LECTURE 5
Deformation and defects of the upper
and lower jaws: etiology, pathogenesis,
classification, clinic, diagnostics. The
essence of the methods of surgical
treatment and indications for them.
Distraction and compression therapies
defects and deformities of the upper
and lower jaw treatment.
The two jaws are:
upper jaw (maxilla)
lower jaw (mandible)
Macrogenia refers to a chin that grows beyond
normal size, causing the nose and eyes to look
disproportionately small. This may be corrected
surgically by shortening or setting the chin back.
Microgenia refers to a chin that hasn’t developed to
normal/full size, causing the nose and eyes to look
disproportionately large. This may be corrected
surgically by adding more tissue.
Macrognathia refers to an overgrown lower jaw that
juts out beyond the upper jaw. This may be corrected
by surgically reducing excess bone.
Micrognathia refers to a lower jaw that hasn’t grown
enough to be normally-sized. This may be treated with
early orthodontics to align the teeth, followed by
surgical chin advancement.
Malocclusion refers to an excessively long upper jaw,
resulting in a smile that shows most of the gums. This
may be treated surgically by shortening and reshaping
the jaw, followed by orthodontics to align the upper
and lower jaws.
Long Maxilla refers to a chin that grows beyond
normal size, causing the nose and eyes to look
disproportionately small. This may be corrected
surgically by shortening or setting the chin back.
Short Maxilla refers to an upper jaw that is
proportionately too short for the face, which may hide
the teeth and create an abnormal bite. Whether part of
a birth anomaly or a result of an injury, it may be
treated by surgically lengthening the jaw, followed by
orthodontics to align the upper and lower jaws.
Face Defects / Deformities
What are Face Defects / Deformities?
Face Defects / Deformities, also known as Facial Defects /
Deformities are deformities in the growth of the skull and
facial bones. These are congenital deformities (present at
birth) and can be corrected by reconstructive surgery. Face
Defects / Deformities can be Craniofacial Deformities
(affecting the skull), Maxillofacial Deformities (affecting the
upper jaw) and Dentofacial Deformities (affecting the bony
structure and teeth).
What are the different types of Face Defects / Deformities?
•Cleft Lip - Cleft Lip or Hare Lip is a birth defect where the
upper lip is split or separated either in the middle, on one side
or on both the sides.
•Cleft Palate - Cleft Palate is a condition when there is a cleft
or a gap in the palate or the hard part of the roof of your mouth
•Facial Cleft - This is a rare Face Defect / Deformity where a
bone or skin in the middle of the face may be missing.
•Craniosynostosis - This is a congenital Face Defect where the
sutures (fibrous joints) of the skull bones fuse inappropriately
and prematurely.
Plagiocephaly - In this type of Face Defect / Deformity,
the forehead and the brow stop growing. This Face Defect
/ Deformity produces a flattening of the forehead and the
brow on the affected side while the forehead on the
opposite side tends to be excessively prominent.
Brachycephaly - This type of Craniofacial Deformity
refers to a wide and high forehead region to be wide and
high and the eyes may appear wide apart.
Trigonocephaly - In this type of Face Defect / Deformity,
the forehead looks pointed, like a triangle, with closely
placed eyes. This Face Defect occurs due to closure of a
suture that runs from the top of the head down the middle
of the forehead, toward the nose.
Scaphocephaly - This type of Face Defect / Deformity occurs when
the suture that runs front to back, down the middle of the top of the
head fuses prematurely. As a result, the shape of the skull becomes
long and narrow. The skull is long from front to back and narrow
from ear to ear.
•Facial Palsy - This occurs due to paralysis of the facial nerve. In this
kind of Face Defect, there is loss of control over facial expressions.
•Chin Deformity - In this type of Face Defect / Deformity the chin is
unusually small (mirognathia) or may be unusually large (macrognathia)
•Upper Jaw (Maxillary) Deformity - One of the most common type of
Upper Jaw (Maxillary) Deformity is called vertical maxillary excess. In
this Facial Defect, there is excess bone of the upper jaw, the face appears
long, the chin is recessed and the nose large in the profile view.
