Selecting sleep-disordered-breathing appliances. Biomechanical considerations

Craniofacial morphology/phenotypes influence on mandibular range of movement in the design of a mandibular advancement device

Background

The mandibular opening path movements have different directions according to the craniofacial morphology of the patient but always downward and backward, therefore increasing the collapse of the upper airway. The aim of this work is to determine if there is a relationship between the craniofacial morphology and the mandibular movement to help understand the impact on the mandibular position.

Methods

52 students with full permanent dentition aged 19 to 23 years (mean 21.3 SD 1.7; 29 females and 23 males), participated in the study. Each subject had a lateral cephalometric radiograph taken. The opening angle was determined for two levels of vertical openings at 5 and 10 mm.

Results

The opening angle showed a greater variability between subjects ranging from 63.15 to 77.08 for 5 mm angle and from for 61.65 to 75.72 for the 10 mm angle. Differences of facial phenotypes was evident when comparing the individual dissoccluding angle of the low angle horizontal pattern and high angle vertical pattern.

Conclusions

The opening angle is related to craniofacial morphology with higher vertical anterior and shorter anteroposterior faces having a more horizontal path of mandibular movement than shorter vertical anterior and longer anteroposterior subjects who have a more vertical path.

Antero-posterior mandibular position at different vertical levels for mandibular advancing device design

INTRODUCTION

Mandibular Advancement Devices (MAD) have been reported to be an alternative treatment to CPAP in moderate to severe obstructive sleep apnea (OSA) cases. The design of MAD has a major influence on its success rate on the patient, and design features that have an influence on efficacy, tolerance, and compliance. The aim of this study was to determine the range of mandibular protrusion at different vertical points; 2, 5, 8 and 11 mm in a young adult population.

METHODS

Fifty two students aged 19 to 23 years (mean 21.3 ± 1.7; 29 females and 23 males), with full permanent dentition participated in the study. The absolute range of maximal mandibular protrusion and retrusion was measured (mm) with the use of the George Gauge. Descriptive statistics, ANOVA and paired t-test using SPSS were used.

RESULTS

Range of mandibular advancement was possible to be determined for the 4 levels of vertical opening with the gauges: 2 mm fork mean mandibular advance 13,10 mm ± 0.604; 5 mm mean 11.98 mm ± 1.075; 8 mm mean 11.20 mm ± 1.369; 11 mm mean 9.87 mm ± 1.886. No significant differences were found between class I, II, and III.

CONCLUSIONS

There is an impact of increased inter-incisal distance of effective mandibular protrusion when constructing a MAD. As vertical dimension increases the mandible rotates posteriorly and places itself in a more retrusive location, and the range of mandibular advancement reduces (0.3 mm for every 1 mm of vertical increase).

Titration technique using endoscopy for an oral appliance treatment of obstructive sleep apnea

The degree of mandibular protrusion for an oral appliance (OA) should be customized for each patient with obstructive sleep apnea (OSA). This article describes the mandibular titration technique for OAs to effectively treat OSA by using endoscopy to evaluate the change in the airway at the velopharynx. This technique may minimize the degree of mandible protrusion and contribute to both the efficacy of and compliance with OA therapy.

A randomized, controlled trial of positional therapy versus oral appliance therapy for position-dependent sleep apnea

OBJECTIVE

To compare the effectiveness of positional therapy (PT) with the sleep position trainer (SPT) to oral appliance therapy (OAT) in patients with mild-to-moderate positional obstructive sleep apnea (POSA).

METHODS

Multicenter, prospective, randomized, controlled trial. Patients with mild-to-moderate POSA (apnea-hypopnea index (AHI) ≥5 ≤ 30/hour sleep) were randomized for PT or OAT. Polysomnography was repeated after 3 months. Efficacy, adherence, mean disease alleviation (MDA), quality of life, dropouts and adverse events were evaluated.

RESULTS

A total of 177 patients were screened for the study; 99 underwent randomization and 81 completed the study. Intention-to-treat (ITT) analysis of median [IQR] AHI showed a reduction in the PT group from 13.0 [9.7-18.5] to 7.0 [3.8-12.8], p < 0.001 and in the OAT group from 11.7 [9.0-16.2] to 9.1 [4.9-11.7], p < 0.001. Mean adherence (≥4 h/night, ≥5 days/week) was 89.3 ± 22.4% for SPT versus 81.3 ± 30.0% in OAT patients, p = 0.208.

CONCLUSIONS

Oral appliance therapy and positional therapy were equally effective in reducing the median AHI in patients with mild-to-moderate POSA. The results of this study have important implications for future OSA treatment guidelines and daily clinical practice. CLINICALTRIALS.

