The effect of mandibular advancement on upper airway structure in obstructive sleep apnoea

The effect of mandibular advancement on pharyngeal airway space in patients with oral squamous cell carcinoma: A monocentric prospective study with computed tomography

OBJECTIVES

The presented study aimed to evaluate the effect of mandibular protrusion with a temporarily applied mandibular advancement device (MAD) on the posterior airway space and to determine a reliable metric constant based on a three-dimensional computed tomography (CT) evaluation.

MATERIALS AND METHODS

The study population consisted of patients with oral squamous cell carcinoma who were treated at least six months prior to the follow-up CT in supine position. Each patient received an individually adjusted MAD that was temporarily applied with three different protrusion distances (P0 = 0 mm, P4 = 4 mm, and P8 = 8 mm) during follow-up CT. The open-source software Slicer was used to calculate three parameters: minimum cross-sectional area (minCSA), mean cross-sectional area (meanCSA), and volume.

RESULTS

The results showed a significant increase for all three parameters. The minCSA increased as follows: P0 = 236.4 mm2 ± 192.2; P4 = 309.2 mm2 ± 235.4; and P8 = 430.6 mm2 ± 265.3. The meanCSA increased significantly (p < 0.001) in all protrusion steps and all parts of the pharynx. The volume changed as follows: P0 = 24.0 cm3 ± 5.0; P4 = 29.6 cm3 ± 18.1; and P8 = 33.6 cm3 ± 19.0. The minCSA increased by 24.9 mm2 ± 13.0 per millimeter mandibular protrusion. CONCLUSION AND CLINICAL RELEVANCE: The results are interesting for both conservative and surgical therapy and could find future application in dental, orthodontic, and combined oral surgical therapy. With the results of this study, surgeons and dentists may better predict the change of PAS parameter in order to better prepare for orthognathic surgery. They also could ensure the right protrusion distance for mandibular advancement devices in the case of obstructive sleep apnea.

Impact of tumor localization and choice of microvascular flap on posterior airway changes following ablative surgery in primary oral squamous cell carcinoma: A monocentric cross-sectional study

BACKGROUND

The aim of this study was to determine the influence of intraoral reconstructions following oral squamous cell carcinoma (OSCC) resection with a free microvascular flap on the posterior airway space (PAS) and to correlate these results with the potential risk of developing an obstructive sleep apnea syndrome (OSAS).

MATERIALS AND METHODS

Only primary OSCC cases of the tongue or floor of the mouth which were operated and reconstructed. The PAS displayed in computed tomography (CT) scans at three time points were analyzed: t0 = preoperative, t1 = first postoperative CT, and t2 = most recent situation. The following three PAS parameters were calculated: minimum cross-sectional area (minCSA), mean cross-sectional area (meanCSA), and volume.

RESULTS

MinCSA increased from t0 to t2: t0 = 86.9 cm2 (0.0 - 251.8), t1 = 106.6 cm2 (1.0 - 483.4), and t2 = 124.8 cm2 (0.5 - 395.6). MeanCSA increased from t0 to t2: t0 = 225.1 cm2 (79.0 - 500.2), t1 = 247.8 cm2 (102.8 - 674.3), and t2 = 272.2 cm2 (92.2 - 668.4). The volume increased from t0 to t2: t0 = 21.5 cm3 (8.0 - 63.2), t1 = 24.1 cm3 (9.6 - 67.3), and t2 = 26.9 cm3 (6.2 - 67.4).

CONCLUSIONS

Posterior airway space PAS values became higher than preoperatively. In particular, flap type had a significant influence on the three PAS parameters.

Drug induced sleep endoscopy and simultaneous polysomnography to predict the effectiveness of mandibular advancement device in obstructive sleep apnea treatment

PURPOSES

To evaluate whether mandibular advancement device therapy is recommended in patients affected by obstructive sleep apnea.

METHODS

In order to predict oral appliances therapy response, drug induced sleep endoscopy with cardio-respiratory polygraphy and mandibular advancement device simulator was carried out. Patients in which upper airway obstruction was resolved on all levels and AHI was normalized (< 5/h), were referred for oral appliance therapy. At 5 months follow up, a cardio-respiratory polygraphy with MAD was performed.

RESULTS

36 patients who have evidence of resolution of UA collapse and AHI below 5 events per hour, were referred for MAD therapy. At follow up, the mean AHI decreased from 29.1 ± 13.1 to 3.3/h ± 1.9 (p < 0.001). All the patients were responders.

CONCLUSION

Combining the evaluation of drug induced sleep endoscopy and cardio-respiratory polygraphy data simultaneously during mandibular protrusion, has the potential to be a useful tool for prediction of MAD therapy response.

Pilot analysis of magnetic resonance imaging-based contributors to patient-centred optimization of mandibular advancement devices in obstructive sleep apnea

Mandibular advancement devices are an effective treatment option for obstructive sleep apnea. While their efficacy depends on the degree of mandibular protrusion, other contributing factors influencing the optimal outcome are not fully understood. This magnetic resonance imaging-based pilot study aimed at investigating whether there are promising planimetric parameters that may be related to the optimal therapeutic position. A second aim was to assess possible sex-specific differences. Planimetric data from magnetic resonance imaging taken in the habitual position and four protrusion grades were collected from 11 female and 14 male patients with obstructive sleep apnea (age 45 ± 13.3 years; body mass index 27.6 ± 4.5 kg m-2). Data were correlated with outcome as substantiated by polygraphic data obtained at the habitual position and at each of two protrusion positions considered to reveal the highest treatment effect. Protrusion degree and lateral widening of the retropalatal region correlated most strongly (R = 0.56, p < 0.001). Relationships between planimetric data and treatment success were most pronounced at the level of the smallest cross-section, expressed, for example, by a correlation between oxygen desaturation index and lateral diameter (R = -0.4, p = 0.012). Female participants appeared to show improved polygraphic values at a lower protrusion degree than males. Data from magnetic resonance imaging allow for a comprehensive analysis combining insights from planimetric velopharyngeal measurements at different individual protrusion grades and correlation with outcome. The results of this pilot work encourage further evaluation in large-scale studies. These should focus on the velopharyngeal region and investigate the influence of sex more closely.

The role of orthodontists in the multidisciplinary management of obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) is a complex disorder characterized by interruptions in breathing during sleep, leading to a range of adverse outcomes from reduced quality of life to serious health risks, including cardiovascular diseases and increased mortality.

MAIN BODY

This manuscript reviews the orthodontists' essential role in the multidisciplinary healthcare team tasked with managing OSA. It particularly highlights critical orthodontic interventions, such as surgical-orthodontic maxillomandibular advancement (MMA), mandibular advancement appliances (MAAs), and rapid maxillary expansion (RME). These interventions are pivotal in modifying craniofacial structures to enhance airway patency. The importance of conducting a thorough airway analysis is underscored, assessing the complete anatomical and functional factors contributing to airway obstruction.

CONCLUSION

The paper calls for increased collaborative research efforts to develop standardized, evidence-based orthodontic procedures for effectively managing OSA, aiming to improve patient outcomes through specialized, tailored interventions.

Kinematical Effects of a Mandibular Advancement Occlusal Splint on Running until Exhaustion at Severe Intensity

The effects of occlusal splints on sport performance have already been studied, although their biomechanical impacts are often overlooked. We investigated the kinematical changes during running until exhaustion at severe intensity while wearing a mandibular advancement occlusal splint. Twelve trained runners completed (i) an incremental protocol on a track to determine their velocity corresponding to maximal oxygen uptake and (ii) two trials of square wave transition exercises at their velocity corresponding to maximal oxygen until exhaustion, wearing two occlusal splints (without and with mandibular advancement). Running kinematics were compared within laps performed during the square wave transition exercises and between splint conditions. The mandibular advancement occlusal splint increased the running distance covered (~1663 ± 402 vs. 1540 ± 397 m, p = 0.03), along with a noticeable lap effect in decreasing stride frequency (p = 0.04) and increasing stride length (p = 0.03) and duty factor (p < 0.001). No spatiotemporal differences were observed between splints, except for improved balance foot contact times in the mandibular advancement condition. An increased knee flexion angle at initial contact (p = 0.017) was noted along laps in the non-advancement condition, despite the fact that no differences between splints were found. Running patterns mainly shifted within laps rather than between conditions, indicating that a mandibular advancement occlusal splint had a trivial kinematical effect.

