Two-dimensional and volumetric airway changes after bimaxillary surgery for class III malocclusion

OBJECTIVES: Any change in maxilla and mandible position can alter the upper airway, and any decrease in the upper airway can cause sleep disorders. Thus, it is necessary to assess airway changes after repositioning of the maxilla and mandible during orthognathic surgery. The purpose of this study was to evaluate linear and volumetric changes in the upper airway after bimaxillary surgery to correct class III malocclusion via cone-beam computed tomography (CBCT) and to identify correlations between linear and volumetric changes. MATERIALS AND METHODS: This was a prospective cohort study. CBCTs from 10 class III patients were evaluated before surgery and three months after. The Wilcoxon one-sample test was used to evaluate the differences in measurements before and after surgery. Spearman's rank correlation coefficient was used to test the correlation between linear and volumetric changes. RESULTS: The results show that the nasopharyngeal space increased significantly, and that this increase correlated with degree of maxillary advancement. No significant changes were found in volumes before and after surgery. A correlation was found between linear and volumetric oropharyngeal changes. CONCLUSION: Bimaxillary surgical correction of class III malocclusion did not cause statistically significant changes in the posterior airway space.

[Evaluation of maximum mouth opening after bilateral sagittal split osteotomy in patients with mandibular prognathism]

Mandibular prognathism is one of the most common skeletal disorders in Iranian population and so mandibular setback surgery is one of the most common surgeries in Oral and Mxilllofacial area. Ramus sagittal osteotomy is one of the surgeries which is done for the purpose of mandibular setback or advancement. The purpose of this study was to evaluate the progress of maximum mouth opening [MMO] after bilateral sagittal split osteotomy [BSSO] surgery in patients with mandibular prognathism. In this study, 36 patient's undergone BSSO surgery with Hunsck technique in order to correct manibular prognathism were taken into consideration. In all patients, fixation was done with three titanium screw in each side. Maximum mouth opening was measured before surgery and within 1, 3, 6 months after surgery. Repeated measurement was performed for data analysis [alpha = 0.05]. In the patients 81.32% of maximum mouth opening was gained after one mouth, 92.1/5 after three months and nearly total recovery [98.94%] after 6 months of surgery. The results confirm the concept that limitation in MMO is not a long lasting complication in bilateral sagittal split osteotomy surgery in patients with mandibular prognathism and it would approximatey be as same as before surgery after six months