A Study Of Upper Airway In Adolescents Skeletal Class Ⅲ Malocclusion By CBCT

Objective:To Analyze the difference of upper airway shape in patients with class III malocclusion of different vertical facial types,and explore the influence of cervical vertebral maturation on upper airway morphology in skeletal Class III high angle,it can provide some reference for the establishment of upper airway reference value and craniofacial growth and development for different cervical vertebral maturation.Methods:180 adolescents skeletal ClassⅢmalocclusionpatients were selected from Xiamen Stomatological Hospital from 2015 to 2018.Among them,30 cases were high angle type patients of QCVMⅠ（14 males,16 females）,30 cases were low angle type patients of QCVMⅠ（14 males,16 females）,and 28 cases were average angle type patients of QCVMⅠ（12 males,14females）.According to Quantitative Cervical Vertebral Maturation,the high angle type patients were divided into four stages:30cases were in stageⅠ（14 males,16 Females）,34 cases were in stageⅡ（16 males,18females）,26 cases were in stageⅢ（14 males,12 males）,32 cases were in stageⅣ（16 males,16 females）.CBCT images were imported into the Dolphin software to measure the upper airway reconstruction and morphology,The measurement of upper airway with skeletalⅢwas used to make normality test by SPSS 23.0 statistics analysis software,If the measurements obey normal distribution,all measurements were performed by paired t test,one-way analysis and LSD-T.On the contrary,Wilcoxon rank test would be employed.Results:1.The V _total,H4 and V4 of QCVMⅠmale were smaller than that of female（P<0.05）;V1 of QCVMⅡmalewas larger than female（P<0.05）;S3,V3,H4,V4 of QCVMⅢmale were larger than female,while H2 of male was smaller than female（P<0.05）.AP2 and LAT4 in QCVMⅣmale waslarger than that in female and S1 was smaller than that in female（P<0.05）.In addition to the above differences,no statistical difference was found in the other measurements（P>0.05）.2.FromⅠtoⅡ,V _total,H1,LAT1,AP1,LAT2,LAT4,V4 and H1,AP1,V1 and H2 increased gradually in males（P<0.05）.FromⅡtoⅢ,There was no significant difference in LAT1,H2,LAT2 of males and AP1,LAT2,AP2,V3,AP3 of females（P>0.05）.The other measurements gradually increased.There was no change in the measured values fromⅢtoⅣ（P>0.05）.3.There was no significant difference in the H3 of male in the high angle group（P>0.05）,and the other measurement values were smaller than the low angle group;V _total,S1,S2,LAT2,AP,S3,LAT3,AP3,V4 in female high angle group were smaller than that in low angle group（P<0.05）.S1,LAT1,AP2 of male and H1,AP1,V2 of female were smaller in high angle group than in low angle group and average angle group（P<0.05）.H2 and S4 of female in high angle group were smaller than those in average angle group（P<0.05）.No statistical difference was found in the other measurements（P>0.05）.4.There was a correlation between the upper airway measurement value and the craniofacial structure.There were negatively correlated between SN-GOGN and V_total,S1,AP1,S2,LAT2,AP2,V2,S3,LAT3,AP3,AP4,V4（P<0.05）;ANS-PNS had a positive correlation with other indexes except that it was not linearly related to AP2（P<0.05）;there was no linear correlation between GO-GN and LAT1,V1,AP2,H3,AP4（P>0.05）,and was positively correlated with other indexes（P<0.05）.Conclusion:1.The upper airway measurements increased with the increase of bone age.2.There are gender differences in the morphological characteristics of the upper airway.3.In patients with osteopetrosisⅢ,different vertical craniofacial patterns affect the upper airway space,there is the lowest spaces in patients with high angles.4.There was a certain relationship between the shape and size of upper airway and craniofacial bone.