<prompt> According to SAWHNEYS classification of TMJ ankylosis, complete joint architecture is destroyed by osseous union and no sigmoid notch is identifiable, this is:Type 1Type 2Type 3Type 4  <response>: SAWHNEYS GRADING OF ANKYLOSIS TYPE 1: Flattening or deformity of the condyle with little joint space seen on the radiograph. Extensive fibrous adhesions seen during operations. TYPE 2: Bony fusion of the outer edges of the articular surfaces with no fusion in the deeper areas of the joint. TYPE 3: A bridge of bone is seen between ramus of the mandible and zygomatic arch. TYPE 4: Entire joint is replaced by a mass of bone. 