Correlation Between The Angle Of The Maxillary Incisors And The Angle Of The Soft And Hard Tissues Of The Young Class Ⅱ~2

Objective:To study the correlation between the inclination angle of the maxillary incisors and the soft and hard tissue characteristics of the patients with Class II~2malocclusion and the correlation between the change of the inclination angle of the maxillary incisors and the changes of soft and hard tissues.According to the angle of the maxillary incisors,the severity of the malocclusion and the changes that can be caused by the correction are evaluated,which provides a reference for the clinical diagnosis and treatment of young patients with Class II~2 malocclusion.Methods:From the orthodontic cases in which the treatment of the Department of Stomatology of the Fifth Affiliated(Zhuhai)Hospital of Zunyi Medical University was completed during 2010-2018,80 patients with malocclusion were selected according to the inclusion criteria,including 36 male patients and 44 females.The age ranged from 12 to 16years,the average age was 13.77 years,and the correction time was about 21 to 33 months.U1-NA°(upper jaw incision angle)≤7.47°(mean)was severe,45 cases,U1-NA°>7.47°is a mild group,a total of 35 cases.The computerized head shadow measurement software AngelCeph8.0 was used to measure the X-ray of the lateral position of the skull before and after treatment.The data of 19 hard tissue indexes and 6 soft tissue index data were output.The statistical data of the measured data were statistically processed by SPSS22.0statistical software.To analyze the characteristics of soft and hard tissues before and after treatment in adolescent patients with Class II~2 malocclusion and the correlation with the angle of the upper incisors.Results:(1)The comparison of soft and hard tissue changes after treatment of young patients with Class II~2 malocclusion showed:the U1-NA angle,the L1-NB angle,the SNB angle,the MP-FH angle,the APDI value,the U1-NA distance,the L1-NB distance,the ANS-ME distance,the N-ME distance,the Go-Pg distance,the Go-Co distance,the Z angle,and the labial angle were increased compared with those before treatment(P<0.05).the ANB angle,the U1-L1 angle,the ODI value,the SE distance,the Si to(Li-Pog’),the nasolabial angle,the Upper Lip E-plane,the Lower Lip E-plane were all reduced(P<0.05);the SNA angle,the Pog to NB,the Ptm-A,and the Y-axis angle are different from those before correction,but the difference is not obvious(P>0.05).(2)Correlation between soft and hard tissue and the U1-NA angle before treatment showed:the L1-NB angle,the MP-FH angle,the APDI value,the U1-NA distance,the L1-NB distance,the ANS-ME distance,the N-ME distance,the Go-Pg distance,the Go-Co distance,the lip angle and the U1-NA angle were positively correlated(r>0,P<0.05);the U1-L1 angle,the ODI value,the SE distance,the Upper Lip E-plane distance and the U1-NA angle was negatively correlated(r<0,P<0.05).(3)Correlation between the amount of change of soft and hard tissue and the change of the U1-NA angle after treatment showed:the change of L1-NB angle,the change of APDI value,the change of U1-NA distance,the change of L1-NB distance,the change of ANS-ME distance,the change of N-ME distance,the change of Go-Co distance,the change of Lower Lip E-plane and the U1-NA angle change were positively correlated(r>0,P<0.05).(4)Comparison of Young’s Class II~2 malocclusion with severe tongue-dipping group and mild group showed:the L1-NB angle,the MP-FH angle,the APDI value,the L1-NB distance,the Go-Pg distance,the Go-Co distance,and the labial angle were smaller than mild group(P<0.05);the U1-L1 angle,the SE distance,the Lower Lip E-plane of severe lingual group of maxillary incisors were larger than mild group(P<0.05).Conclusions:(1)Adolescents with Class II~2 malocclusion have a greater improvement in soft and hard tissue deformities after orthodontic treatment.(2)The anterior position angle,the mandible development,the face height,and the labial angle of the patients are positively correlated with the inclination of the upper incisors.The relative position of the condyles,the anterior and posterior and the vertical mandibular disorders,the lower lip position and the upper incis on the tongue inclination are negatively correlated.(3)The degree of anterior teeth position,the anterior and posterior jaw dislocation,the mandibular vertical development,the facial height and the lower lip position are positively correlated with the change of upper anterior teeth.(4)In the severe group,the angle of the lower anterior teeth,the relative position of the condyle,the relationship between the anterior and posterior and the vertical mandible,the development of the mandible,and the position and shape of the lower lip are more severe than those in the mild group.