The effect of myofunctional therapy in anterior open bite patients measured by electropalatography

Abstract

Anterior open bite (AOB) and tongue thrust swallowing are frequently associated, but the relationship between the two remains unclear. Anterior tongue posture may prevent the eruption of the anterior teeth, and myofunctional therapy (MFT) is often prescribed for the correction of tongue thrust swallowing, with the expectation that AOB will reduce spontaneously if a more posterior tongue posture is learned. However, the effectiveness of MFT has not been subjected to systematic evaluation. Electropalatography (EPG), which is widely used in speech pathology to measure dynamic tongue function for diagnostic, therapeutic and research purposes, is a suitable technique for the assessment of MFT. This prospective clinical study examined dento-facial pattern and tongue function in AOB and non-open bite children, and assessed the effect of tongue re-education therapy on dento-facial form and tongue function in AOB patients. EPG recordings of speech and swallowing, and lateral head radiographs were obtained from 8 ten year old boys with tongue thrust swallowing behaviour and AOB, and 8 age matched non-open bite controls. Analysis of data from the two groups indicated that although differences were small, the open bite children displayed tlends for longer face morphology and greater upper incisor proclination, less consistent production of closures during speech, a more posterior pattern of EPG contact, and relatively sparse EPG contact during swallowing. Comparison of the condition of the AOB children before and after a course of tongue re-education therapy showed little cephalometric change, but there was some evidence of a trend for upper and lower incisor eruption, with concomitant reduction of the AOB. A trend for more consistent, and more anterior pattern of EPG contact after therapy was also found. After therapy, the experimental children more closely resembled the controls, implying that the therapy was at least partially successful.