The Investigation Of Molar Long-axle Inclination In Skeletal Class Ⅱ Adult Malocclusion With Various Vertical Skeletal Craniofacial Patterns

ObjectiveIn this study, through the measurement of cephalometric adult skeletal Class II malocclusion and skeletal class I and class I malocclusion patients before bit slice Observation of the first molar mesial distal inclination and among different vertical facial skeletal types difference, Study on compensation characteristics of teeth not coordination molar in the sagittal direction and the vertical direction, and provide some ideas and reference for stable treatment design, clinical orthodontic anchorage preparation and postoperative, To provide reference for clinical molar buccal tube.MethodsAccording to the inclusion criteria, Selection of adult skeletal Class II malocclusion cases60cases as experimental group, Select the tooth angle class I and skeletal class I malocclusion cases60cases as control group, Determination of7represents the first molar angulations were cephalometric analysis, Within each group according to the SN/MP angle and FH/MP angle in patients with different vertical facial skeletal types are divided into3groups, By analysis of variance and difference of each index in the group.Results1.Adult skeletal Class II malocclusion measurement indexes: Adult skeletal Class II malocclusion group, there was no significant difference of U6-FH, U6-PP, U6-L6measurements of upper molars among different vertical facial skeletal types between the3groups (P>0.05).Measurements of L6-SN, L6-PP molar were statistically significant differences in high angle group, average angle group, the low angle group (P<0.05), high angle group than in low angle group, average angle group than in low angle group. L6-MP has a statistically significant difference in high angle group, average angle group, the low angle group (P<0.05), high angle group is greater than the average angle group, high angle group than in low angle group; Measurement of the U6-L6values had significant differences in high angle group, average angle group, the low angle group (P<0.05), low angle group is greater than the average angle group, low angle group than in high angle group, average angle group than in high angle group. 2. Angle class I and skeletal class I malocclusion measurement indexes:Angle class I malocclusion group, measured in the U6-SN, U6-PP molar was statistically significant difference in high angle group, average angle group, the low angle group (P<0.05), high angle group is greater than the average angle group, high angle group than in low angle group. Measurement of L6-MP molar was statistically significant differences in high angle group, average angle group, the low angle group (P<0.05), high angle group is greater than the average angle group, high angle group than in low angle group; L6-SN has a statistically significant difference in high angle group and low angle group (P<0.05), high angle group than in low angle group. No significant differences in U6-FH, L6-PP, U6-L6in different vertical facial skeletal types between the3groups (P>0.05).3. Different vertical facial skeletal types in adult skeletal Class II malocclusion group and angle class I and skeletal class I malocclusion group differences: there were statistically significant differences in high angle L6-SN, L6-PP, L6-MP, U6-L6in adult skeletal Class II malocclusion and skeletal class I and class I malocclusion and the angle of the (P<0.05). L6-SN, L6-PP in high angle group and the average angle group in adult skeletal Class II malocclusion is larger than the class I and skeletal class I malocclusion, L6-MP, U6-L6in high angle group and the average angle group in adult skeletal Class II malocclusion is smaller than the angle class I and skeletal class I malocclusion.Conclusions1.Adult skeletal Class II under the mandibular molar itself have mesially declining trend, And the lower molar tilt increases with the mandibular plane angle. Angle on the long axis and the measuring plane molars showed no statistical significance,this may be associated with maxillary protrusion, the principle needs further research.2.Angle class I and skeletal class I on low and high Angle the maxillary molar have distally declining trend, the mandibular molar itself have mesially declining trend, And the lower molar tilt increases with the mandibular plane angle. 3.Adult skeletal Class Ⅱhigh-angle, both angle relative to the Class I high-Angle, the mandibular molar itself have mesially declining trend.