Snoring and obstructive sleep apnoea (OSA) are worse or may only occur in the supine position. Th... more Snoring and obstructive sleep apnoea (OSA) are worse or may only occur in the supine position. The effect of body position on upper airway size has been reported, but the effect on tongue posture has not previously been examined. Detailed measurements were made of tongue posture from upright and supine lateral cephalograms on 24 men with OSA and 13 men with non-apnoeic snoring matched for age, body mass index, and craniofacial skeletal pattern. Patients with OSA had apnoea/hypopnoea indices (AHI) of > 50/hour and/or apnoea indices (AI) of > 25/hour while non-apnoeic snorers had AHI of < 10/hour and AI of < 5/hour. In non-apnoeic snorers the tongue depth measurements for the superior-posterior portion of the tongue were larger in the supine than in the upright position (p < 0.05). There was no significant difference in tongue depth measurements between the upright and the supine position in the patients with OSA. When awake patients with OSA move from the upright to th...
The purpose of this study was to define the changes in upper airway size in response to a body po... more The purpose of this study was to define the changes in upper airway size in response to a body position change from upright to supine. A total of 15 male Caucasian obstructive sleep apnea (OSA) patients with a mean apnea hypopnea index of 31.0 +/- 13.9/hr were recruited for this study. A set of upright and supine cephalograms was traced and digitized for each patient. The most constricted site in the upright position was located in the velopharynx. When the body position was changed from upright to supine, a significant reduction in the anteroposterior dimension was observed only at the level of the velopharynx (p < 0.05). Sagittal cross-sectional areas of the velopharynx and the oropharynx significantly decreased (p < 0.05), but the soft palate area increased (p < 0.05). We conclude that the velopharynx is not only the narrowest site in both upright and supine body positions but also the most changeable site in response to an alteration in body position during wakefulness....
Although uvulopalatopharyngoplasty relieves obstructive sleep apnea in the majority of patients, ... more Although uvulopalatopharyngoplasty relieves obstructive sleep apnea in the majority of patients, the factors that determine a successful response are not well defined. To determine whether preoperative awake upper airway measurements predict the response to uvulopalatopharyngoplasty, presurgical lateral cephalometric radiographs were evaluated on 60 consecutive patients with symptomatic obstructive sleep apnea. Patients underwent overnight polysomnograms before uvulopalatopharyngoplasty and 3 months afterwards. Forty-eight (80%) patients had a good response as defined by a postoperative apnea index of less than or equal to 4 apneas/hour or a reduction in apnea index of greater than or equal to 60%. Responders had a significantly narrower inferior airway space (P less than .0005) and a smaller ratio of inferior airway space to tongue length (P less than .001). Improvement in apnea severity following uvulopalatopharyngoplasty was related to the degree of airway narrowing (r = 0.36; P less than .01). This study shows that upper airway measurements help predict response to uvulopalatopharyngoplasty in patients with obstructive sleep apnea. Patients with a narrow airway, particularly relative to tongue size, have good responses to uvulopalatopharyngoplasty.
The objective of the study was to investigate the effects of oral appliance (OA) therapy on ambul... more 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 designed to assess the sensitivity and specificity of a portable sleep apnea recor... more This study was designed to assess the sensitivity and specificity of a portable sleep apnea recording device (ApneaLink) using standard polysomnography (PSG) as a reference and to evaluate the possibility of using the ApneaLink as a case selection technique for patients with suspected obstructive sleep apnea (OSA). Fifty patients (mean age 48.7 +/- 12.6 years, 32 males) were recruited during a 4-week period. A simultaneous recording of both the standard in-laboratory PSG and an ambulatory level 4 sleep monitor (ApneaLink) was performed during an overnight study for each patient. PSG sleep and respiratory events were scored manually according to standard criteria. ApneaLink data were analyzed either with the automated computerized algorithm provided by the manufacturer following the American Academy of Sleep Medicine standards (default setting DFAL) or The University of British Columbia Hospital sleep laboratory standards (alternative setting, ATAL). The ApneaLink respiratory disturbance indices (RDI), PSG apnea-hypopnea indices (AHI), and PSG oxygen desaturation index (ODI) were compared. The mean PSG-AHI was 30.0 +/- 25.8 events per hour. The means of DFAL-RDI and ATAL-RDI were 23.8 +/- 21.9 events per hour and 29.5 +/- 22.2 events per hour, respectively. Intraclass correlation coefficients were 0.958 between PSG-AHI and DFAL-RDI and 0.966 between PSG-AHI and ATAL-RDI. Receiver operator characteristic curves were constructed using a variety of PSG-AHI cutoff values (5, 10, 15, 20, and 30 events per hour). Optimal combinations of sensitivity and specificity for the various cutoffs were 97.7/66.7, 95.0/90.0, 87.5/88.9, 88.0/88.0, and 88.2/93.9, respectively for the default setting. The ApneaLink demonstrated the best agreement with laboratory PSG data at cutoffs of AHI &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or= 10. There were no significant differences among PSG-AHI, DFAL-RDI, and ATAL-RDI when all subjects were considered as one group. ODI at 2%, 3%, and 4% desaturation levels showed significant differences (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) compared with PSG-AHI, DFAL-RDI, and ATAL-RDI for the entire group. The ApneaLink is an ambulatory sleep monitor that can detect OSA and/or hypopnea with acceptable reliability. The screening and diagnostic capability needs to be verified by further evaluation and manual scoring of the ApneaLink. It could be a better choice than traditional oximetry in terms of recording respiratory events, although severity may be under- or overestimated.
