Transverse mandibular deficiency is rare maxillomandibular malrelationship. Most of this malrelationship is considered to be caused by loss of bone substances. This can be corrected by subapical osteotomy, midsagittal vertical osteotomy, midline horizontal L sliding osteotomy, etc., case by case. In these cases, malrelationship after malunion of mandibular fracture, combination of vertical osteotomy and sliding autogenous cortical bone graft was used and favorable results were obtained. Advantages over previous traditional surgical methods were as follows : 1. This method provided easy access and good visibility. 2. It provided broad bone contact area, thus no other operation to obtain bone graft was needed. 3. There were little circumstances to extract teeth. 4. There were no difficulty in tongue movement after operation.