GOV NUMBER

NCT02045576.

Efficacy of custom made oral appliance for treatment of obstructive sleep apnea

INTRODUCTION

oral appliance for the treatment of OSA is considered as an effective, low-risk alternative to CPAP. Demand for oral appliance increases as an alternative for those who cannot tolerate CPAP and refuse surgery. Oral appliances uses the traditional methods to advance the mandible thus modify the posture and their by enlarge the airway or otherwise reduce the collapsibility.

AIMS AND OBJECTIVES

The main objective of this study was to evaluate the efficacy of custom made oral appliance on sleep characteristics of OSA patients.

MATERIALS AND METHODS

Polysomnography was done on 15 patients of 24-60 years of age before (T1), and after the delivery of the custom made oral appliance (T2).

STATISTICAL ANALYSIS

Paired t tests were performed to determine the significance of change in the polysomnographic and cephalometric variables. P < 0.05 was considered as significant.

RESULTS

All patients with oral appliance showed an improvement in sleep parameters with an increase in sleep efficiency, and desaturation index with the use of oral appliance. ESS and cephalometric findings showed improvement in the sleep apnea in concordance with the sleep parameters.

CONCLUSIONS

Custom made oral appliance is a useful treatment option for improving quality of sleep and can be considered as an alternative treatment modality.

Effects of varying mandibular protrusion and degrees of vertical opening on upper airway dimensions in apneic dentate subjects

INTRODUCTION

Despite numerous studies investigating the dimensional and therapeutic effects of mandibular advancement splints (MASs), data regarding the effects of differently designed individual and non-adjustable MASs on the upper airway in fully dentate apneic subjects in the sagittal plane including comparison of these effects with a placebo device are sparse. The present study aimed to determine the dimensional changes in the sagittal plane created by differently designed MASs in the upper airway in fully dentate apneic subjects and to compare these changes with the effects of a placebo device.

MATERIALS AND METHODS

Magnetic resonance (MR) images of 9 dentate apneic subjects with 5 differently designed MASs and without a MAS were obtained. We measured the area of the entire pharynx (velopharynx, oropharynx, hypopharynx) on these MR images and compared the dimensional changes.

RESULTS

The dimensional changes triggered by two specific MASs (75% of the maximum mandibular protrusion with 5 mm vertical opening, and 75% of the maximum mandibular protrusion with 10 mm of vertical opening) in the entire pharynx in the sagittal plane were statistically significant compared to the other MASs (p < 0.05). The MAS effecting 75% of the maximum mandibular protrusion and 10 mm of vertical opening created a significant dimensional increase only in the velopharyngeal area among the three pharyngeal sites (p ≤ 0.003).

CONCLUSION

While the degree of mandibular protrusion created by the MAS affects the dimensions of the upper airway, the degree of the vertical opening exerts no significant dimensional effect in the sagittal plane in fully dentate apneic patients. The mandibular protrusion effect is comparatively larger in the velopharyngeal region.

Treatment of obstructive sleep apnea with oral appliances

BACKGROUND

The purpose of this study was to evaluate the effectiveness of mandibular advancement devices (MADs) for treatment of obstructive sleep apnea syndrome (OSAS) compared with the results obtained with a placebo device in accordance with the following indicators: apnea hypopnea index (AHI) per hour of sleep, apnea index (AI) per hour of sleep, mean oxyhemoglobin saturation, sleep efficiency, and percentage of rapid eye movement (REM) sleep.

METHODS

This is a controlled, prospective longitudinal study with a follow-up time of 10.5 months. Nineteen patients (8 females and 11 males) with mean age 48.6 years (SD 9.6) were selected for the study. The sample was randomized in terms of device use, and the evaluation design was double blind. A total of 57 polysomnography tests were studied (at baseline, after the use of a MAD, and after the use of placebo). The following variables were assessed: AHI, AI, mean oxyhemoglobin saturation, percentage of REM sleep, and sleep efficiency. Wilcoxon and Mann-Whitney tests were used for evaluating data (p<0.05).

RESULTS

Reductions from 16.3 to 11.7 in AHI and from 5.7 to 3.8 in AI were observed after MAD use. During the use of placebo, AHI increased from 16.3 to 19.6, and AI from 5.7 to 7.5. The other indexes showed no statistically significant differences.

CONCLUSIONS

Treatment with oral appliances, i.e., MADs, can be an effective alternative for mild and medium-to-moderate OSAS, but requires strict monitoring due to differences in individual response to this therapy.

