A Cbct Study On The Skeletal Contours Of The Face Of Adult Female With Class Ⅱ Division 1 Malocclusion And Different Vertical Skeletal Patterns

Objective: Facial contour is an intuitive feature of facial aesthetics and is composed of facial bones and soft tissues supported by them.Cone beam computerized tomography is adopted in this research 3D reconstruction technology assessment facial bone contour,aimed at understanding Class II division 1 malocclusion of adult female with facial contour and skeleton structure characteristics explore different vertical skeletal patterns,for clinic diagnosis and treatment for design,provide reference for treatment and prognosis.Methods: A total of 100 adult female patients admitted to the Goup 1 Department of Orthodontics,Affiliated Stomatological Hospital of Zunyi Medical University from January 2017 to December 2021 were selected according to inclusion and exclusion criteria.They were divided into three groups according to vertical skeletal patterns: 30 patients in the high angle group(FH-MP > 32 °);30 patients in the low angle group(FH-MP < 22°);The average angle group(22°≤FH-MP≤32°)included 40 cases.The DICOM format of CBCT was imported into MIMCS 19.0 to reconstruct the THREE-DIMENSIONAL coordinate system and then the indexes reflecting facial bone contour were measured.SPSS 22.0 statistical software was used for data analysis.One-way ANOVA was used for comparison of inter-group means,LSD method was used for pial comparison of multi-group means,and P<0.05 was regarded as the criterion of statistically significant difference.Results: 1.Class II division 1 malocclusion of adult females different vertical skeletal patterns hard tissue index ans-me,n-me,n-ans/n-me,ans-me/n-me,n-me/zy-zy,ans-me/go-go statistically significant difference(P<0.05),n-ans,ft-ft,zy-zy,go-go,ft-ft/zy-zy,zy-zy/go-go had no statistical difference(P>0.05);The ans-me,n-me,ft-ft/zy-zy of the high angle group were higher than those of average angle group and low angle group,n-ans/n-me of the low angle group was higher than that of the high angle group,and ans-me/n-me,ans-me/go-go of the high angle group were higher than those of the low angle group.2.Class II division 1 malocclusion of adult females different vertical skeletal patterns zygomatic protrusion index mp-po and zm-ms had statistical differences(P<0.05),while fmo-n-fmo and zm-ss-zm had no statistical differences(P>0.05).The mp-po of low angle group was higher than that of high angle group and average angle group,and the zm-ms of low angle group was higher than that of high angle group.3.Class II division 1malocclusion of adult females different vertical skeletal patterns zygomatic arch protrusion index tp-ztu and zy-po had statistical differences(P<0.05),ztl-ms had no statistical difference(P>0.05).The tp-ztu of low angle group was higher than that of high angle group.The zy-po of low angle group was higher than that of high angle group and average angle group.4.Class II division 1 malocclusion of adult females different vertical skeletal patterns mandibular index go-po,co-go,id-me,GA had statistical differences(P<0.05),cdl-cdl 、go-go had no statistical difference(P>0.05).Go-pog and co-go of low angle group were higher than those of high angle group and average angle group.Id-me and GA of the high angle group was higher than that of the low angle group and the average angle group.Conclusion: In the diagnosis,treatment design,and prognosis of adult women with Class II division 1 malocclusion,facial bone contouring of different vertical skeletal patterns should be considered.Including the face hard tissue index of ans-me,n-me,n-ans/n-me,ans-me/n-me,n-me/zy-zy,ans-me/go-go,zygomatic index of mp-po,zm-ms,tp-ztu,zy-po,and the mandibular index of go-po,co-go,id-me,GA.