Craniofacial and upper airway morphology in adult obstructive sleep apnea patients: A systematic review and meta-analysis of cephalometric studies

Imaging in Orthodontics

Imaging in orthodontics has evolved from cephalometric and extraoral films, manual cephalometric tracings, to digital imaging and intraoral scanners. Software-assisted cephalometric tracings and three-dimensional image analysis have become routine in orthodontic diagnosis and treatment planning. Determination of biologic boundaries of orthodontic treatment and evaluation of temporomandibular joints and airway became part of orthodontic assessment. Use of advanced imaging and software to digitally plan the orthognathic surgery and accurately predict a successful outcome are now integral to orthodontic practice. This article discusses radiographic methods used in cephalometric analysis and craniofacial growth and development for a predictable orthodontic assessment and treatment planning.

The interaction of obesity and craniofacial deformity in obstructive sleep apnea

OBJECTIVE

Both obesity and craniofacial deformity are important etiologies of obstructive sleep apnea (OSA). The present research aimed to explore their interaction and different impacts on OSA severity.

METHODS

A total of 207 consecutive OSA patients (169 males, 38 females) were included in the research. Based on the body mass index (BMI) value, patients were divided into 77 normal-weight patients (BMI <24 kg m^-2), 105 overweight patients (24 ≤ BMI<28 kg m^-2) and 26 obese patients (BMI ≥28 kg m^-2). All accepted overnight polysomnography and standard lateral cephalogram. Cephalometric measurements involved 25 cephalometric variables. The correlations between these cephalometric variables, BMI and the apnea-hypopnea index (AHI) were evaluated.

RESULTS

For the whole sample after controlling for gender and age, stepwise regression analysis showed that the factors affecting AHI were increased BMI, narrowing posterior airway space, inferior displacement of hyoid and elongation of the tongue. When grouped by BMI, normal-weight group exhibited with more reduced maxillary length and mandible length, and steeper mandible plane than overweight and obese patients (p < 0.0167). Obese group showed least skeletal restriction and most prominent soft tissues enlargement (p < 0.0167). However, these skeletal indexes were not statistically correlated with AHI.

CONCLUSIONS

Obesity and skeletal malformations were both etiological factors of OSA, but obesity seemed to have a greater influence on AHI severity in all kinds of obese and thin OSA patients. Only in normal-weight group, it was affected by both cephalometric variables and BMI.

A novel intraoral neuromuscular stimulation device for treating sleep-disordered breathing

Purpose

To ascertain the usefulness of a novel intraoral neuromuscular stimulation device in treating patients with primary snoring and mild obstructive sleep apnoea (OSA). This device uses daytime awake neuromuscular electrical stimulation (NMES) as an application to induce toning of the tongue muscles.

Methods

A prospective cohort study of 70 patients with sleep-disordered breathing was conducted. Objective snoring and respiratory parameters were recorded with 2 consecutive night WatchPat sleep studies before and after treatment. The device was used for 20 min once daily for a 6-week period. Secondary outcome measures using visual analogue scale reporting of snoring by patient and Epworth Sleepiness Score (ESS) were recorded. Quality of life parameters were also noted.

Results

Objective reduction of snoring was noted on the sleep studies in 95% of participants, with an average snoring time reduction of 48%. Subjectively, the visual analogue scale reported by partners’ similarly demonstrated reduction in 95% of the patients with an average reduction of 40%. In a subset of 38 patients with mild OSA, AHI reduced from 9.8 to 4.7/h (52% reduction), ODI 7.8 to 4.3/h (45% reduction), and ESS from 9.0 to 5.1. Adverse effects encountered were minimal.

Conclusion

This prospective cohort study demonstrates a notable improvement in both objective and subjective parameters of snoring and mild OSA in both simple snorers and patients with mild OSA. This device offers a safe and novel approach to reduce snoring and mild OSA by utilising intraoral neuromuscular electrical stimulation. This could be a preferred option for patients as it alleviates the need of using an oral device during sleep.

Trial registration

clinicaltrials.gov identifier NCT03829956

Effects of miniscrew-assisted orthodontic treatment with premolar extractions on upper airway dimensions in adult patients with Class II high-angle malocclusion

INTRODUCTION

The primary aim of this study was to investigate the change in upper airway dimensions and in mandibular position after miniscrew-assisted treatment with premolar extractions in adult patients with Class II high-angle malocclusion. The secondary aim was to determine the correlation between changes in upper airway dimensions and changes in mandibular position in these patients.

METHODS

Eighteen adult patients with Class II high-angle malocclusion (mean ± standard deviation age = 21.2 ± 2.9 years) were selected retrospectively. All patients underwent 4 premolar extractions, and 2 miniscrews were implanted in the maxilla to intrude molar height. Cone beam computed tomography images were taken pretreatment and posttreatment for every patient. The primary outcome variable for the upper airway was the minimal cross-sectional area of the upper airway (CSA_min), and the primary outcome variables for the mandible were mandibular rotation (Mp-SN angle), mandibular horizontal position (SNB angle), and mandibular vertical position (ANS-Me distance).

RESULTS

The CSA_min significantly increased by 47.2 mm² (t = -2.26, P = 0.04) after orthodontic treatment. The mandible significantly rotated counterclockwise by 0.9° (t = 2.20, P = 0.04) after treatment, which consisted of forward movement of 1.2° (t = -4.30, P = 0.00) and upward movement of 1.3 mm (Z = -1.98, P = 0.05). Furthermore, the change of the CSA_min showed a significant correlation with the change of the ANS-Me (P = 0.01).

CONCLUSIONS

By using miniscrews to intrude maxillary molars, orthodontic premolar extraction treatment results in mandibular counterclockwise rotation, and upper airway dimensions increase in Class II high-angle young adult patients. The increase of the upper airway dimensions significantly correlates to the upward movement of the mandible.

Evaluation and Management of Adults with Obstructive Sleep Apnea Syndrome

Obstructive sleep apnea syndrome (OSAS) is a common and underdiagnosed medical condition characterized by recurrent sleep-dependent pauses and reductions in airflow. While a narrow, collapsible oropharynx plays a central role in the pathophysiology of OSAS, there are other equally important nonanatomic factors including sleep-stage dependent muscle tone, arousal threshold, and loop gain that drive obstructive apneas and hypopneas. Through mechanisms of intermittent hypoxemia, arousal-related sleep fragmentation, and intrathoracic pressure changes, OSAS impacts multiple organ systems. Risk factors for OSAS include obesity, male sex, age, specific craniofacial features, and ethnicity. The prevalence of OSAS is rising due to increasing obesity rates and improved sensitivity in the tools used for diagnosis. Validated questionnaires have an important but limited role in the identification of patients that would benefit from formal testing for OSA. While an in-laboratory polysomnography remains the gold standard for diagnosis, the widespread availability and accuracy of home sleep apnea testing modalities increase access and ease of OSAS diagnosis for many patients. In adults, the most common treatment involves the application of positive airway pressure (PAP), but compliance continues to be a challenge. Alternative treatments including mandibular advancement device, hypoglossal nerve stimulator, positional therapies, and surgical options coupled with weight loss and exercise offer possibilities of an individualized personal approach to OSAS. Treatment of symptomatic patients with OSAS has been found to be beneficial with regard to sleep-related quality of life, sleepiness, and motor vehicle accidents. The benefit of treating asymptomatic OSA patients, particularly with regard to cardiovascular outcomes, is controversial and more data are needed.

New frontiers in pharmacologic obstructive sleep apnea treatment: A narrative review

Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing characterized by intermittent partial or complete closure of the upper airway during sleep. If left untreated, OSA is associated with adverse cardiovascular outcomes such as hypertension, coronary heart disease, heart failure, cardiac arrhythmia, stroke, and death. Positive airway pressure (PAP) is often considered the first-line treatment for OSA. While PAP can be very effective in reducing the number of obstructive apneas and hypopneas, its impact on prevention of adverse cardiovascular consequences remains controversial, and treatment adherence is often poor. Hence, the necessity for novel treatment options to help those who cannot adhere to positive airway pressure treatment. Different classes of medications have been tested with regards to their effect on OSA severity. This review 1) provides an update on the epidemiology and pathophysiology of OSA, 2) outlines the mechanistic rationale for medication classes tested as OSA treatment and 3) discusses the effects of these medications on OSA. Several wake-promoting medications are approved for management of persistent sleepiness despite OSA treatment; discussion of these symptomatic treatments is outside the scope of this review. Herein, the authors review the current evidence for pharmacological management of OSA and provide future directions.

