Why most patients do not exhibit obstructive sleep apnea after mandibular setback surgery?
ABSTRACT: Maxillomandibular advancement (MMA) is effective for the treatment of obstructive sleep apnea (OSA). In previous studies, the airway was increased in the anteroposterior and transverse dimensions after MMA. However, the effect of the opposite of mandibular movement (mandibular setback) on the airway is still controversial. Mandibular setback surgery has been suggested to be one of the risk factors in the development of sleep apnea. Previous studies have found that mandibular setback surgery could reduce the total airway volume and posterior airway space significantly in both the one-jaw and two-jaw surgery groups. However, a direct cause-and-effect relationship between the mandibular setback and development of sleep apnea has not been clearly established. Moreover, there are only a few reported cases of postoperative OSA development after mandibular setback surgery. These findings may be attributed to a fundamental difference in demographic variables such as age, sex, and body mass index (BMI) between patients with mandibular prognathism and patients with OSA. Another possibility is that the site of obstruction or pattern of obstruction may be different between the awake and sleep status in patients with OSA and mandibular prognathism. In a case-controlled study, information including the BMI and other presurgical conditions potentially related to OSA should be considered when evaluating the airway. In conclusion, the preoperative evaluation and management of co-morbid conditions would be essential for the prevention of OSA after mandibular setback surgery despite its low incidence.
Project description:Mandibular setback osteotomies potentially lead to narrowing of the pharyngeal airways, subsequently resulting in post-surgical obstructive sleep apnea (OSA).To summarize current evidence from systematic reviews that has evaluated pharyngeal airway changes after mandibular setback with or without concomitant upper jaw osteotomies.PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched with no restriction of language or date. Systematic reviews studying changes in pharyngeal airway dimensions and respiratory parameters after mandibular setback with or without concomitant upper jaw osteotomies have been identified, screened for eligibility, included and analyzed in this study.Six systematic reviews have been included. While isolated mandibular setback osteotomies result in reduced oropharyngeal airway dimensions, the reduction is lesser in cases with concomitant upper jaw osteotomies. Only scarce evidence exists currently to what happens to naso- and hypo-pharyngeal airways. There is no evidence for post-surgical OSA, even though some studies reported reduced respiratory parameters after single-jaw mandibular setback with or without concomitant upper jaw osteotomies.Although mandibular setback osteotomies reduce pharyngeal airway dimensions, evidence confirming post-surgical OSA was not found. Nevertheless, potential post-surgical OSA should be taken into serious consideration during the treatment planning of particular orthognathic cases. As moderate evidence exists that double-jaw surgeries lead to less compromised post-surgical pharyngeal airways, they should be considered as the method of choice especially in cases with severe dentoskeletal Class III deformity.PROSPERO (registration number: CRD42016046484).
Project description:Mandibular advancement surgery may positively affect pharyngeal airways and therefore potentially beneficial to obstructive sleep apnea (OSA).To collect evidence from published systematic reviews that have evaluated pharyngeal airway changes related to mandibular advancement with or without maxillary procedures.PubMed, EMBASE, Web of Science, and Cochrane Library were searched without limiting language or timeline. Eligible systematic reviews evaluating changes in pharyngeal airway dimensions and respiratory parameters after mandibular advancement with or without maxillary surgery were identified and included.This overview has included eleven systematic reviews. Maxillomandibular advancement (MMA) increases linear, cross-sectional plane and volumetric measurements of pharyngeal airways significantly (p<0.0001), while reducing the apnea-hypopnea index (AHI) and the respiratory disturbance index (RDI) significantly (p<0.0001). Two systematic reviews included primary studies that have evaluated single-jaw mandibular advancement, but did not discuss their effect onto pharyngeal airways. Based on the included primary studies of those systematic reviews, single-jaw mandibular advancement was reported to significantly increase pharyngeal airway dimensions (p<0.05); however, conclusive long-term results were lacking.MMA increases pharyngeal airway dimensions and is beneficial to patients suffering from OSA. However, more evidence is still needed to draw definite conclusion related to the effect of single-jaw mandibular advancement osteotomies on pharyngeal airways.
