Three-dimentional Analysis Of Mandibular Morphology And Condylar Position In Skeletal Class ? Patients With Mandibular Asymmetry

Objective: Three-dimensional CT measurements of the mandible of patients with skeletal class ? malocclusion and mandibular asymmetry using Mimics software were performed to investigate the mandibular morphology and condylar position.Methods: Craniofacial CT scans were performed in 50 patients with skeletal class ? malocclusion(aged 18-34).And DICOM data were collected.Then three-dimensional reconstruction of the bone tissue was performed with Mimics15.0.Three-dimensional coordinate system was established and the upper and lower jaws were separated.Then reveal the complete condyle morphology,identify markers and related reference plane to measure the parameters.According to the mandible with or without asymmetry,22 cases were included in the control group and 28 cases were included in the experimental group.SPSS 20.0 statistical software was used to measure the results of chi-square test,paired t test,independent sample t test and Pearson correlation analysis,and test results were analyzed.Results: 1.Experimental group bilateral condylar height,coracoid height,height of mandibular ascending,mandibular body length,condylar diameter,condylar external bevel length,mandibular angle,condylar angle,Go-CP,Go-FH,condylar level plane-CP,condylar level plane-FH,condylar sagittal plane-FH,Sn-CP,Sn-FH and Sn-MSP were significantly different between the two groups(P<0.05).There was no significant difference between the left and right sides of the control group(P>0.05).In the experimental group and control group,the condylar height,mandibular ascending height,mandibular angle,Go-CP,Go-FH,Go-MSP,condylar coronal plane-FH,Sn-CP,Sn-FH and Sn-MSP difference was statistically significant(P<0.05).The difference between the experimental group and the contralateral condylar side of the mandibular condyle height difference,coracoid height difference,mandibular ascending height difference,poor Go-FH,poor Go-MSP,condyle coronal-CP difference,condylar coronal plane-MSP difference,Sn-FH difference,Sn-MSP difference and the degree ofdeviation of the chin point there is a certain correlation.Conclusion: 1.There is asymmetry in mandibular morphology of adult skeletal Class ? patients with mandibular asymmetry.The length of mandibular condyle,the length of mandibular ascending,the length of mandibular body and the angle of mandibular angle were smaller than those on the opposite side of skew,and the height of coracoid was greater than that of skewed contralateral side.Skew side of the mandibular angle backward,upper and lower rotation,skewed contralateral mandibular angle forward,down,within the rotation.2.There is asymmetry in condyle shape of adult skeletal Class ? patients with mandibular asymmetry.The shape of the condyles on the deviated side is relatively small,and the shape of the condyles on the non-skewed side is relatively larger.The difference mainly manifests in the condylar height and the outer bevel.3.There is asymmetry in the condylar position of adult skeletal Class ? patients with mandibular asymmetry.Lateral condyle rotate to back and internal.Sigmoid notch rotate to backward,up and down.Contralateral condyle rotate to forward and outward.Sigmoid notch rotate to forward,down and internal.Left and right joint space have no significant difference.4.There is a certain correlation between mandibular shape and condylar position with level of mandibular deviation in adult skeletal Class ? patients with mandibular asymmetry.