µCT evaluation of apical delta morphologies in dogs’ canine teeth

Small terminal branches of the root canal in mammals can form a so-called apical delta (AD). Morphological configuration and variability of this apical canal system can affect endodontic treatment success. Although ADs are more prevalent in permanent dentition of dogs than in humans, little is known about 3D appearance and complexity. The present study offers novel virtual insights into dog AD morphologies using high-resolution µCT and AMIRA image visualization and analysis software. Detailed scans of 21 permanent canine teeth of 15 dogs were made.
The isotropic voxel size of reconstructed volumes was 6 μm or 10 μm for small or medium and large breed dogs, respectively. All teeth showed a clear AD with either broad or narrow radial or laterally compressed branching pattern. The vertical extension markedly increased with body weight (1.42 – 5.91 mm). 72.2 % of ADs had more than 20 ramifications (6 – 233). The diameter of individual apical foramina ranged from 14 – 461 µm. The distribution of foraminal diameters varied with body weight, p  10 kg in favor of larger diameters, p  0.002. These data indicate a high morphological variability of ADs in dogs' canine teeth, at once emphasizing the necessity for a more targeted endodontic treatment.