Cone beam computed tomographic evaluation of pharyngeal airway in North Indian children with different skeletal patterns

BACKGROUND

In growing patients with skeletal discrepancies, early assessment of functional factors can be vital for the restoration of normal craniofacial growth.

AIM

To compare airway volumes in patients with mandibular retrognathism with the normal anteroposterior skeletal relationship, thereby assessing the association between cephalometric variables and airway morphology.

METHODS

Cone-beam computed tomography volume scans, and lateral cephalograms, 3-dimensional airway volume and cross-sectional areas of 120 healthy children (54 boys and 66 girls mean age 15.19 ± 1.28) which were done for orthodontic assessment were evaluated. The subjects were divided into 2 groups based on the angle formed between point A, Nasion and point B (ANB) values and cephalometric variables (such as anterior and posterior facial height, gonial angle etc.) airway volumes, and cross-sectional measurements were compared using independent t tests. Pearson’s correlation coefficient test was used to detect any relationship of different parts of the airway and between airway volume and 2-dimensional cephalometric variables.

RESULTS

Means and standard deviations for cephalometric, cross-sectional, and volumetric variables were compared. ANB, mandibular body length and facial convexity were statistically highly significant (P < 0.01) whereas condylion to point A, nasal airway and total airway volume (P < 0.05) were statistically significant. The nasal airway volume and the superior pharyngeal airway volume had a positive correlation (P < 0.01), nasal airway was correlated to middle (P < 0.05) and total airway superior had a relation with middle (P < 0.05), inferior and total airway (P < 0.05), middle was related to all other airways; inferior was also related to all the airways except nasal. Lateral cephalometric values were positively correlated with the airway volume with Frankfurt Mandibular Plane Angle and facial convexity showed significant correlations with total airway volume (P < 0.05). Additionally, ANB angle was significantly correlated with total airway volume and superior airway (P < 0.05).

CONCLUSION

The mean total airway volume in patients with retrognathic mandible was significantly smaller than that of patients with a normal mandible.

The Bidirectional Relationship Between Obstructive Sleep Apnea and Chronic Kidney Disease

Sleep apnea is a condition with significant health risks and increased risk of mortality and is prevalent in patients with chronic kidney disease. This paper describes the detrimental cardiovascular sequelae of sleep-disordered breathing and explores the bidirectional relationship between chronic kidney disease and obstructive sleep apnea. Obstructive sleep apnea-related hypoxia produces a range of harmful systemic effects including oxidative stress, inflammation, and sympathetic activation that collectively worsen the progression of renal disease. In turn, chronic kidney disease can result in increased severity of sleep apnea through inducing (1) uremic neuropathy and myopathy, (2) altered chemosensitivity, and (3) hypervolemia. Continuous positive airway pressure therapy remains the mainstay of treatment for reversing the health risks of apnea. Other strategies aimed at decreasing the high prevalence and associated morbidity of sleep apnea include weight loss, oral appliances, and corrective surgery in the case of airway obstruction.

The Need for Head Space: Brachycephaly and Cerebrospinal Fluid Disorders

Brachycephalic dogs remain popular, despite the knowledge that this head conformation is associated with health problems, including airway compromise, ocular disorders, neurological disease, and other co-morbidities. There is increasing evidence that brachycephaly disrupts cerebrospinal fluid movement and absorption, predisposing ventriculomegaly, hydrocephalus, quadrigeminal cistern expansion, Chiari-like malformation, and syringomyelia. In this review, we focus on cerebrospinal fluid physiology and how this is impacted by brachycephaly, airorhynchy, and associated craniosynostosis.

Machine learning for image-based detection of patients with obstructive sleep apnea: an exploratory study

PURPOSE

In 2-dimensional lateral cephalometric radiographs, patients with severe obstructive sleep apnea (OSA) exhibit a more crowded oropharynx in comparison with non-OSA. We tested the hypothesis that machine learning, an application of artificial intelligence (AI), could be used to detect patients with severe OSA based on 2-dimensional images.

METHODS

A deep convolutional neural network was developed (n = 1258; 90%) and tested (n = 131; 10%) using data from 1389 (100%) lateral cephalometric radiographs obtained from individuals diagnosed with severe OSA (n = 867; apnea hypopnea index > 30 events/h sleep) or non-OSA (n = 522; apnea hypopnea index < 5 events/h sleep) at a single center for sleep disorders. Three kinds of data sets were prepared by changing the area of interest using a single image: the original image without any modification (full image), an image containing a facial profile, upper airway, and craniofacial soft/hard tissues (main region), and an image containing part of the occipital region (head only). A radiologist also performed a conventional manual cephalometric analysis of the full image for comparison.

RESULTS

The sensitivity/specificity was 0.87/0.82 for full image, 0.88/0.75 for main region, 0.71/0.63 for head only, and 0.54/0.80 for the manual analysis. The area under the receiver-operating characteristic curve was the highest for main region 0.92, for full image 0.89, for head only 0.70, and for manual cephalometric analysis 0.75.

CONCLUSIONS

A deep convolutional neural network identified individuals with severe OSA with high accuracy. Future research on this concept using AI and images can be further encouraged when discussing triage of OSA.

Decreased maxillary sinus volume is a potential predictor of obstructive sleep apnea

OBJECTIVES

To investigate the associations between nasal airway volume and the presence and severity of obstructive sleep apnea (OSA) in adults.

MATERIALS AND METHODS

The medical records of adult patients who visited the sleep clinic at University Hospital between June 2013 and April 2017 and underwent overnight polysomnography for the diagnosis of obstructive sleep apnea were reviewed retrospectively. Using computed tomography, the volumes of the nasal airways and maxillary sinuses were measured, and associations with the presence and severity of OSA were analyzed while controlling for the effects of possible confounders such as lateral cephalometric variables, maxillary widths, tongue/hyoid position, and soft palate dimensions.

RESULTS

Comparison between normal subjects and patients with OSA revealed that the latter had decreased ratios of maxillary sinus volume to whole nasal airway volume (P = .029) than normal subjects. OSA severity was greater in those with inferior positions of the hyoid (P = .010), in older patients (P = .011), and in those with high body mass index (P = .001). The volume of the total nasal airway or maxillary sinuses were not associated with OSA severity.

CONCLUSIONS

A decreased ratio of maxillary sinus volume to whole nasal airway volume is associated with adult OSA. However, OSA severity is not associated with either maxillary sinus volume or whole nasal airway volume.

Prototype of Customized Mobile Application for Obstructive Sleep Apnea (OSA) Risk Assessment During the COVID-19 Pandemic

Obstructive sleep apnea (OSA), the most prevalent form of sleep-related breathing disorder (SRBD), is associated with cardiovascular, neurocognitive, and metabolic complications. Evidence suggests that these comorbidities are also risk factors for enhanced severity in COVID-19 patients. Hence, initial diagnosis or screening of OSA-risk is a major requirement of current times, which can be fulfilled by a noncommercial, easily accessible mobile application for self-assessment of OSA-risk. The current article mentions a prototype of an “OSA-Risk Assessment Tool,” a mobile application developed after prior testing of needs analysis and comprising various interfaces for OSA-risk assessment in all age groups, and further refined for user applicability through a cognitive, pluralistic walkthrough and heuristic evaluation by the authors and four volunteers. It has huge scope of application in orthodontic clinics, primary healthcare centers in middle and low-income strata of developing countries, and multiple educational and licensing institutions for the larger benefit of the society.

Craniofacial and Craniocervical Features in Cartilage-Hair Hypoplasia: A Radiological Study of 17 Patients and 34 Controls

BACKGROUND

Biallelic mutations in the non-coding RNA gene RMRP cause Cartilage-hair hypoplasia (CHH), a rare skeletal dysplasia in which the main phenotypic characteristic is severe progressive growth retardation.

OBJECTIVE

This study compared the cranial dimensions of individuals with CHH to healthy subjects.