Comparison of monoblock and twinblock mandibular advancement devices in patiens with obstructive sleep apnea and temporomandibular disorder: effects on airway volume, polysomnography parameters, and sleepiness scale scores

PURPOSE

This study aimed to compare the effects of two different mandibular advancement devices on the upper airway volume, polysomnographic parameters, and sleepiness scale scores in patients with obstructive sleep apnea and Temporomandibular disorders (TMD).

MATERIALS AND METHODS

Monoblock and twinblock mandibular advancement devices were applied to patients with obstructive sleep apnea syndrome for 3 months separated by a wash-out period of 2 weeks. Research Diagnostic Criteria for TMD (RDC/TMD), Polysomnographic parameters and cone-beam computed tomography findings were recorded before and after the use of the mandibular advancement devices. A three-dimensional analysis of the airway was then performed.

RESULTS

The use of the monoblock device significantly increased the upper airway volume compared with the use of the twinblock device (p = 0.032). The polysomnographic parameters similarly improved with the use of the twin-block and monoblock devices. The significant reduction in TMD symptoms was observed.

CONCLUSION

The use of the monoblock device increased the retropalatal airway volume. This volume increase may be attributed to the fact that the design of the monoblock device allows less mandibular movement than does that of the twinblock device. Indicates the potential benefits of MADS treatment in alleviating TMD-related issues.

CLINICAL SIGNIFICANCE

Monoblock MADs have improved effects on respiratory parameters and upper airway dimensions in patients with OSA and mild to moderate TMD.

Exploring hypoglossal nerve stimulation therapy for obstructive sleep apnea: A comprehensive review of clinical and physiological upper airway outcomes

Obstructive sleep apnea (OSA) is a chronic disorder characterized by recurrent episodes of upper airway collapse during sleep, which can lead to serious health issues like cardiovascular disease and neurocognitive impairments. While positive airway pressure serves as the standard treatment, intolerance in some individuals necessitates exploration of alternative therapies. Hypoglossal nerve stimulation (HGNS) promises to mitigate OSA morbidity by stimulating the tongue muscles to maintain airway patency. However, its effectiveness varies, prompting research for optimization. This review summarizes the effects of HGNS on upper airway obstruction from human and animal studies. It examines physiological responses including critical closing pressure, maximal airflow, nasal and upper airway resistance, compliance, stiffness, and geometry. Interactions among these parameters and discrepant findings in animal and human studies are explored. Additionally, the review summarizes the impact of HGNS on established OSA metrics, such as the apnea-hypopnea index, oxygen desaturation index, and sleep arousals. Various therapeutic modalities, including selective unilateral or bilateral HGNS, targeted unilateral HGNS, and whole unilateral or bilateral HGNS, are discussed. This review consolidates our understanding of HGNS mechanisms, fostering exploration of under-investigated outcomes and approaches to drive advancements in HGNS therapy.

State-Dependent Biomechanical Behavior of Oropharyngeal Structures in Apneic and Control Subjects: A Proof-of-Concept Study

Rationale: Apneic individuals have reduced airway caliber during sleep. The biomechanical changes in upper airway anatomy contributing to this airway narrowing are largely unknown. Objectives: We sought to investigate the state-dependent (wake vs. sleep) biomechanical behavior of the upper airway soft-tissue and craniofacial structures. Methods: Upper airway magnetic resonance imaging was performed in 15 sleep-deprived control subjects (apnea-hypopnea index, <5; 0.3 ± 0.5 events per hour) and 12 sleep-deprived apneic subjects (apnea-hypopnea index, ⩾5; 35.2 ± 18.1 events per hour) during wake and sleep and analyzed for airway measures and soft-tissue/mandibular movement. Results: In the retropalatal region, control subjects showed sleep-dependent reductions (P ⩽ 0.037) in average cross-sectional airway area (CSA), minimum CSA, and anteroposterior and lateral dimensions. Apneic subjects showed sleep-dependent reductions (P ⩽ 0.002) in average CSA, minimum CSA, and anteroposterior and lateral dimensions. In the retroglossal region, control subjects had no sleep-dependent airway reductions. However, apneic subjects had sleep-dependent reductions in minimal CSA (P = 0.001) and lateral dimensions (P = 0.014). Control subjects only showed sleep-dependent posterior movement of the anterior-inferior tongue octant (P = 0.039), whereas apneic subjects showed posterior movement of the soft palate (P = 0.006) and all tongue octants (P ⩽ 0.012). Sleep-dependent medial movement of the lateral walls was seen at the retropalatal minimum level (P = 0.013) in control subjects and at the retropalatal and retroglossal minimum levels (P ⩽ 0.017) in apneic subjects. There was posterior movement of the mandible in apneic subjects (P ⩽ 0.017). Conclusions: During sleep, control and apneic subjects showed reductions in retropalatal airway caliber, but only the apneic subjects showed retroglossal airway narrowing. Reductions in anteroposterior and lateral airway dimensions were primarily due to posterior soft palate, tongue and mandibular movement and to medial lateral wall movement. These data provide important initial insights into obstructive sleep apnea pathogenesis.

Precision medicine approaches in obstructive sleep apnoea: The role of dentist-sleep physician partnerships

Obstructive Sleep Apnoea (OSA) is a common heterogenous sleep disorder that is associated with a wide range of comorbidities and consequences, including the development of neurocognitive and cardiometabolic disorders. The heterogeneity of OSA necessitates a precision medicine approach to accurately diagnose this condition and to effectively manage patients. One of the primary models of precision medicine is described by the P4 approach of predicting those who are susceptible to disease, preventing the occurrence of disease, personalizing treatment, and encouraging patients to participate in their individual healthcare journey. Recent advances in oral appliance therapy and OSA monitoring techniques have fostered an exciting opportunity for enhanced collaboration between dentists and sleep physicians to optimize OSA precision medicine care. This review aims to discuss the sources of heterogeneity among OSA patients, provide an overview of the growing applications of oral appliance therapy and tailored monitoring programs for OSA that are shifting treatment to a more personalized and participatory model of care, and outline the pivotal role of dentists in managing patients with OSA.

A systematic review on 4D images of the upper airway in patients with OSA

AIM-BACKGROUND

In the treatment of obstructive sleep apnoea (OSA), oral appliances are now being recognized as a valuable alternative to continuous positive airway pressure (CPAP). Various static imaging techniques of the upper airways allow for assessment of bone and soft tissue structures. However, static images do not capture dynamic airway characteristics. The aim of this paper was to review 4D imaging techniques in patients with OSA.

METHODS

PubMed/MEDLINE, Web of Science and Embase were systematically searched for studies published before June 2022. The review was compliant with the PRISMA guidelines. The quality of each eligible study was critically evaluated by all four authors independently. Four unique articles with qualitative analyses were retrieved. All included studies had a clear objective/aim, an appropriate endpoint and sufficiently described eligibility criteria.

RESULTS

With dynamic imaging (4D) evaluation of the upper airway, the incidence of upper airway collapsibility due to use of a mandibular advancement device (MAD) was reduced, extraluminal tissue pressure was decreased and the space in the upper airway was increased, notably in the retropalatal and retroglossal areas of the airway. These findings suggest that MADs may be effective for OSA regardless of whether or not the obstruction site is in the velopharynx or oropharynx. However, further investigation of dynamic changes in the upper airway is required to explain the efficacy of OSA treatment and the underlying mechanisms.

Comparative analysis of two custom-made mandibular advancement devices with varied designs for treating moderate to severe obstructive sleep apnea

INTRODUCTION

Custom-made titratable mandibular advancement device (MAD) treatment can nowadays be considered a promising first-line treatment in patients with mild to severe obstructive sleep apnea (OSA). Specific manufacturing designs and titration mechanisms of MAD are on the market, characterized by their titration approach, vertical opening, and materials selection. The wing-designed MAD (SomnoDent® Flex™, SomnoMed Ltd, Sydney, Australia) has a lateral screw mechanism to advance the lower jaw in incremental steps of 0.1 up to 6.0 mm. The newer uniquely designed custom-made MAD with passive mouth closing (SomnoDent® Avant™ SomnoMed Ltd, Sydney, Australia) has a frontal exchangeable advancement strap of fixed lengths as a specific titration mechanism, all supporting freedom of lateral movement. We aimed to assess the associations between the type of MAD prescribed and OSA treatment outcome.

