Up to date, various surgical techniques and innovations have been applied to manage the prominent
mandibular angle. One of the most popular method is mandibular angle ostectomy. However, gross asymmetry of the mandibular angles and condylar fracture were frequently found because three dimensional analysis of mandible was overlooked. Most of Asian women desire a small width of the lower face in the frontal plane, so require more than mandibular angle ostectomy; it necessitates contour reduction of bilateral lateral cortex.
  A total of 10 patients underwent surgery to reduce lower facial width. Five of these patients(group I) underwent lateral cortex ostectomy of the mandible and conventional angle ostectomy, and the remaining 5(group II) underwent only lateral cortex ostectomy. In all our procedures we used an intraora approach and performed contour reduction of the lateral cortex in the boundary from 10 mm below the sigmoid notch to 10 mm lateral to the mental foramen. The amount of bone to be resected was determined by examining the bigonial distance: the longer, the larger. To demonstrate the result, photogrametric and cephalometric data were used. The preoperative measurements were compared with those of postoperative.
  As a result, the bigonial distance was sufficiently reduced by a mean valye of 13 mm in group, I, I1 mm in group II. The gonial angle was increased by a mean value of 11 degrees in group I, 2 degrees in group II. There was no significant difference in reduced bigonial distance in groups I and II, but abnormal increased gonial angle was found in group I. Furthermore the lateral cortex ostectomy allows a smooth-out contour of the inferior border of the angle of the mandible without changing the angle itself. 
  It is found that the lateral cotex ostectomy is an effective technique in reducing the width of the lower face, producing a natural relief of the mandibular angle without mandibular angle ostectomy.