• Journal of Oral Medicine and Pain
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• v.22 no.2
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• pp.383-394
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• 1997

The purpose of this study was to examine the anatomic changes in the upper airway with a dental orthosis. the effectiveness and side effects of orthosis in the treatment of snoring and obstructive sleep apnea. To meet this puppose a dental orthosis, designed to increase the size of the upper airway by advancing the mandible, was used in 42 patients (30 M, 12 F), aged 29 - 69 years, to treat snoring and varying decrees of obstructive sleep apnea. Cephalometric study of anatomic featured was made with and without a dental orthosis, and the evaluation of the effectiveness and side effects of orthosis was done by questionnaires. The obtained results were as follows : 1. All subjects were habitual snorers and 32 patients comp1ained the loudness of snoring as severe as be heard outside of the patient's room. 2. According to the degree of respiratory distirbance index(RDI) and aprea index(Al) from the polysomnograph in 34 patient, mild obstructive sleep apnea patients were 5, moderate 6 and severe 16. 3. Various anatomic changes in the upper airway with denta1 orthosis were as follows : (1) More superioly positioned hyoid bone ( p<0.001) (2) Enlarged oropharyngeal (superior p<0.01, middle p<0.01. inferior p<0.01) and hypopharyngeal (P<0.05) airway space. 4. According to the results of the changes of clinical syptoms after the usage of the dental orthosis acquired from questionnaires, there was significant improvement in the frequently, the loudness and the severity of snoring, cessation of breathing and awakening from the difficulty of breathing during sleep. 5. The effectiveness and side effects of dental orthosis by questionnaires were as follows ; (1) Dental orthosis satisfied almost all the patients (68±20%). (2) Snoring was improved in all the patients (73±19%). (3) Obstructive sleep aphea was improved in all the patients (61 ± 37%) (4) Sleepiness in the daytime was significantly improved (61 ±37%). (5) The sleep quality was significantly improved (61±37%). (6) The discomfort of the dental orthosis was minor (33±18%) and no serious complications were observed. 6. The dental orthosis is an effective treatment for the symptom of snoring, and it can also effectively treat varying degrees of obstructive sleep apnea.

• Clinical and Experimental Pediatrics
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• v.53 no.10
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• pp.863-871
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• 2010

The prevalence of pediatric obstructive sleep apnea syndrome (OSAS) is approximately 3% in children. Adenotonsillar hypertrophy is the most common cause of OSAS in children, and obesity, hypotonic neuromuscular diseases, and craniofacial anomalies are other major risk factors. Snoring is the most common presenting complaint in children with OSAS, but the clinical presentation varies according to age. Agitated sleep with frequent postural changes, excessive sweating, or abnormal sleep positions such as hyperextension of neck or abnormal prone position may suggest a sleep-disordered breathing. Night terror, sleepwalking, and enuresis are frequently associated, during slow-wave sleep, with sleep-disordered breathing. Excessive daytime sleepiness becomes apparent in older children, whereas hyperactivity or inattention is usually predominant in younger children. Morning headache and poor appetite may also be present. As the cortical arousal threshold is higher in children, arousals are not easily developed and their sleep architectures are usually more conserved than those of adults. Untreated OSAS in children may result in various problems such as cognitive deficits, attention deficit/hyperactivity disorder, poor academic achievement, and emotional instability. Mild pulmonary hypertension is not uncommon. Rarely, cardiovascular complications such as cor pulmonale, heart failure, and systemic hypertension may develop in untreated cases. Failure to thrive and delayed development are serious problems in younger children with OSAS. Diagnosis of pediatric OSAS should be based on snoring, relevant history of sleep disruption, findings of any narrow or collapsible portions of upper airway, and confirmed by polysomnography. Early diagnosis of pediatric OSAS is critical to prevent complications with appropriate interventions.

