Electropalatographic and cephalometric assessment of tongue function in open bite and non-open bite subjects

Anterior open bite (AOB) and tongue thrust swallowing are frequently associated, but the relationship between the two remains unclear. Electropalatography (EPG), which is used in speech pathology to measure dynamic tongue function for diagnostic, therapeutic, and research purposes, is a suitable technique for the investigation of this relationship. The present clinical study examined the dentofacial pattern and tongue function in AOB and non-open bite children. EPG recordings of speech and swallowing, and lateral head radiographs were obtained from eight 10-year-old boys with tongue thrust swallowing behaviour and AOB, and from eight age-matched non-open bite controls. Analysis of data from the two groups indicated that although differences were small, the open bite children displayed trends 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. The discovery of differing patterns of contact for the /d(3)/ and /t integral/ phonemes indicates that these should be included when speech is used to test for the presence of fronted tongue behaviour.