Avaliação da variação da proporção áurea de acordo com o tipo facial esquelético e dos tipos de relação molar por meio de telerradiografias laterais de face: estudo de uma população do Nordeste do Brasil

Abstract

Beauty is a standard that has been sought for a long time, and the golden ratio can be a factor that seeks esthetic proportionality in different facial types trying to correlate dentistry and smile esthetics and facial harmonization. The aim of this study was to evaluate the variation in craniofacial proportions among themselves, according to golden ratio, related to the different facial types, and also compare those findings by comparing variations in the Ricketts molar relationship and genders. The sample consisted of lateral facial cephalograms, provided by a private dental imaging diagnostic clinic located in Fortaleza – CE. Based on previous study by Ono et al. (2007), it was estimated necessary to evaluate 45 face teleradiographies in order to obtain a sample that represents 80% power and 95% confidence. Inclusion criteria were: patients aged between 17 and 25 years with all permanent teeth present, not considering the third molars, and not previously submitted to any orthodontic treatment. After initial analysis, the sample was then divided into 3 distinct groups following the facial types according to VERT Ricketts study (Brachyfacial, Mesofacial and Dolichofacial) and molar relationship. For the analysis of the golden proportion, cephalometric analyzes were performed using the Radiocef 4.0 program using nine different proportions (P1 to P9) calculated from the measurement of the distance between cefalometric points. To assess the presence of divine proportion in cephalometric proportions, data were tabulated and based on the following concept: “A pair of measurements (A, B) is in divine proportion if A/B = 1.618, which A>B”. Data normality was assessed using the Shapiro-Wilk test. Student's t test was performed for statistical analysis between genders and Kruskal-Wallis and ANOVA tests with Tukey post hoc to compare data obtained from the proportions evaluated according to the different facial types, sub-grouped according to the molar relationship of Ricketts. For all tests, a significance level of 5% was used. In the analysis of craniofacial proportions according to gender, only P1 (Or-Me/Ena-Enp) showed a statistically significant difference (p<0.01), maintaining this statistical pattern when comparing the different facial types. In the same analysis, P2 (Or-Me/A-Pog) also showed results that differed in the brachy and dolichofacial groups. When the data were analyzed intragroups, the molar ratio was the dependent variable analyzed, with statistically significant differences found in proportions P9 (CC-Gn/CC-Go; p = 0.001) in mesofacial individuals and P7 (Ena-AA/N -Ena; p < 0.05) for dolichofacials. Hormonal influences due to gender may have influenced the statistically significant findings and the Ricketts molar ratio factor seems to have little influence on the craniometric proportions evaluated. In general, most of the evaluated proportions approached the golden proportion.