Sir, a 23-year-old male patient presented to our clinic for removal of the left mandibular third molar after several episodes of acute pericoronitis. Intraorally the tooth appeared to be of normal morphology and was partially erupted. However, a panoramic radiograph showed what appeared to be a supernumerary tooth superimposed over the left mandibular third molar (Fig. 1). A surgical extraction was performed and the tooth was removed completely intact. Inspection of the specimen extra orally found that there were two crowns and four roots which we diagnosed as fusion of a supernumerary tooth to the left mandibular third molar. The tooth was fused at the dentine and the pulp chambers were connected, suggesting that fusion occurred early in development.

Fig. 1
figure 1

Cropped panoramic radiograph showing as if supernumerary tooth superimposed over the left mandibular third molar

Full size image

A rare fusion variant of this kind is of interest to a general dentist because of its clinical implications. Although a majority of fused teeth are asymptomatic and require no treatment, some may cause issues such as crowding, impaction, and periodontal conditions. Accurate diagnosis and careful radiographic evaluation are important to achieve a successful clinical outcome.