Association between malocclusion and orofacial myofunctional disorders of pre-school children in Latvia

Objects: Abnormal use of muscles of tongue and lips is called orofacial myofunctional disorders (OMD). In this study, we aimed to investigate the interrelation between occlusal findings and OMD in primary and mixed dentition and to find out the reasons for malocclusions, and the effect modification of these associations by the number of sources that parents used to receive the information on child oral health issues (NSI). Setting and sample population: Cross-sectional study was performed in one kindergarten in Latvia (cluster sampling). The study sample comprised 141 children-mothers’ pairs of pre-school children aged 4-7 years. Materials and methods: Children’ myofunctional situation, occlusion and speech defects were assessed during an examination. Children's mothers were interviewed on their socio-demographic situation, feeding and habits of the child, history of diseases and NSI. Multiple logistic regression models adjusted for lip power, swallowing, breathing and speech cases of long respiratory diseases, age and gender were built to investigate associations between the types of occlusion and OMD/health characteristics. Effect modification of these associations by NSI was analysed. Results: Types of occlusion associated with OMD/health characteristics were as follows: normal occlusion with prolonged respiratory diseases (odds ratio, OR = 0.345 [95% confidence interval, CI 0.16; 0.75]); combined type with tongue thrust habits (OR = 3.11 [0.99; 9.90]), lip-closing strength (OR = 0.99 [0.98; 0.99]); and cross-bite with speech (OR = 3.55 [1.07; 11.78]). These associations remained stable when parents used two or less sources of information on children's oral health. Conclusions: To facilitate occlusal stability, early interdisciplinary examinations should be performed to prevent time-consuming and cost-consuming treatment.