Tikku Tripti, Khanna Rohit, Sachan Kiran, Agarwal Akhil, Srivastava Kamna, Yadav Pravesh
Department of Orthodontics and Dentofacial Orthopaedics, BBDCODS, Lucknow, Uttar Pradesh, India.
J Orthod Sci. 2013 Oct;2(4):124-9. doi: 10.4103/2278-0203.123199.
The objective of this study was to establish a new regression equation for North Indian and to compare and correlate the predicted width of unerupted canine and premolars obtained from the proposed regression equation of the present study in the North Indian population sample, Moyer's prediction table and also from Melgaco regression equation with the actual width; in order to check the applicability of various methods of mixed dentition analysis for the North Indian population.
The sample consisted of 200 dental casts obtained from the North Indian patients and students which consists of 100 males and 100 females with the average age of 20.12 ± 4.70 years for males and 19.54 ± 3.16 years for females. Mesiodistal tooth widths of mandibular arch from permanent right first molar to left first molar were measured with an electronic digital caliper. Student t-test was used for comparison and Pearson's correlation coefficient was used to correlate the actual sum and the predicted width of the permanent mandibular canines and premolars obtained from various methods.
The difference between the actual and predicted width was statistically insignificant using the regression equation obtained for the North Indian sample population (correlation r = 0.78) in contrast to the significant difference with predicted width obtained from Melgaco equation (r = 0.61) and Moyer's prediction table (r = 0.42).
A new proposed regression equation for the North Indian population was established. Amongst the three regression equations devised, the proposed regression equation formulated in the present study; gave the most accurate results confirming racial variation in tooth size. This method is considered as an easy and practical way to predict the size of unerupted canines and premolars.
本研究的目的是为北印度人群建立一个新的回归方程，并比较和关联从本研究针对北印度人群样本提出的回归方程、莫耶预测表以及梅尔加科回归方程得到的未萌出尖牙和前磨牙的预测宽度与实际宽度；以检验各种混合牙列分析方法对北印度人群的适用性。
样本包括从北印度患者和学生中获取的200个牙模，其中男性100名，女性100名，男性平均年龄为20.12±4.70岁，女性平均年龄为19.54±3.16岁。使用电子数字卡尺测量下颌弓从右侧第一恒磨牙到左侧第一恒磨牙的近远中牙宽度。采用学生t检验进行比较，并使用皮尔逊相关系数来关联从各种方法获得的恒下颌尖牙和前磨牙的实际总和与预测宽度。
与从梅尔加科方程（r = 0.61）和莫耶预测表（r = 0.42）获得的预测宽度存在显著差异相比，使用针对北印度样本人群获得的回归方程（相关系数r = 0.78）时，实际宽度与预测宽度之间的差异无统计学意义。
为北印度人群建立了一个新提出的回归方程。在设计的三个回归方程中，本研究制定的回归方程得出了最准确的结果，证实了牙齿大小存在种族差异。该方法被认为是预测未萌出尖牙和前磨牙大小的一种简单实用的方法。
