4. TMJ develops from the 1st branchial arch mesenchyme
Three phases in the development of the TMJ are :
1) Blastematic stage (weeks 7–8 of development):
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.
2) Cavitation stage (weeks 9–11 of development):
Corresponds to the initial formation of the inferior joint cavity (week 9) and the
start condylar chondrogenesis.
3) Maturation stage (after week 12 of development):
5. Bilateral diarthrosis
Articular surface covered by fibrous
cartilage instead of hyaline cartilage
Only joint in human body with rigid
end point of closure ,due to occlusion
TMJ is last to develop (i.e., in about 7th
week of uterine life)
6. A) Upper Articular Surface
• Articular tubercle
• Anterior part of the mandibular fossa
• Posterior non-articular part formed
by tympanic plate
B) Lower Articular Surface
• Head Of the mandible
8. ARTICULAR
EMINENCE
• Transverse bony bar that forms the anterior root of
zygoma.
• Most heavily travelled by the condyle and disk as they ride
forward and backward in normal jaw function.
ARTICULAR
TUBERCLE
• small, raised, rough, bony knob on the outer end of the
articular eminence.
• Projects below the level of the articular surface
• Serves to attach the lateral, collateral ligament of the joint.
• Slightly hollowed, almost horizontal, articular surface
continuing anteriorly from the height of the articular
eminence.
PREGLENOID
PLANE
9. E: Articular eminence
Enp: entogolenoid process
t: articular tubercle
Gf: Glenoid fossa
lb: lateral border of the mandibular
fossa
pep: preglenoid plane
10. Glenoid Fossa
• separates the joint from middle cranial
fossa
• Lined by : dense avascular fibrocartilage
• Squamotympanic fissure separates it from
tympanic plate, forms posterior wall of
glenoid fossa
11. Parts :
Medial rim:
lateral to : - spine of sphenoid
- foramen spinosum (middle
meningeal artery)
Lateral rim continues:
anteriorly into zygomatic tubercle
(which can be felt under the skin )
posteriorly into postglenoid tubercle
12. ⚫ Chorda tympani nerve appears at the medial end of petro tympanic fissure
close to spine of sphenoid.
⚫ Roof of fossa is thin (separates brain from joint) – avoid perforation of roof
during surgery of roof.
⚫ Important surgical landmark during dissection down to the joint from
a preauricular approach.
⚫ Posteromedially: contents of the middle ear, damaged by injudicious surgery
Clinical Significance :
13. Condyle
⚫ Elliptical shape
⚫ Long axis : 15-330 to frontal plane
900 to body of mandible
⚫ It has a medial and lateral pole
⚫ The medial pole is directed more
posteriorly
18. ⚫ Anterior band (2mm)
Narrow anteroposteriorly
⚫ Posterior band (3mm) –
Thickest and widest
⚫ Intermediate zone : (1mm)
Thinnest
⚫ More posteriorly :
Bilaminar or retrodiscal region
Three zones:
19. ⚫ Anterior:
- Confluent with capsule,
fascia of lateral pterygoid
(Superior head)
⚫ Posterior:
- Retrodiscal tissue
20. ⚫ Shock absorber (less friction & heat production)
⚫ Designed to transmit forces generated through the condyle to the articular
eminence
⚫ Protection for bony components
⚫ Promotes lubrication
⚫ Stabilizes the condyle against the temporal articulation
Function:
21.
22. Capsule-
1) Attached :
Above to rim of glenoid fossa &
articular eminence
Below to periosteum of neck of condyle
2) Attachments of Capsule :
• Anterolaterally : articular tubercle
• Laterally : lateral rim of the mandibular fossa
• Posterolaterally : postglenoid process
• Posteriorly : posterior articular ridge
• Medially : medial margin of the temporal fossa
• Anteriorly : preglenoid plane
24. Lateral retraction of capsule allows access to upper joint space.
Function :
⚫ On the lateral part of the joint, capsule functionally limits the
forward translation of the condyle.
⚫ Medially and laterally - blends with the condylodiscal ligaments
26. ⚫ During Preauricular incision ( expose lateral aspect of TMJ),
protect temporal branch of facial nerve by having the
dissecting plane under superficial layer of deep temporalis
fascia until root of zygomatic arch is reached
⚫ Reflect tissue close to periosteum & desend inferiorly to
expose the entire lateral capsule
⚫ Parotid is usually found between posterior capsule and postglenoid tubercle.
Extends till it reaches lateral wall of pharynx.
⚫ Enlargement of Parotid can impinge on posterior capsule of TMJ & cause pain
during closure of mouth or during chewing movements
27. Lateral/TM Ligament -
• Main stabilizing ligament
• Thickened capsule
• Collagen fibers
Course:
• Down and back
• Attached above to articular eminence
• Below to outer & post side of neck of condyle
• Posterior fibers unite with capsule
28. Function:
⚫ Limits protraction
⚫ Inferior distraction
⚫ Posterior movement of condyle
⚫ Specific length & poor ability to stretch- maintains integrity & limits movement
of TMJ (mainly anterior excursion & prevents posterior dislocation – CHECK
LIGAMENT)
Slippage of condyle:
• medially prevented by Glenoid process
• laterally by TM ligament
29. COLLATERAL/DISCAL LIGAMENT-
⚫ Attach medial & lateral borders of articular
disc to the poles of the condyle.
