Maksiller Molar Dişlerde İkinci Mesiobukkal Kanalın Saptanması İçin Klinik Bir Çerçeve

Abstract

Maksiller molar dişler, karmaşık kök kanalı morfolojileri nedeniyle endodontik açıdan önemli zorluklar sunar. Literatür, bu dişlerin mesiobukkal (MB) köklerinde ikinci bir kanal (MB2) görülme sıklığının %90’lar kadar yüksek olabileceğini gösterse de, klinik ortamda bu kanalın saptanma oranları genellikle daha düşüktür. MB2 kök kanalının tedavi edilmeden bırakılması, kök kanal sistemi içinde mikroorganizmaların ve ölü dokuların kalmasına neden olur. Bu durum sıklıkla periapikal lezyonlarla sonuçlanır veya mevcut enfeksiyonların iyileşmesini engelleyerek tedavinin başarısız olmasındaki temel nedenlerden birini oluşturur. Bu derleme, klinisyenlerin MB2 kanalını saptama ve güvenli bir şekilde yönetme konusundaki yeterliliklerini artırmak amacıyla güncel tanı kriterlerini ve klinik metodolojileri ana hatlarıyla sunmaktadır. Çalışma; konik ışınlı bilgisayarlı tomografinin tanısal faydasını ortaya koymakta, dental mikroskoplar ve büyütme cihazlarının sağladığı gelişmiş görselleştirmeyi vurgulamakta, ultrasonik uçlar kullanılarak uygulanan güvenli oluk aşındırma yöntemlerini özetlemekte ve doğru kök kanalı lokalizasyonu için gerekli olan anatomik prensipleri tartışmaktadır. Ayrıca, MB1 ve palatal kanallar arasındaki mekânsal ilişki ile hizalanma dahil olmak üzere morfometrik ölçümlerin klinik önemi değerlendirilmektedir. MB2 kanalının saptanması, hem teknolojiye hem de hekimin anatomi ve klinik protokoller konusundaki uzmanlığına dayanmaktadır. Bu derlemede çerçevesi çizilen klinik yaklaşım, özellikle kalsifiye veya dar kök kanallarının yönetimi konusunda klinisyenlere rehberlik ederek endodontik sonuçları iyileştirmek için tasarlanmıştır.

Keywords

• Maksiller molar
• MB2 kanalı
• MB2 kanal tanımlama
• Kök kanal morfolojisi
• Ultrasonik aşındırma

A Clinical Framework for the Detection of the Second Mesiobuccal Canal in Maxillary Molars

Abstract

Maxillary molars present significant endodontic challenges owing to their intricate root canal morphology. While the literature indicates that the occurrence of a second canal (MB2) in the mesiobuccal (MB) roots of these teeth may be as high as 90%, clinical detection rates for this canal are typically lower. If the MB2 root canal is left untreated, microorganisms and dead tissue can remain in the root canal system. This often results in periapical lesions or prevents existing infections from healing, making it a major cause of failure. This narrative review outlines contemporary diagnostic criteria and clinical methodologies designed to enhance clinicians’ proficiency in the detection and safe management of the MB2 canal. This study presents the diagnostic utility of cone-beam computed tomography, highlights the enhanced visualization afforded by dental microscopes and magnification devices, outlines safe troughing methods utilizing ultrasonic tips, and discusses anatomical principles essential for accurate root canal localization. Furthermore, the clinical significance of morphometric measurements, including the spatial relationship and alignment between the MB1 and palatal canals, is evaluated. Detecting the MB2 canal relies on both technology and the clinician's expertise with anatomy and clinical protocols. The clinical framework outlined in this review is designed to enhance endodontic outcomes by providing clinicians with guidance, especially regarding the management of calcified or narrow root canals.

