Anatomy of temporomandibular joint Anatomy and physiology of temporomandibular joint

1. ANATOMY &
PHYSIOLOGY OF
TMJ
PRESENTED BY:
DR. KAMINI DADSENA
New horizon Dental college & research institute Bilaspur Chhattisgarh.

2. OUTLINE
1. Introduction
2. Development, Anatomy & Physiology of TMJ
3. Clinical & radiographic evaluation
4. Classification of TMJ disorder
5. Surgical anatomy & approaches to TMJ
6. Autogenous and Alloplastic Joint Replacement
7. Postoperative physical therapy
8. Success, failure and Complication of TMJ surgery
9. Summery and Conclusion
10.Bibliography

3. “Nothing is more fundamental
to treating patients than
knowing the anatomy.”
—Jeffrey P. Okeson

4. INTRODUCTION:
 The temporomandibular joint is a synovial
joint between the mandibular fossa of
squamous part of the temporal bone above
and the mandibular condyle below.

5. DEVELOPMENTAL ANATOMY:
 The temporomandibular joint is a secondary
development in both evolutionary (phylogenetic) and
embryological (ontogenetic) history.
 The joint between the malleus and incus that develops
at the dorsal end of Meckel’s cartilage is
phylogenetically the primary jaw joint and is
homologous with the jaw joint of reptiles.

9. TMJ COMPONENTS:

10. CAPSULE

11. CLINICAL SIGNIFICANCE:
 Medially spine of sphenoid, sphenomandibular
ligament and middle meningeal artery are closely
related to medial capsule.
 Between the posterior capsule and post glenoid
tubercle, a highly vascular tissue called the vascular
body is found.
 Parotid tissue is usually found between the posterior
capsule and post glenoid tubercle.
 During the surgical exposure through a preauricular
approach, surgeon should protect the temporal
branch of facial nerve.
 Incising and reflecting the capsule usually lead to the
cutting of nerve fibres, which may result in post
operative analgesia and relief from pain.

12. EXTRACAPSUAR LIGAMENTS:
 Three functional ligaments support the TMJ:
(1) the collateral ligaments
(2) the capsular ligament, and
(3) the temporomandibular (TM) ligament.
 Two accessory ligaments also exist:
(4) the sphenomandibular and
(5) the stylomandibular
(6) pterygomandibular ligament

14. The collateral ligaments
 The collateral ligaments attach the medial and
lateral borders of the articular disc to the poles of the
condyle.
 The medial discal ligament attaches the medial
edge of the disc to the medial pole of the condyle.
The lateral discal ligament attaches the lateral edge
of the disc to the lateral pole of the condyle.
 These ligaments are responsible for dividing the joint
mediolaterally into the superior and inferior joint
cavities.

15. function
 They function to restrict movement of the disc away
from the condyle. In other words, they allow the disc
to move passively with the condyle as it glides
anteriorly and posteriorly.
 The attachments of the discal ligaments permit the
disc to be rotated anteriorly and posteriorly on the
articular surface of the condyle. Thus these ligaments
are responsible for the hinging movement of the TMJ,
which occurs between the condyle and the articular
disc.
 The discal ligaments have a vascular supply and are
innervated. Their innervation provides information
regarding joint position and movement. Strain on
these ligaments produces pain.

16. Capsular Ligament
FUNCTION:
 The capsular ligament acts to
resist any medial, lateral, or
inferior forces that tend to
separate or dislocate the
articular surfaces.
 It encompass the joint, thus
retaining the synovial fluid.
 The capsular ligament is well
innervated and provides
proprioceptive feedback
regarding position and
movement of the joint.

17. TM LIGAMENT:
 The lateral aspect of
the capsular ligament is
reinforced by strong,
tight fibres that make
up the lateral ligament,
or TM ligament.
 The TM ligament is
composed of two
parts,
1. an outer oblique
portion and
2. an inner horizontal
The OOP limits normal rotational
opening movement; the IHP limits
posterior movement of the condyle
and disc.

18.  The oblique portion of the TM ligament resists
excessive dropping of the condyle, therefore
limiting the extent of mouth opening. This portion of
the ligament also influences the normal opening
movement of the mandible.
 During the initial phase of opening, the condyle
can rotate around a fixed point until the TM
ligament becomes tight as its point of insertion on
the neck of the condyle is rotated posteriorly.
 When the ligament is taut, the neck of the condyle
cannot rotate further. If the mouth were to be
opened wider, the condyle would need to move
downward and forward across the articular
eminence impingement.

19. Sphenomandibular ligament:
 At its upper end, the
ligament is crossed by
chorda tympani nerve.
 It represents one of the
embryonic remnant of
meckel’s cartilage.
 Recently loughner and
colleague found after gross
anatomic dissection of 14
head that SML has no
connection to medial
capsule of the TMJ and
there fore has no
significance to the
biological mechanism of
joint.

20. Stylomandibular ligament:
 It arises from the styloid
process and extends
downward and forward to
the angle and posterior
border of the ramus of the
mandible.
 It becomes taut when the
mandible is protruded but
is most relaxed when the
mandible is opened. The
stylomandibular ligament
therefore limits excessive
protrusive movements of
the mandible.

21. Pterygomandibular ligament:
 Attaches to pterygoid hamulus above and to the
posterior end of mylohoid ridge of the mandible
beow.

