Distribution and Putative Associations of Molar Incisor/Molar Hypomineralisation

The prevalence of molar incisor hypomineralisation (MIH) and molar hypomineralisation (MH) in first permanent molars appears to be increasing and management is of increasing clinical significance. Objectives: To conduct a record audit of paediatric dental patients with MIH/MH and to examine their pertinent histories. Methods: Children with hypomineralised first permanent molar(s) (n=416) were identified from a paediatric dental practice and questionnaires addressing histories were sent out; 193 were returned (46%). Data from 182 useable questionnaires and dental records were reviewed. Results: Dentitions were affected with MIH (n=104, 57%) or MH (n=78, 43%). Distribution of dentitions with MIH/MH-affected molars was: 1 molar: 38%; 2 molars: 21%; 3 molars: 13%; 4 molars: 28%. Average number of affected molars per dentition was: MIH: 2.6; MH: 1.9; MIH/MH: 2.3. Proportion of molars affected to moderate/severe degree was: MIH: 90%; MH: 82%. Distribution of 421 affected molars studied was: 16: 25%; 26: 25%; 36: 25%; 46: 25%. A total of 169 children (93%) had one or more putative factors considered (in recent literature) to predispose MIH/MH. Perinatal histories of children with MIH/MH were: birth complications: 30%; family history of “enamel defects”: 25%; prematurity: 21%; infection/illness during pregnancy: 20%. Medical histories before age 3 yrs of affected children included one or more of: fever (before 1 yr): 57%; ear infection: 53%; chicken pox: 34%; tonsillitis: 21%; allergies: 12%; asthma: 10%; other illnesses: 33%; antibiotic use: 68%. The difference between medical and perinatal histories of children in MIH and MH groups did not differ significantly (p > 0.05). Conclusions: Distributions of affected molars did not differ between quadrants or arches. A putative association was noted between MIH/MH in 1, 2, 3, or 4 affected molars and histories of fever, ear infection, or antibiotic usage before age 3 years. (Support: ADRF; GC Asia).