SEMI-SAGITTAL SPLITOSTEOTOMY OF ANKYLOSINGBONY MASS FOR RELEASE OF LONG STANDINGAND RECURRENT TEMPOROMANDIBULAR JOINT BONY ANKYLOSIS.

Background:-Gap arthroplasty is a one of the techniques used to release TMJ bony ankylosis with reported many advantages and disadvantages. The aim of this study was to present and evaluate newsemi-sagittal split osteotomy of ankylosing bony massto release temporomandibular joint bonyankylosis. It was intended to minimize the disadvantage of gap arthroplasty. Patient and methods:-Twelve patients suffering from TMJ bony ankylosis were included in the present study. New semi-sagittal split osteotomy of ankylosing bony mass was implemented. This cut was extended from the most superior point of ankylosing bone mass laterally and directed downward and medially towards the most inferior point of the most constricted part just above the mandibular foramen.Pterygomasseteric sling release was performed.Six quantitative and qualitative calipers were used to assess the technique. Results:-Postoperative interincisal opening was increased significantly and the lower jaw displaced downward without shortening of the mandibular ramus.Only one case out of twelve (8.3%) represented postoperative anterior open bite. Conclusion:-Semi-sagittal split osteotomy of ankylosing bony mass was recommended to preserve the major vital structures at the base of the skull in long standing and recurrent temporomandibular joint bony ankylosis especially with bulbous bony mass