A systematic review and meta‐analysis of systemic exposure associated with molar incisor hypomineralization

Abstract

Objective: To evaluate systemic exposures associated with molar incisor hypomineralization (MIH). Methods: This systematic review was performed using published observational studies that evaluated the systemic exposures associated with MIH. The sources of articles searched were PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library and Grey literature. The risk of bias was analysed according to the Newcastle-Ottawa Scale for quality assessment. The meta-analysis was performed considering the exposures during the prenatal, perinatal and postnatal periods using the CMA software.Results: A total of 4207 articles were identified. Twenty-nine studies were eligible for inclusion and 27 were included in the meta-analysis. The studies presented low and moderate risks of bias, except for one that was classified as having a high risk of bias. Maternal illness during pregnancy (OR 1.40; 95% CI 1.18-1.65, P < 0.0001) and psychological stress (OR = 2.65; 95% CI 1.52-4.63; P = 0.001) was observed to be significantly associated with higher odds of MIH. During the perinatal period, caesarean delivery (OR = 1.32, 95% CI 1.11-1.57, P = 0.001) and delivery complications (OR = 2.06; 95% CI 1.47-2.88, P < 0.0001) were also associated with MIH. In the postnatal period, only respiratory diseases (OR = 1.98; 95% CI 1.45-2.70, P < 0.0001) and fever (OR = 1.50; 95% CI 1.22-1.84; P < 0.0001) were associated with higher prevalence of MIH. The evidence was graded as very low quality. Conclusions:Maternal illness, psychological stress, caesarean delivery, delivery complications, respiratory diseases and fever during the first years of a child's life were significantly associated with a higher odds of MIH. However, this should be interpreted with caution, once the primary studies were observational, with serious limitations according to the risk of bias, imprecision, and inconsistency. Further, welldesigned cohort studies are still required. K E Y W O R D Saetiology, dentition, meta-analysis, molar incisor hypomineralization, systematic review | CON CLUS IONAccording to this systematic review, maternal illness, psychological stress, caesarean delivery, delivery complications, respiratory diseases, fever and childhood illnesses were significantly associated with MIH. However, as the evidence was gathered from studies with serious limitations, such as the risk of bias, imprecision and inconsistency, these results should be interpreted with caution.

Pathogenesis of Molar Hypomineralisation: Hypomineralised 6-Year Molars Contain Traces of Fetal Serum Albumin

“…Further efforts to address these challenges are warranted given the double attractions of gaining unprecedented spatiotemporal resolution (i.e., biomarker analysis of individual opacities) and identifying a narrower risk window for MH. Presently, aetiological investigations are hampered by poor understanding of the vulnerability period (reportedly extending from late prenatal to 3-4 years old for 6-year molars; Beentjes et al, 2002;Fagrell et al, 2013;Silva et al, 2016;Fatturi et al, 2019) during which myriad maternal and childhood illnesses prevail.…”

“…Longheld dogma maintains that demarcated opacities result from systemic disturbance of enamel-forming cells (ameloblasts) during the hardening (maturation) stage of enamel formation (Suckling, 1989;Suga, 1989;Jalevik et al, 2001;Weerheijm, 2003;Alaluusua, 2010;Fagrell et al, 2013;Babajko et al, 2017). Yet, despite bolstering general links to childhood illness, numerous epidemiological and laboratory studies have failed to identify a specific cause or pathomechanism (Alaluusua, 2010;Silva et al, 2016;Fatturi et al, 2019;Silva et al, 2019). In 2010, two proteomic investigations showed that chalky enamel opacities contained unusually high amounts of protein, including serum albumin and other derivatives of blood and saliva (Farah et al, 2010;Mangum et al, 2010).…”

Tooth Enamel and Its Dynamic Protein Matrix

“…The staggering prevalence is globally 15% but 30% in the US [ 128 , 129 ]. Although the etiology of MH is still unknown, it is clear that an excess of retained organic matter compromises enamel mineralization [ 92 , 130 , 131 , 132 , 133 , 134 ]. The affected children experience severe pain and sensitivity and MH teeth are prone to caries, abrasion and fracture requiring surface coverage with fillings or replacement of the entire tooth crown or tooth extraction.…”

Gene-environment interaction in molar-incisor hypomineralization

“…Different systematic reviews concluded that most of the previously studied environmental factors that were believed to be risk factors for MIH did not fully explain the disease etiology [5,26,27]. In contrast, etiological factors associated with enamel forming genes [2,28] or in immune response-related genes [28,29] have been reported to play a role in the condition's onset.…”