METHODS

Data from 209 patients (165 male, mean age 53.9 (±10.9) years, median baseline BMI and AHI 27.02 [24.8; 29.7] kg/m2 and 22.8 [17.7; 31.6]/hour sleep, respectively) were collected. Of this cohort, 91 patients with the traditional, wing-based SomnoDent® Flex™ and 118 patients with SomnoDent® Avant™. All patients were diagnosed with a type 1 polysomnography demonstrating moderate to severe OSA (15 ≤ AHI ≤65 per hour sleep). The selected MAD was fitted in the so-called maximal comfortable protrusion. After 3 months of subjective titration until resolution of subjective symptoms and/or achieving physical limits, a checkup with validated home sleep monitoring was conducted. Treatment success was defined as "AHI reduction ≥50% with MAD compared to baseline AHI and AHI with MAD <10 events per hour".

RESULTS

These real-world data set showed that 67% of patients achieved treatment success, with a statistically significant reduction in AHI from 22.8 [17.7; 31.6] to 7.45 [3.4; 15.0]/h sleep. The SomnoDent® Avant™ achieved 75% treatment success versus 56% for the traditional, wing-based SomnoDent® Flex™ (P < 0.05). Overall, AHI reduction was 70% for SomnoDent® Avant™ (P < 0.05) vs. 63% for SomnoDent® Flex™ (P < 0.05).

CONCLUSIONS

This study shows that choice of MAD design can impact the treatment outcome and could become an important consideration in selecting the type of MAD for personalized treatment for OSA patients. While the results of the traditional wing-based MAD design were comparable to the therapeutic outcome with other titratable, custom-made MADs, the MAD with the passive mouth closing feature showed significantly greater reduction in total AHI potentially due to encouraged nasal breathing, reduced mouth breathing and lesser vertical opening thereby decreasing the probability of tongue base collapse.

Indications for Dental Specialists for Treating Obstructive Sleep Apnea with Mandibular Advancement Devices: A Narrative Review

Obstructive sleep apnea (OSA) syndrome is characterized by repeated airway collapse during sleep. It determines cardiovascular, pulmonary, and neurocognitive consequences and is associated with several daytime and nighttime symptoms that influence the patient's quality of life. The contribution of the dental specialist in the clinical management of OSA patients entails participating in the screening process as diagnostic sentinels and providing adequate treatment using mandibular advancement devices (MADs). Since the treatment of OSA requires a multidisciplinary approach, including different medical specialists, dentists should have a comprehensive understanding of medical and dental factors that influence the strategy and effectiveness of OSA treatment with MAD. Such expertise is crucial in determining the appropriate treatment indications and helps clinicians establish a consolidated position within the multidisciplinary OSA team. In this regard, this review summarizes the evidence of the clinical indications for MAD treatment and provides the dental specialist with helpful information about medical, functional, and other relevant factors that should be considered during diagnosis, treatment plan, and follow-up stages. Information retrieved was organized and discussed, generating specific domains/queries oriented to the clinical management of OSA patients from the clinical perspective of dental specialists.

Obstructive sleep apnea treatment improves temporomandibular disorder pain

PURPOSE

The existence of a bidirectional relationship between poor sleep and pain intensity has been studied, and good sleep quality has been found to be a key factor underlying pain control. The purpose of this prospective cohort study was to observe if OSA treatment provides a reduction in temporo-mandibular disorder (TMD) pain and headache attributed to TMD in patients with obstructive sleep apnea (OSA) after 18 months of OSA treatment.

METHODS

A prospective cohort study was conducted on consecutive patients suffering from OSA. Patients underwent polysomnography and TMD examination according to the DC/TMD protocol at baseline and after 18 months. Intensity of TMD pain and headache attributed to TMD were analyzed.

RESULTS

Of 40 patients (31 men, mean age 51.3 ± 10.3 years), 33 underwent OSA treatment. At the follow-up examination after 18 months, significant improvements in the intensity of pain-related TMD and headache attributed to TMD were observed (p < 0.05). Seven patients did not start treatment for OSA or discontinued treatment. These patients did not show any significant difference in intensity of TMD-pain or headache attributed to TMD after 18 months (p > 0.05).

CONCLUSIONS

Significant reductions in intensity of pain-related TMD and headache attributed to TMD were observed in patients with OSA after 18 months of OSA treatment onset, while no difference was observed in subjects not undergoing or discontinuing OSA treatment.

TRIAL REGISTRATION

The protocol was registered on ClinicalTrials.gov database with number NCT04948541.

The predictive value of mandibular advancement maneuvers during drug-induced sleep endoscopy for treatment success of oral appliance treatment in obstructive sleep apnea: a prospective study

STUDY OBJECTIVES

To prospectively validate drug-induced sleep endoscopy with mandibular advancement maneuvers as a prediction tool for treatment success of oral appliance treatment (OAT).

METHODS

Seventy-seven patients diagnosed with moderate obstructive sleep apnea were included and underwent drug-induced sleep endoscopy. The upper airway collapse was assessed using the VOTE classification. Additionally, three mandibular advancement maneuvers were performed to predict treatment success of OAT. If the maneuver was negative, the level and degree and configuration of the persistent collapse was described according to the VOTE classification. All patients were treated with OAT and completed a follow-up sleep study with OAT in situ without regard to their anticipated response to treatment.

RESULTS

Sixty-four patients completed 6-month follow up. A positive jaw thrust maneuver proved to be significantly associated with favorable OAT response, whereas the chin lift maneuver and the vertical chin lift maneuver were not. Additionally, a persistent lateral oropharyngeal collapse when performing any mandibular advancement maneuver was significantly associated with unfavorable OAT response.

CONCLUSIONS

The current findings suggest that a jaw thrust maneuver should be preferred over the chin lift maneuver for predicting OAT response. Patients with a positive jaw thrust maneuver should be counseled toward favorable OAT response, whereas those with persistent lateral oropharyngeal collapse should be advised about the likelihood of unfavorable OAT response. A negative jaw thrust maneuver did not prove to be a significant predictor for unfavorable response to OAT. Consequently, uncertainties arise regarding the justification of performing drug-induced sleep endoscopy solely for predicting the efficacy of OAT. However, the results of the current study could be influenced by heterogeneity in the assessment of respiratory parameters, variability in the performance of the mandibular advancement maneuvers, and the instability of bolus technique sedation.

CLINICAL TRIAL REGISTRATION

Registry: Netherlands Trial Register; Name: Drug-induced Sleep Endoscopy: a prediction tool for success rate of oral appliance treatment; Identifier: NL8425; URL: https://www.onderzoekmetmensen.nl/en/trial/20741.

CITATION

Veugen CCAFM, Kant E, Kelder JC, Schipper A, Stokroos RJ, Copper MP. The predictive value of mandibular advancement maneuvers during drug-induced sleep endoscopy for treatment success of oral appliance treatment in obstructive sleep apnea: a prospective study. J Clin Sleep Med. 2024;20(3): 353-361.

The prevalence of treatment-emergent central sleep apnea with mandibular advancement device therapy

STUDY OBJECTIVES

Treatment-emergent central sleep apnea (TECSA) describes the appearance or persistence of central sleep apnea while undergoing treatment for obstructive sleep apnea. TECSA is well studied in continuous positive airway pressure therapy with an estimated prevalence of 8%. Based on a few case reports, mandibular advancement devices (MAD) may also provoke TECSA. This study aims to gain insight into the prevalence of TECSA with MAD therapy.

METHODS

This retrospective study includes a total of 129 patients with moderate to severe obstructive sleep apnea who were treated with a custom-made titratable MAD. Baseline and follow-up sleep studies were compared to identify patients with TECSA. Since different diagnostic criteria to define TECSA are used in literature, prevalence was calculated according to three definitions (TECSA-1, -2, and -3). Demographics, MAD treatment variables, and findings of the diagnostic polysomnography were compared between TECSA and non-TECSA patients to identify possible predictors.

