Abstract
BACKGROUND: As the complex anatomy of maxillary first molars is one of the major challenges in endodontic therapy, knowledge of the complicated root canal anatomy and configuration is crucial to ensure the success of endodontic treatment and prognosis. This article presents an endodontically managed left maxillary first molar with an unusual palatal root morphology. The available literature on the anatomic variation of maxillary first molars is also reviewed. CASE SUMMARY: A 36-year-old man with no medical history presented to the Stomatology Department of Peking University Third Hospital complaining of a toothache during mastication in the maxillary left posterior region for approximately 3 mo. He had a spontaneous and intermittent toothache that had worsened, particularly at night. The diagnosis based on clinical examination, X-ray imaging, and cone beam computed tomography (CBCT) was symptomatic irreversible pulpitis. Nonsurgical endodontic therapy was performed for the left maxillary first molar. Five root canals revealed by CBCT included a special palatal root canal (1-2-1-shaped), two mesiobuccal root canals, and one distobuccal root canal. Evaluation of the CBCT images confirmed the root canal morphology and the clinician performed more effective cleaning, obturation, and therapy. Finally, the tooth was restored using composite resin, and the patient was satisfied with the result. CONCLUSION: CBCT and a complete review of the literature may be beneficial for investigating the root canal system to achieve a biological and functional therapeutic effect.