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 associ ated, but the relationship between the two remains unclear. Electropalatogr aphy (EPG), which is used in speech pathology to measure dynamic tongue fun ction for diagnostic, therapeutic, and research purposes, is a suitable tec hnique for the investigation of this relationship. The present clinical study examined the dentofacial pattern and tongue func tion in AOB and non-open bite children. EPG recordings of speech and swallo wing, and lateral head radiographs were obtained from eight 10-year-old boy s with tongue thrust swallowing behaviour and AOB, and from eight age-match ed non-open bite controls. Analysis of data from the two groups indicated that although differences we re small, the open bite children displayed trends for longer face morpholog y and greater upper incisor proclination, less consistent production of clo sures during speech, a more posterior pattern of EPG contact, and relativel y sparse EPG contact during swallowing. The discovery of differing patterns of contact for the /d(3)/ and /t integr al/ phonemes indicates that these should be included when speech is used to test for the presence of fronted tongue behaviour.