Rationale: Dens invaginatus (DI) is a rare condition with a prevalence of only 0.3% to 10% mainly affecting the maxillary lateral incisors. In the present case, we describe management of the rarest variant of DI, that is, Oehler type III DI. Patient concerns: Patient complained of severe pain in upper left front teeth since 1 month which aggravated on taking hot liquids. Patient had visited a general dentist who did emergency access opening on #9 and #10 and referred the patient. Diagnoses: Oehler type III DI with apical periodontitis w.r.t.#10 (maxillary left lateral incisor). Interventions: Nonsurgical root canal treatment of the main canal and apexification of pseudo canal with mineral trioxide aggregate. Outcomes: At 6 months follow-up, the patient was asymptomatic, and the clinical evaluation revealed no sensitivity to percussion or palpation on tooth #10 and mobility within normal limits. The radiograph examination displayed significant periapical healing. Lessons: The unusual morphological appearance of the crown in the maxillary lateral incisor or the radiographic appearance should alert the dentist to the possibility of DI. Knowledge of tooth anatomy and its variations, correct diagnosis, and use of magnification and advanced materials like mineral trioxide aggregate can help in managing rare variations.

This systematic review and meta-analysis aim to compile and critically evaluate the existing published literature evaluating the effect of surface treatmen