Keywords

• Maxillary molar
• MB2 canal
• MB2 canal identification
• Root canal morphology
• Ultrasonic troughing

References

1. Haug SR, Røegh M, Fristad I. Endodontic emergency patients’ profile and treatment outcome - a prospective cohort study. BMC Oral Health. 2024; 24: 1557. doi: 10.1186/s12903-024-05338-8
2. Aydın H. Relationship between crown and root canal anatomy of four-rooted maxillary molar teeth. Aust Endod J. 2021; 47: 298-306. doi: 10.1111/aej.12478
3. Aydın H. Correlations between additional roots in maxillary second molars, maxillary first premolars, mandibular first molars and mandibular first premolars: a retrospective cone-beam computed tomography analysis. Odontology. 2022; 110: 585-95. doi: 10.1007/s10266-022-00687-8
4. Hiebert BM, Abramovitch K, Rice D, et al. Prevalence of second mesiobuccal canals in maxillary first molars detected using cone-beam computed tomography, direct occlusal access, and coronal plane grinding. J Endod. 2017; 43: 1711-5. doi: 10.1016/j.joen.2017.05.011
5. Farrash HS, Alsofi L, Balto K. Impact of visual magnification on MB2 canal detection in a laboratory-based study using standardized 3D-printed maxillary molars. Appl Sci. 2026; 16: 493. doi: 10.3390/app16010493
6. Camacho-Aparicio LA, Borges-Yáñez SA, Estrada D, et al. Validity of the dental operating microscope and selective dentin removal with ultrasonic tips for locating the second mesiobuccal canal (MB2) in maxillary first molars: an in vivo study. J Clin Exp Dent. 2022;14(6):e471–8. doi:10.4317/jced.59347
7. Ertürk İD, Keleş A, Keskin C. Effect of troughing on the identification of the second mesiobuccal canals with and without calcifications in maxillary first molars. Aust Endod J. 2025;51(1):150–4. doi:10.1111/aej.12922
8. Ozemre MO, Karslıoglu H, Kamburoglu K. An evaluation of the relationship between the mesiobuccal canal configuration, the interorifice distance, and the root lengths of the permanent maxillary first molars with cone beam computed tomography. Diagnostics. 2024;14(23):2703. doi:10.3390/diagnostics14232703

