The temporomandibular joint (TMJ) is the joint connecting the jawbone to the skull. It is a bilateral synovial articulation between the temporal bone of the skull above and the mandible below; it is from these bones that its name is derived.The book include the normal anatomy of the joint, etiological factors causing TMJ Ankylosis, its clinical features, diagnostic tools and various surgical modalities of the treatment. Recent advancements like distraction osteogenesis and correction of TMJ Ankylosis leading to correction of TMJ ankylosis induced obstructive sleep apnea is also explained subsequently.