METHODS

Lateral skull radiographs of 17 patients with CHH (age range 10 to 59 years) and 34 healthy individuals (age range 10 to 54 years) were analyzed for relative position of the jaws to skull base, craniofacial height and depth, as well as vertical growth pattern of the lower jaw, anterior cranial base angle, and the relationship between the cervical spine and skull base.

RESULTS

We found that the length of the upper and lower jaws, and clivus were significantly decreased in patients with CHH as compared to the controls. Anterior cranial base angle was large in patients with CHH. Basilar invagination was not found.

CONCLUSION

This study found no severe craniofacial involvement of patients with CHH, except for the short jaws. Unexpectedly, mandibular deficiency did not lead to skeletal class II malocclusion.

CLINICAL IMPACT

Although the jaws were shorter in patients with CHH, they were proportional to each other. A short posterior cranial base was not associated with craniocervical junction pathology.

Dysphagia in a persistently vegetative patient improved by orthodontic treatment of severe dental misalignment

INTRODUCTION

We describe the treatment of severe dysphagia in a patient left in a persistent vegetative state after an episode of hypoxic-ischemic encephalopathy following a traffic accident.

CASE REPORT

A 38-year-old man was in a persistent vegetative state since a traffic accident in 2005, which resulted in cardiopulmonary arrest and hypoxic-ischemic encephalopathy. His airway had been secured with a tracheostomy, and a gastric tube had been inserted; however, he continued to suffer from urinary tract infections, glossoptosis, and silent aspiration of saliva. Both the maxilla and mandible had very narrow dental arches, with the mandibular incisors exhibiting severe lingual inclination.

COURSE

We first corrected the dentition in the narrow maxillary arch, followed by the mandibular arch. As the dental alignment improved, tongue movements appeared during oral care, and endoscopy also revealed signs of an active saliva swallowing reflex.

DISCUSSION

The "training approach" generally used to treat severe dysphagia is usually impossible in persistently vegetative patients. In our patient, the tongue movements and saliva swallowing reflex appeared after we expanded the narrow dental arches, suggesting that an orthodontic approach can be effective in such cases. Our findings can be applied to similar cases of vegetative patients to facilitate better oral care and outcomes.

Critical issues concerning biocreative strategy in contemporary temporary skeletal anchorage device orthodontics: A narrative review

Biocreative Orthodontic Strategy (BOS) is designed to establish a physiologically stable occlusion in harmony with masticatory and TMJ function and healthy supporting tissues with strategic use of temporary skeletal anchorage devices (TSADs). This narrative review surveys current research that demonstrates how BOS with TSADs uses a target approach to overcome the limitations experienced with conventional orthodontic treatment. A narrative review article including research on TSADs orthodontics in the permanent dentition. This review is a brief survey of five BOS principles for contemporary TSAD orthodontics: elegant selection of TSADs, bracket prescription to enhance TSAD orthodontics, antero-posterior dimension control, transverse dimension control and airway control issues. Severe malocclusion and craniofacial dysmorphology can be treated with Biocreative Orthodontic Strategy with a minimum number of TSADs. In order to achieve successful treatment outcome using TSADs, it is critical to understand the key diagnosis and treatment principles of BOS and how to develop a target approach for the tooth and bone movement.

Screening of obstructive sleep apnea (OSA) risk in adolescent population and study of association with craniofacial and upper airway morphology

Background

Obstructive sleep apnea (OSA) is a common form of sleep-disordered breathing with high prevalence and associated co-morbidities. It still goes largely under-reported due to events occurring in sleep and difficulty in identifying predisposing factors.

Aims

To perform questionnaire-based screening of OSA-risk in adolescents and study association of OSA-risk with craniofacial and upper airway morphology.

Material and methods

Modified STOP-BANG questionnaire was used for screening OSA-risk in adolescent orthodontic patients (10-19 years) in a government dental hospital in India. Patients were categorised into two groups: OSA-risk and non-risk, based on the questionnaire scores, and were subsequently evaluated for craniofacial and upper airway morphology, both on examination and on lateral cephalometric radiographs.

Results

Documented a high prevalence of 14% for OSA-risk in adolescent orthodontic patients. The extra-oral and intra-oral parameters found significantly associated with OSA-risk were convex profile [Odd's ratio (OR) - 3.824], steep mandibular plane angle [MPA] (OR- 79.75), Type 3/4 faucial pillars (OR- 11.227), Class II molar relationship (OR - 4.518), ovoid upper arch form (OR - 13.750). In addition, the cephalometric parameters: ANB (p- 0.025), SN-MP (p- 0.007), BA-SN (p- 0.020), PNS-AD1 (p < 0.001), PNS-AD2 (p - 0.001) also showed highly significant association to OSA-risk. The ROC curves demonstrated high sensitivity and specificity for PNS-AD1 (60%,83.3%), PNS-AD2 (73.3%, 70%) and SN-MP (60%,70%), respectively for OSA-risk.

Conclusions

The study supported applicability of modified STOP-BANG questionnaire for OSA-risk in Indian adolescents. The parameters [extra-oral, intra-oral, cephalometric and upper airway (PNS-AD1, PNS-AD2, SN-MP)] significantly associated with OSA-risk, were identified.

Combined orthodontic and surgical treatment for a patient with Hallermann-Streiff-Francois syndrome, severe obstructive sleep apnea, and history of antiresorptive medication

Micrognathia and retrognathia, as observed in patients with the Hallermann-Streiff-Francois syndrome, might result in obstructive sleep apnea syndrome. When it becomes severe (apnea-hypopnea index [AHI], ≥30), noninvasive treatment options might be insufficient. An orthognathic treatment with mandibular advancement will increase the upper airway volume, which results in a decrease of apneas. A 53-year-old woman with Hallermann-Streiff-Francois syndrome and a history of antiresorptive medication suffered from severe obstructive sleep apnea (AHI, 77.7). She was treated with a combined orthodontic and surgical approach. The AHI decreased to 1, and the patient felt fitter after treatment. No medication-induced osteonecrosis nor inhibition of tooth movement was seen. A combined orthodontic and surgical treatment of a patient with severe obstructive sleep apnea was a good treatment choice. With a history of antiresorptive medication, the risks related to these medications have to be weighed up against the consequences of not treating obstructive sleep apnea syndrome. With a drug holiday, successful surgical treatment can be achieved.

Effectiveness of Continuous Positive Airway Pressure Versus Mandibular Advancement Device in Severe Obstructive Sleep Apnea Patients With Mandibular Retrognathia: A Prospective Clinical Trial

AIM

Some obstructive sleep apnea (OSA) patients may have mandibular retrognathia (ANB > 4.7° and SNB < 76.2°). Currently, there are no studies that have compared the effectiveness of continuous positive airway pressure (CPAP) versus mandibular advancement device (MAD) in severe OSA patients with mandibular retrognathia. We explored the efficacy of CPAP versus MAD for the treatment of severe OSA patients with mandibular retrognathia.

METHODS

A total of 105 patients were enrolled. Outcomes were assessed by using polysomnography, Epworth Sleepiness Scale (ESS), Snore Scale (SS), Self-rating Anxiety Scale (SAS), and compliance, before treatment and after 6 and 12 months of treatment.

RESULTS

Continuous positive airway pressure was superior to MAD in improving polysomnographic outcomes and SS score, but reported compliance was higher on MAD. There is no significant difference between the 2 treatments in terms of ESS score and SAS score. Obstructive sleep apnea patients with mandibular retrognathia showed greater improvement than those without mandibular retrognathia in terms of apnea-hypopnea index and oxygen desaturation index after MAD.

CONCLUSION

Continuous positive airway pressure and MAD are both effective in treating severe OSA patients with mandibular retrognathia. Mandibular advancement device is a good alternative to CPAP in severe OSA patients with mandibular retrognathia. Mandibular advancement device is more effective in treating OSA patients with mandibular retrognathia than those without. Trial registration: ChiCTR2000032541.

Is There an Increase in the Risk of Obstructive Sleep Apnea After Isolated Mandibular Setback Surgery? An Evaluation Using the STOP-BANG Questionnaire

PURPOSE

The aim of this study was to assess the impact of isolated mandibular setback surgery on the risk of obstructive sleep apnea (OSA), using the STOP-BANG questionnaire (SBQ).

