Oral Appliance Research Articles

P056 REducing Sleep Apnoea for the PrEvention of Dementia (REShAPED): The protocol of a multi-site feasibility randomised controlled trial

Abstract Background Obstructive sleep apnoea (OSA) is estimated to occur in up to 70% of older adults. There is accumulating evidence linking OSA with increased risk of cognitive decline and dementia. Here, we present the protocol for a pilot multi-site randomised controlled, parallel open-label trial which will evaluate the feasibility for a full-scale trial investigating the effects of treating OSA on cognitive decline in older adults at risk for dementia with OSA within memory clinic settings. Methods We will randomise 180 older adults to either the intervention group or to the control group for 2 years. Inclusion criteria include: 50-75 years; mild-severe OSA (defined average ODI≥10 with 3% oxygen desaturation determined by wrist oximetry over two nights); and subjective cognitive complaints or mild cognitive impairment. The treatment intervention arm intends to achieve an optimal treatment response based on reducing hypoxic burden with either CPAP, mandibular advancement splint, positional therapy, or oxygen therapy. Furthermore, participants will receive up to 8 sessions which involve motivational interviewing and collaborative goal setting to support OSA treatment adherence, and behavioural sleep management. The control arm will not receive OSA treatment as part of this trial, however there will be no OSA treatment restrictions, and any treatment pursued outside the trial will be documented. Primary outcomes are 1) acceptability of the trial participants; 2) alleviating hypoxic burden by reducing OSA severity; 3) tolerability of the outcome assessments. Secondary outcomes include safety and cognitive function. Outcomes will be collected at 0, 6 and 24-months.

O057 Effects of oral appliance therapy on upper airway collapsibility pre- versus post-treatment

Abstract Introduction A key predictive mechanism of improvement in obstructive sleep apnoea (OSA) severity with oral appliance therapy (OAT) is a less collapsible upper airway. In this study, we investigate the effects of acute versus longer-term use of OAT on upper airway collapsibility. Methods To investigate potential changes in upper airway collapsibility we studied 10 treatment naïve people (2 female) with OSA (AHI=40±31events/h, age=51±11years, BMI=29±4kg/m-2) at baseline and following 4-6 weeks oral appliance therapy acclimatization. The upper airway collapsibility index was measured during wakefulness with/without the oral appliance in place at two time points (pre/post treatment). All participants were instrumented with standard polysomnography equipment, two pressure catheters (one at the level of the choanae, and the other at the epiglottis), a pneumotachograph, sealed nasal mask and a short tubing connected to a breathing circuit to allow rapid delivery of negative pressure ~-11cmH₂O to the mask. Results The upper airway collapsibility index measured during early inspiration was reduced by 11% (33±19 vs. 22±16%, n=10, p=0.02) with OAT in place in treatment naïve participants. Similarly, following acclimatization, the upper airway collapsibility index also reduced by 7% with OAT in place (25±15 vs. 18±15%, n=9, p=0.03). Conclusions While further work is required to determine if long-term OAT independently improves upper airway collapsibility, these data show sustained improvements in upper airway collapsibility with OAT over time and highlight the potential for this approach to help predict OAT treatment outcomes.

P086 The insomnia severity index is related to the respiratory arousal threshold in people with Co-Morbid Insomnia and Sleep Apnoea (COMISA)

