Temporomandibular Joint (TMJ) Lecture

Type of Joint

Upper Articular Surface
- Formed by parts of the temporal bone
- Includes articular tubercle and anterior part of the mandibular fossa
- Posterior non-articular part formed by the tympanic plate
Inferior Articular Surface
- Formed by the head of the mandible
Covering
- Articular surfaces are covered with fibrocartilage

Fibrous Capsule
- Attached above to articular tubercle and circumference of the mandibular fossa
- Loose above the intra-articular disc, tight below
- Lined by synovial membrane
Lateral Temporomandibular Ligament
- Strengthens lateral part of the capsule
- Fibers directed downwards and backwards
- Attached to articular tubercle and postero-lateral aspect of the neck of the mandible
Spheno-Mandibular Ligament
- Accessory ligament, remnant of Meckle's cartilage
- Attached superiorly to the spine of sphenoid and inferiorly to lingula of mandibular foramen
- Related laterally to lateral pterygoid muscle, auriculotemporal nerve, and maxillary arch
- Related medially to chorda tympani nerve and wall of pharynx
Stylo-Mandibular Ligament
- Accessory ligament of the joint
- Thickened part of deep cervical fascia separating parotid and submandibular glands
- Attached to lateral surface of styloid process and angle/posterior border of the ramus of mandible

Oval, predominantly fibrous plate
Divides joint into upper (gliding movements) and lower (rotation and gliding movements) compartments
Concave-convex superior surface and concave inferior surface
Prevents friction between articular surfaces, acts as cushion, and absorbs shock
Stabilizes the condyle by filling space between articular surfaces