Obstructive sleep apnea (OSA) is a common disease. Given the costs of in-laboratory polysomnograp... more Obstructive sleep apnea (OSA) is a common disease. Given the costs of in-laboratory polysomnography (PSG), alternative ambulatory methods for accurate diagnosis are desirable. The objective of this study was to evaluate the performance of a simple device (SleepCheck) to identify patients with sleep apnea. A total of 30 consecutive patients with suspected OSA syndrome referred to the sleep clinic were prospectively evaluated with standard PSG and SleepCheck simultaneously during an in-laboratory, supervised full-night diagnostic study. The PSG apnea and hypopnea index (AHI) was evaluated according to standard criteria, and SleepCheck assessed the respiratory disturbance index (RDI) based on nasal cannula pressure fluctuations. Compared to the full-night PSG, SleepCheck systematically overscored respiratory events (the mean difference between SleepCheck RDI and PSG AHI was 27.4+/-13.3 events per hour). This overscoring was in part related to normal physiologic decreases in flow during rapid eye movement sleep or after an arousal. However, there was reasonable correlation between AHI and RDI (r=0.805). Receiver operating characteristic curves with threshold values of AHI of 10 and 20/h demonstrated areas under the curves (AUCs) of 0.915 and 0.910, respectively. Optimum combinations of sensitivity and specificity for these thresholds were calculated as 86.4/75.0 and 88.9/81.0, respectively. Overall, the SleepCheck substantially overscored apneas and hypopneas in patients with suspected OSA. However, after correction of the bias, the SleepCheck had reasonable accuracy with an AUC, sensitivity, and specificity similar to other ambulatory type 4 devices currently available.
In a curved tube, the amount of airflow appears to be influenced by the amount of curvature. The ... more In a curved tube, the amount of airflow appears to be influenced by the amount of curvature. The purpose of this study was to investigate changes in obstructive sleep apnoea (OSA) severity and awake velopharyngeal curvature in response to an anteriorly titrated mandibular position in 20 male OSA patients. Baseline supine cephalometry was obtained before the initial insertion of a titratable oral appliance and follow-up supine cephalometry was undertaken after titration of the mandibular position with the appliance in place. The mean apnoea/hypopnea index (AHI) before treatment (31.6 +/- 13.0 events x h(-1)) was significantly reduced (9.8 +/- 7.4 events x h(-1)) after titration of the mandibular position in all 20 patients. There was a significant increase in the anteroposterior calibre and the radius of the curvature of the anterior wall of the velopharynx in 14 good responders who exhibited an AHI reduction to &lt; or = 15. Similar observations were not found in six poor responders. To conclude, an anteriorly titrated mandibular position reduced obstructive sleep apnoea severity, enlarged the velopharynx and diminished the curvature of the anterior velopharyngeal wall in good responders. It is proposed that this change in the upper airway curvature associated with mandibular advancement may effect obstructive sleep apnoea severity through its effect on airflow dynamics.
