Positional Changes of the Mandible and the Upper and Lower Anterior Teeth After Oblique Sliding Osteotomy of the Mandibular Rami: A Roentgen-cephalometric Study of 55 Patients

Abstract

Oblique sliding osteotomy of the mandibular rami was performed on 55 patients with mandibular prognathism. They were followed-up for positional changes of the mandible and the upper and lower anterior teeth at predetermined intervals for up to 2 1/2 years. Two kinds of positional changes occurred, viz. rotation with shortening of the rami mainly during the intermaxillary fixation period, and an anterior movement, most pronounced after the end of the fixation period and up to half a year after operation. The movements were moderate. The anterior height of the face remained unchanged, while the posterior height decreased in connection with the operation and immobilisation. The positional changes were analysed for any correlation with the preoperative morphology of the skull. During the immobilisation period the anterior teeth of both upper and lower jaws underwent a retroclination, and those of the lower jaw also extrusion. Both types of tooth movement regressed afterwards.