1. TEMPOROMANDIBULAR JOINT
Submitted by:
Batallones, Amery Rose
Galeno, Chris Carlo
Saunar, Maurice Cheekz
Talag,Bryan Matthew
Ursal, Alyssa Mae
Villacorta, Aimee Carmina

2. TEMPOROMANDIBULAR JOINT
This is the articulation between the condylar head of mandible and the anterior part of
the glenoid fossa of two temporal bones. The mandibular articulation with the skull on each
side is better termed as Craniomandibular Joint since the articulation is between the movable
mandible and the immovable cranium or skull. The articulation is bilateral because the left and
right sides work as a unit and this is the only visible free moving articulation in the head.
Temporomandibular Joint has distinct features compared to the other joints: The
coordinated movements of the right and left joints are complex and usually are controlled by
reflexes. Both the maxillae and mandible carry teeth whose shape and position greatly affect
the most closed portions of mandibular movements. The articulating surface of the TMJ is not
formed of Hyaline cartilage but of a sturdy avascular fibrous layer. TMJ is the only synovial joint
in the body with articulating disc which is present between the joint surfaces of cranium and
mandible which makes it a double joint.
Classification of Joints
Joints are classified in various ways. Most common and simplistic classifications are
Fibrous joints, Cartilaginous joints, and Synovial Joints.
Fibrous Joints
In a fibrous joint two bones are connected by fibrous tissue and 3 types are described
under this classification of joint, the first type is the suture, it is a joint that permits little or no
movement. Articulation by processes and indentations interlocked together. Its histology
clearly indicates that the function is to permit growth, since the articulating surfaces are
covered by an osteogenic layer which is responsible for new bone formation to maintain the
suture as the skull bones are separated by the expanding brain. The second type of fibrous joint
is gomphosis, articulation formed by the insertion of a conical process into a socket. It is seen in
the articulation of the teeth with the alveoli of the maxillary bones. In gomphosis, the
functional movement is restricted to intrusion and recovery in response to biting forces. The
third type of fibrous joint is syndesmosis, surfaces are united by interosseous ligament that
permits limited movement. Common examples are the joints between tibia and fibula, and
radius and ulna.

3. Cartilaginous Joints
Cartilaginous joints are classified into primary cartilaginous joints or secondary
cartilaginous joints. In a primary cartilaginous joint, bone and cartilage are in direct apposition.
An example is the articulations of the ribs with their cartilages (costo-chondral). In a secondary
cartilaginous joint, the tissues of articulation occur in the sequence bone-cartilage-fibrous
tissue-cartilage-bone. An example is the pubic symphysis. Cartilaginous joints and fibrous joints
permit little if any movement between the bones involved.
Synovial Joints
In synovial joint, which generally permits significant movement, two bones are united
and surrounded by a capsule that creates a joint cavity. This cavity is filled with synovial fluid
formed by the synovial membrane. The cavity may be divided by an articular disk. Various
ligaments are associated with synovial joints to strengthen the articulation and check excess
movement. Synovial joints are further classified by the number of axes in which the bones
involved can move:
 uniaxial- all movements take place around one axis. Ex. Ginglymus and Pivot-joint
 biaxial- movements around two horizontal axes at right angles to each other or at any
intervening axis between the two. Ex. Condyloid and Saddle-joint
 multiaxial/polyaxial- movements around more than two axes.
Ex. Ball-and-socket joint
Synovial joints are also classified by the shapes of the articulating surface:
a. Planar- a synovial joint in which the opposed surfaces are flat or only slightly curved.
b. Ginglymoid- articular surfaces are molded to each other in such a manner as to permit
motion only in one plane, forward and backward.
c. Pivot- movement is limited to rotation; the joint is formed by a pivot-like process turning
within a ring.
d. Condyloid- one in which an ovoid head of one bone moves in an elliptical cavity of
another, permitting flexion, extension, adduction, abduction and circumduction, but not
axial rotation.

