Mandibular morphology change due to mandibular angle osteotomy: a cone beam computed tomography-based three-dimensional cephalometry analysis / 中华医学美学美容杂志

ABSTRACT

Objective:To investigate the effect of mandibular angle osteotomy on the morphological changes of mandible by using cone beam computed tomography (CBCT) scanning data and three-dimensional cephalometry.Methods:According to included and excluded criteria, the complete CBCT data of 20 female patients (aged 20-35 years with an average age of 25.5 years) from January 2016 to June 2018 who underwent curved mandibular angle osteotomy combined with splitting cortiectomy were selected. Seven items reflecting mandibular morphology before and after surgery were measured respectively. All the data were analyzed by the means of SPSS 12.0; linear correlation analysis and paired t test were used to evaluate the change of andibular morphology.Results:The measurement results of the mandible pre- and post-operative 10 days showed as follows Go-Go decreased, both sides of Cd-Go, Go-Ri and MR-MA decreased, both sides of Go-Me became longer, both sides of Ar-Go-Me and MP-FH increased. The paired t-test results showed that there was significant difference before and after operation ( P<0.05), but there was no significant difference between the left and right measurement items ( P>0.05). Compared with that in 10 days after operation, the measurement items also changed 6 months after operation. There was no statistical difference between the above measurement items 6 months after surgery and 10 days after surgery ( P>0.05), and no statistical difference between the left and right sides ( P>0.05). Conclusions:The mandibular three-dimensional model which is reconstructed based on CBCT data, not only displays the three-dimensional anatomical structure that cannot be presented on X-ray film visually and comprehensively by means zoom, rotation and other operations, but also precisely and accurately shows the change of the shape of the mandible from the sagittal, coronal and horizontal plane with arbitrary cutting and rotation. The measurement of mandible is more accurate and reliable, and the surgical plan of mandibular angle osteotomy can be accurately planned preoperatively, and the operative effect can be quantitatively evaluated postoperatively.