Interacting effects of genioglossus stimulation and mandibular advancement in sleep apnea (original) (raw)
Related papers
Parameters affecting pharyngeal response to genioglossus stimulation in sleep apnoea
European Respiratory Journal, 2010
Chronic stimulation of the hypoglossus nerve may provide a new treatment modality for obstructive sleep apnoea (OSA). In previous studies we observed large differences in response to stimulation of the genioglossus (GG). We hypothesised that both individual patient characteristics and the area of the GG stimulated are responsible for these differences. In the present study, we compared the response to GG electrical stimulation at the anterior area (GGa-ES), which activates the whole GG and the posterior area (GGp-ES), which activates preferentially the longitudinal fibres. Studies were performed in 14 propofol-sedated OSA patients. The parameters evaluated included cephalometry, pressure-flow relationship and pharyngeal shape and compliance assessed by pharyngoscopy. Compared with GGa-ES, GGp-ES resulted in significantly larger decreases in the critical value of end-expiratory pressure (Pcrit) (from 3.8¡2.2 to 2.9¡3.3 and-2.0¡3.9 cmH 2 O, respectively (p,0.001)). Both tongue size and velopharyngeal shape (anteroposterior to lateral ratio) correlated significantly with the decrease in Pcrit during GGp-ES (R50.53 and-0.66, respectively; p,0.05). In the patients with the larger tongue size (n57), the decrease in Pcrit reached 8.0¡2.2 cmH 2 O during GGp-ES. We conclude that directing stimulation to longitudinal fibres of the GG improves the flowmechanical effect. In addition, patients with large tongues and narrow pharynx tend to respond better to GGp-ES.
Canadian respiratory journal : journal of the Canadian Thoracic Society
In some individuals with obstructive sleep apnea (OSA), oronasal continuous positive airway pressure (CPAP) leads to poorer OSA correction than nasal CPAP. The authors hypothesized that this results from posterior mandibular displacement caused by the oronasal mask. To test this hypothesis using a mandibular advancement device (MAD) for mandibular stabilization. Subjects whose OSA was not adequately corrected by oronasal CPAP at pressures for which nasal CPAP was effective were identified. These subjects underwent polysomnography (PSG) CPAP titration with each nasal and oronasal mask consecutively, with esophageal pressure and leak monitoring, to obtain the effective pressure (Peff) of CPAP for correcting obstructive events with each mask (maximum 20 cmH2O). PSG titration was repeated using a MAD in the neutral position. Cephalometry was performed. Six subjects with mean (± SD) nasal Peff 10.4±3.0 cmH2O were studied. Oronasal Peff was greater than nasal Peff in all subjects, with ob...
The effect of increased genioglossus activity and end-expiratory lung volume on pharyngeal collapse
Journal of Applied Physiology, 2010
Increasing either genioglossus muscle activity (GG) or end-expiratory lung volume (EELV) improves airway patency but not sufficiently for adequate treatment of obstructive sleep apnea (OSA) in most patients. The mechanisms by which these variables alter airway collapsibility likely differ, with increased GG causing airway dilation, whereas increased EELV may stiffen the airway walls through caudal traction. We sought to determine whether the airway stabilizing effect of GG activation is enhanced when EELV is increased. To investigate this aim, 15 continuous positive airway pressure (CPAP)-treated OSA patients were instrumented with an epiglottic catheter, intramuscular GG-EMG electrodes, magnetometers, and a nasal mask/pneumotachograph. Subjects slept supine in a sealed, head-out plastic chamber in which the extra-thoracic pressure could be lowered (to raise EELV) while on nasal CPAP with a variable deadspace to allow CO2 stimulation (and GG activation). The pharyngeal critical clos...