4. e. Saddle- one having two saddle-shaped surfaces at right angles to each other. Same
movement with condyloid articulations.
f. Ball-and-socket- form of joint in which the distal bone is capable of motion around an
indefinite number of axes which have a common center.
Movements of a synovial joint are initiated and affected by muscles working together in
a highly coordinated manner. This coordination is achieved through the joint’s sensory
innervation which establishes Hilton’s Law, the principle that the nerve supplying a joint also
supplies both the muscles that move the joint and the skin covering the articular insertion of
those muscles.
Type of joint of Temporomandibular Joint
The Temporomandibular joint articulation is a synovial joint and described as synovial
sliding-ginglymoid joint articulation because its movements are combination of gliding
movements and a loose hinge movement and also the condyle undertakes rotational
movements which is the initial movement of the jaw when the mouth opens and translational
movements which is the secondary gliding motion of jaw as it is opened widely.
Innervation and Vascularization
Sensory innervation of the temporomandibular joint is derived from
the auriculotemporal and masseteric branches of mandibular branch of the trigeminal nerve.
The arterial blood supply is provided by branches of the external carotid artery,
predominately the superficial temporal branch. Other branches of the external carotid artery
such as deep auricular artery, anterior tympanic artery, ascending pharyngeal artery,
and maxillary artery also contribute to the arterial blood supply of the joint.
The specific mechanics of proprioception in the temporomandibular joint involve four
receptors. Ruffini endings function as static mechanoreceptors which position the
mandible. Pacinian corpuscles are dynamic mechanoreceptors which accelerate movement
during reflexes. Golgi tendon organs function as static mechanoreceptors for protection of
ligaments around the temporomandibular joint. Free nerve endings are the pain receptors for
protection of the temporomandibular joint.

5. In order to work properly, there is neither innervation nor vascularization within the
central portion of the articular disc.
ANATOMY AND HISTOLOGY
I. Anatomy (Bony Structures):
The temporomandibular joint (TMJ)
consists of the condylar head of the mandible
articulating with the glenoid or
temporomandibular fossa of the temporal
bone. The articulating surface of the temporal
bone is convex anteriorly at the tubercle and
concave posteriorly at the fossa. The
articulating surface of the condyle and the
opposing surface of the temporomandibular
fossa, including the anterior tubercle, are covered by fibrocartilage. Chondrocytes in the
posterior aspect of the mandibular condyle, a region exposed to greater tensional forces than
compression, express collagen types I and II.
The condyle of the mandible is composed of cancellous bone covered by a thin layer of
compact bone. The trabeculae are grouped in such a way that they radiate from the neck of the
mandible and reach the cortex at right angles, thus giving maximal strength to the condyle. The
large marrow spaces decrease in size with progressing age by a marked thickening of the
trabeculae. The red marrow in the condyle is the myeloid or cellular type. In older individuals it
is sometimes replaced by fatty marrow.
During the period of growth layer of hyaline cartilage lies underneath the fibrous
covering of the condyle. This cartilaginous plate grows by apposition from the deepest covering
connective tissue. At the same time its deep surface is replaced by a bone. Remnants of this
cartilage may persist into old age.

