TMJ Locking:
TMJ locking refers to a limited degree of jaw movement. This restriction of jaw movement may be due to a physical obstruction. TMJ locking results from severe displacement of disc leading to inability of the condyle to gain access to the under surface of the disc during mouth opening.

Mouth opening may gradually improve due to gradual stretching of the disc attachment or reduction of the disc displacement.

Aetiology :
TMJ is an arthrodial joint which is unique in its anatomy and traction. Various factors such as teeth, trauma, deglutation, psychodynamics, speech, and sex of individual influence the normal functioning of the TMJ. Various factors to be considered in the evaluation of craniomandibulor disorders are genetic, developmental, physiological, trumatic, pathological, environmental, mental and behavioural factors.