Comparing Skin Tones to Shades of Upper Anterior Teeth: An Observational Study among Nigerian Adults

Background: Skin tones may be predictive of anterior tooth shade. An analysis of the relationship of skin tone to anterior tooth shade within a population may facilitate the prescription of complete dentures with optimal esthetics and realism. Aim: This study aimed to assess the relationship between skin tones and shades of upper anterior teeth among a diverse Nigerian adult population. Methods: The study was conducted between February and December 2022 among consecutive healthy adults recruited from dental clinics of five teaching hospitals in four cities located across four geopolitical zones of Nigeria. Skin tones were recorded using the National Immigration Service (NIS) Skin Color scale. The Vitapan Classic (R) shade guide was used to record the tooth shade of the upper central incisors and canines. Bivariate and multivariate tests of associations were performed, and predictive probabilities were developed. Results: A total of 1070 adults with a mean age of 30.8 +/- 10 years participated in the study. NIS skin tones 6 (29.8%) and 5 (27.7%) were the most common, while hues A (48.7% in incisors and 48.4 % in canines) and B (41.1% in incisors and 40.1% in canines) were predominant. The values of the incisors and canines were positively related to skin tone (P = 0.001) and age (P = 0.001 for incisors and P = 0.003 for canines). Hue was also significantly associated with skin tone for canines (P = 0.01) and gender (P = 0.001). Regression models showed increasingly darker skin tones were positively related to duller values for incisor teeth (beta = 0.173, OR =1.19, P < 0.001). The values for canines were more likely to be >2 (beta = 0.118, OR =1.12, P = 0.01), but without significant positive relationship to increasingly darker skin tones (beta = -0.99, OR =0.91, P = 0.22). Conclusion: Skin tones were associated with upper anterior tooth shade. There was a positive relationship between skin tones and the shades of upper anterior teeth. Skin tones could guide the clinician in shade selection during complete denture prescriptions.