Use of an individual mandibular advancement device for an?obstructive sleep apnoea patient with facial paralysis: a short-term follow-up case report

This case report aimed to describe the fabrication procedure and treatment efficacy of an individual, one-piece, non-adjustable mandibular advancement device (MAD) for a moderate obstructive sleep apnoea patient with facial paralysis (FP). Mandibular advancement device was fabricated with autopolymerising acrylic resin. The intermaxillary relations were recorded such as to fix the mandible at a protruded position with increased vertical dimension. Initial evaluation of the MAD was made with axial magnetic resonance imaging and polysomnography on the first day of usage. Following evaluations were made on the third and sixth month. After a follow-up period of 6 months, Apnoea/Hypopnea Index (AHI) significantly decreased from 26·7 to 3·0. However, the average oxygen saturation did not improve as expected initially. The MAD therapy decreased the AHI scores of a patient with FP. At the end of a follow-up period of 6 months, the patient did not report any serious complaint except temporary tooth pains.

Effects of an oral appliance with different mandibular protrusion positions at a constant vertical dimension on obstructive sleep apnea

The aim of the study was to assess the influence of four mandibular protrusion positions, at a constant vertical dimension, on obstructive sleep apnea (OSA). Seventeen OSA patients (49.2 +/- 8.5 years) received an adjustable mandibular advancement device (MAD). The patients underwent four polysomnographic recordings with their MAD in situ at, in random order, 0%, 25%, 50%, and 75% of the maximum protrusion. The mean apnea-hypopnea index (AHI) values of the patients differed significantly between the protrusion positions (P < 0.000). The 25% protrusion position resulted in a significant reduction of the AHI with respect to the 0% position, while in the 50% and 75% positions, even lower AHI values were found. The number of side effects was larger starting at the 50% protrusion position. We therefore recommend coming to a weighted compromise between efficacy and side effects by starting a MAD treatment in the 50% protrusion position.

Recognizing and managing obstructive sleep apnea in primary care

OBJECTIVE

This review aims to impart information regarding recognition of obstructive sleep apnea (OSA) and associated excessive sleepiness (ES) in the primary care setting in order to provide optimal care to patients with this common but serious condition. This review will also discuss the prevalence and treatment of depression in patients with OSA.

DATA SOURCES

A MEDLINE search of articles published between 1990 and 2008 was conducted using the search terms obstructive sleep apnea AND excessive sleepiness, obstructive sleep apnea AND depression, and obstructive sleep apnea AND primary care. Searches were limited to articles in English concerned with adult patients.

STUDY SELECTION

In total, 239 articles were identified. Articles concerning other sleep disorders and forms of apnea were excluded. The reference lists of identified articles were searched manually to find additional articles of interest.

DATA SYNTHESIS

Primary care physicians can aid in the diagnosis of OSA and associated ES by being vigilant for lifestyle and physical risk factors associated with this condition. In addition, primary care physicians should maintain a high level of clinical suspicion when presented with illnesses that are commonly comorbid with OSA, such as psychiatric disorders and depression, in particular. Conversely, assessment of patients with OSA for common comorbidities may also improve a patient's prognosis and quality of life.

CONCLUSIONS

Primary care physicians play a vital role in recognizing OSA and ES. These clinicians are crucial in supporting their patients during treatment by ensuring that they have clear, concise information regarding available therapies and the correct application and maintenance of prescribed devices.

Current trends in the treatment of obstructive sleep apnea

Obstructive sleep apnea (OSA) is a condition of partial or complete upper airway obstruction leading to increased resistance to airflow and potential cessation of breathing during sleep. Effective treatment of OSA is challenging and there has been greater recognition by the medical and dental disciplines. By understanding the rationale, indications, benefits, risks and success of the various treatment options available, clinicians will be able to make more informed treatment recommendations in patient management.

Evaluation of an oral mandibular advancement titration appliance

OBJECTIVES

To determine whether a manually adjustable oral mandibular advancement titration appliance (EMA-T) predicts successful long-term treatment with an oral mandibular advancement appliance (MAA).

STUDY DESIGN

At an academic medical center, 21 adults with obstructive sleep apnea (AHI > 10 events/hr) performed baseline, titration, and MAA (Klearway) polysomnograms. During the titration polysomnogram with EMA-T, the mandible was advanced until apneas and hypopneas were eliminated or maximum tolerable advancement was reached. Participants then used the MAA at home and, once the mandible was advanced to the amount determined during the titration polysomnogram, a polysomnogram with MAA was performed.

RESULTS

Mean AHI at baseline was 33.5 +/- 18.3 (SD) events/hr. During the titration polysomnogram, 9 subjects achieved an AHI < 10 and at least a 50% reduction in AHI. None of the subjects met these criteria on the MAA polysomnogram.

