Evaluation of the Internal Anatomy of Maxillary First Molars in an Iranian Population Using Cone-Beam Computed Tomography

Background and aim: the heightened incidence of endodontic failure in maxillaryfirst molars (mfms) has been attributed to their morphological complexitiesnotably evident in the mesiobuccal (mb) root canals. given the absence of data onthe internal anatomy of mfms among the iranian population, this research aimed toevaluate the root canal system (rcs) morphology of mfms utilizing cone beamcomputed tomography (cbct).materials and methods: in this descriptive retrospective study, internal anatomyof 314 mfms was evaluated on cbct scans taken from patients attending adentomaxillofacial radiology clinic. cbct scans of mfms were retrieved andinterpreted by observers for their internal anatomy. fisher’s exact test, chi- squaretest, independent-samples t-test and one-way anova were used to analyze datausing spss 26 software.results: of a total of 314 mfms evaluated, 97.5% [95% ci: (95.7%, 99.2%)] hadthree roots and 67.2% [95% ci: (62.0%, 72.3%)] had four root canals; thedifference in number of canals was not significant between males and females(p=0.130). in 68.4% of cases, mfms on both sides exhibited morphologicalsimilarity. accessory canals were more commonly encountered in individualsbetween 40 to 60 years of age in all roots except for mb root; whereas in mb root,accessory canals were more commonly seen in 20-40 year olds. vertucci’s types ii, iand iii were the most common canal types in evaluated mb roots. vertucci’s type iwas the most common type in distobuccal (db) and palatal (p) root canals.conclusion: more than half of the mb roots of mfms had two root canals. cbctscans could give valuable anatomical information prior to endodontic treatments.some anatomical features varied according to the patient’s gender and age.