal growth is
determined by the size of the cleft space relative to the
amount of available mucoperiosteal tissue. This threshold,
which has been determined to be a ratio of cleft size to
palatal size medial to the alveolar ridges of 10 % or less,
is critical to the development of good arch form and occlu-
sion. The threshold ratio, if exceeded by early palatal clo-
sure when the palatal size is relatively small compared to
cleft size, will cause excessive palatal scar tissue resulting
in midfacial growth inhibition