Clinical and Radiographic Evaluation of Molar Root-Incisor Malformation (MRIM): A Case Series

Molar root-incisor malformation (MRIM) is a rare dental anomaly characterized by root malformations, abnormal pulp chamber development, and dental developmental defects. Primarily affecting the permanent first molars, MRIM can also involve the primary second molars and permanent maxillary central incisors. The etiology of MRIM remains unclear, though it has been associated with environmental and systemic factors. Early diagnosis and intervention are essential for preventing further complications.

This report presents five pediatric cases diagnosed with MRIM at our pediatric dentistry clinic between 2016 and 2025. Case 1: A 10-year-old male patient presented for a routine examination. MRIM was detected in Teeth 16, 26, and 36, with enamel depressions on Teeth 11 and 21. No systemic disease or family history of dental anomalies was noted. Case 2: An 8-year-old female patient presented with esthetic concerns due to dental crowding. MRIM affected multiple teeth (16, 26, 36, 46, 13, 23, 11, 21, 31, and 41). The patient had a history of pelvicaliectasis and nephrological follow-up. Case 3: A 12-year-old female patient was referred due to suspected root anomalies. MRIM was observed in all permanent teeth except anterior incisors and third molars. A history of hemolytic uremic syndrome was noted. Case 4: An 11-year-old male patient presented with MRIM involving molars and canines. A neonatal history of severe hypertension and NICU admission was reported. No familial dental anomalies were found. Case 5: A 9-year-old female patient diagnosed with Williams syndrome and other systemic conditions exhibited MRIM in multiple teeth. Structural anomalies such as high-arched palate, ankyloglossia, and deep bite were also observed.

The cases demonstrate the variability of MRIM in pediatric patients, with distinct radiographic and clinical features observed across the cohort. The absence of similar findings in family members suggests that a direct genetic basis is unlikely. Instead, the findings support a possible association between MRIM and systemic conditions, particularly nephrological diseases and complex medical histories. Early and accurate diagnosis, along with close follow-up, is vital in managing MRIM and preventing future complications. A comprehensive medical history and thorough radiographic evaluation of all tooth groups remain essential for accurate diagnosis and treatment planning.