CONCLUSIONS

EMA-T lowered the AHI to efficacious levels in 43% of patients but this acute response did not predict the efficacy of long-term MAA treatment.

Multidisciplinary management of the airway in a trauma-induced brain injury patient

Laryngomalacia occurs in some brain injury patients secondary to global muscle hypotonia. Surgical therapies for epiglottis prolapse have centered around removal or reshaping of the epiglottis. This approach has brought mixed success and frequent complications. We present a case that demonstrates successful nonsurgical treatment of a 33-year-old male brain injury patient with moderate obstructive sleep apnea that is believed to be a consequence of post-brain injury nocturnal epiglottis prolapse. The presence of a tracheostomy performed at the time of emergency surgery had become an emotional and physical barrier to our patient's recovery. The tracheostomy could only be reversed if the obstructive sleep apnea disorder could be managed in an alternative fashion. A titratable mandibular repositioning appliance was prescribed and its effectiveness was demonstrated with nasolaryngoscopy and polysomnography. After initially fitting the oral appliance, a period of accommodation and gradual protrusive adjustments was allowed. Subsequent confirmation polysomnography demonstrated improvement, but not suitable resolution, of disordered breathing events. However, an additional 1.25-mm protrusive titration of the oral appliance during the course of the confirmation polysomnogram led to therapeutic success. The patient's tracheostomy was subsequently reversed with significant quality of life benefits.

Efficacy and co-morbidity of oral appliances in the treatment of obstructive sleep apnea-hypopnea: a systematic review

The Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS) is a common sleep-related breathing disorder characterized by repetitive obstructions of the upper airway during sleep. Modification of pharyngeal patency by Oral Appliance (OA) therapy has been suggested as an alternative to various treatment modalities for OSAHS. To determine the evidence base with respect to the efficacy and co-morbidity of OA therapy in OSAHS, we conducted a systematic review of the available literature. Primary outcome measures were the reduction in number of upper-airway obstructions and co-morbidity related to the craniomandibular or craniofacial complex, respectively. Eligible studies regarding efficacy were independently assessed by two assessors using a quality assessment scale. Effect sizes of methodologically sound studies were calculated. In identical interventions, effect sizes were pooled with the use of a random-effects model. Given the scarcity of controlled studies related to co-morbidity, appraisal was confined to a description of eligible studies. Sixteen controlled trials related to efficacy were identified. With respect to the primary outcome measure, OA therapy was clearly more effective than control therapy (pooled effect size, -0.96; 95% confidence interval [CI], -1.49 to -0.42) and possibly more effective than uvulopalatopharyngoplasty. Although patients generally preferred OA therapy, improvement of respiratory variables, such as the number of upper-airway obstructions, was usually better in Continuous Positive Airway Pressure (CPAP) therapy (pooled effect size, 0.83; 95% CI, 0.59 to 1.06). Moreover, specific aspects related to OA design may influence patient-perceived efficacy and preference. Twelve patient-series and one controlled trial related to co-morbidity were identified. Analysis of the data suggests that OA therapy may have adverse effects on the craniomandibular and craniofacial complex. Although CPAP is apparently more effective and adverse effects of OA treatment have been described, it can be concluded that OA therapy is a viable treatment for, especially, mild to moderate OSAHS. Controlled studies addressing the specific indication and co-morbidity of OA therapy are warranted.

Effect of titrated mandibular advancement and jaw opening on the upper airway in nonapneic men: a magnetic resonance imaging and cephalometric study

The aim of this study was to examine adaptive changes in the cross-sectional area of the upper airway during mandibular advancement and jaw opening and to explore whether these changes are directly related to morphologic features of the mandible. Fourteen nonapneic men participated in this study. A custom-made oral device was used to keep the mandible at 0% (F(0)V(0)), 50% (F(50)V(0)), 75% (F(75)V(0)), or 100% (F(100)V(0)) of maximum advancement, and at 50% (F(75)V(50)), 75% (F(75)V(75)), or 100% (F(75)V(100)) of maximum gape at F(75)V(0). Magnetic resonance imaging was used to investigate differences in the upper-airway cross-sectional area in these 7 positions. To eliminate excessive individual variation, changes in the mean (mean%) and minimum (min%) cross-sectional area of the upper airway were calculated as percentages of those at F(0)V(0). Cephalograms were taken to analyze morphologic features of the mandible. A dose-dependent change was seen when the mandible was advanced. The min% in F(100)V(0) was significantly greater than those in F(50)V(0) and F(75)V(0). The change in the upper airway size varied between subjects during jaw opening. At F(75)V(0), the min% of the whole upper airway was significantly associated with morphologic features of the mandible, such as the mandibular plane angle and lengths of the mandibular body and ramus.

