Non-syndromic oligodontia in permanent dentition of monozygotic twins: Report of a rare case

Aim: To report a case of non-syndromic oligodontia involving 26 permanent teeth in monozygotic twin sisters and to discuss the possible genetic etiology, inheritance pattern and associated dental anomalies of this condition. Background: Hypodontia constitutes one of the most common developmental anomalies in humans and is defined as developmental absence of one or more teeth with reported prevalence of 1.6 to 9.6% in the permanent dentition. Oligodontia is defined as agenesis of six or more teeth excluding third molars. Case Report: This article describes a case of non-syndromic oligodontia involving 26 permanent teeth in monozygotic twin sisters. The twins had positive family history of hypodontia in their paternal grandmother, parental consanguinity (first cousin) and similarity in pattern of oligodontia. Root formation of permanent maxillary first molars and central incisors was delayed in both the twins. Summary: This article reports a case of nonsyndromic oligodontia in permanent dentition of monozygotic twins. Possible genetic etiology, inheritance pattern and associated dental anomalies are discussed. Clinical Significance: Strong genetic link associated with oligodontia help the dentist to know the possibility of its occurrence in other family members and in future generations.