Effect Of Mandibular Advancement With Invisible Braces On The Upper Airway Morphology And Structure In Adolescents With Class II Malocclusio

Objective:CBCT was used to measure and analyze the three-dimensional changes of upper airway morphology and structure in adolescent class II malocclusion patients before and after mandibular anterior guidance treatment with clear aligner,and to explore the effect of functional appliance with clear aligner treatment on the changes of upper airway structure in adolescent class II malocclusion patients,so as to provide theoretical support for clear aligner to improve the ventilation ability of upper airway in skeletal Class II patients with mandibular retraction,to provide clinical practice guidance for the treatment of skeletal Class II malocclusion at the peak of growth with clear aligner.Methods:Seventeen patients with skeletal Class II malocclusion at the peak of growth treated with clear aligner with mandibular advancement function in the Department of Orthodontics,affiliated stomatology hospital of Hunan University of Chinese Medicine from2018 to 2021 were selected.The DICOM files of CBCT of patients before and after treatment were imported into Dlophin Imaging 11.9for analysis and measurement,spss26.0 statistical software,the data before and after treatment were analyzed by paired t-test.Results:After mandibular advancement with clear aligner.The total volume of the upper airway increased by 6074.88±4669.68mm ~3,and the difference was statistically significant(P<0.05).The volume of the upper airway of nasopharynx increased by 1157.18±1106.57mm ~3,and the difference was statistically significant(P<0.05).The volume oftheupperairwayofvelopharynxincreasedby2642.88±2275.06mm ~3,and the difference was statistically significant(P<0.05).The volume of the upper airway of glossopharynx increased by 2455.29±2030.17mm ~3,and the difference was statistically significant(P<0.05).The minimum cross-sectional area of the upper airway increased by 83.29±77.79mm ~2,and the difference was statistically significant(P<0.05).The cross-sectional areas at the posterior nasal spine plane of the upper airway increased by86.09±121.12mm ~2,and the difference was statistically significant(P<0.05).The cross-sectional areas at soft palate plane of the upper airway increased by 61.36±43.21mm ~2,and the difference was statistically significant(P<0.05).The cross-sectional areas at epiglottic apex plane of the upper airway increased by76.16±114.71mm ~2,and the difference was statistically significant(P<0.05).The cross-sectional diameters at the posterior nasal spine plane of the upper airway increased by 2.81±4.84mm,and the difference was statistically significant(P<0.05).The cross-sectional diameters at the soft palate plane of the upper airway increased by5.74±4.76mm,and the difference was statistically significant(P<0.05).The cross-sectional diameters at the epiglottic apex plane of the upper airway increased by 2.01±3.43mm,and the difference was statistically significant(P<0.05).The sagittal diameter at the posterior nasal spine plane of the upper airway increased by2.57±3.39mm,and the difference was statistically significant(P<0.05).The sagittal diameter at the soft palate plane of the upper airway increased by 1.04±2.55mm,and the difference was not statistically significant(P<0.05).The sagittal diameter at the apical plane of epiglottis of the upper airway increased by 1.42±3.87mm,and the difference was not statistically significant(P<0.05).Conclusion:Mandibular advancement therapy with clear aligner can increase the upper airway volume of adolescent class II malocclusion and improve the upper airway morphology of patients,which may improve the respiratory function and increase the upper airway ventilation of adolescents.