Permanent Teeth Column Osseous Malocclusion ? Class Before And After Orthodontic Treatments Masked On A Comparative Study Of Airway Sagittal Diameter Changes

Objective:(1)To understand the difference between the sagittal diameter of the upper airway of the permanent dentition and the normal sagittal diameter of the permanent dentition;(2)Changes in the sagittal diameter of the upper airway before and after vertical orthodontic treatment;(3)Nnderstanding of the permanent dentition of the skeletal class III mismatch with the class III intermaxillary traction and the mandibular scuttle area before and after the micro-implant anchorage treatment The change of the sagittal diameter and the correlation with the craniofacial structure of the teeth.Methods: Twenty-nine patients with permanent skeletal class III malocclusion,aged 16 to 38 years(21.0 ± 5.7 years),were included in the exclusion criteria,including 12 males and 17 females.ANB angle-8° ~-0.5 °(-2.9±2.0 °),SN-MP angle 17.0 ° ~ 41.0 °(30.6±6.4 °),of which 7 cases of high-angle,low-angle bone type,There were 15 cases of horn type.Fixedorthodontic technique,23 cases with type III intermaxillary traction,6 cases with micro-implant anchorage technique in mandibular cheek shed area,supplemented with muscle function such as "tongue lift" Training,active correction time 23.7 ± 3.4 months.Statistical analysis was performed on the measurement data by Spss22.0 statistical software.Paired t-test was used before and after intra-group correction.Independent sample t-test was used for comparison between the two groups.One-way ANOVA was used for comparison between the three groups.Pearson correlation analysis was used for correlation analysis.Results:(1)The incidence of upper airway stenosis in permanent skeletal class III malocclusion was 62.1%,and the incidence of stenosis in the nasopharynx and pharyngeal stenosis was 72.2%,and the incidence of stenosis in the upper airway was 22.2%.The incidence of upper airway stenosis was different in different vertical bone types: high angle 100%,average angle 53.3%,low angle 42.9%.However,the stenosis range of the upper airway sagittal stenosis in 86.2% of the permanent dentition of the skeletal class III was less than 30%.(2)There was no significant difference in the upper airway sagittal diameter before and after treatment in the high-angle and average-angle cases of the permanent dentition.The upper airway nasopharyngeal segment was treated after the low-angle case correction.PNS-R broadening(P <0.05).(3)Orthodontic skeletal class III malocclusion combined with class III intermaxillary traction group,SNA angle increased,SNB angle decreased,ANB angle increased,SN-MP angle increased(P <0.05),upper airway PNS-R was widened in the nasopharyngeal segment(P <0.05).After treatment with the MIA group in the mandibular cheek shed,the NSB angle decreased,the ANBangle increased(P <0.05),and the upper airway tongue and throat segment TBTPPW narrowed.(P <0.05);Comparison of changes in X-ray cephalometric measurements before and after treatment in two treatment groups: the change in SNB angle and ANB angle increase in the class III intermaxillary traction group was significantly smaller than that in the mandibular cheek area.(4)Pearson correlation analysis was performed on each of the upper airway sagittal diameter segments and X-ray cephalometric measurements of the cranial and maxillofacial measurements.The Pearson correlation analysis was performed only on the MIA case of the mandibular cheek shed.The change of pharyngeal TB-TPPW is negatively correlated with the change of ANB angle(P<0.05).Conclusion:(1)The incidence of upper airway stenosis in the permanent skeletal class III malocclusion was 62.1%,and the incidence of stenosis in high angle cases was 100%.However,86.2% of the stenosis cases were mild stenosis.In the orthodontic clinic,attention should be paid to the upper airway structure of skeletal class III malocclusion.(2)After the permanent Orthodontic Class III malocclusion and simple orthodontic masking correction,the sagittal and sag of the upper and lower jaws were effectively improved.After the treatment of Class III intermaxillary traction,the SNA angle increased and the SNB angle decreased.The upper airway sagittal diameter nasopharyngeal segment PNS-R has a certain degree of widening,but the mandibular plane angle is increased;after the MIA case treatment of the mandibular cheek shed area,the SNB angle is reduced,the upper airway sagittal diameter tongue and throat segment TB-TPPW has a certain degree of narrowing,and the control of the mandibular plane angle is better.It is suggested that the orthodontic clinic should choose differenttreatment methods according to the sagittal and vertical bone type of the malocclusion,and also pay attention to the relationship between the correction result and the sagittal diameter of the upper airway.