Quantitative examination of isometric tongue protrusion forces in children with oro-facial dysfunctions or myofunctional disorders.

Oro-facial dysfunctions (OFD) or oro-facial myofunctional disorders in children lead to severe problems in teeth and jaw position, articulation, chewing and swallowing. The forces of the tongue, the central muscle for articulation, chewing and swallowing are focused on in several studies. In this examination, isometric tongue protrusion forces (TPF) of children with OFD and controls were compared. Thirty participants with OFD and 30 controls were presented a target force level as a straight line on a monitor that they were supposed to match by generating an isometric tongue force for different target levels (0.25 N and 0.5 N). Correlations of the severity of OFD (symptom score) with the capacities of the TPF 0.25 N and 0.5 N were calculated. Statistical differences were obvious in TPF variability and the accuracy, depending on the weight. Tongue contact time, expressed as per cent (TCT, total contact: 100%), was significantly lower in children with OFD (P = .005). Mean and median TPF was not different between groups. The predictive value of TPF for OFD revealed a level of 58.6% for TPF 0.25 N and 74.5% for TPF 0.5 N. Correlations of the severity of OFD were seen for some parameters. Subjects with OFD show significantly lower competencies in accuracy and endurance of tongue protrusion forces. This may have a high impact on phenotyping children with OFD and influence therapeutical approaches.