Objective:To present our experience of the surgical treatment of maxillofacial fibrous dysplasia(FD) using surgical navigation technology.Methods:14 patients with maxillofacial FD were included.Preoperative CT scanning data were obtained and a virtual plan based on the patient's mirrored anatomy was realized.Intraoperatively,a digital reference frame was fixed rigidly to patient's forehead or mandible depending on the location of the lesion.During operation each patient and the virtual image were matched through individual registration technique.A pointing device was constantly used to determine whether the extent of resection was consistent with the preoperative design.The surgical outcome was assessed through fusion of the preoperative planning and postoperative CT reconstruction image.Results:The application of surgical navigation system enhanced the safety and the accuracy of the surgery for the resection of the focal lesion and for the recontour of the profile.There was no complications during 1-3 years follow up.Conclusion:Surgical navigation based on a virtual plan proves to be safe and accurate,and is of great value in managing maxillofacial fibrous dysplasia.

Objective : To evaluate the morphology of the upper airway of children with obstructive sleep apnea-hypopnea syndrome (OSAHS) using cone-beam computed tomography (CBCT) combined with polysomnography (PSG) and provide references for clinical practice. Methods: CBCT data of 45 OSAHS children and 45 normal children and PSG data of the OSAHS group were retrospectively collected. Three-dimensional reconstructions were performed using NNT 9.0 software. The total upper airway volume, nasopharyngeal volume, palatopharyngeal volume, glossopharyngeal volume, laryngopharyngeal volume, minimum cross-sectional area, anterior-posterior diameter of the minimum cross-section, and lateral diameter of the minimum cross-section were measured and recorded. According to PSG monitoring results, patients with an obstructive apnea hypopnea index (OAHI) and lowest oxygen saturation (LSaO2) were assessed. Body mass index (BMI) was recorded. The correlation between airway volume parameters, BMI and PSG test results was analyzed. Results: The total upper airway volume, nasopharyngeal volume, palatopharyngeal volume, glossopharyngeal volume, laryngopharyngeal volume, minimum cross-sectional area, anterior-posterior diameter of the minimum cross-section, and lateral diameter of the minimum cross-section of the OSAHS group were significantly reduced compared with those of the control group (P<0.05). In the OSAHS group, the total upper airway volume, the minimum cross-sectional area and the lateral diameter of the minimum cross-section showed moderate negative correlations with the obstructive apnea hypopnea index (OAHI) (P<0.05). Moreover, the total upper airway volume, minimum cross-sectional area, anterior-posterior diameter of the minimum cross-section and lateral diameter of the minimum cross-section showed no correlation with the minimum blood oxygen saturation (P>0.05). No significant correlation was noted between BMI and PSG in the OSAHS group (P>0.05). Conclusion The morphology of the upper airway of children with OSAHS was significantly smaller than that of normal children. CBCT three-dimensional technology for analyzing the upper airway has a certain value in evaluating the morphology and degree of obstruction of the upper airway in children with OSAHS.