Published online Feb 20, 2019. doi: 10.5321/wjs.v7.i2.20
Peer-review started: December 12, 2018
First decision: January 4, 2019
Revised: January 14, 2019
Accepted: January 28, 2019
Article in press: January 28, 2019
Published online: February 20, 2019
The aim of this study is to report the diagnostic features, prevalence, mineral content, clinical significance and treatment options of molar incisor hypomineralization (MIH) and pre-eruptive intracoronal lesions (PEIR), in order to minimize miss-treatment of primary and permanent teeth in young children. MIH was defined as the occurrence of hypomineralization of one up to four permanent first molars from a systemic origin and frequently associated with affected incisors. PEIR are lesions that are located in the occlusal portion of the crown of unerupted permanent or primary teeth. The prevalence of MIH was reported between 2.5%-40% in the permanent first molars and 0%-21.8% in primary second molars. PEIR was observed in 2%-8% of children, mainly in mandibular second premolars and second and third permanent molars. A number of possible causes for MIH were mentioned, including environmental changes, diet and genetics in prenatal and postnatal periods, but all are questionable. In PEIR, the resorption of the intracoronal dentine begins only after crown development is complete and is caused by giant cells resembling osteoclast observed histologically on the dentine surface close to the pulp. The mineral content in MIH is reduced in comparison to normal enamel and dependent on the severity of the lesion. In PEIR the resorbed surface of enamel showed less mineral content. The hypomineralized enamel in MIH is not suitable for restorations with amalgam or composite materials, and the best material should be based on remineralization material like glass-ionomers. Similar, the resorbed dentin surface in PEIR should be covered by the biocompatible and re-mineralizing glass-ionomer cement.
Core tip: Molar incisor hypomineralization and pre-eruptive intracoronal lesions are an increasing concern in pediatric dentistry. Since both conditions are developmental and not caused by carious attack, correct diagnosis of the conditions is significant in order to successfully treat the teeth. Early diagnosis can improve the survival rate of these teeth, because breakdown of the enamel can occur in both lesions and subsequent carious attack may lead to pulpal involvement and extraction of teeth at a very young age. The optional restorative material should be based on the re-mineralizing properties of glass-ionomer cements.