Abstract Introduction People with co-morbid insomnia and sleep apnoea (COMISA) have worse symptoms and require a tailored therapy approach for their sleep disorders. The relationship between the respiratory arousal threshold, a key OSA non-anatomical contributor and insomnia symptoms is unclear. This study investigated the relationship between insomnia symptoms using the insomnia severity index (ISI) and the respiratory arousal threshold in people with OSA. Methods 46 people with OSA (11 female, age=50±15years, BMI=29±6kgm-2, AHI=33±20events/h) participated in a physiology sleep study to predict response to oral appliance therapy and completed the ISI. Standard polysomnography, an epiglottic airway pressure sensor, bipolar intramuscular electrodes inserted into the genioglossus and a nasal mask with a pneumotachograph to quantify airflow were used. The respiratory arousal threshold was measured as the nadir epiglottic pressure during a respiratory event prior to a cortical arousal. Following this, participants trialled mandibular advancement therapy. Results There was no relationship between ISI (average=12±6) and the arousal threshold (-24±10cmH₂O) in participants with OSA (r=0.1, p=0.42, n=46). However, in the 59% of people with COMISA (ISI ≥11), there was a positive relationship between ISI and arousal threshold, with increasing insomnia severity associated with lower arousal threshold (r=0.5, p=0.017, n=27). People with a BMI<30kgm-2 (n=27), also had a positive linear relationship between ISI and improvement in oral appliance therapy (r=0.49, p<0.01, n=27). Conclusion Greater insomnia symptoms in people with COMISA is associated with a lower respiratory arousal threshold. In non-obese people with OSA, higher ISI values are related to poor response to oral appliance therapy.

P004 Addition of an oral expiratory positive pressure valve (EPAP) to an oral appliance therapy device can resolve obstructive sleep aponea (OSA)

Abstract Background Mandibular advancement splints (MAS) provide effective therapy for many people with OSA. However, in ~50% of cases, MAS alone does not fully resolve OSA. A single-night study showed that ~45% of people with incompletely treated OSA with MAS alone had resolution (apnoea-hypopnea index [AHI]<10 events/h) with the addition of an oral expiratory positive airway pressure (EPAP) valve. This study aimed to determine the safety, tolerability, and longer-term efficacy of oral EPAP valve plus MAS in incomplete responders to MAS alone. Methods Seven people with OSA (AHI=26±13events/h) not fully resolved with MAS alone (AHI>10events/h) were recruited. In-laboratory polysomnography with MAS plus oral EPAP was performed on night 1. Participants then used MAS+EPAP at home for 30-days and completed weekly questionnaires to assess safety, tolerability, and next-morning sleepiness (Karolinska sleepiness scale, KSS). Impact on daytime sleepiness (Epworth sleepiness scale, ESS) was assessed at night 1 and 30. A final at-home WatchPAT study was performed at night 30. Results OSA was successfully treated (AHI<10events/h) in 4/7 participants during the night 1 in-laboratory study (MAS alone vs. MAS+ EPAP 13±2 vs. 7±2events/h). Five had treatment success by night 30 (6±3events/h). Daytime sleepiness (ESS) did not change after 30 days of MAS+EPAP although next-morning sleepiness tended to reduce ( KSS 4.4±1.9 vs. 3.3±1.5, p=0.047 n=7). Oral EPAP was generally well-tolerated with no major side effects reported. Discussion Oral EPAP may be an effective treatment addition for some people with OSA who have an incomplete therapeutic response to MAS alone.

O026 Effect of oral appliance therapy on OSA endotypes

Abstract Introduction Long term CPAP therapy alters OSA endotypes (e.g., reduces loop gain and the arousal threshold). However, while oral appliance therapy (OAT) is known to improve upper airway collapsibility, its effects on non-anatomical OSA endotypes are unclear. Methods To investigate the effects of OAT on polysomnographic estimates of OSA endotypes we studied 102 people with OSA (AHI=34±20 events/h) pre vs. post-treatment (following 4-6 weeks OAT acclimatization). AHI and endotypic traits were compared between the diagnostic and OAT study visits. Results OAT reduced the AHI by ~50% (30 [25-39] vs. 15 [12-19], median, 95% confidence interval, p<0.01). Passive pharyngeal collapsibility (94 [92-95] vs. 96 [95-97]% eupnea), active pharyngeal collapsibility (98 [95-100] vs. 102 [101-103]% eupnea) and pharyngeal muscle compensation (3.6 [1.2-5.1] vs 4.9 [3.7-6.5]% eupnea) improved with OAT (all p<0.01). The respiratory arousal threshold (116 [114-122] vs. 109 [106-111]% eupnea, p<0.01) and ventilatory response to arousal (31 [28-35] vs. 23 [20-32]% eupnea, p=0.03) decreased. Loop gain did not systematically change overall (0.43 [0.39-0.47] vs. 0.40 [0.38-0.42], p=0.16). However, loop gain reduced in OAT responders (>50% reduction in AHI) (0.42 [0.39-0.45] vs. 0.38 [0.34-0.4] dimensionless, p<0.01). Conclusions Oral appliance therapy improves upper airway collapsibility and pharyngeal muscle compensation and reduces the ventilatory response to arousal and loop gain in responders. Like CPAP, OAT also decreases the arousal threshold. These findings provide new insight into the mechanisms of improvement in OSA with oral appliance therapy.

