Temporomandibular Joint

Description

The Temporomandibular Joint

Anatomical structure of the temporomandibular joint (TMJ)

Surface anatomy of temporomandibular joint. Mouth closed (left) and mouth open (right)

Name

• Temporomandibular Joint (TMJ)
• Jaw joint
• Mandibular joint

General

• Primary joint associated with chewing and speaking
• Formed by the articulation of the mandible and temporal bone of the cranium
• Located anteriorly to the tragus of the ear on the lateral aspect of the face

Articular Surfaces

• Three articular surfaces
• Mandibular fossa and articular tubercle (of the temporal bone) and head of mandible
• Articular surfaces are separated by an articular disk
• The disk splits the joint into two separate synovial cavities
• Articular surfaces are covered by fibrocartilage (not hyaline cartilage)

Ligaments

• Lateral ligament
• Sphenomandibular ligament
• Stylomandibular ligament

Movements

• Protrusion and Retraction
  • Anterior/posterior movement of the jaw
  • Lateral Pterygoid is responsible for protrusion
  • Posterior fibers of temporalis perform retraction
  • Chewing/grinding is achieved by alternating protrusion and retraction
• Elevation and Depression
  • Opening/closing of meth occurs at the lower part of the joint
  • Depression occurs primarily with gravity
  • Elevation is strong, caused by temporalis, masseter, medial pterygoid

Vascular Supply

• Branches of external carotid artery
  • Superficial temporal Artery
  • Deep auricular Artery
  • Ascending pharyngeal Artery
  • Maxillary Artery

Innervation

• Branches of Trigeminal Nerve
• Auriculotemporal and masseteric branches

---

Clinical Significance

Pathology

• Temporomandibular Joint Dislocation

Procedures

• TMJ Dislocation Reduction

---

See Also

• HEENT Anatomy Main
• HEENT Main

---