Relationship between occlusal findings and orofacial myofunctional status in primary and mixed dentition. Part II: Prevalence of orofacial dysfunctions.

AIM: The aim of this study was to provide basic data on the prevalence of orofacial dysfunctions in primary and early mixed dentition and to examine occlusal relationships in their functional context, and to analyze the need for and potential of orthodontic prevention and early treatment. SUBJECTS AND METHODS: We assessed the occlusal relationships and myofunctional status of 3,041 children. The presence of dynamic and static myofunctional disorders and any oral habits were documented during functional analysis.
RESULTS: The frequency of myofunctional disorders was statistically significantly higher in children with increased maxillary overjet, frontal open bite, lateral crossbite and mandibular prognathism, and there was a statistically significant increase in the prevalence of orofacial dysfunctions and oral habits from primary to mixed dentitions.
CONCLUSIONS: Habitual open mouth posture (expressing hypotonia in the perioral muscles) and a visceral swallowing pattern become established during the primary dentition and are increasingly carried over into the mixed dentition period. Both criteria, along with assessment of occlusal relationships, are appropriate parameters with which to identify "children at risk for orthodontic treatment".