Temporomandibular joint (TMJ) ankylosis is a disorder that leads to a restriction of the mouth opening from partial reduction to complete immobility of the jaw. It can be described as fusion of articular surfaces and is an extremely disabling affliction that causes problems in mastication, digestion, speech, appearance, and hygiene. In growing patients, deformities of the mandible and maxilla may occur together with malocclusion. The treatment of TMJ ankylosis poses a significant challenge because of technical difficulties and high incidence of recurrence. Team approach is required for resolving functional, esthetic, psychological or social problems associated with ankylosis. This book is an attempt to present an overview of this condition and discuss the current concepts in its management.