6. The roof of the mandibular fossa consists of a thin compact layer of bone. The articular
tubercle is composed of spongy bone covered with a thin layer of compact bone. In rare cases,
islands of hyaline cartilage are found in the articular tubercle.
Articular fossa is resembles the long axis of that of the condyle. The root of the fossa is
very thin, indicating that the role of this part of the joint is rather passive. The deeper part of
the fossa apparently acts more or less as a bed for the thicker posterior part of the articular disc
when it is resting in its most posterior position. The articular surface proper is the posterior and
inferior part of the articular eminence , which is a roll of bone, more or less steep in its
posterior slope, with an anteroposterior curvature of variable constricture.
It has already been pointed out that the cranial and mandibular surfaces of the joints
are not congruent. They do not touch each other even when the teeth are in intercuspal
contact. The distance from the articular surface of the condyle to the opposing cranial surface is
filled by an articular disc.
II. Histological Part:
Articular Capsule
It is attached to the fossa, to the tubercle of the temporal bone, and to the neck of the
condyle.
It is consist of an outer fibrous layer that is strengthened on the lateral surface to form
the temporomandibular ligament. The inner or synovial layer is a thin layer of connective tissue.
It contains numerous blood vessels that form a capillary network close to its surface. From its
surface, folds or fingerlike processes (synovial folds or villi) protrude into the articular cavity. A
few fibroblast of the synovial membrane reach the surface and, with some histiocytes and
lymphatic wandering cells, form an incomplete lining of the synovial membrane.
A small amount of a clear, straw-colored viscous fluid, synovial fluid, is found in
the articular space. It serves as a:
1. Lubricant: As it the principal role of synovial fluid is to reduce friction between the
articular cartilage of synovial joints during movement.
2. Nutrition: Providres as fluid for the avascular tissues covering the condyle and the
anterior tubercle and for the disc.

7. 3. Regulatory: Separates the articular disk from the articulating surfaces.
This is elaborated by diffusion from the rich capillary network of the synovial
membrane, augmented by mucin possibly by the synovial cells.
Articular Disk
In young individuals, it is composed of dense fibrous tissue. The interlacing fibers are
straight and tightly packed. Elastic fibers are found only in relatively small numbers. The
fibroblast in the disc are elongated and send flat cytoplasmic winglike processes into the
intertices between the adjacent bundles.
With advancing age, some of the fibroblast develop into the chondroid cells, which later
may differentiate into true chondrocytes. Even small islands of hyaline cartilage may be found
in the discs of the older persons. Chondroid cells, true cartilage cells, and hyaline ground
substance develop in situ by differentiatin of the fibroblast. In the disc as well as in the fibrous
tissue covering the articular surfaces this cellular change seems to be dependent upon
mechanical influences. The presence of chondrocytes may increase the resistance and
resilience of the fibrous tissue.
The fibrous tissue covering the articular eminence and mandibular condyle as well as
the large central area of the disc is devoid of blood vessels and nerves and has limited ability.
Articular Surface of the Temporal Bone
The fibrous layer covering the articulating surface of the temporal bone is thin in the
articular fossa and thickens rapidly on the posterior slope of the artcular tubercle. In this region,
the fibrous tissue shows a definite arrangement in two layers, with a small transitional zone
between them.
a. Inner Zone – the fibers are at right angles to the bony surface.
b. Outer Zone – they run parallel to the bony surface.
As in fibrous covering of the mandibular condyle, a variable number of chondrocytes are
found in the tissue on the temporal surface. In adults the deepest layer shows a thin s=zone of
calcification. There is no continuous cellular lining on the free surface of the fibrocartilage. Only
isolated fibrolast are situated on the suface itself. They are characterized by the formation of
long, flat cytoplasmic processes.

