Clinical management of severe molar-incisor hypomineralisation using CAD/CAM fabricated PMMA crowns: a case report.

Background: Molar-incisor hypomineralisation (MIH) is a well-documented developmental enamel disorder, typically involving first permanent molars (FPMs) and incisors. However, atypical presentations with extensive involvement of other permanent teeth remain uncommon and poorly understood leading to management challenges. Materials and methods: This case report describes a severe presentation of MIH in a 10-year-old male, with a significant medical history of high-grade fever and febrile seizures during infancy. The patient reported normal timing of permanent tooth eruption, followed by progressive post-eruptive breakdown, affecting all permanent teeth except the premolars and second permanent molars. Clinical and radiographic evaluations confirmed severe MIH with substantial loss of enamel structure, especially in FPMs and incisors, which led to severe aesthetic and functional concerns. A comprehensive treatment plan was devised. CAD/CAM technology was employed to fabricate and deliver polymethyl methacrylate (PMMA)-based crowns for the affected teeth to restore aesthetics and function. Discussion: The patient was monitored over 24 months, demonstrating satisfactory outcomes of PMMA crowns in terms of durability, mastication, appearance and psychological benefit, indicating a successful restorative outcome. This case highlights the severe presentation of MIH, possibly linked to early childhood systemic illnesses, and individualised management of MIH, particularly in young paediatric patients.