RELIABILITY OF ELECTROMAGNETIC ARTICULOGRAPHY RECORDING DURING SPEAKING SEQUENCES

For the development of malocclusions and speech disorders, major aetio logical significance is attributed to orofacial malfunctions, especial ly of the tongue. The position of the tongue to the alveolar arch and teeth, particularly within the area of the tip of the tongue, is of sp ecial interest for orthodontists. Electromagnetic articulography is a new technique used to examine tongue function and to record its moveme nt in the midsagittal plane. The aim of the study was to determine whe ther this procedure offers suitable and reliable results. Thirty-one s ubjects aged 14.3-37.3 years had to repeat speaking sequences five tim es. The German syllables they had to repeat were /asa/, /ascha/, /ata/ , /ala/, /ana/, /aka/. The tongue movements were registered with an 'A rticulograph AG 100 (R),'. Distances, angles and encircled planes were evaluated, and the proportion of intra-individual to overall variabil ity was calculated in order to check the reliability of the courses of movement. Angles and distances especially showed, depending on the po sition of the receiver coils, strong reliability during speaking seque nces, whereas area produced unfavourable results. The analysis of long trajectories and angles appeared favourable in order to describe the courses of movement. This required, however, a systematic assessment o f functional movement with electromagnetic articulography.