An 8-year-old girl with Hallermann-Streiff syndrome (oculomandibulofacial syndrome) was examined.... more An 8-year-old girl with Hallermann-Streiff syndrome (oculomandibulofacial syndrome) was examined. She had a history of severe snoring, reported nocturnal apnea, excessive daytime hypersomnolence, nocturnal enuresis, and failure to thrive. Overnight polysomnography confirmed severe obstructive sleep apnea. Long-term nasal continuous positive airway pressure (CPAP) therapy completely relieved the obstructive sleep apnea and was associated with improved weight gain and growth.
Vertical mandibular posture is thought to be related to narrowing of the upper airway, because mo... more Vertical mandibular posture is thought to be related to narrowing of the upper airway, because mouth opening is associated with an inferior-posterior movement of the mandible and the tongue which influences pharyngeal airway patency. To test whether the mandibular posture is related to the occurrence and/or termination of obstructive sleep apnoea (OSA), the vertical mandibular position was recorded intraorally using a magnet sensor during a standard sleep study in seven patients with OSA. Measurements were recorded during sleep both in the supine and lateral recumbent positions. The percentage of total sleep time spent with mandibular opening greater than 5 mm was significantly larger (p&lt;0.001) in patients with OSA (69.3+/-23.3%) compared with our previous results obtained from healthy adults without OSA (11.1+/-11.6%). The stage of sleep affected the vertical mandibular posture during sleep in the supine position, but not in the lateral recumbent position in patients with OSA. In non-rapid eye-movement sleep, mandibular opening increased progressively during apnoeic episodes and decreased at the termination of apnoeic episodes. In contrast, no significant change in mandibular posture occurred in apnoeic episodes during rapid eye-movement sleep. It was concluded that the vertical mandibular posture is more open during sleep in patients with OSA than in healthy adults and that mandibular opening increases progressively during apnoeic episodes and decreases at the termination of those episodes.
To test the hypothesis that long-term use of an oral appliance (OA) does not cause changes in the... more To test the hypothesis that long-term use of an oral appliance (OA) does not cause changes in the occlusal contact area (OCA). Baseline and follow-up treatment study models were obtained for 45 patients with obstructive sleep apnea who had been using an OA for 4 or more days/week for more than 5 years. Study models in centric occlusion, with an inserted pressure-sensitive sheet, were loaded in compression. An image scanner was used to evaluate OCA. A significant change in total OCA was identified in 39 patients (86.7%): a decrease in 26 (66.7%) and an increase in 13 (33.3%) patients. Regional changes &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;5% were observed in &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;90% of patients in each of the three regions. In the molar and premolar regions, 24 (53.3%) and 27 (60.0%) of the patients showed an OCA decrease, while only 16 (35.6%) and 15 (33.3%) showed an increase. Conversely, for the anterior region, more increases (24 patients-53.3%) than decreases were identified. The hypothesis is rejected. Long-term OA therapy resulted in dramatic changes of occlusion, suggesting that monitoring of occlusal changes is required.
American Journal of Orthodontics and Dentofacial Orthopedics, 2001
The purpose of this study was to investigate whether any physiologic or cephalometric parameters ... more The purpose of this study was to investigate whether any physiologic or cephalometric parameters could be used to predict the efficacy of an adjustable mandibular advancement appliance for treating obstructive sleep apnea (OSA). Forty-two male and 5 female patients with OSA were recruited on the basis of baseline polysomnography with a documented Apnea and Hypopnea Index (AHI) greater than 15 per hour. Repeat polysomnography was performed with the appliance in place. Baseline cephalometry was performed for each patient, and follow-up cephalometry was completed for 19 of the subjects. The subjects were divided into 3 groups on the basis of the degree of change in the AHI with oral appliance therapy: good response (&gt; 75% decrease in AHI), moderate response (25% to 75% decrease in AHI), and poor response (&lt; 25% decrease in AHI). Patients with a good response were younger and had smaller upper airways. In a linear regression analysis, the change in AHI (%) was associated with physiologic (age and body mass index), cephalometric (overjet, height of the maxillary molars, vertical height of the hyoid bone), and airway variables. However, changes in either overbite or overjet were not related to changes in any of the polysomnographic variables for the 19 subjects. A stepwise regression analysis revealed a better treatment response with the adjustable mandibular advancement appliance in patients who were younger and had a lower body mass index, a longer maxilla, a smaller oropharynx, a smaller overjet, less erupted maxillary molars, and a larger ratio of vertical airway length to the cross-sectional area of the soft palate.