O031 Independent validation of a physiology-based model to predict oral appliance treatment outcomes

Abstract Background Oral appliance therapy (OAT) is a well-tolerated treatment for obstructive sleep apnoea (OSA). However, efficacy varies. On average, OAT reduces OSA severity by ~50% leaving a substantial proportion of OAT patients either undertreated or untreated. Thus, a major clinical priority is to develop clinically feasible prediction tools to accurately predict which patients will respond to OAT and vice versa. Accordingly, we developed a model to estimate OSA endotypes and have adapted it to predict OAT outcomes. Here we used our recently developed physiology-based OAT prediction model to predict OAT responses in an independent validation sample. Methods 91 people with OSA who were prescribed OAT by their treating physician had an in-laboratory diagnostic study followed by an OAT efficacy polysomnography after ≥4 weeks acclimatisation. 7 polysomnography variables from the diagnostic study plus age and body mass index were included in our machine learning based model designed to predict OAT response. Prediction performance characterises according to standard apnoea/hypopnoea index (AHI) definitions were assessed. Results Mean accuracy of the model to predict OAT responders vs. non-responders in this independent validation sample was high across different OSA treatment outcome definitions ranging from 70% (>50% reduction in AHI), 79% (AHI<10 events/h) to 95% (AHI<5 events/h). Corresponding specificity was also high at 87%, 97% and 99%, respectively. Discussion These new findings provide additional support for the use routinely collected sleep study and clinical data with machine learning based approaches underpinned by OSA endotype concepts to help predict OAT treatment outcomes for people with OSA.

Arch Measurement Changes upon Biomimetic Oral Appliance Therapy for Adults with Obstructive Sleep Apnea

Background: Obstructive Sleep Apnea (OSA) is the most common form of sleep disordered breathing. Patients who arrive at the dental office with a diagnosis of OSA are often treated with a mandibular advancement device (MAD). A biomimetic oral appliance therapy (BOAT) offers an alternative nonsurgical method, which can putatively resolve OSA by combining maxilla-mandibular correction and addressing craniofacial deficiencies. Aim: To determine whether maxilla-mandibular correction changes induced by BOAT produce a more favorable upper airway, which might result in a reduction in the severity of OSA. Methods: Patients who were diagnosed with mild to moderate obstructive sleep apnea (OSA, 9 males, 8 females; age, mean (SD): 45.76(10.31), BMI mean (SD): 33.5(13.43), underwent BOAT therapy. Subjects had 2 months of follow-up visits, including examinations for progress and adjustment of the appliances. The mean apnea-hypopnea index (AHI) with no appliance in the mouth prior to BOAT and after treatment was recorded. The mid-palatal screw mechanism of the appliance was advanced once per week. The subjects were asked to wear the appliance for 10-12 hours/day and night. Paired T-Test was used to analyze the results. Results: The BOAT treatment enhanced upper airway function as the total AHI was significantly lower after treatment (P=0.019). Parameters that were significantly improved by the end of the treatment period included total AHI/Per hour of sleep (p=0.019), NREM-AHI (p=0.019), desaturation index (p=0.041), average SpO2 (p=0.088), and average O2 while in non-REM (p=0.043). Measurements of jaw changes were all statistically significant except lower 6-6 and lower 7-7. Additionally, a strong negative correlation between AHI and jaw changes was shown for upper 6-6 (p=-0.52), upper 7-7 (p=-0.48), and lower 3-3 (p=-0.42). Conclusion: The BOAT provides a useful form of therapy for the resolve of OSA. This study suggests that BOATS may be able to reduce the AHI to within normal limits. Still, long-term follow-up is needed to determine whether these subjects need a maintenance program to retain their initial upper airway improvement.

