Multimodal phenotypic labelling using drug-induced sleep endoscopy, awake nasendoscopy and computational fluid dynamics for the prediction of mandibular advancement device treatment outcome: a prospective study.

Mandibular advancement device (MAD) treatment outcome for obstructive sleep apnea (OSA) is variable and patient dependent. A global, clinically applicable predictive model is lacking. Our aim was to combine characteristics obtained during drug-induced sleep endoscopy (DISE), awake nasendoscopy, and computed tomography scan-based computational fluid dynamic (CFD) measurements in one multifactorial model, to explain MAD treatment outcome. A total of 100 patients with OSA were prospectively recruited and treated with a MAD at fixed 75% protrusion. In all, 72 underwent CFD analysis, DISE, and awake nasendoscopy at baseline in a blinded fashion and completed a 3-month follow-up polysomnography with a MAD. Treatment response was defined as a reduction in the apnea-hypopnea index (AHI) of ≥50% and deterioration as an increase of ≥10% during MAD treatment. To cope with missing data, multiple imputation with predictive mean matching was used. Multivariate logistic regression, adjusting for body mass index and baseline AHI, was used to combine all potential predictor variables. The strongest impact concerning odds ratios (ORs) was present for complete concentric palatal collapse (CCCp) during DISE on deterioration (OR 28.88, 95% confidence interval [CI] 1.18-704.35; p = 0.0391), followed by a C-shape versus an oval shape of the soft palate during wakefulness (OR 8.54, 95% CI 1.09-67.23; p = 0.0416) and tongue base collapse during DISE on response (OR 3.29, 95% CI 1.02-10.64; p = 0.0464). Both logistic regression models exhibited excellent and fair predictive accuracy. Our findings suggest DISE to be the most robust examination associated with MAD treatment outcome, with tongue base collapse as a predictor for successful MAD treatment and CCCp as an adverse DISE phenotype.

A promising concept of combination therapy for positional obstructive sleep apnea.

PURPOSE: The objective of this randomized controlled trial was to assess the additional effect of a chest-worn sleep position trainer (SPT) in patients with residual supine-dependent obstructive sleep apnea (sdOSA) under mandibular advancement device (MAD) therapy. METHODS: Baseline and follow-up polysomnography with MAD were performed. Twenty patients with sdOSA under MAD therapy underwent two consecutive randomized polysomnographies: one with SPT and one with combination of SPT + MAD. Data are presented as median (quartile 1, quartile 3). RESULTS: The SPT reduced the time spent in supine sleeping position compared to baseline and MAD therapy. Both MAD and SPT were individually effective in reducing the overall apnea/hypopnea index (AHI) significantly when compared to baseline from 20.8 (15.1; 33.6)/h at baseline to 11.0 (6.7; 13.8)/h and to 11.1 (3.5; 17.7)/h with MAD or SPT, respectively. The combination of SPT + MAD further reduced the overall AHI to 5.7 (3.6; 7.4), which was significantly lower than with MAD alone (p < 0.001) and SPT alone (p < 0.008), respectively. CONCLUSIONS: The results of this study indicate that combination of SPT + MAD leads to a higher therapeutic efficacy in patients with sdOSA under MAD therapy when compared to one of the treatment modalities alone.

Objective measurement of compliance during oral appliance therapy for sleep-disordered breathing.

BACKGROUND: Oral appliance (OA) therapy is increasingly prescribed as a non-continuous positive airway pressure treatment modality for sleep-disordered breathing (SDB). Although OA therapy is reported to be efficacious for the treatment of SDB, data on compliance remain limited to self-report. METHODS: In this 3-month prospective clinical trial, the main outcome was to assess the safety and feasibility of an objective measurement of compliance during OA therapy using an embedded microsensor thermometer with on-chip integrated readout electronics in 51 consecutive patients with an established diagnosis of SDB (AHI 18.0 ± 11.9/h; age 47 ± 10 y; BMI 26.6 ± 4.0 kg/m(2); men/women: 31/20). Patients were unaware of the purpose of the study. RESULTS: No microsensor-related adverse events were recorded. In addition, no problems were encountered during the readout of the compliance data. Out of 51 microsensors, one had a technical defect and was lost to follow-up. In this study, the overall objective mean rate of OA use was 6.6 ± 1.3 h per day with a regular OA users' rate of 82% at the 3-month follow-up. Statistical analysis revealed no significant differences between objective and self-reported OA compliance data in this study. Measurement of the objective OA compliance allowed us to calculate the mean disease alleviation (MDA) as the product of objective compliance and therapeutic efficacy. MDA serves as a measure of the overall therapeutic effectiveness, and turned out to be 51.1%. CONCLUSIONS: The results illustrate the safety and feasibility of objective measurement of OA compliance. The objective measurement of OA compliance allows for calculation of the MDA.

