Department of Therapeutic Dentistry, Samara State Medical University, Samara, Russian Federation.
Dental Specialty Centre, Brazilian Military Police, Minas Gerais, Brazil.
Int Endod J. 2024 Sep;57(9):1371-1378. doi: 10.1111/iej.14076. Epub 2024 Apr 30.
To describe the management of the palato-mesiobuccal (PMB) canal in maxillary second molars with fused roots using conventional techniques.
Root canal treatment success hinges upon effectively addressing the intricate and variable anatomy of molar teeth. Failure to do so can lead to persistent infections and treatment failure. Recent advancements in imaging technologies have provided unparalleled insights into dental anatomy, especially in molars. Among these discoveries is the PMB canal, a unique anatomical variant recently reported for the first time in Endodontic literature. This canal, found in maxillary second molars with fused roots and originating from the coronal third of the palatal canal while traversing towards the mesiobuccal root presents challenges in clinical management due to its location. This article is the first to showcase the management of the PMB canal using conventional techniques. In the first case, a 38-year-old male patient presented with asymptomatic irreversible pulpitis in the maxillary second right molar. Following thorough instrumentation and irrigation, the presence of the PMB canal was discovered during root canal preparation. The canal was managed using rotary instruments and obturated successfully, resulting in a symptom-free tooth at an 8-year follow-up. The second case illustrates a similar scenario in a 23-year-old female patient presenting with symptomatic irreversible pulpitis in tooth 17. The PMB canal was identified during treatment and managed using rotary nickel-titanium instruments, leading to a favourable outcome at a 9-year follow-up.
In fused roots of maxillary second molars, a PMB canal might be expected. Exploration of the buccal wall of the palatal canal under magnification after shaping procedures can reveal the PMB canal orifice in fused roots. Small tapers are suggested for the enlargement of the PMB canal. Continuous bleeding spots in the palatal canal might indicate a possible PMB canal orifice in vital cases. The use of an apex locator is suggested for the differential diagnosis of the PMB canal orifice from a perforation site.
描述使用常规技术处理融合根上颌第二磨牙的近颊-中颊（PMB）根管。
根管治疗的成功取决于能否有效地解决磨牙复杂多变的解剖结构。如果处理不当，可能会导致持续感染和治疗失败。最近影像学技术的进步为牙体解剖结构提供了前所未有的深入了解，尤其是在磨牙中。其中一项发现是 PMB 根管，这是一种独特的解剖学变异，最近首次在牙髓学文献中报道。该根管存在于融合根上颌第二磨牙中，起源于腭管的冠三分之一，向近颊根方向穿行，由于其位置，在临床管理中带来了挑战。本文首次展示了使用常规技术处理 PMB 根管的方法。在第一个病例中，一位 38 岁的男性患者上颌右侧第二磨牙出现无症状不可复性牙髓炎。在彻底的器械和冲洗后，在根管预备过程中发现了 PMB 根管。该根管使用旋转器械进行处理并成功堵塞，在 8 年的随访中，该牙齿无症状。第二个病例是一位 23 岁的女性患者，上颌 17 牙出现有症状的不可复性牙髓炎。在治疗过程中发现了 PMB 根管，并使用旋转镍钛器械进行处理，在 9 年的随访中取得了良好的结果。
在融合根上颌第二磨牙中可能存在 PMB 根管。在成形术后放大下探查腭管颊侧壁可以发现融合根中的 PMB 根管口。建议使用小锥度扩大 PMB 根管。在活髓病例中，腭管持续出现出血点可能表明存在 PMB 根管口。建议使用根尖定位仪对 PMB 根管口与穿孔部位进行鉴别诊断。
