Durgekar Sujala Ganapati, Naik Vijay
Department of Orthodontics and Dentofacial Orthopedics, K.L.E's Vishwanath Katti Institute of Dental Sciences, KLE University, J.N.M.C. Campus, Nehru Nagar, Belgaum, Karnataka, India.
Indian J Dent Res. 2009 Jan-Mar;20(1):26-30. doi: 10.4103/0970-9290.49056.
The purpose of this study is to test the reliability of Moyers mixed dentition analysis in school children.
A study was conducted on a sample of 150 school children within the age group of 13 to 16 years old who had all permanent teeth that were fully erupted. Dental impressions were taken with alginate impression material and immediately poured with dental stone. Mesiodistal dimensions of permanent mandibular incisors, maxillary and mandibular canines, and premolars were measured using a digital caliper with a resolution of 0.01 mm.
The coefficient of correlation (r) was calculated to find the correlation between the sums of the canine, premolars in both arches, and mandibular incisors. A Student's unpaired t test was calculated to compare the tooth dimension between male and female subjects. The actual measurements were compared with the predicted values obtained with the Moyers prediction tables at the 35 th , 50 th , and 75 th percentile confidence levels. A Student's t test was calculated to compare the actual and predicted values. Using this data, linear regression equations were formulated for tooth size prediction. The coefficient of determination [r2] was calculated to find the accuracy of the formulated prediction equations. The standard error of estimate (SEE) was calculated to determine the validity of the proposed equations.
Moyers prediction tables are not an accurate method to estimate tooth dimension in our samples. The mesiodistal crown dimension in the buccal segment of the mandibular arch was larger in males (p=0.04) than in females.
The differences noted between predicted values from the Moyers tables and that of the present investigation is the result of racial and ethnic diversity. The accuracy of the prediction equation should be tested in a larger sample.
本研究旨在检验莫耶斯混合牙列分析法在学龄儿童中的可靠性。
对150名年龄在13至16岁之间、恒牙全部萌出的学龄儿童样本进行了研究。用藻酸盐印模材料制取牙印模，并立即灌注石膏模型。使用分辨率为0.01毫米的数字卡尺测量下颌恒切牙、上颌和下颌尖牙以及前磨牙的近远中径。
计算相关系数（r）以找出双侧牙弓尖牙、前磨牙与下颌切牙总和之间的相关性。计算学生氏非配对t检验以比较男性和女性受试者的牙齿尺寸。将实际测量值与通过莫耶斯预测表在第35、50和75百分位数置信水平下获得的预测值进行比较。计算学生氏t检验以比较实际值和预测值。利用这些数据，制定牙齿大小预测的线性回归方程。计算决定系数[r2]以确定所制定预测方程的准确性。计算估计标准误差（SEE）以确定所提出方程的有效性。
在我们的样本中，莫耶斯预测表不是估计牙齿尺寸的准确方法。男性下颌牙弓颊侧段的近远中冠径大于女性（p = 0.04）。
莫耶斯表预测值与本研究结果之间的差异是种族和民族多样性的结果。应在更大的样本中检验预测方程的准确性。
