Aim: This cross-sectional study was carried out to evaluate the prevalence of malocclusion and associated factors in preschoolers with the aim of assessing the existence of an association between bad habits and mouth breathing with the most severe malocclusions.
Materials and methods: A sample of 1616 children aged 3-6 years was visited by applying the Baby ROMA index, an orthodontic treatment need index for preschool age. The following were searched: the prevalence of malocclusion, the association of bad habits and mouth breathing with malocclusion, how often are found in association and how this association is statistically significant. Chi-square and Fischer test were applied to verify the statistical significance of the association between the variables.
Results: The data show that 38% of the sample need orthodontic treatment and 46% have signs of malocclusion of less severe degree that require a close monitoring and the elimination of risk factors so that they can improve spontaneously with growth. Moreover the prevalence of bad habits and oral breathing increases with increasing severity of the malocclusion, and sucking habits and oral breathing are both closely related to anterior open bite, posterior crossbite and increased overjet.
Conclusions: In the context of prevention and early treatment of disorders of the craniofacial growth, bad habits and mouth breathing, being risk factors of malocclusion, should be intercepted and corrected early on to prevent the development of malocclusion, or the worsening of existing ones. From this point of view it is important to follow the patients with a multidisciplinary approach.