Naidu Devan, Scott Justin, Ong Desmond, Ho Christopher T C
School of Dentistry, The University of Queensland, Brisbane, Australia.
Aust Orthod J. 2009 Nov;25(2):97-103.
Vernier calipers have traditionally been used as the 'gold-standard' for tooth width measurements. New digital methods may prove to be as valid, reliable and reproducible as caliper measurements.
To determine the validity, reliability and reproducibility of mesiodistal crown measurements made with calipers, using the DigiModel method and on digital photographs, and to determine the validity, reliability and reproducibility when the measurements are employed in Bolton tooth size analyses.
Twenty-five consecutive study models were used. The maximum mesiodistal crown widths of 12 teeth in each arch (first molar to first molar) were measured with digital calipers, using the DigiModel software (OrthoProof, Caulfield South, Victoria, Australia) and on standardised digital photographs of the models by eight examiners. One examiner measured all models three times using the three measurement methods, two examiners measured all models once using the three measurement methods and five examiners measured all models once using the calipers only. Validity for the widths of individual teeth, the mean tooth width and the Bolton ratios were assessed using a general linear model two-way analysis of variance and pair-wise comparisons between the two digital methods and the calipers. Reliability was assessed with Cronbach's alpha and reproducibility with the intra-class correlation coefficient.
There were statistically significant differences between the tooth widths measured with DigiModel and the calipers (p < 0.001) and with the calipers and digital photographs (p < 0.001). However these discrepancies were judged not to be clinically significant. The Cronbach's alpha scores for all methods were classified as 'excellent'. The intra-class correlation coefficient values exceeded 0.75 for the digital calipers, 0.79 for DigiModel and 0.54 for the digital photographs.
The validities of DigiModel and digital photographs for tooth width measurements and Bolton analyses are clinically acceptable. The reliability of both methods is also excellent. However, DigiModel software provided more accurate Bolton's ratios and demonstrated greater reproducibility than the digital photographs.
游标卡尺传统上一直被用作测量牙齿宽度的“金标准”。新的数字方法可能被证明与卡尺测量一样有效、可靠且可重复。
确定使用卡尺、DigiModel方法以及在数码照片上进行近远中牙冠测量的有效性、可靠性和可重复性，并确定在博尔顿牙齿大小分析中使用这些测量方法时的有效性、可靠性和可重复性。
使用连续的25个研究模型。八位检查者使用数字卡尺、DigiModel软件（OrthoProof，澳大利亚维多利亚州考菲尔德南区）以及模型的标准化数码照片，测量每个牙弓中12颗牙齿（第一磨牙至第一磨牙）的最大近远中牙冠宽度。一位检查者使用三种测量方法对所有模型测量三次，两位检查者使用三种测量方法对所有模型各测量一次，五位检查者仅使用卡尺对所有模型各测量一次。使用一般线性模型双向方差分析以及两种数字方法与卡尺之间的成对比较，评估单个牙齿宽度、平均牙齿宽度和博尔顿比率的有效性。使用Cronbach's alpha评估可靠性，使用组内相关系数评估可重复性。
用DigiModel测量的牙齿宽度与用卡尺测量的结果之间（p < 0.001）以及用卡尺测量与数码照片测量的结果之间（p < 0.001）存在统计学显著差异。然而，这些差异被判定为在临床上不显著。所有方法的Cronbach's alpha分数均被归类为“优秀”。数字卡尺的组内相关系数值超过0.75，DigiModel为0.79，数码照片为0.54。
DigiModel和数码照片用于牙齿宽度测量和博尔顿分析的有效性在临床上是可接受的。两种方法的可靠性也都非常出色。然而，DigiModel软件提供了更准确的博尔顿比率，并且比数码照片具有更高的可重复性。
