• Physical Therapy Korea
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• v.26 no.3
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• pp.76-83
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• 2019

Background: The hyoid bone is the only non-jointed structure among the skeletal tissues of the head and neck region, and its movement and posture depend on the attached muscle, ligament, and fascia. The location of the hyoid bone is important for airway maintenance, vocalization, chewing, swallowing, breathing, and head and scapular position. In general, the location of the hyoid bone is measured using radiographs and 3D computed tomography, and no studies have reported on clinical measurement methods. Objects: This study was performed to suggest clinical measurement methods for lateral deviation of the hyoid bone and to evaluate their reliability. Methods: In this study, 24 healthy volunteers (12 males, 12 females) in Cheongju-si participated. Two examiners performed the center point test and lateral motion test twice each to measure the lateral displacement of the hyoid bone. The reliability of the center point test was analyzed using intra-class correlation coefficients (ICC), and the reliability of the lateral motion test was analyzed using Cohen's kappa coefficient. Results: The intra-rater reliability of the center point test was good, and the inter-rater reliability was moderate. The intra- and inter-rater reliability of the lateral motion test showed substantial reliability. Conclusion: Based on these results, the center point test and the lateral motion test can be used as an alternative methods of the measurement of lateral deviation of the hyoid bone for people who have musculoskeletal disorders of the head, neck, and scapula.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.3
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• pp.564-571
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• 1999

The importance of the hyoid bone lies in its unique anatomic relationships. It has no bony articulations but provides attachment for muscles, ligaments, and fascia of the pharynx, mandible, and cranium. Various studies have documented a variability of hyoid bone position in relation to changed mandibular position or head posture. The aim of this study is to investigate the hyoid bone position and inclination on cephalometric radiographs of three groups of patients exhibiting Class I, II, and III malocclusions. The conclusions obtained from this study can be summarized as follows ; 1. Class III malocclusion patients show a more anterior position of the hyoid bone and also less steep inclination of the hyoid bone. 2. The anteroposterior position of the hyoid bone relative to the cervical vertebra and mandible was very constant. 3. The hyoid bone represented the anterior bony boundary of the pharynx at a lower level than PNS.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.827-839
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• 1994

This study was conducted to assess the positional changes of hyoid bone following the use of activator in Angles class III malocclusion patients with functional factors. For this study, 40 Angle's class I patients and 40 Angle's class III patients, totally 80 subjects were used. They are all in Hellman's dental age IIIB-IIIC ranges. In lateral cephalogram to compare Angle's class I group and Angle's class III group, and the positional changes of the hyoid bone before and after the use of activator in Angle's class III malocclusion group. The results were obtained as follows; 1. Comparison of Angle's class I group and Angle's class III group. In comparison to Angle's class I group, hyoid bone is more anteriorly and superiorly positioned in Angle's class III group. The hyoid bone showed reverse inclination to the mandibular plane in Angle's class III malocclusion group. 2. Comparison of the hyoid positional change before and after use of Activator in Angle's class III malocclusion group. The hyoid bone is displaced posteriorly and inferiorly in vertical relationship. The hyoid bone also showed counter-clockwise rotation. 3. No statistical difference was found between after Activator use data of Angle's class m malocclusion group and Angle's class I group. It is concluded that the hyoid bone in Angle's class III malocclusion group changed its position, similar to Angle's class I malocclusion group.

• Journal of the Ergonomics Society of Korea
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• v.29 no.3
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• pp.331-336
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• 2010

The purpose of this study was to identify the effect of the craniocervical posture on swallowing and hyoid bone movement with sitting posture in wheelchair, and to provide basic data for developing a treatment program for dysphagia. A total of sixty healthy adults without a history of dysphagia who were guardians or care assistants of inpatients at Hospital K underwent video fluoroscopy performed by physiatrists from April to July 2009. The results of the fluoroscopy were analyzed based on the measurement of hyoid bone movements. The hyoid bone movement(horizontal, vertical, and diagonal) was significantly high in the neutral craniocervical, chin-tuck, and sixty degrees extension postures, in descending order(p<.05). It was found that the neutral craniocervical posture is the most effective posture for hyoid bone movement with sitting posture in wheelchair.

• The Journal of the Korean dental association
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• v.13 no.10
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• pp.941-946
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• 1975

치과교정학 분야에 있어서 부정교합자의 다양한 하악골 위치변화에 따른 Hyoid bone 위치변화에 대한 연구는 부족한 감이 있어, 저자등은 Hellman의 치령ⅢA 이후의 부정교합을 가진 남ㆍ녀 97명을 Angle씨 각급 부정교합의 분류에 의해 중심교합위와 안정위시의 두부 X선 사진을 가각 탐득하고 Hyoid bone의 위치변화를 측정하여 다름과 같이 결과를 얻었다. 1. 중심교합위에서의 Cranial base에 대한 Hyoid bone 위치변화에서는 Angle씨 ClassⅢ에서 남ㆍ녀 모두 물징적으로 전방에 위치하며, Mandibular plane에 대한 Hyoid bone위치변화에서는 각급 부정교합사이에 특기할 차이가 없다. 2. 안정위에서의 Hyoid bone위치는 중심교합위에서의 위치와 비슷한 분포를 나타내고 있다. 3. 중심교합위에서는 안정위로싀 위치변화에서 각급 부정교합 똑같이 후ㆍ하방 이동을 나타내고 있다.

