Germane N, Bentley B E, Isaacson R J
School of Dentistry, Medical College of Virginia/Virginia Commonwealth University, Richmond.
Am J Orthod Dentofacial Orthop. 1989 Oct;96(4):312-9. doi: 10.1016/0889-5406(89)90350-8.
The facial surface contours of 600 maxillary and mandibular teeth, including 50 of each type of tooth from central incisors to first molars, were measured. Facial contours present at the same location, facial contours from occlusal/incisal to gingival surfaces and the angle formed by the coronal and radicular long axes varied among teeth of the same type. The magnitude of the variation found was so great as to suggest that differences between patients or differences in height of bracket placement are greater than the differences between the standard torque prescriptions now used in orthodontics. No single point, including the coronal midpoint (LA point), was found to be constant among teeth of the same type. Variation in facial surface contour tended to be greater in the posterior teeth than in the anterior teeth. Future custom construction of brackets, adjusted to individual facial contour differences, will also require information regarding optimal tooth position in the head, including compensations necessary for variations in facial skeletal pattern.
测量了600颗上颌牙和下颌牙的面部表面轮廓，包括从正中切牙到第一磨牙每种类型的牙齿各50颗。同一类型牙齿在相同位置的面部轮廓、从咬合面/切缘到牙龈表面的面部轮廓以及冠部和根部纵轴形成的角度各不相同。所发现的变异程度非常大，这表明患者之间的差异或托槽放置高度的差异大于目前正畸中使用的标准扭矩处方之间的差异。在同一类型的牙齿中，没有发现包括冠中点（LA点）在内的任何一个点是恒定的。后牙的面部表面轮廓变异往往比前牙更大。未来根据个体面部轮廓差异定制托槽，还需要有关牙齿在头部最佳位置的信息，包括面部骨骼模式变化所需的补偿。