American Journal of Orthodontics and Dentofacial Orthopedics, 2000
The purpose of this study was to investigate the effects of a mandibular repositioner on airway, ... more The purpose of this study was to investigate the effects of a mandibular repositioner on airway, sleep, and respiratory variables in patients with obstructive sleep apnea. Twenty-two patients selected for this study were confirmed with a diagnosis of obstructive sleep apnea based on initial nocturnal polysomnography. The patients were fitted with a mandibular repositioner designed to hold the mandible anteroinferiorly. Six months later, an outcome polysomnographic study was undertaken for each patient with the appliance in place. Lateral cephalometric radiographs in the upright position were also obtained before and after 6 months of treatment. The respiratory disturbance index decreased in 21 of the 22 patients with the appliance in place. The mean respiratory disturbance index of the 22 patients decreased significantly from 40.3 to 11.7 events per hour (P &lt;.01). Some 59.1% of subjects were considered a treatment success with follow-up respiratory disturbance index &lt; 10 events per hour. The mean minimum blood oxygen saturation level during sleep also improved significantly from 73.4% to 81.3% (P &lt;. 01). The mandibular repositioner was constructed to position the mandible at 75% of the maximal mandibular advancement and with a 7 mm opening between the upper and lower incisors, and no aberrant effect on temporomandibular joint was noted. The retropalatal airway space increased and the cross-sectional area of the soft palate and the vertical distance of the hyoid bone to the mandibular plane decreased significantly. The tongue posture became significantly flatter. A significant linear correlation was found between the reduction in apnea index and specific craniofacial skeletal structures (length of anterior cranial base, mandibular plane angle, and upper to lower facial height ratios, P &lt;.05). Subjects with a smaller reduction in apnea index tended to have shorter anterior cranial bases, steeper mandibular planes, and smaller upper to lower facial height ratios. We conclude that a mandibular repositioner may be an effective treatment alternative for obstructive sleep apnea and that a reduction in the frequency of apneic episodes is mainly attributed to the effects of the appliance on oropharyngeal structures.
Snoring and obstructive sleep apnoea (OSA) are worse or may only occur in the supine position. Th... more Snoring and obstructive sleep apnoea (OSA) are worse or may only occur in the supine position. The effect of body position on upper airway size has been reported, but the effect on tongue posture has not previously been examined. Detailed measurements were made of tongue posture from upright and supine lateral cephalograms on 24 men with OSA and 13 men with non-apnoeic snoring matched for age, body mass index, and craniofacial skeletal pattern. Patients with OSA had apnoea/hypopnoea indices (AHI) of > 50/hour and/or apnoea indices (AI) of > 25/hour while non-apnoeic snorers had AHI of < 10/hour and AI of < 5/hour. In non-apnoeic snorers the tongue depth measurements for the superior-posterior portion of the tongue were larger in the supine than in the upright position (p < 0.05). There was no significant difference in tongue depth measurements between the upright and the supine position in the patients with OSA. When awake patients with OSA move from the upright to th...
The purpose of this study was to define the changes in upper airway size in response to a body po... more The purpose of this study was to define the changes in upper airway size in response to a body position change from upright to supine. A total of 15 male Caucasian obstructive sleep apnea (OSA) patients with a mean apnea hypopnea index of 31.0 +/- 13.9/hr were recruited for this study. A set of upright and supine cephalograms was traced and digitized for each patient. The most constricted site in the upright position was located in the velopharynx. When the body position was changed from upright to supine, a significant reduction in the anteroposterior dimension was observed only at the level of the velopharynx (p < 0.05). Sagittal cross-sectional areas of the velopharynx and the oropharynx significantly decreased (p < 0.05), but the soft palate area increased (p < 0.05). We conclude that the velopharynx is not only the narrowest site in both upright and supine body positions but also the most changeable site in response to an alteration in body position during wakefulness....