Treatment of Obstructive Sleep Apnea Using Oral Appliances in Saudi Arabia: Are We following the Guidelines?

This study aimed to assess sleep medicine physicians' knowledge and attitudes toward the role of oral appliances (OAs) in managing obstructive sleep apnea (OSA) in Saudi Arabia. An online questionnaire was administered to the registered physicians practicing sleep medicine (otolaryngology, internal medicine, pulmonology, and family medicine) in Saudi Arabia. The questionnaire included 26 questions under five domains. All the collected data were analyzed using descriptive statistics and Chi-square tests. One hundred sleep physicians (43% Saudi, 75% male) from Saudi Arabia participated in this study. Almost 43% of participants reported inadequate knowledge of the treatment of OSA patients using OAs. Half of the participants were unaware of how OAs work in managing OSA. Most physicians (62%) never referred the patient for treatment of OSA using OAs, whereas 4% referred at least one patient every month. The majority (60%) believed that there are barriers to referring a case for OA treatment, mainly the lack of knowledge of the suitable cases (60%) and the lack of qualified dentists in this area (43%). Most sleep physicians reported poor knowledge of OA indications and mechanism of use, with most never referring a case for OA therapy.

Fabricating a custom monoblock mandibular advancement device by using an open-source nondental CAD software program and additive manufacturing: A dental technique

Custom mandibular advancement devices (MADs) can be fabricated by using either conventional processes or computer-aided design and computer-aided manufacturing (CAD-CAM). The CAD-CAM technique involves digitizing the dental arches of the patients, designing by using a dental CAD software program, and additive manufacturing with a suitable material. This article describes the steps of the design of a custom MAD by using an open-source nondental CAD software program and of the fabrication with additive manufacturing.

Differences in Long-term Efficacy of Oral Appliance Therapy for Obstructive Sleep Apnea According to Polysomnographic Phenotypes

Differences in Long-term Efficacy of Oral Appliance Therapy for Obstructive Sleep Apnea According to Polysomnographic Phenotypes

Mandibular Torus as a New Index of Success for Mandibular Advancement Devices.

In obstructive sleep apnoea (OSA), treatment with mandibular advancement devices (MADs) reduces patients' Apnoea-Hypopnoea index (AHI) scores and improves their sleepiness and quality of life. MADs are non-invasive alternatives for patients who cannot tolerate traditional continuous positive airway pressure (CPAP) therapy. The variability of responses to these devices makes it necessary to search for predictors of success. The aim of our study was to evaluate the presence of mandibular torus as a predictor of MAD efficacy in OSA and to identify other potential cephalometric factors that could influence the response to treatment. This was a retrospective cohort study. The study included 103 patients diagnosed of OSA who met the criteria for initiation of treatment with MAD. Structural variables were collected (cephalometric and the presence or absence of mandibular torus). Statistical analysis was performed to evaluate the existence of predictive factors for the efficacy of MADs. A total of 103 patients who were consecutively referred for treatment with MAD were included (89.3% men); the mean age of the participants was 46.3 years, and the mean AHI before MAD was 31.4 (SD 16.2) and post- MAD 11.3 (SD 9.2). Thirty-three percent of patients had mandibular torus. Torus was associated with a better response (odds ratio (OR) = 2.854 (p = 0.035)) after adjustment for sex, age, body mass index (BMI; kg/m2), the angle formed by the occlusal plane to the sella-nasion plane (OCC plane to SN), overinjection, and smoking. No cephalometric predictors of efficacy were found that were predictive of MAD treatment success. The presence of a mandibular torus practically triples the probability of MAD success. This is the simplest examination with the greatest benefits in terms of the efficacy of MAD treatment for OSA.