22. ARTICULAR EMNENCE:
 The articular eminence consist of
1. Descending slope
2. Transverse ridge
3. Ascending slope

23. GLENOID FOSSA:
 The glenoid fossa is limited
posteriorly by the petrotympanic
fissure, which provides attachment
to the posterior capsule and limit
the boundary of the posterior
recess of joint of the joint cavity.
 The fossa has lateral and medial
rims.
 The media rim is just lateral to the
spine of the sphenoid bone and
foramen spinosum with middle
meningeal artery.
 Lateral rim continues anteriorly into
the zygomatic tubercle , which can
be felt under the skin, and
posteriorly into the postglenoid
tubercle.

24. CONDYLE:
 mediolateral length 18 and 23mm,
 anteroposterior width 8 and 10 mm.
 The posterior articulating surface is greater than the anterior
surface.
 The articulating surface of the condyle is quite convex
anteroposteriorly and only slightly convex mediolaterally.

25. DISK:
 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:
1. intermediate zone- central area, thinnest
2. Anterior attachment
3. Posterior attachment: thicker than ant.
 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.

26. SYNOVIAL MEMBRANE:
 The internalsurfaces of the cavities are surrounded by
specialized endothelial cells that form a synovial lining.
 This lining, along with a specialized synovial fringe
located at the anterior border of the retrodiscal
tissues, produces synovial fluid, which fills both joint
cavities

27. Contents of synovial fluid-
 Cells – monocytes, lymphocytes, free
synovial cells & ocassionally PMNs.
 Chemical comp.- Hyaluronate is a GAG –
gives viscosity to the synovial fluid –draws
water & salts to the cavity to give an
extracellular fluid comp.
Purpose of synovial fluid-
 Lubrication – reduces friction between
surfaces.
 Meets Metabolic requirements of the
avascular articular surfaces.

28. Mechanism of lubrication – 2
1. BOUNDARY LUBRICATION –
- synovial fluid is located at the borders
or the recess areas –it is forced from
one area of the cavity to another
when the joint moves.
- Prevents friction in the moving joint.
- Primary mechanism of joint lubrication.

29. 2. WEEPING LUBRICATION-
- Articular surfaces absorb some amount of
synovial fluid.
- During function – compressive forces
created drive out small amt. of fluid in &
out of the articular surfaces.
- It is the mechanism of metabolic
exchange.
- Also prevents sticking of the articulating
surfaces – hence, it eliminates friction
during compression but not moving joint.
- Prolonged compressive forces will exhaust
this supply.

30. ANATOMIC RELATION OF TMJ

31. Superficial relations
 Covered by – skin,
superficial fascia &
branches of the facial
nerve.
 Auriculotemporal nerve
– passes through the
fascia
 Glenoid lobe of parotid
gland.

32. Superior relations
 Roof of mandibular fossa – seperates
TMJ from middle cranial fossa &
temporal lobe of brain
 Tympanic cavity – medio-superior &
slightly posterior to the joint
 Chorda tympani nerve & Anterior
ligament of Malleus – pass through
squamotympanic fissure – medio-
superior to the joint.

33. Inferior relation
 Parotid gland – seen in relation to lateral,
posterior & medial side of ramus & neck of
mandible.- small wedge shaped medial
projection of the gland lies posterior &
inferior to condylar head.
 Inferior lateral pterygoid – passes postero-
laterally from pterygoid plates to the
pterygoid fovea.
 Numerous venous channels- inferior to
condylar neck
 Pterygoid venous plexus- between
pterygoid muscles & between these muscles
& cranial base

34. Anterior relation
 Lateral pterygoid
muscle.
 Massetric & deep
temporal nerves – pass
in between lateral
pterygoid muscle &
inferior surface of
temporal bone.

35. Posterior relation
 Auriculo-temporal nerve – passes posteriorly
to condylar neck- comes in close
association with superficial temporal artery &
transverse facial artery.
 Part of parotid – between cartilagenous &
bony part of external auditory meatus & the
joint
 Styloid process – posterior & medial to the
joint.

36. Medial relations
 Medial capsule of the joint- attached to
squamotympanic fissure & continious with Anterior
Ligament Of Malleus.
 Spine of sphenoid with the origin of Sphenomandibular
Ligament
 Chorda tympani nerve – emerges from its bony canal to
groove medial side of spine of sphenoid
 Auriculotemporal nerve arises from posterior division of
mandibular nerve- its 2 roots embrace the middle
meningeal artery, unite to form a single trunk – passes
posteriorly to condylar neck

37. INNERVATION OF THE TMJ
 TMJ receives innervation primarily from
1. Auriculotemporal nerve
 With contribution from
1. Massetric
2. Deep temporal nerve

38. Receptors Type Ass. Nerve fibers
Free
nerve
endings
Nociceptive Small myelinated (A-
delta) & unmyelinated
(C) fibers
Ruffini or
Meissner
corpuscle
s
Low threshold,
slowly adapting-
Mechanoreceptor
Large myelinated A-beta
fibers
Pacinian
corpuscle
s
Low threshold,
rapidly adapting
mechanoreceptor
Large myelinated A-beta
fibers
Golgi
type
endings
High threshold,
very slowly
adapting
mechanoreceptor
Large myelinated A-
alpha fibres

39. VASCULARIZATION OF THE TMJ
1. Superficial temporal
2. Internal maxillary
3. Deep auricular
4. Anterior tympanic

40. HISTOLOGY OF ARTICULAR
SURFACE:

42.  GRAY’S ANATOMY 40TH Ed
 CRANIOFACIAL DEVELOPMENT : Geoffrey H. Sperber

43. THANK YOU