Which are the clinical consequences of Molar Incisor hypomineralization (MIH) in children and adolescents? Systematic review and meta-analysis.

OBJECTIVE: This systematic review was conducted to address the following research question: "What are the clinical consequences (outcome) of Molar Incisor Hypomineralization (MIH) (exposure) in children and adolescents (population/patient)?". MATERIAL AND METHODS: After defining the strategy, a search was performed in different databases (MEDLINE via Pubmed, Cochrane Library, BBO, LILACS, Scopus, Web of Science, Embase) and Grey literature in August 2023. Cross-sectional observational studies that identified clinical consequences of MIH (dental caries, post-eruptive structural loss, atypical restorations, hypersensitivity and tooth extraction) were included. The risk of bias was assessed following the Joanna Briggs Institute protocol for cross-sectional studies. Meta-analyses were conducted for each outcome, taking into account the number of patients and teeth. The effect measure considered was the prevalence; random-effects model was adopted. Heterogeneity was assessed using I2 statistics and prediction intervals (PI). RESULTS: A total of 903 studies were identified; 41 were selected for qualitative analysis and 38 for quantitative analysis. Twenty eight studies were classified as presenting uncertain risk of bias, 11 as low risk and 3 as high risk of bias. The prevalence levels, ranked from highest to lowest and considering the tooth and patient units, respectively, were: caries lesions (0.252 - 95% CI 0.158-0.375; 0.512 - 95% CI 0.385-0.639); hypersensitivity (0.286 - 95% CI 0.190-0.407; 0.417 - 95% CI 0.197-0.674), post-eruptive fracture (0.125 - 95% CI 0.099-0.158; 0.257 - 95% CI 0.145-0.412); atypical restorations (0.048 - 95% CI 0.030-0.077; 0.167 - 95% CI 0.096 - 0.274); tooth extraction (0.012 - 95% CI 0.007-0.019; 0.090 - 95% CI 0.019 - 0.331). All meta-analyses resulted in heterogeneity greater than 85%, with the exception of the outcome "tooth extraction" according to the tooth unit (I2 = 57.83). This heterogeneity may be attributed to factors such as differences in the location where the study was realized, the socioeconomic conditions of the studied population, the asymmetric nature of MIH, and patient age. CONCLUSION: The most common consequences of MIH are caries lesions, hypersensitivity, and post-eruptive breakdown. (PROSPERO:CRD42020201410).

Molar-Incisor Hypomineralization: Prevalence Comparative Study in 6 Years of Interval.

The aim of this study was to evaluate the prevalence evolution rate of MIH (molar-incisor hypomineralization) after a 6-year period in Araraquara/SP, Brazil. This population-based study evaluated MIH in 545 schoolchildren (6-12 years of age) and other associated alterations, dental caries and dental fluorosis (DF). A semistructured questionnaire was sent to the schoolchildren's parents/guardians with the purpose of identifying the socioeconomic profile. Associations between MIH and the clinical characteristics were analyzed by the Poisson analysis of regression with robust variance, estimating the RPc (crude prevalence ratio) with CI 95%. The level of significance of 5% was adopted. The MIH prevalence in Araraquara/SP in 2016 was 14.3% (n = 78), and at this time, an increase of 2% was observed, in comparison with the data of the first prevalence study conducted in 2010 (12.3%). The mild degree compromise was the most prevalent diagnosis in the affected teeth (82.0%). Among children with MIH, the mean number of affected teeth was 2.78. Of the total number of children with MIH, 32.0% presented alterations in both first permanent molars and permanent incisors. There is no significant association between MIH and dental caries experience on permanent dentition (PRc = 1.141; CI 95% 0.709-1.835) or on primary dentition (PR c = 1.132; CI 95% 0.749-1.709). Children with MIH presented significantly less prevalence of dental fluorosis (PR c = 0.505; CI 95% 0.268-0.950). There is no association between MIH and monthly Brazilian minimal wage income (PR c = 1.130; CI 95% 0.655-1.949). It was concluded that the number of MIH cases had increased, revealing a greater need for defining the etiological factors and establishing a correct diagnosis to make it possible to institute early intervention.

Unexpected formation of root-like structures subsequent to the avulsion of immature permanent teeth: Case report.

This report describes the unexpected formation of root-like structures following the avulsion of immature permanent teeth without replantation. A 6-year-old female patient had avulsed the four permanent mandibular incisors and the two deciduous mandibular canines. The patient was seen in an emergency healthcare unit but did not receive specialized treatment for tooth replantation. As follow-up treatment, she received a removable prosthesis. After 4 years of follow-up, an image obtained by panoramic radiography showed formations similar to four root structures in the alveolus of the previously avulsed permanent teeth. This finding was confirmed by periapical radiography and computed tomography. This case report demonstrates that in teeth with incomplete root development, even after avulsion without replantation, cells from the pulp stump may have the capacity to form mineralized structures that appear radiographically comparable to root dentin.

Is catechol-O-methyltransferase gene associated with temporomandibular disorders? A systematic review and meta-analysis.

