Influence of Incisor Molar Hypomineralization on children's chewing performance: A cross-sectional study

um estudo transversal

Abstract

Introduction/Justification: Masticatory performance (MP) refers to the ability of oral structures to adequately grind food and is of great importance in the development of the stomatognathic system. Among the means of evaluation, masticatory function can be measured by assessing masticatory performance (MP), which consists of the individual's ability to grind or crush a sample of particles (test food) after a standardized number of chewing cycles. Thus, the smaller the particle size, the more efficient the breakdown of food molecules, which has direct implications for growth and development, especially in children, since good chewing allows for faster hydrolysis of macronutrients and better molecular diffusion, resulting in better nutrient absorption. HMI (Hypercutaneous Mellitus) is a qualitative defect in the development of dental enamel, of multifactorial origin, affecting at least one of the first permanent molars, with or without association with the incisors, clinically characterized by the presence of well-defined opacities that vary in color from white to yellowish-brown. The affected dental enamel presents lower mineral content, hardness, and modulus of elasticity, in addition to increased porosity, resulting in a softened enamel consistency that fractures easily under the forces of mastication. Due to this, patients with HMI face a series of clinical problems, such as aesthetic dissatisfaction, loss of restorations, need for reinterventions, post-eruptive fractures, presence of atypical caries, dentin hypersensitivity in response to temperature variations and/or mechanical stimuli, and pain, especially during mastication, directly impacting their quality of life. Methodology: This is a cross-sectional study, approved by the Ethics and Research Committee of the Federal University of the Jequitinhonha and Mucuri Valleys under protocol number 1.525.953, with a sample of 324 children aged between seven and twelve years enrolled in public schools in the city of Diamantina-MG, Brazil, who had their four first permanent molars in occlusion. The sample size was determined using the OpenEpi platform, employing data from the pilot study: median particle size in children without HMI (mean: 2.61, standard deviation: 0.85) and with HMI (mean 2.91, standard deviation 0.88). A sample of 246 participants was required for the study. However, considering potential losses, 324 children were recruited. The sample was recruited by convenience in six schools in the city. Individuals with systemic or neurological disorders, such as Down syndrome or cerebral palsy, those taking medications capable of affecting muscle activity, such as antidepressants, muscle relaxants or sedatives, those using orthodontic appliances, as well as those who did not cooperate with the clinical examination and/or refused to participate in the research were excluded. Oral clinical examination was performed to assess lower motor neuron disease (LMD), malocclusion, number of teeth lost due to caries, number of masticatory units, and presence of dental caries. For MP assessment, an artificial test food (Optocal) was used, and the processing method was sieving. From the weight of the particles retained in each sieve, the median size (X50) of the crushed particles for each child was determined. All variables were categorized according to their variation during the follow-up period. The risk of impact of the variables on MP was tested using the Kolmogorov-Smirnov, Mann-Whitney, and Kruskal-Wallis tests, as well as simple and multiple linear regression. The significance level adopted was p≤0.05. Results: In the final multiple regression analysis, the average particle size was influenced by the number of masticatory units and the presence of LMD. Conclusion: Schoolchildren with LMD presented worse MP than schoolchildren without LMD. Furthermore, the number of masticatory units was associated with worse MP.