Fusion presenting as gemination;rare case report

Gemination is a developmental anomaly of form ,which is recognized as an attempt by single tooth germ to divide resulting in a large tooth with a bifid crown &usually a common root and root canal in which the teeth count is normal when the anomalous tooth is counted.

Fusion is recognized as union of two separate tooth buds during odontogenesis,therefore one fewer tooth than normal in the dentition if the affected tooth is counted as one.

Case report: An 11 years old boy appeared in my clinic for examination. During intra oral diagnostics, tooth # 8 was not erupted yet. Clinically, it was revealed an abnormal maxillary temporary incisor retained in the mouth;two crowns joined togther. A provisional diagnosis  of gemination was given since the teeth count is normal. Radiographically, two fused  crowns with seperate roots and root canals were seen,along with a supernumerary tooth preventing the central incisor from erupting. A diagnosis of two temporary anomalous teeth fused together conjoined with a peg shaped anomalous supernumerary tooth embedded between the central permanent incisor and the temporary milk tooth.

A decision was made to surgically  extract the temporary tooth along  with the impacted peg shaped supernumerary tooth to give a way to the central permanent incisor to erupt.

**N.B. Normally,Maxillary central incisors begin to erupt at the age of 6. In this case the eruption of maxillary permanent right central incisor was delayed.