Updates in oral appliance therapy for snoring and obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is increasingly being recognized by the public due to its life-threatening and low curability rate nature. Oral appliances (OAs) were introduced as a treatment option for both non-apneic snoring and OSA to maintain the patency of the upper airway during sleep by repositioning the mandible, tongue, and soft palate.

Results

Over the past decade, OAs are enthusiastically studied and concluded as a simple, silent, bed partner-friendly, less invasive, tolerable, and efficacious choice for mild-to-moderate OSA. In the meantime, some challenges remain uncertain such as titration management, 3D image diagnostic tools reliability, and long-term adherence for adult patients. Improvement of temporomandibular joint (TMJ) monitoring and management is recommended, although there is no scientific evidence suggesting consistent undesirable long-term effects of OA on the TMJ. Now that pediatric OSA is being diagnosed more frequently, OA therapy is becoming a promising option for children as well.

Conclusion

Consistent follow-up and management are needed to increase clinical success rates in OA therapy for OSA. Further educational preparation and support is required for dental and medical professionals to recognize OSA and ensure the best possible patient care.     

Dental appliance treatment for obstructive sleep apnea

Oral appliances for the treatment of obstructive sleep apnea (OSA) are worn during sleep to maintain the patency of the upper airway by increasing its dimensions and reducing its collapsibility. Oral appliances are a simpler alternative to continuous positive airway pressure (CPAP). Over the last decade, there has been a significant expansion of the evidence base to support the use of oral appliances, with robust studies demonstrating their efficacy. This work has been underpinned by the recognition of the importance of upper airway anatomy in the pathophysiology of OSA. The updated practice parameters of the American Academy of Sleep Medicine now recommend their use for mild-to-moderate OSA, or for patients with severe OSA who are unable to tolerate CPAP or refuse treatment with CPAP. Oral appliances have been shown to have a beneficial impact on a number of important clinical end points, including the polysomnographic indexes of OSA, subjective and objective measures of sleepiness, BP, aspects of neuropsychological functioning, and quality of life. Elucidation of the mechanism of action of oral appliances has provided insight into the factors that predict treatment response and may improve the selection of patients for this treatment modality. Longitudinal studies to characterize the long-term adverse effects of oral appliance use are now beginning to emerge. Although less efficacious than CPAP for improving the polysomnographic indexes of OSA, oral appliances are generally preferred by patients. This has the potential to translate to better patient adherence and may provide an equivalent health outcome.     

Effect of oral appliance therapy on upper airway collapsibility in obstructive sleep apnea

Oral appliance therapy is emerging as an alternative to continuous positive airway pressure for the treatment of obstructive sleep apnea (OSA). However, its precise mechanisms of action are yet to be defined. We examined the effect of a mandibular advancement splint (MAS) on upper airway collapsibility during sleep in OSA. Ten patients with proven OSA had a custom-made MAS incrementally adjusted during an acclimatization period until the maximum comfortable limit of mandibular advancement was reached. Polysomnography with the splint was then performed. After a 1-week washout period, upper airway closing pressures during sleep (with and without MAS) were determined. Significant improvements with MAS therapy were seen in the apnea/hypopnea index (25.0 +/- 3.1 vs. 13.2 +/- 4.5/hour, p < 0.03) and upper airway closing pressure in Stage 2 sleep (-1.6 +/- 0.4 vs. -3.9 +/- 0.6 cm H2O, p < 0.01) and in slow wave sleep (-2.5 +/- 0.7 vs. -4.7 +/- 0.6 cm H2O, p < 0.02) compared with no therapy. These preliminary data indicate that MAS therapy is associated with improved upper airway collapsibility during sleep. The mediators of this effect remain to be determined.     

