Paediatrics: an unusual case of bilateral double teeth

I would like to share with you an unusual case of bilateral double teeth. In our community dental service, I was referred a 7-year-old boy for management of rampant caries in his posterior primary dentition. On examination, an incidental finding was two double teeth in his incisor region (Figure 1). These were asymptomatic and his mother reported a similar appearance to his primary teeth before they exfoliated.

Prevalence of double teeth is 0.5–1.6% in the primary dentition, which decreases to 0.1–0.2%¹ in the permanent dentition. As in this case, double teeth are most common in the anterior dentition and can be caused by gemination, fusion and twinning.^{2 Gemination occurs as a result of attempted division and fusion when two separate tooth germs have joined (namely the central and lateral incisors bilaterally), which seems to be the case in this situation. The aetiology of double teeth is unknown. Theories include environmental factors, trauma, systemic diseases, genetic factors or vitamin deficiencies.3}