How do I manage restricted mouth opening secondary to problems with the temporomandibular joint?

Restricted mouth opening is a common problem that presents to secondary care, and management depends on the primary cause. The most common differential diagnoses related to the temporomandibular joint (TMJ) include muscle spasm secondary to pain, anchored disc phenomenon, irreducible anterior disc displacement, rheumatoid diseases, and ankylosis. In this paper each is considered in turn.