Cephalometric alterations following facial advancement surgery: 1. Statistical evaluation. A review of aesthetic evaluation of the face and an attempt to assess treatment validity.

Simultaneous maxillary and mandibular advancement surgery, with or without chin advancement, was performed to correct combined mid and lower dento-facial deficiency, the diagnosis of the deformity in this study being based purely on a clinical analysis. The purpose of this investigation was to test the validity of the diagnosis, surgical treatment objective, and subsequent surgical result, by comparing pre- and postoperative cephalometric data with 'Class I dento-skeletal parameters', derived from three different analyses. Lateral cephalometric radiographs were obtained from patients who had undergone 'facial advancement surgery'. The radiographs were subjected to cephalometric analysis in an attempt both to quantify and qualify the skeletal and dental changes that had taken place, following surgical correction of 'horizontal facial deficiency'. A statistical analysis was then used to assess postoperative change to normal, and how the proportion of patients so defined varied by method. All patients had optimal improvements in aesthetics, and in dental occlusion. Dento-skeletal changes remained stable at 12 months post surgery. In spite of these successes, the results of this investigation showed that no greater than 50% of preoperative abnormal measurements per patient were normalised by surgery.