8. Mandibular Condyle
It is composed of a fibrous layer of tissue that is of fairly even thickness. Its superficial
layers consist of a network of strong collagenous fibers. Chondrocytes may be present and they
have a tendency to increase in number with age. They can be recognized by their thin capsule,
which stains heavily with basic dyes. The deepest layer of the fibrocartilage is rich in chondroid
cells as long as growing hyaline cartilage is present in the condyle. It contains only a few thin
collagenous fibers. In this zone the appositional growth of the hyaline cartilage of the condyle
takes place during the period of growth.
Unlike the articulating surfaces in most joints of the body, the mandibular condyle is not
covered by naked hyaline cartilage. Instead, its articulating cartilage surface is covered by a thin
layer of poorly vascularized dense connective tissue with few fibroblasts. Collagen type I is the
major constituent found in this outer layer.
However, during its development phase, the growing condyle is covered by a
perichondrium and its bulk is made up of typical hyaline cartilage. A similar fibrous layer covers
the surface of the temporomandibular fossa and articular tubercle. The inner region of this
fibrous layer retains progenitor cells that give rise to prechondrocytes.
Function of Mandibular Condyle:
1. Adapts the shifting vector of force, such as in chewing.
2. Undergo changes, some of which are related to changes in mandibular function and
occlusion, since throughout life, the shape of the condyle undergo changes.
III. Synovial Tissue
A synovial membrane covers the inner surface of the joint capsule. The synovial
membrane does not cover the articulating surfaces and the corresponding parts of the
articulating disk. The synovial membrane is neither an epithelial lining nor an actual
membrane; rather it is composed entirely of connective tissue rich in collagen V. The
synovial membrane is well vascularized with numerous fenestrated capillaries.
Histopathologic studies indicate that there is substantial variation in the morphology of
the synovial lining of the normal TMJ, and that synovial inflammation of the TMJ tends to be
less severe than that arising in other joints.

9. IV. Ligaments
1. Lateral Temporomandibular Ligament
- Strengthens the lateral aspect of the capsule, and its fibers run downward
and backward from the tubercle on the root of the zygoma to the lateral
surface of the neck of the mandible. This ligament limits the movement of
the mandible in a posterior direction and thus protects the external auditory
meatus.
2. Sphenoparietal Ligament
- Lies on the medial side of the joint. It is thin band that is attached above to
the spine of the sphenoid bone and below to the lingual of the mandibular
foramen. It represents the remains of the first pharyngeal arch in this region.
3. Stylomandibular ligament
- Lies behind and medial to the joint and some distance from it. It is merely a
band of thickened deep cervical fascia that extends from the apex of the
styloid process to the angle of the mandible.
DEVELOPMENT OF THE TMJ
The development of the TMJ involves the following structures:
Mandible
Glenoid fossa
Condyle
Articular disc
Upper joint cavity and Lower joint cavity
At 12 weeks of the gestation, the TMJ begins to develop which is marked by the
appearance of two distinct regions of mesenchymal condensation: the temporal/glenoid
blastema and condylar blastema where the glenoid fossa and condyle arise respectively.

10. Mandible
The Meckel’s cartilage is the one responsible for the skeletal support for the
development of the mandible or the lower jaw that begins from 6 th to 7th week. It extends from
the midline that goes laterally and posteriorly.
Formation of the Glenoid Fossa
Between 10th to 11th week, bone formation in the temporal blastema had begun and
continues anteriorly while the condylar blastema remains undifferentiated and in between
them is a gap.
Formation of the Condyle
The condyle, at first is cartilaginous, develops between the 10th and 11th weeks from the
accumulation of mesenchymal cells called condylar blastema that is lateral to Meckel's cartilage.
Enchondral ossification progresses apically, creating a bony fusion with the body of the mandible.
Immediately above the condylar blastema appears a cleft which becomes the lower joint cavity
and then as the condylar blastema differentiates into a cartilage called condylar cartilage. A
second cleft then appears in relation to the ossification of the temporal bone for the glenoid
fossa which becomes the upper joint cavity.
Formation of the Upper and Lower Joint Cavity
The lower joint space appears first at about the 10th week, but later the upper joint
space overtakes it in its development.
The upper joint space appears after about the 12th week and spreads posteriorly and
medially over Meckel's cartilage with its contour corresponding to that of the future fossa. After
13th week the lower joint space is already well formed as the upper joint space continues to
take shape. From its beginning, the upper joint space has fewer individual islands of space and
grows more rapidly than the lower joint space. After 14th week both joint spaces are completely
formed.
Formation of the Articular Disc
With the formation of these two clefts is the formation of the primitive articular disc.
The articular disk can first be identified after 7.5 weeks in utero as a horizontal concentration

