Thomas L Kwun, Kuan Wei Tung, Bruno Cavalcanti, Young Bin Bok, Jae Min Shin, Neville J McDonald
Accessory canals are not rare anatomical structures in maxillary central and lateral incisors. Within the limitations of this study, maxillary central and lateral incisors had 80% of accessory canals within 5.57mm and 4.27mm of the root apex. Both groups had 80% of apical delta within 2.0 mm from the root apex. Clinicians should be aware of these anatomical findings when treating maxillary incisors, particularly during endodontic microsurgery.
AIM: To evaluate the location (distance from the apex) and prevalence of accessory canals and apical delta in maxillary central and lateral incisors.
METHODS: Total of 465 maxillary incisors were collected (Central Incisor n = 230, Lateral incisor n=235). Following exclusion of inadequate teeth according to exclusion criteria, maxillary central incisors (n = 192) and lateral incisors (n = 174) were scanned using a Scanco μCT 100 Cabinet micro-CT scanner (Wangen-Brüttisellen, Switzerland). DragonFly Software (Montreal, Canada) was used to reconstruct and measure a 3-dimensional image. The measurements were made by two observers. All accessory canals (AC) and apical deltas were identified and the distance measured from the root apex for all identified accessory canals. Sample size was calculated using G∗Power, and data were statistically analyzed with estimates of the quantiles and bootstrap confidence intervals through SPSS (SPSS 31.0. Armonk, NY) and R software (R 4.4.0 Vienna, Austria). p-values ≤ 0.05 were considered statistically significant.
RESULTS: The prevalence of accessory canals in maxillary central and lateral incisors was 49% and 37.4%, respectively. In maxillary central incisors, 80% of accessory canals were located within 5.57 mm of the root apex, whereas in maxillary lateral incisors, 80% were found within 4.27 mm. The prevalence of apical delta was 2.6% in maxillary central incisors and 2.9% in maxillary lateral incisors. In both tooth types, 80% of apical deltas were confined to within 2.0 mm of the root apex.
CONCLUSION: Accessory canals are not rare anatomical structures in maxillary central and lateral incisors. Within the limitations of this study, maxillary central and lateral incisors had 80% of accessory canals within 5.57mm and 4.27mm of the root apex. Both groups had 80% of apical delta within 2.0 mm from the root apex. Clinicians should be aware of these anatomical findings when treating maxillary incisors, particularly during endodontic microsurgery.