Project description:BACKGROUND:Difficult airway management and obstructive sleep apnea may contribute to increased risk of perioperative morbidity and mortality. The objective of this systematic review and meta-analysis (SRMA) is to evaluate the evidence of a difficult airway being associated with obstructive sleep apnea (OSA) patients undergoing surgery. METHODS:The standard databases were searched from 1946 to April 2017 to identify the eligible articles. The studies which included adult surgical patients with either suspected or diagnosed obstructive sleep apnea must report at least one difficult airway event [either difficult intubation (DI), difficult mask ventilation (DMV), failed supraglottic airway insertion or difficult surgical airway] in sleep apnea and non-sleep apnea patients were included. RESULTS:Overall, DI was 3.46-fold higher in the sleep apnea vs non-sleep apnea patients (OSA vs. non-OSA: 13.5% vs 2.5%; OR 3.46; 95% CI: 2.32-5.16, p <0.00001). DMV was 3.39-fold higher in the sleep apnea vs non-sleep apnea patients (OSA vs. non-OSA: 4.4% vs 1.1%; OR 3.39; 95% CI: 2.74-4.18, p <0.00001). Combined DI and DMV was 4.12-fold higher in the OSA vs. non-OSA patients (OSA vs. non-OSA: 1.1% vs 0.3%; OR 4.12; 95% CI: 2.93-5.79, p <0.00001). There was no significant difference in the supraglottic airway failure rates in the sleep apnea vs non-sleep apnea patients (OR: 1.34; 95% CI: 0.70-2.59; p = 0.38). Meta-regression to adjust for various subgroups and baseline confounding factors did not impact the final inference of our results. CONCLUSION:This SRMA found that patients with obstructive sleep apnea had a three to four-fold higher risk of difficult intubation or mask ventilation or both, when compared to non-sleep apnea patients.
Project description:STUDY OBJECTIVES:Controversy exists as to whether elevated loop gain is a cause or consequence of obstructive sleep apnea (OSA). Upper airway surgery is commonly performed in Asian patients with OSA who have failed positive airway pressure therapy and who are thought to have anatomical predisposition to OSA. We hypothesized that high loop gain would decrease following surgical treatment of OSA due to reduced sleep apnea severity. METHODS:Polysomnography was performed preoperatively and postoperatively to assess OSA severity in 30 Chinese participants who underwent upper airway surgery. Loop gain was calculated using a validated clinically-applicable method by fitting a feedback control model to airflow. RESULTS:Patients were followed up for a median (interquartile range) of 130 (62, 224) days after surgery. Apnea-hypopnea index (AHI) changed from 60.8 (33.7, 71.7) to 18.4 (9.9, 42.5) events/h (P < .001). Preoperative and postoperative loop gain was 0.70 (0.58, 0.80) and 0.53 (0.46, 0.63) respectively (P < .001). There was a positive association between the decrease in loop gain and the improvement of AHI (P = .025). CONCLUSIONS:High loop gain was reduced by surgical treatment of OSA in our cohort. These data suggest that elevated loop gain may be acquired in OSA and may provide mechanistic insight into improvement in OSA with upper airway surgery. CLINICAL TRIAL REGISTRATION:Registry: ClinicalTrials.gov, Title: The Impact of Sleep Apnea Treatment on Physiology Traits in Chinese Patients With Obstructive Sleep Apnea, Identifier: NCT02696629, URL: https://clinicaltrials.gov/show/NCT02696629.
Project description:<label>ABSTRACT</label>A 55-year-old woman who presented to the sleep clinic with severe sleep apnea (OSA) (apnea-hypopnea index [AHI] 62) and excessive somnolence (Epworth Sleepiness Scale score 18/24), was imaged with MRI using the Spatial Modulation of Magnetization tagging sequence awake and asleep to visualize upper airway tissue movement. Awake quiet breathing resulted in minimal movement of upper airway tissues. Asleep sequences taken during airway opening post-apnea demonstrated neck extension, mandibular advancement, and widespread tongue deformation accompanying contraction of genioglossus. At the end of the asleep image sequence, the nasopharyngeal airway had a cross-sectional area larger than during quiet breathing awake and there was antero-lateral movement in the lateral walls. In conclusion, the airway responds to apnea by widespread contraction of the genioglossus, followed by mandibular advancement and neck extension. All these maneuvers stabilize and open the airway.
