• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.547-561
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• 1998

Obstructive sleep apnea (OSA) is a disorder characterized by repetitive episode of upper airway collapse during sleep. Recent studies showed that not only the anatomic factors but the physiologic factors of the upper airway also have effcts on the occurrence of apnea and that the genioglossus muscle also plays an important role in the maintenance of the upper airway. A variety of therapies were performed to treat OSA, and among them the use of mandibular repositioning appliances showed reasonable results. But there is still a lack of research on the structural and physiological mechanism upon the use of mandibular repositioning appliances. The author selected 26(male 17, female 9) OSA patients that came to the Yonsei University Dental Hospital, Department of Orthodontics, and 20 normal adults (male 10, female 10) and took cephalometric radiographs of them in a supine position before and after the placement of the mandibular repositioning appliance to see the structural changes of the upper airway and compare the therapeutic effects between the two groups. We also studied the waking genioglossus muscle activity in OSA patients and investigated the difference in the electromyogram of the genioglosssus muscle upon the change in body posture and the use of mandibular repositioning appliance. Following results were obtained. 1. Among the cephalometric measurements of the upper airway structure, the length of the soft palate, maximum thickness of the soft Palate and SPAS, MAS, VAL, H-H1, MP-H showed statistically significant differences between the normal and OSA groups, but the IAS and EAS showed no statistically significant differences between the two groups. 2. In both the normal and OSA groups, as the epiglottis moved forward on wearing the mandibular repositioning appliance, the epiglottis level of the upper airway increased and the maximum thickness of the soft palate changed and the hyoid bone also moved forward, but the IAS in both groups showed various results and the effect of the mandibular repositioning appliance on the structure of the upper airway was different in the two groups. 3. Upon changing the position, the electromyogram of the genioglossus muscle showed a increasing tendency but there was no statistically significant differences, and when the mandibular repositioning appliance were worn there was a statistically significant increase in the electromyogram of the genioglossus muscle in both the upright and supine positions. The mandibular repositioning appliances not only have an effect on the anatomical structure of the upper airway but also on the physiology of the upper airway. There are different responses to the use of mandibular repositioning appliance between the normal and OSA groups therefore it could be considered to have the different physiology of the upper airway between the two groups.

• 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.

• 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.47 no.6
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• pp.353-364
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• 2017

Objective: The objective of this study was to investigate the effects of miniscrew-assisted rapid palatal expansion (MARPE) on changes in airflow in the upper airway (UA) of an adult patient with obstructive sleep apnea syndrome (OSAS) using computational fluid-structure interaction analysis. Methods: Three-dimensional UA models fabricated from cone beam computed tomography images obtained before (T0) and after (T1) MARPE in an adult patient with OSAS were used for computational fluid dynamics with fluid-structure interaction analysis. Seven and nine cross-sectional planes (interplane distance of 10 mm) in the nasal cavity (NC) and pharynx, respectively, were set along UA. Changes in the cross-sectional area and changes in airflow velocity and pressure, node displacement, and total resistance at maximum inspiration (MI), rest, and maximum expiration (ME) were investigated at each plane after MARPE. Results: The cross-sectional areas at most planes in NC and the upper half of the pharynx were significantly increased at T1. Moreover, airflow velocity decreased in the anterior NC at MI and ME and in the nasopharynx and oropharynx at MI. The decrease in velocity was greater in NC than in the pharynx. The airflow pressure in the anterior NC and entire pharynx exhibited a decrease at T1. The amount of node displacement in NC and the pharynx was insignificant at both T0 and T1. Absolute values for the total resistance at MI, rest, and ME were lower at T1 than at T0. Conclusions: MARPE improves airflow and decreases resistance in UA; therefore, it may be an effective treatment modality for adult patients with moderate OSAS.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.3
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• pp.463-469
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• 1996

