Ajami Shabnam, Fattahi Hamidreza, Zare Mahsa, Jenabi Peyman
DMD, MScD., Assistant Professor of Orthodontics, Othodontic Research Centre, Department of Orthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
DMD, MScD., Orhodontic Research Centre, Orthodontist, Private Practice, Shiraz, Iran.
Electron Physician. 2018 Mar 25;10(3):6454-6461. doi: 10.19082/6454. eCollection 2018 Mar.
Bolton's two main ratios describing the proportional size of upper and lower teeth, could contribute to estimating the excess or deficiency of tooth size necessary to obtain an ideal occlusion. However, the mean Bolton values are not the same among different societies. Determining the prevalence of tooth size deviations from population-specific Bolton indices might help local orthodontists to have a more concise treatment plan.
The study aimed to define the prevalence of clinically significant tooth size discrepancies (TSD) in an Iranian population and to evaluate the influence of lateral incisors' size on this discrepancy.
This cross-sectional study was conducted on study casts of orthodontic patients attending Imam Reza Dental Clinic from September 2008 to December 2016. The sample comprised of 150 randomly selected pre-treatment study casts (64 males and 86 females from 17 to 28). The mesiodistal diameter of all permanent teeth from the first molar on the right to the first molar on the left was measured using 2 similar digital calipers, and Bolton analysis was calculated. Subjective visual estimation of Bolton discrepancy was also performed. SPSS v18.0, Wilcoxon signed ranks test, Pearson correlation and Receiver Operating Characteristic (ROC) curve analysis were used for statistical analysis. A p<0.05 was considered statistically significant.
In the sample group, 34.7% had anterior Bolton index (ABI) and 20.7% had total Bolton index (TBI) greater than 2 Standard Deviations (2SDs) of Bolton's means, and about half of them required correction of the ABI considering the actual size of discrepancies (mm). The sensitivity of estimating clinically significant tooth size discrepancy more than 2SDs of Bolton's ABI and the visual judgment was 96.0% and a cut-off point of -0.12mm was obtained.
Bolton's analysis should be routinely performed in all orthodontic patients, and visual estimation of TSD would be suggested as a screening method in the first visit prior to measurements and set-ups.
博尔顿描述上下牙齿比例大小的两个主要比率，有助于估计获得理想咬合所需牙齿大小的过剩或不足。然而，不同社会群体的博尔顿均值并不相同。确定偏离特定人群博尔顿指数的牙齿大小偏差患病率，可能有助于当地正畸医生制定更精确的治疗方案。
本研究旨在确定伊朗人群中具有临床意义的牙齿大小差异（TSD）的患病率，并评估侧切牙大小对这种差异的影响。
本横断面研究对2008年9月至2016年12月在伊玛目礼萨牙科诊所就诊的正畸患者的研究模型进行。样本包括150个随机选择的治疗前研究模型（64名男性和86名女性，年龄17至28岁）。使用2个类似的数字卡尺测量从右侧第一磨牙到左侧第一磨牙的所有恒牙的近远中径，并进行博尔顿分析。还对博尔顿差异进行了主观视觉估计。使用SPSS v18.0、威尔科克森符号秩检验、皮尔逊相关性和受试者工作特征（ROC）曲线分析进行统计分析。p<0.05被认为具有统计学意义。
在样本组中，34.7%的患者前牙博尔顿指数（ABI）和20.7%的患者全牙博尔顿指数（TBI）大于博尔顿均值的2个标准差（2SDs），考虑到实际差异大小（mm），其中约一半患者需要矫正ABI。估计博尔顿ABI大于2SDs的具有临床意义的牙齿大小差异和视觉判断的敏感性为96.0%，获得的截断点为-0.12mm。
所有正畸患者都应常规进行博尔顿分析，在测量和排牙前的首次就诊时，建议将TSD的视觉估计作为一种筛查方法。
