Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Piracicaba, SP, Brazil.
J Esthet Restor Dent. 2012 Dec;24(6):402-14. doi: 10.1111/j.1708-8240.2012.00533.x. Epub 2012 Aug 15.
The purpose of this study was to assess the presence of the golden proportion (GP) in the facial view tooth-to-tooth width proportion of the six maxillary anterior teeth and to evaluate the width/height (W/H) ratios of the incisors of patients with maxillary lateral incisor (LI) agenesis treated either with implants or orthodontically (by moving canines into the position of the laterals, recontouring them, and placing composite restorations over the repositioned teeth).
Forty-eight patients with LI agenesis were divided into four experimental groups: unilateral recontouring group (N = 10), bilateral recontouring group (BRG, N = 18), unilateral implant group (UIG, N = 10), bilateral implant group (N = 10), and a control group (CG, N = 25) of patients without agenesis. GP ratios were determined on patients' dental casts placed over Levin's grids, whereas W/H ratios were measured directly on the casts and a millimeter ruler to determine these distances. Statistical analysis was performed with Shapiro-Wilk, Kruskal-Wallis, Mann-Whitney, Friedman, and Wilcoxon tests (p < 0.05).
The incidence of GP in the tooth-to-tooth width proportions was significantly different between groups and more commonly found between centrals and laterals than between laterals and canines. The GP was more likely to be observed in the BRG, UIG, and CG. The results demonstrated that the GP was not found to be present in the majority of the cases treated with maxillary agenesis, regardless of the method of treatment. The mean W/H ratios of the laterals ranged between 0.75 and 0.90.
Although the GP may be a useful diagnostic guide, it was not observed in the majority of esthetic outcomes of patients treated with maxillary LI agenesis in this study.
The assessment of the golden proportion and width/height ratio of upper anterior teeth in patients with upper lateral incisor agenesis treated with either implants or tooth re-contouring may assist dentists and patients in deciding the best treatment option based on the peculiarities of each case.
本研究旨在评估上颌六前牙牙面对牙宽度比例的黄金比例（GP）的存在，并评估上颌侧切牙（LI）缺失患者经种植或正畸（通过将尖牙移至侧牙位置、重新塑形并在重新定位的牙齿上放置复合修复体）治疗后的切牙的宽高（W/H）比值。
将 48 名 LI 缺失患者分为四个实验组：单侧再塑形组（N=10）、双侧再塑形组（BRG，N=18）、单侧种植组（UIG，N=10）、双侧种植组（N=10）和无缺失的对照组（CG，N=25）。在 Levin 网格上放置患者牙模后确定 GP 比值，而 W/H 比值则直接在牙模和毫米尺上测量以确定这些距离。采用 Shapiro-Wilk、Kruskal-Wallis、Mann-Whitney、Friedman 和 Wilcoxon 检验进行统计学分析（p<0.05）。
各组间牙对牙宽度比例的 GP 发生率差异有统计学意义，且中央牙和侧牙之间的 GP 发生率高于侧牙和尖牙之间的 GP 发生率。BRG、UIG 和 CG 更可能观察到 GP。结果表明，无论治疗方法如何，上颌缺失的大多数病例均未发现 GP。侧牙的平均 W/H 比值在 0.75 至 0.90 之间。
尽管 GP 可能是一种有用的诊断指南，但在本研究中，上颌 LI 缺失患者的大多数美学效果中均未观察到 GP。
评估上颌侧牙缺失患者经种植或牙再塑形治疗后的上颌前牙 GP 评估和宽高比，可能有助于牙医和患者根据每个病例的特点选择最佳治疗方案。
