To examine whether a talon incisor has an abnormal shape due to excess of dental hard tissues or pulp.
Two bilateral primary maxillary central incisors with talon cusp and a supernumerary mesiodens were removed from a 6-year-old boy. Histologically, 7 undecalcified cross sections (70 microm) were harvested from each talon tooth and from two regular primary central incisors of another child.
... [Show full abstract] Microradiographs of the sections were prepared and examined for enamel width, dentin width, pulp tissue area, and crown size (mesio-distal, labio-palatal) using Image Analysis.
No association to other developmental disorders was observed. The mean width of the enamel and dentin was similar in the talon and the regular incisors (difference 7.5% and 2.4%, respectively). The pulp area was greater in the talon teeth (37.4%). The latter had an effect on the increase in the mesio-distal and labio-palatal dimensions of the talon teeth (17.6% and 23.9%, respectively).
The fact that the talon cusp has normal enamel and dentin layers with a substantial enlarged pulp tissue suggests that similar developmental anomalies occur during tooth morphodifferentiation as in taurodontism and dens evagintus of premolars.