11. of mesenchymal cells. Between weeks 19 and 20 its typical fibrocartilaginous structure is already
evident.
MUSCLES OF MASTICATION
The Masseter is a thick, somewhat quadrilateral muscle, consisting of two portions,
superficial and deep. The superficial portion, the larger, arises by a thick, tendinous
aponeurosis from the zygomatic process of the maxilla, and from the anterior two-thirds of the
lower border of the zygomatic arch; its fibers pass downward and backward, to be inserted into
the angle and lower half of the lateral surface of the ramus of the mandible. The deep
portion is much smaller, and more muscular in texture; it arises from the posterior third of the
lower border and from the whole of the medial surface of the zygomatic arch; its fibers pass
downward and forward, to be inserted into the upper half of the ramus and the lateral surface
of the coronoid process of the mandible. The deep portion of the muscle is partly concealed, in
front, by the superficial portion; behind, it is covered by the parotid gland. The fibers of the two
portions are continuous at their insertion.
The Temporalis (Temporal muscle) is a broad, radiating muscle, situated at the side of
the head. It arises from the whole of the temporal fossa (except that portion of it which is
formed by the zygomatic bone) and from the deep surface of the temporal fascia. Its fibers
converge as they descend, and end in a tendon, which passes deep to the zygomatic arch and is
inserted into the medial surface, apex, and anterior border of the coronoid process, and the
anterior border of the ramus of the mandible nearly as far forward as the last molar tooth.
The Pterygoideus externus (External pterygoid muscle/Lateral pterygoid muscle) is a
short, thick muscle, somewhat conical in form, which extends almost horizontally between the
infratemporal fossa and the condyle of the mandible. It arises by two heads; an upper from the
lower part of the lateral surface of the great wing of the sphenoid and from the infratemporal
crest; a lower from the lateral surface of the lateral pterygoid plate. Its fibers pass horizontally
backward and lateralward, to be inserted into a depression in front of the neck of the condyle
of the mandible, and into the front margin of the articular disk of the temporomandibular
articulation.

12. The Pterygoideus internus (Internal pterygoid muscle/Medial pterygoid muscle) is a
thick, quadrilateral muscle. It arises from the medial surface of the lateral pterygoid plate and
the grooved surface of the pyramidal process of the palatine bone; it has a second slip of origin
from the lateral surfaces of the pyramidal process of the palatine and tuberosity of the maxilla.
Its fibers pass downward, lateralward, and backward, and are inserted, by a strong tendinous
lamina, into the lower and back part of the medial surface of the ramus and angle of the
mandible, as high as the mandibular foramen.
Nerves.—The muscles of mastication are supplied by the mandibular nerve.
Actions.—The Temporalis, Masseter, and Pterygoideus internus raise the mandible
against the maxillæ with great force. The Pterygoideus externus assists in opening the mouth,
but its main action is to draw forward the condyle and articular disk so that the mandible is
protruded and the inferior incisors projected in front of the upper; in this action it is assisted by
the Pterygoideus internus. The mandible is retracted by the posterior fibers of the Temporalis.
If the Pterygoidei internus and externus of one side act, the corresponding side of the mandible
is drawn forward while the opposite condyle remains comparatively fixed, and side-to-side
movements. Such as occur during the trituration of food, take place.
Table 1. Muscles of Mastication
Muscle Origin Insertion Nerve Supply Action
Lateral surface Elevates
Masseter Zygomatic arch ramus of mandible to
mandible occlude teeth
Anterior and
superior fibers
Coronoid
Floor of elevate
Temporalis process of
temporal fossa Mandibular mandible:
mandible
division of posterior fibers
trigeminal nerve retract mandible
Greater wing of (V3)
Lateral Neck of Pulls neck of
sphenoid
pterygoid mandible mandible
Lateral
(two heads) Articular disc forward
pterygoid plate
Tuberosity of
Medial Medial surface
maxilla Elevates
pterygoid of angle of
Lateral mandible
(two heads) mandible
pterygoid plate

