Effects Of Twin-block With Expanding Device Therapy On The Upper Airway In Growing Children With Mandibular Retraction In Skeletal Class Ⅱ Malocclusion

Objective:1.By comparing the differences in gender of the upper airway in growing children with skeletal Class Ⅱ malocclusion,it provides a reference for the clinical orthodontic diagnosis of growing patients of different genders.2.By comparing the upper airway changes in children with skeletal Class Ⅱ malocclusion before and after the treatment with Twin-block combined with maxillary expansion,explore the effects of Twin-block with expanding device on the upper airway of children with skeletal Class Ⅱ malocclusion,and provide a reference for clinical treatment of children with OSAHS that may exist.Methods:A total of 65 children with skeletal Class Ⅱ malocclusion who were treated in the orthodontics department of our hospital from 2017 to 2019 underwent Twin-block combined with expanding device treatment and completed the treatment before 2020.The patient’s lateral cephalograms before and after treatment were imported into Dolphin Imaging software to describe the airway contour,and were imported into The Geometer’s Sketchpad software to calculate the upper airway area and the area of each segment,the height of the upper airway and the height of each segment,and the length of each boundary plane of the airway,the sagittal diameter of the airway,and soft palate-related measurement items.SPSS 22.0 were used for statistical analysis.The upper airway measurement items before treatment were analyzed by independent sample T-test for male and female differences,and the paired T-test was used to explore the effects of Twin-block with expanding treatment on the upper airway of children with skeletal class Ⅱ malocclusion.Results:1.In the influence of gender differences on the upper airway,the velopharyngeal height and the length of the soft palate tip plane in women were significantly larger than those in men,and the velopharyngeal height in women was significantly smaller than that in men(P<0.05);2.After Twin-block with maxillary expanding device treatment,the total area of the upper airway and the area of each airway segment,total airway height,nasopharyngeal height,glossopharyngeal height,laryngopharyngeal height,airway length in PNS plane,soft palate tip plane and epiglottis plane,the sagittal diameter of the nasopharynx,the oropharynx and the laryngopharynx,and the pharyngeal airway space all increased significantly,and the soft palate angle was significantly reduced,which was statistically significant(P< 0.05).Conclusions:1.In growing children with skeletal class Ⅱ malocclusion,the female airway is slightly larger than that of the male,but there is no significant difference between different gender.2.Twin-block with maxillary expanding device treatment can widen the nasopharynx,velopharynx,glossopharynx,and laryngopharynx to a certain extent.Clinically,Twin-block with maxillary expanding therapy can be used to avoid and treat the potential risk of OSAHS in children that may exist.