[Three-dimensional analysis of pharyngeal airway in skeletal Class III patients after sagittal split ramus osteotomy].

ABSTRACT

OBJECTIVE: To analyze the three-dimensional changes of pharyngeal airway in patients with skeletal Class III malocclusion after the combined orthodontic and orthognathic treatment. METHODS: Twenty patients (9 males, 11 females) and 40 subjects with normal occlusion were involved in the study. Cone-beam computed tomography (CBCT) were performed on patients one week and six months after treatment. Raw data were reconstructed into three-dimensional model and sagittal and transversal measurements, cross sectional areas, partial and total volumes were computed. RESULTS: After treatment, the sagittal diameters of each section were significantly reduced by (2.7 ± 3.5), (3.0 ± 3.8), (2.7 ± 3.3) mm, respectively (P < 0.05). The transversal diameter of laryngopharyngeal airway constricted significantly by (4.8 ± 4.1) mm (P < 0.05). Cross sectional areas and volumes of each part in patients after surgery were significantly narrower compared with those of the controls. CONCLUSIONS: After combined therapy the pharyngeal airway space decreased.