Open bite deformity in amelogenesis imperfecta. Part 2: Le Fort I osteotomies and treatment results.

Functional conditions, skeletal and dento-alveolar stability and condylar changes in 15 patients with mandibular hypoplasia, anterior open bite (AOB) and amelogenesis imperfecta (AI), who had undergone a Le Fort I osteotomy, were analysed after a mean follow-up of 5 years. Two patients underwent a one-piece Le Fort I intrusion osteotomy and 13 patients a multi-segment Le Fort I osteotomy. In three of these patients, an additional bilateral sagittal split osteotomy was performed. Thirteen patients underwent a genioplasty. Surgery was followed by prosthetic rehabilitation in 10 patients. Skeletal and dento-alveolar stability were analysed on lateral cephalometric radiographs and condylar changes on orthopantomographic radiographs. Transverse stability of the dental arches was analysed on dental casts. The treatment results in this group were compared with patients with similar skeletal features but without amelogenesis imperfecta. The harmony of the long faces was restored and a reasonable vertical stability of the maxilla was achieved, however, a slight open bite and tongue interposition was still present. The transverse stability of dental arches (60%) was disappointing. Rigid internal fixation produced better transverse stability. Progressive condylar resorption was seen in two patients (13%). Less occlusal stability could be achieved in patients with AI, but resulted neither in less skeletal stability nor in more susceptibility to morphological condylar changes.