Sleep endoscopy with simulation bite for prediction of oral appliance treatment outcome.

The aim of this study was to assess the value of drug-induced sleep endoscopy (DISE) using a custom-made simulation bite in maximal comfortable protrusion (MCP) of the mandible, in the prediction of treatment outcome for obstructive sleep apnea (OSA) with a mandibular advancement device (MAD). Two hundred patients (74% male; age 46 ± 9 years; apnea-hypopnea index [AHI] 19 ± 13 h(-1) sleep; body mass index [BMI] 27 ± 4 kg m(-2) ) with sleep-disordered breathing underwent DISE with a simulation bite in MCP. One hundred and thirty-five patients with an established diagnosis of OSA commenced MAD treatment. The associations between the findings during DISE with simulation bite and treatment outcome were evaluated. Treatment response was defined as a reduction in AHI following MAD treatment of ≥ 50% compared to baseline. Overall MAD treatment response in the studied population was 69%. The results of this study demonstrated a statistically significant association between a positive effect of the simulation bite on the upper airway patency during DISE and treatment response with MAD (P < 0.01). The results of this study suggest that the use of a simulation bite in maximal comfortable protrusion (MCP) of the mandible, as used during DISE in patients with OSA, tends to be effective in predicting treatment response of MAD treatment.

Functional imaging improves patient selection for mandibular advancement device treatment outcome in sleep-disordered breathing: a prospective study.

STUDY OBJECTIVES: Mandibular advancement devices (MADs) are a noninvasive treatment option for patients with obstructive sleep apnea (OSA) and act by increasing the upper airway volume. However, the exact therapeutic mechanism of action remains unclear. The aim of this study was to assess MAD mechanisms using functional imaging that combines imaging techniques and computational fluid dynamics and assess associations with treatment outcome. METHODS: One hundred patients with OSA were prospectively included and treated with a custom-made MAD at a fixed 75% protrusion. A low-dose computed tomography scan was made with and without MADs for computational fluid dynamics analysis. Patients underwent a baseline and 3-month follow-up polysomnography to evaluate treatment efficacy. A reduction in apnea-hypopnea index ≥ 50% defined treatment response. RESULTS: Overall, 71 patients completed both 3-month follow-up polysomnography and low-dose computed tomography scan with computational fluid dynamics analysis. MAD treatment significantly reduced the apnea-hypopnea index (16.5 [10.4-23.6] events/h to 9.1 [3.9-16.4] events/h; P < .001, median [quartile 1-quartile 3]) and significantly increased the total upper airway volume (8.6 [5.4-12.8] cm3 vs 10.7 [6.4-15.4] cm3; P = .003), especially the velopharyngeal volume (2.1 [0.5-4.1] cm3 vs 3.3 [1.8-6.0] cm3; P < .001). However, subanalyses in responders and nonresponders only showed a significant increase in the total upper airway volume in responders, not in nonresponders. CONCLUSIONS: MAD acts by increasing the total upper airway volume, predominantly due to an increase in the velopharyngeal volume. Responders showed a significant increase in the total upper airway volume with MAD treatment, while there was no significant increase in nonresponders. Findings add evidence to implement functional imaging using computational fluid dynamics in routine MAD outcome prediction. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Predicting Therapeutic Outcome of Mandibular Advancement Device Treatment in Obstructive Sleep Apnea; URL: https://clinicaltrials.gov/ct2/show/NCT01532050; Identifier: NCT01532050. CITATION: Van Gaver H, Op de Beeck S, Dieltjens M, et al. Functional imaging improves patient selection for mandibular advancement device treatment outcome in sleep-disordered breathing: a prospective study. J Clin Sleep Med. 2022;18(3):739-750.

The relationship between specific nasopharyngoscopic features and treatment deterioration with mandibular advancement devices: a prospective study.

