This document provides an overview of the temporomandibular joint (TMJ), including its classification, development, anatomy, biomechanics, innervation, and surgical approaches. Key points covered include that the TMJ is a synovial joint that connects the mandible to the skull and allows for hinge and gliding movements. It has several unique features, such as having an articular disc and fibrocartilage surfaces. The document describes the anatomy of the TMJ in detail, including the mandibular fossa, condyle, articular disc, ligaments, vascular supply, and innervation. Finally, common surgical approaches to access the TMJ are summarized.

1. Seminar presented by
Dr. Mehul Shashikant Hirani
First Year Junior Resident
Dept. of Oral & Maxillofacial Surgery
FDS, IMS, BHU, Varanasi

2. CONTENTS
 INTRODUCTION
 CLASSIFICATION OF JOINT
 DEVELOPMENT OF TMJ
 MANDIBULAR FOSSA
 CONDYLE
 ARTTICULAR DISC
 INNERVATION
 VASCULAR SUPPLY
 LIGAMENTS
 BIOMECHANICS
 SURGICAL APPROACHES

3. INTRODUCTION
 The Temporomandibular Joint is the one
which connects the mandible to the skull
and regulates mandibular movements
 It is a bicondyler joint in which the
condyles ,located at the ends of
mandible, function at the same time.
 The right & left TMJ form Bicondylar
Articulation and Ellipsoid variety of
synovial joints similar to Knee joint.

4.  TMJ is GINGLIMOARTHRODIAL joint
Ginglymus - Hinge, allowing motion only
forward and backward in one plane.
Arthrodia - Joint which permits gliding
movements of surfaces.
 The common features of synovial Joint
exhibited by this joint includes a disk, bone,
fibrous capsule, fluid, synovial membrane
and ligaments. However, TMJ is unique in
a way that the articular surface is made of
Fibrocartilage instead of Hyaline cartilage
as seen in other synovial joints.

5. PECULIARITY OF TMJ
1. Bilateral diarthrosis – right & left
function together
2. Articular surface covered by
Fibrocartilage – instead of Hyaline
cartilage
3. Only joint in the body to have a Rigid
endpoint of closure ( that of teeth
making occlusal contact )
4. Has 4 articular surfaces.

6. 5. In contrast to other diarthrodial joints TMJ is
the last joint to start developing –in about 7th
week in utero
6. Develops from two distict blastema
i) temporal
ii) condylar
7. TMJ acts like Class III Lever

7. Development Of TMJ
 The TMJ develops from
mesenchyme lying between
developing mandibular
condyle below and the bone
above, which develops
intramembranously.
 During the 12th week of IU
life, 2 clefts appear in the
mesenchyme – producing
upper and lower joint
cavities.

8.  The remaining intervening mesenchyme
becomes the Intra articular disc.
 The joint capsule develops from a
condensation of mesenchyme
surrounding the developing joint.
 Mandibular Fossa is flat at birth and
there is no articular eminence, this
becomes prominent only following the
eruption of the deciduous dentition.

9. Mandibular/ Glenoid Fossa
Bounderies-
 Anterior aspect of articular
eminence
 Posterior non articular fossa is
part of squamous temporal bone
& formed by tympanic plate (
Forms anterior bony wall of
external Acoustic meatus )

10. ARTICULAR EMINENCE
 This is the entire transverse bony bar that
forms the anterior root of zygoma.
 This articular surface is most heavily traveled
by the condyle and disk as they ride forward
and backward in normal jaw function.
ARTICULAR TUBERCLE
 This is a small, raised, rough, bony knob on
the outer end of the articular eminence.
 It projects below the level of the articular
surface and serves to attach the lateral
collateral ligament of the joint.

11. PREGLENOID PLANE
 This is the slightly hollowed, almost
horizontal, articular surface continuing
anteriorly from the height of the articular
eminence

12. E: Articular eminence;
enp: entogolenoid
process;
t:articular tubercle;
lb: lateral border of the
mandibular fossa;
pep: preglenoid
plane;
Gf: glenoid fossa

13. MANDIBULAR CONDYLE
 An ovoid process seated atop a narrow
mandibular neck.
 It’s the articulating surface of the mandible.
 It is convex in all directions but
wider medio-laterally (15 to 20mm)
than antero-posteriorly (8 to10mm).
 It has a medial and lateral pole.The medial
pole is directed more posteriorly.

14. Mainly 4 forms are
seen-
1. Convex-58%
2. Flat- 25%
3. Pointed-12%
4. Round- 3%
( mainly in children)

15. If the long axes of two
condyles are extended
medially, they meet at
approximately the basion
on the anterior limit of the
foramen magnum, forming
an angle that opens
toward the front ranging
from 145° to160°

16.  The lateral pole of the condyle is
rough, bluntly pointed, and
projects only moderately from the
plane of ramus, while the medial
pole extends sharply inward from
this plane.
 The articular surface lies on its
anterosuperior aspect, thus facing
the posterior slope of the articular
eminence of the temporal bone.

