Talebi Maryam, Parisay Iman, Sarraf Ali, Mazhari Fateme
Department of Pedodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Iran.
J Contemp Dent Pract. 2010 Oct 14;11(5):033-40.
The aim of this pilot study was to evaluate equations for predicting the size of unerupted canines and premolars during the mixed dentition period in an Iranian population.
This cross-sectional analysis was performed on 106 subjects (52 girls, 54 boys, aged 13-15 years). Data were obtained from dental cast by making direct measurements of the maximum mesiodistal widths of all mandibular and maxillary incisors, canines, premolars, and first molars with an electronic digital sliding caliper, with an accuracy of ± 0.02 mm and repeatability of ± 0.01 mm. The results were statistically analyzed using Student t tests, Pearson product-moment coefficients, and ANOVA tests. Correlation coefficients (r) and error variance of estimates were determined using a significance level of p<0.05.
No significant differences were found between the mesiodistal tooth widths of males and females in this Iranian population. The highest correlation was between the sum of the mesiodistal width of canines and premolars in the maxilla with the mesiodistal width of the mandibular first molars and maxillary central incisors (r = 0.742). A moderate correlation was obtained in the mandible (r = 0.665). Approximations were developed to predict the size of the unerupted canines and premolars in both jaws (in the maxilla, Y = 0.740X + 14.271, or the simplified formula, Y = 3/4X + 14; for the mandibular arch, Y = 0.658X + 16.353, or the simplified formula, Y = 2/3 X + 16).
The strongest correlation was found for the sum of the mesiodistal width of canines and premolars in the maxilla with the mesiodistal width of the mandibular first molars and maxillary central incisors in the maxillary analysis (r = 0.742). A moderate correlation was found in the mandible for the sum of the mesiodistal width of canines and premolars with the mesiodistal width of the mandibular first molars and maxillary central incisors (r = 0.665).
The simplified equations proposed for the maxillary arch (Y = 3/4 X + 14) and for the mandibular arch (Y = 2/3 X + 16) offer an easy and practical way to predict the size of unerupted canines and premolars in the maxillary and mandibular arches of Iranian children.
本初步研究旨在评估用于预测伊朗人群混合牙列期未萌出尖牙和前磨牙大小的公式。
对106名受试者（52名女孩，54名男孩，年龄13 - 15岁）进行了横断面分析。通过使用电子数字游标卡尺直接测量所有下颌和上颌切牙、尖牙、前磨牙及第一磨牙的最大近远中宽度，从牙模获取数据，该卡尺精度为±0.02毫米，重复性为±0.01毫米。使用学生t检验、皮尔逊积矩系数和方差分析对结果进行统计学分析。相关系数（r）和估计误差方差的确定采用p<0.05的显著性水平。
在该伊朗人群中，男性和女性的牙齿近远中宽度未发现显著差异。在上颌中，尖牙和前磨牙近远中宽度之和与下颌第一磨牙及上颌中切牙的近远中宽度之间相关性最高（r = 0.742）。在下颌中获得了中等相关性（r = 0.665）。开发了近似公式来预测上下颌未萌出尖牙和前磨牙的大小（在上颌中，Y = 0.740X + 14.271，或简化公式，Y = 3/4X + 14；在下颌牙弓中，Y = 0.658X + 16.353，或简化公式，Y = 2/3X + 16）。
在上颌分析中，尖牙和前磨牙近远中宽度之和与下颌第一磨牙及上颌中切牙的近远中宽度之间相关性最强（r = 0.742）。在下颌中，尖牙和前磨牙近远中宽度之和与下颌第一磨牙及上颌中切牙的近远中宽度之间发现中等相关性（r = 0.665）。
为上颌牙弓（Y = 3/4X + 14）和下颌牙弓（Y = 2/3X + 16）提出的简化公式为预测伊朗儿童上颌和下颌牙弓中未萌出尖牙和前磨牙的大小提供了一种简单实用的方法。
