Root-like apical hard-tissue structure associated with apical periodontitis in an immature permanent tooth: a case report and literature review

BACKGROUND: Normal root formation depends on the developing apical complex (DAC), which coordinates root and periodontal tissue development. Root-like apical hard-tissue development is a rare odontogenic finding that has been reported in association with developmental disturbances, trauma, and inflammatory conditions. CASE PRESENTATION: This case report describes a 15-year-old male presented with pain in the lower right premolar (tooth 45). Cone-beam computed tomography and histopathological revealed chronic periapical periodontitis associated with a root-like apical hard-tissue structure containing a central radiolucent canal-like space. The lesion was managed with root canal therapy and endodontic microsurgery, resulting in a favorable outcome without complications during the 12-month follow-up period. CONCLUSIONS: This case illustrates a rare root-like apical hard-tissue structure associated with chronic apical inflammation. Although the radiographic and histopathological findings were compatible with previously reported cases of segmental root development, the exact developmental origin of the lesion could not be determined. The findings contribute to the clinical characterization of a rare root-like apical hard-tissue anomalies and emphasize the importance of careful radiographic and histopathological evaluation. Combined root canal therapy and endodontic microsurgery resulted in a favourable clinical outcome in this case.