• Sleep Medicine and Psychophysiology
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• v.27 no.1
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• pp.1-7
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• 2020

Mobile digital devices are very familiar and useful devices in the daily life of modern people, and are used for various tasks such as communication, reading, writing, and playing media. As the use of mobile digital devices has become more prevalent, user time has also been increasing. In particular, the number of people who use digital devices before sleep is growing. The light pollution associated with these devices is classified into four categories: urban sky glow, glare, light trespass, and clutter. The pattern in which modern people use digital devices corresponds to light pollution caused by light trespass and clutter from light exposure to artificial light at night. The light pollution caused by digital devices can cause melatonin secretion suppression, delayed sleep onset, reduction of sleepiness before bedtime, and periodic rhythm and cognitive function disturbances. In addition, a study of children and adolescents showed there may be disturbances in the sleep-wake cycle and circadian rhythm, deterioration of sleep quality, and daytime fatigue due to light pollution caused by artificial light at night from mobile digital devices. A multi-faceted research effort is also necessary to investigate the healthy use of mobile digital devices based on research evidence and insights with an accurate evaluation of the influence of mobile digital devices as a form of light pollution.

• Mood & Emotion
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• v.12 no.2
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• pp.128-136
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• 2014

Objectives : This study was undertaken to investigate the prevalence of depressive symptoms and their related factors among a group of medical students. Method : A total of 874 (529 male and 345 female) medical students were randomly selected to participate in a survey. Depressive symptoms, satisfaction with life, health behavior including alcohol use, stress, sleep disturbance and happiness were collected using self-reported questionnaires. Results : The prevalence of depressive symptoms was 10.8%. In stepwise multiple regression analysis, lower satisfaction of life, daytime dysfunction due to sleepiness, history of suicidal attempt, stress, sleep disturbance were found to be significant relating factors of depressive symptoms. In moderated regression analysis, the result showed that the impact of life stress were moderated by satisfaction of life on depressive symptoms, but the moderating effect of happiness was not significant. Conclusion : This study showed considerably high prevalence of depressive symptoms and BDI score in medical students. The findings suggest that early detection of depressive symptoms and intensive mental health promotion program is needed in order to improve medical student's mental health status.

• Sleep Medicine and Psychophysiology
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• v.8 no.2
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• pp.107-112
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• 2001

Introduction: Narcolepsy, a sleep disorder characterized by excessive daytime sleepiness and cataplexy, is known to be closely associated with the human leukocyte antigen (HLA) DQB1*0602. Several studies have suggested that HLA-DQB1*0602 is strongly linked with narcolepsy-cataplexy. However, no studies have yet been made on whether HLA DQB1*0602 is associated with Korean patients with narcolepsy. This study was designed to investigate the frequency of HLA-DQB1*0602 of Korean patients with narcolepsy. Methods: Twenty patients were selected (mean age: $28.2{\pm}3.0$, 11 men and 9 women). The patients were confirmed to have narcolepsy by the overnight polysomnography and multiple sleep latency test (MSLT) in addition to their clinical history and symptoms at St. Vincent's Hospital and Korea University Hospital Sleep Disorders Clinic. Any subjects co-morbid with other hypersomnic sleep disorders such as sleep apnea or periodic limb movements during sleep were excluded. Clinical data was collected through a semi-structured interview for narcoleptic patients. All patients and 21 control did HLA typing for the presence of DQB1*0602. Results Obtained were as Follows: 1) Mean sleep latency was 2.4 (${\pm}2.0$ minutes) and mean frequency of sleep-onset REM period was 3.0 (${\pm}1.6$) by MSLT. 2) Characteristic symptoms of narcolepsy investigated were as follows: excessive daytime sleepiness (100%), cataplexy (100%), sleep paralysis (60%), hypnagogic hallucination (70%) and disrupted nocturnal sleep (75%). 3) Strong emotional expression such as laughing (80%) and joking (70%) triggered cataplexy which affects the knee and leg region (80%) and jaw region (30%). 4) HLA-DR2 was found in 90% of patients and 35% in controls. The frequency of HLA-DQB1*0602 in patients and controls was 90%, and 24%, respectively. Conclusions: These results, which exhibit high HLA-DQB1*0602 expression in Korean patients with narcolepsy, suggest that HLADQB1*0602 could be a strong genetic marker in narcolepsy.

