• The Journal of Korean society of community based occupational therapy
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• v.7 no.2
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• pp.1-8
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• 2017

Objectives : This study was conducted to investigate the activity of the supra and infrahyoid muscles according to the temperature and the amount of water in healthy adults. Methods : The amount of water was set to 3 mL and 20 mL, and the temperature was subdivided into $4^{\circ}C$, $22^{\circ}C$, and $40^{\circ}C$ in order to compare the activity of the supra and infrahyoid muscles in twenty-seven healthy adults. We used the mean value of the activity of the supra and infrahyoid muscles while they were swallowing saliva in order to set the reference voluntary contraction (%RVC). Results : Muscle activity was significantly increased when they swallowed 20 mL of water rather than 3 mL in the left infrahyoid muscles at $4^{\circ}C$, $22^{\circ}C$ and $40^{\circ}C$ (p=.00; p=.00; p=.00), the right infrahyoid muscles at $22^{\circ}C$and $40^{\circ}C$ (p=.01; p=.01), the left suprahyoid muscles at $4^{\circ}C$ (p=.03). Muscle activity of the right suprahyoid muscles was significantly decreased at $40^{\circ}C$ compared to $4^{\circ}C$ and $22^{\circ}C$ when they swallowed 20 mL of water (p=.04). Conclusion : In the future, other variables such as viscosity and taste should be considered, and further studies on patients with impaired nervous system as well as healthy subjects will be needed.

• Journal of Oral Medicine and Pain
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• v.40 no.3
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• pp.115-123
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• 2015

Purpose: The aim of this study was to elucidate the coordination patterns of the sternocleidomastoid and posterior cervical muscles in response to symmetrical and asymmetrical jaw functions in normal adults. Methods: Twenty-seven healthy volunteers (8 females, 19 males; mean age, $30.4{\pm}2.5$ years) participated in this study. Surface electromyography (EMG) was used to record activities in the masseter, suprahyoid, sternocleidomastoid, and posterior cervical muscles at rest and during maximum tooth clenching, biting of a cotton roll with the anterior teeth, unilateral biting of a cotton roll with the posterior teeth, bilateral biting of cotton rolls with the posterior teeth, and jaw opening while seated. Normalized amplitude, activity indices, and asymmetry indices were compared between the muscles and the jaw tasks. Results: During symmetrical jaw functions (e.g., tooth clenching, biting with the anterior teeth, bilateral biting with the posterior teeth, jaw opening), the sternocleidomastoid and posterior cervical muscles showed elevated EMG amplitudes compared with the resting condition. The co-activation pattern of the sternocleidomastoid muscle was more pronounced than those of the posterior cervical muscles during these tasks. During asymmetrical jaw functions (e.g., unilateral biting with the posterior teeth), the ipsilateral sternocleidomastoid and masseter muscles showed higher contraction activity than did the contralateral muscles, but the contralateral posterior cervical muscles were more active than the ipsilateral muscles. Conclusions: The sternocleidomastoid and posterior cervical muscles were shown to be co-activated and coordinated anteroposteriorly or bilaterally according to symmetrical or asymmetrical jaw function. These results suggest an integrated neural control mechanism for the jaw and neck muscles, and provide further evidence supporting the intimate functional coupling between the trigeminal and cervical neuromuscular systems.

• The korean journal of orthodontics
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• v.24 no.1 s.44
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• pp.199-220
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• 1994