Although uvulopalatopharyngoplasty relieves obstructive sleep apnea in the majority of patients, ... more Although uvulopalatopharyngoplasty relieves obstructive sleep apnea in the majority of patients, the factors that determine a successful response are not well defined. To determine whether preoperative awake upper airway measurements predict the response to uvulopalatopharyngoplasty, presurgical lateral cephalometric radiographs were evaluated on 60 consecutive patients with symptomatic obstructive sleep apnea. Patients underwent overnight polysomnograms before uvulopalatopharyngoplasty and 3 months afterwards. Forty-eight (80%) patients had a good response as defined by a postoperative apnea index of less than or equal to 4 apneas/hour or a reduction in apnea index of greater than or equal to 60%. Responders had a significantly narrower inferior airway space (P less than .0005) and a smaller ratio of inferior airway space to tongue length (P less than .001). Improvement in apnea severity following uvulopalatopharyngoplasty was related to the degree of airway narrowing (r = 0.36; P less than .01). This study shows that upper airway measurements help predict response to uvulopalatopharyngoplasty in patients with obstructive sleep apnea. Patients with a narrow airway, particularly relative to tongue size, have good responses to uvulopalatopharyngoplasty.
The objective of the study was to investigate the effects of oral appliance (OA) therapy on ambul... more 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 designed to assess the sensitivity and specificity of a portable sleep apnea recor... more This study was designed to assess the sensitivity and specificity of a portable sleep apnea recording device (ApneaLink) using standard polysomnography (PSG) as a reference and to evaluate the possibility of using the ApneaLink as a case selection technique for patients with suspected obstructive sleep apnea (OSA). Fifty patients (mean age 48.7 +/- 12.6 years, 32 males) were recruited during a 4-week period. A simultaneous recording of both the standard in-laboratory PSG and an ambulatory level 4 sleep monitor (ApneaLink) was performed during an overnight study for each patient. PSG sleep and respiratory events were scored manually according to standard criteria. ApneaLink data were analyzed either with the automated computerized algorithm provided by the manufacturer following the American Academy of Sleep Medicine standards (default setting DFAL) or The University of British Columbia Hospital sleep laboratory standards (alternative setting, ATAL). The ApneaLink respiratory disturbance indices (RDI), PSG apnea-hypopnea indices (AHI), and PSG oxygen desaturation index (ODI) were compared. The mean PSG-AHI was 30.0 +/- 25.8 events per hour. The means of DFAL-RDI and ATAL-RDI were 23.8 +/- 21.9 events per hour and 29.5 +/- 22.2 events per hour, respectively. Intraclass correlation coefficients were 0.958 between PSG-AHI and DFAL-RDI and 0.966 between PSG-AHI and ATAL-RDI. Receiver operator characteristic curves were constructed using a variety of PSG-AHI cutoff values (5, 10, 15, 20, and 30 events per hour). Optimal combinations of sensitivity and specificity for the various cutoffs were 97.7/66.7, 95.0/90.0, 87.5/88.9, 88.0/88.0, and 88.2/93.9, respectively for the default setting. The ApneaLink demonstrated the best agreement with laboratory PSG data at cutoffs of AHI &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or= 10. There were no significant differences among PSG-AHI, DFAL-RDI, and ATAL-RDI when all subjects were considered as one group. ODI at 2%, 3%, and 4% desaturation levels showed significant differences (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) compared with PSG-AHI, DFAL-RDI, and ATAL-RDI for the entire group. The ApneaLink is an ambulatory sleep monitor that can detect OSA and/or hypopnea with acceptable reliability. The screening and diagnostic capability needs to be verified by further evaluation and manual scoring of the ApneaLink. It could be a better choice than traditional oximetry in terms of recording respiratory events, although severity may be under- or overestimated.
Obstructive sleep apnea (OSA) is a common disease. Given the costs of in-laboratory polysomnograp... more Obstructive sleep apnea (OSA) is a common disease. Given the costs of in-laboratory polysomnography (PSG), alternative ambulatory methods for accurate diagnosis are desirable. The objective of this study was to evaluate the performance of a simple device (SleepCheck) to identify patients with sleep apnea. A total of 30 consecutive patients with suspected OSA syndrome referred to the sleep clinic were prospectively evaluated with standard PSG and SleepCheck simultaneously during an in-laboratory, supervised full-night diagnostic study. The PSG apnea and hypopnea index (AHI) was evaluated according to standard criteria, and SleepCheck assessed the respiratory disturbance index (RDI) based on nasal cannula pressure fluctuations. Compared to the full-night PSG, SleepCheck systematically overscored respiratory events (the mean difference between SleepCheck RDI and PSG AHI was 27.4+/-13.3 events per hour). This overscoring was in part related to normal physiologic decreases in flow during rapid eye movement sleep or after an arousal. However, there was reasonable correlation between AHI and RDI (r=0.805). Receiver operating characteristic curves with threshold values of AHI of 10 and 20/h demonstrated areas under the curves (AUCs) of 0.915 and 0.910, respectively. Optimum combinations of sensitivity and specificity for these thresholds were calculated as 86.4/75.0 and 88.9/81.0, respectively. Overall, the SleepCheck substantially overscored apneas and hypopneas in patients with suspected OSA. However, after correction of the bias, the SleepCheck had reasonable accuracy with an AUC, sensitivity, and specificity similar to other ambulatory type 4 devices currently available.
