Clinical Characteristics and Differential Diagnosis of Hypomineralised Second Primary Molars and Molar Incisor Hypomineralisation.

Molar incisor hypomineralisation (MIH) and hypomineralised second primary molars (HSPMs) are commonly seen dental developmental problems with a mean prevalence of around 14% and 9%, respectively, but with a large variability in the reported prevalences. From the dental development, we know that the enamel mineralisation of the second primary molar is taking place between the 19th week of pregnancy until 1 year of age. For the first permanent molars (FPMs) and incisors, the enamel mineralisation is taking place between birth until the age of 3-5. When there is a disturbance during this period, HSPM and/or MIH can occur. There is an overlap in the development of the second primary molars and the FPMs and incisors; the period between birth and the first birthday of the child. A disturbance in this period could cause both HSPM and MIH. There is a relation found in the occurrence of HSPM and MIH. Diagnosing HSPM and MIH can be challenging. All teeth present in the mouth need to be examined. The use of the European Association of Paediatric Dentistry scoring criteria is a good help. In these criteria also, the most common differential diagnoses are included.