• The korean journal of orthodontics
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• v.39 no.2
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• pp.72-82
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• 2009

Objective: The purpose of this study was to investigate the structural changes of the hyoid bone and upper airway after orthognathic surgery for skeletal class III anterior open bite patients, and make comparisons with normal occlusion. Methods: Pre- and post-operative computed tomography (CT) examinations were performed on 12 skeletal class III anterior open bite patients who were treated with mandibular setback osteotomy. Using the V-works $4.0^{TM}$ program, 3-dimensional images of the total skull, mandible, hyoid bone, and upper airway were evaluated. Results: In the Class III open bite group, the hyoid bone were all positioned anteriorly, compared to the Normal group (p < 0.05). The angle between the hyoid plane and mandibular plane in the Class III openbite group before surgery was greater than in the Normal group (p < 0.05), and the difference increased after surgery (p < 0.01). In the Class III openbite group, the volume of the upper airway decreased after surgery (p < 0.001) and the volume of the upper airway was smaller than the Normal group before and after surgery (p < 0.001). Conclusions: The narrow upper airway space in skeletal Class III openbite patients decreased after mandibular setback osteotomy. This may affect the post-surgical stability.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.38-47
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• 2019

The most common cause of mouth breathing is obstacles caused by mechanical factors in upper airway. Mouth breathing could be consequently pathological cause of sleep-disordered breathing. Sleep-disordered breathing in children can cause growth disorders and behavioral disorders. The purpose of this study was to investigate relationship between upper airway and sleep-disordered breathing in children with mouth breathing. Twenty boys between 7 - 9 years old who reported to have mouth breathing in questionnaire were evaluated with clinical examination, questionnaires, lateral cephalometric radiographs, and portable sleep testing. This study assessed apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) for the evaluation of sleep-disordered breathing and was done to investigate the correlation between these values and the upper airway width measured by lateral cephalometric radiographs. There was no significant correlation with the size of the tonsils (p = 0.921), but the adenoid hypertrophy was higher in the abnormal group than in the normal group (p = 0.008). In the classification according to AHI and ODI, retropalatal and retroglossal distance showed a statistically significant decrease in the abnormal group compared to the normal group (p = 0.002, p = 0.001). As AHI and ODI increased, upper airway width tended to be narrower. This indicates that mouth breathing could affect the upper airway, which is related to sleep quality.

• Journal of Genetic Medicine
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• v.15 no.1
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• pp.34-37
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• 2018

A 1q21.1 microdeletion is an extremely rare chromosomal abnormality that results in phenotypic diversity and incomplete penetrance. Patients with a 1q21.1 microdeletion exhibit neurological-psychiatric problems, microcephaly, epilepsy, facial dysmorphism, cataract, and thrombocytopenia absent radius syndrome. We reported a neonate with confirmed intrauterine growth restriction (IUGR), micrognathia, glossoptosis, upper airway obstruction, facial dysmorphism, and eye abnormality at birth as well as developmental delay at the age of 1 year. These clinical manifestations, except for the IUGR and upper airway obstruction, in the neonate indicated a 1q21.1 microdeletion. Here, we report a rare case of a 1q21.1 microdeletion obtained via paternal inheritance in a newborn with upper airway obstruction caused by glossoptosis and tracheal stenosis.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.105-115
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• 2020

Purpose: This study investigated the position of the hyoid bone and its relationship with airway dimensions in different skeletal malocclusion classes using cone-beam computed tomography (CBCT). Materials and Methods: CBCT scans of 180 participants were categorized based on the A point-nasion-B point angle into class I, class II, and class III malocclusions. Eight linear and 2 angular hyoid parameters(H-C3, H-EB, H-PNS, H-Me, H-X, H-Y, H-[C3-Me], C3-Me, H-S-Ba, and H-N-S) were measured. A 3-dimensional airway model was designed to measure the minimum cross-sectional area, volume, and total and upper airway length. The mean crosssectional area, morphology, and location of the airway were also evaluated. Data were analyzed using analysis of variance and the Pearson correlation test, with P values <0.05 indicating statistical significance. Results: The mean airway volume differed significantly among the malocclusion classes(P<0.05). The smallest and largest volumes were noted in class II (2107.8±844.7 ㎣) and class III (2826.6±2505.3 ㎣), respectively. The means of most hyoid parameters (C3-Me, C3-H, H-Eb, H-Me, H-S-Ba, H-N-S, and H-PNS) differed significantly among the malocclusion classes. In all classes, H-Eb was correlated with the minimum cross-sectional area and airway morphology, and H-PNS was correlated with total airway length. A significant correlation was also noted between H-Y and total airway length in class II and III malocclusions and between H-Y and upper airway length in class I malocclusions. Conclusion: The position of the hyoid bone was associated with airway dimensions and should be considered during orthognathic surgery due to the risk of airway obstruction.

• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.43-52
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• 1996

The purpose of this study was to compare and evaluate the upper airway structure between the snorers and asymptomatic control subjects depending on the positional change. Lateral cephalograms in the upright and supine position were taken in 25 female snorers and 20 female asymptomatic control subjects. The length and the area of the soft palate, tongue and airway were measured and evaluated statistically. The results obtained were as follows : 1. The snorers showed longer and higher tongue, narrower and longer airway, inferiorly positioned hyoid bone, longer and broader soft palate and narrower hypopharynx than the control subjects both in the upright and supine position. In addition, the snorers showed broader tongue area and narrower oropharynx area than the control subjects in supine position. 2. Depending on the positional change from upright to supine position, the controls and the snorers showed decreased airway length and superior positioned the hyoid bone. In addition, the snorers showed decreased tongue length and height, airway length and thickness and oropharynx area, but increased tongue area and soft palate area.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1979.05a
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• pp.8.2-8
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• 1979

Acute obstruction of the upper airway from trachea, a foreign body or Iaryngospasm may lead to death in a few minutes. The immediate restoration of an adequate airway in these patients may be lifesaving. Spontaneous respiration by means of a needle inserted into the trachea was studied in 21 rabbits using 16, 18, and 20 gauge extrcatheters. The results are as follows; 1) Airway resistance was markedly increased in all experimental animals. consequently tidal volume was also significantly decreased, but this seems to be compensatory by increased of respiratory frequency in l6G group. 2) Blood gas analysis revealed adequate pulmonary ventilation through the constricted airway (about 1/3 of normal sized trachea) during 60 minutes. In the other hand, hypercarbia, hypoxemia, and metabolic acidosis were developed in the group with severe constriction of the upper airway (about 1/4-1/6 of normal sized trachea). 3) The further study is postulated to confirm the the possibility of application of needle trcheostomy in man, but the rabbits were tolerable to the constricted airway with a small sized needle (l6G) into the trachea for 60 minutes.

• The korean journal of orthodontics
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• v.40 no.2
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• pp.66-76
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• 2010

Objective: Obstructive sleep apnea (OSA) is a common disorder which is characterized by a recurrence of entire or partial collapse of the pharyngeal airway during sleep. A given tidal volume must traverse the soft tissue tube structure of the upper airway, so the tendency for airway obstruction is influenced by the geometries of the duct and characteristics of the airflow in respect to fluid dynamics. Methods: Individualized 3D FEA models were reconstructed from pretreatment computerized tomogram images of three patients with obstructive sleep apnea. 3D computational fluid dynamics analysis was used to observe the effect of airway geometry on the flow velocity, negative pressure and pressure drop in the upper airway at an inspiration flow rate of 170, 200, and 230 ml/s per nostril. Results: In all 3 models, large airflow velocity and negative pressure were observed around the section of minimum area (SMA), the region which narrows around the velopharynx and oropharynx. The bigger the Out-A (outlet area)/ SMA-A (SMA area) ratio, the greater was the change in airflow velocity and negative pressure. Conclusions: Pressure drop meaning the difference between highest pressure at nostril and lowest pressure at SMA, is a good indicator for upper airway resistance which increased more as the airflow volume was increased.

• The korean journal of orthodontics
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• v.40 no.3
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• pp.134-144
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• 2010

Objective: The aim of this study was to evaluate the volumes and areas of the upper airways in children with Class II malocclusion, using three dimensional cone-beam computed tomography (CBCT) and to compare the volumetric and cross-sectional measurements and cephalometric variables to investigate possible relationships between the upper airway and facial morphology. Methods: CBCT scans were obtained from 37 subjects (17 boys and 20 girls; average age, 11.02 years). The upper airway volumes and areas were measured, and compared with cephalometric variables. Results: The area of the PNS-posterior plane ($S_{PP}$) was significantly smaller in the Class II malocclusion group (p < 0.05). Also, the volumetric and cross-sectional measurements were lower in Class II than in Class I malocclusion groups, although the differences were not significant between the two groups (p > 0.05). The Class II malocclusion group showed significantly smaller values of PFH, mandibular body length, pog to N perp and showed larger values of FMA, ANB, and facial convexity than the Class I malocclusion group. The volume of the upper airway in front of PNS point (WN) showed negative correlation with ANB (p < 0.05). Conclusions: The Class II malocclusion group had a narrower upper airway associated with a decreased posterior facial height and a divergent growth pattern than the Class I malocclusion group.

• Journal of the Korean Society of Visualization
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• v.19 no.3
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• pp.115-122
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• 2021

Oral cancer surgery typically consists of resection of lesion, neck dissection and reconstruction, and it has an impact on the position of hyoid bone. Therefore, morphological change of airway can occur since the geometric parameter of airway is correlated with the hyoid bone. Airflow is affected by geometry of the airway. In this study, flow characteristics were compared between pre- and post-surgery models by both particle image velocimetry (PIV) and numerical simulation. 3D model of upper airway was reconstructed based on CT data. Velocity is accelerated by the reduced channel area, and vortex and recirculation region are observed in pre- and post-surgery models. For the post-surgery model, high pressure distribution is developed by significantly decreased hydraulic diameter, and the longitudinal flow stream is also interrupted.

• Korean Journal of Head & Neck Oncology
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• v.23 no.1
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• pp.54-57
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• 2007

Fine needle aspiration biopsy(FNAB) has been used for many decades in the diagnosis of benign and malignant tumors of thyroid gland. Complications of thyroid fine-needle aspiration biopsy(FNAB) are extremely rare. Hematoma formation is the most commonly encountered complication. However, massive intrathyroid unilateral hemorrhage and hematoma formation inducing upper airway distress rarely occurs. Here, we report two cases diagnosed as having hematoma that caused upper airway distress after FNAB for thyroid nodule.