Abstract
A sample of 267 patients with maxillary hyperplasia, a Class I or Class II occlusion and anterior open bite, collected from three different institutions, was analysed regarding stability after Le Fort I intrusion osteotomies or bimaxillary osteotomies. Skeletal and dento-alveolar stability of the maxilla, postional changes of the mandible and of incisors were evaluated on cephalometric radiographs. The stability of maxillary arch dimensions after correction of the open bite is measured on dental casts. Patients with anterior open bite, treated with a Le Fort I osteotomy in one-piece or in multi-segments, with or without bilateral sagittal split osteotomy exhibited good skeletal stability of the maxilla. Rigid internal fixation showed better maxillary and mandibular stability than intraosseous wire fixation. Considerable relapse of transverse dimensions, however, was measured after orthodontic and surgical expansion. The mean overbite at the 69 months follow-up was 1.24 mm and lacking of overlap between opposing incisors was present in 19%.
