Clarification of the aspects of tongue‐palate contacts during mastication with/without stage II transport

Background During mastication, the tongue presses bolus into pharynx by a "squeeze-back" motion, known as stage II transport (St2Tr). However, pressure of St2Tr tongue-palate contact has not been examined. Objectives We aimed to clarify aspects occurrence and during mastication measuring pressure. Methods Ten healthy adults (eight men, two women, aged 26.8 ± 2.2 years) were enrolled. Tongue was measured (Swallow Scan) mastication. Sensors placed on palate near incisive papilla (Ch.1), in middle (Ch.2), at posterior (Ch.3), first molars habitual (Ch.H) non-habitual (Ch.Nh) masticatory sides. Nasopharyngeal endoscopy confirmed swallowing. pressures repeatedly, from onset through swallow, until eight sets data obtained. Tongue-palate frequencies, integrated values pressure, times recorded for St2Tr(+) St2Tr(−) conditions. Results occurred 43 80 trials (53.8%). exhibited highest frequency Ch.H; it higher frequencies Ch.2, Ch.3 Ch.H than St2Tr(−). Ch.1, Ch.2 Ch.3; Ch.1 Conclusion The study suggested that St2Tr, frequently touched central regions, well its side. It applies strongest anterior pharynx.