•Lower Jaw (Mandibular) Deformity - There are two most common
mandibular deformities; mandibular excess (protrusion) and mandibular
deficiency (retrusion).
•Deformational Plagiocephaly - This refers to asymmetrical shape of the
head from repeated pressure to the same area of the head. This kind of
Craniofacial Deformity usually results from keeping the infant's head in
one position for long periods of time or it also be due to torticollis which
is persistent tilt of the head to one side.
•Vascular Malformations - Also known as lymphangioma, anteriovenous
malformations or vascular gigantism. Vascular malformations are present
at birth and increase in size as the child grows.
•Hemangiomas - Also unknown as port wine stain, strawberry
Hemangiomas and salmon patch. These are also called birth marks and
mostly are present at birth (congenital).
•Hemifacial Microsomia - In this Face Defect, the soft tissues and bones
of the ear, mouth and jaw areas on one side of the face are under
developed.
•Microtia - In this Facial Deformity, the ear on one or both sides does not
grow properly and may be accompanied by atresia of the ear canal.
How are Face Defects / Deformities treated?
The optimal time to seek surgical treatment for your child to repair Face
Defects is before one year of age since the bones are still very soft and
easy to work with. Surgical intervention may be necessary at a much
earlier age depending upon the severity of Craniofacial Deformity. In
some cases, surgery may have to be performed in stages to obtain
optimum results. Your child's healthcare team will comprise of several
health professionals (Craniofacial Team) with different expertise to
assess and monitor your child's progress as he/she grows up. The
Craniofacial Team will educate you and your family on how to best care
for your child at home, and will also outline specific problems that
require immediate medical attention. It is important to note that
Craniofacial Deformities do not exist in isolation and may be
accompanied by other congenital abnormalities.
•Cleft Lip - The surgery for Cleft Lip is performed as a single procedure
which also closes the nostril deformity. Bilateral Cleft Lip sometimes
requires two surgeries. Depending on how extensive the birth defect is,
surgery for Cleft Lip can take anywhere from 2 - 3 hours.
•Cleft Palate - This attempt at restoration of normal anatomy of mouth
would hopefully enable your child to eat and speak properly over time.
The operation to repair Cleft Palate may take 2 - 3 hours and your child
will be required to stay in the hospital for 3 - 4 days.
•Craniosynostosis - The goal of surgical treatment to treat this Face
Defect is to reduce the pressure in the head and correct the deformities of
the face and skull bones. Following the operation to correct this Facial
Deformity, it is common for the child to have a turban-like dressing
around his / her head. The head may be reshaped by a non-surgical
method i.e. a cranial molding helmet which allows growth in areas which
appear flattened, and restricts growth in areas which appear prominent.
•Hemengiomas - Hemangiomas can sometimes be
quite disfiguring and may require treatment which
may consist of steroid medications, embolization of
blood vessels or removal by laser or surgical excision.
Following surgical excision, your surgeon may
perform Skin Grafting or use the technique of Skin
Flap Grafting to reconstruct the damaged tissue.
•Vascular Malformations - Facial Defects due to
Vascular Malformations can be treated either by laser
therapy (capillary malformations or port wine stains),
embolization (arterial malformations) or by direct
injection of a sclerosing, (clotting) medicine (venous
malformations).
•Deformational Plagiocephaly - This Craniofacial Deformity can be
treated non-surgically. This can be done by alternating you child's sleep
position (re-positioning) may resolve this problem. If the deformity is
severe and cannot be resolved by re-positioning, then a remodeling band
or helmet may be recommended. the helmet is made of a hard outer shell
and soft inner lining and will help in correcting this deformity by
applying mild pressures to inhibit growth in the prominent areas and
allowing for growth in the flat regions.