13. BIOMECHANICS
MANDIBULAR POSITIONS
1. Postural Position of Mandible
 Muscles of mastication are relaxed
 Teeth are not in contact in mastication, swallowing or
speech
 Lips at rest and jaws apart
 Free Way Space or Vertical Dimension of Rest
• Space between mandibular and maxillary teeth
when mandible is in postural position. Average space = .3 – .7 mm
2. Centric Occlusal Relation
 Position of the mandible with maximum intercuspation of teeth.
3. Right Lateral Occlusal Relation
 Points to the right of centric relation.

14. 4. Left Lateral Occlusal Relation
 Points to the left of centric relation.
5. Protrusive Occlusal Relation
 Anterior upper and lower incisors are into an edge-to-edge contact.
MANDIBULAR MOVEMENTS
It is named after the direction of movement of the mandible takes as it moves from the
intercuspal position.
1. Right Lateral Movement
 Jaws move to the right bringing the teeth together in a right lateral occlusal
relation.

15. 2. Left Lateral Movement
 Jaws move to the left bringing the teeth in a left lateral occlusal relation.
3. Protrusive Movement
 Mandible depressed then moves forward bringing a protrussive occlusal relation.
4. Retrusive Movement
 Both condyles are upward and back into the mandible fossa.
 Teeth are in a non-functional occlusal relation.
5. Bennett Movement
 Movement of the mandible to the right or left during mastication.
CLASSIFICATION OF MANDIBULAR MOVEMENTS:
1. Border Movements
 Limits of mandible movement in any direction.
2. Intraborder Movements
 Any mandibular movement within the perimeter of border movements and is
chiefly associated with free movements.
3. Contact Movements
 Movements which the mandibular and maxillary teeth maintain contact.
4. Free Movements
 Movement wherein the reference point failed to reach its border and the teeth
do not come into contact.
ENVELOPE OF MANDIBULAR MOTION (by Posselt)

16. Mandible follows a curved trajectory in opening and closing.
In closing:
 Molars - horizontal path;
 Anterior teeth - vertical movement
Curvature of dental arches enables occlusal balance throughout mandibular movement
range.
CLINICAL CONSIDERATIONS (TMJ)
1. Bruxism
- A condition where in you unconsciously grind, gnash or clench your teeth during day or
night time.
- Over a long period of time, it may tend to causes tooth wear and breakage, disorders
of the jaw (pain and limited movement) and headache.
- This is considered parafunctions of the adults and are thought to result from
physiological stress with or without occlusal interference.
- In children, it has alleged associations with allergies, asthma, digestive upsets,
nervousness. Bruxism In primary dentition is a special problem which might termed a
“functional malocclusion” and not necessarily pathogenic. Genetic factors and
psychosomatic symptoms is correlated with bruxism in children.

17. - This can be artificially induced by sustained tooth clenching like mouth guards/night
guard, Mandibular Advancement Devices.
2. Arthritis
- The synovial fluid is reduced in amount and becomes thicker in viscosity. This result in
pain and swelling in joint capsule. Sometimes very small cyst also appears in condylar heads.
3. Fractures
- The thinness of the bone in the articular fossa is responsible for fractures if the
Mandibular head is driven into the fossa by heavy blow.
- Patients with fractures of the neck of the condyle usually present history of severe
trauma to the symphysis or directly to the joint. Symptoms are swelling, altered
occlusion and pain in the area of the joint.
- when the dentist places a finger in the external auditory meatus while the patient
moves his mandible, no condylar movement is felt.
4. Structural Changes
- The finer structure of the bone and its fibrocartilaginous covering depends upon
mechanical influences. A change in force or direction of stress, occurring especially
after loss of posterior teeth, may cause structural changes. This frequently occurs
after the loss o posterior teeth. The important change is separation between the
collagen bundles (thin, fragile, and separated from each other). This results in the
pain at the TMJ.
5. Disharmony in the relation of teeth and the Temporomandibular joint.
- Clinical symptoms: pain in the region of joint and pain radiating to the temporal,
infraorbital, supraorbital, and postauricular areas, which may be of such severity as
to produce trismus. The joint has palpable irregularities and produces popping and
clicking noises.
6. Myofacial Pain Dysfunction (MPD) Syndrome characterized by
a. pain (dull ache in ear or preauricular area which may radiate to the angle of
mandible