Project description:In recent years, bimaxillary rotation advancement (BRA) has become the method of choice for surgical treatment of obstructive sleep apnea (OSA). As dislocation of the jaw bones affects both, airways and facial contours, surgeons are facing the challenge of finding an optimal jaw position that allows for the reestablishment of normal airway ventilation and esthetic surgical outcome. Owing to the complexity of the facial anatomy and its mechanical behavior, individual planning of surgical OSA treatment under consideration of functional and esthetic aspects presents a challenge that surgeons typically approach in a non-quantitative manner using subjective evaluation and clinical experience. This paper describes a framework for individual planning of OSA treatment using bimaxillary rotation advancement, which relies on computational modeling of hard and soft tissue mechanics. The described framework for simulation of functional and esthetic post-surgery outcome was used in 10 OSA patients. Comparison of the simulation results with post-surgery data reveals that biomechanical simulation provides a reliable estimate for post-surgery facial tissue behavior and antero-posterior airway extension, but fails to accurately describe a surprisingly large lateral stretch of the velopharyngeal region. This discrepancy is traced back to anisotropic effects of pharyngeal muscles. Possible approaches to improving the accuracy of model predictions and defining sharp criteria for optimizing combined OSA planning are discussed.
Project description:(1) To determine whether facial phenotype, measured by quantitative photography, relates to underlying craniofacial obstructive sleep apnea (OSA) risk factors, measured with magnetic resonance imaging (MRI); (2) To assess whether these associations are independent of body size and obesity.Cross-sectional cohort.Landspitali, The National University Hospital, Iceland.One hundred forty patients (87.1% male) from the Icelandic Sleep Apnea Cohort who had both calibrated frontal and profile craniofacial photographs and upper airway MRI. Mean ± standard deviation age 56.1 ± 10.4 y, body mass index 33.5 ± 5.05 kg/m(2), with on-average severe OSA (apnea-hypopnea index 45.4 ± 19.7 h(-1)).N/A.Relationships between surface facial dimensions (photos) and facial bony dimensions and upper airway soft-tissue volumes (MRI) was assessed using canonical correlation analysis. Photo and MRI craniofacial datasets related in four significant canonical correlations, primarily driven by measurements of (1) maxillary-mandibular relationship (r = 0.8, P < 0.0001), (2) lower face height (r = 0.76, P < 0.0001), (3) mandibular length (r = 0.67, P < 0.0001), and (4) tongue volume (r = 0.52, P = 0.01). Correlations 1, 2, and 3 were unchanged when controlled for weight and neck and waist circumference. However, tongue volume was no longer significant, suggesting facial dimensions relate to tongue volume as a result of obesity.Significant associations were found between craniofacial variable sets from facial photography and MRI. This study confirms that facial photographic phenotype reflects underlying aspects of craniofacial skeletal abnormalities associated with OSA. Therefore, facial photographic phenotyping may be a useful tool to assess intermediate phenotypes for OSA, particularly in large-scale studies.