This study was conducted to determine the electromyographic features in the perioral muscles of class II division 1 malocclusion with incompetent lips, and to grope the correlation between its activities and craniofacial morphology. Tn this study, 14 subjects with class II division 1 malocclusion with incompetent lips(mean age of 20.5 years) and 20 subjects with normal occlusion(mean age of 23.9 years) were investigated. Electromyographic data were recorded from orbicularis oris, mentalis, buccinator and suprahyoid muscles durig rest lip posture, lip position at sealing, maximum sealing, maximal blowing, maximal biting, sipping milk, sipping and swallowing milk, chewing gum, masticating almond, swallowing almond and phonation utilizing the Medelec MS-25 electromyographic apparatus. Lateral cephalometric radiographs were taken with the mandible in intercuspal position on all subjects. All data were recorded statistically processed. The findings of this study can be summerized as follows : 1. In class II division 1 malocclusion with incompetent lips, the overall augmentations of perioral muscle activities during various functionel movements set for lip sealing were manifested and particular swelling in mentalis activity at rest was detected. 2. On the other hand remarkable diminution of upper lip acitivities at lip sealing movements was drawn. 3. In Class II division 1 malocclusion with incompetent lips, negative correlations existed between the diversity of upper lip activities and upper incisor position and overjet as well in contrast to positive correlations in the lower lip. 4. It was suggested that the abnormal function of lower lip and mentalis muscle contributed somewhat the revelation of the characteristics of Class II division 1 malocclusion.

• Journal of Medicine and Life Science
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• v.15 no.1
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• pp.12-15
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• 2018

Digastric and stylohyoid muscles are located in the suprahyoid region. There have been few studies about the general morphology of stylohyoid muscle and its relationship with digastric muscle. During routine educational dissection, unusual insertion of bilateral stylohyoid muscle was found in the cadaver of a 92-year-old Korean male, whose cause of death was 'aspiration pneumonia'. Stylohyoid muscle arose from the styloid process, and inserted onto the intermediate tendon of digastric muscle and the hyoid bone on both sides. Each digastric muscle normally consists of an anterior belly, intermediate tendon and a posterior belly. In this cadaver, there were two anterior bellies on right side while one anterior belly was found on left side. Stylohyoid muscle ran medial to the intermediate tendon of digastric muscle on both sides. The anatomical relationship between stylohyoid and digastric muscles was reviewed based on morphological and embryological point of view.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.5 no.1
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• pp.11-21
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• 1994

The vocal pitch is controlled by the tension, mass, and length of the vocal fold. It is well known that cricothyroid approximation raises the vocal pitch by simulating the contraction of the cricothyroid muscle, and there were so many reports that have noted a relationship between cricothyroid distance and pitch control, but there does not seem to be any single generally accepted theory to account for this connection. It is generally known that the strap muscles are active during low and falling Fo, and the suprahyoid muscles are active during high and raising Fo. These findings can be related to a general picture of the motion of the larynx during changes in Fo, the cricothyroid joint would tend to lengthen the vocal folds, as the larynx moves up and forward, and relax them as it moves back and down. In this study, we suggest that the relationship between anterior cricothyroid distance and fundamental frequency of the larynx was so complex according to the level of larynx and vertebral curvature. The higher the level of larynx, the wider the cricothyoid distance, but there is more greater fundamental frequency even though more wide cricothyroid distance. This phono-menon seems to be due to the multifactors, especially the vertical tension of the conus elasticus or the change of cricothyroid articulation. It is generally known that the crocothyoid and vocal is muscles are very closely related to pitch elevation, but sternohyoid muscle seems to be more closely related to pitch lowering. By this electromyographic studies, the sternohyoid muscle have dual activity to pitch control, increased activity during the low fundamental frequency and falling pitch, but also increased activity during the higher fundamental frequency and raising pitch at least in this study.

• Korean Journal of Bronchoesophagology
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• v.13 no.2
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• pp.9-16
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• 2007

Cricopharyngeal dysphagia(CPD), a common condition in the dysphagic patient, refers to the dysfunction of the upper esophageal sphincter complex(UESC), which is composed of the cricopharyngeus, inferior pharyngeal constrictor and the upper segment of the cervical esophagus. Primary CPD is the disease entity solely confined to dysfunctional UESC, while secondary CPD encompasses various conditions that accompany UESC dysfunction. For proper diagnosis and treatment of such entity, a thorough understanding of the complex anatomy and physiology of the upper esophageal sphincter. Adequate relaxation of the cricopharyngeal muscle in conjunction with anterosuperior excursion of the larynx by suprahyoid muscles and propulsion of food bolus are prerequisite for normal swallow, mechanisms of which if altered result in cricopharyngeal dysfunction. Of the various methods used for the diagnosis of cricopharyngeal dysphagia, videofluoroscopy remains the method of choice. Mechanical dilatation of the cricopharayngeus, cricopharyngeal myotomy and botulinum toxin injection and head-lift exercise have been used in clinical practice to relieve dysphagia in such patients. Such procedures have therapeutic effect in primary CPD, but so often fail to relieve swallowing dysfunction in patient with secondary CPD. We herein explain ancillary procedures that support these primary treatment options, which lead to successful treatment of dysphagia.