BACKGROUND: Temporomandibular disorder (TMD) is a condition, in which multiple factors act synergistically to determine the outcome of the disorder. AIM: A systematic review and meta-analysis was conducted to evaluate the association between genetic polymorphisms in catechol-O-methyltransferase (COMT) and TMD. DESIGN: Observational studies that investigated this association were included. The risk of bias and study quality were evaluated according to the Newcastle-Ottawa tool. The meta-analysis was performed for each polymorphism associated with TMD signs and symptoms. RESULTS: A total of 1903 articles were identified. Ten remained in the qualitative analysis: six were classified as low risk of bias and four with moderate risk of bias, and three were included in the meta-analysis. The polymorphism rs6269, in the genotypic model (0.65; CI = 0.44-0.97; P = .04) and in the allelic model (0.73; CI = 0.54-0.98; P = .04), was associated with myofascial pain. The rs9332377 was associated with myofascial pain in the genotypic model (2.69; CI = 1.51-4.76; P = .0007) and in the allelic model (1.46; CI = 1.01-2.13; P = .05) and with painful TMD in the genotypic model (2.08; CI = 1.27-3.40; P = .004) and in the allelic model (1.34 CI = 0.98-1.82; P = .06). CONCLUSION: The polymorphisms in COMT were significantly associated with TMD.

Longitudinal Evaluation of the Structural Integrity of Teeth Affected by Molar Incisor Hypomineralisation.

The aim of this prospective cohort study was to evaluate the risk of posteruptive breakdown and the development of caries lesions in teeth with molar incisor hypomineralisation (MIH). A total of 367 permanent incisors and first molars, affected and not affected by MIH lesions, of 45 children with MIH from Araraquara, São Paulo, Brazil, were evaluated at intervals from 6 to 12 months by assessing the severity of MIH, the presence of tooth caries lesions and the treatment needed. During the study period, all patients received preventive care. The data were analysed using Fisher's exact test and actuarial method survival analysis. Significant associations were also found in teeth between the presence of MIH and a DMFT index >0 in all periods and also between the need for treatment and the presence of MIH. The teeth affected by MIH opacities were healthy in 99% of incisors and 93% of molars at the end of the 12-month period. Due to the high likelihood of maintaining the tooth structure in opacities, the complete or premature removal of the affected area is not justified.

Hipomineralización incisivo y molar: diagnóstico diferencial / Incisor and molar Hypomineralization: differential diagnosis

La hipomineralización de primeros molares frecuentemente es acompañada con una hipomineralización de incisivos (HIM - Hipomineralización Incisivo y Molar) esto es comúnmente encontrado en la práctica clínica. El esmalte hipomineralizado es frágil, puede fracturarse y dejar expuesta la dentina, causando sensibilidad dental y aumento del riesgo de caries. La prevalencia de HIM varía de 3,6 a 25% en el norte de Europa, siendo considerada un problema de salud pública. En cuanto a los factores etiológicos los datos no son definidos, por lo cual causas sistémicas parecen importantes. Los posibles factores etiológicos de este cambio son a menudo relacionados con problemas en el embarazo y enfermedades de la infancia en los tres primeros años de vida. El HIM es frecuentemente confundido con otros defectos del esmalte como amelogénesis imperfecta, la fluorosis y la hipoplasia, sin embargo, detalles sobre las características clínicas de esta condición pueden diferenciarlo de otros defectos del esmalt

Hypomineralized first molar often in combination with hypomineralized incisors (MIH - molar incisor hypomineralization) is a common finding in everyday practice. In this condition, hypomineralized dental enamel is fragile and soft, and it can break easily leading to an exposed dentin, and causing dental sensitivity and progression of caries lesions. The prevalence of MIH range from 3.6 to 25% in North of Europe that consider this condition a public health problem. No conclusive information was reported about the etiologic factors of MIH, however, systemic causes seem to be of importance. Several aetiological factors are mentioned as the cause of this condition and they are frequently associated with complications during pregnancy and childhood diseases during the first three years of life. MIH is frequently misinterpreted as fluorosis, hypoplasia or amelogénesis imperfect, however, this condition presents defined clinical aspects that can distinct it from the other defects

Hipominerazación de incisivos y molares: aspectos clínicos de la severidad / Molar and incisors hypomineralization: clinical aspects of the severity

La hipomineralización de incisivos y molares (HIM) es un trastorno de desarrollo de los primeros molares y de los incisivos permanentes. El esmalte afectado es frágil y fácilmente se puede desprender dejando expuesta la dentina, lo cual favorece la sensibilidad dentinaria y el desarrollo de lesiones cariosas. Los posibles factores etiológicos se asocian a alteraciones durante la gestación y a algunas enfermedades de la primera infancia. El tratamiento depende de la severidad del caso y puede incluir restauraciones de los dientes cariados, extracciones cuando estén indicadas, conservación y/o recuperación del espacio mediante aparatología ortodóncica. Los pacientes afectados por HIM exhiben signos y síntomas clínicos definidos, ello permite clasificarlos de acuerdo con la severidad y con las características de la hipomineralización. El objetivo de este trabajo es presentar las características clínicas asociadas con la hypomineralization incisivo-molar, de niños de 6 a 12 años de edad que asisten a la clínica de Estudios de Posgrado, la disciplina de Odontología Pediátrica de la Facultad de Odontología de Araraquara, UNESP, para ayudar al cirujano dentista en el diagnóstico y la toma de decisiones en el tratamiento

Molar-Incisor Hypomineralization (MIH) is an enamel development defect affecting one to four permanent first molars frequently associated with affected incisors. The enamel breakdown is common in the affected molars resulting in hypersensitivity and to dental caries development. The possible etiological factors are associated with systemic cause occurring in pregnancy, around the time of birth or in the first childhood. The treatment depends of the defect severity, and includes restorations and extractions of the teeth associated with orthodontic treatment in tooth severely affected. The aim of this study is present clinic characteristics relative to MIH in children aged 6 to 12 years treated and accompanied in Pediatric Dentistry Clinic of the Araraquara School of Dentistry, UNESP, to help dentistry in diagnosis and treatment plan