Sonoring is caused by the repeated obstructions of versatile upper air way structure during sleep and is known as a kind of disease entity varing from simple snoring to obstructive sleep apnea syndrome(OSAS) which can cause serious cardiopulmonary complications due to its hypoxic pathophysiology. It has been reported that over 30% of middle-aged person have the problems of snoring and its accompanied symptomes and signs. Cephalometric measurements, frequently used to measure sella-nasion-subspinale(SNA) and sella-nasion-supramentale(SNB) angles, can provide the informations about the posterior airway space(PAS), the mandibular plane(MP) and the position of hyoid bone. These informations are useful in determining the therapeutic modalities of the snoring and OSAS patients. However, with conventional routine upright position, it does not represent the actual images of obstructive mechanism during sleep but only show the images of awaken normal upper airway anatomy. Therefore we have taken dual images of a routine upright lateral and a supine cephalometric view to compare both.

• Sleep Medicine and Psychophysiology
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• v.27 no.2
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• pp.33-40
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• 2020

An infant's sleep varies considerably from that of adults in terms of structure, amount, and breathing pattern. After birth, sleep becomes evenly distributed throughout the day and night. Nighttime sleep gradually increases with the maturation of circadian rhythm, and sleep is gradually consolidated. Electroencephalography characteristics change with age, from early and dominant active (REM) sleep in newborns to increasing NREM sleep. Similar to other elements of growth, the upper respiratory tract and ribcage gradually increase in size with age, and respiratory control also improves. With these changes, sleep patterns also change. At this time that various sleep disorders may appear. Improved understanding of age-dependent changes in infant sleep can help determine the etiology and facilitate diagnosis of infant sleep diseases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.2
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• pp.150-156
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• 2004

The etiology of the obstructive sleep apnea includes the various factors such as anatomical abnormality in upper airway, craniofacial structure, obesity and personal habit. To establish reasonable treatment plan, multi-department approach is should be emphasized because the treatment modality is depend on the result of analysis for degree & site of obstruction and various behavioral factors. In Sleep Clinic in Keimyung University Medical Center, the standard of care for sleep apnea patient was established according to the Standard of practice committee of Americal Sleep Disorders Association. After one year experience of comprehensive approach for sleep apnea we could achieve following recommendation for the treatment. 1) The multi-department examination and diagnosis could prevent unnessesary treatment because the treatment plan could be established under comprehensive discussion. 2) Determination of the site of obstruction is important for treatment planning. However, no single determinant could be found. We expect multi-department approach can reduce the mistake in detection of obstruction. 3) Further evaluation of treatmet outcome should be succeeded to establish Korean standard of care for sleep apnea treatment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.303-308
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• 2010

Excessive oral and maxillofacial bleeding causes upper airway obstruction, bronchotracheal and gastric aspiration and hypovolemic shock. Therefore, the rapid and correct bleeding control is very important for saving lives in the emergency room. Despite the conventional bleeding control methods of wiring (jaw fracture, wound suture and direct pressure), continuous bleeding can occur due to the presence of various bleeding disorders. There are five main causes for excessive bleeding disorders in the clinical phase; (1) vascular wall alteration (infection, scurvy etc.), (2) disorders of platelet function (3) thrombocytopenic purpura (4) inherited disorders of coagulation, and (5) acquired disorders of coagulation (liver disease, anticoagulant drug etc.). In particular, infections can alter the structure and function of the vascular wall to a point at which the patient may have a clinical bleeding problem due to vessel engorgement and erosion. Wound infection is a frequent cause of postoperative active bleeding. To prevent postoperative bleeding, early infection control using a wound suture with proper drainage establishment is very important, particularly in the active bleeding sites in a contaminated emergency room. This is a case report of a rational bleeding control method by rapid wiring, wound suture with drainage of a rubber strip & iodoform gauze and wet gauze packing, in a 26-year-old male cerebral palsy patient with active oral and maxillofacial bleeding injuries caused by a traffic accident.