Measurement of Maximum Tongue Protrusion Force (MTPF) In Healthy Normal Adults

Abstract

Genioglossus (GG) is the primary lingual muscle responsible for tongue protrusion, which is important for speech, swallow and breathing. Contraction of the GG plays an important role in maintaining upper airway patency, preventing posterior tongue displacement and upper airway closure. GG electromyogram studies report GG tongue muscle activity increases with increased negative pressure in the upper airway. We propose that tongue protrusive strength and tone may be related to upper airway patency, and when protrusive strength is reduced, individuals are at higher risk of developing sleep apnea, or speech/swallow disorders. However, in order to test that hypothesis, it is necessary to determine a normal range for tongue protrusion strength. We designed a device to indirectly measure GG strength by measuring tongue protrusion force. The device is a piston in a cylinder with a force transducer at the base of the piston. The cylinder is held by the front teeth, and the tongue extends 0.5–1 cm beyond the teeth to touch the piston. The goal of the current study was to determine normative values of maximum tongue protrusion force (MTPF) in healthy young adults, using the new device. We hypothesized that MTPF would be greater in males than females. One hundred and one healthy adults (male: 23, female: 78) participated in this study. Inclusion criteria were age 18 or above, no self‐reported history of mouth or tongue disease/surgery, and no self‐reported sleep apnea. Their self‐reported sex, age, and smoking history were recorded; height and weight were measured. The subjects pushed their tongue forward against the device's piston (protrusion) as hard as possible for 2–5 seconds and MTPF was recorded in Newtons (N). Subjects performed 5–10 MTPF efforts. The MTPF for all efforts were averaged for each subject. All subjects were able to perform the MTPF task and no adverse responses were reported. The average MTPF for all subjects was 15.4 N (SD ± 3.8), with a range of 8–29. The male average MTPF was higher than female (17.8 N, SD ± 3.7 versus 14.7 N, SD ± 3.5; p = .001). There was no significant difference for age between males and females; males had significantly greater height and weight. The results demonstrate our novel device can effectively measure tongue protrusive force in health young adults. As well, this study provides normative values for MTPF, and identified significant tongue protrusion strength differences between males and females.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.