Spectrophotometric dental colour measurement to assess age in living adults

Abstract

The aim of this study was to evaluate the usefulness of spectrometrically measured colour parameters of teeth for age estimation in living adults. A total of 329 teeth were selected (162 upper central incisors and 167 upper canines) from 52 men and 50 women aged between 20 and 86 years. Colour measurements were performed in vivo on the vestibular surface of the teeth using a portable contact Spectro-color device. Colorimetric variables (L*, a*, b*), chromaticity coordinates (x, y, z), and indexes of whiteness (WIC, Z%, WI) and yellowness (YI) were calculated. The accuracy of colour values to estimate the age was determined by Receiver Operating Characteristic analysis. A more powerful age discrimination was obtained with upper incisors than with upper canines. Areas under the ROC curve ranged from 0.7 to 0.8 for all dental colour parameters measured in upper central incisors except for the variables L* and Z%, with sensitivity values ranging from 56% to 93% and specificity values from 38% to 92%. We conclude that spectrophotometric dental colour measurement may be an objective and useful tool to estimate age and meets medical ethical standards for application in living adults. However, further research is needed to study the effect of ethnicity and other factors on tooth colour.