Quantitative Evaluation of Cephalometric Radiographs of Patients With Hemifacial Microsomia.

Objective: To clarify the morphological characteristics of hemifacial microsomia (HFM) by quantitative analysis of cephalometric radiographs. Design: Retrospective study of imaging data. Setting: Imaging data were obtained from the records of Sapporo Medical University Hospital. Patients: A total of 183 patients with HFM. Main Outcome Measures: We used linear and angular measurements and analyzed the middle face and lower face. Results: The ratios of the affected side to the unaffected (A/U) side of the lateral distance of the mandibular condyle, the mandibular ramus height, and the length of the body of the mandible in the HFM group were significantly lower than in the control group. The inclination of the body of the mandible was significantly larger in the side with HFM than in the unaffected side, and the extent of the mandibular ramus was significantly lower than in the unaffected side. The A/U ratios of the extent of the angle of the mandible and the inclination of the body of the mandible in the HFM group were larger than in the control group. Moreover, the length and the inclination of the body of the mandible had significant correlations with the distance of the shift of the menton. Conclusions: It is suggested that improving the hypoplasia of the length of the body of the mandible and the extent of the angle of the mandible on the affected side will lead to more effective treatment of jaw deformity in patients with HFM.