Non-Surgical Root Canal Resolves Rare Mandibular Molar Malformation in Teenager: Case Report

The case involved a 14-year-old boy who presented with pain and swelling in the lower right molar region, specifically tooth #30. Upon examination, the tooth exhibited an unusual crown shape but no visible signs of decay. Despite these atypical features, the tooth remained firm with normal periodontal probing depths. Further investigation through intraoral radiographs and cone beam computed tomography (CBCT) revealed the presence of Oehlers’ Type II Dens Invaginatus—an uncommon developmental anomaly where enamel and dentin fold into the pulp cavity—and a large radiolucent area around the root, indicative of periradicular pathology.

The patient’s medical history was also noteworthy. Born prematurely at 32 weeks, he had undergone intrauterine feto-fetal blood transfusion and had experienced both stroke and respiratory arrest at birth. Despite these early health complications, he was in good general health at the time of evaluation.

Given the complexity of the case, a conservative, non-surgical approach was selected. Root canal therapy was carried out with precision to thoroughly clean and disinfect the canal system, which is often complicated in teeth affected by DI due to their highly variable internal anatomy. The root canal system was subsequently sealed with a biocompatible filling material, ensuring long-term integrity.

The patient was monitored for 46 months. Throughout this follow-up, he remained asymptomatic, with no pain or sensitivity, and the treated tooth remained stable and functional. Most significantly, radiographic examinations confirmed progressive and ultimately complete healing of the periapical tissues.

The authors emphasized that, to their knowledge, very few cases of DI in mandibular molars have been conservatively managed with guidance from CBCT imaging. This report not only showcases a successful treatment outcome but also underscores the critical role of advanced imaging tools in diagnosing and planning treatment for complex dental anomalies. CBCT allowed for precise visualization of the abnormal anatomy, which contributed to the tailored, effective treatment strategy.

The authors conclude, "The case contributes to the limited body of literature on non-surgical treatment of Dens Invaginatus in lower molars, demonstrating that even challenging anatomical cases can be managed effectively with modern endodontic techniques and technology."

Reference:

Cantarini, J. M., Sans, F. A., Abbott, P. V., & Garcia-Font, M. (2025). Non-surgical endodontic treatment of an atypical mandibular first molar with a Dens Invaginatus and a large periradicular radiolucency – A case Report. Journal of Endodontics. https://doi.org/10.1016/j.joen.2025.05.023