The Three Dimensional Research Of Mandible And Chin Morphology In Skeletal Class ? Adult Patients With Different Verticl Facial Types

OBJECTIVE:Application of CBCT research skeletal Class ? of different vertical facial types and mandible and chin correlation of morphological characteristics.This research provid relevant data to support for orthodontic dignosis and analysis,the choice of the treatment plan and prognosis judgement.METHODS: Plane of FMA(Frankfort mandibular plane angle,orbital ear plane and mandibular plane angle)as the standard,select FMA>36.9 degrees of patients 15 cases were classified as high angle group;25.7 degrees <FMA<36.9 degrees of patients 15 cases were classified as average angle group;FMA<25.7 degrees of patients 15 cases were classified as low angle group,those adult patients were selected between 2011 to 2015 from Shenyang stomatological hospital,department of Skeletal Class ?,according to the Hassel cervical vertebral maturation degree evaluation method to determine the selected patients whether the growth and development of complete.Application Invivo Dental 5 software measured Co-Go,Co-Co',Go-Me,Go-Go',?Go-Me-Go',?Go-N-Go',?Co-Me-Co',?Co-Go-Me and chin height,chin thickness,chin thickness/chin height,minimum thicknessof the the chin,minimum thickness of chin/chin thickness,mentoanterior thickness,mentoposterior thickness,chin curvature,chin angle.Data import Excel Microsoft software to collate,First,used Indepent sample t test and One-Way ANOVA test the normality and homogeneity of the samples in the SPSS 19.0 software,all measurement items are recorded in a standard deviation of mean and standard deviation.If the homogeneity of variance using test SNK-Q to reflect the differences of data between the groups of the mandibular and chin,if uneven variance using rank sum test,inspection standard for P < 0.05 have statistical significance.Application of SPSS 19.0 in Pearson correlation analysis to study the FMA and expression correlation between mandibular and chin morphology characteristics of measurement index,If the R value is positive correlation,if the R value is negative,both of them are negative correlation.(P<0.05).RESULTS: ? Co-Go,Co-Co',Go-Go',?Go-Me-Go',?Go-N-Go',?Co-Me-Co' of average angle group were greater than high angle group,but ?Co-Go-Me is less than high angle group.? Co-Go,Go-Go',Go-Me,?Go-Me-Go',?Go-N-Go'of average angle group were less than low angle group,but?Co-Go-Me is greater than low angle group.? ALL the indicators measured values were less than angle group.? High angle chin thickness,minimum thicknessof the the chin,minimum thickness of chin/chin thickness are less than low angle group.Chin curvature and chin height are greater than low angle group.? After correlation ananlysis found that are positively related with FMA for chin height and chin curvature,that are negatively correlation with FMA for chin thickness/chin height,the minimum thickness of the chin,the minimum thickness of the chin/chin thickness and chin curvature.CONCLUSION: ? The low angle group of skeletal class ? patients with mandbilar branch higher than the high angle group and the lengteh of mandibular shorter than high angle group.The mandibular of low angle group wider than high angle group.?Skeletal Class II patients with mandibular morphology correlated with vertical facial type.?The low angle group of skleltal class ? have wider and prominenter chin morphology than high angle group.?Skeletal Class II patients with chin morphology correlated with vertical facial type.