Taurodontism in Brazilian patients with tooth agenesis and first and second-degree relatives: a case-control study

An association between tooth agenesis and taurodontism has been suggested. To verify if tooth agenesis and taurodontism are associated within families and specific patterns of tooth agenesis, this study aims to compare the frequency of taurodontism in patients with nonsyndromic familial tooth agenesis, their first and second-degree relatives with complete permanent dentition and a control group of unrelated healthy individuals with complete permanent dentition.

Panoramic radiographs of patients with nonsyndromic familial tooth agenesis, their first and second-degree relatives and a control group of individuals with complete permanent dentition were examined. Taurodontism was assessed on permanent mandibular first molars. The difference in the frequency of taurodontism among the studied groups was tested with Fisher's Exact Test.

Seventeen families with nonsyndromic familial tooth agenesis were studied. The frequency of taurodontism was 29% in patients with tooth agenesis, 10.3% in their first and second degree relatives, and 6.6% in the control group. A significant statistical difference among the studied groups was observed (p=0.002). Taurodontism was proportionally more frequent in patients with a higher number of absent teeth. It was mainly observed in patients from families in which the proband was diagnosed with oligodontia.

Taurodontism is more frequent in nonsyndromic familial tooth agenesis. Individuals in families with second premolar and molar oligodontia are more likely to have taurodontism, even the individuals with complete dentition. This association could define a subphenotype for future genetic studies of dental development.