Supernumerary premolars: a literature review

Supernumerary premolars appear to be more common than previously estimated. The purpose of this report was to review most of the cases published in the dental literature since 1932. The authors found that supernumerary premolars occur 3 times more in males than in females, indicating a possible sex-linked inheritance, with the highest frequency of occurrence in the mandibular premolar region (74%). They are also the most common supernumerary teeth in the mandibular arch (7%), and their incidence is 1% (1 in 157)-much higher than previously reported. Maxillary supernumerary premolars were found to occur at a lower rate (26%). The possible mechanisms of development are described, with a localized hyperactivity of the dental lamina being the most widely accepted theory. Recurrence of supernumerary premolars after being surgically removed has been reported in 8% of the cases reviewed. Patients with a previous history of anterior conical or tuberculated supernumerary teeth at an early age have a 24% possibility of developing single or multiple supernumerary premolars at a later age. Early diagnosis and appropriate follow-up with panoramic radiographs is extremely important. Various treatment recommendations are also discussed.