TMJ

Question 1

Describe the anatomy of the TMJ

Answer 1

Articulation of the mandible with the cranium
Anterior and level to tragus of the ear
Superior (cranial) - under surface of squamous part of temporal bone, 2 articular sites (articular tubercle is anterior and convex, mandibular fossa is posterior and concave)
Inferior (mandibular) - condyle of the mandible has a rounded superior edge and ellipsoid circumference, major axis is postero-medial (movement in oblique plane)

Question 2

Name some of the ligaments in the TMJ and their action

Answer 2

Extracapsular - temperomandibular tightens head in retrustion
Accessory - sphenomandibular prevents dislocation, stylomandibular separates parotid and submandibular glands

Question 3

List some disorders of the TMJ

Answer 3

Bruxism - grinding of teeth
Temperomandibular pain dysfunction disorders
Mal-occlusion syndromes

Question 4

Describe the structure and function of the TMJ

Answer 4

Modified synovial joint lined with fibrocartilage
Vulnerable to subluxation
Least stable with an open jaw
Two separate types of movement - gliding (protrusion/retraction), modified hinge (depression/elevation)