3. The efforts of the prosthodontist to record the movements of
the TMJ and to produce them on the articulator have been
the chief stimulus for studies on the functional structure of
this joint.
The purpose of this seminar is to focus attention on those
anatomic features which might provide a further basis for the
clinical management of the TMJ in prosthetic dentistry.
4.
5. Development of the human temporomandibular joint.
Mérida-Velasco JR1
, Rodríguez-Vázquez JF, Mérida-Velasco JA, Sánchez-Montesinos I, Espín-Ferra J,
Jiménez-Collado J. Anat. Res1 999 May 1;255(1):20-33.
A great deal of research has been published on the
development of the human temporomandibular joint
(TMJ). However, there is some discordance about its
morphological timing.
The most controversial aspects concern the moment of
the initial organization of the condyle and the squamous
part of the temporal bone, the articular disc and capsule
and also the cavitation and onset of condylar
chondrogenesis
A great deal of research has been published on the
development of the human temporomandibular joint
(TMJ). However, there is some discordance about its
morphological timing.
The most controversial aspects concern the moment of
the initial organization of the condyle and the squamous
part of the temporal bone, the articular disc and capsule
and also the cavitation and onset of condylar
chondrogenesis
6. In the last few decades a
considerable amount of
research has been published
on the development of the
temporomandibular joint
(Harpman and Woollard,
1938; Symons, 1952;
Moffett, 1957; Van Dongen,
1968; Perry et al., 1985).
Studies have focused on the
development of the articular
disc and its relation with the
7. Yuodelis, 1966a; Wong et al., 1985;
Smeele, 1990; Me
´ridaVelascoetal.,1993;O ¨ gu¨tcen-
TollerandJuniper, 1993, 1994); the
development of bony articular
elements (Baume, 1962; Yuodelis,
1966b; Baume and Holz, 1970;
Bach-Petersen et al., 1993);
8. Coleman, 1970; Smeele, 1988; Rodrı´guez Va´zquez et al.,
1992, 1993; O ¨ gu¨tcen-Toller,1995). However few of these
studies have attempted to systematize chronologically
the morphological changes taking place in the
temporomandibular joint during development.
Van der Linden et al. (1987) studied 52 human
embryos and fetuses, establishing the critical period
of TMJ morphogenesis between weeks 7 and 11 of
development
Moreover, MoMorimoto et al. (1987) describes a
number of phases in development
Development of the human temporomandibular joint.
Mérida-Velasco JR1
, Rodríguez-Vázquez JF, Mérida-Velasco JA, Sánchez-Montesinos I, Espín-Ferra J
, Jiménez-Collado J. Anat. Res1 999 May 1;255(1):20-33.
9. Three phases in the development of the
TMJ were identified.
The first is the blastematic stage
(weeks 7-8 of development), which
corresponds with the onset of the
organization of the condyle and the
articular disc and capsule.
During week 8 intramembranous
ossification of the temporal squamous
bone begins..
10. The second stage is the cavitation stage
(weeks 9-11 of development), corresponding
to the initial formation of the inferior joint
cavity (week 9) and the start condylar
chondrogenesis.
Week 11 marks the initiation of organization
of the superior joint cavity.
11. And the third stage is the maturation
stage (after week 12 of development). This
work establishes three phases in TMJ
development: 1) the blastematic stage (weeks
7-8 of development)
2) the cavitation stage (weeks 9-11 of
development)
3) the maturation stage (after week 12 of
development).
This study identifies the critical period of TMJ
morphogenesis as occurring between weeks 7
and 11 of development.
12.
13. The TMJ also known as cranio mandibular
joint is one of the complex, delicate and
highly used joints in a human body.
It is the area where mandible articulates
with cranium.
It is described as a
complex ,
compound,
multiaxial ,
synovial ,
Ginglimoarthroidal joint.
introduction
14. The area where the mandible
articulates with the cranium,
the TMJ, is one of the complex
joint in the body.
It provides hinging movement in
one plane and therefore can be
considered a ginglymoid joint.
However, at the same time it
also provides for gliding
movements, which classifies it
as arthroidal joint. Thus, it has
been technically considered as
ginglymoarthroidal joint.
15.
16. TMJ is classified as a compound joint.
By definition, a compound joint requires the
presence of at least three bones, yet the TMJ is
made of only two bones.
