Distal Migration and Ectopic Eruption of the Mandibular First Premolar: Case Report.

Migration describes the movement of an unerupted tooth within the bone when normal eruption is prevented and the tooth leaves its normal site of development. This report describes a case of distal migration and ectopic eruption of the mandibular first premolar in an 8.5-year-old boy. Following early extraction of the primary second molar, the first premolar migrated distally through the extraction site of the primary second molar and erupted into occlusion just mesial of the permanent first molar.