Associations between oral habits and specific malocclusion traits in children: a retrospective cross-sectional study in Italy

Abstract

Background: Several factors, including feeding methods, food texture and oral habits, are closely associated with malocclusions. This study aimed to assess the associations between malocclusion and oral habits in Italian children aged 6–12 years.

Methods: A retrospective cross-sectional epidemiological study was conducted on a sample of 190 children in the University Dental Clinic of Perugia, Italy, between January 2023 And January 2024. Medical records, complete with questionnaires and clinical dental examinations, were used to analyze the presence of malocclusions and their associations with oral habits (breastfeeding, bottle feeding, pacifier use, finger sucking, dysfunctional swallowing, mouth breathing, onychophagy, object biting, and short lingual frenulum). The participants were divided into two groups: with and without malocclusion. Children with malocclusion were further categorized into subgroups on the basis of Angle’s classification (Class I/II/III), overjet (normal/increased/reversed), and overbite (normal/deep/open).

Results: Among 190 evaluated patients, 72.26% presented with malocclusion. Of these patients, 39.47% had Class II or Class III malocclusions (31.05% And 8.42%, respectively). An increased overjet was observed in 44.21% of the patients, whereas 3.16% exhibited a reverse overjet. An open bite was present in 15.26% of the samples, whereas a deep bite was observed in 33.16%. Among the most common oral habits, dysfunctional swallowing was significantly associated with all the malocclusions observed. The relative risk ratio of having a class II or a class III dental class was greater for those who presented dysfunctional swallowing (RRR 4.24, 95% CI 1.51-11. 88, p = 0.006) and (RRR 10.17, 95% CI: 1.14–80.60, p = 0.038), respectively, compared with Class I. Similarly, the presence of dysfunctional swallowing increases the risk of having an increased overjet (RRR of 5.85, 95% CI: 2.23–15.36, p < 0.001) and opening overbite (RRR of 10.82 95% CI: 1.28–90.97, p = 0.028). The risk of malocclusion increases with the number of harmful oral habits present.

Conclusion: This study revealed an association between different types of malocclusion and oral habits. Multinomial logistic regression analysis identified dysfunctional swallowing as an independent risk factor for Class II and III malocclusions, increased overjet and open bite. This study emphasizes the cumulative impact of oral habits on malocclusion. Ongoing monitoring and multidisciplinary assessments are crucial for improving prevention and treatment. These findings highlight the potential clinical relevance of early identification and implementation of preventive strategies.

Supplementary Information: The online version contains supplementary material available at 10.1186/s12903-025-06892-5.

Keywords: Childhood; Epidemiology; Malocclusion; Oral habits.