RESULTS

Depending on the definition used, TECSA was found in 3.1%-7.8% of patients undergoing MAD therapy. TECSA patients had a higher apnea index (9.2 vs 2.0 events/h, P = .042), central apnea-hypopnea index (4.1 vs 0.2 events/h, P = .045) and oxygen desaturation index (23.9 vs 16.3 events/h, P = .018) at baseline compared to non-TECSA patients. No differences were found in demographics and treatment variables.

CONCLUSIONS

These findings demonstrate that TECSA also occurs in patients starting MAD treatment. Patients with TECSA had a higher apnea index, central apnea-hypopnea index, and oxygen desaturation index at baseline compared to non-TECSA patients.

CITATION

Hellemans S, Van de Perck E, Braem MJ, Verbraecken J, Dieltjens M, Vanderveken OM. The prevalence of treatment-emergent central sleep apnea with mandibular advancement device therapy. J Clin Sleep Med. 2023;19(12):2035-2041.

Quantitative Measurement of Pharyngeal Dimensions During Drug-induced Sleep Endoscopy for Oral Appliance Outcome

OBJECTIVE

To quantitatively investigate the effect of mandibular advancement devices (MADs) on pharyngeal airway dimensions in a transverse plane as measured during drug-induced sleep endoscopy (DISE).

METHODS

Data from 56 patients, treated with MAD at 75% maximal protrusion and with baseline Apnea-Hypopnea Index ≥10 events/h, were analyzed. For each patient, three snapshots were selected from DISE video footage at baseline, with MAD presence, and during chin lift, resulting in 498 images (168/168/162, baseline/MAD/chin lift). Cross-sectional areas, anteroposterior (AP) and laterolateral (LL) dimensions on both retroglossal and retro-epiglottic levels were measured. To define the effect of MAD and chin lift on pharyngeal dimensions, linear mixed-effect models were built. Associations between MAD treatment response and pharyngeal expansion (MAD/chin lift) were determined.

RESULTS

Significant differences were found between retroglossal cross-sectional areas, AP, and LL dimensions at baseline and with MAD presence. At a retro-epiglottic level, only LL dimensions differed significantly with MAD presence compared to baseline, with significant relation of LL expansion ratio to treatment response (p = 0.0176). After adjusting the response definition for the sleeping position, greater retroglossal expansion ratios were seen in responders (1.32 ± 0.48) compared to non-responders (1.11 ± 0.32) (p = 0.0441). No significant association was found between response and pharyngeal expansion by chin lift.

CONCLUSION

Our observations highlight the additional value of quantitative pharyngeal airway measurements during DISE with MAD presence in evaluating MAD treatment outcome. These findings demonstrate an increase in retroglossal airway dimensions during DISE, with MAD presence, and more pronounced increase in retroglossal expansion ratios in MAD treatment responders compared to non-responders after sleeping position correction.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:3619-3627, 2023.

Three-dimensional evaluation of the effects of Bionator and Forsus appliances on oropharyngeal airway volume in patients with mandibular retrognathia

OBJECTIVE

To evaluate whether there is a difference between the effects of Bionator and Forsus appliances on airway volume.

METHODS

Forty patients with mandibular retrognathia were divided into two groups. The Bionator appliance was applied to Group 1, while the Forsus FRD EZ2 appliance was applied to Group 2. Three-dimensional images were captured before and after functional appliance use in both groups. Dolphin 3D software was used for airway measurements.

RESULTS

No statistically significant difference was found between the groups in terms of volumetric and area measurements. There was a statistically significant difference between the minimum axial T and O-N border T measurements of the groups.

CONCLUSION

The use of functional appliances may contribute to an increase in oropharyngeal airway dimensions, but there was no difference between the Bionator and Forsus groups in terms of volumetric measurements.

Computed Tomography versus Sleep Endoscopy (DISE) to Predict the Effectiveness of Mandibular Advancement Devices in Adult Patients with Obstructive Sleep Apnea: A Protocol for Systematic Review

Obstructive sleep apnea is a sleep disorder with a high prevalence in the world population. The mandibular advancement device is one of the options for treating obstructive sleep apnea. Neck computed tomography and drug-induced sleep endoscopy are complementary diagnostic tests that may help predict the effectiveness of mandibular advancement devices. This study aims to analyze the best method for predicting the effectiveness of mandibular advancement devices in the therapeutic approach to obstructive sleep apnea. PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science Core Collection databases will be comprehensively searched. We will include randomized clinical trials, non-randomized prospective or retrospective clinical studies, case controls, cohort studies, and case series. Two authors will independently conduct data extraction and assess the literature quality of the studies. The analysis of the included literature will be conducted by Revman 5.3 software. The outcomes that will be analyzed are craniofacial characteristics, cephalometric assessments, site and type of obstruction of the upper airway, mean values of the apnea-hypopnea index, and SaO2 verified in the initial and follow-up polysomnography. This study will provide reliable, evidence-based support for the clinical application of mandibular advancement devices for obstructive sleep apnea.

Salivary Biomarker Levels in Children with Sleep Problems Before and After Twin Block Therapy

BACKGROUND

Disturbances in sleep have a wide-ranging effect on a child's life profoundly impacting the standard of living. The aim of this study was to investigate levels of Salivary Tumor Necrosis Factor-Alpha (TNF-α) and Malondialdehyde (MDA) in a group of children with class II malocclusion and sleep problems before and after twin block appliance therapy.

MATERIALS AND METHODS

Eleven children aged 8-12 years with skeletal class II malocclusion and at least one sleep disorder participated in the study. All children were subjected to a recording of their sleep history and a clinical and radiographic examination. Pre-treatment levels of salivary TNF-α and MDA were recorded. A twin block appliance was custom made and delivered to every child. After a minimum follow-up period of 9 months, all children were recalled for a re-evaluation of salivary biomarker levels.

RESULTS

Levels of salivary biomarkers TNF-α and MDA significantly decreased in children following myofunctional therapy using a twin block appliance.

CONCLUSION

The measurement of TNF-α and MDA could be used as an alternative and noninvasive method to evaluate prognosis of twin block therapy for children with sleep-disordered breathing (SDB).

Three-dimensional evaluation of the association between tongue position and upper airway morphology in adults: A cross-sectional study

Objective

This study aimed to evaluate the association between low tongue position (LTP) and the volume and dimensions of the nasopharyngeal, retropalatal, retroglossal, and hypopharyngeal segments of the upper airway.

Methods

A total of 194 subjects, including 91 males and 103 females were divided into a resting tongue position (RTP) group and a LTP group according to their tongue position. Subjects in the LTP group were divided into four subgroups (Q1, Q2, Q3, and Q4) according to the intraoral space volume. The 3D slicer software was used to measure the volume and minimum and average cross-sectional areas of each group. Airway differences between the RTP and LTP groups were analyzed to explore the association between tongue position and the upper airway.

Results

No significant differences were found in the airway dimensions between the RTP and LTP groups. For both retropalatal and retroglossal segments, the volume and average cross-sectional area were significantly greater in the patients with extremely low tongue position. Regression analysis showed that the retroglossal airway dimensions were positively correlated with the intraoral space volume and negatively correlated with A point-nasion-B point and palatal plane to mandibular plane. Males generally had larger retroglossal and hypopharyngeal airways than females.

Conclusions

Tongue position did not significantly influence upper airway volume or dimensions, except in the extremely LTP subgroup.

The effect of surgical weight loss on upper airway fat in obstructive sleep apnoea

PURPOSE

Obesity is a reversible risk factor for obstructive sleep apnoea (OSA). Weight loss can potentially improve OSA by reducing fat around and within tissues surrounding the upper airway, but imaging studies are limited. Our aim was to study the effects of large amounts of weight loss on the upper airway and volume and fat content of multiple surrounding soft tissues.

METHODS

Participants undergoing bariatric surgery were recruited. Magnetic resonance imaging (MRI) was performed at baseline and six-months after surgery. Volumetric analysis of the airway space, tongue, pharyngeal lateral walls, and soft palate were performed as well as calculation of intra-tissue fat content from Dixon imaging sequences.