PATIENTS AND METHODS

The authors implemented a double-blinded prospective quasi-experimental study. All healthy patients with skeletal Class III deformity older than 18 years were included in this study. They were candidates for isolated mandibular setback surgery. The SBQ was completed by the pulmonologist, 1 week preoperatively (T0), and 1 and 6 months postoperatively (T1 and T2, respectively). The mandibular setback displacement was the study intervention. The risk of OSA on the basis of the SBQ was the outcome variable. Descriptive and bivariate statistics were computed and the significance level was set at .05.

RESULTS

The sample comprised 30 patients (15 females, 15 males) with the average age of 25.77 ± 4.76. The mean score of SBQ at T0 was 1.37 ± 0.85, which increased to 2.33 ± 1.52 at T1 interval. However, it decreased significantly to 1.47 ± 1.17 at T2 interval (P < .001). T0-T1 and T0-T2 score differences were observed to be higher in the group with a mandibular setback repositioning greater than or equal to 5 mm (P < .005).

CONCLUSIONS

An isolated mandibular setback surgery less than 5 mm does not increase the risk for OSA in a young healthy nonsmoker Class III patient, according to the SBQ. Moreover, there was a significant increase in the risk for OSA when the setback was greater than or equal to 5 mm, measured at the mandibular incisor edge. Therefore, clinicians should be careful and discuss this potential increased risk with the patients, when this movement is required by the treatment plan. Further clinical trials are needed to support the relevancy.

Advanced interdisciplinary treatment protocol for pediatric obstructive sleep apnea including medical, surgical, and orthodontic care: a narrative review

OBJECTIVE

To suggest an updated interdisciplinary treatment protocol for pediatric obstructive sleep apnea (POSA) based on the integration of craniofacial growth modification into medical and surgical sleep practice.

METHODS

PubMed, Scopus, and Cochrane library were searched up to February 2020 using keywords. Among 184 articles, 80 studies were finally included. An integrated treatment protocol for POSA encompassing craniofacial skeletal management as well as medical and surgical care was attempted.

RESULTS

A differential diagnostic workflow for identifying the phenotype of POSA was suggested, and a phenotype-based treatment protocol for POSA was proposed. Despite the lack of high level of evidence, timely skeletal growth modification in three dimensions using craniofacial growth potential could be valuable treatment for upper airway development in POSA patients with craniofacial phenotypic cause.

CONCLUSION

A novel precision treatment protocol will advance clinicians to determine the primary option or to apply the combined strategy for POSA patients.

Upper airway lengthening caused by weight increase in obstructive sleep apnea patients

BACKGROUND

The longer upper airway is more collapsible during sleep. This study aims to reveal relationships among upper airway length, weight, and obstructive sleep apnea (OSA), particularly to answer why the upper airway of OSA patients is longer than that of healthy people and why some obese people suffer from OSA while others do not.

METHODS

We perform head and neck MRI on male patients and controls, and measure > 20 morphological parameters, including several never before investigated, to quantify the effect of weight change on upper airway length.

RESULTS

The upper airway length is longer in patients and correlates strongly to body weight. Weight increase leads to significant fat infiltration in the tongue, causing the hyoid to move downward and lengthen the airway in patients. The apnea-hypopnea index (AHI) strongly correlates to airway length and tongue size. Surprisingly, a distance parameter h and angle β near the occipital bone both show significant differences between healthy males and patients due to their different head backward tilt angle, and strongly correlates with AHI. The contributions of downward hyoid movement and head tilt on airway lengthening are 67.4-80.5% and19.5-32.6%, respectively, in patients. The parapharyngeal fat pad also correlates strongly with AHI.

CONCLUSIONS

The findings in this study reveal that the amount of body weight and distribution of deposited fat both affect airway length, and therefore OSA. Fat distribution plays a larger impact than the amount of weight, and is a better predictor of who among obese people are more prone to OSA.

Clinical Radiographic Predictors of Response to Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea

OBJECTIVE

To determine if clinically acquired cephalometric measurements, specifically soft palate size, can predict hypoglossal nerve stimulation outcomes.

STUDY DESIGN

Combined prospective cohort study and retrospective review.

SETTING

US sleep otolaryngology training program.

METHODS

Adults with obstructive sleep apnea and apneahypopnea index greater than 15 events/h who underwent hypoglossal nerve stimulation. Eligible subjects had diagnostic preoperative sleep studies and full-night efficacy postoperative studies for analysis. Lateral neck x-rays were obtained as part of routine clinical care and measured for key cephalometric variables by trained head and neck radiologists. Continuous variables were compared using the Student t test, while χ² testing was used for categorical variables.

RESULTS

Fifty-one patients met all study criteria. On average, patients were white, middle aged, and overweight. Following hypoglossal nerve stimulation, the overall cohort achieved a significant apnea-hypopnea index reduction from 36.7 events/h to 20.6 events/h (P < .01) and a response rate of 47% (defined as apnea-hypopnea index reduction >50% and apnea-hypopnea index <20 events/h). On average, therapy responders had significantly thinner soft palates than nonresponders (13.4 ± 3.8 mm vs 16.0 ± 3.4 mm, P = .045).

CONCLUSIONS

Patient-specific anatomic factors, specifically soft palate thickness, may help identify optimal candidates for hypoglossal nerve stimulation. A larger, prospective study including both anatomic and physiologic variables is required to validate these findings.

Intermediate phenotypes of childhood obstructive sleep apnea

An intermediate phenotype of a disease is a trait in the path of pathogenesis from genetic predisposition to disease manifestation. Identifying intermediate phenotypes with high heritability is helpful in delineating the genetics of a disorder. In this study, we aimed to examine various traits with regards to obesity, cardiovascular risk and upper airway structure to identify potential intermediate phenotypes of childhood obstructive sleep apnea (OSA). Children aged between 6 and 18 years and their parents and siblings were recruited. All subjects underwent anthropometric measurements, cardiovascular risk assessment, sonographic measurement of lateral parapharyngeal wall (LPW) thickness, X-ray cephalometry and overnight polysomnography. A total of 34 phenotypes were examined. One hundred and one families consisting of 127 children (46 overweight) and 198 adults (84 overweight) were recruited. Heritability of obstructive apnea-hypopnea index (OAHI) was significant in overweight (h²  = 0.54) but not normal-weight individuals (h²  = 0.12). LPW thickness (h²  = 0.68) and resting blood pressure (h²  = 0.36 and 0.43 for systolic blood pressure [SBP] and diastolic blood pressure [DBP], respectively) were significantly heritable and associated with OAHI. Moreover, these traits were found to have shared genetic variance with OAHI in the overweight subgroup. Hyoid bone position also had significant heritability (h²  = 0.55) and association with OAHI but genetic correlation with OSA severity was not demonstrated. These findings suggest that LPW thickness and resting blood pressure are possible intermediate phenotypes of OSA independent of body mass index, especially in overweight patients. Identifying genes relevant to these phenotypes may help to elucidate the genetic susceptibility of OSA.

Obstructive sleep apnea and respiratory center regulation abnormality

PURPOSE

Obstructive sleep apnea (OSA) is a complex disease in which phenotypic analysis and understanding pathological mechanisms facilitate personalized treatment and outcomes. However, the pathophysiology responsible for this robust observation is incompletely understood. The objective of the present work was to review how respiratory center regulation varies during sleep and wakeness in patients with OSA.

DATA SOURCES

We searched for relevant articles up to December 31, 2019 in PubMed database.

METHODS

This review examines the current literature on the characteristics of respiratory center regulation during wakefulness and sleep in OSA, detection method, and phenotypic treatment for respiratory center regulation.

RESULTS

Mechanisms for ventilatory control system instability leading to OSA include different sleep stages in chemoresponsiveness to hypoxia and hypercapnia and different chemosensitivity at different time. One can potentially stabilize the breathing center in sleep-related breathing disorders by identifying one or more of these pathophysiological mechanisms.

CONCLUSIONS

Advancing mechanism research in OSA will guide symptom research and provide alternate and novel opportunities for effective treatment for patients with OSA.