Minimization of Adverse Effects Associated with Dental Alloys.

Metal alloys are one of the most popular materials used in current dental practice. In the oral cavity, metal structures are exposed to various mechanical and chemical factors. Consequently, metal ions are released into the oral fluid, which may negatively affect the surrounding tissues and even internal organs. Adverse effects associated with metallic oral appliances may have various local and systemic manifestations, such as mouth burning, potentially malignant oral lesions, and local or systemic hypersensitivity. However, clear diagnostic criteria and treatment guidelines for adverse effects associated with dental alloys have not been developed yet. The present comprehensive literature review aims (1) to summarize the current information related to possible side effects of metallic oral appliances; (2) to analyze the risk factors aggravating the negative effects of dental alloys; and (3) to develop recommendations for diagnosis, management, and prevention of pathological conditions associated with metallic oral appliances.

Low Arousal Threshold Estimation Predicts Failure of Mandibular Advancement Devices in Obstructive Sleep Apnea Syndrome.

Introduction: The treatment of choice for obstructive sleep apnea syndrome (OSAS) is continuous positive airway pressure (CPAP). However, CPAP is usually poorly tolerated and mandibular advancement devices (MADs) are an alternative innovative therapeutic approach. Uncertainty still remains as to the most suitable candidates for MAD. Herein, it is hypothesized that the presence of low arousal threshold (low ArTH) could be predictive of MAD treatment failure. Methods: A total of 32 consecutive patients, with OSAS of any severity, who preferred an alternate therapy to CPAP, were treated with a tailored MAD aimed at obtaining 50% of their maximal mandibular advancement. Treatment response after 6 months of therapy was defined as AHI < 5 events per hour or a reduction of AHI ≥ 50% from baseline. Low ArTH was predicted based on the following polysomnography features, as previously shown by Edwards et al.: an AHI of 82.5% and a hypopnea fraction of total respiratory events of >58.3%. Results: There were 25 (78.1%) responders (p-value < 0.01) at 6 months. Thirteen patients (40.6%) in the non-severe group reached AHI lower than 5 events per hour. MAD treatment significantly reduced the median AHI in all patients from a median value of 22.5 to 6.5 (74.7% of reduction, p-value < 0.001). The mandibular advancement device reduced AHI, whatever the disease severity. A significant higher reduction of Delta AHI, after 6 months of treatment, was found for patients without low ArTH. Conclusions: Low ArTH at baseline was associated with a poorer response to MAD treatment and a lower AHI reduction at 6 months. A non-invasive assessment of Low ArTH can be performed through the Edwards’ score, which could help to identify an endotype with a lower predicted response to oral appliances in a clinical setting.

Oral Appliances for Severe Positional Obstructive Sleep Apnea Syndrome: A Case Report

Severe positional obstructive sleep apnea syndrome (POSAS) is a common clinical respiratory disorder with an incidence of 26.7% to 74.5%. Continuous positive airway pressure (CPAP) combined with positional therapy is the gold standard of treatment. However, a mandibular advancement device (MAD) is an effective alternative to CPAP when compliance with CPAP is low or if CPAP is rejected by the patient. A 63-year-old Caucasian male (BMI 26.1 kg/m2) complaining of repeated episodes of daytime sleepiness and heavy snoring was diagnosed with POSAS and treated with a MAD. After two years, polysomnographic (PSG) control analysis showed a significant reduction in the number of obstructive sleep apnea/hypopnea episodes per hour (AHI) by 58.9% in the lateral position and 75.5% in the supine position, complete remission of symptoms, a significant reduction in the severity of POSAS, and an overall improvement in quality of life. No adverse events or reduction in compliance were observed during the follow-up period. For severe POSAS, MADs may be an alternative method that is well tolerated by patients and has a good safety profile.

