Bilateral fusion of primary mandibular lateral incisors and canines: a report of a rare case

Fusion is commonly identified as the union of two distinct dental sprouts, which may occur in any stage of the dental organ. Teeth are joined by the dentin region; pulp chambers and canals may be linked or separated depending on the developmental stage when the union occurs. This process involves epithelial and mesenchymal germ layers resulting in irregular tooth morphology. Moreover, the number of teeth in the dental arch is reduced. The literature shows controversial concepts to correctly differentiate between teeth fusion and gemination. For a differential diagnosis between these anomalies, the dentist must carry out a highly judicious radiographic and physical examination.

Prevalence of fusion of tooth is about 0.5-2.5% in the primary dentition with a lower prevalence in permanent dentition. The aetiology of fusion is still unknown, but the influence of pressure or physical forces producing close contact between two developing teeth has been reported as one possible cause. Genetic predisposition and racial differences have also been reported as contributing factors.