Functionally, the articular disc serves as a
nonossified bone that permits the complex
movements of the joint.
Because the articular disc functions as a third bone,
the craniomandibular articulation is considered a
Okeson, management of temporomandibular disorders and occlusion 6th
edition. Mosby
elsevier
17. Components of the
joint:
Articular surface of
the temporal bone
The Condyle
Articular disc/
Meniscus
Ligaments
18.
19. It is in the Sqamous portion of temporal
bone.
Consists of 3 parts:
Mandibular or glenoid fossa.
Articular eminence
Preglenoid plane.
Okeson. Management of temporomandibular disorder and
occlusion. 6th
edition. Elsevier mosby publication
20. It is the concave portion of the temporal
bone.
Boundaries:
Posteriorly: Squamotympanic or
Petrotympanic fissure
Medially: Spine of sphenoid
Laterally: Root of zygomatic process of
temporal bone
Anteriorly : Articular eminence
The glenoid fossa is covered by a dense, avascular
fibrocartilage consisting largely of bundles of
collagen fibres with occasional elastic fibres.
Okeson. Management of temporomandibular disorder and occlusion. 6th
edition.
Elsevier mosby publication
21. It is a small prominence on the
zygomatic arch.
It is thick and serves as functional
component of TMJ
On its lateral aspect, articular
tubercle is present which serves as
the point of attachment for the
collateral ligaments.
It is a cylindrical bony projection and
covered with a thin layer of fibro
cartilage.
22.
23. The mandible is a U shaped
bone that articulates with the
temporal bone by means of
the articular surface of its
condyle.
The head is covered with
fibrocartilage and articulates with
temporal bone to form TMJ.
Okeson. Management of temporomandibular disorder and
occlusion. 6th
edition. Elsevier mosby publication
24. In the normal joint, the articular
surface of the condyle is located
on the intermediate zone of the
disc.
The shape of the disc is
determined by the morphology
of the condyle and mandibular
fossa.
The disc is somewhat flexible
and can adapt to the functional
demands of the articular
surface.
Okeson. Management of temporomandibular disorder and
occlusion. 6th
edition. Elsevier mosby publication
25. Okeson 6th
edition. Elsevier mosby publication
From anterior view it has
medial and lateral
projections called poles
Medial pole is generally
more prominent then
lateral pole
Mediolateral length is
between 18 and 23mm
Anterioposterior width is
between 8 and 10 mm
26. The articular disc is composed of dense
fibrous connective tissue, for the most part
devoid of any blood vessels or nerve fibers.
The extreme periphery of the disc,
however, is slightly innervated.
In the sagittal plane, it can be divided into
three regions according to thickness :
intermediate, anterior, and posterior.
The central area is the thinnest and is
called the intermediate zone.
Wink CS, St Onge M, Zimny ML: Neural elements in the human temporomandibular articular disc, J Oral Maxillofac Surg 50:334-337, 1992.
27. In sagittal plane it is divided into 3 planes.
1. Anterior band
2. Intermediate band
3. Posterior band
28.
29. The disc becomes considerably thicker both
anterior and posterior to the intermediate
zone.
The posterior border is generally slightly
thicker than the anterior border.
In the normal joint the articular surface of
the condyle is located on the intermediate
zone of the disc, bordered by the thicker
anterior and posterior regions.
30.
31. Acts as cushion
Isolates synovial fluid
Divides joint cavity
Determinant in mandibular movement
32. The articular disc is attached posteriorly to a region
of loose connective tissue that is highly vascularized
and innervated .
This is known as the retrodiscal tissue or posterior
attachment.
Superiorly, it is bordered by a lamina of connective
tissue that contains many elastic fibers, the superior
retrodiscal lamina.
RETRODISCAL TISSUE
33.
34. The superior retrodiscal lamina attaches the articular
disc posteriorly to the tympanic plate.
At lower border of the retrodiscal tissues is the inferior
retrodiscal lamina, which attaches the inferior border of
the posterior edge of the disc( the posterior margin of
the articular surface the condyle.
Okeson. Management of temporomandibular disorder and occlusion. 6th
edition. Elsevier
mosby publication
35. The inferior retrodiscal lamina composed chiefly of
collagenous fibers, not elastic fibers like the
superior retrodiscal lamina.
The remaining body of the retrodiscal tissue is
attached posteriorly to a large venous plexus, which
fills with blood as the condyle moves forward.
