Decompression of a Dentigerous Cyst in a Child With Molar-Incisor Hypomineralization: A Seven-Year Follow-Up Case Report

Dentigerous cysts are common developmental odontogenic cysts that may compromise the eruption and morphology of developing teeth. Their management of children increasingly favors conservative approaches, particularly when tooth preservation is possible. Molar-incisor hypomineralization (MIH) introduces additional clinical considerations due to enamel fragility, which may affect patient comfort and complicate postoperative hygiene. An eight-year-old boy with MIH presented with a dentigerous cyst associated with the unerupted mandibular right second molar (tooth 47), incidentally identified on a panoramic radiograph. Cone-beam computed tomography confirmed a well-defined unilocular cyst enveloping the crown of the tooth. Decompression was performed to preserve the developing tooth. Progressive radiographic improvement was observed over the following months, with gradual repositioning and eruption of the tooth into functional occlusion despite altered root development. No recurrence was detected during a seven-year follow-up. Management of MIH-related fragility included fluoride application, enhanced oral hygiene, and restorative treatment. This case highlights the feasibility of tooth preservation despite altered root development and MIH-related enamel fragility. Early diagnosis, detailed imaging, and structured follow-up are essential for achieving favorable outcomes.