08 August 2023

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MIH, a problem that can greatly affect the lives of patients

By Arianna Bianchi

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Molar and incisor hypomineralization (MIH) is a well-recognized enamel quality defect, which can involve one to four permanent first molars, often the permanent incisors.

MIH is associated with hypersensitivity, difficulties in obtaining adequate anesthesia, atypical carious lesions and cosmetic problems that are concerning to the patients who suffer from it.

The etiology is multifactorial, and MIH is thought to be the result of the action of several factors that influence enamel formation during the pre-, peri- and immediately post-natal phases (up to about three years of age). 

Recently, some studies suggested that genetic or epigenetic modifications may determine the development of MIH. The treatment of teeth affected by MIH is complex and providers must factor in the patient's cooperation, the stage of dental development and the severity of the enamel defect.

Materials and methods

In a systematic review published in June 2021 in the European Archives of Paediatric Dentistry, the authors considered all randomized controlled trials (RCTs), including cluster RCTs, controlled (non-randomized) trials, case-control, cross-sectional and longitudinal studies, while case series, with a minimum of 10 patients, were included only with the consent of all authors. The team did not consider animal or in vitro studies.

All selected studies had participants under the age of 18 and all possible interventions performed for teeth affected by MIH were considered.

Regarding the outcomes, due to the wide variety of treatment options and the different outcomes established by the numerous studies, the success of the intervention was considered as the main outcome measure.

Secondary outcomes were intervention longevity, annual failure rate, quality of life, aesthetics, function, adverse events and patient, parental and dentist satisfaction with the outcome.

Results 

Researchers identified 6,220 articles, resulting in 4,499 after removing the duplicates. Seventy-seven studies then underwent a full textual review, and 34 of these met all inclusion criteria for the systematic review. For molars affected by MIH, among the various studies selected for this systematic review, a total of 1711 teeth were examined.

Studies have used different techniques to treat teeth affected by MIH, such as resin-based fissure sealants, glass ionomer restoratives, “classical” or polyacid-modified composites, amalgam restorations, crowns made in the laboratory or indirect restorations in composite material. 

For the anterior elements affected by MIH, on the other hand, despite the incisors being the subject of greater aesthetic interest, only 105 dental elements were considered, since many studies examined focused the research more on the diatoric elements than on the anterior ones. 

In the studies considered for this review, three investigated resin infiltration while one evaluated the efficacy of two different microabrasion approaches for the treatment of MIH. 

Some studies have investigated the reduction of hypersensitivity for teeth affected by MIH, considering a total of 402 elements. Various methods have been used, such as 5% fluoride varnish (also in combination with low laser therapy), a 10% CPP-ACP cream (casein phosphopeptide complex - amorphous calcium phosphate), 1000 ppm fluoride toothpastes, a toothpaste with 8% arginine and calcium carbonate. 

Conclusions 

According to the data obtained from this systematic review, for molars affected by MIH there is convincing evidence mainly supporting the use of resinous fissure sealants, pre-formed metal crowns and direct composite resin or laboratory-fabricated restorations, while amalgam restorations should be avoided. 

For the anterior teeth, however, there is evidence to support any type of intervention. Some studies have demonstrated the possible beneficial use of products containing CPP-ACP for the treatment of teeth affected by MIH, especially to reduce the effects of hypersensitivity induced by MIH itself. According to the authors, further high-quality studies are needed with more participants, longer follow up periods and more clinically relevant and appropriate outcome measures in the management of MIH-affected teeth.

Somani, C., Taylor, G.D., Garot, E. et al. "An update of treatment modalities in children and adolescents with teeth affected by molar incisor hypomineralisation (MIH): a systematic review." Eur Arch Paediatr Dent 23, 39–64 (2022). https://doi.org/10.1007/s40368-021-00635-0.