9. Wu JY, Chiang HS, Chen YJ, et al. Prevalence of second mesiobuccal canal in maxillary first and second molar detected using cone-beam computed tomography in the Han population: A systemic review and meta-analysis. J Dent Sci. 2026;21(1):333–40. doi:10.1016/j.jds.2025.09.008
10. Aydın H. Analysis of root and canal morphology of fused and separate rooted maxillary molar teeth in Turkish population. Niger J Clin Pract. 2021;24(3):435–42. doi:10.4103/njcp.njcp_316_20
11. Moidu NP, Sharma S, Kumar V, et al. Association between the mesiobuccal canal configuration, interorifice distance, and the corresponding root length of permanent maxillary first molar tooth: a cone-beam computed tomographic study. J Endod. 2021;47(1):39–43. doi:10.1016/j.joen.2020.08.025
12. Martins JNR, Martins JNR, Ensinas P, et al. The global periapical health study: a big data CBCT analysis of periapical pathology across 54 countries. J Endod. 2026;52(5):740-60. doi:10.1016/j.joen.2026.01.021
13. Zargar N, Khosravi K, Zadsirjan S, et al. The association of endodontic prognostic factors with the presence of periapical lesion, its volume, and bone characteristics in endodontically treated molars: a cross-sectional study. BMC Oral Health. 2024;24(1):28. doi:10.1186/s12903-023-03818-x
14. Keskin NB, Tezer EO, Uslu G, et al. Evaluation of failed endodontically treated molar teeth using micro-computed tomography. BMC Oral Health. 2025;26(1):246. doi:10.1186/s12903-025-07301-7
15. León-López M, Montero-Miralles P, Cabanillas-Balsera D, et al. Association between the presence of missed canals, detected using CBCT, and post-treatment apical periodontitis in root-filled teeth: a systematic review and meta-analysis. J Clin Med. 2025;14(16):5781. doi:10.3390/jcm14165781
16. Fuentes BYB, Monsalve JOM, Herrera UM, et al. Apical periodontitis in endodontically-treated teeth: association between missed canals and quality of endodontic treatment in a Colombian sub-population. A cross-sectional study. Acta Odontol Latinoam. 2024;37(1):59–67. doi:10.54589/aol.37/1/59
17. Plotino G, Grande NM. Detection of canal orifices, negotiation, and management of calcified and curved canals. In: Endodontic Advances and Evidence-Based Clinical Guidelines. John Wiley and Sons Ltd; 2022. p. 393–439. doi:10.1002/9781119553939.ch17
18. Zhang Y, Xu H, Wang D, et al. Assessment of the second mesiobuccal root canal in maxillary first molars: a cone-beam computed tomographic study. J Endod. 2017;43(12):1990–6. doi:10.1016/j.joen.2017.06.021
19. Su CC, Wu YC, Chung MP, et al. Geometric features of second mesiobuccal canal in permanent maxillary first molars: a cone-beam computed tomography study. J Dent Sci. 2017;12(3):241–8. doi:10.1016/j.jds.2017.03.002
20. Normando PHC, Dos Santos JCM, Akisue E, et al. Location of the second mesiobuccal canal of maxillary molars in a Brazilian subpopulation: analyzing using cone-beam computed tomography. J Cont Dent Prac. 2022;23(10):979–83. doi:10.5005/jp-journals-10024-3422
21. Rosado LPL, Freitas DQ, Rovaris K, et al. Can maxillary molar dimensions predict the presence of the second mesiobuccal canal? Oral Radiol. 2023;39(3):482–90. doi:10.1007/s11282-022-00661-8
22. Perondi I, Taschieri S, Baruffaldi M, et al. The Correlation between intraorifice distance and the anatomical characteristics of the second mesiobuccal canal of maxillary molars: A CBCT Study. Int J Dent. 2024;2024:6636637. doi:10.1155/2024/6636637
23. de Freitas JV, Baratto-Filho F, Coelho BS, et al. Efficacy of different cone-beam computed tomographic protocols in the identification of mesiobuccal canals of maxillary first molars: a tomographic and ex vivo study. J Endod. 2017;43(5):810–5. doi: 10.1016/j.joen.2016.12.011
24. Tonelli SQ, Sousa-Neto MD, Leoni GB, et al. Micro-CT evaluation of maxillary first molars: interorifice distances and internal anatomy of the mesiobuccal root. Braz Oral Res. 2021; 35: 1–8. doi: 10.1590/1807-3107BOR-2021.VOL35.0060
25. Wang M, Gao Y, Deng Q, et al. Assessment of the coronal root canal morphology of permanent maxillary first molars using digital 3D-reconstruction technology based on micro-computed tomography data. J Dent Sci. 2023;18(2):586–93. doi: 10.1016/j.jds.2022.08.011
26. Shen Y, Gu Y. Assessment of the presence of a second mesiobuccal canal in maxillary first molars according to the location of the main mesiobuccal canal-a micro-computed tomographic study. Clin Oral Investig. 2021;25(6):3937-44. doi: 10.1007/s00784-020-03723-5