STUDY OBJECTIVES: The variable efficacy of mandibular advancement device (MAD) treatment necessitates both accessible and accurate methods for patient selection. However, the role of awake nasopharyngoscopy for this purpose remains dubious. We introduced an assessment method based on anatomical upper airway features during tidal breathing for nasopharyngoscopy. The current study aimed to relate these features to MAD treatment outcome. METHODS: One hundred patients diagnosed with obstructive sleep apnea were prospectively recruited for MAD treatment in a fixed 75% degree of maximal protrusion. Nasopharyngoscopic observations during Müller's maneuver and tidal breathing were recorded both with and without MAD. Treatment outcome, confirmed by 3-month follow-up polysomnography with MAD, was classified as (1) apnea-hypopnea index reduction ≥ 50%, (2) treatment apnea-hypopnea index < 5 events/h, and (3) ≥ 10% increase in apnea-hypopnea index compared with baseline (treatment deterioration). RESULTS: A complete dataset was obtained in 65 patients. After adjusting for baseline apnea-hypopnea index, body mass index, and supine dependency, the position of the soft palate (odds ratio, 4.0; 95% confidence interval, 1.3-11.8; P = .013) and crowding of the oropharynx (odds ratio, 7.7; 95% confidence interval, 1.4-41.4; P = .017) were related to treatment deterioration. Addition of both features significantly (P = .031) improved the accuracy of baseline models based on clinical measurements alone. Moreover, with the MAD in situ, a posteriorly located soft palate (odds ratio, 9.8; 95% confidence interval, 1.7-56.3; P = .010) and a posteriorly located tongue base (odds ratio, 7.4; 95% confidence interval, 1.5-35.9; P = .013) were associated with treatment deterioration. CONCLUSIONS: Awake nasopharyngoscopy might be a valuable office-based examination to exclude the risk of treatment deterioration and improve patient selection for MAD treatment. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Predicting Therapeutic Outcome of Mandibular Advancement Device Treatment in Obstructive Sleep Apnea (PROMAD); URL: https://clinicaltrials.gov/ct2/show/NCT01532050; Identifier: NCT01532050.

Drug-Induced Sleep Endoscopy Upper Airway Collapse Patterns and Maxillomandibular Advancement.

OBJECTIVES/HYPOTHESIS: To evaluate upper airway (UA) collapse patterns during drug-induced sleep endoscopy (DISE) and maxillomandibular advancement (MMA) surgery outcome, paying particular attention to the DISE phenotype complete concentric collapse at the level of the palate (CCCp). STUDY DESIGN: Prospective case series. METHODS: Nineteen patients diagnosed with obstructive sleep apnea (OSA) prospectively underwent mandibular advancement device (MAD) treatment followed by MMA surgery. UA collapse patterns were evaluated before and after MMA surgery. Baseline apnea-hypopnea index (AHI) was compared with AHI during MAD treatment and after MMA surgery. UA collapse patterns and the presence of baseline CCCp were assessed. AHI differences between patients with and without CCCp after MMA surgery were compared. RESULTS: In 14 patients, a full dataset was obtained: 8/6 (male/female), mean age = 51 ± 7 years, body mass index (BMI) = 25.6 ± 3.7 kg/m2 , and baseline AHI = 40.2 ± 25.6 per hour of sleep. MMA surgery reduced AHI to 9.9 ± 7.2 per hour of sleep (P = .0001). Eight patients benefited from additional AHI reduction compared to MAD treatment (P = .0113). Six out of 14 (43%) patients showed baseline CCCp. Baseline patient characteristics (age, BMI, and AHI) did not significantly differ between patients with and without CCCp. AHI was equally reduced after MMA, whether (P = .0145) or not (P = .0075) CCCp was present at baseline. All patients showed resolution of CCCp (P = .0159) during postoperative DISE. CONCLUSIONS: CCCp seems not to be a negative predictor for MMA surgery outcome measured by AHI reduction. Furthermore, MMA is likely to eliminate CCCp. Therefore, MMA might be a solution for OSA patients showing CCCp and broadens the perspective for personalized medicine and combination therapy. However, a large sample is required for definitive results. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:E268-E274, 2020.

Comparison of a custom-made and a thermoplastic oral appliance for the treatment of mild sleep apnea.

