[Analysis of color changes of oral mucosa by smoking]

Smoking has various influences on oral mucosa, including color change. We quantitatively analyzed color changes of oral mucosa by smoking. To examine the influence of smoking over a wider age range, we measured the color of oral mucosa of 62 nonsmokers and 56 smokers (age 30-83 years). We measured color with a colorimeter by a perpendicular course, illuminating the measuring sites from a distance of 1 meter by artificial sunlight. Before measuring, we used standard white for calibration. We used the CIE L * a * b * colorimetric system for the color specification. The measured sites were the lips, gingiva, tongue and buccal mucosa. Before colorimetry, we examined the precision and repeatability of colorimeter, but the change was small. Moreover, we similarly examined the sex difference and age difference, but there was no significant difference. This study was approved by the Tokyo Medical and Dental University ethics screening committee. Among nonsmokers and smokers, a statistical difference was recognized in lips L *, a *, gingiva L *, a *, and buccal mucosa L *, b *. Smoking decreased the luminosity of the lips, gingiva, buccal mucosa and caused a blue coloration of gingiva and buccal mucosa.