| Objective:Analyze the changes of the upper airway tissues around the upper airway in patients with Angle class Ⅰ and Angle class Ⅱ average angle malocclusion before and after orthodontic extraction and study the effects of dental extraction on the angle of Angle class Ⅰ and Angle class Ⅱ average angle the influence of upper airway in patients with malocclusion was compared with the differences in the changes in the tissues around the upper airway of Angle class Ⅰ and Ⅱ equal-angle malocclusion after tooth extraction.At the same time,it provides a certain reference basis for clinical orthodontic diagnosis and treatment.Methods:According to the inclusion criteria,40 patients were randomly selected from 2018.01 to 2020.12 in the Orthodontics Department of Yijishan Hospital,First Affiliated Hospital of Wannan Medical College.Among them,the Angle class Ⅰaverage angle(MP-FH 21.2°-33.4°,average angle 28.74±2.36°)crowded dentition in 20 cases(13 males,7 females,18-24 years old,average age 22.7±1.6 years old)),Angle class Ⅱ average angle(MP-FH 21.2°-33.4°,average angle 29.37±3.42°)20 cases of crowded dentition(11 males,9 females,18-24 years old,average age 21.9±1.8 years)).The patients in the two experimental groups were treated with orthodontic treatment after the first bicuspid teeth of the upper and lower jaw were extracted.Before and after the correction,the same orthodontist performed the upper airway and cranio-maxillofacial structure on the lateral cranial radiographs to describe and measure a total of 21 indicators.Generally,each indicator is measured three times and the average is taken as the final measurement result.Sort out the relevant data,apply statistical software SPSS.22 for statistical processing,use paired sample t test to compare the measurement items before and after the treatment of Angle class Ⅰ and Angle class Ⅱ malocclusion malocclusion within and between groups Differences,further analysis of the changes in the upper airway structure after the treatment of Class Ⅰ and Class Ⅱ facial tooth extraction.Results:1.Changes of various indexes after the treatment of Angle’s class Ⅰ malocclusion.After extraction and correction,the SNA angle,SNB angle,U1-SN angle,and L1-MP angle of the skull and jaw hard tissues all decreased to a certain extent,only the U1-N1 angle increased,and the changes were statistically significant(P<0.05).In the nasopharyngeal segment and velopharyngeal upper airway,the measured value of the upper airway increased slightly,but only the increase of SPP-SPPW in the velopharyngeal segment was statistically significant(P<0.05).There is a narrowing of the V-LPW in the laryngopharyngeal segment.The increase in the distance from the hyoid bone to the plane of the eyes and ears indicates that the extraction and correction have moved the hyoid bone back and down a certain distance.2.Changes of various indexes after the treatment of Angle class Ⅱ malocclusion.After extraction and correction,the SNA angle and ANB angle,which represent the position of the mandible,decreased,and the difference was statistically significant(P<0.05).The upper and lower incisors were adducted,the U1-SN angle and L1-MP angle increased,and the UI-L1 angle decreased.The difference was statistically significant(P<0.05).In the upper airway measurement items,the nasopharyngeal,velopharyngeal and laryngopharyngeal segments had no significant difference before and after correction.In the hyoid bone measurement items,the distance between H-FH and H-NP increased,and the difference was statistically significant(P<0.05),indicating that the hyoid bone shifted backward and downward.3.Comparison of the difference of various indexes before and after extraction of Angle class Ⅰ and Ⅱ average angle malocclusion.After tooth extraction and correction,there was no significant difference in the measurement items related to the skull and jaw bone,except for the ANB angle difference(P<0.05).There was no significant difference in the difference between the teeth-related measurement items.There was no statistically significant difference in the difference of each measurement item of the upper airway between groups.Conclusion:1.For adult patients with Class Ⅰ and Ⅱ average angle malocclusion,the sagittal diameter of each segment of the upper airway did not change significantly after extraction and correction.Therefore,the orthodontic treatment of the extraction of four first premolars will not adversely affect the upper airway segments of adult patients with Class Ⅰ and Ⅱ malocclusion in a short time.2.For adult patients with Class Ⅰ and Ⅱ malocclusion,orthodontic treatment after the removal of the four first premolars,the hyoid bone position tends to move backward and downward,but the effect is not significant3.There is no significant difference in the effect of the orthodontic method of the reduced four first premolars on the related tissues of the Angle class Ⅰ and Ⅱaverage upper airway malocclusion... |
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