Characterization and classification of different female hairline patterns in the Thai population

BACKGROUND

The hairline is an essential component of the human face. Disfigurement of the hairline may cause physical and psychological problems. Standard guidelines do not exist for female hairline designs, average values of infratemporal portion, hairline classifications, and preferences.

AIMS

We aimed to study hairline characteristics in Thai females and further compare the values with previous studies in different populations. Furthermore, we aimed to introduce a comprehensive hairline classification system that allowed an easy and detailed phenotypic characterization of female hairline.

PATIENTS/METHODS

Healthy Thai females aged over 18 years were included in the study. Collection of demographic data, infratemporal measurements, and standard photography was performed. All collected data were analyzed to determine the standard values of each hairline dimension for comparison to previous studies.

RESULTS

Two hundred and twenty-nine females, with a mean age of 32.4 ± 8.6 years, participated in this study. The mean mid-frontal line was 6.45 ± 0.89 cm, which was not correlated with age. Lateral mounds, widow's peaks, and cowlicks were observed in 42.35%, 24.45%, and 1.74% participants, respectively. Our study revealed five patterns of the frontal hairline and four patterns of the temporal hairline. The mid-frontal line in Asian females trended longer than that in Caucasians, without statistical significance.

CONCLUSIONS

Measurements of the infratemporal portions in Thai females revealed no change with age, and the mid-frontal line showed no statistically significant differences between Korean and Turkish participants. The hairline classification system introduced in our study was comprehensive and would be easily applicable in clinical practice. Female hairline dimensions and patterns reported in our study could provide reference values for hairline design in hairline restoration surgery as well as assist in accurate diagnosis of hair disorders.

Dental sleep medicine: Time to incorporate sleep apnoea education in the dental curriculum

Dental sleep medicine is a discipline that includes conditions such as sleep breathing disorders (eg snoring and sleep apnoea), sleep bruxism, orofacial pain and sleep-related complaints, and to some extent gastro-oesophageal reflux disorder and/or insomnia. Obstructive sleep apnoea (OSA) is a life-threatening condition that dentists need to identify and manage when indicated in order to increase patient well-being and to be taken in consideration in the dental curriculum. The main objective of this paper is to highlight the relevance of dental sleep medicine in the context of dental education, and to discuss potential educational content for integration in the dental curriculum with a focus on OSA, a condition that is not yet integrated in many dental training curricula around the world.

Respiratory and sleep characteristics based on frequency distribution of craniofacial skeletal patterns in Korean adult patients with obstructive sleep apnea

Objective

To investigate the frequency distribution of various craniofacial skeletal patterns in a large Korean adult obstructive sleep apnea (OSA) population, and to find a relationship between craniofacial risks and respiratory and sleep characteristics.

Methods

A total of 1226 OSA patients (mean age of 44.9±13.3 years) were included in this retrospective cross-sectional study. All subjects were evaluated for gender and age using fourteen polysomnographic, five cephalometric, two comorbid variables, and three self-reported indexes. Frequency analysis was used to screen the distribution of main skeletal patterns and subtypes. Intergroup comparisons were performed using independent t-test, chi-square test or analysis of variance. Univariable regression analysis was done to find a relationship between skeletal risks and OSA characteristics.

Results

The frequency distribution of skeletal patterns was as follows: sagittally 57.2%, 32.3%, and 10.5% of Class II, Class I, and Cass III; vertically 54.0%, 26.7%, and 19.3% of hyperdivergent, normodivergent, and hypodivergent type, respectively. Polysomnographic, symptomatic, and comorbid variables showed no differences among patients with different skeletal patterns. Conversely, skeletal variables showed no differences according to OSA severity. The prevalence of highly risky skeletal pattern of hyperdivergent Class II was more likely to be females (OR 4.52, P < .01) and less obese (OR 3.21, P < .01), irrelevant to OSA and sleep characteristics.

Conclusion

Characteristic frequency distributions of skeletal patterns and subtypes were observed in adult OSA patients however, no statistical association was found between the skeletal patterns and OSA characteristics due to the large interindividual variation.

Imaging of sleep-disordered breathing in adults

Sleep-disordered breathing (SDB) is a term that includes several chronic conditions in which partial or complete cessation of breathing occurs multiple times throughout the night. Central sleep apnoea (CSA) is uncommon and defined by the episodic cessation of airflow without respiratory effort. Lesions involving the respiratory centre in the brainstem or the origin of the phrenic nerve from the mid-cervical cord are the commonest structural causes of CSA; magnetic resonance imaging (MRI) will demonstrate the lesion and frequently suggest the likely aetiology. In contrast, obstructive sleep apnoea (OSA) is defined as upper airway obstruction despite ongoing respiratory effort. Repetitive episodes of narrowing or closure of the upper airway are the predominant cause leading to snoring and OSA, respectively. OSA affects 33-40% of the adult population and is associated with multiple adverse health consequences, including a significantly increased risk of serious morbidity and mortality. The incidence is increasing proportionally to the worldwide rise in obesity. Imaging, performed primarily without the involvement of radiologists, has been integral to understanding the anatomical basis of SDB and especially OSA. This article will review the pathophysiology, imaging findings, and sequelae of these common conditions. The role of imaging both in suggesting the incidental diagnoses of SDB and in the investigation of these conditions when the diagnosis is suspected or has been established are also discussed.

Surgically Facilitated Orthodontic Therapy (SFOT): Diagnosis and Indications in Interdisciplinary Dentofacial Therapy Involving Tooth Movement

FOCUSED CLINICAL QUESTION

What are the key considerations for the interdisciplinary dentofacial therapy (IDT) team in the diagnostic process to evaluate a patient for surgically facilitated orthodontic therapy (SFOT)?

SUMMARY

SFOT creates a demineralized bone matrix and augments dentoalveolar deficiencies in the management of dentofacial disharmony malocclusion. Numerous indications and contraindications exist which are essential to the periodontal surgeon for proper case selection. A collaboratively focused workup by an IDT team is equally essential. Cone beam computed tomography (CBCT) and orthodontic simulation software which identifies changes in the dentoalveolar complex influenced by tooth movement are critical in providing transparency to the patient and IDT team during the treatment planning process. Such transparency can aid the team in assessing goals and outcomes that consider and respect foundational dentoalveolar parameters while contributing to sustainable outcomes.

CONCLUSIONS

The SFOT IDT decision making process is complex, yet full of opportunities. Embracing SFOT IDT with innovative and novel 3D technology can optimize conditions leading to long-term outcomes that align with periodontal stability as well as patient goals and preferences which permeate beyond the achievement of "straightening teeth". Transparency of complex IDT through 3D CBCT and orthodontic simulation software engenders "collaborative accountability" and can improve patient communication which is critical to developing meaningful and essential treatment plans.

Mandibular movement analisys by means of a kinematic model applied to the design of oral appliances for the treatment of obstructive sleep apnea

BACKGROUND

Mandibular advancement devices (MADs) are one of the treatment options used for the obstructive sleep apnea syndrome (OSAS). At present, MADs are designed with standard titration systems, without considering each patient's anatomical characteristics of the temporomandibular joint and mandible shape. The main objective of this study is to evaluate if a variability in mandibular morphology will influence the displacement of the jaw with a MAD. Such knowledge will be of help to find optimal mandibular positions with MAD even when opening the mouth.

METHODS

By using a mandibular movement model, the movement patterns of different points on the chin have been analyzed. The influence of different skeletal mandibular shapes on these movements have also been studied. The results show differences in the movement patterns of the lower front teeth depending on its distance to the center of the condyle, with a more horizontal direction in those in which there is a greater distance.

RESULTS

Variations in mandibular morphology imply differences in movement patterns of the analyzed points of the mandible. Consequently, MADs should be designed according to each patient's anatomy to avoid mandibular retrusion in those areas that may narrow the upper airways.

CONCLUSIONS

This study may help to understand why not all patients move their lower jaws forwards equally with the same degree of mandibular protrusion measured in relation to the teeth. These results might also partially explain why airway obstruction is more severe in certain untreated sleep apnea subjects than in others when opening their mouth during sleep.

Association of cervical spondylosis with obstructive sleep apnea

OBJECTIVE

The study objective was to evaluate the association between cervical spondylosis (CS) and a subsequent diagnosis of obstructive sleep apnea (OSA) in light of the expected constricting impact of CS-associated cervical spine changes on the pharyngeal airway space, a key contributor to OSA.

