Linking the Clinical Presentation of Molar-incisor Hypomineralisation to Its Mineral Density

Background: The in vitro methods used for the assessment of the severity of molar-incisor hypomineralisation (MIH) are not available for clinicians faced with questions regarding the severity in clinical cases, and the best management approach.

Aim: To assess whether there is a relation between the severity of the defects in MIH enamel (represented by reduction in the mineral density) and the clinical presentation (represented by the colour of the defect and its laser fluorescence).

Design: The colour of enamel was recorded (normal, white, yellow or brown) in specific areas for ten extracted first permanent molars with MIH defects and ten extracted sound teeth. Laser fluorescence (LF) and mineral density (MD) were measured for the same areas. A mixed model, using sample/tooth as a random effect, was used to estimate the relationship between the MD and the colour-coding, and between the MD and LF readings.

Results: The between-samples correlation coefficient for the colour coding and the MD was 0.99 (P < 0.001), and 0.83 (P < 0.001) for the LF and MD.

Conclusions: The degree of staining of MIH enamel, as assessed visually or by LF, may be used clinically to reflect the severity of the defect.