Preserving the Neurovascular Bundle in Targeted Endodontic Microsurgery (TEMS): A Case Series.

Abstract: Endodontic microsurgery encompasses the use of microscopy, specialized instruments and advanced imaging with cone beam computer tomography (CBCT). This treatment modality results in high clinical success rates and facilitates the enucleation of osteolytic lesions, resection of apical root canal complexities harboring persistent bacterial biofilms, and evaluation of possible root defects and fractures. However, there is the risk of injury to important anatomical structures, particularly when treating posterior teeth. Neurovascular bundles are among these structures at risk for injury. Fortunately, high resolution CBCT scans can be used to detect these structures that are known to have a high anatomical variability. In addition, CBCT information can be combined with high resolution intraoral scans to plan, design and fabricate surgical guides to be used in a targeted endodontic microsurgery (TEMS) approach. We report three cases with previous endodontic treatment having persistent apical periodontitis that were treated with TEMS to avoid damage of the neurovascular bundles at risk of injury. In the first case, the palatal root of tooth #14 was adjacent to the greater palatine artery. In the second case, the mental nerve exited through two separate foramina close to the predictive osteotomy site for the mesial root of tooth #19. In the third case, the posterior superior alveolar artery (PSAA) was in close proximity to the mesio-buccal root of tooth #14. Collectively, these cases illustrate the diagnostic value of CBCT for detecting neurovascular bundles and the use of TEMS to mitigate the risk of injury to these important structures. Thus, the combination of CBCT and TEMS can potentially minimize the risk of intraoperative complications and postoperative sequela, while increasing the predictability of endodontic microsurgeries in complex cases.