RATIONALE: The efficacy of immediate adaptation of mandibular advancement devices made of thermoplastic material as a treatment option for sleep-disordered breathing (SDB) has been demonstrated in clinical studies. To date, there have been no studies comparing the efficacy of such prefabricated devices with custom-made devices. OBJECTIVES: Our purpose was to compare the efficacy of both types of devices in patients with SDB. METHODS: A randomized controlled cross-over trial, comprising 4 months of treatment with a thermoplastic and a custom-made device, with a 1-month washout interval. MEASUREMENTS AND MAIN RESULTS: A total of 35 patients (29 males; age, 49 +/- 9 yr; apnea-hypopnea index [AHI], 13 +/- 11 events/h; body mass index, 28 +/- 4 kg/m(2)) completed the protocol. AHI was only reduced with the custom-made device (P = 0.005). In addition, this device reduced snoring to a greater extent than the thermoplastic device. The success rate was higher with the custom-made device (60 vs. 31%; P = 0.02). One-third of the patients demonstrated compliance failure with the thermoplastic device, mainly because of insufficient overnight retention. Total failure rate with the thermoplastic device was 69%, whereas the majority (63%) of these were successfully treated with the custom-made device. At the end of the study, 82% of the patients preferred the custom-made device, and 9% had no preference (P < 0.0001). CONCLUSIONS: In this study, a custom-made device turned out to be more effective than a thermoplastic device in the treatment of SDB. Our results suggest that the thermoplastic device cannot be recommended as a therapeutic option nor can it be used as a screening tool to find good candidates for mandibular advancement therapy.

Phenotypic Labelling Using Drug-Induced Sleep Endoscopy Improves Patient Selection for Mandibular Advancement Device Outcome: A Prospective Study.

STUDY OBJECTIVES: Mandibular advancement device (MAD) outcome varies between patients. We hypothesized that upper airway collapse sites, patterns, and degrees assessed during baseline drug-induced sleep endoscopy (DISE) affect MAD outcome. METHODS: One hundred patients with obstructive sleep apnea (OSA) were included and underwent baseline type 1 polysomnography. MAD was fitted intraorally at fixed 75% maximal protrusion. A total of 72 patients completed 3-month follow-up polysomnography and baseline DISE. Response was defined as apnea-hypopnea index (AHI) reduction ≥ 50%, deterioration as AHI increases during MAD treatment compared to baseline. RESULTS: Adjusting for baseline AHI and body mass index, patients with tongue base collapse showed 3.69 higher odds (1.27-10.73; P = .0128) for response. Complete concentric collapse at the level of the palate (5.32 [1.21-23.28]; P = .0234) and complete laterolateral oropharyngeal collapse (6.62 [1.14-38.34]; P = .0330) related to deterioration. Results for tongue base collapse and complete concentric collapse at the level of the palate were confirmed in the moderate to severe OSA subgroup. Applying these results to this selected subgroup increased response rate with 54% and decreased deterioration rate with 53%. These results were confirmed using other response and deterioration definitions. CONCLUSIONS: Three baseline DISE phenotypes identified during drug-induced sleep were significantly related to MAD treatment outcome: one beneficial, tongue base collapse, and two adverse, complete concentric collapse at the level of the palate and complete laterolateral oropharyngeal collapse. If confirmed in future prospective studies, these results could guide patient selection for MAD outcome. CLINICAL TRIAL REGISTRATION: This prospective clinical trial (PROMAD) was registered on Clinicaltrials.gov with identifier: NCT01532050. CITATION: Op de Beeck S, Dieltjens M, Verbruggen AE, Vroegop AV, Wouters K, Hamans E, Willemen M, Verbraecken J, De Backer WA, Van de Heyning PH, Braem MJ, Vanderveken OM. Phenotypic labelling using drug-induced sleep endoscopy improves patient selection for mandibular advancement device outcome: a prospective study. J Clin Sleep Med. 2019;15(8):1089-1099.

Remotely Controlled Mandibular Positioning During Drug-Induced Sleep Endoscopy Toward Mandibular Advancement Device Therapy: Feasibility and Protocol.

