Ankylosing spondylitis (AS) is a chronic autoimmune disease mainly involving the axial skeleton. The pathology of the disease is usually found at the sacroiliac joint, and half of the patients experience cervical spine invasion, but eventually, the whole spine is affected. The involvement of the temporomandibular joint (TMJ) in AS has not been investigated very well. A review of the literature revealed that there are only a few studies of TMJ involvement in AS that combined clinical and radiographic examinations. These studies show widely different results, ranging between 4% and 32%. We experienced Bilateral osseous ankylosis of the jaw treated by total alloplastic joint replacement in AS, and offer a case report.