[Severe Class III malocclusion: long-term stability. Retrospective analysis of 12 cases]. / Classes III sévères: stabilité à long terme. Etude rétrospective: à propos de 12 cas.

ABSTRACT

PURPOSE: Long-term stability of severe class III is rarely evaluated in the literature. We present our findings with 12 patients who underwent surgery from June 1995 to December 1997 and analyze cephalometric superpositions. MATERIALS AND METHODS: Twelve operated patients were reviewed to analyze long-term results (follow-up 3 years 8 months). The sex ratio was well balanced. Mean age was 23 years. All patients were given pre- and postoperative orthodontic care and underwent bimaxillary surgery with Lefort 1 osteotomy and sagittal osteotomy of the rami. Delaire cephalometry on preoperative and early and late postoperative films was used to analyze outcome. Skeletal instability was defined as displacement greater than 4 mm. Recurrence was defined as secondary loss of the functional and esthetic result. RESULTS: Four patients (33%) developed skeletal instability. All patients achieved long-term stability. DISCUSSION: To detail the cause of skeletal instability, study of the principal factors of instability is presented together with a discussion of data in the literature.