STUDY OBJECTIVES: The potential of a remotely controlled mandibular positioner (RCMP) during sleep studies in individual patients suffering from obstructive sleep apnea (OSA) for the determination of the effective target protrusive position (ETPP) of the mandible has been demonstrated. The research goal of this study was to assess the feasibility of the application of RCMP during drug-induced sleep endoscopy (DISE) for the determination of ETPP. METHODS: Ten patients in whom OSA was diagnosed (50% male; age 54 ± 9.5 years; body mass index 26.9 ± 2.1 kg/m2; apnea-hypopnea index 28.4 ± 13.2 events/h) were enrolled prospectively. Dental RCMP trays were fitted during wakefulness. Maximal protrusion and edge-to-edge positions were measured. Upper airway collapsibility was scored during DISE, including full-range mandibular RCMP titration within 45 minutes. ETPP was defined as the mandibular threshold protrusion yielding a stable upper airway in the absence of snoring, oxygen desaturation and apneas. RESULTS: RCMP trays were retentive and no adverse reactions occurred. RCMP was fitted intraorally prior to sedation with maxillary and mandibular trays in edge-to-edge position. Upon sedation, progressive protrusion was performed followed by reversed titration until ETPP was noted. In one patient ETPP was not within the mandibular range of motion. In one patient RCMP needed to be removed because of clenching. CONCLUSIONS: The results of this study illustrate that it is feasible to use RCMP during DISE and to determine ETPP within 45 minutes. Comparative research with polysomnography would be useful to further validate the therapy outcome upon use of RCMP during DISE.

Improving vestibular evoked myogenic potential reliability by using a blood pressure manometer.

OBJECTIVE/HYPOTHESIS: To improve the reliability of vestibular evoked myogenic potentials (VEMP), we propose a feedback method making use of a readily available blood pressure manometer with inflatable cuff to control the sternocleidomastoid muscle (SCM) contraction. STUDY DESIGN: Prospective study. MATERIALS AND METHODS: The feedback method for SCM contraction consisted of subjects pushing with their jaw against the hand-held inflated cuff to generate a specified cuff pressure. This pressure level was monitored by subject and investigator. First, we tested in a group of healthy subjects whether there was a learning or fatigue effect during four successive SCM contraction runs when making use of the feedback method. Then, we investigated the mean rectified voltage (MRV) values of the SCM. Next, we examined the hypothesis that the MRV values of the SCM contraction measured before and simultaneously with the VEMP test were equal when using this feedback method. Finally, we compared the VEMP amplitude variability in two circumstances: with and without the feedback method. RESULTS: There was no learning or fatigue effect, and the MRV values measured before the VEMP were not significantly different from those measured during the VEMP test. The VEMP amplitude variability was significantly lower when applying the feedback method than when no feedback method was used. CONCLUSION: This feedback method improves significantly the VEMP amplitude reliability.

The Use of Remotely Controlled Mandibular Positioner as a Predictive Screening Tool for Mandibular Advancement Device Therapy in Patients with Obstructive Sleep Apnea through Single-Night Progressive Titration of the Mandible: A Systematic Review.

STUDY OBJECTIVES: To perform a review of the current evidence regarding the use of a remotely controlled mandibular positioner (RCMP) and to analyze the efficacy of RCMP as a predictive selection tool in the treatment of obstructive sleep apnea (OSA) with oral appliances that protrude the mandible (OAm), exclusively relying on single-night RCMP titration. METHODS: An extensive literature search is performed through PubMed.com, Thecochranelibrary.com (CENTRAL only), Embase.com, and recent conference meeting abstracts in the field. RESULTS: A total of 254 OSA patients from four full-text articles and 5 conference meeting abstracts contribute data to the review. Criteria for successful RCMP test and success with OAm differed between studies. Study populations were not fully comparable due to range-difference in baseline apneahypopnea index (AHI). However, in all studies elimination of airway obstruction events during sleep by RCMP titration predicted OAm therapy success by the determination of the most effective target protrusive position (ETPP). A statistically significant association is found between mean AHI predicted outcome with RCMP and treatment outcome with OAm on polysomnographic or portable sleep monitoring evaluation (p < 0.05). CONCLUSIONS: The existing evidence regarding the use of RCMP in patients with OSA indicates that it might be possible to protrude the mandible progressively during sleep under poly(somno)graphic observation by RCMP until respiratory events are eliminated without disturbing sleep or arousing the patient. ETPP as measured by the use of RCMP was significantly associated with success of OAm therapy in the reported studies. RCMP might be a promising instrument for predicting OAm treatment outcome and targeting the degree of mandibular advancement needed.