METHODS

Data were retrieved from the Taiwan National Health Insurance Research Dataset. A total of 98,234 patients who newly received a diagnosis of OSA were identified. We identified four propensity score-matched controls per OSA patient (n = 392,936). Chi-square tests were used to compare cases and controls on sociodemographic characteristics, and multivariable logistic regression modelling to examine the association of OSA with prior CS.

RESULTS

Of the 98,234 sampled patients, 18,070 (18.4%) patients had a prior CS diagnosis, significantly different among cases compared to controls, being 18.4% and12.1%, respectively, p < 0.001. Logistic regression analysis showed an adjusted odds ratio (OR) of prior CS of 1.778 (95% confident interval (CI): 1.744-1.814) relative to controls. The adjusted odds of prior CS without myelopathy was 1.764 for cases relative to controls (95% CI: 1.727-1.801), and for prior CS with myelopathy (adjusted OR: 1.778, 95% CI: 1.721-1.837). Analysis stratified by age showed that in the 45-64- and >64-year age groups, the adjusted ORs of CS were 1.803 (95% CI: 1.758-1.850) and 1.634 (95% CI: 1.568-1.703), respectively, for cases relative to controls.

CONCLUSIONS

Our results suggest that OSA is associated with prior CS. The results call for professionals to be alert to the possibility of subsequent development of OSA among patients with CS.

Upper airways evaluation in young adults with an anterior open bite: A CBCT retrospective controlled and cross-sectional study

OBJECTIVE

To compare the dimensions of the upper airway in young adults with anterior open bite versus matched individuals with an adequate overbite (control group) using different measurement approaches (linear, area, and volume measures).

MATERIALS AND METHODS

The sample included 137 cone-beam computed tomographies (CBCTs) of young adults (74 men and 63 women) divided into two groups: 47 CBCTs of individuals (mean age 27.89) with open bite (overbite depth indicator (ODI) 56.84°±9.48° and Frankfort mandibular plane angle (FMA) 31.21°±6.44°) and 90 CBCTs of individuals (mean age 26.87) without an open bite (ODI 62.24°±9.47°, FMA 26.79°±5.81°). Two trained and calibrated orthodontists made all linear, area, and volume measurements on the CBCT records of the upper airways using Planmeca Romexis software. The Mann-Whitney U-test, chi-squared test, and multiple linear regression were applied. Significance was set at P<0.05.

RESULTS

There were no differences in linear or volume measurements between groups, but there was a greater area in the open bite group (greater mean difference between groups 928.3 mm²) than the control group. No variable influenced nasopharyngeal airway volume, but ANB angle affected oropharyngeal airway volume (β=-623.87) and total airway volume (β=-651.48).

CONCLUSIONS

Orthodontists should be aware that the airways diagnosis can vary depending on the measurement approach used, the volumetric method being the gold standard. The pharyngeal airway volume was similar in individuals with vs. without an open bite and is mainly influenced by ANB angle in both groups.

Clustering-based characterization of clinical phenotypes in obstructive sleep apnoea using severity, obesity, and craniofacial pattern

OBJECTIVES

To identify and characterize the phenotypes of adult obstructive sleep apnoea (OSA) patients based on clustering using OSA severity, obesity, and craniofacial pattern.

MATERIAL AND METHODS

The samples consisted of 89 adult OSA patients whose polysomnography and lateral cephalogram were available. With cluster analysis using apneahypopnea index (AHI, events/hour), body mass index (BMI, kg/m2), ANB (degree), and mandibular plane angle (MPA, degree), three clusters were identified. Cephalometric variables including craniofacial, soft palate, hyoid bone, and pharyngeal space compartments were compared among clusters by one-way analysis of variance or Kruskal-Wallis test. Multivariable linear regression analysis was performed to find contributing factors to OSA severity within each cluster.

RESULTS

Cluster-1 (obesity type; 49.4 per cent) exhibited moderate OSA, obesity, and normal sagittal and vertical skeletal pattern (AHI, 22.4; BMI, 25.5; ANB, 3.2 degrees; MPA, 26.3 degrees) without significant upper airway abnormality. Cluster-2 (skeletal type; 33.7 per cent) was characterized by moderate OSA, severe skeletal Class II hyperdivergent pattern with narrow pharyngeal airway spaces, without obesity (AHI, 27.9; BMI, 23.5; ANB, 7.5 degrees; MPA, 36.6 degrees). Cluster-3 (complex type; 16.8 per cent) included severe OSA, obesity, skeletal Class II hyperdivergent pattern (AHI, 52.8; BMI, 28.0; ANB, 4.5 degrees; MPA, 32.2 degrees), with posteriorly displaced hyoid and retroclined soft palate. The main contributing factors to AHI were obesity in Cluster-1; hyperdivergent vertical pattern with narrow pharyngeal space in Cluster-2; and hyperdivergent pattern, obesity, displaced hyoid, and soft palate in Cluster-3.

CONCLUSION

Three OSA phenotypes resulted from this study provide a clinical guideline for differential diagnosis and orthodontic intervention in the interdisciplinary treatment for OSA patients.

Relationship between cephalometric parameters and the apnoea-hypopnoea index in OSA patients: a retrospective cohort study

OBJECTIVE

The purpose of this study was to assess the relationship between cephalometric parameters and apnoea-hypopnoea index (AHI) controlling for the effect of gender, age, and body mass index (BMI) on a large sample of patients with obstructive sleep apnoea (OSA).

METHODS

This retrospective cohort study was conducted on the lateral cephalograms of 253 Caucasian adult OSA patients. Cephalometric analyses were performed using 14 parameters for skeletal and soft tissue morphology, including antero-posterior and vertical jaw relationships, hyoid bone position, soft palate length and thickness, airway space, and tongue length and height. A hierarchical regression was run to examine the amount of variability in AHI that cephalometric variables explained after controlling for patients' general characteristics (gender, age, and BMI).

RESULTS

After controlling for gender, age, and BMI, the increase in AHI variance accounted for by cephalometric parameters was equal to 0.103. Among the cephalometric variables, only MP-H and PNS-P were statistically significant (P < 0.05).

LIMITATIONS

Given the retrospective nature of the study, it is difficult to assess whether other confounding variables not considered in the present study could have influenced the relationship between cephalometric parameters and AHI.

CONCLUSIONS

This study revealed the existence of a relationship between OSA severity and some cephalometric parameters. Indeed soft palate length and vertical position of the hyoid bone were significant predictors of AHI in adult Caucasian OSA patients.

Comparison of anterior mandible anatomical characteristics between obstructive sleep apnea patients and healthy individuals: a combined cone beam computed tomography and polysomnographic study

PURPOSE

This study aims to evaluate the morphology of the genial tubercle (GT) and lingual foramen (LF) between obstructive sleep apnea (OSA) and non-OSA patients for considerations of mandibular advancement surgery.

METHODS

Cone beam CT records of 198 patients were retrospectively collected and analyzed. Five variables were measured for genial tubercle; anterior mandible thickness (AMT), the distance from the lower incisors to the superior border of the genial tubercle, the distance from the inferior border of the genial tubercle to inferior border of the mandible, the height of GT, and genial tubercle width. Lingual foramen were classified according to the genial tubercle. The frequencies, distances of lingual foramen to alveolar crest, lower border of mandible (LVDL) and diameter of LF were also measured.

RESULTS

Significant differences was found for genial tubercle width, anterior mandible thickness, and the distance of lower mandibular border to the midline lingual foramina between OSA and non-OSA patients (p < 0.05). AMT gets thicker and GT gets narrower in OSA patients (p < 0.05). A linear regression analysis on the apnea hypopnea index with measured anatomical variables showed the LVDL (R = - 0.355*), body mass index (R = 0.254), and age (R = 0.33) showed a statistically significant association (p < 0.05). None of the other variables reached formal significance.

CONCLUSION

LVDL is linearly associated with sleep apnea severity. The variable dimensions and anatomy of genial tubercle as well as lingual foramen for OSA patients suggest the need of 3D preoperative radiological evaluation before genioglossus advancement surgery. Cone beam CT can be a powerful low radiation dose tool both for evaluating the anatomy of the upper airway and mandibular structures at the same time for OSA patients.

