Methods: Touch and pain thresholds of 50 healthy elderly (26 males, 24 females, mean age 77±4.6) were compared with those of 50 young subjects (24 males, 26 females, mean age 27±2.5). Subjects lay in the supine position on a dental chair with their eyes closed. The Semmes-Weinstein Pressure Aesthesiometer was slowly applied vertically to 9 points in the oral region and 4points in the hands; the dorsum manus, the palma manus, the incisive papilla, the palatal mucosa, the buccal mucosa, and the dorsum of tongue. We measured the pain thresholds 30 seconds after the measurement touch thresholds. We made one trial on each test site on the same day. The difference of the thresholds between young and elderly subjects was statistically evaluated by Mann-Whitney U-test.
Results: Elderly subjects showed significantly higher touch thresholds than those of young subjects in the palma manus (right and left), the incisive papilla, and the dorsum of tongue (right, left and center) (P<0.05). The pain thresholds of elderly subjects were significantly lower than those of young subjects in the buccal mucosa (right and left), the palatal mucosa (right and left) and the tongue edge (right and left) (P<0.05).
Conclusion: The touch thresholds of the oral mucosa increased with age while the pain thresholds decreased with age. It seemed that this change was due to a decrease in the Meissner's corpuscles, morphological shrinkage with age, and a decrease in the thickness of the mucosal epithelium within the lining mucosa and the masticatory mucosa.