Three-dimensional computed tomography analysis of mandibular morphology in patients with facial asymmetry and mandibular retrognathism.

INTRODUCTION: The purpose of this study was to analyze the morphologic features of skeletal units in the mandibles of patients with facial asymmetry and mandibular retrognathism using cone-beam computed tomography. METHODS: The subjects consisted of 50 adults with facial asymmetry and mandibular retrognathism, divided into the symmetry group (n = 25) and the asymmetry group (n = 25) according to the degree of menton deviation. Three-dimensional computed tomography scans were obtained with cone beam computed tomography. Landmarks were designated on the reconstructed 3-dimensional images. Linear and volumetric measurements were made on the mandibles. RESULTS: In the asymmetry group, the lengths of condylar, body, and coronoid units were shorter, and condylar width was narrower on the deviated side than on the nondeviated side (P <0.01). The lengths of angular and chin units were not significantly different between the deviated and nondeviated sides (P >0.05). Hemimandibular, ramal, and body volumes were less on the deviated side than on the nondeviated side (P <0.01). CONCLUSIONS: Condylar, body, and coronoid units contribute to mandibular asymmetry in patients with facial asymmetry and mandibular retrognathism.

Treatment of ankylosed maxillary central incisors by segmental osteotomy with autogenous bone graft.

This case report describes the treatment of a 16-year-old girl with ankylosed maxillary central incisors that were noticeably infraoccluded and labially displaced. We performed a segmental osteotomy with an autogenous bone graft in a single-stage surgery to align and level the ankylosed teeth. The dento-osseous segment was successfully repositioned with satisfactory periodontal results.

Orthopedic and orthodontic treatment of Parry-Romberg syndrome.

Parry-Romberg syndrome (PRS) is a degenerative disease characterized by progressive hemifacial atrophy of soft and hard tissues. A 10-year-old girl who had been treated for linear scleroderma at the dermatologic department since the age of 9 years visited the orthodontic department. The frontal facial photograph showed mild facial asymmetry. On the left side, mild atrophy of soft tissue, mild enophthalmos, cheek depression, and dry skin with dark pigmentation were observed. The radiograph showed hypoplasia of both the maxilla and mandible on the left side. Intraorally, she was in the mixed dentition with the dental crowding. This case report describes the treatment of a patient with PRS for 7 years. To minimize the effect of progressive atrophy on facial growth, a functional appliance was used. The facial photographs and radiographic records were periodically taken to analyze the progression of PRS. Although it is impossible to prevent the progress of facial asymmetry, it appears to be possible to limit the atrophic effect on the mandible by stimulating the mandibular growth. After stabilization of PRS, orthodontic treatment by fixed appliance was performed. In addition, autologous fat graft was performed 3 times at 6-month intervals. After the treatment, the patient had a confident smile, and facial asymmetry was improved.

Three-dimensional computed tomography analysis of mandibular morphology in patients with facial asymmetry and mandibular prognathism.

INTRODUCTION: The purpose of this study was to investigate the dimensional changes in each skeletal unit in the mandibles of patients with facial asymmetry and mandibular prognathism. METHODS: The patients consisted of 50 adults with mandibular prognathism, divided into the symmetry group (n = 20) and the asymmetry group (n = 30) according to the degree of menton deviation. Three-dimensional computed tomography scans were obtained with a spiral computed tomography scanner. Landmarks were designated on the reconstructed 3-dimensional surface models. The lines to represent condylar, coronoid, angular, body, and chin units were used. Ramal and body volumes were measured in the hemi-mandibles. RESULTS: In the asymmetry group, condylar and body unit lengths were significantly longer, and coronoid unit length was significantly shorter on the nondeviated side than on the deviated side (P <0.01). Angular and chin unit lengths were not significantly different between the 2 sides (P >0.05). Ramal volume was significantly greater on the nondeviated side (P <0.01), but body volume was not significantly different between the 2 sides (P >0.05). CONCLUSIONS: Both condylar and body units appeared to contribute to mandibular asymmetry, with a more central role of the condylar unit.