The superior and inferior attachments of the
anterior region of the disc are to the capsular
ligament, which surrounds most of the joint. The
superior attachment is to the anterior margin of the
articular surface of the temporal bone.
36. The inferior attachment is to the anterior margin
of the articular surface of the condyle.
Both these anterior attachments are composed
of collagenous fibers. Anteriorly, between the
attachments of the capsular ligament, the disc is
also attached by tendinous fibers to the superior
lateral pterygoid muscle.
37.
38. Ligaments associated with the TMJ are composed of
collagen, which do not stretch and act
predominantly as restraints to motion of the condyle
and the disc.
They play an important role in protecting the
structures of the joint.
The TMJ has support of 3 functional ligaments and 2
accessory ligaments.
39. • Functional ligaments- Serve as major anatomical
component for the joint.
a] Collateral/Discal ligament
b] Capsular ligament
c] Temporomandibular ligament
• Accessory ligaments-Serve as passive restraints to
mandibular motion.
a] Sphenomandibular ligament.
b] Stylomandibular ligament.
40. COLLATERAL/DISCAL
ATTACHMENTS
These ligaments attach the articular disc to
the medial and lateral poles of the
condyle.
These are called the discal ligaments.
These are composed of collagenous
connective tissue fibers and they do not
stretch.
They function to restrict the movement of
the disc away from the condyle and permit
the disc to rotate anteriorly and posteriorly
on the condyle.
41. • The capsule of TMJ is described as fibrous
non elastic membrane surrounding the
joint.
• The capsule seals the joint and provides
passive stability.
• The active stability is achieved by
proprioceptive nerve endings in the
capsule which resist medial, lateral and
inferior forces thereby holding the joint
together.
• It offers resistance to movement of joint
only in the extreme range of motion.
• Secondary function of the capsular
ligament is to contain the synovial fluid
within the superior and inferior joint
spaces.
42. • It is located on the lateral
aspect of each TMJ.
• This ligament runs
downwards and
backwards from the
lateral aspect of the
articular eminence to the
posterior aspect of the
neck.
Okeson 6th
edition, elsevier. Mosby publication
43. Its function is to
limit the posterior
movement of the
condyle during
pivoting
movements such as,
when the mandible
moves laterally in
chewing position.
It also protects the
inner lateral
pterygoid muscle
from over
lengthening or
extension.
44. • The sphenomandibular
ligament arises from the
spine of the sphenoid
and extends downwards to a
small bony prominence on
the medial aspect of the
mandible called the lingula.
• It does not have any limiting
function on TMJ.
• It is a remnant of Meckels
cartilage.
• It assists the lateral pterygoid
in translatory and rotatory
movement.
45. • It arises from the styloid
process and extends
downwards and forwards to
the angle and posterior
border of the ramus of the
mandible.
• It limits the protrusive
movement of the mandible.
• It is taut in protrusion of
the mandible and relaxed
when the mandible is wide
opened.
46.
47. The muscles of mastication are directly concerned
with mandibular movements in mastication and
speech.
4 pairs of muscles make up a group called the
muscles of mastication.
1. Masseter
2. Temporalis Accessory muscles
3. Medial pterygoid 1. Buccinator
4. Lateral pterygoid 2. Digastricus.
48.
49. These four pairs of muscles attached to mandible,
primarily responsible for
Elevating
Depressing
Protruding
Retruding
Lateral movement
50.
51. It is a quadrilateral muscle.
The fibers are arranged in3 layers
Superficial layer:
Origin : anterior 2/3 of inferior
surface of zygomatic arch.
& maxillary process of
zygomatic arch.
Insertion: angle of mandible ,
posterior half of the lateral
surface of mandibular
ramus.
Orbans
52. Middle layer:
Origin: medial aspect of 2/3 of
zygomatic arch.
Insertion: middle part of ramus.
Deep layer:
Origin: deep surface of zygomatic
arch.
Insertion : upper part of ramus &
coronoid process.
Most powerful closing muscle of
jaw
53.
54. Action :
Elevates the mandible
to close the mouth.
Retraction of mandible
& clenching of teeth.
Superficial fibers help
in protrusion of
mandible.
55. This is a fan
shaped muscle
and fills the
temporal fossa.
The temporal
fascia covers the
muscle.