Restricted sedation and absence of cognitive impairments after administration of intranasal scopolamine.

INTRODUCTION: Space motion sickness in astronauts during spaceflight causes significant discomfort, which might impede their functionality. Pharmacological treatment has been mainly restricted to promethazine. Transdermal and oral scopolamine have also been used in space; however, their use was reduced due to unpredictable effectiveness and side effects. Recently, intranasal scopolamine administration has gained much interest, since this route ensures fast and reliable absorption with a decreased incidence of undesirable side effects. The aim of this study was to evaluate the effect of intranasal scopolamine on cognitive performance and to determine its side effects. METHODS: This double-blind, placebo controlled, repeated measures study evaluated vigilant attention, short-term memory, implicit memory and working memory. Side effects were reported on a 22-item questionnaire and sleepiness was assessed by the Karolinska, Stanford and Epworth Sleepiness Scales. RESULTS: Scopolamine had no effect on cognitive function. Only the Karolinska score was significantly increased for scopolamine compared to placebo. Participants reported a dry mouth and dizziness after receiving scopolamine. DISCUSSION: Results show that intranasal scopolamine did not impair cognitive performance. Intranasal scopolamine might be a good alternative to promethazine for the alleviation of space motion sickness, since the agent has minimal sedative effects and does not hamper cognitive performance.

Determinants of Objective Compliance During Oral Appliance Therapy in Patients With Sleep-Disordered Breathing: A Prospective Clinical Trial.

IMPORTANCE: The main reported reasons for discontinuation of oral appliance therapy for sleep-disordered breathing (SDB) are the presence of self-perceived adverse effects and self-appreciated lack of efficacy. However, these conclusions rely only on subjective compliance data. OBJECTIVE: To determine which parameters are correlated with objectively measured data on compliance with oral appliance therapy. DESIGN, SETTING, AND PARTICIPANTS: For 51 outpatients with SDB, a prospective clinical trial using oral appliance therapy was conducted at Antwerp University Hospital from February 7, 2011, to October 8, 2013 (38 [75%] males; mean [SD] age, 49.3 [9.0] years; mean [SD] apnea-hypopnea index, 14.9 [9.3] events per hour of sleep; mean [SD] body mass index [calculated as weight in kilograms divided by height in meters squared], 26.3 [2.8]). Analysis was performed November 5, 2014. INTERVENTION: Oral appliance therapy with a custom-made, titratrable mandibular advancement device (OAm). MAIN OUTCOMES AND MEASURES: Possible correlations were assessed between objective compliance and patients' anthropometric characteristics, polysomnographic parameters, and answers to 3 subjective questionnaires (the visual analog scale for snoring, the Epworth Sleepiness Scale, and an adverse effects questionnaire). RESULTS: Median oral appliance use was 6.4 hours per night (range, 4.7-7.2 hours per night) at the 3-month follow-up. None of the anthropometric and polysomnographic parameters were correlated with compliance. No correlation was found between objective compliance and reports of excessive daytime sleepiness. However, a significant inverse correlation was found between objective compliance and posttreatment visual analog scale values for snoring (P = .006; ρ = ­.40). In addition, objective compliance was correlated significantly with a more pronounced decrease in socially disturbing snoring (P = .005; ρ = 0.39). The presence of dry mouth was the only adverse effect that was negatively correlated with objective compliance at the 3-month follow-up (P < .05; ρ = ­.31). CONCLUSIONS AND RELEVANCE: Neither the anthropometric and polysomnographic parameters nor reports of excessive daytime sleepiness correlated with compliance during oral appliance therapy. The 2 parameters that were correlated with higher objective compliance during oral appliance therapy were a more pronounced decrease in snoring and the presence of dry mouth during treatment. TRIAL REGISTRATION: clinicaltrials.gov Identifiers: NCT01284881 and NCT01532050.

Pilot study of a novel mandibular advancement device for the control of snoring.

