Unintentional removal of a developing permanent premolar during primary molar extraction: a 10-year case report.

A 14-year-old girl underwent extraction of an ankylosed primary left second molar as requested by her orthodontist. The developing mandibular left second premolar (tooth 20) was unintentionally removed during extraction of the primary molar. Immediate measures were taken to reimplant tooth 20. Recall appointments over the next 10 years included monitoring of tooth 20. The patient also was followed up closely by her orthodontist during this time. Tooth 20 was monitored for proper eruption, root development, and pulpal vitality. The tooth erupted normally, and the results of pulp testing continued to be within normal limits over the course of 10 years (with the exception of a single higher electric pulp test reading than that for adjacent teeth). Root formation was completed and appeared to be within normal limits. Pulpal calcification also occurred. At the most recent recall, the tooth remained asymptomatic. Monitoring will continue during the patient's regular recall appointments. The success of this case 10 years after reimplantation supports quick action to optimize the potential for long-term clinical success. The fact that tooth 20 was at a developmental stage also likely had a favorable impact on the outcome of this case.