The purpose of this retrospective study was to evaluate relapse, comparing large and small maxillary advancements with four-plate rigid fixation and without bone grafting. All patients had skeletal class III malocclusion, and underwent bimaxillary surgery. Standardized cephalometric analysis by one examiner was performed on serial radiographs of 14 patients immediately before surgery, and within 1 week and at least 6 months postoperatively (mean 10 months). The group was divided into two subsets to determine whether the magnitude of relapse. In group 1 (< or = 5 mm, n = 8), the average advancement was 4.0 +/- 0.9 mm, with a mean relapse of 0.1 +/- 0.5 mm. In group 2 (6-8 mm, n = 4), the average advancement was 6.8 +/- 0.9 mm, with a mean relapse of 0.7 +/- 0.4 mm. There was no statistical difference in the measured relapse among the groups. Maxillary advancement with a 1-piece Le Fort I osteotomy is a relatively stable procedure.