Hypomineralised second primary molars may be indicative of future molar incisor hypomineralisation


General dental practitioners should be familiar with the signs of hypomineralised second primary molars (HSPM), as these children are high caries risk and may be more likely to develop molar incisor hypomineralisation (MIH).


Background: The term hypomineralised second primary molars (HSPM) describes a prevalent qualitative developmental defect of enamel. Children with HSPM are at a high risk of caries, and are reportedly five times more likely to develop molar incisor hypomineralisation (MIH).

Aetiology: There is an overlap in the development of the second primary molar and the first permanent molar. It is likely that MIH and HSPM have some shared aetiological factors, but in the case of HSPM the insult likely occurred earlier.

Diagnosis: HSPM can be identified as soon as the second primary molar erupts. It has a distinct clinical presentation and many clinical similarities with MIH. HSPM should be differentiated from typical early childhood caries.

Conclusion: Early dental visits for all children would allow early diagnosis of HSPM, which is essential to prevent future problems. Dental teams who work with children should be familiar with the signs of HSPM and use high caries risk preventive strategies, as well as increased vigilance during eruption of the first permanent molars.

Journal of the Irish Dental Association December 2019/January 2020; 65 (6): 340-345

Dr Rona Leith
Assistant Professor in Paediatric Dentistry
Dept. of Public & Child Dental Health, Dublin Dental University Hospital, Lincoln Place, Dublin

Corresponding author: Dr Rona Leith. T: 01-612 7303 E: rona.leith@dental.tcd.ie