CBCT Comparative Analysis Of Oropharyngeal Airway Morphology In Adults Of Different Gender With Skeletal Class Ⅱ Malocclusions

Objective: Study the characteristics of oropharyngeal airway morphology in adult patients with skeletal Class II malocclusion by using CBCT,to investigate the effect of gender on oropharyngeal airway morphology.And the patients with skeletal class I malocclusion of average angle were used as control to compare and analyze the oropharyngeal airway morphological differences between male and female skeletal Class Ⅱ malocclusion with different vertical skeletal pattern,while taking into account the oropharyngeal airway morphology differences between skeletal Class Ⅱmalocclusion and normal skeletal pattern.Therefore,it can provide a reference for the assessment of oropharyngeal airway status,the formulation of individualized orthodontic treatment plans,the prediction of curative effect,and the prevention of iatrogenic oropharyngeal airway problems before orthodontic treatment design for adult skeletal class II patients of different genders.Methods: From 2019-10 to 2021-10,80 male and female patients with skeletal class II malocclusion and 40 patients with skeletal class I malocclusion were selected from untreated adult patients admitted to the Department of Orthodontics,Affiliated Hospital of Inner Mongolia Medical University.Aged between 25 and 35 years old.All subjects were divided into three groups according to SNB angle and Go Gn-SN angle,named as class II(high angle)group,class II(average angle)group and class I(average angle)group,with 40 cases in each group.According to gender,each group was divided into two groups,male and female,with 20 cases in each group.All subjects were taken CBCT images before treatment,and the obtained imaging data were imported into the three-dimensional image processing software Invivo 5.0 for measurement.The measurement items included sagittal length,transverse width,cross-sectional area of the inferior velopharyngeal and inferior borders of the oropharyngeal airway,the height and volume of the velopharyngeal segment and the glossopharyngeal segment,and the total volume of the oropharyngeal airway in each group of subjects.The above measurement data were statistical analyzed by SPSS18.0 software package.Results:(1)There were obvious gender differences in the oropharyngeal airway morphology of the Class II(high angle)group,the Class II(average angle)group and the Class I(average angle)group.There were significant differences in the cross-sectional area,sagittal length and cross-sectional area of the inferior velopharyngeal border of the oropharyngeal airway between women(P<0.05).The difference in the cross-sectional area of the inferior glossopharyngeal boundary between men and women in the Class I(average angle)group was more significant(P<0.01);The difference in glossopharyngeal volume between males and females in class II(high angle)group and class I(average angle)group was statistically significant(P<0.05),and the difference was more obvious in the class II(high angle)group(P<0.01);there was no significant difference in the measurement data between men and women in the other groups(P>0.05);(2)The oropharyngeal airway measurement data of male groups showed a trend of class I(average angle)group > class II(average angle)group > class II(high angle)group.The sagittal length,cross-sectional area,velopharyngeal volume,glossopharyngeal volume and total oropharyngeal airway volume of the hypopharyngeal boundary were significantly different(P<0.05);(3)The oropharyngeal airway measurement data of the female groups also showed a trend of class I(average angle)group > class II(average angle)group > class II(high angle)group.The sagittal length,cross-sectional area and glossopharyngeal volume of the hypopharyngeal junction were significantly different(P<0.05);the height of the glossopharyngeal segment in the class II(high angle)group was also lower than that in the class II(average angle)in both men and women.The difference was statistically significant(P<0.05),but there was no significant difference between the class II(average angle)group and the class I(average angle)group.Conclusion:(1)There are gender differences in the oropharyngeal airway morphology of 25-35-year-old adults with skeletal class II high angle,average angle and skeletal class I malocclusion of average angle.The oropharyngeal airway is wider in men;(2)When the same angle is average,there are also differences in the oropharyngeal airway morphology between male and female skeletal Class II malocclusion and normal skeletal facies,and the oropharyngeal airway is more narrow in the former;(3)With the change of vertical skeletal pattern,the oropharyngeal airway of male and female patients with skeletal class II malocclusion showed a trend that the higher angle was smaller than the average angle.Compared with the oropharyngeal airways in males,the velopharyngeal and glossopharyngeal morphology are different;while in females,the difference between the two different vertical skeletal patterns is mainly reflected in the glossopharyngeal.