Obstructive Sleep Apnea, Hypertension, and Cardiovascular Risk: Epidemiology, Pathophysiology, and Management

PURPOSE OF REVIEW

Given the rising prevalence of obstructive sleep apnea (OSA), we aimed to review the epidemiologic and pathophysiologic relationship of OSA, hypertension, and cardiovascular disease, and to summarize recent advances in the treatment of OSA.

RECENT FINDINGS

OSA is associated with an elevated risk of hypertension and cardiovascular disease. Several pathophysiologic factors contribute to the relationship between OSA and vascular risk, including neurohormonal dysregulation, endothelial dysfunction, and inflammation. While CPAP reduces blood pressure, it has not been demonstrated to reduce cardiovascular risk. The combination of CPAP and weight loss has a synergistic effect on blood pressure and several metabolic parameters. Adherence to CPAP is poor across studies, potentially contributing to the attenuation of perceived cardiovascular benefit from CPAP therapy. A greater emphasis on adherence to CPAP and the combination of CPAP and weight loss are central to reducing cardiovascular risk among individuals with OSA.

Airway Analysis in Apert Syndrome

BACKGROUND

Apert syndrome is frequently combined with respiratory insufficiency, because of the midfacial deformity which, in turn, is influenced by the malformation of the skull base. Respiratory impairment resulting from Apert syndrome is caused by multilevel limitations in airway space. Therefore, this study evaluated the segmented nasopharyngeal and laryngopharyngeal anatomy to clarify subcranial anatomy in children with Apert syndrome and its relevance to clinical management.

METHODS

Twenty-seven patients (Apert syndrome, n = 10; control, n = 17) were included. All of the computed tomographic scans were obtained from the patients preoperatively, and no patient had confounding disease comorbidity. Computed tomographic scans were analyzed using Surgicase CMF. Craniometric data relating to the midface, airway, and subcranial structures were collected. Statistical significance was determined using t test analysis.

RESULTS

Although all of the nasal measurements were consistent with those of the controls, the nasion-to-posterior nasal spine, sphenethmoid-to-posterior nasal spine, sella-to-posterior nasal spine, and basion-to-posterior nasal spine distances were decreased 20 (p < 0.001), 23 (p = 0.001), 29 (p < 0.001), and 22 percent (p < 0.001), respectively. The distance between bilateral gonions and condylions was decreased 17 (p = 0.017) and 18 percent (p = 0.004), respectively. The pharyngeal airway volume was reduced by 40 percent (p = 0.01).

CONCLUSION

The airway compromise seen in patients with Apert syndrome is attributable more to the pharyngeal region than to the nasal cavity, with a gradually worsening trend from the anterior to the posterior airway, resulting in a significantly reduced volume in the hypopharynx.

Quantitative Morphometric Measurements of the Oropharynx in Obstructive Sleep Apnea Syndrome Using a Laser Depth Measurement Module

INTRODUCTION

Current diagnostic routines in obstructive sleep apnea syndrome (OSAS), including drug-induced sleep endoscopy (DISE), provide qualitative data. Quantitative morphometric measurements of oropharyngeal structures remain challenging. This study aims to introduce a special linear laser projection device that can facilitate computer-assisted digitalized analysis and provide important quantitative information for OSAS prediction.

MATERIALS AND METHODS

We used a single-wavelength green three-linear laser to provide the scaling reference, with one at an angle of 8.5 degrees with the other two which were parallel. The oropharyngeal images were divided into two groups: the non-OSAS and OSAS group, after polysomnography. A minimum of three evaluations were carried out to determine the maximum cross-sectional area of the oropharyngeal inlet (CSAOI) and the retropalatal depth.

RESULTS

A total of 132 subjects were enrolled in this study, with 76 subjects in the non-OSAS group and 56 cases in the OSAS group. In the non-OSAS group, the CSAOI was significantly larger in males than in females. There was a trend toward deeper retropalatal region in men than in women (14.25 vs 11.76 mm). Correlation analysis revealed that retropalatal depth is significantly related to body height and the CSAOI. The body weight and BMI of patients with OSAS were significantly higher than those of participants without OSAS. The retropalatal depth and CSAOI were significantly decreased in OSAS patients as compared to those without OSAS. Our new parameter, the oropharyngeal index, showed the most outstanding discrimination by ROC analysis to predict OSAS.

CONCLUSION

Our innovative module can provide reference parameters, which make it possible to directly estimate the objective absolute values of relevant oropharyngeal structures. Our non-invasive approach can be used for outpatient screening, since it allows the identification of potential OSAS patients who should be referred for polysomnography, as many patients do not require DISE early in their evaluation.

Adult obstructive sleep apnoea: Pathogenesis, importance, diagnosis and imaging

Obstructive sleep apnoea (OSA) is a serious worldwide health problem. Moderate-to-severe OSA has been found in up to 50% of men and 25% of women in the middle-aged population. It results in a fourfold increase in all causes of mortality. The prevalence of OSA is underestimated, partly due to absence of symptoms but also lack of knowledge amongst the population at large as well as sectors of the medical profession. Imaging, performed predominantly by clinicians and research scientists, has been integral to evaluating the anatomical basis of OSA. Increased nasal resistance and a narrowed and elongated oropharynx lead to increased collapsibility of the upper airway, predisposing to airway collapse and apnoea during sleep when there is reduction in tone of the pharyngeal dilator muscles. Unfortunately, a significantly narrowed upper airway is usually ignored by radiologists: it is not part of their reporting 'check-list'. The imaging findings in the upper airway that are strongly associated with OSA and its sequelae in various organ systems are discussed. Imaging can strongly suggest OSA; the diagnosis requires a polysomnogram for confirmation. Treatment of moderate-to-severe disease is primarily with positive airway pressure applied by a nasal or oral mask which splints the upper airway. Although highly effective, compliance is limited and other treatment modalities are increasingly being utilized.

The Role of Animal Models in Developing Pharmacotherapy for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a highly prevalent disease characterized by recurrent closure of the upper airway during sleep. It has a complex pathophysiology involving four main phenotypes. An abnormal upper airway anatomy is the key factor that predisposes to sleep-related collapse of the pharynx, but it may not be sufficient for OSA development. Non-anatomical traits, including (1) a compromised neuromuscular response of the upper airway to obstruction, (2) an unstable respiratory control (high loop gain), and (3) a low arousal threshold, predict the development of OSA in association with anatomical abnormalities. Current therapies for OSA, such as continuous positive airway pressure (CPAP) and oral appliances, have poor adherence or variable efficacy among patients. The search for novel therapeutic approaches for OSA, including pharmacological agents, has been pursued over the past years. New insights into OSA pharmacotherapy have been provided by preclinical studies, which highlight the importance of appropriate use of animal models of OSA, their applicability, and limitations. In the present review, we discuss potential pharmacological targets for OSA discovered using animal models.

Implantation of the nyxoah bilateral hypoglossal nerve stimulator for obstructive sleep apnea

Objectives

This report describes the surgical implantation of a novel bilateral hypoglossal nerve stimulator (Genio system®, Nyxoah S.A., Belgium) and the successful treatment of a patient with moderate obstructive sleep apnea (OSA).

Study Design

Surgical technique description and case study report.

Methods

The bilateral implantable stimulator (IS) simultaneously stimulates both genioglossus (GG) muscles to reduce airway obstruction. At night, patients wear an activation chip under their chin that wirelessly transmits energy to the implant and enables the nerve stimulation. Surgical implantation of the IS is performed under general anesthesia by making a small incision above the hyoid bone and dissecting through the platysma, mylohyoid, and geniohyoid muscles to the GG muscle. The hypoglossal nerve branches are then identified, followed by suturing the IS in place. The system was evaluated in an otherwise healthy, 60-year-old woman with moderate OSA (apnea hypopnea index (AHI): 25/hr, nadir O₂ saturation: 78%). Appropriate stimulation settings were determined at 2-, 3-, and 6-months post implantation during polysomnography (PSG) and changes in apnea and hypopnea events and oxygen desaturation recorded.

