Distribution and severity of molar hypomineralisation: trial of a new severity index

Int J Paediatr Dent. 2014 Mar;24(2):131-51. doi: 10.1111/ipd.12040. Epub 2013 May 22.


Background: Current molar hypomineralisation (MH) indices do not guide clinicians in management of affected dentitions, and treatment is based on individual judgment.

Aim: The aims of this study were to describe characteristics of MH and molar incisor hypomineralisation (MIH) and trial the new Molar Hypomineralisation Severity Index (MHSI).

Design: First permanent molars (FPMs) and permanent incisors (PIs) in 283 affected children were examined for hypomineralisation characteristics [defect colour, location, post-eruptive breakdown (PEB); restorations placed/replaced/atypical; sensitivity]. The MHSI scores were compared with treatment received (152 children).

Results: Mean (SD) affected teeth/dentition were as follows: FPMs: 3.2 (1.0) and PIs: 1.6 (1.6). Affected FPMs showed no arch or quadrant predilection; maxillary central PIs were affected particularly. As affected FPMs/dentition increased, MIH diagnoses also increased (P = 0.009). Among FPMs, defects most prevalent were brown (47%) and cuspal (74%); 67% showed PEB. Before study entry, 43% of FPMs had restorations placed/replaced. Among PIs, white defects were common (65%) on smooth surfaces; sensitivity was rare. Affected FPMs received more restorations and extractions than unaffected FPMs (P = 0.0001). As MHSI scores increased, FPM treatments/dentition increased (number, invasiveness). All characteristics were significant in predicting treatment (logistic regression model).

Conclusions: A spectrum from MH to MIH occurred. The MHSI characteristics were predictive of the treatment of affected FPMs and can guide management.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dental Enamel Hypoplasia / therapy*
  • Humans
  • Severity of Illness Index