The degree to which dental attrition in modern society is a function of age and of canine contact.

Dental attrition ranked according to a validated severity scale correlated with age as a proxy for functional wear in 148 asymptomatic subjects. Anterior, posterior, mediotrusive, laterotrusive, and total attrition severity was analyzed. The geometric contribution of canine attrition to the variance of posterior attrition was also tested through correlations, and the time span required to record a statistically significant difference in attrition using the scale was determined. Age explained 12.6% of the differences the total attrition scores (P < .001, Spearman's rho), 6.4% of the anterior scores (P < .01), and 20.9% of the laterotrusive scores (P < .0001). Canine wear in subjects aged 20 to 49 years explained between 20% to 34% of the posterior attrition (P < .05 to P < .001), 6% to 36% of the mediotrusive attrition (P < .05 to P < .01), and 20% to 29% of the laterotrusive attrition (P < .05 to P < .001). At least 20 to 30 years was necessary to show significant clinical differences, except that laterotrusive attrition changes could be discriminated in only 10 years for the 20- to 29-year-old group. Notable attrition was already evident in the 20- to 29-year-olds, and accelerated wear rates prior to age 20 years were not maintained in most areas of the dentition. A nonlinear progression with age was observed, thereby inhibiting prediction of subsequent attrition from prior levels. Attrition was concluded to have multifactorial etiology, with age and the geometry of canine guidance having a significant influence, in addition to commonly accepted parafunction.