27. Rosado LPL, Freitas DQ, Rovaris K, et al. Can the detection of second mesiobuccal canals be enhanced based on the volume of adjacent canals? Arch Oral Biol. 2023;146:105604. doi: 10.1016/j.archoralbio.2022.105604
28. Aqili TM, Alharbi SO, Almuzaini SN, et al. The correlation between crown size and presence of MB2 in first and second permanent maxillary molars using cone-beam computed tomography endodontics and conservative section. Ain Shams Dental Journal 2024;35(3):426-32. doi: 0.21608/asdj.2024.294011.1305
29. Martins JNR, Alkhawas MBAM, Altaki Z, et al. Worldwide analyses of maxillary first molar second mesiobuccal prevalence: a multicenter cone-beam computed tomographic study. J Endod. 2018;44(11):1641-9. doi: 10.1016/j.joen.2018.07.027
30. Verma P, Love RM. A Micro CT study of the mesiobuccal root canal morphology of the maxillary first molar tooth. Int Endod J. 2011;44(3):210–7. doi:10.1111/j.1365-2591.2010.01800.x
31. Chan Shu Wen K, Wee LC, Wei M, et al. 2D versus 3D radiographic assessment of asymptomatic persistent endodontic lesions. Int Endod J. 2025;58(10):1551–64. doi: 10.1111/iej.14272
32. Tchorz JP, Konstantiniuk N, Sistig JJA, et al. Ideal horizontal X-Ray beam angulation for maxillary molars. A retrospective clinical study using cone-beam computed tomography. Aust Endod J. 2025;51(3):584–8. doi: 10.1111/aej.12970
33. Aydın H, Mobaraki S. Comparison of root and canal anatomy of taurodont and normal molar teeth: A retrospective cone-beam computed tomography study. Arch Oral Biol. 2021; 130: 105242. doi: 10.1016/j.archoralbio.2021.105242
34. Mohammad-Rahimi H, Ourang SAH, Nosrat A, et al. Effect of voxel size on cone-beam computed tomography-based assessment of root canal anatomy: a systematic review and meta-analysis. Int Endod J. 2026; 59(4): 574-89. doi: 10.1111/iej.70092
35. Parirokh M, Manochehrifar H, Kakooei S, et al. Variables that affect the ability to find the second mesiobuccal root canals in maxillary molars. Iran Endod J. 2023;18(4):248–53. doi: 10.22037/iej.v18i4.42260
36. McGuigan MB, Duncan HF, Krastl G, et al. The impact of cone beam CT on outcomes associated with endodontic access cavity preparation: a controlled human analogue study using 3D-printed first maxillary molars. Dentomaxillofac Radiol. 2025; 54(1): 43–55. doi: 10.1093/dmfr/twae048
37. Parker J, Mol A, Rivera EM, et al. CBCT uses in clinical endodontics: the effect of CBCT on the ability to locate MB2 canals in maxillary molars. Int Endod J. 2017;50(12):1109–15. doi: 10.1111/iej.12736
38. Alencar-Palha C, da Silva Morais MN, Fagundes FB, et al. Role of tube current variation and metal artifact reduction tool in CBCT for detection of missing MB2 canal. Braz Dent J. 2025;36:e236491. doi: 10.1590/0103-644020256491
39. Aminsobhani M, Majidi S. Clinical significance of mesiobuccal and distobuccal canal variations in maxillary molars: a case series and a mini review. Case Rep Dent. 2025; 2025(1): 5581317. doi: 10.1155/crid/5581317
40. Coelho MS, Lacerda MFLS, Silva MHC, et al. Locating the second mesiobuccal canal in maxillary molars: Challenges and solutions. Clin Cosmet Invest Dent. 2018; 20(10); 195–202. doi: 10.2147/CCIDE.S154641
41. Keleş A, Keskin C, Versiani MA. Micro-CT assessment of radicular pulp calcifications in extracted maxillary first molar teeth. Clin Oral Investig. 2022; 26(2): 1353–60. doi: 10.1007/s00784-021-04109-x
42. de Oliveira HF, Gobbi BR, Vaz AS, et al. Impact of multiple individualized guides on the management of obliterated root canals in a maxillary first molar: a case report. Eur Endod J. 2025; 10(5): 441–6. doi: 10.14744/eej.2025.80775
43. Santos-Junior AO, Fontenele RC, Tavares KIMC, et al. Effectiveness and safety of three NiTi systems in endodontic retreatment of MB1 and MB2 root canals: a micro-CT and CBCT combined analysis. Clin Oral Investig. 2025; 29(4): 194. doi: 10.1007/s00784-025-06273-w
44. Ensinas P, de la Casa ML. Effect of mechanized instrumentation on distal wall thickness of the second mesiobuccal canal. Acta Odontol Latinoam. 2025; 38(2): 170–8. doi: 10.54589/aol.38/2/170
45. Keleş A, Keskin C, Çiftçioğlu E, et al. Evaluation of the band-shaped isthmuses in the mesiobuccal root canal system using micro-computed tomography. Clin Oral Investig. 2022; 26(9): 5909–14. doi: 10.1007/s00784-022-04548-0