Molar incisor hypomineralisation (MIH) training manual for clinical field surveys and practice.

BACKGROUND: Despite clear assessment criteria, studies of molar incisor hypomineralisation (MIH) and hypomineralised second primary molars (HSPM) are marked by inconsistency in outcome measurements. This has detracted from meaningful comparisons between studies and limited interpretation.

AIM: To provide a comprehensive manual as a companion to assist researchers in planning epidemiological studies of MIH and HSPM, with particular reference to outcome measurement.

METHODS: This manual begins with a succinct review of the clinical problems and evidence for management of the conditions. The subsequent sections guide researchers through diagnosis of MIH and HSPM and implementation of both the long and short forms of a recently proposed grading system. MIH and HSPM can often be confused with fluorosis, enamel hypoplasia, amelogenesis imperfecta, and white spot lesions but can be distinguished by a number of unique clinical features. Based on the grading system, a standardised protocol is proposed for clinical examinations. Intra and inter-examiner reliability is of key importance when outcome measurement is subjective and should be reported in all epidemiological studies of MIH. The manual concludes with an exercise forum aimed to train examiners in the use of the grading system, with answers provided.

CONCLUSION: The use of a standardised protocol, diagnostic and grading criteria will greatly enhance the quality of epidemiological studies of MIH.