• Sleep Medicine and Psychophysiology
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• v.12 no.2
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• pp.93-97
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• 2005

Nasal obstruction may cause or aggravate sleep disordered breathing but exact pathogenesis is not clear. The possible mechanism could be combination of alteration in upper airway aerodynaimcs, loss of nasal reflex or sensation, effect of mouth opening, and a genetic predisposition. Anatomical narrowing of nasal airway cause more rapid airflow and induce more negative inspiratory air pressure. So, it increases collapsibility of pharyngeal airway. Loss of nasal sensation to airflow block nasal reflex. Mouth opening decreases the activity of pharyngeal airway dilator muscles and narrowing the pharyngeal airway may occur. The treatment of nasal obstruction should be done according to the cause. The causes of nasal obstruction are various from problems of external nasal opening to nasopharynx. Relief of nasal obstruction may not cure sleep disordered breathing always. In some mild obstructive sleep apnea patients, treatment of nasal obstruction only may cure sleep disordered breathing. In some severe sleep apnea patients, treatment of nasal obstruction may increase compliance of continous nasal positive airway pressure.

• Korean journal of aerospace and environmental medicine
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• v.28 no.2
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• pp.19-22
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• 2018

Obstructive sleep apnea syndrome (OSAS) can lead to severe complications if left untreated, and therefore should be adequately diagnosed and treated, especially in airline workers. The aviation medical examiner (AME) should induce the patient to cooperate for the diagnosis and treatment of OSAS, by notifying the subject that it does not cause disqualification of the air service and that it is a disease that can be sufficiently controlled and treated by various treatment options. AME should also warn about medical complications and the possibility of serious air accident risks when untreated, and encourage the subject to receive appropriate diagnosis and steady treatment such as continuous positive airway pressure and/or surgical treatment.

• Journal of Oral Medicine and Pain
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• v.48 no.3
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• pp.96-105
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• 2023

Purpose: Mandibular advancement devices (MAD) are known to be insufficiently effective in all patients with obstructive sleep apnea (OSA). This study aimed to compare the treatment outcomes of MAD therapy according to OSA severity and to investigate the risk factors for the lack of response to MAD therapy. Methods: A total of 29 patients diagnosed with OSA received an adjustable two-piece MAD treatment. Sleep parameters measured with the home sleep apnea test device, including apnea-hypopnea index (AHI) and oxygen saturation (SpO₂), and daytime sleepiness using the Epworth Sleepiness Scale (ESS) were retrospectively assessed both before and after the MAD treatment. Results: The patients were classified into three groups according to AHI severity: mild (n=16, AHI<15), moderate (n=6, 15≤AHI<30), and severe OSA (n=7, AHI≥30). MAD therapy significantly improved the sleep parameters (p<0.001 for AHI and p=0.004 for minimum SpO₂) and daytime sleepiness (p<0.001 for ESS). Furthermore, successful outcomes (reduction in AHI>50% and AHI<10 events/h) were achieved in 83.3% and 71.4% of moderate and severe OSA cases, respectively. Of 13 patients with moderate and severe OSA, 10 were classified as responders and 3 as non-responders. The non-responders had significantly lower baseline value of SpO₂ (p=0.049 for average SpO₂ and p=0.007 for minimum SpO₂) and higher baseline AHI (p=0.049) than the responders. Conclusions: The results of the present study suggest that MAD is effective in the majority of patients with OSA of varying severities. The success of MAD therapy does not seem to depend solely on AHI severity. In addition to AHI, minimum SpO₂ may be a prognostic measure of the efficacy of MAD treatment in clinical dental practice.

• Korean journal of aerospace and environmental medicine
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• v.31 no.2
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• pp.38-44
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• 2021

Purpose: This study aimed to identify the prevalence of fatigue and its associated factors leading to the fatigue among Korean commercial airline pilots. Methods: An anonymous, web-based questionnaire collecting data on sleep related characteristics was completed by airline pilots. The final 1,029 samples of completed questionnaires were analyzed. The association of the risk factors with fatigue was determined using logistic regression analysis. Results: The prevalence of fatigue was 60% (Fatigue Severity Scale index≥3.2), disturbed sleep 28% (Pittsburgh Sleep Quality Index≥9), daytime sleepiness 17% (Epworth Sleepiness Scale≥10), and sleep apnea (Berlin Questionnaire≥2) 11%. The fully adjusted logistic regression showed that quality of life (odds ratio [OR]=0.16, confidence interval [CI]=0.11-0.24), daytime sleepiness (OR=1.26, CI=1.18-1.34), sleep quality (OR=1.44, CI=1.29-1.61), mental workload (OR=1.10, CI=1.05-1.14), vigorous physical activity (OR=0.82, CI=0.72-0.92), late starts (OR=1.25, CI=1.06-1.46) and average weekly flying hours (OR=1.02, CI=1.00-1.03) were associated with higher levels of fatigue. Conclusion: Lower quality of life, disturbed sleep, more subjective sleepiness, shorter sleep duration, higher mental workload, less vigorous physical activity, frequent late starts, and longer flying hour were shown to be risk factors for fatigue in airline pilots. These findings should be taken into account in the development of sleep and fatigue countermeasures for airline pilots.