International Archives of Medicine, 2016
Background: The efficacy of mandibular advancement devices (MAD) in the treatment of obstructive sleep apnea (OSA) varies widely among patients, and at present it is difficult to predict success. Previous studies have shown a relationship between a gain in pharyngeal volume with MAD in situ and the success of the treatment. The aim of this study was to evaluate this change in volume of the upper airway using cone beam computed tomography (CBCT), measured at a baseline of maximum intercuspation (T0) and at maximum protrusion (T1) using a George Gauge to simulate a MAD produced protusion, and investigate whether this change in volume can be used to predict success with MAD. Methods and Findings: 10 individuals with mild/moderate OSA underwent CBCT at baseline (T0-maximum intercuspation) and time 1 (T1-maximum protrusion using a George Gauge for bite registration). All patients then underwent polysomnography before and after MAD treatment. The total volume, total area and minimal cross section area of the pharynx were then analyzed again by CBCT. The mean of the protrusive position using a George Gauge at baseline (12.2mm ± 1.9) was similar to the maximum comfortable position achieved with MAD (11.6mm ± 2.08). MAD treatment significantly reduced the Apnea Hypopnea Index (AHI) values (11.7 ± 6.7 to 2.4 ± 3.1) (p=0.01). The retropalatal volume increased significantly between T0 and T1 (6240mm² ± 2224 to 7720mm² ± 3516) (p=0.04). Changes in volume measured by CBCT (T1-T0) were positively predictive for changes in AHI (initial-final) (p = 0.05).
Journal of Oral and Maxillofacial Surgery, 2012
lntroduction: Airway size increases are associated with maxillomandibular advancement (MMA) surgery and improvement or elimination of obstructive sleep apnea (OSA). The 3-dimensional morphologic, volumetric, height, cross-sectional surface area, and diameter changes of the upper airway in patients with OSA after MMA, however, are not well understood. Methods: Patients with moderate or severe OSA who underwent MMA surgery were evaluated by preoperative and postoperative cone-beam computed tomography scans and polysomnograms. The upper airway space was also divided into retropalatal and retroglossal spaces and was analyzed for volumetric, height, cross-sectional surJace area, transverse, and anteroposterior diameter changes. Results: Ten consecutive OSA patients with an average preoperative apnea/hypopnea index of 46 and treated with MMA surgery were included in this study. There were 8 men and 2 women, with an average age of 46 years and an average body mass index of 28. There was an average of a 2.5Jold increase in the total volume of the upper airway space. The retropalatal space increased by 3.S-fold. The retroglossal space increased by 1.S{old. The greatest change in a cross-sectional area occurred in the transverse axis in both the retroglossal and retropalatal spaces. The average apnea/hypopnea index was 4 postoperatively. Conclusion:
European Journal of Dentistry, 2021
Objectives The purpose of this pilot study was to determine whether compliance to auto-adjusting positive airway pressure (APAP) improves with the addition of a mandibular advancement device (MAD). Secondary outcome measures included were APAP pressure, subjective daytime sleepiness, apnea–hypopnea index (AHI), and mask leaks. Setting and Sample Population Participants included were diagnosed with moderate-to-severe obstructive sleep apnea (OSA) and became noncompliant to prescribed APAP. Thirteen participants with a mean age of 61.6 years were recruited for this study. Materials and Methods All participants were given a MAD to use with their APAP. Parameters measured included APAP pressure, AHI, mask leak reported via ResMed AirViewTM software, and self-reported daytime sleepiness (Epworth Sleepiness Scale [ESS]). A paired two-sample for mean t-test was performed to determine significance. Results The mean difference of pre- and postintervention APAP compliance was 23.1%, which was...