RESULTS

Among 18 participants (89% women), the group experienced 27.4 ± 4.7% reduction in body weight. Velopharyngeal airway volume increased (large effect; Cohen's d [95% CI], 0.8 [0.1, 1.4]) and tongue (large effect; Cohen's d [95% CI], - 1.4 [- 2.1, - 0.7]) and pharyngeal lateral wall (Cohen's d [95% CI], - 0.7 [- 1.2, - 0.1]) volumes decreased. Intra-tissue fat decreased following weight loss in the tongue, tongue base, lateral walls, and soft palate. There was a greater effect of weight loss on intra-tissue fat than parapharyngeal fat pad volume (medium effect; Cohen's d [95% CI], - 0.5 [- 1.2, 0.1], p = 0.083).

CONCLUSION

The study showed an increase in velopharyngeal volume, reduction in tongue volume, and reduced intra-tissue fat in multiple upper airway soft tissues following weight loss in OSA. Further studies are needed to assess the effect of these anatomical changes on upper airway function and its relationship to OSA improvement.

Salivary biomarker C-reactive protein levels in children with sleep problems and Class II malocclusion before and after twin-block therapy

Context

Disturbances in sleep affects the overall quality of a child's life, with several short- and long-lasting consequences. Hence, early diagnosis and monitoring is crucial in the management of sleep disorders in children.

Aims

The aim of this study was to evaluate salivary C-reactive protein (CRP) levels in a group of children with Class II malocclusion and sleep problems before and after twin-block appliance therapy.

Settings and Design

The study was a prospective clinical study with a 9-month follow-up period.

Subjects and Methods

Eleven children aged 8-12 years with skeletal Class II malocclusion and at least one sleep disorder were enrolled in the study. All children were subjected to a recording of their sleep history and a clinical as well as radiographic examination. Pretreatment levels of salivary CRP were recorded. A twin-block appliance was custom made and delivered to every child. At the end of 9-month follow-up, all children were recalled for a re-evaluation of salivary biomarker levels.

Statistical Analysis

Pretreatment and posttreatment changes in biomarker levels were assessed statistically using the students paired t-test.

Results

Levels of salivary biomarker CRP were significantly decreased in children following myofunctional therapy using a twin-block appliance (P < 0.001). There was a considerable improvement in the clinical symptoms such as a decrease in snoring and noisy breathing in most children post-twin-block therapy.

Conclusion

The measurement of salivary biomarker CRP could be used as an alternative and noninvasive method to evaluate prognosis of oral myofunctional therapy for children with sleep disordered breathing.

The role of oral appliance therapy in obstructive sleep apnoea

There is now widespread recognition within the world of sleep medicine of the increasing importance of dental sleep medicine and, in particular, the role of oral appliance therapy (OAT) in the management of adults with obstructive sleep apnoea (OSA). For the purpose of this review, the term OAT refers to a custom-made intra-oral appliance, which acts to posture the mandible in a forward and downward direction, away from its natural resting position. Whilst nasally applied continuous positive airway pressure remains the "gold standard" in nonsurgical OSA management, OAT remains the recognised alternative treatment.This review of OAT aims to provide an evidence-based update on our current understanding of their mode of action, exploring the potential anatomical and physiological impact of their use in preventing collapse of the upper airway; the current clinical practice guidelines, including the recently published National Institute of Clinical Excellence 2021 guidance, in conjunction with the American Academy of Sleep Medicine and American Academy of Dental Sleep Medicine; optimal design features, comparing the role of custom-made versus noncustom OAT devices and the importance of titration in achieving a dose-dependent effect; patient predictors, preference and adherence to OAT; its impact on a range of both patient- and clinician-centred health outcomes, with a comparison with CPAP; the limitations and side-effects of providing OAT; and, finally, a look at future considerations to help optimise the delivery and outcomes of OAT.

The Effect of Bite Raise on AHI Values in Adult Patients Affected by OSA: A Systematic Review with Meta-Regression

Obstructive sleep apnea (OSA) is a highly prevalent sleep breathing disorder characterized by the collapse of the pharyngeal walls that entails recurrent episodes of cessation of breathing or decrease in airflow while sleeping. This results in sleep fragmentation, decreased oxygen saturation and an increase in the partial pressure of carbon dioxide, causing excessive daytime sleepiness, hypertension and increased prevalence of cardiovascular morbidity and mortality. Mandibular advancement devices (MAD) represent a valid alternative therapy to Continuous Positive Airway Pressure, thrusting the mandible forward, increasing the lateral diameter of the pharynx and reducing the collapsibility of the airway. Several investigations have focused on the detection of the best mandibular advancement amount in terms of effectiveness and tolerance, but few and contrasting data are available on the role of occlusal bite raise in reducing the apnea/hypopnea index (AHI). The aim of this systematic review with meta-regression analysis was to investigate the effect of the bite raise of MAD on AHI values in adult patients affected by OSA. An electronic search was performed in MEDLINE, the Cochrane Database, Scopus, Web of Science and LILACS. Randomized controlled trials (RCT) investigating the effectiveness of MAD in OSA patients were included. The quality of evidence was evaluated with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) and the risk of bias with the Cochrane risk-of-bias tool for randomized trials (RoB2). Six RCT were included. The success rate of each study was computed: (mean baseline AHI - mean post treatment AHI)/mean baseline AHI. The GRADE scores indicated that the quality of evidence was very low. The meta-regression analysis showed that there was no correlation between the occlusal bite raise and the AHI improvement.

Comparisons of the effects of two types of titratable mandibular advancement devices on respiratory parameters and upper airway dimensions in patients with obstructive sleep apnea: a randomized controlled trial

OBJECTIVES

To compare the effects of two types of titratable mandibular advancement devices (MADs), namely MAD-H (allowing limited vertical opening) and MAD-S (allowing free vertical opening), on respiratory parameters and upper airway dimensions in patients with mild to moderate obstructive sleep apnea (OSA).

MATERIALS AND METHODS

Patients with mild to moderate OSA (5 ≤ apnea-hypopnea index (AHI) < 30 /h) were randomly assigned to two parallel MAD groups. All MADs were subjectively titrated according to a standardized protocol during a 3-month follow-up. Every patient underwent two polysomnographic recordings, and two cone beam computed tomography scans in supine position: one at baseline and another one after 3 months with the MAD in situ. The primary outcome variables were the AHI in supine position (AHI-supine) and the minimal cross-sectional area of the upper airway in supine position (CSAmin-supine).

RESULTS

A total of 49 patients were recruited, and 31 patients (21 men and 10 women) with a mean (± SD) age of 48.5 (± 13.9) years and a mean AHI of 16.6 (± 6.7) /h completed the study. In the per-protocol analysis, there was no significant difference between MAD-H (n = 16) and MAD-S (n = 15) in their effects on AHI-supine (P = 0.14) and CSAmin-supine (P = 0.59). Similar results were found in the intention-to-treat analysis (P = 0.47 and 0.57, respectively).

CONCLUSIONS

Within the limitations of this study, we conclude that there is no significant difference in the effects of an MAD allowing limited vertical opening and an MAD allowing free vertical opening on respiratory parameters and upper airway dimensions in patients with mild to moderate OSA.

CLINICAL RELEVANCE

MADs allowing limited vertical opening and allowing free vertical opening have similar effects on respiratory parameters and upper airway dimensions in patients with mild to moderate OSA.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02724865. https://clinicaltrials.gov/ct2/show/NCT02724865.