56. Origin:
Temporal fossa &
deep surface of
temporal fascia
Insertion:
Fibers converge to
insert on tip &
medial surface of
coronoid process of
mandible and
anterior border of
ramus of mandible
58. It is a quadrilateral
muscle with 2 heads.
A small superficial
head & a large deep
head.
59. Origin:
Superficial head: from
maxillary tuberosity
and adjoining
pyramidal process of
palatine bone.
Deep head: larger,
arises from medial
surface of lateral
pterygoid.
Insertion:
The fibres run
downwards, backwards
& laterally to insert
into medial surface of
the angle and
adjoining part of
ramus of mandible.
60.
61. Actions:
When both side muscle
contracts together it
elevates the mandible
When one side muscle
contracts jaw is pulled to
opposite side.
It also helps in protrusion
of the mandible and helps
in lateral movements of the
jaw.
62. It is a short and
thick muscle with 2
distinct heads.
63. Origin:
Upper head- small, arises
from infra temporal
surface of greater wing of
sphenoid.
Lower head – large, arises
from lateral surface of
lateral pterygoid plate.
Insertion:
Fibres run backwards,
laterally, converge to insert
into pterygoid fovea in the
anterior surface of neck of
mandible, adjoining
articular disc and capsule
of TMJ.
64. Actions:
Depresses the mandible.
Lateral and medial pterygoid
muscles of both sides act
together to protrude the
mandible.
Helps in side to side movements
of the jaw.
65. Temporalis, masseter, medial pterygoid muscle elevates
the jaw and have great power in keeping the teeth
clenched.
The mouth opens by relaxation of these muscle and by
weight of mandible coordinated with contraction of
suprahyoid and infrahyoid group of muscle, platysma
and lateral pterygoid muscle.
Infrahyoid and suprahyoid muscle also helps in function
of degluttination, phonation and mastication.
66.
67.
68. Histology of the Articular Surfaces
The articular surfaces of the mandibular condyle and
fossa are composed of four distinct layers or zones
(1) articular,
(2) proliferative,
(3) fibrocartilaginous and
(4) calcified cartilage
69.
70. Articular surfaces of condyle and mandibular fossa
composed of 4 layers or zones
Most superficial layer is articular zone
Outermost functional surface
Made up of dense fibrous connective tissue
Collagen fibers are arranged in bundles and tightly
packed and so can withstand forces
Second zone is proliferative zone and is cellular
Undifferentiated mesenchymal tissue
Proliferation of articular cartilage is responsible to
functional demands
71. Third zone is fibrocartilaginous zone
Collagen fibrils arranged in bundles in crossing
pattern
Offers resistance against compressive and lateral
forces
Fourth and deepest zone is calcified
zone
Made up of chondrocytes and chondroblasts
Site for bone remodeling activity.
External pressure resulting from joint loading
is in equilibrium with internal pressure of
articular cartilage
76. Two mechanisms of the lubrication :
• Boundary lubrication
Prevents friction in the moving joint
• Weeping lubrication
Eliminates friction in the compressed but not moving
joint
77. Auriculotemporal nerve
Deep temporal nerve
Masseteric nerve
Four types of nerve endings –
• Ruffini endings
• Pacini corpuscles
• Golgi tendon organ
• Free nerve endings
78. The Ruffini’s corpuscles, present in the
capsule are the proprioceptors and
sense the changes in the joint when the
joint is static.
The pacinian corpuscles, also present
in the capsule, act as
mechanoreceptors to signal the rapidity
and slowness of the joint movement.
79. The Golgi tendon, present in the TM
joint ligament, functions as a
mechanoreceptor to protect the joint
when joint movements become
excessive.
The free nerve endings which are
nociceptors (receptors for pain), are the
most numerous and widely distributed;
protect the joint from excessive
movements by causing pain.
81. Described by Tanasesco (1912)
lymph node is an oval-shaped organ of the lymphatic
system, distributed widely throughout the body.
Lymph nodes are major sites of B, T, and other immune
cells.
Lymph nodes are important for the proper functioning of the
immune system, acting as filters for foreign particles
The lymph from temporo mandibular joints is drained into:
• Superficial parotid nodes
• Deep parotid nodes
•Upper deep cervical nodes
82.
83.
84.
85. The thinness of the bone in the
articular fossa is responsible for
fractures if the mandibular head is
driven into the fossa by a heavy blow.