In a curved tube, the amount of airflow appears to be influenced by the amount of curvature. The ... more In a curved tube, the amount of airflow appears to be influenced by the amount of curvature. The purpose of this study was to investigate changes in obstructive sleep apnoea (OSA) severity and awake velopharyngeal curvature in response to an anteriorly titrated mandibular position in 20 male OSA patients. Baseline supine cephalometry was obtained before the initial insertion of a titratable oral appliance and follow-up supine cephalometry was undertaken after titration of the mandibular position with the appliance in place. The mean apnoea/hypopnea index (AHI) before treatment (31.6 +/- 13.0 events x h(-1)) was significantly reduced (9.8 +/- 7.4 events x h(-1)) after titration of the mandibular position in all 20 patients. There was a significant increase in the anteroposterior calibre and the radius of the curvature of the anterior wall of the velopharynx in 14 good responders who exhibited an AHI reduction to &lt; or = 15. Similar observations were not found in six poor responders. To conclude, an anteriorly titrated mandibular position reduced obstructive sleep apnoea severity, enlarged the velopharynx and diminished the curvature of the anterior velopharyngeal wall in good responders. It is proposed that this change in the upper airway curvature associated with mandibular advancement may effect obstructive sleep apnoea severity through its effect on airflow dynamics.
An 8-year-old girl with Hallermann-Streiff syndrome (oculomandibulofacial syndrome) was examined.... more An 8-year-old girl with Hallermann-Streiff syndrome (oculomandibulofacial syndrome) was examined. She had a history of severe snoring, reported nocturnal apnea, excessive daytime hypersomnolence, nocturnal enuresis, and failure to thrive. Overnight polysomnography confirmed severe obstructive sleep apnea. Long-term nasal continuous positive airway pressure (CPAP) therapy completely relieved the obstructive sleep apnea and was associated with improved weight gain and growth.
Vertical mandibular posture is thought to be related to narrowing of the upper airway, because mo... more Vertical mandibular posture is thought to be related to narrowing of the upper airway, because mouth opening is associated with an inferior-posterior movement of the mandible and the tongue which influences pharyngeal airway patency. To test whether the mandibular posture is related to the occurrence and/or termination of obstructive sleep apnoea (OSA), the vertical mandibular position was recorded intraorally using a magnet sensor during a standard sleep study in seven patients with OSA. Measurements were recorded during sleep both in the supine and lateral recumbent positions. The percentage of total sleep time spent with mandibular opening greater than 5 mm was significantly larger (p&lt;0.001) in patients with OSA (69.3+/-23.3%) compared with our previous results obtained from healthy adults without OSA (11.1+/-11.6%). The stage of sleep affected the vertical mandibular posture during sleep in the supine position, but not in the lateral recumbent position in patients with OSA. In non-rapid eye-movement sleep, mandibular opening increased progressively during apnoeic episodes and decreased at the termination of apnoeic episodes. In contrast, no significant change in mandibular posture occurred in apnoeic episodes during rapid eye-movement sleep. It was concluded that the vertical mandibular posture is more open during sleep in patients with OSA than in healthy adults and that mandibular opening increases progressively during apnoeic episodes and decreases at the termination of those episodes.
