不同垂直骨面型者的颏部形态

Chin Morphology in Subjects with Different Vertical Skeletal Craniofacial Pattern

目的探讨不同垂直骨面型者的颏部是否存在形态差异,以及不同垂直骨面型与下颌颏部形态的关系。方法选择未经正畸治疗的80例青少年错!患者为研究对象,年龄(12.69±0.70)岁,根据下颌平面角的大小分为3组:高角组21例,低角组16例,平均角组43例。拍摄X线头颅侧位片,并进行X线头影测量,分别评价患者的矢状骨骼型、垂直骨骼型和颏部形态。采用方差分析比较3组的颏部形态,并对颅面垂直向发育与颏部形态之间进行相关分析。结果高角组的颏高度大于平均角组和低角组(P<0.05),且高角组颏部更显细长,低角组颏部更显粗短。高角组颏部唇面较低角组更加平直而突度较小(P<0.01),颏角小于低角组(P<0.05)。下颌平面角与颏高度、颏曲度正相关,而与颏厚度/颏高度、颏角之间存在负相关。结论不同垂直骨面型者之间存在颏部形态差异,既是各结构之间相互补偿和协调的关系,也对正畸矫治设计产生影响。

Objective To evaluate whether there is difference with regard to chin morphology in subjects with different vertical skeletal craniofacial pattern and the relationship among them. Methods The sample was composed of 80 adolescents who denied orthodontic treatment history and presented Class I skeletal pattern, aged （12.69±0.70） years. They were divided into three groups according to mandibular plane angle： High angle group（21 cases, FH/MP≥ 32°）, average angle group（43 cases, 22°〈FH/MP〈32°） and low angle group（16 cases, FH/MP≤22°）. Cepholagrams were taken and cepholametrics was employed. Both vertical and horizontal craniofacial pattern were evaluated. In addition, chin dimensions studied included height, depth, ratio （depth/height）, angle, and so on. They were compared between different groups with One-Way ANOVA. Correlation was analyzed between vertical skeletal craniofacial pattern and chin morphology. Results SNA, SNB and ANB presented no significant difference among three groups. Compared with the low angle group, high angle subjects exhibited increased chin height, depth/height ratio, concavity and decreased chin angle. Therefore the chin looked lathier and less protrusive in high angle group. Positive correlation was found between mandibular plane angle and chin height, concavity, curvature （P〈0.05）, negative correlation between mandibular plane angle and chin minimal depth, depth/height ratio, angle. Conclusion Difference emerged with regard to chin morphology in subjects with different vertical craniofacial skeletal pattern, which deserves to be taken into consideration in orthodontic treatment planning.