Eruption of a permanent mandibular canine in a 5-year-old boy.

The premature eruption of a mature mandibular permanent canine is described in a healthy 5-year-old boy with developmental absence of the primary predecessor. The effects of early loss or missing primary teeth on eruption timing of the permanent successors are discussed. The very early maturation of the permanent canine appears to be a unique oddity, and there are no reports in the literature of eruption of this type of secondary tooth at such an early chronological age.