⚫ True ligament
(collagen i.e. don’t stretch)
Function:
• Restrict movement of disc away from condyle (allow disc to move passively
with condyle as it glides anteriorly & posteriorly)
• Hinge movement
30. 1) Sphenomandibular Ligament :
Arises:
from spine of sphenoid
Inserted into:
Lingula of mandible
Accessory Ligaments :
31. Relations -
Laterally- lateral pterygoid muscle
Posteriorly- auriculotemporal nerve
Anteriorly- maxillary artery
Inferiorly- the inferior alveolar nerve & vessels, a lobule of the
parotid gland
Medially- medial pterygoid with the chorda tympani nerve and the
wall of the pharynx with fat and the pharyngeal veins intervening
32.
33. • The ligament is pierced by the
mylohyoid nerve and vessels
• This ligament is passive during
jaw movements, maintaining
relatively the same degree of
tension during both opening
and closing of the mouth
34. • Internal Maxillary artery
• Auriculotemporal nerve lies
between it & neck of
mandible.
• Chorda tympani branch of
facial nerve crosses the
ligament at the upper end.
Important landmark during surgery:
35. Significance :
• Forms broad impermeable wall medial to
mandibular foramen.
• During IANB , it holds LAconcentrated against the nerve and
prevents fluid from dissipating into adjacent soft tissue.
• Loose areolar tissues present in it, during blunt dissection, help define
the posterior limits of capsule. It can cause abundant venous
hemorrhage.
36. 2) Stylomandibular Ligament :
⚫ Thick deep cervical fascia
⚫ Origin: Styloid process
⚫ Insertion: Angle of mandible
Function:
⚫ Restrict movement of disc away from condyle
⚫ Hinge movement
37.
38. ⚫ Lateral pterygoid muscle attachments are of surgical significance, since it is
not possible to remove the head of the condyle without sectioning the insertion
⚫ Where reattachment does not take place, some joint function is lost and
deviation of the jaw occurs when opening widely.
41. Lateral aspect of capsule:
⚫ Superficial temporal artery
Deep & posterior aspect of retrodiscal capsular part
⚫ Branches of Internal Maxillary artery
( Deep auricular, Posterior auricular, Massetric branches)
⚫ The blood supply to TMJ is only superficial, no blood supply inside the capsule
⚫ TMJ takes its nourishment from Synovial fluid
43. ⚫ Auriculo temporal nerve –
- posterior
- medial
- lateral parts of the joint
⚫ Massetric nerve
⚫ Branch from posterior deep temporal nerve for anterior parts of joint
45. Laterally -
Skin and fascia
Parotid gland
Temporal branches of facial nerve
Medially -
Tympanic plate (seperates from ICA)
Spine of sphenoid
Auriculotemporal and chorda tympani nerve
Middle meningeal artery
Maxillary artery
Superiorly -
Middle cranial fossa
Middle meningeal vessels
Inferiorly –
Maxillary artery and vein
46. Condyle :
◦ More flattened
◦ Fibrous capsule : thicker
◦ Osteoporosis
◦ Thinning or absence of cartilaginous zone
Articular Disc :
◦ Thinner
◦ Hyalinization
47. ⚫ Facial nerve
⚫ Auriculotemporal nerve
⚫ Bleeding from medial aspect of the condylar head
• Lateral pterygoid
• Internal maxillary artery
48.
49. Facial Nerve :
The most common anatomical structure
facing during the approaches to the TMJ
The main trunk of the facial nerve exits
from theskull at the stylomastoid foramen.
Distance from the lowest concavity of the
external auditory canal to the bifurcation
of the main trunk of the facial nerve :
1.5 to 2.8 cm
50. From the bifurcation of the facial
nerve to the post-glenoid tubercle-
2.4 to 3.5 cm
Most variable point- at which the
upper trunk crosses the zygomatic
arch ,ranged from 8 mm to 35 mm
anterior to the most anterior
portion of the bony external
auditory canal (mean, 2.0 cm)
51. The reliable anatomic landmark is suture line between the tympanic and
mastoid portions of the mastoid bone, because the main trunk of the facial
nerve lies 6 to 8 mm inferior and anterior to this tympanomastoid suture.
Approximately 1.3 cm of the facial nerve is visible until it divides into
temporofacial and cervicofacial branches
Approximately 1.3 cm of the facial nerve is visible until it divides into
temporofacial and cervicofacial branches
52. Superficial temporal Artery and Retromandibular Vein
• Surgeons usually face the superficial temporal artery during the preauricular
approaches ( usually ligated )
• This branch along with retromandibular vein runs postero-lateral to the
mandibular condyle within the temporoparietal fascia
• Deep to parotid.