The efficacy of a mandibular advancement splint in relation to cephalometric variables

The efficacy of a titratable mandibular advancement splint (MAS) for the management of obstructive sleep apnea (OSA) was investigated in relation to supine cephalometric variables. Fourteen adults with diagnosed OSA were recruited following an initial polysomnogram. Supine cephalographic radiographs were taken at baseline and subjects wore the MAS nightly for 6 to 8 weeks. The polysomnogram and cephalogram were repeated with the MAS at maximal titration. The MAS resulted in complete or partial treatment response in all subjects as measured by the improvement in mean apnea/hypopnea index (AHI) (baseline AHI 34 +/- 22/hr, with MAS 10 +/- 5/hr; p = 0.001). The perpendicular distance between the hyoid bone and the mandibular plane (HYML) measured in awake subjects decreased with the MAS (baseline HYML 25.3 +/- 7.8 mm, with MAS 16.5 +/- 9.6 mm; p = 0.002). Baseline HYML was the only cephalometric variable associated with a successful clinical outcome. It was strongly linked to improvements in AHI (adjusted R(2) = 0.37, p = 0.012) and arousals (adjusted R(2) = 0.455, p = 0.005). We conclude that the MAS is an effective therapy for OSA and baseline HYML is an important predictor of improvement. Improvements in AHI may be explained by the MAS maintaining the new or existing relationship of the hyoid and its surrounding structures, thus preventing obstruction in the upper airway during sleep.

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.

An individually adjustable oral appliance vs continuous positive airway pressure in mild-to-moderate obstructive sleep apnea syndrome

BACKGROUND

For the treatment of nonsevere obstructive sleep apnea syndrome (OSAS), mandibular advancement devices (MADs) are employed as an alternative to nasal continuous positive airway pressure (CPAP) therapy. However, very few specific data on the effectiveness of MADs in this group of patients are available. We therefore compared an individually adjustable intraoral sleep apnea device (ISAD) that permits movements of the lower jaw in three dimensions, with CPAP in the treatment of patients with an apnea/hypopnea index (AHI) < or = 30/h.

METHODS

In a randomized crossover study, 16 men and 4 women (mean +/- SD age, 56.5 +/- 10.2 years; body mass index, 31.2 +/- 6.4; AHI, 17.5 +/- 7.7/h) were treated for 6 weeks with each modality.

RESULTS

In the initial phase, a significant improvement in AHI (baseline, 17.5 +/- 7.7/h; ISAD, 10.5 +/- 7.5/h [p < 0.05]; CPAP, 3.5 +/- 2.9/h [p < 0.01]) and in breathing-related arousals (baseline, 8.9 +/- 6.1/h; ISAD, 3.7 +/- 3.3/h [p < 0.01]; CPAP, 1.4 +/- 1.6/h [p < 0.01]) was achieved with both modalities. Considering all 20 subjects, after 6 weeks of treatment, normalization of the respiratory parameters was seen only with CPAP. However, 30% of the patients had a lasting reduction in AHI to < 10/h with the ISAD also. The patients considered the ISAD to be easier to use (scale of 1 to 6: ISAD, 1.8 +/- 1.1; CPAP, 3.1 +/- 1.5 [p < 0.05]), and indicated greater utilization of the device in comparison with CPAP.

CONCLUSION

Even in patients with mild-to-moderate OSAS, CPAP is the more effective long-term treatment modality. In the individual case, the better compliance seen with the ISAD may be advantageous.

Is adjustability advantageous in mandibular advancement appliances in the treatment of sleep-disordered breathing?

Mandibular advancement appliances (MAD) that can adjust the amount of mandibular protrusion in response to treatment results are becoming popular with dentists who treat sleep-disorder breathing. Clinicians commonly assume that they are more efficacious and more comfortable to wear than monoblock appliances. An adjustable MAD was compared with one that stabilized the mandible at 70% of the protrusive path. There was not a significant difference in their overall efficacy. The adjustable MAD appeared to be more effective in the more severe cases, presumably due to the greater mandibular advancement; the nonadjustable MAD appeared to be more effective in the less severe cases, presumably due to the greater mandibular stabilization. Existing research was examined and biomechanical principles were considered. Insufficient research exists to definitely evaluate the pros and cons of adjustability vs. stability. There does not appear to be sufficient evidence to support the assumption that adjustable MADs are more efficacious or more comfortable to wear than monoblock appliances.