A Study On The Changes In The Lateral Profile Of The Nasal Soft Tissue After Orthodontic Treatment For Adult Females With Angle Class Ⅱ Division 1 Malocclusion

Object:By using cephalometric analysis to analyze the nasal profile of adult female patients with Angle Class Ⅱ Division 1 malocclusion before and after orthodontic treatment,comparing the nasal soft tissue profile morphology of this type of adult female patient before and after tooth extraction orthodontics,exploring the impact of orthodontic treatment on the nasal soft tissue profile of Angle Class Ⅱ Division 1 adult females,and understanding the differences in the nasal soft tissue profile of Angle Class Ⅱ Division 1 adult females on different vertical skeletal types,provide some reference for the clinical diagnosis and analysis and orthodontic treatment plan formulation of adult female Angle Class Ⅱ Division 1 malocclusion.Method:Collect photos and radiographic data of adult female patients with Angle Class Ⅱ Division 1 malocclusion before and after orthodontic treatment,screen out patients with skeletal Class I who have undergone maxillary tooth extraction orthodontics and completed orthodontic treatment,and classify and group the pre-orthodontic lateral skull films according to the size of the GoGn-SN value.GoGn-SN<27.3 is the lowangle group,27.3≤GoGn-SN≤37.8 is the average-angle group,GoGn-SN>37.8 is the high-angle group,with 20 cases in each of the low-angle group,average-angle group,and high-angle group.Use Dolphin Imaging software to locate points on the lateral skull films of selected patients before and after orthodontic treatment,use Adobe Photoshop CS6 software to measure nasal morphology-related parameters,use IBM SPSS Statistics 25.0 to perform statistical analysis on all measurement project data,analyze changes in nasal morphology-related parameters before and after orthodontic treatment of patients,and compare the nasal soft tissue profile between different vertical skeletal types in the included samples.Results:1.There are certain differences in nasal morphology among patients with different vertical skeletal types.In this sample study population,high-angle patients had significantly larger nasal bone length and nasion-sella angle than average-angle and low-angle patients.However,there were no statistically significant differences in nasal length,nasal height,columella convexity,columella prominence,nasal depth,maxillary protrusion,nasofrontal angle,nasolabial angle,columella-labial angle or nasofacial angle(P>0.05).There were no obvious differences in the size of the lateral profile of the nasal soft tissue among different vertical skeletal types.2.After orthodontic treatment,there were certain changes in nasal morphology.In this sample study population,some relevant parameters changed vertically and sagittally in the lateral profile of the post-treatment nasal soft tissue.The measurement values for nasal dorsum length,nasal base height,nasal base length,nasal depth,maxillary protrusion and nasion-sella angle as well as columella-labial angle showed statistically significant differences before and after treatment(P<0.05).However,the remaining measurement items showed no statistically significant differences(P>0.05).3.Before and after orthodontic treatment in this sample study population,only maxillary protrusion and nasion-sella angle showed statistically significant differences before and after treatment(P<0.05)for low-angle group patients;only nasal depth,maxillary protrusion,and nasion-sella angle showed statistically significant differences(P<0.05)for average-angle group patients;while only nasal dorsum length,nasal base height,nasal base length,and maxillary protrusion showed statistically significant differences(P<0.05)for high-angle group patients.Conclusion:1.There are certain differences in nasal morphology among different vertical skeletal types.High-angle patients have longer nasal bones and larger nasal dorsum axis angles,while no obvious differences were found in the nasal soft tissue profile of the average-angle and low-angle groups2.After orthodontic treatment,the nasal profile of adult female patients with Angle Class Ⅱ Division 1 malocclusion has changed in the sagittal direction,mainly manifested as the backward movement of the nasal base point and the downward and backward movement of the nasal tip point.However,there are certain differences in nasal changes among different vertical skeletal types.