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A Finite Element Approach for Locating the Center of Resistance of Maxillary Teeth
Published on: April 8, 2020
Micro-computed Tomographic Evaluation of the Location and Prevalence of Accessory Canals in Maxillary Central and
Thomas L Kwun1, Kuan Wei Tung1, Bruno Cavalcanti1
1Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, Ann Arbor, Michigan.
Aim:
To evaluate the location (distance from the apex) and prevalence of accessory canals and apical delta in maxillary central and lateral incisors.
Methods:
A total of 465 maxillary incisors were collected (central incisor n = 230, lateral incisor n = 235). Following the 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-computed tomography scanner (Wangen-Brüttisellen, Switzerland). DragonFly Software (Montreal, Canada) was used to reconstruct and measure a 3-dimensional image. The measurements were made by 2 observers. All accessory canals (ACs) and apical deltas were identified, and the distance was measured from the root apex for all identified accessory canals. The 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 ≤.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 ACs 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:
ACs 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 ACs within 5.57 and 4.27mm of the root apex. Both groups had 80% of the 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.