• Healthcare Informatics Research
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• v.24 no.4
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• pp.346-358
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• 2018

Objectives: The association between obstructive sleep apnea (OSA) and mortality or serious cardiovascular events over a long period of time is not clearly understood. The aim of this observational study was to estimate the clinical effectiveness of continuous positive airway pressure (CPAP) treatment on an outcome variable combining mortality, acute myocardial infarction (AMI), and cerebrovascular insult (CVI) during a follow-up period of 15.5 years ($186{\pm}58$ months). Methods: The data set consisted of 978 patients with an apnea-hypopnea index (AHI) ${\geq}5.0$. One-third had used CPAP treatment. For the first time, a data-driven causal Bayesian network (DDBN) and a hypothesis-driven causal Bayesian network (HDBN) were used to investigate the effectiveness of CPAP. Results: In the DDBN, coronary heart disease (CHD), congestive heart failure (CHF), and diuretic use were directly associated with the outcome variable. Sleep apnea parameters and CPAP treatment had no direct association with the outcome variable. In the HDBN, CPAP treatment showed an average improvement of 5.3 percentage points in the outcome. The greatest improvement was seen in patients aged ${\leq}55$ years. The effect of CPAP treatment was weaker in older patients (>55 years) and in patients with CHD. In CHF patients, CPAP treatment was associated with an increased risk of mortality, AMI, or CVI. Conclusions: The effectiveness of CPAP is modest in younger patients. Long-term effectiveness is limited in older patients and in patients with heart disease (CHD or CHF).

• Journal of Oral Medicine and Pain
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• v.39 no.2
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• pp.35-45
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• 2014

Many therapeutic modalities including continuous positive airway pressure, surgery, and oral appliances are used to treat patients with sleep-disordered breathing. However, there are no definitive treatment modalities for individual patients due to various causes of sleep-disordered breathing. Clinicians should have select best options for individual patients and it is quite challenging process. Oral appliances attracted clinical attention for its convenience and safety. Several designs of oral appliances are introduces such as soft palate lifter, tongue retaining device, and various appliances which aimed to mandibular advancement. Among these oral appliances, mandibular advancement devices (MADs) are considered the most excellent based on their effectiveness and patient tolerance. Although MADs are not guarantee dramatic outcome and less consistent than continuous positive airway pressure, they offer several advantages over continuous positive airway pressure and surgical methods, including non-invasiveness, silence, portability, and tolerability, simplicity. Therefore, general dental practitioner who had passed sleep dental curriculum or coursework can treat the patients with sleep problems. This article reviews the history, clinical indications, suggested mechanism of actions, various positive effects and several side effects, factors predicting a favorable outcome, determining amounts of mandibular advancement, compliance and long-term efficacy of MADs use.

• Sleep Medicine and Psychophysiology
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• v.8 no.2
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• pp.113-120
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• 2001

Objectives: Obstructive sleep apnea syndrome is common and may produce various symptoms and serious complications. A substantial number of research articles on obstructive sleep apnea syndrome have been published in Korea. However, we found such limitations as lack of sufficient sample size and lack of polysomnography-proven cases. Therefore, we aimed at studying clinical features and sleep structure in a sufficient number of Korean patients with obstructive sleep apnea syndrome diagnostically confirmed with polysomnography. Methods: We studied 801 subjects referred to the Division of Sleep Studies, Seoul National University Hospital, who were diagnosed as having obstructive sleep apnea syndrome with polysomnography. Subjects were excluded if they had central sleep apnea syndrome, periodic limb movement disorder, narcolepsy or REM sleep behavior disorder. Foreign patients were also excluded. First of all, we studied the clinical features of the subjects. Secondly, we compared sleep-related parameters of the study subjects with those of age/sex-matched normal values. Thirdly, correlations of respiratory disturbance index (RDI) with each of the sleep-related parameters were calculated. Results: Among the 801 subjects, 668 were male subjects (83.4%) and 133 female subjects (16.4%). Their mean age was 46.6 years (${\pm}13.5$). The mean body mass index (BMI) was 25.8 (${\pm}3.8$) and subjects with BMI was over 28.0 accounted for 22.8% of the total. Fifty subjects (6.2%) were found to take benzodiazepines. Mean RDI and mean nocturnal oxygen saturation of all subjects was 31.2 (${\pm}24.4$) and 94.5% (${\pm}3.6$), respectively. In comparison with normal values, the subjects showed longer sleep latency, lower sleep efficiency, decreased total slow wave sleep % (TSWS %), and decreased total REM sleep % (TREM %)(p<0.01 in all). RDI had a negative correlation with each TSWS % and TREM % (p<0.01, p<0.01). However, RDI did not have significant correlation with either sleep latency or sleep efficiency. Conclusion: In this study, 6.2% of patients diagnosed as having obstructive sleep apnea syndrome were found to take benzodiazepines, although they are generally considered to be of litte benefit or even dangerous because of the respiratory suppressing effect. The proportion of obese subjects was only 22.8% and Korean patients with obstructive sleep apnea syndrome seem to be less obese than those described in foreign journals. This study also suggests that the severity of obstructive sleep apnea syndrome may have a more significant effect on sleep architecture defined as TSWS % and TREM % than on sleep efficiency.

