Refinement of Sagittal Splitting Ramus Osteotomy of Mandible

Kim, Seok Kwun

Abstract

The most important factor in the beauty of the chin is the harmony of the facial skeleton and soft tissue. The surgery of the chin has the special role in plastic surgery of its importance in facial anesthetics in consideration of asymmetry, unbalance and disharmony. The goal of surgical treatment of mandibular prognathism with asymmetry is to achieve maximal aesthetic improvement commensurate with attainment of a stable functional occlusion. Sagittal split ramus osteotomy(SSRO) is one of the surgical techniques used to correct mandibular deformities. In order to prevent many surgical anatomical problems, we must know the anatomical structure related to SSRO. Accurate preoperative evaluation and choice of proper operation method improve the postoperative result. From March 1991 to February 2003, we have performed 71 cases of SSRO successfully. Our operation technique was unique and effective for splitting of mandibular ramus as follows. At first, medial horizontal osteotomy was done just above the mandibular lingula within 4mm by using guarded reciprocating saw. Next, lateral vertical osteotomy at the 1st or 2nd molar teeth was followed by osteotomy using sagittal saw in 5mm depth on the anterior border of the ramus between the previous two osteotomy region. Then sagittal splitting of the ramus was done carefully with curved osteotome. After that, 3-point fixation using passive repositioning screws was done. 2 screws were fixed at superior and inferior area of 5mm posterior to the vertical cut on the lateral cortex, 1 screw was fixed at the more posterosuperior area on the lateral cortex. Anatomic consideration of mandible is very important in this procedure. Then we studied in 71 patients with regarding improvement of facial contour and dental occlusion, cephalometric alteration, change of sensibility, maximal mouth opening, and amount of relapse. We achieved satisfactory results and less complication, our patients were satisfied with good contouring and dental occlusion. Although amelioration of sensory complaint after SSRO needed a longer period than previously expected in general condition of the nerve regeneration, author's modification of SSRO was useful method to reduce the postoperative complication.