• Sleep Medicine and Psychophysiology
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• v.20 no.2
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• pp.69-74
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• 2013

Introduction: Although it is well known that medical students are not getting an adequate amount of sleep, there have been only a few studies on the sleep patterns of medical students and the related factors. Therefore, the present study aimed to investigate the medical students' sleep patterns and the related factors. Methods: A questionnaire package was administered to the $1^{st}$ to $4^{th}$ year medical students at one medical school. It consisted of questions asking about their lifestyles as well as Pittsburgh sleep quality index (PSQI), Epworth sleepiness scale (ESS), global assessment of recent stress scale (GASS), the center for epidemiologic studies-depression scale (CES-D), and Moudsley obsessive-compulsive inventory (MOCI). A total of 352 students (206 males and 146 females) responded to the survey and the result was analyzed using the independent t-test, the chi-square test, the paired t-test, Pearson's correlation and ANOVA. p-values of less than 0.05 were considered statistically significant in analyses. Results: The weekend bedtime was significantly delayed (0 : 49 on weekday ; 1 : 34 on weekend ; t=-5.23, p<0.001), the weekend rise time was delayed (6 : 58 on weekday ; 9 : 30 on weekend ; t=-24.48, p<0.001) and the total sleep time was increased on weekends (5 : 36 on weekday ; 7 : 39 on weekend ; t=15.94, p<0.001). The PSQI score of all subjects was 6.43{\pm}2.64. PSQI was positively correlated with ESS (r=0.383, p<0.001), GASS (r=0.326, p<0.001), CES-D (r=0.393, p< 0.001), and MOCI (r=0.247, p<0.001), but not with GPA (r=0.072, p=0.228. The more senior students had lower PSQI, GASS, CES-D, and MOCI score (p<0.05). Conclusion: Medical students were experiencing a lack of sleep during weekdays as they have a later bedtime and earlier rise time, and consequently had more hours of sleep on weekends. Overall, the medical students were experiencing poor sleep quality and sleep deprivation. Poor sleep quality is associated with psychological problems (daytime sleepiness, stress, depression, and obsessive tendency).

• Sleep Medicine and Psychophysiology
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• v.13 no.2
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• pp.67-74
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• 2006

Introduction: Excessive daytime sleepiness and cataplexy are key features of narcolepsy. Modafinil is psychostimulant used in the treatment of narcolepsy. In this study, we evaluated effects of modafinil on nocturnal sleep structure and sleep latency in multiple sleep latency test and clinical features. Methods: Twelve narcoleptic patients (7 male, age: $22.9{\pm}2.6\;yrs$) were participated in the study. All of them had done nocturnal polysomnography (nPSG), multiple sleep latency test (MSLT), clinical symptoms scales and have repeated same procedure after taking 200 mg of modafinil. We have done linear mixed model analysis to describe effects of group, medication and nap time on these measures. Results: Modafinil did not affect clinical scales except PSQI which had been reduced after medication. In this study, Modafinil reduced total sleep time, sleep efficiency and increased wake after sleep onset and percent of arousal during sleep in nocturnal polysomnography and prolonged mean sleep latency in multiple sleep latency tests in both group. Discussion: Modafinil has stimulant effect of central nervous system but its effect on night sleep is less than other psychostimulants such as methylphenidate. We ascertained that modafinil affected total sleep time, sleep efficiency and percent of wake during sleep but did not effect on sleep structure. Modafinil was effective in the management of day time sleepiness. Modafinil can enhance alertness of control group without day time sleepiness.

• Sleep Medicine and Psychophysiology
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• v.19 no.2
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• pp.77-83
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• 2012

