Mandibular canines with additional roots: An ex vivo study of the external and internal morphology

Abstract

The aim of this study was to investigate the root and root canal morphologies of mandibular canines with additional roots using cone-beam computed tomography. Seventy-seven extracted two-rooted and one-three-rooted permanent human mandibular canines were selected. Aspects of the external morphology evaluated were crown length, root length, total length, root bifurcation distance from the cementoenamel junction, root size, and direction of the root curvature in the apical third. Features of internal morphology assessed were root canal number per root, root canal bifurcation distance from the cementoenamel junction, and the angle between the buccal or lingual canal and the main canal. The root size and length presented considerable diversity. Most of the roots bifurcated at the middle third and exhibited a buccal curvature. The main root canal bifurcated coronally in two root canals, a buccal and a lingual. The majority of the buccal and lingual root canal angles were blunt. The presence of a third root in a specimen was a novel finding of this study.

Endodontic retreatment of mandibular canines with two roots: A report of two cases

“…6 Regarding wideness, two studies have reported that the buccal root was larger than the lingual root in 47.7% and 41.5% of teeth. 14,15 On the other hand, another study found the same prevalence of lingual roots larger than buccal roots (36.0%) and buccal roots larger than lingual roots (36.0%). 16 These studies also found 43.1%, 35.1%, and 28.0% of mandibular canines with equal-sized roots.…”

“…[11][12][13] In both cases, the two-rooted mandibular canines had two canals, one in each root, in agreement with several studies. 8,9,[14][15][16] They were classified as type V according to Vertucci, 12 and coded as 2 33 1 B 1 L 1 according to Ahmed's system. 17 Mandibular canines with two roots are generally shorter than single-rooted canines.…”

“…16 These studies also found 43.1%, 35.1%, and 28.0% of mandibular canines with equal-sized roots. [14][15][16] Root bifurcation has been reported as more prevalent (45.4%, 81.2%, and 58.0%) in the middle third 6,14,16 and common in the apical third (35.1% and 44.0%). 14,16 However, one study found bifurcation in the apical third to be more prevalent (56.9%), followed by the middle third (40%).…”

“…[14][15][16] Root bifurcation has been reported as more prevalent (45.4%, 81.2%, and 58.0%) in the middle third 6,14,16 and common in the apical third (35.1% and 44.0%). 14,16 However, one study found bifurcation in the apical third to be more prevalent (56.9%), followed by the middle third (40%). 15 These studies described bifurcation in the coronal third as the rarest.…”

Multiple Roots and Canals in Mandibular Canines and Premolars in a Brazilian Population: A Cross Sectional Study Using CBCT and Panoramic Radiography

“…Conversely, the anterior teeth have little to none numerical variability of the roots, in most cases singlerooted teeth. However, the mandibular canine is the major exception to the rule, as shown by reports of bifurcation from the middle or apical third, as well as only bifurcation of the root canal also from the middle or apical third [3]. The bifurcation of the mandibular canines generally forms a vestibular root and a lingual root/canal.…”