This study was carried out to clarify the relationship between articulation and patterns of tongue and jaw movement in mandibulectomy patients.
Articulatory movement was synchronously analysed using high-speed 16 mm cinematography and dynamic palatography in twenty mandibulectomy patients and five normal adults. The relationship between articulatory movement analysed and the scores of auditory tests was investigated.
The results obtained were as follows: As could be expected, patients with slight tongue resections and who exhibited slight mandibular displacements at rest and during vertical jaw movement showed near normal linguapalatal contact and only minor distortions in articulation, while those with extensive tongue resections showed severely abnormal linguapalatal contact patterns and severe distortions in articulation. However, patients exhibiting abnormal mandibular movement, even though tongue resection may have been slight, also showed abnormal linguapalatal contact patterns and severe distortions in articulation. The types of abnormal mandibular movement in which these results occurred were: an abnormally large deviation of the mandible at the highest position, abnormally large horizontal deviation of the mandible during articulation, abnormally long distance or fast peak velocity of mandibular movement, and unusual horizontal deviation of the mandible at rest associated with oblique motion during linguapalatal contact. These results suggest that abnormal mandibular movement is one of the causes of articulation disorders follwing mandibulectomy and therefore preserving musculature and minimizing the formation of the scar tissue surrounding the remaining mandible may help to minimize acquired articulation disorders following mandibulectomy.