•Hemifacial Microsomia - For severely underdeveloped lower jaw,
reconstruction using a bone graft taken from the ribs may be
recommended. The external ear and the soft tissue of the cheeks would
be reconstructed to attain facial symmetry.
•Chin Deformity - This deformity can be treated by osseous genioplasty,
or bony chin advancement, which is a simple procedure that moves a
patient's own chin. Variety of facial implants can also be used to correct
this Facial Deformity. Unusually large chins can be treated by bone
reduction.
What will my child's Craniofacial Team comprise
of?
Craniofacial team will comprise of pediatrician,
pediatric plastic surgeon with expertise in Craniofacial
Deformities, neurosurgeon, pediatric dentist,
orthodontist, speech therapist, E.N.T. specialist, eye
specialist, hearing specialist, psychiatrist, social
worker and genetic counselor. Your child's craniofacial
team will play a very important role in his care,
education and rehabilitation that would be on-going
depending on his or her needs.
What is Distraction Osteogenesis procedure to treat Face Defects /
Deformities?
Distraction Osteogenesis (DO) - Also known as Bone Expansion. The
method of Distraction Osteogenesis stimulates natural growth of new bone by
stretching eventually leading to widening and lengthening of upper and lower
jaw. Distraction Osteogenesis involves making small cuts in your jaw bone and
applying forces by a distraction apparatus (DO device) which is attached to the
teeth. The new bone will be formed (to fill the gaps in between the cuts) in
response to the forces applied by this apparatus. The DO device is adjusted
periodically until the desired lengthening and widening of the jaw bones is
achieved. The device stays in place for about six to eight weeks to ensure that
the gap is filled-in with stable new bone. It is removed in the operating room
under sedation. New bone grows at the rate of one millimeter per day. Bone
distraction requires two surgeries, one to implant the device and another to
remove the device after the desired bone growth is achieved. It takes about six
weeks for the new bone to heal and consolidate, and the device usually leaves
only small scars. Distraction Osteogenesis is performed in 2 stages; first stage is
implantation of the DO device and the second stage is removal of DO device.
What is the outcome of procedure(s) to treat Face
Defects / Deformities?
The procedure(s) to treat Face Defects /
Deformities have a good success rate provided they
are diagnosed and treated in a timely fashion. A
multidisciplinary approach to the treatment of Face
Defects / Deformities has improved the management
strategies and thus the outcomes. The
multidisciplinary team provides care and support for
the medical, physical, and psychosocial needs of the
child and the family.
B . R . A . N . D . of corrective treatments for
Face Defects / Deformities
Benefits of corrective treatments for Face Defects /
Deformities
•With the availability of state-of-art computer imaging system,
you will have a better idea of the results that might be
achieved by surgical intervention. A formal treatment plan will
be put together utilizing the skills and expertise of craniofacial
team. Corrective treatments for Face Defects / Deformities
will most definitely improve the esthetics of your child's face,
it will also improve breathing and feeding problems that are
associated with Face Defects / Deformities.
Risks of corrective treatments for Face Defects / Deformities
Like all other Cosmetic & Plastic Surgery procedures, corrective
treatments for Face Defects / Deformities involves the risk of
complications including:
•Asymmetry of your child's face - This a common problem when one
side of your mouth and nose do not match the other side. In such a case,
a revision surgery is performed to try and match both the sides of the
face as closely as possible.
•Incomplete repair of the Face Defects / Deformities - A second
operation or revision surgery may be required for complete correction.
•Infection of the incision site
•Allergic reaction to anesthesia
•Bleeding, swelling, bruising and delayed healing - It is normal to have
some bruising and oozing of bloody discharge from the face areas which
will soon subside.
Alternatives to corrective treatments for Face Defects
/ Deformities
•The treatment options discussed above are the best
available for children born with Craniofacial
Deformities.
Now or Never
Face Defects / Deformities can range from mild
abnormalities of the teeth to extensive deformities
involving the entire face and skull. Sophisticated
reconstructive surgical techniques yield tremendously
gratifying and outstanding aesthetic and functional
results.