18. b. masticatory muscle tenderness, most frequently, the lateral pterygoid, and then,
the temporalis, medial pterygoid, and masseter.
c. limited opening of mandible (<37mm)
d. joint sounds (clicking or popping noise in the TMJ)
These symptoms are seen more often in females. Hypersensitivity and spasm of the
muscles of mastication account for many of the symptoms. Since the condition may be related
to stress, treatment should be as conservative as possible.
7. Luxation or Dislocation of Temporomandibular Joint
- the Dislocation of Temporomandibular Joint is a forward displacement of the head
of condyle in front of the eminence. (during wide opening of mouth like in yawning)
- *very careful external manipulation of mandible in downward and backward
direction for extrusion of mandible at proper place* happens mostly in aged persons
and mostly in females because of (a) wearing and resorption of articular eminence
(b) reducing muscle tone with the advancing age. Treatment: injection of various
sclerosing solutions are given in TMJ capsular lgaments to tone them up with
variable success rate.
- Treatment of luxation consists of reduction and immobilization for a week, using
interdental arch wires and rubber bands, to permit tissue repair. For acute
dislocation, reduction and immobilization for 2 to 3 weeks to prevent secondary
hemorrhage and to permit tissue repair.
8. Ankylosis
- is immobility and consolidation of joint and its most frequent cause is injury to the
joint or infection in or around the joint. It may occur due to (a) intrauterine fetal
abnormality (b) forcep deliveries (c) malunion of condylar fractures (d) metastatic
malignancies (e) rheumatoid arthritis (f) inflammation of joint from infection in ear like
otitis media
- two types:

19. a. Fibrous ankylosis – also called partial ankylosis, is the result of fibrotic changes in
the joint following hemorrhage caused by external trauma. A slight space can be
seen between the condyle and the fossa in the roentgenogram.
b. Bony ankylosis – is generally the result of infectious or suppurative disease.
Complete bony union between the condyle and the fossa can be seen in the
roentgenogram.
9. Aplasia of condyle
- Failure of development of Mandibular condyle may occur unilaterally or bilaterally. In
unilateral condylar aplasia, there is obvious facial asymmetry toward the affected side.
10. Hypoplasia of Mandibular Condyle
- underdeveloped or defective formation of condyle, which may be congenital or
acquired because of reasons like forceps deliveries in newborns and damage following radiation
therapy of jaws.
11. Hyperplasia of Mandibular Condyle
- Chronic mild inflammation may cause hyperplasia of condyle unilaterally causing
unilateral elongation of face and deviation toward the normal side.

20. Bibliography
Julian B. Woelfel and Rickne C. Scheid : Dental Anatomy: Its Relevance to Dentistry, 5th
Edition
Bertram S. Kraus : Kraus Dental Anatomy and Occlusion
P.R. Grant : Oral Cells and Tissue
Orban : Orban’s Oral Histology and Embryology
Nathan Allen Shore : Temporomandibular Joint Dysfunction & Occlasal
Equilibrium 2nd Edition
Henry Gray : Gray’s Anatomy
Richard Snell : Clinical Anatomy by Regions, 8th Edition
Robert E. Moyers : Handbook of Orthodontics
Ten Cate, A.R. : Oral Histology- Development, Structure, and
Function, 4th Edition