Application of the mandibular mid-sagittal plane in the diagnosis and treatment of facial asymmetry

CHENG Jia-long; HOU Min; SONG Da-li; MA Wen; DAI Zhi; LIN Yang-yang

doi:10.3969/j.issn.1673-7040.2017.05.010

Abstract：Objective To use the mandibular mid-sagittal plane to analyze the symmetry of contours and position of the mandible in facial asymmetry patients and to observe its effect in clinical diagnosis and treatment.Methods This study consisted of 45 patients with facial asymmetry.All patients were classified into 2 groups according to three--dimensional measurement results:for the mandibular contour symmetric group and the mandibular contour asymmetric group.The mandibular mid-sagittal plane was used as a reference plane,and mirror technology was employed to analyze the symmetry of contours and the position of the mandible.From this data,the operation plan was created.The correlation of differences between Me-MSP and the measured points of the mandibular contour were analyzed by the Pearson correlation test,pre-and post-operation.The paired t-test was used to compare the differences of the mandibular contour asymmetric group before and after treatment.Results The differences between the two groups in Go-lat-MSP,Me-MSP,MPP3-MSP,MPP7-MSP,MLP3-OP,MLP7-OP,Go-inf-OP were statistically significant (P＜0.05).The difference between the pre-and postoperative Me-MSP,MPP3-MSP,MPP7-MSP,MLP3-OP,MLP7-OP,Go-inf-OP in the mandibular contour asymmetric group was statistically significant (P＜O.001).There was a positive correlation between Me-MSP and bilateral MPP3-MSP (r=-0.684,P =0.001),but no correlation with other variables.Conclusion This method can quantitatively analyze the asymmetry deformity of the mandibular contour and position and offers good clinical guidance for contour surgery.The patients' satisfaction was high and no medical dispute occurred.