| Part Ⅰ:ObjectiveIn this study,by measuring jaw,teeth and anteroposterior occlusion plane related indexes of adult type Ⅱ skeletal malocclusions with different vertical skeletal types,to explore the characteristics of anteroposterior occlusion plane of different vertical skeletal types and the correlation between the anteroposterior occlusion plane characteristics and the position of jaw,the vertical height of dental crown and the proximal and distal incline of teeth when the sigittal is contstant,and the differences between them and normal occlusion were compared and explored.In order to provide some new reference and treatment ideas for the treatment of different vertical skeletal types of skeletal class Ⅱ malocclusions.MethodsThe control group meeting the inclusion and exclusion criteria,namely skeletal Iindividual normal occlusion 29 cases,is selected by the way of volunteer recruitment.Sample collection of patients with skeletal Class Ⅱ malocclusion in the experimental group:A total of 90 patients with skeletal Class Ⅱ malocclusion(average 23±2 years old)are screened.The treated subjects were also divided into three groups according to different vertical facial typeshyperdivergent group,low angle group and average one;The cranial lateral radiographs of the two groups of patients were collected to determine the required markers and measurement items for the experiment.The same researcher conducted the experimental operation,and SPSS 26.0 statistical software package was used to conduct statistical analysis on the results of the final measurement indicators,and the relationship between the anterior and posterior dental plane of the experimental group and the position of the upper and lower teeth and mandible was summarized.Results1.There were significant differences in AOP and POP inclination between the control group and the hyperdivergent group,and between the control group and the low angle group(P<0.01);In the experimental group,the AOP,OP incline of the hyperdivergent group was significantly different from the other two groups(P<0.05):hyperdivergent group>control group>low angle group,that is,the inclinations of AOP,OP in hyperdivergent group were steeper than other 2 groups.2.L1-MPmm in hyperdivergent group was significantly increased compared with control group(P<0.01).L7-MPmm in low angle group was significantly higher than that in control group(P<0.05).In the experimental group,U1-PPmm and L7-MPmm showed statistical significant differences between the low angle group and the hyperdivergent group(P<0.05),but no statistical significance between the average angle group and the hyperdivergent group(P>0.05).The former gradually decreased from the the hyperdivergent group to the low angle group,while the latter gradually increased on the contrary.3.In the experimental group,the inclination of maxillary teeth relative to SN and PP,and Mandibular tooth inclination tended to be distantly inclined with respect to MP,and to be mesometrically inclined with respect to SN.There were significant differences in U1-SN,L5-MP,L6-MP and L6-SN among all groups(P<0.05).The differences ofU6-SN,L1-MP and L7-MP were statistically significant between hyperdivergent group and low angle group,and between hyperdivergent and average angle group(P<0.01).U7-SN,U1-PP,U6-PP,L7-SN were statistically significant between low angle group and hyperdivergent group(P<0.05).The differences of U5-SN,L1-SN and L5-SN were statistically significant between low angle and average angle group,and between low angle and hyperdivergent group(P<0.01).4.Pearson correlation results show that:AOP-SN and POP-SN were significantly negatively correlated with SNB,RP-FH and FH-Npo,which represented sagittal position and retraction degree of mandibular,in the experimental group(P<0.01),AOP-SN and POP-SN were significantly negatively correlated with FHI(%)reflecting facial height and growth type(P<0.01),positively correlated with Y-axis Angle,FMA and MP-SN measuring items representing mandibular retrorotation degree(P<0.01),and positively correlated with ANB reflecting the relative relationship between maxillary position(P<0.05)),were positively correlated with PP-FH and PP-SN(P<0.01).5.Pearson correlation results show that:In the experimental group,U1-PPmm was significantly positively correlated with AOP(P<0.05),U5-PPmm was significantly negatively correlated with AOP(P<0.05),and U6-PPmm and U7-PPmm were significantly negatively correlated with AOP and POP(P<0.01).6.Pearson correlation results showed that in the experimental group,U1-SN,U5-SN,U6-SN,U7-SN,U5-PP,L1-MP,L5-MP,L5-SN,L6-SN,L7-SN were significantly negatively correlated with AOP-SN and POP-SN(P<0.05).U1-PP,L6-MP,L7-MP were negatively correlated with AOP-SN,and U6-PP,U7-PP,L1-SN were negatively correlated with POP-SN(P<0.05).7.The results of multivariate regression analysis showed that the AOP inclination had the greatest effect on mandibular position.U5-PPmm,1-SN have the greatest influence on the inclination of AOP.U7-PPmm,6-SN have the greatest influence on the inclination of POP.Conclusions1.AOP showed significant differences among the three groups of different vertical skeletal surface types of skeletal class Ⅱ malocclusion,showing hyperdivergent type>average angle type>low angle type.The POP inclination of hyperdivergent type also showed significant differences with the other two groups,that is,the OP of hyperdivergent group was steepest than that of the other two groups.2.The higher the inclination of AOP and POP in skeletal type Ⅱ malocclusions,the more significant the trend of clockwise mandibular rotation,retraction and hyperdivergent face type.3.The AOP and POP incline of patients with different vertical skeletal types Ⅱwas related to mandible position,vertical height of teeth and tooth inclination angle,and it is necessary to control the tooth inclination and vertical height strictly in the clinical treatment of class Ⅱ cases of vertical dissonance skeletal.Part Ⅱ:ObjectiveThe most common type of malocclusion in clinic is Class Ⅱ malocclusion,and its clinical manifestations mostly affect the functional appearance of the oral and maxillary system of patients.This part has a preliminary understanding of the characteristics of adolescent orthodontics through 5 adolescent cases of skeletal type class Ⅱ malocclusion.MethodsFive underage patients with Class Ⅱ bone malocclusion admitted to the Stomatology Center of our hospital from December 2020 to December 2022 were selected.Systematic orthodontic treatment was performed on each patient to observe the clinical effect.ResultsIn the first three cases,the mandibular leading with functional myoagonist appliance improved the occlusal relationship and the profile,but after the early treatment,the premolar area often appeared open occlusion requiring secondary orthodontic treatment.Coupled with the coordination of micro-anchorage nails,good profile,occlusal relationship and jaw development can usually be obtained,but the treatment cycle is longer and better compliance is required.In the last two cases,the ideal occlusal effect was obtained by means of dental compensation,but the lateral appearance was limited.ConclusionsCompared with the adult period,the adolescent correction is generally less difficult,and the skeletal adaptability is good.A large range of modifications and reconstruction can be carried out,and the new balance and stability can be achieved after the correction;Moreover,the use of micro-implants realizes the inverse rotation of mandibular plane and occlusal plane,which is beneficial to orthodontic treatment and the improvement of facial shape. |
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