Late development of a mandibular second premolar

In this report, we present the case of a girl with delayed odontogenesis of a lower second premolar for which she was followed up for 8.5 years. Congenital absence of permanent mandibular second premolars was observed at the initial radiographic examination at 8 years and 1 month. One year later, during the treatment period, an unexpected odontogenesis of a right second premolar was diagnosed on follow-up radiography. The original treatment plan was revised and a new plan was successfully implemented. Th is unusual case showed that the orthodontist s clinical philosophy must be fl exible because unexpected situations can arise, especially when treating growing patients. [Korean J Orthod 2012;42(2):94-98]