• Posterior to neck of condyle and crosses
Zygomatic process
• Divides –
• Temporal branch • Parietal branch
• Runs in superficial fascia
54. Maxillary artery
Maxillary artery is important in condylectomy procedure. Middle meningeal
artery is a branch of internal maxillary artery that passes medial to the
mandibular condyle and could be damaged during the surgical procedures
on TMJ.
55. Layers of Temporoparietal region
1. Temporoparietal Fascia :
• AKA superficial temporal fascia,the suprazygomatic SMAS
• It is the most superficial fascial layer beneath the subcutaneous fat.
• This fascia is the lateral extension of the galea and is continuous with
• the superficial musculo-aponeurotic system (SMAS)
• It is easy to miss this layer completely when incising the skin because it just
beneath the surface.
• The blood vessels of the scalp, such as the superficial temporal vessels,
• along its superficial aspect close to the subcutaneous fat.
• On the other hand, the motor nerves, such as the temporal branch of
• facial nerve, run on the deep surface of the temporoparietal fascia.
56. 2. The subgaleal fascia :
In the temporoparietal region this fascia is well
developed and can be dissected as a discrete
fascial layer if required, but it is generally used
only as a cleavage plane in the standard
preauricular approach.
3. The temporalis fascia :
Is the fascia of the temporalis muscle.
This thick fascia rises from the superior temporal
Line .The temporalis muscle rises from the deep
surface of the temporal fascia and the whole of
the temporal fossa
57. Arises from posterior part of mandibular division of CN V
Runs beneath lateral pterygoid muscle.
Passes from medial surface of condyle &
emerges on to the face behind the TMJ within
the superior surface of theparotid gland.
Ascends posterior to the superficial temporal
vessels, passes over the posterior root of the
zygoma, and divides into superficial
temporal branches.
Auriculotemporal Nerve :
58. Pre-auricular incision :
The superficial temporal vessels and auriculo-temporal nerve may be retracted anteriorly in the flap
The superficial temporal vessels may be retracted anteriorly with the skin flap (sectioning some posterior and
superior branches) or left in place (sectioning frontal branches)..
preauricular incision is made along the natural crease anterior to the tragus. Dissection should be
continued along the cartilage of external auditory canal in order to prevent damaging the auriculotemporal nerve
and superficial temporal artery.
The temporal branch of the facial nerve is protected within the superficial layer of the temporalis fascia.
Make an oblique incision parallel to the temporal branch of the facial nerve, through the superficial layer of the
temporalis fascia above the zygomatic arch.
Superficial layer of the temporalis fascia would be incised 2 cm above the zygomatic arch in an oblique line.
Al Kayat and Bramley (1979) modification :
This modification is used for a wider exposure. They recommended a question mark shaped skin incision which
avoids main vessels and nerves (See Fig.2) About 2 cm above the malar arch, the temporalis fascia splits into
2 parts, which can be easily identified by fat globules between 2 layers which form an important landmark. In this,
temporal facia and superficial temporal artery are reflected with skin flap. Later helps in better healing of the flap
Under no circumstances should the inferior end of the skin incision be extended below the lobe of the ear as it
increases the risk of damage to main trunk of facial nerve. It is particularly important in children where it may be
quite superficial.
59. Submandibular / Risdon’s approach :
After the facial nerve divides into temporofacial and cervicofacial branches, the marginal mandibular branch
originates and extends anteriorly and inferiorly within the substance of the parotid gland.
To provide the safety zone of marginal mandibular nerve, the incision is made 2 cm below the inferior border of
the mandible.The sharp incision is made through the skin and subcutaneous tissue.
Then, the platysma is sharply incised to expose the superficial layer of deep cervical fascia. The fascia is incised at
the level of the skin incision. The facial artery and vein are retracted or ligated. According to the Hayes-Martin
maneuver, ligation and upward retraction of facial vessels protect the marginal mandibular nerve from injury .
Retromandibular / Hind’s Approach :
The retromandibular approach utilizes the void left between the buccal branches and the marginal mandibular
branch or branches, thus avoiding damage and further morbidity to the patient.
Branches of the facial nerve and retromandibular vein may be encountered in the substance of the parotid gland.
There are chances of a salivary fistula as the approach traverses the gland, which can be prevented by
transfixation of the gland capsule.
Bluntly dissect the parotid gland parallel to the direction of the facial nerve branches and towards the posterior
border of the mandible. The dissection should be anterior to the retromandibular vein.
60. GREY`S ANATOMY (40TH EDITION)
SICHER & DUBRUL`S ORAL ANATOMY (8TH EDITION)
SURGICAL APPROACHES TO FACIAL SKELETON BY EDWARD ELLIS III
ANATOMY OF HEAD & NECK BY B.D CHAURSIA
TEXTOOK OF ORAL & MAXILLOFACIAL SURGERY BY NEELIMA MALIK
MANAGEMENT OF TMJ DISORDERS AND OCCLUSION BY JEFFREY P. OKESON