Decision to have corrective treatments for Face
Defects / Deformities
•Each child's and family's needs are unique for
corrective treatments for Face Defects /
Deformities and the treatment plans are
customized to meet all of a child's physical and
emotional needs i.e. from special dietary or
language requirements, to educational or
emotional considerations.
Craniometry and
Functional
Craniology
Lecture outline
1. Introduction: definition, scope, and objectives
2. Kinematics and dynamics
3. Biomechanics: forces, deformation, stresses, strains
4. Form and Function
5. Bone remodeling and growth directions
6. Moss’ Hypothesis: Functional Matrix Hypothesis
7. Clinical applications
Functional Craniology
• Definition: The study of the craniofacial complex in relation to the fields of
functional anatomy, comparative anatomy, embryology, and
growth and development.
• Scope: anatomy, embryology, histology, physiology, growth and development
of the head and neck regions; theories of craniofacial growth;
craniometry and cephalometry; and others
• Objectives: 1) to relate the function to the morphology of the craniofacial
complex.
2) to apply the theories of craniofacial growth and biomechanics
to better understand the morphology, ontogeny and phylogeny
of the craniofacial complex
3) to provide the scientific basis for the clinical applications in
the treatment of craniofacial anomalies.
Kinematics
The measurement and description of the
changes in size, shape, and location of the
craniofacial complex.
Dynamics
The interpretation and description of the
biological processes of the changes in size,
shape, and location of the craniofacial
complex.
Kinematics
The description of measurement.
The description of the changes in size, shape, and location based on
observations and measurements.
The why, who, how, which and where, and what in measurement.
1) The history, scope, definition, and objectives of anthropometry
2) Introduction to craniometry and cephalometry
3) Define anatomical landmarks
4) Define anthropometric, craniometric, cephalometric measurements
5) Measuring devices and technical assessments
6) Data analysis, result descriptions
a) qualitative vs quantitative
b) absolute vs relative
c) statistical analysis
Dynamics
What is the true meaning of a measurement?
How to see beyond the numbers? And what are we looking for?
What makes the changes in size, shape, and location of an organism
or a structure (the transformation)?
What are the modern hypotheses, paradigms, and syntheses in
understanding these kinematic changes?
1) Introduction to functional craniometry
2) Basic principles in growth and development, especially in
osteology and biomechanics.
3) The functional, biological, and mechanical interpretations of the
transformation of an organism or a structure.
4) The evolutionary significance: the adaptation and the selection
5) Clinical applications
Terminology used in Biomechanics
Force: compression, tension, bending, shear, and torsion
Deformation: Change of form due to the loading of forces
Stress: the force per unit area
Strain: the dimensional change expressed as a fraction (ratio)
of the subject’s original size
Force
Compression, Tension, Shear, Bending, Torsion
1) Two basic forces: Compression & Tension
2) A combination of compression and tension: Shear & Bending
3) A combination of the above four forces: Torsion
Compression: compression is the direct expression of the force, which pushes
everything towards the center of an object.
Tension: the opposite of compression; the force which pulls everything away from
the center; where there is a compressive force, there must be a tensile force.
Shear: shear is present, when two forces are thrusting in opposite directions but
offset and slide past each other.
Bending: is found between the pulling of tension and the pushing of compression.
Torsion: a result of all the other four forces. Torsion is twist. Torsion is actually a
specialized bending, a circular bending.
Tension
Original status
Compression
Shear
Original status
Bending
Original status
Torsion
Facial Deformation
Facial Deformation
Skeletal Class III, concave profile
Skeletal Class II, convex profile
Source: Dr. Wisanu Charoenkul
Source: Dr. Sonia Abraham
Cephalic Form, Facial Form,
and Arch Form
Dolichocephalic (long and narrow head)
Leptoprosopic (long and narrow face)
Dolichuranic (V shape, narrow maxillary arch)
Source: Dr. Christel Hummert
FM, female,13y 6m
*
FM
Female
13y 6m
Source: Dr. Christel Hummert
Mouth breather; Enlarged pharyngeal tonsil (adenoid)
Form (Structure) and Function
Form (structure) follows Function.