17. ARTICULAR DISC

18.  Biconcave fibro cartilaginous structure
located between the mandibular condyle and
the temporal bone component of the joint.
 Functions to accommodate a hinging action
as well as the gliding actions between the
temporal and mandibular articular bone
 Is avascular and aneural in its central part but is
vascular and innervated in the peripheral areas,
where load-bearing is minimal
 The main load-bearing areas are located on the
lateral aspect; this is an area of potential
perforation
 Merges around its periphery, attaching to the
capsule

19.  The articular disc is a roughly oval, firm, fibrous plate.
1. anterior band = 2 mm in thickness,
2. posterior band = 3 mm thick,
3. thin in the center intermediate band of 1 mm
thickness.
 More posteriorly there is a bilaminar or retrodiscal
region.
Anterior Band
Posterior Band
Retrodiscal Tissue

20. Located posterior to the articular disc
Highly distortable, especially on opening the mouth
Composed of:
● Superior lamina—contains elastic fibers and anchors
the superior aspect of the posterior portion of the disc
to the capsule and bone at the postglenoid tubercle
and tympanic plate
● Retrodiscal pad—the highly vascular and neural
portion of the TMJ, made of collagen, elastic fibers,
fat, nerves, and blood vessels (a large venous plexus
fills with blood when the condyle moves anteriorly)
● Inferior lamina—contains mainly collagen fibers and
anchors the inferior aspect of the posterior portion of
the disc to the condyle
Bilaminar zone (posterior attachment complex)

21. TMJ compartments
 The articular disc divides the TMJ into superior
and inferior compartments
 The internal surface of both compartments
contain specialized endothelial cells that form
a synovial lining that produces synovial fluid,
making the TMJ a synovial joint
 Synovial fluid acts as:
A lubricant
An instrument for providing the metabolic
requirements to the articular surfaces of the
TMJ

22. Superior Compartment
 Between the squamous
portion of the temporal
bone and the articular disc
 Volume = 1.2mL
 Provides for the
translational movement
of the TMJ
Inferior Compartment
 Between the articular disc
and the condyle
 Volume = 0.9mL
 Provides for the rotational
movement of the TMJ
Open mouth,
Sagittal section of TMJ

23. CAPSULE
 Completely encloses the articular surface of the temporal
bone and the condyle
 Composed of fibrous connective tissue
 Toughened along the medial and lateral aspects by
ligaments
 Lined by a highly vascular synovial membrane
 Has various sensory receptors including nociceptors
Attachments:
● Superior—along the rim of the temporal articular surfaces
● Inferior—along the condylar neck
● Medial—blends along the medial collateral ligament
● Lateral—blends along the lateral collateral ligament
● Anterior—blends with the superior head of the lateral
pterygoid muscle
● Posterior—along the retrodiscal pad

24. LIGAMENTS
Collateral Ligaments
 Composed of 2 ligaments:
Medial collateral ligament—connects the medial
aspect of the articular disc to the medial pole
of the condyle
Lateral collateral ligament—connects the lateral
aspect of the articular disc to the lateral pole
of the condyle
● Frequently called the discal ligaments
● Composed of collagenous connective tissue;
thus, they do not stretch

25. LATERAL VIEW
JOINT CAPSULE
LATERAL LIGAMENT
SPHENOMANDIBULAR LIGAMENT
STYLOID PROCESS
STYLOMANDIBULAR LIGAMENT

26. Temporomandibular (Lateral) Ligament
● The thickened ligament on the lateral aspect of
the capsule
● Prevents lateral and posterior displacement of the
condyle
● Composed of 2 separate bands:
 Outer oblique part—largest portion; attached to
the articular tubercle; travels posteroinferiorly to
attach immediately inferior to the condyle; this
limits the opening of the mandible
 Inner horizontal part—smaller band attached to
the articular tubercle running horizontally to
attach to the lateral part of the condyle and disc;
this limits posterior movement of the articular disc
and the condyle

27. Stylomandibular Ligament
● Composed of a thickening of deep
cervical fascia
● Extends from the styloid process to the
posterior margin of the angle and the
ramus of the mandible
● Helps limit anterior protrusion of the
mandible
Sphenomandibular Ligament
● Remnant of Meckel’s cartilage
● Extends from the spine of the sphenoid
to the lingula of the mandible
● May help act as a pivot on the mandible
by maintaining the same amount of
tension during both opening and closing
of the mouth

28. ARTERIAL SUPPLY
ANTERIOR TYMPANIC
ARTERY
MAXILLARY ARTERY
DEEP AURICULAR
ARTERY
POSTERIOR
AURICULAR
ARTERY
EXTERNAL
CAROTID ARTERY
SUPERFICIAL
TEMPORAL ARTERY

29. Artery Source Course
SUPERFICIAL
TEMPORAL
Terminal branch of
EXTERNAL CAROTID
ARTERY
Begins in the parotid gland and
initially is located posterior to the
mandible, where it provides small
branches to the TMJ
DEEP AURICULAR MAXILLARY ARTERY Arising in the same area as that
of the anterior tympanic artery
Lies in the parotid gland,
posterior to the TMJ, where it
gives branches to the TMJ
ANTERIOR
TYMPANIC
Arising in the same area as that
of the deep auricular artery.
Passes superiorly behind the
TMJ to enter the tympanic
cavity through the petrotympanic
fissure, where it gives
branches to the TMJ

