A radiographic study of dental eruption.

The process of eruption of five mandibular teeth was studied radiographically on the annual cephalograms of fifty-four boys and forty-one girls from the ages of 3 to 14 years. It was found that following completion of the crown the teeth moved toward the occlusal plane at a uniform rate until the preocclusal eruption surge of 4 to 7 mm. per year. It was also found that the rapid eruption phase does not correlate with root length increase in which eruption exceeded root growth by as much as 4.6 mm. per year. A significant eruption rate was demonstrated at age 14; the mandibular second molar continued to erupt at approximately three times the rate of the mandibular canines. this suggested rotation of the occlusal plane in relation to the mandibular tangent.