Melgaço Camilo Aquino, de Sousa Araújo Mônica Tirre, de Oliveira Ruellas Antônio Carlos
Department of Orthodontics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Am J Orthod Dentofacial Orthop. 2007 Sep;132(3):340-5. doi: 10.1016/j.ajodo.2005.07.033.
Estimating the mesiodistal widths of unerupted permanent canines and premolars is an essential aspect of mixed dentition analysis. Several methods are used to predict tooth width. The best methods demonstrate high values of correlation and determination coefficients. In this study, we aimed to determine a linear regression equation that would predict the sum of the mesiodistal widths of mandibular permanent canines and premolars based on the sum of the widths of the 4 mandibular permanent incisors and first permanent molars.
The sample consisted of 500 dental casts, obtained from white Brazilian patients (250 male, 250 female; average ages, 13.8 and 14.4 years, respectively). Mesiodistal tooth widths were measured with an electronic digital caliper. Intraclass correlation coefficients were used to determine measurement consistencies. Paired and unpaired Student t tests were used to determine right/left side and sex differences, respectively. A paired Student t test was also used to compare the predicted and actual sums of the mandibular permanent canines and premolars.
We found high values of correlation (r) and determination (r2) coefficients, varying from r = 0.795 to r = 0.81, and r2 = 0.599 to r2 = 0.656. These values are among the highest described in the literature for nonradiographic prediction methods. On average, there was no difference between predicted and actual widths of the mandibular permanent canines and premolars, and the standard errors of estimation were 1.49 mm for males, 1.36 mm for females, and 1.44 mm for the total sample (considering right and left sides of the mandibular arch together).
The proposed method showed good accuracy and was easy to use, but it must be tested in other populations.
估计未萌出恒牙尖牙和前磨牙的近远中宽度是混合牙列分析的一个重要方面。有几种方法用于预测牙齿宽度。最佳方法显示出高相关系数和决定系数值。在本研究中，我们旨在确定一个线性回归方程，该方程可根据4颗下颌恒切牙和第一恒磨牙的宽度总和来预测下颌恒牙尖牙和前磨牙的近远中宽度总和。
样本包括500个牙模，取自巴西白人患者（男性250例，女性250例；平均年龄分别为13.8岁和14.4岁）。使用电子数字卡尺测量牙齿的近远中宽度。组内相关系数用于确定测量的一致性。配对和非配对学生t检验分别用于确定左右侧差异和性别差异。配对学生t检验还用于比较下颌恒牙尖牙和前磨牙的预测宽度总和与实际宽度总和。
我们发现相关系数（r）和决定系数（r²）值较高，r值在0.795至0.81之间，r²值在0.599至0.656之间。这些值是文献中描述的非放射学预测方法中最高的值之一。平均而言，下颌恒牙尖牙和前磨牙的预测宽度与实际宽度之间没有差异，男性的估计标准误差为1.49毫米，女性为1.36毫米，总样本（考虑下颌牙弓的左右两侧）为1.44毫米。
所提出的方法显示出良好的准确性且易于使用，但必须在其他人群中进行测试。
