In the treatment of dentofacial deformities, analysis of skeletal pattern, with evaluation of plaster dental cast, is essential procedure. This study was based on 20 patients with dentofacial deformity who were admitted to the department of oral and maxillofacial surgery Kngnam sacred heart Hospital during the period of Jan 1988 through Aug 1989. We studied serial cephalometric radiogarphs of patients (pre-op, postop immediately, postop 6 moth). The obtained results indicates the good resistance of rigid fixation against relapse in orthognathic surgery.