In such cases injuries of the dura
mater and the brain have been
reported.
86. The finer structure of the bone and its
fibrocartilaginous covering depends on mechanical
influences.
A change in force or direction of stress, especially
after loss of posterior teeth, may cause structural
changes.
These changes may include fibrillation (separation
between collagen bundles) of the fibrous covering of
the articulating surfaces and of the disk.
Abnormal functional activity may also produce injury
to the articular bones
87. In severe trauma the articular bone is
destroyed, and cartilage and new bone
develop in the marrow spaces and at
the periphery of the condyle.
When this occurs, the function of the
joint is severely impaired
88. The articular surface is capable of
remodeling due to functional demands.
It shows changes due to loss of teeth or
due to attrition of teeth.
It also gets remodeled due to
orthodontic treatment.
89. Normally, in the open position of the
mandible the interincisal distance is
approximately 48 mm in males and
45.5 mm in females.
In approximately 18% of the population
the mandible deviates on opening, and
in almost 86% of this group deviation is
to the left.
In approximately 35% of the population
the TMJ produces sounds during
opening movements.
Gross A and Gale EN: A prevalence study of the clinical signs associated with
mandibular dysfunction. J Am Dent Assoc 107:932, 1983.
90. The joint has palpable irregularities
and produces popping and clicking
noises.
However, use of a stethoscope reveals
that approximately 65% of TMJs
produce some kind of sound.
This feature by itself, especially if not a
sign of disease may not require
treatment.
91. The term myofacial pain dysfunction
syndrome is used to indicate a
dysfunction of the TMJ.
It is characterized by:
(1) masticatory muscle tenderness
(most frequently, the lateral pterygoid
and then, in order, the temporalis,
medial pterygoid, and masseter);
(2) limited opening of the mandible (<
37 mm); and
92. (3) joint sounds. This symptom complex
is seen more often in females than in
males.
Its cause is usually spasm of the
masticatory muscles.
Since the condition may be related to
stress, treatment should be as
conservative as possible.
93.
94. Dislocation of the TMJ may take place
without the impact of an external force.
The dislocation of the jaw is usually
bilateral, and the displacement is
anterior.
When the mouth is opened unusually
wide during yawning, the head of the
mandible may slip forward into the
infratemporal fossa, causing articular
dislocation of the joint.
95. Recently diagnostic techniques such as
computerized tomography (CT) and
magnetic resonance imaging (MRI),
which permit the visualization of the
TMJ disks in patients, are being applied
increasingly in the diagnosis of internal
disk dislocation or derangement.
96. The disk, for reasons not yet
determined, becomes displaced
anteromedially and creates one or more
of the following signs and symptoms:
pain,
clicking,
limitation of jaw movement,
deviation of the jaw or opening,
and locking.
If the condition remains untreated, it
could lead to osteoarthrosis.
97. Diagnosis of cases of the TMJ disk
perforation is also on the increase, partly
because of the use of arthroscope, MRI, and
arthrographic techniques in the investigation
of TMJ diseases.
Recently research has shown that
experimentally produced disk perforation in
rhesus monkeys leads to secondary
osteoarthrosis.
Consequently, treatment of human disk
perforation will require more serious
consideration than it receives at present
Toller PA: Opaque arthrography of the temporomandibular joint. Int J Oral Surg 3:17,
1974.
98. A good prosthodontic treatment bears direct
relation with TM articulation since establishment of
occlusion is one of the main step in complete
denture, fixed partial & removal partial dentures.
A thorough knowledge of TMJ & its relationship with
surrounding structures is essential to fully
comprehend normal anatomy & physiology,
adaptive processes, dysfunction & pathology of the
TMJ.
99. Wink CS, St Onge M, Zimny ML: Neural elements in the human
temporomandibular articular disc, J Oral Maxillofac Surg
50:334-337, 1992.
Development of the human temporomandibular
joint.Mérida-Velasco JR1
, Rodríguez-Vázquez
JF, Mérida-Velasco JA, Sánchez-Montesinos I, Espín-
Ferra J, Jiménez-Collado J. Anat. Res1 999 May
1;255(1):20-33.
Okeson 6th
edition. Elseiver mosby publication.
Orbans oral histology and embryology. 13th
edition.
Elsevier.
Toller PA: Opaque arthrography of the temporomandibular joint.
Int J Oral Surg 3:17, 1974.