Pharyngeal Inflammation on Positron Emission Tomography/Magnetic Resonance Imaging Before and After Obstructive Sleep Apnea Treatment

Rationale: There is upper airway inflammation in patients with obstructive sleep apnea (OSA), which reduces with continuous positive airway pressure (CPAP) therapy. Objectives: Validate the use of positron emission tomography (PET)/magnetic resonance imaging (MRI) to quantify metabolic activity within the pharyngeal mucosa of patients with OSA against nasal lavage proteomics and assess the impact of CPAP therapy. Methods: Adults with OSA underwent [18F]-Fluoro-2-deoxy-D-glucose PET/MRI of the neck before and 3 months after initiating CPAP. Nasal lavage samples were collected. Inflammatory protein expression from samples was analyzed using the Olink platform. Upper airway imaging segmentation was performed. Target-to-background ratio (TBRmax) was calculated from target pharyngeal maximum standard uptake values (SUV) and personalized background mean SUV. Most-diseased segment TBRmax was identified per participant at locations with the highest PET avidity. Correlation analysis was performed between baseline TBRmax and nasal lavage proteomics. TBRmax was compared before and after CPAP using linear mixed-effect models. Results: Among 38 participants, the baseline mean age was 46.3 years (standard deviation [SD], 12.5), 21% were female, the mean body mass index was 30.9 kg/m2 (SD, 4.6), and the mean respiratory disturbance index measured by peripheral arterial tonometry was 31 events/h (SD, 16.4). There was a significant positive correlation between pharyngeal mucosa most-diseased segment TBRmax and nasal lavage proteomic inflammation (r = 0.41 [P < 0.001, false discovery rate = 0.002]). Primary analysis revealed a reduction in the most-diseased segment TBRmax after a median of 2.91 months of CPAP therapy (-0.86 [standard error (SE) ± 0.30; P = 0.007]). Stratified analysis by smoking status revealed a significantly decreased most-diseased segment TBRmax after CPAP therapy among never-smokers but not among ever-smokers (-1.01 [SE ± 0.39; P = 0.015] vs. -0.64 [SE ± 0.49; P = 0.201]). Conclusions: CPAP therapy reduces metabolic activity measured by PET/MRI within the upper airway of adults with OSA. Furthermore, PET/MRI measures of upper airway metabolic activity correlate with a noninvasive marker of inflammation (i.e., nasal lavage inflammatory protein expression).

Antero-Posterior Mandibular Excursion in Obstructive Sleep Apnea Patients Treated with Mandibular Advancement Device: A Retrospective Cohort Study

Since obstructive sleep apnea (OSA) management with a mandibular advancement device (MAD) is likely to be life-long, potential changes in mandibular movements during therapy should be investigated. The purpose of this study was to use a method that has already been shown to be reliable in order to determine whether the range of antero-posterior mandibular excursion, the procedure upon which MAD titration is based, varies between baseline (T0) and at least 1 year of treatment (T1). The distance between maximal voluntary protrusion and maximal voluntary retrusion determined using the millimetric scale of the George Gauge was retrospectively collected from the medical records of 59 OSA patients treated with the MAD and compared between T0 and T1. A regression analysis was performed to evaluate the influence of treatment time, MAD therapeutic advancement and the patient's initial characteristics in excursion range variation. A statistically significant increase of 0.80 ± 1.52 mm (mean ± standard deviation, p < 0.001) was found for antero-posterior mandibular excursion. The longer the treatment time (p = 0.044) and the smaller the patient's mandibular excursion at T0 (p = 0.002), the greater the increase was. These findings could be explained by a muscle-tendon unit adaptation to the forward mandibular repositioning induced by the MAD. During MAD therapy, patients can develop a wider range of antero-posterior mandibular excursion, especially those with a smaller initial excursion capacity.

Obstructive sleep apnea: a review for the orthodontist

INTRODUCTION

Obstructive sleep apnea (OSA) affects an important part of the population and is characterized by recurrent total or partial obstruction of the upper airway (UA) during sleep, negatively affecting the quality of life of patients in the short and long terms, and constituting an important public health problem for the society. The field of expertise of orthodontists is closely related to the UA, placing them in a strategic position to diagnose air passage failures and intervene when necessary. Orthodontists, as health professionals, must know how to recognize respiratory problems and manage them appropriately, when indicated.

OBJECTIVE

Thus, this paper aims to review and critically evaluate the related literature, to provide orthodontists with updated knowledge on the diagnosis and therapy related to OSA. Science and technology are constantly evolving; thus, the literature was also reviewed considering new technologies available in consumer-targeted applications and devices for the diagnosis, monitoring, and treatment of sleep-disordered breathing.

Mandibular Advancement Device (MAD) for Obstructive Sleep Apnea in an Edentulous Patient

Mandibular advancement devices have been efficiently used for the treatment of mild to moderate obstructive sleep apnea (OSA) by forward positioning of the tongue-mandible complex with a resultant increase in oropharyngeal volume. However, the literature on the treatment of edentulous patients is limited. This clinical report describes a clinical and laboratory method for the fabrication of a mandibular advancement device in a 75-year-old completely edentulous patient with mild OSA.

Patients with Obstructive Sleep Apnea and Cardiovascular Diseases: What, When, and Why Is Mandibular Advancement Device Treatment Required? A Short Review

Obstructive sleep apnea is a potentially dangerous condition with significant risks of comorbidities if left untreated. It represents a cardiovascular risk factor in the general population, and a higher prevalence is observed in patients already suffering from cardiovascular diseases. The gold standard treatment, continuous positive airway pressure, is not always accepted or tolerated. The mandibular advancement device represents an alternative treatment that we propose to implement in our study. The objective here is to first present a brief review of the topic. Due to poor evidence in the field, we propose a pilot study to evaluate the effect of a mandibular advancement device in patients with cardiovascular disease who are not treated for their sleep pathology in order to improve their therapeutic management.

Maxillomandibular Advancement and Upper Airway Stimulation for Treatment of Obstructive Sleep Apnea: A Systematic Review

This systematic review aimed to comparatively evaluate the efficacy and safety of maxillomandibular advancement (MMA) and upper airway stimulation (UAS) in obstructive sleep apnea (OSA) treatment. A MEDLINE and Embase database search of articles on MMA and/or UAS for OSA was conducted. Twenty-one MMA studies and nine UAS studies were included. All the MMA studies demonstrated a reduction in apnea hypopnea index (AHI) postoperatively, and success rates ranged from 41.1% to 100%. Ten MMA studies reported pre- and postoperative Epworth sleepiness scale (ESS), and all but one study demonstrated a reduction in ESS. In the UAS studies, all but one demonstrated a reduction in AHI, and success rates ranged from 26.7% to 77.8%. In the eight UAS studies reporting pre- and postoperative ESS, an ESS reduction was demonstrated. No studies reported any deaths related to MMA or UAS. The most common postoperative complications after MMA and UAS were facial paresthesia in the mandibular area and discomfort due to electrical stimulation, respectively. This systematic review suggests that both MMA and UAS are effective and generally safe therapies for OSA. However, due to the limitations of the included studies, there is no evidence yet to directly compare these two procedures in OSA treatment.

Effects of oral appliances on serum cytokines in adults with obstructive sleep apnea: a systematic review

PURPOSE

This review aimed to evaluate the effects of oral appliance (OA) therapy on serum inflammatory cytokines in adults diagnosed with obstructive sleep apnea (OSA).

METHODS

Seven electronic databases and partial gray literature were searched without restrictions through March 2021. Articles evaluating the levels of serum inflammatory cytokines in patients with OSA after OA treatment were included. The risk of bias (RoB) was assessed using the before-and-after tool or RoB 2.0. The level of certainty was assessed using the GRADE tool.

RESULTS

Five studies met the eligibility criteria. One was a randomized clinical trial (RCT), while four were non-randomized clinical trials (NRCTs). Among the studies, C-reactive protein (CRP), IL-6, IL-10, IL-1β, and tumor necrosis factor α (TNF-α) were investigated. The RCT reported no significant differences in marker levels after 2 months of OA therapy, while the NRCTs showed improvement on CRP, TNF-α, and IL-1β levels after longer follow-up periods. The RoB was evaluated as showing some concern in the RCT. Three NRCTs presented good RoB, and one showed a fair RoB. The level of certainty was graded as moderate quality for inflammatory marker levels assessed in the RCT The levels of certainty evaluated in NRCTs were classified as very low.

CONCLUSIONS

Although limited, existing scientific evidence showed that OA therapy may improve serum cytokine levels in adults with OSA. However, short treatment periods are not effective in reducing markers of systemic inflammation which may require extended time and a decrease of in apneic events to improve.

