What is the best way to find mb2 canal in first maxillary molars?

Discussion

The geometrical location of the MB2 canal has only been reported using in vitro studies [7, 22–24], however, a previous study by our group in second maxillary molars [14] demonstrated the efficiency of CBCT on MB2 canal location in vivo. This article is intended to expand the study sample used by Betancourt et al. [14], increasing the sample of 225 to 1,100 maxillary molars, also the study of the first maxillary molars were included. We observed that the MB2 canal was located in the 1MM 2.68 ± 0.49 mm palatally and 1.25 ± 0.34 mesially to the MB1 canal. In the 2MM it was located 2.41 ± 0.64 mm palatally and 0.98 ± 0.33 mm mesially, whereas Betancourt et al. [14], using the same technique, found it to be 2.2 ± 0.54 mm palatally and 0.98 ± 0.32 mesially to the MB1 canal. Gorduysus et al. [22] reported the MB2 location 1.65 ± 0.72 mm palatally and 0.69 ± 0.42 mesially to the MB1 canal in a combined study of first and second molars.

Prevalence and location of the secondary mesiobuccal canal in 1,100 maxillary molars using cone beam computed tomography. © The Author(s). 2016. Creative Commons Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/).

Introduction

Missed MB2 canals are recognized as a leading cause of endodontic failure in maxillary molars, as untreated canal spaces may harbor bacterial biofilms that contribute to persistent periapical pathology and reinfection [12,13]. Therefore, accurate localization of this canal is essential for achieving long-term success in root canal therapy. To improve canal detection and reduce the risk of missed anatomy, clinicians are encouraged to use enhanced visualization and diagnostic aids beyond conventional direct visual methods (DVMs) [14]. In addition to anatomical complexity, pulp calcification and secondary dentin deposition may further obscure the pulpal floor anatomy, particularly in narrow or curved MB2 canals, thereby complicating canal orifice identification. To overcome these limitations, ultrasonic troughing has been proposed as a minimally invasive technique involving selective dentin removal along the pulpal floor to facilitate access to calcified or hidden canal orifices. When performed in a controlled manner, troughing may improve canal visibility while preserving tooth structure [15].

Diagnostic Performance of Magnification and Ultrasonic Troughing in Detecting Second Mesiobuccal Canals: A Two-Factor Experimental Study. Copyright © 2026, Adiguzel et al. Creative Commons Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/).

Abstract

The purpose of this study was to determine if the surgical operating microscope and/or dental loupes could enhance the practitioner's ability to locate the second mesiobuccal canal (MB2) canal of maxillary molars in an in vivo, clinical setting. The participating endodontists documented 312 cases of root canal therapy on maxillary first and second molars. Participants that used the microscope or dental loupes located the MB2 canal with a frequency of 57.4% and 55.3%, respectively. Those using no magnification located the MB2 canal with a frequency of 18.2%. When no magnification was used, significantly fewer MB2 canals were located based by Chi-square analysis at p < 0.01. There was no significant difference between the use of the microscope and dental loupes in the frequency of locating the MB2 canal. When the maxillary first molars were considered separately, the frequency of MB2 canal detection for the microscope, dental loupes, and no magnification groups was 71.1%, 62.5%, and 17.2%, respectively. The results of this study show that the use of magnification in combined groups leads to a MB2 detection rate approximately three times that of the nonmagnification group and that the use of no magnification results in the location of significantly fewer MB2 canals. Based on these results, more emphasis should be placed on the importance of using magnification for locating the MB2 canal.

Abstract

OBJECTIVES: The present study aimed to evaluate the frequency, position, and length of radicular pulp calcifications in three-rooted maxillary first molars using micro-computed tomography. MATERIALS AND METHODS: Two hundred three-rooted maxillary first molars were scanned at a pixel size of 10&#xa0;&#xb5;m and reconstructed using similar parameters. Three-dimensional models of the mesiobuccal (MB1, MB2, MB3), distobuccal (DB), and palatal (P) canals were qualitatively evaluated for discontinuity in the canal path. Transaxial and sagittal cross-sectional images of the roots were further screened, and the complete obliteration of the canal lumen by pulp calcification was identified when the canal had similar radiodensity to the surrounding dentine. Then, the number, position, and length of the calcifications were recorded for each root. Intra-observer agreement was performed using Cohen's kappa test, while one-way ANOVA and Duncan tests compared the lengths of calcifications among the canals, with &#x3b1;&#x2009;=&#x2009;5%. RESULTS: Intra-observer agreement was perfect for identification of pulp calcifications (&#x138;&#x2009;=&#x2009;1.0; p&#x2009;=&#x2009;0.000). MB2 and MB3 canals accounted for the highest percentage frequency of calcifications distributed throughout the canal path. In the MB1, DB, and P canals, they occurred mainly at the apical third. Lengths of calcifications were greater in the MB3 (0.89&#x2009;&#xb1;&#x2009;0.81&#xa0;mm) and MB2 (0.82&#x2009;&#xb1;&#x2009;0.93&#xa0;mm) canals than in the MB1 (0.39&#x2009;&#xb1;&#x2009;0.32&#xa0;mm), DB (0.34&#x2009;&#xb1;&#x2009;0.22&#xa0;mm), and P (0.28&#x2009;&#xb1;&#x2009;0.22&#xa0;mm) canals (p&#x2009;<&#x2009;0.05). CONCLUSION: MB2 and MB3 canals accounted for the highest frequency and length of radicular pulp calcifications. In the MB1, DB, and P canals, calcifications occurred mostly at the apical third, while in the MB2 and MB3, most of calcifications were observed at the orifice level and along the canal path. CLINICAL RELEVANCE: In maxillary first molars, radicular pulp calcifications are mainly located at the apical third of the MB1, DB, and P canals, while in the MB2 and MB3 canals, most of them are at the orifice level or along the canal path.

Abstract

Maxillary molars are prone to endodontic failure due to complex mesio-buccal canal anatomy. With increasing use of cone-beam computed tomography (CBCT), clinicians often have access to scans of homologous or contralateral teeth. This study assessed whether CBCT could predict the presence and configuration of the second mesio-buccal canal (MB2) based on bilateral symmetry. Ninety-nine CBCT scans of bilateral first and second maxillary molars were analysed. MB2 prevalence and Vertucci classification were compared among homologous, adjacent, and contralateral molars. MB2 canals were present in 96.5% of first and 81.3% of second molars. Strong correlations were found between bilateral first molars (91.9%) and bilateral second molars (78.8%), whereas agreement between adjacent or contralateral molars was lower (~60%, p&#x2009;<&#x2009;0.05). These results indicate that CBCT scans can reliably predict the presence and configuration of the MB2 canal in bilateral maxillary molars, but this correlation does not extend to adjacent or contralateral teeth.