骨性Ⅱ类前牙开牙合不同垂直骨面型磨牙高度与切牙代偿的研究

Molar heights and incisor inclinations in skeletal Class Ⅱ open bite adults with different vertical skeletal patterns

目的:比较骨性Ⅱ类前牙开牙合患者不同垂直骨面型磨牙高度及切牙代偿的差异。方法:选择40例骨性Ⅱ类前牙开牙合及20例成年正常牙合为研究对象,根据SN/MP角和FH/MP角将开牙合患者分为高角开牙合组(23例)和均角开牙合组(17例),比较高角、均角开牙合与正常牙合对照组之间磨牙高度及切牙代偿情况。结果:1、前牙开牙合组磨牙高度均大于正常牙合组(P<0.01)。2、高角开牙合组下颌磨牙高度大于均角组(P<0.05)。3、高角组上切牙唇向倾斜度小于均角开牙合组(P<0.05)。4、均角开牙合组下切牙唇倾度大于高角组(P<0.01)。结论:不同垂直骨面型骨性Ⅱ类前牙开牙合患者磨牙高度代偿过度及上下切牙唇舌向代偿有差异,矫治中应结合不同垂直骨面型磨牙高度和切牙代偿情况,明确去代偿或代偿潜力。

Objective：The purpose of this study was to compare molar heights and incisor inclinations in skeletal Class Ⅱ open bite adults with different vertical skeletal patterns, Provide a certain guiding for clinical diagnosis and treat- ment. Method： 40 adults with skeletal class Ⅱ open bite and 20 adults with adequate overbite were examined and divided in- to three groups according to vertical skeletal patterns： the classⅡ anterior open bite with high mandible angle group （n=23） ; the class Ⅱ anterior open bite with low mandible angle group （n=17） ： the class I normal overbite control group （n=20）. Pre- treatment Lateral cephalometric radiographs were taken. The molars height and the incisor positions were evaluated. Multi- variate analysis of variance tests were used to determine the differences between the groups. Result： Significant differences in molar height were found （.P 〈0.01） between the anterior open-bite group and the control group, Mandibular molar height was greater in the class Ⅱ anterior open bite with high mandible angle group （P 〈0.05）. Maxillary incisor to SN angulation was greater in the anterior open bite with high mandible angle group （P 〈0.05） of the three group. Mandibular incisor to mandibular plane angulation was more buccal inclinations in the anterior open bite with low mandible angle group （P 〈0.01）. Conclusion： molar heights and incisor inclinations in skeletal Class Ⅱ open bite adults are different with vertical skeletal pat- terns.