Effectiveness of Titratable Oral Appliance in Management of Moderate to Severe Obstructive Sleep Apnea-A Prospective Clinical Study with Acoustic Pharyngometry

To assess effectiveness of titratable Oral Appliance (OA) in management of moderate to severe cases of Obstructive Sleep Apnea (OSA). Thirty Polysomnography (PSG) diagnosed cases of moderate to severe OSA were subjected to a thorough cranio-facial-dental evaluation, a detailed sleep history and three dimensional assessment of upper airway geometry utilising Acoustic Pharyngometry (AP) (Eccovision, sleep group solutions). A titratable OA was delivered to all patients for mandibular advancement. Apnea Hypopnea Index (AHI), Oxygen Saturation (SPO2), Epworth's Sleepiness Scale (ESS), Mean area and volume of upper airway were recorded at Baseline (T0) and after 08 weeks of appliance delivery (T1). The mean AHI & ESS scores were significantly lower and SPO2 was significantly higher at T1 compared to T0 (P-value < 0.05 for all). The mean area and volume of upper airway at T1 were significantly higher compared to values at T0 (P-value < 0.05 for both). The mean area showed 19.51% increase at T1 whereas mean volume increased by 18.55%. OA therapy is highly efficacious in cases with moderate to severe OSA, especially, in those with retrognathic mandible. This modality should be considered as an effective alternate to Continuous Positive Airway Pressure (CPAP) therapy in non-compliant patients rather than no treatment. AP is an effective modality to predict airway changes after advancement with OA, to ascertain follow up changes and is highly recommended in routine clinical practice. Large scale, multicenter studies are recommended to elaborate the findings of the present study and to add better quality evidence in this regard.

Obstructive sleep apnea: personalizing CPAP alternative therapies to individual physiology

Introduction The recent continuous positive airway pressure (CPAP) crisis has highlighted the need for alternative obstructive sleep apnea (OSA) therapies. This article serves to review OSA pathophysiology and how sleep apnea mechanisms may be utilized to individualize alternative treatment options.Areas covered: The research highlighted below focuses on 1) mechanisms of OSA pathogenesis and 2) CPAP alternative therapies based on mechanism of disease. We reviewed PubMed from inception to July 2022 for relevant articles pertaining to OSA pathogenesis, sleep apnea surgery, as well as sleep apnea alternative therapies.Expert opinion: Although the field of individualized OSA treatment is still in its infancy, much has been learned about OSA traits and how they may be targeted based on a patient's physiology and preferences. While CPAP remains the gold-standard for OSA management, several novel alternatives are emerging. CPAP is a universal treatment approach for all severities of OSA. We believe that a personalized approach to OSA treatment beyond CPAP lies ahead. Additional research is needed with respect to implementation and combination of therapies longitudinally, but we are enthusiastic about the future of OSA treatment based on the data presented here.

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.

The relationship between mandibular advancement, tongue movement, and treatment outcome in obstructive sleep apnea

Study Objectives

To characterize how mandibular advancement enlarges the upper airway via posterior tongue advancement in people with obstructive sleep apnea (OSA) and whether this is associated with mandibular advancement splint (MAS) treatment outcome.

Methods

One-hundred and one untreated people with OSA underwent a 3T magnetic resonance (MRI) scan. Dynamic mid-sagittal posterior tongue and mandible movements during passive jaw advancement were measured with tagged MRI. Upper airway cross-sectional areas were measured with the mandible in a neutral position and advanced to 70% of maximum advancement. Treatment outcome was determined after a minimum of 9 weeks of therapy.

Results

Seventy-one participants completed the study: 33 were responders (AHI&lt;5 or AHI≤10 events/hr with &gt;50% AHI reduction), 11 were partial responders (&gt;50% AHI reduction but AHI&gt;10 events/hr), and 27 nonresponders (AHI reduction&lt;50% and AHI≥10 events/hr). Responders had the greatest naso- and oropharyngeal tongue anterior movement (0.40 ± 0.08 and 0.47 ± 0.13 mm, respectively) and oropharyngeal cross-sectional area enlargement (6.41 ± 2.12%) per millimeter of mandibular advancement. A multivariate model that included tongue movement and percentage of airway enlargement per millimeter of mandibular advancement along with baseline AHI correctly classified 69.2% (5-fold cross-validated 62.5%, n = 39) of participants in response categories when the jaw was advanced in the range that would usually be regarded as sufficient for clinical efficacy (&gt; 4 mm). In comparison, a model using only baseline AHI correctly classified 50.0% of patients (5-fold cross-validated 52.5%, n = 40).

Conclusions

Tongue advancement and upper airway enlargement with mandibular advancement in conjunction with baseline AHI improve treatment response categorization to a satisfactory level (69.2%, 5-fold cross-validated 62.5%).

Pharyngeal Airspace Alterations after Using the Mandibular Advancement Device in the Treatment of Obstructive Sleep Apnea Syndrome

Background: Mandibular Advancement Devices (MADs), inserted in non-surgical treatments for obstructive sleep apnea and hypopnea syndrome (OSAHS), are used intra-orally during the sleep period, with the aim of promoting mandibular protrusion. The aim of the study is to analyze the changes in the upper airway after the use of an MAD in the treatment of OSAHS. Methods: 60 patients diagnosed with OSAHS, as established by the Sleep Medicine Service, underwent treatment with the Silensor SL device at the Stomatology Service of the University Hospital Center of Coimbra, from January 2018 to January 2019. All patients completed two polysomnographies and two lateral teleradiographies: one before starting treatment (T0) and one after 1 year of treatment (T1). In the lateral teleradiography performed after one year of treatment, the patient had the MAD placed intra-orally. The linear measurements of the airspace proposed by the Arnett/Gunson FAB Surgery cephalometric analysis were measured at four craniometric points: A, MCI, B, Pog. Results: The results demonstrate an anteroposterior airway enlargement in two of the four points studied with the MAD placed intra-orally (B and Pog point). The greatest average increase is observed at point Pog (3 mm), followed by B (1 mm), and finally, point A (0.6 mm). Conclusions: This study proved that there is an improvement in anteroposterior measurements at various points in the upper airways after treatment with MAD.

Post-Operative Patients’ Satisfaction and Quality of Life Assessment in Adult Patients with Obstructive Sleep Apnea Syndrome (OSAS)

Background: The treatment for severe OSAS includes maxillomandibular advancement surgical option in selected cases. The aim of this study was to evaluate the post-operative impact of bimaxillary surgery on satisfaction and consequently the quality of life of these patients. Methods: This study included 18 patients with severe OSAS who received maxillomandibular advancement surgery. Patients were divided into Group A (operated by CAD/CAM) and Group B (conventional surgery). The impact of bimaxillary surgery on satisfaction and quality of life of these patients was evaluated by utilizing post-operative life quality and Rustemeyer’s patient-satisfaction-based survey. Results: A total of 18 adult OSAS patients (Group A: 11 patients, Group B: 7 patients) with a mean age of 44.39 years (SD ± 9.43) were included. Mean follow-up period was 32.64 months (SD ± 21.91). No intra-operative complications were seen in any patients. Post-operative complication was seen in one patient and the mandible did not integrate. According to the results, overall post-operative satisfaction score was 79.72% (SD ± 9.96). There was no significant difference among those in Group A and Group B. Conclusion: Maxillomandibular advancement surgery seems to be beneficial in terms of patients’ satisfaction in severe adult OSAS patients and can be considered as a valuable option in selected cases.

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.

Effects of Wearing a 50% Lower Jaw Advancement Splint on Biophysical and Perceptual Responses at Low to Severe Running Intensities

Acute ergogenic effects of wearing occlusal splints have been reported for aerobic and anaerobic exercises, but the literature centered on performance improvement by using jaw repositioning splints is scarce. We aimed to analyze the effect of wearing a 50% lower jaw advancement splint on biophysical and perceptual responses at low to severe running intensities. Sixteen middle- and long-distance runners performed twice a 7 × 800 m intermittent running protocol (with 1 km·h⁻¹ increments and 30 s rest periods) in an outdoor track field using two lower intraoral splints (a placebo and a lower jaw advancer). These devices were custom manufactured for each participant and a randomized and repeated measure design was used to compare conditions. No differences between placebo and lower jaw advancer were found (e.g., 52.1 ± 9.9 vs. 53.9 ± 10.7 mL·kg⁻¹·min⁻¹ of oxygen uptake, 3.30 ± 0.44 vs. 3.29 ± 0.43 m of stride length and 16 ± 3 vs. 16 ± 2 Borg scores), but small effects were sometimes observed (e.g., 109.2 ± 22.5 vs. 112.7 ± 25.2 L·min⁻¹ of ventilation, ES = −0.42). Therefore, this jaw advancement splint had no substantial ergogenic effect on biophysical and perceptual responses when running at different intensities.