Comparison of the Effectiveness of Orthodontic Treatment with Adenotonsillectomy Procedures in Children with Obstructive Sleep Apnea (OSA)

Background: Obstructive Sleep Apnea Syndrome (OSA) is a syndrome of total or partial obstruction of the airways, leading to significant disturbances with varying clinical impact. In children, the main cause is thought to be overgrowth (hypertrophy) of the tonsils and adenoids, as well as structural abnormalities in Pierre Robin and Down Syndrome. The airway structures are significantly narrowed in children with head-face bone abnormalities or craniofacial anomalies, causing them to experience airway obstruction even in the absence of adenoid hypertrophy. The incidence of OSA in children needs to be observed as well as rising risk factors such as obesity. Pediatric obstructive sleep apnea (OSA) is typically treated with an adenotonsillectomy and the use of orthodontic procedures including rapid maxillary expansion and mandibular advancement devices. Each approach has different treatment advantages. Systematic reviews and meta-analysis of OSA treatments have been reported, however there have been relatively few comparisons of various treatments. In a systematic review of the evidence for the efficacy of AT and orthodontic treatment, Templier et al. concluded that combined AT orthodontic treatment (RME and/or MAD) was more effective than either therapy alone for treating OSA in pediatric patients. Objective: To systemically analyze the literature on the effectiveness of orthodontic treatment with adenotonsillectomy surgery in children with obstructive sleep apnea (OSA) and to identify differences in the two treatments’ effectiveness. Conclusion and implications: The effectiveness of adenotonsillectomy, orthodontic treatment, and orthodontic treatment combined with adenotonsillectomy was assessed in children with mild OSA and mandibular retrognathia. That study, which needed a large sample size (352 children) and had a high dropout rate, revealed that combine orthodontic adenotonsillectomy (RME and/or MAD treatment) was more effective when given simultaneously than when given individually for treating OSA in pediatric patients. To date, the effectiveness of these two treatments cannot currently be compared due to a lack of strong evidence. If the treatment outcomes were unsatisfactory at 7 months after the initial treatment, subjects could receive further treatment following assessment by a stomatologist and ear, nose, and throat (ENT) specialist. Limitations: Of the 10 publications included in this review, 8 were randomized controlled trials, the remaining 2 non-randomized research journals were vulnerable to many biases that impair the certainty of the evidence gained, especially by confounding factors and the lack of control groups.

Dental Sleep Medicine Standards for Screening, Treatment, and Management of Sleep-Related Breathing Disorders in Adults Using Oral Appliance Therapy: An Update

Dental Sleep Medicine Standards for Screening, Treatment, and Management of Sleep-Related Breathing Disorders in Adults Using Oral Appliance Therapy: An Update

Dental Sleep Medicine among dental practitioners: Preliminary findings from the National Dental Practice-Based Research Network.

Dental sleep medicine (DSM) focuses on oral appliance therapy (OAT) to manage sleep-disordered breathing (SDB), including obstructive sleep apnea (OSA). This brief poll aimed to assess the interest and practices of dental practitioners in DSM. To this day lack of data exists regarding how DSM practices function in the clinical setting. Therefore, identifying knowledge gaps in DSM among dental practitioners may improve patient outcomes. A preliminary brief questionnaire ("Quick Poll") on DSM was conducted through the National Dental Practice-Based Research Network (Network) members (n=311). The poll contained five questions about DSM. Results showed that 66% of practitioners have involvement in DSM patient care. A total of 44% of practitioners who answered the Quick Poll do not screen for snoring or SDBs. About 40% of respondents are either interested in continuing education courses on the topic or had already taken multiple courses on DSM. The top three topics of DSM research of interest to practitioners were various DSM practice models, response to OAT, and compliance with OAT. Network dental practitioner respondents face challenges regarding the treatment of SDBs. Despite these challenges, most practitioners are interested in engaging in DSM. Based on these preliminary findings, there are informational needs regarding the current state of clinical care, side effects of OAT, choice of OAT, titration protocols, and patient outcomes.

Influence of MAD Application on Episodes of Obstructive Apnea and Bruxism during Sleep-A Prospective Study.