30. VENOUS DRAINAGE
VEIN COURSE
SUPERFICIAL TEMPORAL Receives some branches from the TMJ
Then joins the maxillary vein to form the
retromandibular vein
MAXILLARY Receives some branches from the TMJ
Joins the superficial temporal vein to
form the retromandibular vein

31. SENSORY
INNERVATION
MANDIBULAR NERVE
& OTIC GANGLIONAURICULOTEM
PORAL NERVE
INFERIOR
ALVEOLAR
NERVE
LINGUAL NERVE
MAXILLARY
ARTERY

32. NERVE SOURCE COMMENT
AURICULOTEM
PORAL
MANDIBULAR DIVISION
OF TRIGEMINAL NERVE
From the posterior division of the mandibular
division of the trigeminal nerve.
Splits around the middle meningeal artery
and passes between the sphenomandibular
ligament and the condylar neck.
Supplies sensory branches all along the
capsule.
Sensory but carries autonomic function to the
parotid Gland.
MASSETERIC ANTERIOR DIVISION OF
MANDIBULAR DIVISION
OF TRIGEMINAL NERVE
Lies anterior to the TMJ and provides
branches to the joint before passing over the
masseteric notch to reach the masseter
muscle.
Sensory branches aid the auriculotemporal
nerve.
POSTERIOR
DEEP
TEMPORAL
Lies anterior to the TMJ and provides
branches to the joint before innervating the
temporalis muscle.
Sensory branches aid the auriculotemporal
nerve in supplying the anterior part of the
TMJ.
Mainly motor, but carries additional sensory
function to the TMJ

33. JOINT MOVEMENTS
 Rotational / hinge movement in first 20-
25mm of mouth opening
 Translational movement after that when
the mouth is excessively opened.
 Translatory movement – in the superior
part of the joint as the disc and the
condyle traverse anteriorly along the
inclines of the anterior tubercle to
provide an anterior and inferior
movement of the mandible

35.  Hinge movement – the inferior portion of
the joint between the head of the
condyle and the lower surface of the
disc to permit opening of the mandible.
WIDE OPEN
HINGE + GLIDING
SLIGHT OPEN
HINGE PREDOMINATES

36. SURGICAL APPROACHES

37.  Preauricular :
Dingman’s, Blair’s, Thoma’s, Al-kayat and
Bramley’s, Popowitch’s
 Postauricular .
 Endaural approach
 Post ramal/ Hind’s approach
 Submandibular/Risdon’s approach
 Hemicoronal
 Bicoronal
 Rhytidectomy approach

38. PREAURICULAR
APPROACH
 Basic incision given
by Dingman(1951)
 Most basic &
standard approach
to TMJ.

39. MODIFICATIONS OF
PREAURICULAR APPROACH
 Blair & Ivy (1936) –
“Inverted hockey stick “
incision.
 Facilities exposure of
arch along with
condylar area.

40.  Thoma in 1958
 Angulated vertical
incision.
 Carried out across
zygomatic arch
infront of ear to
avoid main trunk of
facial nerve

41. AL-KAYAT & BRAMLEY
APPROCH
 1979.
 Modified preauricular
approach.
 Facial nerve divides in
front of auditory canal as
near as 0.8cm & as far
as 3.5cm
 Protection achieved by
making incision through
temporal fascia &
periosteum down to arch
not more than 0.8 cm.

42. POST – AURICULAR
APPROACH
 Hoops et al (1970),
 Alexander and
James (1975)
 Highly cosmetic
incision
 Disadvantage- poor
access & visibility, the
risk of external
auditory meatus
stenosis, infection &
deformity of the
auricle.

43.  Lempart (1938)
 Short facial skin
incision extending in to
external Auditory
meatus
 Excellent cosmetics
 Disadvantage-Meatal
stenosis or chondritis,
injury to the branches
of the facial nerve
END AURAL Approach

44. Post Ramal / Hind’s Approach
 Indication – surgeries of
condylar neck & ramus
area.
 Incision- 1cm behind
ramus of mandible and
extends 1cm below the
lobe of ear.
 Highly cosmetic, excellent
visibility and accessibility.
 Injury may occur to
posterior facial vein and
main trunk of facial nerve.

45. Submandibular Risdon
Approach
 Risdon (1934)
 Mainly used for
neck of condyle &
ramus region.
 Supplement to
different TMJ
approaches for
tunneling through
the soft tissues to
place a graft

46. Coronal Approach
 Hemicoronal (unilateral) or bicoronal
(bilateral) approach is used.
 More extensive but versatile approach
for upper & middle regions of facial
skeleton, zygomatic arch & TMJ.
 Advantage- scar is hidden in the
hairline.

48. Rhytidectomy Approach
 Incision made in pre
auricular area and in
the neck hairline
 Skin and
subcutaneous
tissues are incised,
and dissection
carried out above the
level of SMAS