Generally speaking, intratemporomandibular joint ankylosis must be treated surgically. The surgical options are condylectomy and temporomandibular arthroplasty. Condylectomy is used in cases of fibrous ankylosis. Temporomandibular arthroplasty is indicated in cases of bony ankylosis. Extra-articular ankylosis generally requires surgical treatment as well. The basic method is to cut and excise the scar of the contracture of the jaw; chisel away the intermaxillary adhesions to restore the degree of opening and destroy the wound with skin pieces or flaps. If the deformity of lip and cheek tissue is also present, it will be repaired at the same time. I. Principles of temporomandibular arthroplasty surgery 1. The cut-off site should be formed as high as possible in the ascending branch of the mandible. The closer the site is to the original joint activity, the better the functional recovery after surgery. At present, there are two commonly used osteotomy sites: first, the neck of the condyle is cut open to form a pseudo-joint, this surgery is suitable for those with small bone adhesions and limited to the condyle; second, the site below the sigmoid notch and above the mandibular foramen is cut open, this surgery is suitable for those with large bone adhesions and involved in the sigmoid notch, the osteotomy site is too low, and after the osteotomy, the eunuchs use the rib bone with cartilage or skeletal bone free graft for joint reconstruction. 2.The treatment of bone section generally advocates appropriate trimming of the ascending bone section after osteotomy, so that it forms a smaller volume of curved bone protrusion, forming a point of contact with the surface. This is not only beneficial to the movement of the jaw, but also can reduce the chance of bony healing. 3.Keep the gap of the cut-off It is generally believed that the gap of the cut-off should be kept between 0.5~1cm, and various tissues or substitutes can be inserted in the gap. Such insertion can not only separate the bone section to prevent recurrence, but also maintain the bone gap to avoid open tooth closure, which is conducive to the reconstruction of mandibular joint function. 4, the treatment of bilateral intra-articular ankylosis Bilateral intra-articular ankylosis is best operated once, if it must be divided into two operations, the interval should not exceed 2 weeks, so as to avoid scar contracture at the first operation. The age of surgery is still controversial, but it is generally believed that the best age for surgery is when the child can cooperate with postoperative mouth opening training. The treatment of intra-articular ankylosis with small collar deformity In recent years, many scholars believe that the correction of small jaw deformity while performing arthroplasty is not only beneficial to expand the pharyngeal cavity and improve respiration, but also to correct the facial deformity of receding lower jaw to a certain extent, as well as to improve the cardiopulmonary dysfunction and the general dysplasia of children caused by long-term chronic hypoxia. However, due to the complexity of the surgery, the indications should be strictly controlled and the surgery can be performed in stages if necessary.