Results

The surgery was well tolerated by the patient with an uneventful recovery. The PSG at 6 months showed that AHI per hour, obstructive apnea events per hour, hypopnea events per hour, and oxygen desaturation index have been reduced by 88%, 92%, 88%, and 97%, respectively, and nadir O₂ saturation improved to 91%.

Conclusions

The absence of complications and considerable reduction of apnea and hypopnea events in this case study help demonstrate the potential safety and efficacy of the bilateral hypoglossal nerve stimulator.

Level of Evidence

4.

Relationship Between Nostril, Nasal Valve and Minimal Cross-Sectional Area in Functional Upper Airway

PURPOSE

To propose a three-dimensional cephalometric analysis of upper airway (UA) related to its functionality, defining normal reference values in healthy individuals and the relationship between nostril, nasal valve, and minimal cross-sectional area (MCS) in functional upper airway.

MATERIALS AND METHODS

The UAs of 20 Class I patients were analyzed with CBCT using Nemoceph 3D-OS and HOROS software, determining linear distances, volumes and cross-sectional areas, including MCS.

RESULTS

MCS was mostly located in the middle-upper oropharynx and high hypopharynx. MCS showed moderate correlation with the area of both nares (BNA) (r = 0.60, P = 0.004) and high correlation with the area of both internal nasal valves (BNV) (r = 0.66, P = 0.0016). BNA and BNV showed a moderate correlation (r = 0.445, P = 0.049). A total upper airway (TUA) and functional upper airway (FUA) volumes were established. TUA and FUA showed the strongest statistical correlation (r = 0.82, P = 0.00). A paired samples t test compared the measurement as absolute values of MCS with BNA (t = 0.781, P = 0.44), with BNV (t = -0.12, P = 0.90); and BNA with BNV (t = -0.76, P = 0.45), showed no significant differences.

CONCLUSIONS

A functional cephalometric analysis of the UA with stable parameters in cervical spine and normal reference values has been proposed. BNA and BNV could be used as reference to establish the MCS compatible with respiratory health.

Postural control abnormalities related to sleep deprivation in patients with Marfan Syndrome

BACKGROUND

Marfan syndrome (MFS) is a rare autosomal dominant connective tissue disorder affecting virtually every organ. Sleep disturbances, associated to high collapsibility in upper airways, are common in MFS; daytime sleepiness could lead to reduction in attention and motor coordination, with detrimental effects on balance.

OBJECTIVE

To evaluate otoneurological function in MFS patients, compared to healthy subjects, and to investigate possible correlations with sleep deprivation extent.

METHODS

Forty-one MFS patients underwent a thorough otoneurological examination, video Head Impulse Test (vHIT), and static posturography. Sleep parameters were recorded by home monitoring. Daytime sleepiness and dizziness-related handicap were screened by means of Dizziness Handicap Inventory (DHI) and Epworth Sleepiness Scale (ESS). Results were compared with 49 healthy controls (HC).

RESULTS

DHI and ESS scores were increased in MFS patients (p < 0,01). vHIT scores showed no between-group effect. Classical (surface and length) and frequency-domain posturographic parameters were significantly increased in MFS with respect to HC (p < 0,01). A positive correlation was found between ESS scores and posturographic parameters in MFS patients.

CONCLUSIONS

An impaired postural control, related to the extent of sleep deprivation, was found in MFS patients. Such results could advocate for screening and treating sleep deprivation and balance dysfunctions in MFS patients.

Critical Issues in Dental and Medical Management of Obstructive Sleep Apnea

This critical review focuses on obstructive sleep apnea (OSA) and its management from a dental medicine perspective. OSA is characterized by ≥10-s cessation of breathing (apnea) or reduction in airflow (hypopnea) ≥5 times per hour with a drop in oxygen and/or rise in carbon dioxide. It can be associated with sleepiness and fatigue, impaired mood and cognition, cardiometabolic complications, and risk for transportation and work accidents. Although sleep apnea is diagnosed by a sleep physician, its management is interdisciplinary. The dentist’s role includes 1) screening patients for OSA risk factors (e.g., retrognathia, high arched palate, enlarged tonsils or tongue, enlarged tori, high Mallampati score, poor sleep, supine sleep position, obesity, hypertension, morning headache or orofacial pain, bruxism); 2) referring to an appropriate health professional as indicated; and 3) providing oral appliance therapy followed by regular dental and sleep medical follow-up. In addition to the device features and provider expertise, anatomic, behavioral, demographic, and neurophysiologic characteristics can influence oral appliance effectiveness in managing OSA. Therefore, OSA treatment should be tailored to each patient individually. This review highlights some of the putative action mechanisms related to oral appliance effectiveness and proposes future research directions.

Effects of bicuspid extractions and incisor retraction on upper airway of Asian adults and late adolescents: A systematic review

OBJECTIVES

This systematic review aimed to assess the effects of bicuspid extractions and incisor retraction on airway dimension, hyoid position and breathing of adults and late adolescents.

METHODS

The review was conducted according to PRISMA guidelines. Eight databases including PubMed, EMBASE, Web of Science and Scopus were searched to August 2018. Minimum age of participants was 16 years. The intervention was dual-arch bicuspid extractions with incisor retraction. Outcomes were airway dimension, hyoid position and breathing assessment.

RESULTS

All nine publications meeting inclusion criteria were from Asia. They were divided into three Asian subregions. All East Asian lateral cephalometric studies reported anteroposterior airway narrowing at the oropharynx and sometimes the hypopharynx. However, the narrowing was small, comparable to measurement errors, and highly variable. Two out of three East Asian computed tomography (CT) studies described reductions in airway dimensions. The single functional breathing study showed increased simulated flow resistance after incisor retraction in East Asians. South Asian studies had mixed findings, with some reporting significant airway narrowing. The single study from West Asia found no significant airway or hyoid changes.

CONCLUSIONS

Airway response to bicuspid extractions and incisor retraction varied substantially when assessed with cephalometry. CT measurements present larger effect sizes and smaller variations, providing stronger evidence of airway narrowing. Orthodontic extractions for incisor retraction may be more frequently indicated in Asia, and East Asians seem particularly susceptible to airway narrowing and postero-inferior hyoid movement with incisor retraction. Better designed CT studies are needed for confirmation due to small effect size and large variability.

[Pathophysiology of obstructive sleep apnea]

The prevalence of obstructive sleep apnea (OSA) is considered to be very high in western industrialized countries. There are conservative and surgical forms of treatment for OSA; however, the pathophysiology is largely unexplained and cannot be explained by anatomical abnormalities alone. In recent years, a number of non-anatomical factors have been found that favor the development of OSA. These include the respiratory excitation threshold (arousals), the respiratory drive (loop gain), as well as the control and function of the muscular upper airway dilators. The understanding of the individual pathophysiological processes may be helpful in the future to develop individual treatment approaches for patients.

Oral appliance therapy in obstructive sleep apnea and snoring - systematic review and new directions of development

Objective: Oral appliance therapy is a non-invasive treatment that offers a wide variety of oral devices for the treatment of obstructive sleep apnea (OSA). The present review focuses on the effectiveness of mandibular advancement devices for the treatment of OSA. Methods: A systematic review based on the PRISMA checklist was carried out. A detailed electronic database search was conducted using "Obstructive sleep apnea" AND "Oral appliance" AND "Dentistry" as keywords. Results: The initial search in the electronic databases resulted in a total of 262 papers. After the title and abstract analysis and full-text review, the number of eligible papers was reduced to 15. Conclusion: The mandibular advancement device is an effective treatment, improving the Apnea Hypopnea Index and the symptoms of patients with OSA in 92% of the subjects from all the investigated studies. The future may include the integration of a biosensor for the diagnosis and follow-up. Abbreviations: OSA: Obstructive sleep apnea; MADs: Mandibular advancement devices; CPAP: Continuous positive airway pressure; OAT: Oral appliance therapy; MRD: Mandibular repositioning devices; MAS: Mandibular advancement splints; MAA: Mandibular advancement appliances; OA: Oral appliances; AASM: American Academy of Sleep Medicine; AHI: Apnea-hypopnea index; EEG: Sleep-related breathing disorder SRBD; Electroencephalogram; EOG: Electrooculogram; ECG: Electrocardiogram; QOL: Quality of life; TMJ: Temporomandibular joint.