Dens Invaginatus with Apical Periodontitis: A Case Series Illustrating Oehlers Classification-based Management and Genetic Insights.

Dens invaginatus (DI), a developmental anomaly characterized by enamel organ invagination into the dental papilla, presents significant therapeutic challenges due to its complex anatomy. The treatment of DI necessitates a comprehensive assessment of multiple factors, including invagination depth, periodontal status, and the severity of pulp-periapical disease. This case series integrates clinical management with genetic analysis to explore personalized strategies for DI with apical periodontitis. Three cases were managed according to Oehlers' classification. Case 1, a tooth with type IIIa DI with peri-invagination periodontitis received endodontic treatment of the invagination and successfully preserved pulp vitality of the true canal, resulting in sustained periapical bone healing improvement over 24 months. Case 2 and 3, two teeth with type II DI were treated with conventional nonsurgical root canal treatment, one of which subsequently required apical surgery. Both achieved complete periapical lesion healing at 12-month follow-up. Concurrently, whole-genome shotgun sequencing of a familial cohort presenting with concomitant DI and microdontia identified putatively relevant variants in several genes, with a notable variant in BCL11B, a gene associated with isolated microdontia. Additional variants in ANKRD26, NOTCH3, and PAX3 suggest a potential oligogenic contribution to this developmental anomaly. This case series provides a pragmatic clinical perspective for conservative, vital pulp therapy in select DI cases and offers preliminary genetic insights.