The effect of oral appliance therapy on blood pressure in patients with obstructive sleep apnea

The objective of the study was to investigate the effects of oral appliance (OA) therapy on ambulatory blood pressure in patients with obstructive sleep apnea (OSA). Eleven OSA patients who received OA therapy were prospectively investigated. Ambulatory blood pressure was measured for 20 h from 4:00 p.m. to 12:00 noon the next day using an ambulatory blood pressure monitor. The Respiratory Disturbance Index (RDI) was measured in the pretreatment and posttitration periods. The OA was titrated to reach a therapeutic jaw position over 2 to 8 months, and posttitration measurements were repeated. At posttitration, the RDI was significantly decreased from a mean (SD) of 24.7 (20.1) to 6.1 (4.5). Significant reductions in diastolic blood pressure (DBP) and mean arterial pressure (MAP) were found for the 20-h periods, and systolic blood pressure (SBP), DBP, and MAP while asleep. The mean values were 79.5 (5.5) to 74.6 (6.0) for DBP and 95.9 (5.4) to 91.2 (5.9) for MAP, for over a 20-h period, and 118.4 (10.0) to 113.7 (9.1) for SBP, 71.6 (8.0) to 67.2 (7.9) for DBP, and 88.4 (8.0) to 83.9 (7.5) for MAP, while asleep. This study suggests that successful OSA treatment with an OA may also be beneficial to lower blood pressure in OSA patients, as previously suggested for nasal continuous positive airway pressure therapy. This study was conducted in the Division of Orthodontics, The University of British Columbia, Canada     

Prospective evaluation of an oral appliance in the treatment of obstructive sleep apnea syndrome

The purpose of this study was to investigate the effects of an oral appliance (OA), with and without mandible advance, in the treatment of obstructive sleep apnea syndrome (OSA). Twenty-four patients diagnosed with OSA agreed to participate in this study. The patients were treated for 3 months (with a removable soft elastic silicone positioner customized with thermoplastic silicone and with a 5-mm opening). Patients were selected, using a randomized design, to receive an OA model either with (12 patients) or without advance (12 patients). Before treatment, a snoring questionnaire, the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), the Functional Outcomes of Sleep Questionnaire (FOSQ), the Epworth Sleepiness Scale (ESS), and polysomnography were completed. Fifteen subjects completed the protocol (13 men, two women). With respect to basal values, the mandible-advanced OA group presented a decrease in the mean apnea–hypopnea index (AHI) (33.8±4.7 versus 9.6±2.1; p<0.01), number of arousals per hour (33.8±13.9 versus 16.0±1.5; p<0.05), ESS score (14.7±5.1 versus 5.1±1.9; p<0.05), snoring score (15.4±1.9 versus 10.1±3.2; p<0.05), and total FOSQ score (78.1±22.6 versus 99.3±14.4; p<0.05). After treatment, the non-advanced group presented a decrease in the mean AHI (24.0±12.2 versus. 11.7±7.9; p<0.05). However, no significant differences were found in the number of arousals per hour, ESS score, snoring, and total FOSQ score in the non-advanced group. Neither study group showed significant difference in mean SF36 scores. Oral appliances, especially those that advance the mandible, offer an effective treatment for OSA.     

Condyle displacement in obstructive sleep apnea patients with oral appliance

目的 明确阻塞性睡眠呼吸暂停综合征(obstructive sleep apnea,OSA)患者戴入治疗有效的口腔矫治器后髁状突的位置变化.方法 选取21例使用口腔矫治器成功治疗的OSA患者参加研究,采用经颅咽方向投照双侧颞下颌关节的方法摄取闭口位、最大开口位及戴有效的口腔矫治器后双侧颞下颌关节的数字化X线片.测量髁状突的位置并作三个不同下颌位置的比较,对髁状突位置的变化及戴用口腔矫治器后的疗效变化作相关分析.结果 三个髁状突位置明显不同.患者戴入治疗有效的口腔矫治器后髁状突的最上点座标为X(-1.21±1.98)mm,Y(-0.68±1.08)mm.髁状突位置的变化与口腔矫治器疗效的变化无明显相关性,x值的相关系数为r=0.057,y值的相关系数为r=0.024.结论 戴入有效的口腔矫治器后髁状突的最上点为靠近于颞下颌关节的结节点.     