Project description:The aim of this study was to identify correlations between sleep apnea severity and tongue volume or posterior airway space measured via three-dimensional reconstruction of volumetric computerized tomography (CT) images in patients with obstructive sleep apnea (OSA) for use in predicting OSA severity and in surgical treatment. We also assessed associations between tongue volume and Mallampati score.Snoring/OSA male patients (n = 64) who underwent polysomnography, cephalometry, and CT scans were enrolled in this retrospective study. OSA was diagnosed when the apnea-hypopnea index (AHI) was greater than 5 (mild 5-14; moderate 15-29; severe>30). The patients were also categorized into the normal-mild group (n = 22) and the moderate-severe group (n = 42). Using volumetric CT images with the three-dimensional reconstruction technique, the volume of the tongue, posterior airway space volume, and intra-mandibular space were measured. The volumes, polysomnographic parameters, and physical examination findings were compared, and independent factors that are related to OSA were analysed.No associations between tongue volume or posterior airway space and the AHI were observed. However, multivariate linear analyses showed that tongue volume had significantly negative association with lowest O2 saturation (r = 0.365, p = 0.027). High BMI was related to an increase in tongue volume. Modified Mallampati scores showed borderline significant positive correlations with absolute tongue volume (r = 0.251, p = 0.046) and standardized tongue volume (absolute tongue volume / intramandibular area; r = 0.266, p = 0.034). Between the normal-mild and moderate-severe groups, absolute tongue volumes were not different, although the standardized tongue volume in the moderate-severe group was significantly higher.Absolute tongue volume showed stronger associations with lowest O2 saturation during sleep than with the severity of AHI. We also found that high BMI was a relevant factor for an increase in absolute tongue volume and modified Mallampati grading was a useful physical examination to predict tongue size.
Project description:Obstructive sleep apnea (OSA) is a common disease in adults, which influences human relations, quality of life and associates with major complications. Continuous positive airway pressure (CPAP) is the gold standard treatment modality in OSA patients. For patients incompliant or unwilling to CPAP therapy, surgery is an alternative treatment. Sleep surgery for OSA include intrapharyngeal surgery, extrapharyngeal surgery and bariatric surgery addressing upper airway soft tissue, maxillofacial bone, and obesity, respectively. Among sleep surgeries, intrapharyngeal surgery (soft tissue surgery) is widespread used and serves overwhelming majority in OSA surgical patients. Despite the popularity of intrapharyngeal surgery, its outcomes can be influenced by multiple factors and consequently need conjunctive remedy to enhance at the short-term and sustain in the long-term. In this article, we introduce updated indications for treating OSA, practical principle in decision-making between CPAP and surgery, hybrid procedures in treating obstruction at the nose, palate, tongue and epiglottis, and postoperative integrated treatment including oropharyngeal myofunctional therapy (local), positional therapy (regional), and body weight reduction (systemic), and circadian rhythm (central). In summary, intrapharyngeal surgery is a target-oriented procedure that needs to be performed precisely and combines with integrated treatment as a holistic care for OSA patients.
Project description:STUDY OBJECTIVES:The presence of obstructive sleep apnea (OSA) in ambulatory surgical patients causes significant perioperative concern; however, few data exist to guide clinicians' management decisions. The objective of this study was to measure changes in perioperative sleep parameters among an ambulatory surgery population. METHODS:This study is a prospective, observational study of ambulatory patients undergoing orthopedic surgery on an extremity. Study subjects completed three unattended home sleep apnea tests: baseline before surgery, the first night after surgery (N1), and third night after surgery (N3). Anesthesia and surgical teams were blinded to study participation and patients received routine perioperative care. RESULTS:Two hundred three subjects were enrolled and 166 completed the baseline home sleep test. Sixty-six (40.0%) had OSA at baseline, 35 patients received a new diagnosis, and 31 patients had a previous diagnosis of OSA. Of those with a previous diagnosis, 20 (64.5%) were compliant with continuous positive airway pressure therapy. Respiratory event index and SpO2 nadir did not significantly change postoperatively from baseline. Cumulative percentage of time oxygen saturation < 90% significantly increased N1 as compared to baseline for all patients except for those with moderate to severe OSA. CONCLUSIONS:Ambulatory surgery had minimal effect on sleep parameters and there was no increase in adverse events among patients with either treated or untreated OSA. CLINICAL TRIAL REGISTRATION:Registry: ClinicalTrials.gov; Title: Evaluation of Sleep Disordered Breathing Following Ambulatory Surgery; Identifier: NCT01851798; URL: https://clinicaltrials.gov/ct2/show/study/NCT01851798.