Microcanals of dentin associated with maxillary primary anterior teeth

This study was performed to estimate the prevalence of giant dentin tubules or microcanals in primary maxillary anterior teeth.

One hundred sixty eight extracted or exfoliated primary maxillary anterior teeth were sectioned and examined by optical microscopy and image analysis. Differences in the proportion of teeth with microcanals among tooth types were tested by using the Pearson chi-square test.

Microcanals, having the appearance of enlarged dentin tubules, were found in approximately 20% of primary central and lateral incisors, but were significantly less prevalent (3%) in primary cuspids. Microcanals occurred in a mesial distal axial plane and ran between the DEJ and the pulp chamber. When present they numbered between 1 and 43, with mean numbers of 20 and 16 in central and lateral incisors, respectively. The microcanals ranged in size between 5 and 70 microns, compared to normal dentin tubule diameters of approximately 1 micron.

Microcanals are relatively common in primary maxillary incisors, but uncommon in primary cuspids. Additional work is needed to establish their prevalence in various teeth of both primary and permanent dentition.