Effect of vertical dimension on efficacy of oral appliance therapy in obstructive sleep apnea

The aim of this study was to assess the effect of bite opening induced by a mandibular advancement splint (MAS) on efficacy and side effects in the treatment of obstructive sleep apnea. In a randomized crossover fashion, 23 adult patients received either MAS-1 (4 mm of interincisal opening) or MAS-2 (14 mm of interincisal opening) for 2 weeks, followed by the alternate treatment for 2 weeks, with an intervening 1-week washout. Complete response was defined as a resolution of symptoms and a reduction in apnea/hypopnea index (AHI) to less than 5 per hour. Partial response was defined as improved symptoms and a reduction in AHI of 50% or more, with the AHI remaining at a value of 5 or more per hour. Both MAS-1 and MAS-2 produced similar reductions in mean (+/- SEM) AHI from baseline: 21 +/- 2 versus 8 +/- 1/hour and 21 +/- 2 versus 10 +/- 2/hour, respectively (p < 0.001). Either complete response or partial response occurred in 74 and 61% of patients with MAS-1 and MAS-2, respectively. Subjective improvements were reported with both appliances by the majority of patients. Patients preferred MAS-1 (78 versus 22%, p = 0.007). This study suggests that the amount of bite opening induced by MAS does not have a significant impact on treatment efficacy but does have an impact on patient acceptance.     

The multisystemic effects of oral appliance therapy for obstructive sleep apnea: A narrative review

Obstructive sleep apnea (OSA) is a chronic condition accompanied by repeated obstruction of the upper airway during sleep despite respiratory efforts, resulting in intermittent hypoxemia, altered sleep structure, and sympathetic activation. Previous studies have shown a significant association between OSA and general health issues such as cardiovascular diseases, endocrine disorders, neurocognitive function decline, and poor quality of life. Continuous positive airway pressure (CPAP) has been considered as the first line treatment for OSA. However, accumulating evidence supports the role of oral appliance (OA) therapy, including mandibular advancement devices, as an alternative option for snoring and OSA patients who do not comply with or refuse CPAP usage. Despite a generally favorable outcome of OA therapy for OSA related respiratory indices, studies focusing on the impact of systemic effects of OA therapy in OSA patients are relatively scarce compared with the extensive literature focusing on the systemic effects of CPAP. Therefore, this article aimed to provide an overview of the current evidence regarding the multisystemic effects of OA therapy for OSA.     

Videoendoscopic diagnosis for predicting the response to oral appliance therapy in severe obstructive sleep apnea

Purpose

In treatment for obstructive sleep apnea (OSA), oral appliance (OA) therapy is indicated in patients with mild–moderate OSA. However, since patients with severe OSA in whom OA therapy was effective have also been reported, it may not be possible to determine indications for OA therapy based on the severity alone. The purpose of this study was to determine indications for OA therapy using endoscopy during wakefulness in patients with severe OSA.

Methods

The subjects consisted of 36 patients (27 males and 9 females) diagnosed with severe OSA using all-night polysomnography. In each patient, a nasoendoscope was inserted in a horizontal position during nasal breathing, and morphological changes in the airway of the velopharynx and oro-hypopharynx with mandibular advancement were evaluated.

Results

With mandibular advancement, the oro-hypopharynx was widened in all patients while the velopharynx was widened in 29 patients, but not in 7. The apnea hypopnea index (AHI) reduction rate after OA application was 79.8 % (SD, 13.0 %) in the group with and 40.6 % (SD, 27.0 %) in the group without velopharyngeal widening, being significantly different between the two groups. In the group showing velopharyngeal widening, evaluation of the direction of widening revealed two types: the “all-round type”, which is circumferential widening in the anteroposterior–lateral directions, and the “lateral dominant type”, which is widening mainly in the lateral direction. The AHI reduction rate was 80.1 % (SD, 15.0 %) for the all-round type and 79.3 % (SD, 10.6 %) for the lateral dominant type showing no significant difference.

Discussion

(1) Concerning indications for OA therapy, findings in the velopharynx rather than those in the hypopharynx may be important. (2) The effects of OA therapy can be expected in the presence of velopharyngeal widening irrespective of its direction. Thus, to determine whether OA therapy is indicated, endoscopic evaluation of morphological changes in the velopharynx with mandibular advancement may be important.     