Pharyngeal Pressure and Flow Effects on Genioglossus Activation in Normal Subjects
American Journal of Respiratory and Critical Care Medicine, 2002
Pharyngeal dilator muscles are clearly important in the pathogenesis of obstructive sleep apnea syndrome. Substantial data support the role of local mechanisms in mediating pharyngeal dilator muscle activation in normal humans during wakefulness. Using a recently reported iron lung ventilation model, we sought to determine the stimuli modulating genioglossus activity, dissociating the influences of pharyngeal negative pressure, from inspiratory airflow, resistance, and CO 2. To achieve this aim, we used two gas densities at several levels of end-tidal CO 2 and a number of intrapharyngeal negative pressures. The correlations between genioglossus electromyography (GGEMG) and epiglottic pressure across a breath remained robust under all conditions (R values range from 0.71 Ϯ 0.07 to 0.83 Ϯ 0.05). In addition, there was no significant change in the slope of this relationship despite variable gas density or CO 2 levels. Although flow also showed strong correlations with genioglossus activity, there was a significant change in the slope of the GGEMG/flow relationship with altered gas density. For the group averages across conditions (between breath analysis), the correlation with GGEMG was robust for negative pressure (R 2 ϭ 0.98) and less strong for other variables such as flow and resistance. These data suggest that independent of central pattern generator activity, intrapharyngeal negative pressure itself modulates genioglossus activity both within breaths and between breaths.
Life
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 ...
Journal of Applied Physiology, 2012
It is generally believed that reflex recruitment of pharyngeal dilator muscles is insufficient to open the airway of obstructive apnea (OSA) patients once it is closed and, therefore, that arousal is required. Yet arousal promotes recurrence of obstruction. There is no information about how much dilator [genioglossus (GG)] activation is required to open the airway (GG Opening Threshold) or about the capacity of reflex mechanisms to increase dilator activity before/without arousal (Non-Arousal Activation). The relationship between these two variables is important for ventilatory stability. We measured both variables in 32 OSA patients (apnea-hypopnea index 74 ± 42 events/h). GG activity was monitored while patients were on optimal continuous positive airway pressure (CPAP). Zopiclone was administered to delay arousal. Maximum GG activity (GGMAX) and airway closing pressure (PCRIT) were measured. During stable sleep CPAP was decreased to 1 cmH2O to induce obstructive events and the di...
American Journal of Orthodontics and Dentofacial Orthopedics, 1996
Knowledge of how dental appliances alter upper airway muscle activity when they are used for the treatment of snoring and/or obstructive sleep apnea (OSA) is very limited. The purpose of this study was to define the effect of a tongue retaining device (TRD) on awake genioglossus (GG) muscle activity in 10 adult subjects with OSA and in 6 age and body mass index (BMI) matched symptom-free control subjects. The TRD is a custom-made appliance designed to allow the tongue to remain in a forward position between the anterior teeth by holding the tongue in an anterior bulb with negative pressure, during sleep. This pulls the tongue forward to enlarge the volume of the upper airway and to reduce upper airway resistance. In this study, two customized TRDs were used for each subject. The TRD-A did not have an anterior bulb but incorporated lingual surface electrodes to record the GG electromyographic (EMG) activity. The TRD-B contained an anterior bulb and two similar electrodes. The GG EMG activity was also recorded while patients used the TRD-B but were instructed to keep their tongue at rest outside the anterior bulb; this condition is hereafter referred to as TRD-X. The GG EMG activity and nasal airflow were simultaneously recorded while subjects used these customized TRDs during spontaneous awake breathing in both the upright and supine position. The following results were obtained and were consistent whether subjects were in the upright or the supine position. The GG EMG activity was greater with the TRD-B than with the TRD-A in control subjects (p < 0.05), whereas the GG EMG activity was less with the TRD-B than with the TRD-A in subjects with OSA (p < 0.01). Furthermore, there was no significant difference between the GG EMG activity of the TRD-A and the TRD-X in control subjects, whereas there was less activity with the TRD-X than with the TRD-A in subjects with OSA (p < 0.05). On the basis of these findings, it was concluded that the TRD has different effects on the awake GG muscle activity in control subjects and patients with OSA. The resultant change in the anatomic configuration of the upper airway caused by the TRD may be important in the treatment of OSA because such a change may alleviate the impaired upper airway function. (Am J Orthod