Do subjects with forced lip closure have different perioral and jaw muscles activity?

Objective: To evaluate the activity of mentalis (MN), buccinator (BC), and suprahyoid (SH) muscles among participants with different lip competence..Methods: Sixty-three participants were classified clinically and assigned to the following groups of 21 each: 1) competent lips (competent), 2) incompetent lips (incompetent), or 3) forced lip closure (forced). Activity was recorded at rest, swallowing, speaking, reciprocal compression of the lips, and chewing.Results: MN activity in incompetent was significantly higher than competent at rest, and it was significantly higher in incompetent and forced when compared with competent during swallowing (p< .05). No differences among incompetent and forced were observed (p> .05). During speaking, reciprocal compression of the lips, and chewing, MN activity did not show significant differences among groups. BC and SH activity did not show significant differences (p> .05).Conclusion: MN activity during swallowing can be considered a relevant biomarker to differentiate between forced and competent participants.

Effect of laterotrusive occlusal scheme on chewing duration, external intercostal muscular activity, heart rate, and oxygen saturation.

Objective: To evaluate the effect of the laterotrusive occlusal scheme on chewing duration, external intercostal (EIC) electromyographic (EMG) activity, heart rate (HR), and oxygen saturation (OS) during different tasks in the upright seated position.Methods: Fifty young participants, 25 with canine guidance and 25 with group function, were included. Chewing duration, bilateral EIC EMG activity, HR, and OS were recorded during the following tasks: 1) chewing until swallowing threshold; 2) laterotrusive teeth grinding.Results: Chewing duration, bilateral EIC EMG activity, HR, and OS showed no significant differences between the two laterotrusive occlusal schemes during the tasks studied.Conclusion: These results suggest that chewing duration, EIC muscle activity, HR, and OS were not significantly influenced by the laterotrusive occlusal scheme. Therefore, when a modification of the laterotrusive occlusal scheme is needed during oral rehabilitation or orthodontic treatment, canine guidance or group function should not significantly change EMG activity of EIC muscles.

Electromyographic Comparison of Lips and Jaw Muscles between Children With Competent and Incompetent Lips: A Cross Sectional Study.

OBJECTIVE: This cross-sectional study evaluates the electromyographic (EMG) activity of lips and anterior temporalis muscles of children with competent or incompetent lips. STUDY DESIGN: Forty children were classified clinically according to their lip competence into two groups of 20 each: 1) competent lips group (CLG), and 2) incompetent lips group (ILG). Surface EMG activity of the superior orbicularis oris (SOO), inferior orbicularis oris (IOO), and anterior temporalis (AT) muscles was recorded with the children seated in the upright position during the following tasks: 1) at rest; 2) speaking; 3) swallowing; 4) puffing out the cheeks. RESULTS: ILG showed lower EMG activity than CLG in the SOO and IOO muscles at rest, similar activity in both muscles during speaking, similar activity in the SOO muscle and lower in the IOO during swallowing. ILG showed significantly higher activity than CLG in both muscles while puffing out the cheeks. In the AT muscle, ILG showed lower activity than CLG at rest, during speaking and swallowing, whereas activity was similar while puffing out the cheeks. CONCLUSION: The difference in EMG activity recorded in children with incompetent lips and with competent lips suggests that the status of their musculature could affect the position and stability of their upper/lower anterior teeth.

Awake teeth grinding in participants with canine guidance or group function: Effect on diaphragm EMG activity, heart rate, and oxygen saturation.

Objective: To compare the effect of canine guidance or group function on diaphragm activity, heart rate, and oxygen saturation during awake teeth grinding at different body positions. Methods: Fifty healthy participants, 25 with canine guidance and 25 with group function, were included. Bilateral electromyographic (EMG) recordings of the diaphragm (DIA) during awake teeth grinding were performed in standing, seated upright, and right lateral decubitus positions. Simultaneously, heart rate and oxygen saturation were measured. Results: EMG activity of the DIA muscle was similar in the working side and non-working side between participants with canine guidance and group function in the different body positions studied. The heart rate and oxygen saturation showed no significant differences between the two groups. Conclusion: EMG activity of the DIA muscle, the heart rate, and oxygen saturation during teeth grinding are not significantly influenced by the type of laterotrusive occlusal scheme.

Effect of breathing type on electromyographic activity of respiratory muscles during tooth clenching at different decubitus positions.

OBJECTIVE: To compare the effect of breathing type on electromyographic (EMG) activity of respiratory muscles during tooth clenching at different decubitus positions. METHODS: Forty young men participants were included, 11 with upper costal, 9 with mixed, and 20 with costo-diaphragmatic breathing type. EMG recordings of diaphragm (DIA), external intercostal (EIC), sternocleidomastoid (SCM), and latissimus dorsi (LAT) muscles during tooth clenching in the intercuspal position were performed in dorsal, left lateral, and ventral decubitus positions. RESULTS: DIA EMG activity was higher in subjects with upper costal or mixed than with costodiaphragmatic breathing type (p = 0.006; 0.021, respectively), whereas it was similar between upper costal and mixed breathing types. EIC, SCM, and LAT activity was similar among breathing types. CONCLUSION: Higher DIA activity would be a risk factor to exceed the adaptive capability of healthy subjects with upper costal or mixed breathing type.

Comparison of muscle activity between subjects with or without lip competence: Electromyographic activity of lips, supra- and infrahyoid muscles.

AIM: This study compares the electromyographic (EMG) activity of the muscles from the lips and hyoid bone in subjects with or without lip competence. METHODOLOGY: Two groups of 20 subjects each, with or without lip competence were studied. EMG activity of the superior orbicularis oris (SOO), inferior orbicularis oris (IOO), suprahyoid (SH) and infrahyoid (IH) muscles was recorded with the subject seated in the upright position during the following tasks: (1) at rest; (2) speaking; (3) swallowing; (4) forced deep breathing; (5) maximal voluntary clenching; and (6) chewing. RESULTS: EMG activity was significantly higher in subjects without competent lips than with competent lips in the SOO and IOO muscles during tasks 3 and 4, SOO during task 2 and IOO during task 6. EMG activity was similar in the SOO and IOO muscles during tasks 1 and 5, SOO during task 6 and IOO during task 2. Activity of the SH and IH muscles was similar in both groups for all tasks. CONCLUSIONS: Higher activity in subjects without competent lips implies a higher muscular effort due to the requirement of lip sealing during functional activities. Hyoid muscular activity was not modified by the presence or absence of lip competence.