PAX9 and tooth agenesis: Although the aetiology of dental anomalies is still not quite clear, it has been demonstrated in the last decade that genetic factors play a major role in dental agenesis, with mutations in MSX1 and PAX9 genes having been associated with non-syndromic tooth agenesis in humans within and outside the cleft area,10,11,12 causing the combined development of orofacial clefts and hypodontia.13,14