• The korean journal of orthodontics
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• v.42 no.6
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• pp.318-328
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• 2012

Objective: To assess the position and movements of the hyoid bone during deglutition in patients with open bite. Methods: Thirty-six subjects were divided into 2 groups according to the presence of anterior open bite. The open bite group (OBG) and control group each comprised 18 patients with a mean overbite of $-4.9{\pm}1.9$ mm and $1.9{\pm}0.7$ mm. The position of the hyoid bone during the 4 stages of deglutition was evaluated by measuring vertical and horizontal movement of the bone. Results: Interactions of group and stage showed no significant effect on the measurements (p > 0.05). However, when group and stage were evaluated individually, they showed significant effects on the measurements (p < 0.001). In OBG, the hyoid bone was more inferiorly and posteriorly positioned, and this position continued during the deglutition stages. Conclusions: The hyoid bone reaches the maximum anterior position at the oral stage and maximum superior position at the pharyngeal stage during deglutition. Open bite does not change the displacement pattern of the bone during deglutition. The hyoid bone is positioned more inferiorly and posteriorly in patients with open bite because of released tension on the suprahyoid muscles.

• Journal of the Ergonomics Society of Korea
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• v.32 no.6
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• pp.541-547
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• 2013

Objective: The aim of this study is to find the influence on muscle fatigue by changing an angle of neck while Shaker exercise. Background: Shaker exercise is commonly applied to dysphagia patients for strengthen suprahyoid muscle(SHM) and relaxing upper esophageal sphincter. Method: Experiments were conducted by measuring muscle fatigue with surface electromyography(SEMG) in case of neck $15^{\circ}$ and $50^{\circ}$ flexion, in addition to original method. For the study 30 undergraduate students were participated as subjects. Muscle fatigue was measured with variations of median frequency(MF) and median frequency slope(MFS) by attaching SEMG to 3 muscles. At the same time, perceived exertion was measured by using Borg's rating of perceived exertion(RPE). Results: A MF was increased when low angle in SHM, both male and female. It means that muscle fatigue was significantly decreased(p<.05). RPE was significantly increased when low angle(p<.01). Perceived exertion explained 15.2% of the variation of MF in SHM. And regression equation was, MF in SHM = 59.918 + (4,910 * RPE). Conclusion: The outcome shows that it is possible to use the efficient method which makes muscle fatigue decrease by reducing the angle of neck flexion. Application: The results might contribute to develop the effective Shaker exercise method.

• Anatomy and Cell Biology
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• v.56 no.4
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• pp.441-447
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• 2023

One of the suprahyoid muscles is the digastric muscle which comprises anterior and posterior bellies joined by an intermediate tendon. Because of its close relationship with the submandibular gland, lymph nodes, and chief vessels of the neck, detailed knowledge about the morphometry of the digastric muscle is essential. The objective of the current cross-sectional evaluative study is to record morphometry along with the digastric muscle's origin, insertion, and variability. Forty human cadavers (25 males and 15 females) were dissected, and the head and neck regions were studied in detail. The attachment of the digastric muscle anterior belly to the digastric fossa of the mandible was noted, and the distal attachment of the posterior belly to the mastoid notch was traced. The length of the anterior belly from the digastric fossa to its intermediate tendon and the length of the posterior belly from the intermediate tendon to its mastoid attachment were measured. There is a fair correlation between the length of the neck and the length of the anterior and posterior belly. The study also identified two cases of bilateral accessory bellies of the anterior belly of the digastric. Normal morphometric data is provided by this study on details of the digastric muscle. It is significant from a clinical and surgical point of view as the muscle lies in proximity to the important structures of the neck.