Case Study: A Jaw-Protruding Dental Splint Improves Running Physiology and Kinematics

Wearing an intraoral jaw-protruding splint could enhance respiratory function in clinical settings and eventually exercise performance.

PURPOSE

The authors studied the acute effect of wearing a lower-jaw-forwarding splint at different protruding percentages (30% and 50%) across a wide range of running exercise intensities.

METHODS

A case study was undertaken with a highly trained and experienced 27-year-old female triathlete. She performed the same incremental intermittent treadmill running protocol on 3 occasions wearing 3 different intraoral devices (30% and 50% maximum range and a control device) to assess running physiological and kinematic variables.

RESULTS

Both the 30% and 50% protruding splints decreased oxygen uptake and carbon dioxide production (by 4%-12% and 1%-10%, respectively) and increased ventilation and respiratory frequency (by 7%-12% and 5%-16%, respectively) along the studied running intensities. Exercise energy expenditure (approximately 1%-14%) and cost (7.8, 7.4, and 8.0 J·kg-1·m-1 for 30%, 50%, and placebo devices, respectively) were also decreased when using the jaw-protruding splints. The triathlete's lower limbs' running pattern changed by wearing the forwarding splints, decreasing the contact time and stride length by approximately 4% and increasing the stride rate by approximately 4%.

CONCLUSIONS

Wearing a jaw-protruding splint can have a positive biophysical effect on running-performance-related parameters.

The role of orthodontics in management of obstructive sleep apnea

Dental sleep medicine is the field of dental practice that deals with the management of sleep-related breathing disorders, which includes obstructive sleep apnea (OSA) in adults and children. Depending on the developmental age of the patient and the cause of the apnea dental treatment options may vary. For adult patients, treatment modalities may include oral appliance therapy (OAT), orthognathic surgery and surgical or miniscrew supported palatal expansion. While for children, treatment may include non-surgical maxillary expansion and orthodontic functional appliances. Many physicians and dentists are unaware of the role dentistry, particularly orthodontics, may play in the interdisciplinary management of these disorders. This review article is an attempt to compile evidence-based relevant information on the role of orthodontists/sleep dentists in the screening, diagnosis, and management of sleep apnea. Oral sleep appliance mechanisms of action, selective efficacy, and the medical physiological outcomes are discussed. The purpose of this review is to provide a comprehensive understanding of how orthodontists and sleep physicians can work in tandem to maximize the benefits and minimize the side effects while treating patients with OSA.

A pilot study on comparison of subjective titration versus remotely controlled mandibular positioning during polysomnography and drug-induced sleep endoscopy, to determine the effective protrusive position for mandibular advancement device therapy

Study objectives

The aim of this pilot study was to evaluate the clinical effectiveness of subjective titration versus objectively guided titration during polysomnography (PSG) and drug-induced sleep endoscopy (DISE) in mandibular advancement device (MAD) therapy for patients with obstructive sleep apnea (OSA).

Methods

In this pilot cross-over study, patients underwent three titration procedures in randomized order: (1) subjective titration, (2) PSG-guided titration using a remotely controlled mandibular positioner (RCMP) and (3) DISE-assisted titration using RCMP. After each titration procedure, patients used the MAD for 1 month at the targeted protrusion obtained according to the preceding titration procedure. For each procedure, a follow-up PSG was performed after 1 month of MAD use in order to evaluate the efficacy of the MAD.

Results

Ten patients were included in the study. Overall, no significant differences in targeted optimal protrusion compared to maximal comfortable protrusion among the three titration methods were observed. There was no significant difference in reduction in AHI. In this study, PSG titration correctly classified 50% of patients as ‘responder’. A higher predictive accuracy was found for DISE titration with a sensitivity of 83.3% and a specificity of 100%.

Conclusions

This pilot randomized cross-over trial showed no differences in optimal mandibular positioning and corresponding efficacy of MAD between subjective titration, DISE titration or PSG titration.

Volumetric magnetic resonance imaging analysis of multilevel upper airway surgery effects on pharyngeal structure

STUDY OBJECTIVES

The Sleep Apnea Multilevel Surgery (SAMS) trial found that modified uvulopalatopharyngoplasty with tonsillectomy (if tonsils present) combined with radiofrequency tongue ablation reduced obstructive sleep apnea (OSA) severity and daytime sleepiness in moderate-severe OSA. This study aimed to investigate mechanisms of effect on apnea-hypopnea index (AHI) reduction by assessing changes in upper airway volumes (airway space, soft palate, tongue, and intra-tongue fat).

METHODS

This is a case series analysis of 43 participants of 51 randomized to the surgical arm of the SAMS trial who underwent repeat magnetic resonance imaging (MRI). Upper airway volume, length, and cross-sectional area, soft palate and tongue volumes, and tongue fat were measured. Relationships between changes in anatomical structures and AHI were assessed.

RESULTS

The participant sample was predominantly male (79%); mean ± SD age 42.7 ± 13.3 years, body mass index 30.8 ± 4.1 kg/m2, and AHI 47.0 ± 22.3 events/hour. There were no, or minor, overall volumetric changes in the airway, soft palate, total tongue, or tongue fat volume. Post-surgery there was an increase in the minimum cross-sectional area by 0.1 cm2 (95% confidence interval 0.04-0.2 cm2) in the pharyngeal airway, but not statistically significant on corrected analysis. There was no association between anatomical changes and AHI improvement.

CONCLUSIONS

This contemporary multilevel upper airway surgery has been shown to be an effective OSA treatment. The current anatomical investigation suggests there are not significant post-operative volumetric changes associated with OSA improvement 6-month post-surgery. This suggests that effect on OSA improvement is achieved without notable deformation of airway volume. Reduced need for neuromuscular compensation during wake following anatomical improvement via surgery could explain the lack of measurable volume change. Further research to understand the mechanisms of action of multilevel surgery is required.

CLINICAL TRIAL

This manuscript presents a planned image analysis of participants randomized to the surgical arm or the clinical trial multilevel airway surgery in patients with moderate-severe obstructive sleep apnea (OSA) who have failed medical management to assess change in OSA events and daytime sleepiness. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=266019&isReview=true%20Australian%20New%20Zealand%20Clinical%20Trials%20Registry%20ACTRN12514000338662, prospectively registered on March 31, 2014.

Dropout and adherence of obstructive sleep apnoea patients to mandibular advancement device therapy: A systematic review of randomised controlled trials with meta-analysis and meta-regression

BACKGROUND

Mandibular advancement devices (MADs) are used as an alternative to continuous positive airways pressure to treat obstructive sleep apnoea (OSA) patients, but to date, specific data on the adherence to MAD therapy are lacking.

OBJECTIVES

The aim of the present systematic review was to investigate the dropout rate and adherence of OSA patients to different custom-made (CM) and non-custom-made (NCM) MAD therapies.

SEARCH METHODS

An electronic search was performed in MEDLINE, Cochrane Database of Systematic Reviews, Scopus, LILACS and Web of Science.

SELECTION CRITERIA

Randomised controlled trials (RCTs) assessing the compliance to customised and not customised MADs in the treatment of adult OSA patients were included.

DATA COLLECTION AND ANALYSIS

The quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) and the risk of bias by the Cochrane Collaboration's tool for assessing risk of bias in RCT. The dropout rate of each study was computed and the adherence to MAD therapy in terms of hours per night and nights per week was extracted from each study.

RESULTS

Thirty-two RCTs were included. The risk of bias resulted low in most of the studies. The GRADE scores indicated that the quality of evidence was from very low to moderate. The meta-analyses showed that the mean dropout rate did not significantly differ between CM and NCM MADs: The overall mean dropout rate was 0.171 [0.128-0.213] with a mean follow-up of 4.1 months. The hours per night adherence was significantly higher for CM MADs (6.418 [6.033-6.803]) compared to NCM MADs (5.107 [4.324-5.890]. The meta-regression showed that the dropout rate increases significantly during time (p < .05).

CONCLUSIONS

There is a very low to moderate quality of evidence that the dropout rate of MAD therapy is similar among CM and NCM MADs, that the dropout rate increases significantly during time and that CM MADs have higher hours per night adherence compared with NCM MAD.

REGISTRATION

The study protocol was registered on PROSPERO (n. CRD42020199866).