Objectives: Recent studies have reported a correlation between obstructive sleep apnea syndrome (OSA) and depression. In attempt to verify the suggestion that eveningness is related to depression, we examined the effect of morningness-eveningness on their depressive mood in patinets with OSA. Methods: The examination was based on the medical records and polysomnography reports of 211 OSA patients. Information was gathered from the patients who filled out the H$\ddot{o}$rne and Ostberg questionnaire (HOQ), profile of mood states-Korean version (K-POMS), and Epworth sleepiness scale (ESS). We compared mean values of K-POMS total, subscales of K-POMS, ESS, and OSA severity variables among the 3 morningness-eveningness groups (morningness, eveningness, and neither groups). Partial correlation analysis was performed between variables and ANCOVA was performed among the 3 groups after adjustment with age and weight. Results: There were significant negative correlations between HOQ and the followings : K-POMS total, POMS-T (tension-anxiety), POMS-D (depression-dejection), POMS-A (anger-hostility), POMS-F (fatigue-inertia), POMS-C (confusion-bewilderment), spontaneous arousal index, average O2 saturation. There were significant positive correlations between HOQ and the followings : POMS-V (vigor-activity), apnea-hypopnea index, respiratory arousal index, snore time. There were significant negative correlations between POMS-D and the followings : HOQ, POMS-V, stage 1 sleep (%), AHI, TAI (total arousal index), oxygen desaturation index, respiratory arousal index, neck circumference, average O2 desaturation, snore time (%). There were significant positive correlations between POMS-D and K-POMS total, POMS-T, POMS-A, POMS-F, POMS-C, sleep latency, stage 2 sleep (%), heart rate, spontaneous arousal index. There were significant differences in K-POMS total, POMS-T, POMS-D, POMS-F, POMS-C, spontaneous arousal index among the three HOQ groups in ANCOVA. Conclusion: The depressive correlates of OSA patients might be affected, not by excessive daytime sleepiness or OSA severity indexes, but by eveningness circadian characteristics. It would be important to take into account the morningness-eveningness tendency when we manage the depressive mood of OSA patients.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.216-224
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• 2015

This study aims to identify the prevalence of sleep related disease in those who experienced car accidents caused by drowsy driving. To this end, a survey of usual sleep habits, polysomnography, and multiple sleep latency tests were conducted in 34 persons who experienced an accident after normal sleep (Group 1), 22 persons who experienced an accident after abnormal sleep (Group 2), and 17 persons who was proven to be normal as a result of polysomnography and had no accident (Group 3). In all, 192 persons responded to the preliminary survey and the results were compared and analyzed. Crossover analysis was conducted to test the homogeneity of statistical characteristics, and the physical characteristics by age were analyzed. In the survey of sleeping habits, there was a significance between groups in how often they woke up while asleep (p<0.01), how difficult it was to go back to sleep again after waking up from sleep (p<0.05), how early they woke up in the morning (p<0.05), how difficult it was to get up in the morning (p<0.05), how sleepy they felt in the daytime (p<0.01), and how tired they felt in the daytime (p<0.01). Furthermore, among 56 subjects who had an accident during drowsy driving, 94.6% (53 persons) were found to have sleep related diseases. This suggests that car accidents during drowsy driving is not simply caused by temporary lack of sleep but by sleep related diseases even when sleep is adequate, leading to car accidents. Therefore, this study is significant identifying the association between car accidents during drowsy driving and sleep related disorders. Furthermore, the data would be considered basic to prepare social measures against drowsy driving related to such sleep related disorders.

• Sleep Medicine and Psychophysiology
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• v.22 no.1
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• pp.30-34
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• 2015

Obesity hypoventilation syndrome (OHS) is characterized by severe obesity, excessive daytime sleepiness, hypoxemia and hypercapnea. Because OHS mimics pulmonary hypertension or cor pulmonale, clinicians should recognize and treat this syndrome appropriately. A 58-year-old female visited the emergency room because of dyspnea. She was obese and had kyphoscoliosis. The patient also experienced snoring, recurrent choking during sleep and daytime hypersomnolence which worsened after gaining weight in the recent year. The arterial blood gas analysis showed she experienced hypoxemia and hypercapnea not only during nighttime but also daytime. We suspected OHS and the patient underwent polysomnography to confirm whether obstructive sleep apnea was present. During the polysomnography test, sleep obstructive apnea was observed and apnea-hypopnea index was 9.2/hr. The patient was treated with bilevel positive airway pressure therapy (BiPAP). After BiPAP for 4 days, hypoxemia and hypercapnia were resolved and she is currently well without BiPAP. We report a case successfully treated with clinical improvement by presuming OHS early in a patient who had typical OHS symptoms, even while having other conditions which could cause hypoventilation.