The condition of sleep bruxism (SB) is defined by many authors as the body’s response to obstructive sleep apnea (OSA). In the conservative treatment of OSA, mandibular advancement devices (MADs) have found their application. The aim of the study iso assess the impact of MADs on the occurrence of episodes and the intensity of OSA and SB. The study sample consisted of eight patients with OSA and SB diagnosed with these conditions on the basis of clinical examinations and polysomnography (PSG). The prospective study was designed to assess the use of MADs for OSA and SB. MADs were prepared for the patients who subsequently underwent control examinations after one week of wear, and another PSG (PSG II) with an MAD was performed in conditions resembling the first qualification examination (PSG I). The same parameters were assessed in both PSG examinations. Following treatment with the MAD, a favorable lowering of the mean values of the examined parameters was observed. The statistically significant differences were demonstrated only for the apnea–hypopnea index (AHI), the oxygen desaturation index (ODI), and the number of apneas and hypopneas, obstructive apneas, apneas in OSA, and phasic episodes of bruxism. The application of MADs in patients with OSA has a beneficial effect on the same manifestations of OSA and SB, even though only the number of phasic episodes of bruxism was statistically significant.

Surgical Outcomes for Obstructive Sleep Apnea in Korea

Obstructive sleep apnea (OSA) is a common chronic sleep disorder that causes oxygen desaturations, sympathetic hyperactivation, and sleep fragmentation. The gold standard for OSA treatment in adults is positive airway pressure (PAP) therapy, which is effective when used during sleep. However, about half of patients with OSA refuse or are non-adherent to PAP, and some patients have anatomical problems that can be alleviated surgically. Surgery can be considered for patients who are very likely to have successful surgical results, but who are intolerant to PAP or oral appliances because of anatomical abnormalities. There are various surgical modifications of the upper airway for OSA, including nasal surgeries (e.g., septoplasty, turbinoplasty, and endoscopic sinus surgery), nasopharyngeal surgeries, oral and oropharyngeal surgeries (e.g., uvulopalatopharyngoplasty and variations, tonsillectomy, and palatal implants), hypopharyngeal surgeries (e.g., tongue ablation, tongue-base resection, and genioglossus advancement), and multi-level surgeries. Much clinical research has reported the outcomes of various surgical procedures for OSA internationally based on the traditional surgical success rate (defined as ≥ 50% reduction in the postoperative apnea-hypopnea index [AHI], postoperative AHI &lt; 20), and AHI reduction ratio (defined as between the preoperative and postoperative AHI). In addition, many studies investigating the results of various OSA surgeries have been reported in Korea. In this article, we review the characteristics of various upper airway surgical procedures for OSA, global surgical results for OSA, and current surgical outcomes for OSA in Korea.

Is the response rate of oral appliance therapy for subjects with and without position-dependent obstructive sleep apnoea different?

Objective To compare the effect of oral appliance (OA) treatment on non-position-dependent obstructive sleep apnoea (non-POSA) and position-dependent obstructive sleep apnoea (POSA).Methods The investigational sample was 205 patients with obstructive sleep apnoea at baseline and they were classified as non-POSA and POSA. Polygraphic registration was employed to compare the proportion of treatment responders between non-POSA and POSA groups at eight-week and one-year follow-ups. The treatment responder was defined as apnoea-hypopnoea index (AHI) <10 and/or ≥50% reduction in AHI.Results At the eight-week follow-up, the proportions of responders were 56% and 69% for the non-POSA and POSA groups (not significant), respectively. The responder proportions were increased to 68% and 77% for the two groups, respectively, at the one-year follow-up (not significant between the two groups). At the two follow-ups, there was no significant difference in absolute change in overall AHI between the two groups. However, the decrease in supine AHI was significantly greater in the POSA group, while the decrease in non-supine AHI was significantly greater in the non-POSA group.Conclusions The response rate for OA treatment did not differ between POSA and non-POSA groups. However, greater decreases in supine AHI and non-supine AHI were found among POSA and non-POSA patients, respectively.