Abstract
This case report introduces the rare anatomical variation in a maxillary lateral incisor, known as the buccomesial groove (BMG). The BMG is rare and leads to endodontic-periodontal lesions. Due to its subtle presence, funnel-shaped form, and varying depth in the root, it facilitates microbial film adhesion, leading to pathology. A 25-year-old Asian male patient presented with pain in his maxillary left lateral incisor. After comprehensive clinical and radiographic assessments, the diagnosis of pulpal necrosis with symptomatic apical periodontitis associated with BMG in the maxillary left lateral incisor was confirmed. A cone-beam computed tomography preoperatively showed the groove extending from two-thirds of the buccal to the mesial side of the left lateral incisor. This case presents a new anatomical anomaly, highlighting the necessity for precise diagnosis and treatment.