Function determines form (structure).
Function controls form (structure).
Function regulates form (structure).
Form (structure) is
the realization of information and
the product of the functional attributes.
Cranial Sutures
1. Edge-to-edge suture
 No force loading
2. Beveled suture
 Shear force [Squamosal suture]
3. Serrated suture
 Intermittent tension force
[Sagittal suture]
4. Beveled and serrated suture
 Intermittent tension and shear force
5. Butt-ended sutures
 Intermittent compressive force
“Form Follows Function”
Synovial Joints (I)
1. Plane (gliding) joint
 Sliding motion of all directions
[ Intermetatarsal joint]
2. Hinge joint
 Flexion/extension
[ Humeroulnar joint]
“Form Follows Function”
Illustrations: http://www.science.ubc.ca/~biomania/tutorial/bonejt/intro.htm
Synovial Joints (II)
4. Ellipsoidal (condyloid) joint
 flexion/extension,
adduction/abduction,
circumduction, but no rotation
3. Pivot joint
 Rotation
[Radioulnar joint]
[Temporomandibular joint]
“Form Follows Function”
Illustrations: http://www.science.ubc.ca/~biomania/tutorial/bonejt/intro.htm
Synovial Joints (III)
5. Saddle joint
 Similar to ellipsoidal joint,
but freer
6. Ball and socket joint
 flexion/extension,
adduction/abduction,
circumduction, and rotation
[First carpometacarpal
carpometacarpaljoint]
joint]
[Glenohumeral joint]
“Form Follows Function”
Illustrations: http://www.science.ubc.ca/~biomania/tutorial/bonejt/intro.htm
Functional Structure of Skull
(From a mechanical point of view)
In the force loading areas, pillarlike struts serve as mechanically
efficient reinforcements to resist
and dissipate pressure and traction,
especially to the masticatory force.
6
2, 3
1) Fronto-nasal pillar
2) Zygomatic arch pillar with
vertical branch
3) Zygomatic arch pillar with
horizontal branch
4) Basal arch in upper jaw
5) Basal arch in lower jaw
6) Occipital pillar
7) Pterygoid-palate pillars
1
4
5
Functional Structure of Skull
(From a mechanical point of view)
• In the non- or less force loading
areas, adipose tissue and
pneumatic cavities fill those
mechanically neutral areas.
a
b
c
e
d
1) Paranasal sinuses
a) Frontal sinus
b) Ethmoid sinus
c) Sphenoid sinus
d) Maxillary sinus
2) Accessory tympanic spaces
e) Mastoid air cells
Sagittal crests and temporal muscle orientations
Hominids compared to pongids
Hominid: Australopithecine
Temporal muscle fibers oriented towards the
posterior teeth; emphasis on the posterior
teeth in mastication and dietary adaptation
Pongid: male gorilla
Temporal muscle fibers oriented towards the
anterior teeth; emphasis on the anterior teeth
in mastication and dietary adaptation
Bone remodeling
Deposition: the biological process of laying down the bone
Resorption: the biological process of removing the bone
Remodeling: A basic part of bone growth involves simultaneous deposition and
resorption on all inner and outer surfaces of the entire bone. It
provides regional changes in shape, dimensions, and proportions.
Drift: Growth movement of an enlarging portion of a bone by the remodeling. The
combinations of deposition and resorption result in growth movement
toward the depository surface.
Displacement: The growth movement of a whole bone as a unit. The bone is carried
away from its articulation in relation to other bones.
Direction of growth: 1) the direction of drift
2) the direction of displacement
3) the net direction of drift and displacement.