OBJECTIVE: Mandibular advancement devices (MADs) have been introduced as a conservative, non-invasive treatment for socially disturbing snoring and mild obstructive sleep apnea (OSA). A prospective, non-randomized pilot study was conducted to investigate the efficacy, feasibility, side-effects and compliance of Somnoguard, an immediately intraorally adaptable MAD made from thermoplastic material. MATERIAL AND METHODS: Twenty consecutive heavy snorers with a respiratory disturbance index of <20 events/h were prospectively selected. Prior to the adaptation of the appliance, ambulatory polygraphy was carried out without a MAD. After a 1-month habituation period, a polygraphic evaluation was carried out with the device. Treatment success was defined as a reduction in the apnea-hypopnea index (AHI) of at least 50%. RESULTS: The results indicated a success rate of 65%. The AHI decreased from 8.4 +/- 2.9 events/h at baseline to 3.9 +/- 1.8 events/h with the device (p = 0.001). At 1-month follow-up, significant reductions in the snoring index (p < 0.001) and the Epworth Sleepiness Scale (ESS) score (p = 0.036) were noted. At 6-month follow-up, similar results were achieved, with significant drops in the snoring index (p = 0.025) and ESS score (p = 0.033). CONCLUSION: We conclude that immediate intraoral adaptation of a low-cost fabricated "one-size-only" MAD is a feasible and well-tolerated treatment for snoring and mild OSA. Further research is needed to evaluate this thermoplastic appliance as a strategy to "screen" the efficacy of MAD treatment in the individual patient with a less expensive appliance before constructing a more expensive custom-made MAD.

Prevalence and clinical significance of supine-dependent obstructive sleep apnea in patients using oral appliance therapy.

STUDY OBJECTIVE: The prevalence of supine-dependent obstructive sleep apnea (sdOSA) in a general population ranges from 20% to 60%, depending on the criteria used. Currently, the prevalence and evolution of sdOSA once oral appliance therapy with a mandibular advancement device (OAm) has started is unknown. In addition, literature on the correlation between sdOSA and treatment success with OAm is not unequivocal. The first purpose of this study was to assess the prevalence of sdOSA before and under OAm therapy. Second, the conversion rate from non-sdOSA to sdOSA during OAm therapy was evaluated. The third and final goal was to analyze the correlation between sdOSA and treatment success with OAm therapy in the patient population. METHODS: Two hundred thirty-seven consecutive patients (age 48 ± 9 years; male/female ratio 173/64; AHI 20.1 ± 14.7 events/h; BMI 27.2 ± 4.3 kg/m(2)) starting OAm therapy were included. RESULTS: The prevalence of sdOSA before the start of OAm therapy, ranged from 27.0% to 67.5%. The prevalence of residual sdOSA under OAm therapy in this study ranged from 17.5% to 33.9%. Second, the conversion rate from non-sdOSA to sdOSA ranged from 23.0% to 37.5%. Third, the presence of sdOSA at baseline was not a significant factor for treatment success with OAm therapy. CONCLUSIONS: The results of this study indicate that the prevalence of sdOSA before and under OAm therapy is relatively high. One-third of patients shift from non-sdOSA to sdOSA. Finally, treatment success for OAm therapy was not significantly correlated with the presence of sdOSA at baseline.

Drug-induced sleep endoscopy in sleep-disordered breathing: report on 1,249 cases.

OBJECTIVES/HYPOTHESIS: To describe upper airway (UA) collapse patterns during drug-induced sleep endoscopy (DISE) in a large cohort of patients with sleep-disordered breathing (SDB) and to assess associations with anthropometric and polysomnographic parameters. STUDY DESIGN: Observational study. METHODS: A total of 1,249 patients [age 47 ± 10 y; apnea-hypopnea index (AHI) 18.9 ± 15.3/h; body mass index (BMI) 27.2 ± 3.7 kg/m(2)] underwent polysomnography and DISE. DISE findings were categorized to the following UA levels: palate, oropharynx, tongue base, and hypopharynx. The degree of collapse was reported as complete, partial, or none. The pattern of the obstruction was described as anteroposterior, lateral, or concentric. Associations between DISE findings and anthropometric and polysomnographic parameters were analyzed. RESULTS: Palatal collapse was seen most frequently (81%). Multilevel collapse was noted in 68.2% of all patients. The most frequently observed multilevel collapse pattern was a combination of palatal and tongue base collapse (25.5%). Palatal collapse was seen most frequently (81%). The prevalence of complete collapse, multilevel collapse, and hypopharyngeal collapse increased with increasing severity of obstructive sleep apnea (OSA). Multilevel and complete collapse were more prevalent in obese patients and in those with more severe OSA. Both higher BMI and AHI values were associated with a higher probability of complete concentric palatal collapse. CONCLUSION: The current study provides an overview of UA collapse patterns in a large cohort of SDB patients who underwent DISE. The associations found in this study may indicate that UA collapse patterns observed during DISE cannot be fully explained by selected baseline polysomnographic and anthropometric characteristics.