To test the hypothesis that long-term use of an oral appliance (OA) does not cause changes in the... more To test the hypothesis that long-term use of an oral appliance (OA) does not cause changes in the occlusal contact area (OCA). Baseline and follow-up treatment study models were obtained for 45 patients with obstructive sleep apnea who had been using an OA for 4 or more days/week for more than 5 years. Study models in centric occlusion, with an inserted pressure-sensitive sheet, were loaded in compression. An image scanner was used to evaluate OCA. A significant change in total OCA was identified in 39 patients (86.7%): a decrease in 26 (66.7%) and an increase in 13 (33.3%) patients. Regional changes &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;5% were observed in &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;90% of patients in each of the three regions. In the molar and premolar regions, 24 (53.3%) and 27 (60.0%) of the patients showed an OCA decrease, while only 16 (35.6%) and 15 (33.3%) showed an increase. Conversely, for the anterior region, more increases (24 patients-53.3%) than decreases were identified. The hypothesis is rejected. Long-term OA therapy resulted in dramatic changes of occlusion, suggesting that monitoring of occlusal changes is required.
American Journal of Orthodontics and Dentofacial Orthopedics, 2001
The purpose of this study was to investigate whether any physiologic or cephalometric parameters ... more The purpose of this study was to investigate whether any physiologic or cephalometric parameters could be used to predict the efficacy of an adjustable mandibular advancement appliance for treating obstructive sleep apnea (OSA). Forty-two male and 5 female patients with OSA were recruited on the basis of baseline polysomnography with a documented Apnea and Hypopnea Index (AHI) greater than 15 per hour. Repeat polysomnography was performed with the appliance in place. Baseline cephalometry was performed for each patient, and follow-up cephalometry was completed for 19 of the subjects. The subjects were divided into 3 groups on the basis of the degree of change in the AHI with oral appliance therapy: good response (&gt; 75% decrease in AHI), moderate response (25% to 75% decrease in AHI), and poor response (&lt; 25% decrease in AHI). Patients with a good response were younger and had smaller upper airways. In a linear regression analysis, the change in AHI (%) was associated with physiologic (age and body mass index), cephalometric (overjet, height of the maxillary molars, vertical height of the hyoid bone), and airway variables. However, changes in either overbite or overjet were not related to changes in any of the polysomnographic variables for the 19 subjects. A stepwise regression analysis revealed a better treatment response with the adjustable mandibular advancement appliance in patients who were younger and had a lower body mass index, a longer maxilla, a smaller oropharynx, a smaller overjet, less erupted maxillary molars, and a larger ratio of vertical airway length to the cross-sectional area of the soft palate.
American Journal of Orthodontics and Dentofacial Orthopedics, 2000
The purpose of this study was to investigate the effects of a mandibular repositioner on airway, ... more The purpose of this study was to investigate the effects of a mandibular repositioner on airway, sleep, and respiratory variables in patients with obstructive sleep apnea. Twenty-two patients selected for this study were confirmed with a diagnosis of obstructive sleep apnea based on initial nocturnal polysomnography. The patients were fitted with a mandibular repositioner designed to hold the mandible anteroinferiorly. Six months later, an outcome polysomnographic study was undertaken for each patient with the appliance in place. Lateral cephalometric radiographs in the upright position were also obtained before and after 6 months of treatment. The respiratory disturbance index decreased in 21 of the 22 patients with the appliance in place. The mean respiratory disturbance index of the 22 patients decreased significantly from 40.3 to 11.7 events per hour (P &lt;.01). Some 59.1% of subjects were considered a treatment success with follow-up respiratory disturbance index &lt; 10 events per hour. The mean minimum blood oxygen saturation level during sleep also improved significantly from 73.4% to 81.3% (P &lt;. 01). The mandibular repositioner was constructed to position the mandible at 75% of the maximal mandibular advancement and with a 7 mm opening between the upper and lower incisors, and no aberrant effect on temporomandibular joint was noted. The retropalatal airway space increased and the cross-sectional area of the soft palate and the vertical distance of the hyoid bone to the mandibular plane decreased significantly. The tongue posture became significantly flatter. A significant linear correlation was found between the reduction in apnea index and specific craniofacial skeletal structures (length of anterior cranial base, mandibular plane angle, and upper to lower facial height ratios, P &lt;.05). Subjects with a smaller reduction in apnea index tended to have shorter anterior cranial bases, steeper mandibular planes, and smaller upper to lower facial height ratios. We conclude that a mandibular repositioner may be an effective treatment alternative for obstructive sleep apnea and that a reduction in the frequency of apneic episodes is mainly attributed to the effects of the appliance on oropharyngeal structures.
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