• Imaging Science in Dentistry
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• v.46 no.1
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• pp.9-16
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• 2016

Purpose: To evaluate the upper airway dimensions of obstructive sleep apnea (OSA) and control subjects using a cone-beam computed tomography (CBCT) unit commonly applied in clinical practice in order to assess airway dimensions in the same fashion as that routinely employed in a clinical setting. Materials and Methods: This was a retrospective analysis utilizing existing CBCT scans to evaluate the dimensions of the upper airway in OSA and control subjects. The CBCT data of sixteen OSA and sixteen control subjects were compared. The average area, average volume, total volume, and total length of the upper airway were computed. Width and anterior-posterior (AP) measurements were obtained on the smallest axial slice. Results: OSA subjects had a significantly smaller average airway area, average airway volume, total airway volume, and mean airway width. OSA subjects had a significantly larger airway length measurement. The mean A-P distance was not significantly different between groups. Conclusion: OSA subjects have a smaller upper airway compared to controls with the exception of airway length. The lack of a significant difference in the mean A-P distance may indicate that patient position during imaging (upright vs. supine) can affect this measurement. Comparison of this study with a future prospective study design will allow for validation of these results.

• Journal of Clinical Otolaryngology Head and Neck Surgery
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• v.29 no.2
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• pp.190-197
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• 2018

Background and Objectives : Positional OSAS is characterized by an apnea-hypopnea index (AHI) score >5, which, while sleeping in the supine position, is double that in non-supine position. This study was performed to compare the clinical characteristics of positional OSAS and non-positional OSAS patients, and the effects of the modified jaw thrust maneuver during drug-induced sleep endoscopy (DISE) between positional OSAS and non-positional OSAS patients. Materials and Methods : 68 positional OSAS patients and 19 non-positional OSAS patients were included. They all underwent full-night polysomnography and DISE. The modified jaw thrust maneuver was introduced during DISE. Airway structural changes induced by the modified jaw thrust maneuver were evaluated and documented. Results : There were no statistically significant differences in Friedman stage or tonsil grade, body mass index, Epworth sleepiness scale (ESS) score, blood pressure, AHI, or obstructive pattern between the positional and non-positional OSAS patients. However, mean arterial oxygen saturation (SaO2), lowest SaO2, and total arousal index values were more severe in the non-positional OSAS patients. After introduction of the modified jaw thrust maneuver, retrolingual level obstruction showed a tendency toward a higher rate of airway opening in positional OSAS patients than in non-positional OSAS patients. Conclusions : The effects of a mandibular advancement device (MAD) can be estimated by carrying out a modified jaw thrust maneuver during DISE. The tendency toward a higher rate of airway opening in positional OSAS patients than non-positional OSAS patients in retrolingual level obstruction after jaw thrust maneuver introduced during DISE may be clinically important for MAD.

• Journal of Oral Medicine and Pain
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• v.40 no.2
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• pp.63-71
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• 2015

Purpose: To investigate the relationship between headache and sleep by evaluating sleep quality, daytime sleepiness, and specific features related to sleep-disordered breathing (SDB). Methods: One hundred one subjects with headache and 118 healthy controls were enrolled. To collect various information on headache attacks, headache group completed self-reported questionnaire about the characteristics of headache attacks and the migraine disability assessment (MIDAS) questionnaire. The subjective quality of sleep was evaluated in all of the subjects using the Pittsburgh sleep quality index (PSQI) and Epworth sleepiness scale (ESS). In addition, the following specific features of sleep were evaluated in 28 subjects selected randomly from each group: apnea-hypopnea index (AHI), prevalence of SDB, nocturnal oxygen saturation (SaO2), and oxygen desaturation index (ODI) as measured using a portable monitoring device. Results: The global PSQI and the prevalence of poor sleeping (global PSQI >5), ESS scores and the prevalence of daytime sleepiness (ESS score >10) were significantly higher in the headache group (both p<0.0001, respectively). The mean scores on the numerical rating scale and the MIDAS were significantly higher in the poor-sleeper group than in the good-sleeper group (p=0.0347 and p=0.0016, respectively). The global PQSI and prevalence of daytime sleepiness were significantly higher in the chronic-headache group than in the acute-headache group (p=0.0003 and p=0.0312, respectively). Conclusions: There is a significant association between headache and sleep. Especially, severity and chronicity of headache were significantly associated with sleep quality and daytime sleepiness.