Occlusal and skeletal effects of an oral appliance in the treatment of obstructive sleep apnea

STUDY OBJECTIVE:s: Oral appliances (OAs) are considered to be a treatment option for patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). Although the effectiveness of these appliances has been evaluated in a number of clinical trials, there are few follow-up studies concerning the dental and skeletal side effects that, theoretically, could be caused by OAs. We sought to examine the long-term skeletal and occlusal effects of a nocturnally worn activator in adult patients treated for OSAHS. DESIGN: We analyzed the dental casts and lateral radiographs of 34 patients (mean age, 52.9 years; SD, 9.6 years; range, 27.1 to 64.6 years) before initiating treatment and after at least 24 months of treatment (mean length of treatment, 29.6 months; range, 24.1 to 43.5 months; SD, 5.1 months). The OA was worn by each patient 6 to 8 h nightly for > 5 days per week. SETTING: Department of Orthodontics, Dental Medical School, Freiburg, Germany. MEASUREMENTS AND RESULTS: Follow-up polysomnography studies confirmed improved breathing parameters with the use of OAs. A statistically significant alteration in the occlusion was found. The anteroposterior position of the molars and the inclination of the upper and lower incisors were changed. No skeletal changes in the position of the mandible were noted. CONCLUSIONS: The data suggest that in addition to control polysomnographic examinations, regular dental follow-up visits are mandatory when lifelong OSAHS treatment with an OA is being considered for patients with obstructive sleep apnea/hypopnea.     

Use of flow-volume curves to predict oral appliance treatment outcome in obstructive sleep apnea

BACKGROUND: It has been recognized that mandibular advancement splint (MAS) treatment is effective in some, but not all, patients with obstructive sleep apnea (OSA). Hence there is a need for a simple and reliable clinical tool to assist in the differentiation of treatment responses. We hypothesized that abnormalities of flow-volume curves, together with other clinical variables, may have clinical utility in the prediction of MAS treatment outcome. METHODS: Fifty-four patients with known OSA underwent MAS treatment. Expiratory and inspiratory flow-volume curves were measured in the erect and supine positions to derive midinspiratory flow (MIF(50)) and the ratio of expiratory to inspiratory flow at 50% of vital capacity (MEF(50):MIF(50)). Multivariable logistic regression was performed to identify additional significant clinical variables in the prediction of treatment outcome. RESULTS: The mean (+/- SD) apnea-hypopnea index (AHI) in 35 responders was significantly reduced from 28.9 +/- 13.7 to 6.7 +/- 5.8/hour (p<0.001). In 19 nonresponders there was no significant change in AHI. MIF(50) was lower (6.04 +/- 1.80 vs. 6.88 +/- 1.08 L/second; p=0.035) and the MEF(50):MIF(50) ratio was higher (0.82 +/- 0.23 vs. 0.61 +/- 0.15; p=0.001) in responders than nonresponders. Logistic regression analysis revealed that the MEF(50):MIF(50) ratio was the most important predictive factor for MAS treatment outcome, but that body mass index, age, and baseline AHI were also contributory. CONCLUSIONS: These data suggest that flow-volume curves, in combination with other factors such as body mass index, age, and baseline AHI, may have a useful clinical role in the prediction of treatment outcome with MAS.     

Effect of oral appliance therapy on blood pressure in Japanese patients with obstructive sleep apnea

Objective: Obstructive sleep apnea (OSA) treatment in patients with OSA and hypertension reduces blood pressure (BP). Oral appliance (OA) therapy is nowadays prescribed for patients with mild to moderate OSA. This study aimed to clarify the effect of OA therapy on BP reduction in Japanese patients with mild to moderate OSA. Methods: Polysomnography was employed to detect sleep-disordered breathing. Totally, 237 patients without cardiac and/or cerebrovascular diseases and those with apnea-hypopnea index (AHI) ≥ 5/h–< 30/h were enrolled. Office BP change after receiving 8–12 weeks of OA therapy was assessed and the factors related to the degree of BP reduction were analyzed. Results: The study patients consisted of 188 men and 49 women, the mean age was 54.7 ± 13.2 years old, and the body mass index (BMI) was 24.6 ± 3.4 kg/m². The antihypertensive effect of OA therapy resulted in systolic BP (SBP) ?2.4 ± 14.8 (p = 0.078) and diastolic BP (DBP) ?2.0 ± 11.7 mm Hg (p = 0.045) in all patients. SBP before OA therapy played a significant role in the degree of SBP reduction (β = ?0.597, p < 0.001), whereas DBP before OA therapy was a significant factor of the degree of DBP reduction (β = ?0.522, p < 0.001). Conclusion: A certain time period of OA therapy effected BP reduction in mild to moderate OSA patients without cardiac and/or cerebrovascular diseases. Its antihypertensive effect was greater in OSA patients whose BP was higher before receiving OA therapy.     

