[The rate of the eruption of human teeth. A review]

The speed that a tooth bud or growing tooth attains on its way to the level of occlusion merits biological and clinical interest. In this work, all data available in the literature related to the eruptive movement of the various permanent teeth in man, both prior and after their clinical emergence in the oral cavity, have been gathered and recalculated in rates of movement per day. For comparative purposes, the rates of migration of nonerupted teeth, of bone resorption and bone apposition, as well as the rate of elongation of growing tooth roots were also collected from the literature. The standardized data (rates in micron/day) revealed the intraosseous movements of tooth buds and growing teeth are dependent and limited in speed by the rates of bone resorption and bone apposition. The extra-alveolar movement of clinically visible tooth crowns on their course of prefunctional eruption occurs at a much higher speed which probably results from a combination of the rate of bone apposition in the apical region and the rate of root elongation. These findings are discussed in connection with our present knowledge on the mechanisms of tooth eruption.