Influence of genetics on the occurrence of enamel hypomineralization affecting permanent and primary teeth: A scoping review

Background Molar incisor hypomineralization (MIH) is prevalent worldwide and is a challenge for clinicians who provide oral care to children. Molar incisor hypomineralization has been considered a multifactorial disturbance that results from a combination of environmental and genetic factors. Aim This scoping review followed the Joanna Briggs Institute protocol and aimed to identify the available evidence of the genetic influence on the etiology of MIH. Design The search strategy was conducted in multiple databases, including PubMed, BVS, Embase, Web of Science, and Scopus. Two trained reviewers, requiring a third reviewer in case of disagreements, collected evidence. Results Of 563 retrieved studies, 17 were included in the review. From 14 studies performed in humans, 10 investigated DNA polymorphisms, one analyzed DNA methylation, one aimed model of inheritance, and two focused on the phenotype in twins or in the family. Three animal studies were based on the null expression of genes. Conclusion This scoping review, based on the studies that used different methodologies, reinforces the hypothesis of a genetic contribution to the multifactorial etiology of MIH. The available data are limited in terms of size and origin of the samples. Hence, further genetic studies are still required.