To define the prevalence of Molar Incisor Hypomineralization (MIH) in Brazil since the reports ranged from 2.5% to 40.2%. Material and Methods: We studied 407 children from 7 to 14 years of age. MIH was measured using the European Academy of Paediatric Dentistry criteria of 2003. Clinical data were collected by a calibrated dentist (Kappa=0.88) and included affected teeth and degree of MIH severity (mild/severe). Mild MIH cases were considered when the tooth presented demarcated opacity ≥ 1.0mm, without any loss of structure. While severe cases were defined by teeth in which loss of structure was present, or past or current lesion that required treatment, or presence of atypical restorations. In addition, published data (nine studies) reporting MIH in Brazilians were identified, and the heterogeneity of these studies was tested (I2 index/ p≤0.01). Results: In the original sample studied, the majority of patients were males (55.3%; n = 225), with an average age of 10.1 years (± 2.1 years). The prevalence of MIH in this group was 14.5% (59 affected in 407), and most of the affected teeth had a mild degree of alteration (77.4% or 202 in 261 teeth). Conclusion: A meta-analysis including nine published reports, and our original data showed that MIH prevalence in Brazil is 13.48 (95% CI, 8.66%-18.31%).

Employing minimally invasive operative techniques to manage compromised first permanent molars is discussed as a treatment regimen to achieve a favourable medium-to long-term prognosis in modern paediatric dental management. It is known that patient cooperation, stage of dental development and eruption state, as well as chronological age and severity of tissue breakdown of the compromised tooth have an influence on the prognosis of treatment. CPD/Clinical Relevance: Understanding the various prognostic factors involving compromised first permanent molar teeth is essential if optimum treatment is to be provided.

O tratamento ortodôntico experimenta evolução contínua em seus aparelhos, principalmente por questões estéticas e de conforto. Objetivo: avaliar a satisfação e desconforto relatados por pacientes submetidos ao tratamento ortodôntico com bráquetes vestibulares metálicos e cerâmicos, bráquetes linguais e alinhadores Invisalign®. Material e métodos: Aplicação de um questionário padronizado a 126 pacientes de ambos os sexos, em tratamento ortodôntico em consultórios particulares há pelo menos 90 dias, sem outro acessório ortodôntico. Os pacientes foram divididos em 4 grupos: grupo I (n=30) bráquetes vestibulares metá- licos, grupo II (n=30) bráquetes estéticos vestibulares, grupo III (n=32) alinhadores Invisalign® e grupo IV (n=34) bráquetes fixos linguais. A comparação entre os grupos foi feita pelo teste do qui-quadrado e, quando este indicou diferença estatisticamente significativa, foram realizadas comparações múltiplas pelo teste de proporções. Resultados: Os bráquetes metálicos vestibulares foram mais percebidos pelos demais e trouxeram maior desconforto estético. Os bráquetes cerâmicos foram menos percebidos pelos demais do que os bráquetes vestibulares metálicos. Os alinhadores foram menos percebidos pelos outros do que os bráquetes vestibulares, causaram menos dificuldades na fala e na escovação, menos desconforto nas bochechas e menos dificuldades na fala. Os bráquetes linguais trouxeram menos desconforto estético, revelando também maior desconforto na língua e menos desconforto na bochecha. Conclusão: Os pacientes relataram maior desconforto estético com bráquetes vestibulares metálicos. Aparelhos linguais e alinhadores foram menos percebidos pelos demais e trouxeram menos desconforto estético aos pacientes. Todos os pacientes tratados com alinhadores o usariam novamente caso precisassem de um novo tratamento.

Objective: To assess the association between environmental factors during pregnancy and early childhood with the presence and severity of Molar Incisor Hipomineralization (MIH). Material and Methods: This cross-sectional study was conducted with 120 patients between 7 and 14 years of age. MIH was evaluated according to EAPD criteria. Data collected included the child's medical history and the mother's health. Chi-square and logistic regression were performed to determine any statistical evidence of the environmental factors, with the significance level set at 5%. Results: The participants were divided into groups with MIH (n=60) and without MIH (n=60), with average ages of 9.9 (±1.9) and 9.7 (±1.7) years, respectively. There was a statistically significant difference between intercurrences during pregnancy (OR=3.55; IC95%=1.35-10.57) and medication taken by the child (OR=3.01; IC95%=1.74-8.42) and the presence of MIH. In addition, other variables were also associated with the MIH (p≤0.05). However, there was no association with variables and degree of MIH severity (p>0.05). Conclusion: The use of medications in childhood and complications during pregnancy can be association to the presence of MIH. However, these factors do not interaction to MIH severity.