Ross V A, Isaacson R J, Germane N, Rubenstein L K
Department of Orthodontics, School of Dentistry, Medical College of Virginia, Richmond.
Am J Orthod Dentofacial Orthop. 1990 Nov;98(5):422-9. doi: 10.1016/S0889-5406(05)81651-8.
Control of faciolingual tooth inclinations is obtained by using rectangular wire with third-order bends and standard edgewise brackets or by using a straight wire in a preadjusted appliance system. Ideal faciolingual inclinations have been determined previously by measuring facial surface contours relative to coronal long axes. This study evaluates faciolingual inclinations based on occlusal table inclinations relative to occlusal planes. The samples compared include untreated ideal occlusions and malocclusions in three different vertical skeletal growth patterns. Faciolingual inclinations of first molars and central incisors were measured relative to the occlusal plane and to selected cephalometric angular measurements. Statistical comparisons between groups revealed significant differences in the inclinations of the upper incisor relative to the occlusal plane (U1-OP) and the inclination of the occlusal plane relative to sella nasion (OP-SN). No statistically significant intergroup differences were found in the inclination of the lower incisor relative to the occlusal plane (L1-OP) or in the faciolingual inclinations of the maxillary and mandibular first molars. On the basis of the large intergroup differences in the mean angle between the occlusal plane and sella nasion (OP-SN), the use of straight-wire appliance therapy is discussed in terms of the potential for creating differential moments. Because differential moments may facilitate or hinder treatment goals, the practitioner must know the biomechanical sequelae resulting from occlusal plane-sella nasion variations, which differ from normative values when preadjusted brackets are used.
通过使用带有三阶弯曲的矩形弓丝和标准方丝弓托槽，或在预调整矫治器系统中使用直丝，可以控制牙齿的颊舌向倾斜度。理想的颊舌向倾斜度先前已通过测量相对于牙冠长轴的面部表面轮廓来确定。本研究基于相对于咬合平面的咬合面倾斜度来评估颊舌向倾斜度。所比较的样本包括三种不同垂直骨骼生长模式下未经治疗的理想咬合和错牙合。相对于咬合平面以及选定的头影测量角度，测量了第一磨牙和中切牙的颊舌向倾斜度。组间的统计比较显示，上颌切牙相对于咬合平面的倾斜度（U1-OP）以及咬合平面相对于蝶鞍鼻根点的倾斜度（OP-SN）存在显著差异。在下颌切牙相对于咬合平面的倾斜度（L1-OP）或上颌和下颌第一磨牙的颊舌向倾斜度方面，未发现组间有统计学意义的差异。基于咬合平面与蝶鞍鼻根点之间平均角度的组间巨大差异，从产生差异力矩的可能性方面讨论了直丝矫治器治疗的应用。由于差异力矩可能促进或阻碍治疗目标，从业者必须了解因咬合平面 - 蝶鞍鼻根点变化而产生的生物力学后果，当使用预调整托槽时，这些后果与标准值不同。
