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".

[Relationship between occlusal findings and orofacial myofunctional status in primary and mixed dentition. Part I: Prevalence of malocclusions].

AIM: The aim of this study is to provide basic data on the prevalence of malocclusions and orofacial dysfunctions in the primary and early mixed dentition, to examine occlusal relationships in their functional context, and to analyze the need for and potential of orthodontic prevention. SUBJECTS AND METHODS: Occlusal relationships and myofunctional status were evaluated in 766 children in the primary dentition and in 2,275 children in the early mixed dentition. Orthodontic findings in single jaws and intermaxillary occlusal relationships were clinically analyzed in all three dimensions. RESULTS: Normal occlusal relationships were found in 25.3% of children in the primary dentition. Frequency of children with normal dentitions fell significantly in the mixed dentition (7.3%). Prevalence of bilateral distoclusion increased significantly from the primary to the mixed dentition. Increased maxillary overjet was diagnosed in 49.3% and 59.0% of the children in the primary and mixed dentition, respectively. Prevalence of lateral crossbites increased significantly from primary to mixed dentition (7.2% vs. 12.0%). Deep bites and edge-to-edge bites were found significantly more often in the early mixed dentition. CONCLUSIONS: The significant increase in the prevalence of malocclusions between the primary and mixed dentition--distoclusion and lateral crossbite, and the impairment of vertical occlusal relationships in the mixed dentition in particular--reveal the need for orthodontic prevention. They highlight the absence of applied interceptive and early treatment measures in orthodontics. The indication system in current use for early orthodontic treatment here in Germany fails to fulfill the requirements for prevention-oriented dental care.