Supine cephalometric analyses of an adjustable oral appliance used in the treatment of obstructive sleep apnea

Objective: To investigate the effects of the Klearway^TM appliance on the upper airway in patients with obstructive sleep apnea (OSA) in the supine position.Methods: Sixteen subjects (12 males and 4 females) were recruited cruited on the basis of baseline polysomnography with a documented Apnea and Hypopnea Index (AHI)>15 per hour. A second overnight sleep study was performed for each subject with the appliance in place. Baseline supine cephalometry was performed for each subject before the initial insertion of the appliance, and follow-up supine cephalometry was undertaken with the appliance in place.Results: The polysomnographic variables improved significantly, and the mean changes in overbite and overjet were 5.15 mm and 6.26 mm after insertion of the Klearway^TM appliance. The supine sagittal cross-sectional areas of the pharynx and the tongue significantly increased, while the linear distance from the hyoid position to the mandibular plane or the RGN-C3 line significantly decreased after insertion of the appliance. The ratio of the vertical pharyngeal length to the sagittal cross-sectional area of nassopharynx or tongue decreased significantly. When the subjects were evaluated on the basis of the after-insertion AHI, the group with good response (n=11) was found to be significantly younger than the group with the poor response (n=5). Similarly, the good responders revealed less prominent chins, larger tongue heights, and an increase in hypopharyngeal sagittal cross-sectional area after insertion of the appliance. There was a significant correlation between the improvement in AHI (%) and the supine middle airway space (r=−0.52, p<0.05).Conclusion: The mechanical effect of the Klearway^TM appliance on the upper airway and the stabilization of jaw posture may be important determinants of the efficacy of the appliance.     

Severe obstructive sleep apnea alleviated by oral appliance in a three-year-old boy

This clinical report describes a 3.5-year-old boy suffering from chronic daytime fatigue, accumulated snoring and dramatically appearing apnea during sleep. Oxycardiorespirography revealed a breathing pattern similar to repetitive obstructive apnea and an oxygen saturation periodically dropping to 80%. During tidal breathing, fiberoptic bronchoscopy showed aspiration of the aryepiglottic folds and the epiglottis during inspiration. Adenotonsillar hypertrophy was excluded. Due to the acknowledged side effects from various surgical approaches and nasal continuous positive airway pressure, a removable, functional Fraenkel II oral appliance was applied during sleep. Clinical assessment demonstrated resolution of the main respiratory symptoms, and oxycardiorespirography revealed a fundamental reduction in periodic obstructive apnea and desaturation. In conclusion, we consider the use of an oral functional appliance for severe obstructive sleep apnea in children to be a valuable alternative to other treatment methods.     

Severe obstructive sleep apnea treatment with oral appliance: the impact on obstructive,central and mixed events

Purpose

The aim of this study is to evaluate the effectiveness of two types of oral appliance (OA) in the treatment of severe obstructive sleep apnea syndrome (OSAS) and their impact on the reduction of obstructive, central and mixed apneas.

Methods

Forty-eight patients suffering from severe OSAS with a history of non-adherence to positive airway pressure therapy were treated with OA (lingual orthosis and combined orthosis). Polysomnography exams were performed before and after treatment. Computed tomography and cephalometric radiography were requested for all patients to evaluate the titrated position of the OA and the airspace obtained. Statistical tests used the Minitab, version 17, program. The level of statistical significance was 5%.