• Archives of Plastic Surgery
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• v.38 no.2
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• pp.199-202
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• 2011

Purpose: Hyoid bone is a U-shaped bone in the anterior of the neck. Hyoid bone fractures are exceedingly rare and represent only 0.002% of all fractures because of its protective position relative to the mandible and its suspension by elastic musculature. We report a patient who presented hyoid bone fracture associated with hypoglossal nerve palsy. We also discuss the possible complication and treatment. Methods: A 69-year-old man was transferred from another institution because of persistent purulent discharge from the left chin. He had a history of trauma in which a knuckle crane grabbed his face and neck in the construction site. A CT scan at the time of the accident demonstrated a comminuted fracture of the right side of the mandible and hyoid bone fracture at the junction between body and right greater cornua. The displaced fracture of hyoid bone and fullness in the pre-epiglottic space were noted, probably indicating some edema. The patient was transferred into ICU after treatment of emergency tracheostomy because the patient showed respiratory distress rapidly. When the patient was hospitalized in our emergency room, he complained of dysphagia and pain when swallowing. On examination of oral cavity, the presence of muscle wasting with fasciculation of the tongue was noted and the tongue deviates to the left side on protruding from the mouth. Pharyngolarygoscopy was performed to make sure that there was no evidence of progressive swelling and pharyngeal laceration. Results: The patient underwent surgical removal of dead and infected tissue from the wound and reconstruction of mandibular bony defect by iliac bone grafting. Hyoid bone fracture was managed conservatively with oral analgesics, soft diet and restricted movement. Hypoglossal nerve palsy was resolved within 7 weeks after trauma without complications. Conclusion: Closed hyoid bone fracture is usually uncomplicated and thus it can be treated conservatively. Surgical intervention for hyoid bone fracture is recommended for patient with airway compromise, pharyngeal perforation and painful symptoms which show no response to conservative care. Furthermore, since respiratory distress syndrome may develop quickly, close observation is required. Besides, hypoglossal nerve palsy is a rarely recognized complication of hyoid bone fracture.

• 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 Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.5
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• pp.224-231
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• 2015

Objectives: The purpose of this study was to evaluate changes in the pharyngeal airway space and hyoid bone position after mandibular setback surgery with bilateral sagittal split ramus osteotomy (BSSRO) and to analyze the correlation between the amount of mandibular setback and the amount of change in pharyngeal airway space or hyoid bone position. Materials and Methods: From January 2010 to February 2013, a total of 30 patients who were diagnosed with skeletal class III malocclusion and underwent the same surgery (BSSRO) and fixation method in the Division of Oral and Maxillofacial Surgery, Department of Dentistry at the Ajou University School of Medicine (Suwon, Korea) were included in this study. Lateral cephalograms of the 30 patients were assessed preoperatively (T1), immediately postoperatively (T2), and 6 months postoperatively (T3) to investigate the significance of changes by time and the correlation between the amount of mandibular setback and the amount of change in the airway space and hyoid bone position. Results: Three regions of the nasopharynx, oropharynx, and hypopharynx were measured and only the oropharynx showed a statistically significant decrease (P<0.01). A significant posterior and inferior displacement of the hyoid bone was found 6 months after surgery (P<0.01). Analysis of the correlation between the amount of mandibular setback and the amount of final change in the airway space and hyoid bone position with Pearson's correlation showed no significant correlation. Conclusion: In this study, the oropharynx significantly decreased after mandibular setback surgery, and changes in the surrounding structures were identified through posteroinferior movement of the hyoid bone during long-term follow-up. Therefore, postoperative obstructive sleep apnea should be considered in patients who plan to undergo mandibular setback surgery, and necessary modifications to the treatment plan should also be considered.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.27.1-27.9
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• 2020

Background: Mandibular setback surgery can change the position of the mandible which improves occlusion and facial profile. Surgical movement of the mandible affects the base of the tongue, hyoid bone, and associated tissues, resulting in changes in the pharyngeal airway space. The aim of this study was to analyze the 3-dimensional (3D) changes in the hyoid bone and tongue positions and oropharyngeal airway space after mandibular setback surgery. Methods: A total of 30 pairs of cone-beam computed tomography (CBCT) images taken before and 1 month after surgery were analyzed by measuring changes in the hyoid bone and tongue positions and oropharyngeal airway space. The CBCT images were reoriented using InVivo 5.3 software (Anatomage, San Jose, USA) and landmarks were assigned to establish coordinates in a three-dimensional plane. The mean age of the patients was 21.7 years and the mean amount of mandibular setback was 5.94 mm measured from the B-point. Results: The hyoid bone showed significant posterior and inferior displacement (P < 0.001, P < 0.001, respectively). Significant superior and posterior movements of the tongue were observed (P < 0.05, P < 0.05, respectively). Regarding the velopharyngeal and glossopharyngeal spaces, there were significant reductions in the volume and minimal cross-sectional area (P < 0.001). The anteroposterior and transverse widths of the minimal cross-sectional area were decreased (P < 0.001, P < 0.001, respectively). In addition, the amount of mandibular setback positively correlated with the amount of posterior and inferior movement of the hyoid bone (P < 0.05, P < 0.05, respectively). Conclusion: There were significant changes in the hyoid bone, tongue, and airway space after mandibular setback surgery.

• Journal of Yeungnam Medical Science
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• v.5 no.2
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• pp.71-77
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• 1988

This study was made to investigate the influence of mouth breathing to tongue, mandible and hyoid bone position. It has been clinically suggested that the mouth breathing is induced by the respiratory dysfunction of nasopharyngeal airway causing by the Adenoids. The author used the 50 children, who were the nasal breathes with normal occlusion as the control group, and 50 children, who were mouth breathers with Adenoid as the experimental group. Results were as following: 1. In experimental group, the tongue was positioned more anterior and lower than that of the normal children. 2. In experimental group, the mandible was positioned more lower than that of the normal children. 3. In experimental group, the hyoid bone was positioned more anterior and lower than that of the normal children.