Observer variation in drug-induced sleep endoscopy: experienced versus nonexperienced ear, nose, and throat surgeons.

STUDY OBJECTIVE: To determine variations in interobserver and intraobserver agreement of drug-induced sleep endoscopy (DISE) in a cohort of experienced versus nonexperienced ear, nose, and throat (ENT) surgeons. DESIGN: Prospective, blinded agreement study. SETTING: Ninety-seven ENT surgeons (90 nonexperienced with DISE; seven experienced) observed six different DISE videos and were asked to score the upper airway (UA) level (palate, oropharynx, tongue base, hypopharynx, epiglottis), direction (anteroposterior, concentric, lateral), and degree of collapse (none; partial or complete collapse). Findings were collected and analyzed, determining interobserver and intraobserver agreement [overall agreement (OA), specific agreement (SA)] and kappa values per UA level. MEASUREMENT AND RESULTS: In the nonexperienced group, overall interobserver agreement on presence of tongue base collapse (OA = 0.63; kappa = 0.33) was followed by the agreement on epiglottis (OA = 0.57; kappa = 0.23) and oropharynx collapse (OA = 0.45; kappa = 0.09). Low overall interobserver agreement in this group was found for hypopharyngeal collapse (OA = 0.33; kappa = 0.08). A similar ranking was found for degree of collapse. For direction of collapse, high interobserver agreement was found for the palate (OA = 0.57; kappa = 0.16). Among the experienced observers, overall interobserver agreement was highest for presence of tongue base collapse (OA = 0.93; kappa = 0.71), followed by collapse of the palate (OA = 0.80; kappa = 0.51). In this group, lowest agreement was also found for hypopharyngeal collapse (OA = 0.47; kappa = 0.03). Interob-server agreement on direction of collapse was highest for epiglottis collapse (OA = 0.97; kappa = 0.97). Concerning the degree of collapse, highest agreement was found for degree of oropharyngeal collapse (OA = 0.82; kappa = 0.66). Among the experienced observers a statistically significant higher interobserver agreement was obtained for presence, direction, and degree of oropharyngeal collapse, as well as for presence of tongue base collapse and degree of epiglottis collapse. Among the nonexperienced observers, high intraobserver agreement was found in particular for tongue base and epiglottis collapse. Among the experienced observers, high agreement was found for all levels but to a lesser extent for hypopharyngeal collapse. Intraobserver agreement was statistically significantly higher in the experienced group, for all UA levels expect for the hypopharynx. CONCLUSION: This study indicates that both interobserver and intraobserver agreement was higher in experienced versus nonexperienced ENT surgeons. Agreement ranged from poor to excellent in both groups. The current results suggest that experience in performing DISE is necessary to obtain reliable observations.

Effects of vertical opening on pharyngeal dimensions in patients with obstructive sleep apnoea.

BACKGROUND: It is still subject to controversy if an increased vertical opening (VO) is beneficial in oral appliance therapy for the treatment of obstructive sleep apnoea. Each oral appliance has a given thickness causing VO. Therefore, evaluation of the effects of the amount of VO on pharyngeal dimensions is mandatory. METHODS: The effects of VO on the cross-sectional area of the upper airway at the level of the tongue base during sleep endoscopy were scored and categorised. RESULTS: The figures demonstrate the possible effects of VO on pharyngeal collapse relative to the baseline cross-sectional area and the maximal comfortable protrusion of the mandible. Thirty-two patients (80%) showed an adverse effect of VO (Fig. 1), one patient (2.5%) had a positive effect (Fig. 2), and seven patients (17.5%) demonstrated an indifferent effect (Fig. 3). CONCLUSION: Based on literature, the effect of VO on pharyngeal collapse is unclear and the therapeutic impact of VO is not determined. The results of the present study indicate that the effect of VO on the degree of pharyngeal collapse as assessed during sleep endoscopy tends to be adverse, causing an increase in collapsibility in the majority of patients.