The Growth of the Coronoid Process
Deposition (+); Resorption (-); Direction of growth (arrow)
The Growth of Mandible
Deposition (blue arrow); resorption (white arrow)
The Remodeling (Growth) Direction:
The “V” Principle
Drift vs Displacement
Drift: the growth movement of an enlarging portion of a bone by the remodeling.
Displacement: The growth movement of a whole bone as a unit.
Direction of growth: the net growth direction of drift plus displacement.
Head (craniofacial complex) is a region, where a series of
functions are carried out.
These functions include vision, hearing, speech, mastication,
swallowing & digestion, respiration, neural integration, and
others.
The successful execution of a function requires
biomechanical protection and support.
Moss’ craniofacial growth theory:
Function of the craniofacial complex region is performed
by the Functional Cranial Components (F.C.C).
Functional Matrix Hypothesis
(Moss’ Hypothesis)
“The functional matrix is primary and the
presence, size, shape, spatial position, and
growth of any skeletal unit is secondary,
compensatory, and mechanically obligated to
changes in the size, shape, spatial position of
its related functional matrix” (Moss, 1968)
Functional Matrix Hypothesis
(Moss’ Hypothesis)
“The origin, development and maintenance of
all skeletal units are secondary, compensatory
and mechanically obligatory responses to
temporally and operationally prior demands of
related functional matrices.”
THE FUNCTIONAL MATRIX HYPOTHESIS
One Function
Functional Cranial Component
Functional Matrix
Skeletal Unit
1. Periosteal Matrix -------------------------------> 1. Microskeletal
2. Capsular Matrix --------------------------------> 2. Macroskeletal
a. Masses
b. Functioning spaces
Types of Functional Matrix
1. Periosteal matrix
(e.g., muscles)
Active growth
Deposition and resorption
Affect size and/or shape
2. Capsular matrix
(e.g., brain, oral cavity)
Passive growth
No deposition
No resorption
Affect location
Growth
Craniofacial Growth
Active growth process
Active growth (Periosteal)
+
Passive growth (Capsular)
=
Total growth
1) Sutural growth
2) Bone remodeling
3) Cephalic cartilage growth
Passive growth process
1) The growth of neural,
orbital, CSF, and other
masses and real substances
2) The expansion of oro-nasopharygeal and other
functioning spaces
Use of the “Functional Matrix” in the therapy of
orthodontics, dentofacial orthopedics, and
orthognathic and craniofacial surgery
1. Orthodontics
Periosteal Matrix
[Teeth]
------------>
Skeletal Unit
[Alveolar Bone]
2. Dentofacial Orthopedics and Orthognathic Surgery
Capsular Matrix
-------------> Multiple Skeletal Units
[Functional Appliances]
[Jaw Bones]
Capsular Matrix
-------------> Multiple Skeletal Units
[Distraction osteogensis: e.g., hemifacial microsomia]
[Jaw Bones]
3. Craniofacial surgery
Capsular Matrix
-------------> Multiple Skeletal Units
[Craniotomy: e.g. Crouzon Syndrome]
[cranial bones]
[Distraction osteogensis: e.g., Treacher Collin Syndrome]
[facial and jaw bones]
Introduction: definition, scope, and objectives
Kinematics and dynamics
Biomechanics: forces, deformation, stresses, strains
Form and Function
Bone remodeling and growth directions
Moss’ Hypothesis: Functional Matrix Hypothesis
Clinical applications
References
Enlow, D.H. (1990). Handbook of Facial Growth (3rd edition). Philadelphia,
Pennsylvania: W.B. Saunders Company.
Moyers, R.E. (1988). Handbook of Orthodontics (4th edition). Chicago, Illinois:
Year Book Medical Publishers, Inc.
Proffit, W.R. (2000). Contemporary Orthodontics (3rd edition). St. Louis,
Missouri: Mosby, Inc.
Ranly, DM (1980). A Synopsis of Craniofacial Growth. Norwalk, CT: AppletonCentury-Croft.
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