Prevalence of malocclusions and dysfunctional oral habits in preschool children of municipal establishments in Viña del Mar.

Introduction: Malocclusions are a public health problem at national and global level, being third in the ranking of the most prevalent oral pathologies.Its origin is multifactorial, with dysfunctional oral habits being a risk factor. The objective of this study was to determine the prevalence of malocclusions and dysfunctional oral habits in students aged between 4 and 6 years in state-run public schools in Vina del Mar, Chile. Material and methods: A prevalence study was carried out in 184 students selected by random cluster sampling. Malocclusions were assessed by clinical examination, while dysfunctional oral habits were assessed by questionnaires and clinical examination. The data were analyzed using Fisher’s exact test, Chi-square test and the PHI correlation coefficient. Results: The prevalence of malocclusions was 54.35% (95% CI [47.04% - 61.47%]), with dental crowding being the most frequent, while prevalence of dysfunctional oral habits was 95.11% (95% CI [90.82% - 97.45%]), led by lingual interposition. In none of the cases statistically significant differences of age, gender or class were noticed. The evidence provided by this study indicates that the presence of malocclusions is independent of the presence of dysfunctional oral habits, except between open bite and interposition of objects, whose magnitude of dependence was minor (0.2). Conclusion: There is a high prevalence of malocclusions and dysfunctional oral habits in preschool children, with dental crowding and lingual interposition being the most frequent, respectively. The presence of malocclusions is independent of the presence of dysfunctional oral habits.