Results

Before treatment, the mean AHI was 56.3 ± 19.1 events/h. It decreased to 8.1 ± 5.2 after the OA titration (p ≤ 0.001). There was a significant reduction in obstructive events from 43.0 ± 20.2 to 7.1 ± 4.6 events/h (p ≤ 0.001). The reduction in central events after OA treatment was also significant (from 5.1 ± 9.3 to 0.8 ± 1.9 events/h; p ≤ 0.001), whereas that in mixed events decreased from 6.4 ± 9.5 to 0.1 ± 0.3 events/h (p ≤ 0.001). The minimum oxygen saturation also showed significant improvement after treatment (p ≤ 0.001). There was no statistically significant difference between both OA with respect to central events (p = 0.22) or mixed events (p = 0.98).

Conclusion

The treatment was effective in reducing obstructive events which were evaluated through the AHI and minimum oxygen saturation. The oral appliances also normalized central and mixed events among patients with severe OSAS.

     

Towards a prediction model for drug-induced sleep endoscopy as selection tool for oral appliance treatment and positional therapy in obstructive sleep apnea

Purpose

To evaluate the effect of different passive maneuvers on upper airway patency during drug-induced sleep endoscopy (DISE) compared to recent literature on treatment outcomes of positional therapy (PT), oral appliance therapy (OAT), and combined treatment in obstructive sleep apnea (OSA) patients.

Methods

A retrospective, single-center cohort study including a consecutive series of 200 OSA patients. All patients underwent DISE with and without manually performed jaw thrust and lateral head rotation by using the VOTE classification. The effect of these maneuvers were analyzed by using the sum VOTE score comparing non-positional (NPP) and positional OSA patients (PP).

Results

Two hundred patients were included (80.5% male) with a mean age of 50.1?±?11.7 years, a BMI of 27.0?±?3.1 kg/m², and a median AHI of 19.2 events per hour. Forty-four percent of the patients were NPP; of the remaining 56%, 34% was diagnosed with supine isolated and 66% with supine predominant POSA. Manually performed jaw thrust showed a reduction of sum VOTE score of 66.7% in all subgroups. The effect of lateral head rotation was a reduction of 33.3% in NPP and supine predominant PP and 50% in supine isolated PP. Combining these maneuvers a reduction of more than 75% was seen in all patients.

Conclusions

The present model leaves room for improvement. The effect of manually performed jaw thrust is greater and the effect of lateral head rotation alone is less than what was expected compared to recent literature on treatment outcome of OAT, PT, and combined treatment.

     

戴用口腔矫治器后阻塞性睡眠呼吸暂停患者的睡眠结构变化

目的了解戴用下颌前移口腔矫治器后阻塞性睡眠呼吸暂停疾病(OSAD)患者的睡眠结构变化。方法选取行下颌前移口腔矫治器治疗的OSAD患者61例,接受口腔矫治器治疗前后均行多导睡眠图检查。将患者分为治疗后成功组52例及不成功组9例,对两组治疗前后的睡眠分期比率及疗效进行比较。结果成功组治疗前后S3、AI、HI、AHI、LSpO_2、最长呼吸暂停时间比较差异有统计学意义(P 0. 05)。不成功组治疗前后AHI、最长呼吸暂停时间比较差异有统计学意义(P 0. 05)。两组治疗后呼吸参数AI、AHI、LSpO_2比较差异有统计学意义(P 0. 05)。结论戴用下颌前移口腔矫治器治疗成功的OSAD患者深睡眠百分比略有增加。     

Combined oral appliance and positive airway pressure therapy for obstructive sleep apnea: a pilot study

Background  

The high efficacy of continuous positive airway pressure (CPAP) in treating obstructive sleep apnea (OSA) is limited by poor compliance often related to pressure intolerance. Mandibular advancement devices (MADs) are proven alternative therapy although not universally effective. A combination of nasal CPAP and MAD may provide another option for CPAP-intolerant patients with incomplete response to MAD.     

Systematic assessment of the impact of oral appliance therapy on the temporomandibular joint during treatment of obstructive sleep apnea: long-term evaluation

Objective  

The aim of the present study was to evaluate the symptoms of temporomandibular dysfunction (TMD) in patients with obstructive sleep apnea treated with long-term use of an oral appliance (OA) using a questionnaire based on the Helkimo Anamnestic Dysfunction Index. A further aim of the study was to evaluate the presence of daytime sleepiness using the Epworth Sleep Scale (ESS) and otologic symptoms.