Comparison of drug-induced sleep endoscopy and upper airway computed tomography in obstructive sleep apnea patients

The use of CBCT in orthodontics with special focus on upper airway analysis in patients with sleep-disordered breathing

Applications of cone-beam CT (CBCT) in orthodontics have been increasingly discussed and evaluated in science and practice over the last two decades. The present work provides a comprehensive summary of current consolidated practice guidelines, cutting-edge innovative applications, and future outlooks about potential use of CBCT in orthodontics with a special focus on upper airway analysis in patients with sleep-disordered breathing. The present scoping review reveals that clinical applications of CBCT in orthodontics are broadly supported by evidence for the diagnosis of dental anomalies, temporomandibular joint disorders, and craniofacial malformations. On the other hand, CBCT imaging for upper airway analysis-including soft tissue diagnosis and airway morphology-needs further validation in order to provide better understanding regarding which diagnostic questions it can be expected to answer. Internationally recognized guidelines for CBCT use in orthodontics are existent, and similar ones should be developed to provide clear indications about the appropriate use of CBCT for upper airway assessment, including a list of specific clinical questions justifying its prescription.

A Novel Method to Classify the Responses of Genioglossus to Negative Pressure in OSA Patients

OBJECTIVE

This study aims to develop a novel method to classify different genioglossus (GG) responses to upper airway (UA) negative pressure in obstructive sleep apnea (OSA) patients.

STUDY DESIGN

A single-center, prospective, cohort study.

SETTING

Sleep Medical Center.

METHODS

Patients with OSA underwent drug-induced sleep endoscopy with synchronous genioglossus electromyography (ggEMG) and UA pressure monitoring. In spontaneous obstructive apnea events, the value of epiglottis negative pressure at the end of inspiration (Pepi ) and corresponding peak phasic ggEMG were recorded as pairing data for linear regression analysis to classify GG response modes: peak phasic ggEMG-Pepi linear mode (P < .05) were classified as group 1; others (P ≥ .05) were classified as group 2. Using nasopharyngeal tube (NPT) to reopen the palatopharyngeal cavity for comparing the improvement between the OSA patients with different GG response modes.

RESULTS

Sixty subjects were analyzed for GG response modes: 22 patients were in group 1 (r2  = 0.233-0.867), and 38 patients were in group 2. The proportion of partial (63.16% vs 59.09%) or complete (36.84% vs 22.73%) collapse rate of the tongue base in group 2 was significantly higher (χ2  = 7.823, P = .020). The improvement of the apnea-hypopnea index after NPT placement in group 2 was significantly lower than in group 1 (59.09% vs 31.58%, χ2  = 4.339, P = .037).

CONCLUSION

This novel method is advantageous for distinguishing OSA patients with different GG response abilities to UA negative pressure, whose GG responses conforming to peak phasic ggEMG-Pepi linear mode might be more suitable for palatopharyngeal surgery.

Characteristics and Mechanism of Upper Airway Collapse Revealed by Dynamic MRI During Natural Sleep in Patients with Severe Obstructive Sleep Apnea

Purpose

Upper airway collapse during sleep in patients with obstructive sleep apnea (OSA) is a complex and dynamic phenomenon. By observing and analyzing the dynamic changes in the upper airway and its surrounding tissues during airway obstruction, we aim to reveal dynamic characteristics in different obstruction patterns, and the relationship between anatomical features during normal breathing and dynamic characteristics of airway obstruction.

Patients and Methods

Dynamic MRI was performed in 23 male patients (age range 26-63) with severe OSA diagnosed by overnight polysomnography, and obstruction events were identified from their images. Dynamic changes in parameters of the upper airway and surrounding tissues were measured to assess the key characteristics in different obstruction patterns.

Results

We categorized airway obstruction into four types based on the obstruction location and motion characteristics of tissues during collapse, and detailed the alterations in the airway and surrounding tissues under each obstruction pattern. In all 112 obstruction events extracted from the dynamic images of 23 patients, type A (retropalatal obstruction caused by the soft palate separated from the tongue), BI, BII (both retropalatal obstructions caused by the soft palate attached to the tongue, and C (retropalatal and retroglossal obstruction caused by the soft palate and the tongue), accounted for 28.6%, 44.6%, 12.5%, and 14.3% respectively. In severe OSA patients with tongue and palatal obstruction related to type B or C, the more posterior hyoid position, shorter distance between tongue and uvula, and wider retropalatal space, the larger the tongue displacement and deformation during collapse, and the greater the reduction in airway space.

Conclusion

There are multiple airway obstruction patterns, each with its own anatomical characteristics and behaviors during collapse. Hyoid position, tongue and uvula distance, and retropalatal space play an important role in airway collapse and should be paid more attention in the treatment of OSA.

Computed Tomography versus Sleep Endoscopy (DISE) to Predict the Effectiveness of Mandibular Advancement Devices in Adult Patients with Obstructive Sleep Apnea: A Protocol for Systematic Review

Obstructive sleep apnea is a sleep disorder with a high prevalence in the world population. The mandibular advancement device is one of the options for treating obstructive sleep apnea. Neck computed tomography and drug-induced sleep endoscopy are complementary diagnostic tests that may help predict the effectiveness of mandibular advancement devices. This study aims to analyze the best method for predicting the effectiveness of mandibular advancement devices in the therapeutic approach to obstructive sleep apnea. PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science Core Collection databases will be comprehensively searched. We will include randomized clinical trials, non-randomized prospective or retrospective clinical studies, case controls, cohort studies, and case series. Two authors will independently conduct data extraction and assess the literature quality of the studies. The analysis of the included literature will be conducted by Revman 5.3 software. The outcomes that will be analyzed are craniofacial characteristics, cephalometric assessments, site and type of obstruction of the upper airway, mean values of the apnea-hypopnea index, and SaO2 verified in the initial and follow-up polysomnography. This study will provide reliable, evidence-based support for the clinical application of mandibular advancement devices for obstructive sleep apnea.

Evaluation of Upper Airway in Children with Obstructive Sleep Apnea Using Cone-Beam Computed Tomography

OBJECTIVE

Cone-beam computed tomography (CBCT) offers three-dimensional structures in assessing upper airway of patients. This study aims to compare the cone-beam computerized tomography scan measurements between children with obstructive sleep apnea (OSA) and primary snoring.

STUDY DESIGN

Case-control study.

METHODS

This prospective study was conducted in a tertiary referral center. Thirty-six children with moderate-to-severe OSA (with apnea-hypopnea index [AHI] > 5 events/hour) and 36 age-, gender-, and obesity-matched children with primary snoring (AHI <1) were enrolled. The measurements in CBCT parameters were compared between children with moderate-to-severe OSA and primary snorers by conditional logistic regression model.

RESULTS

A total of 72 children (mean age, 7.9 ± 2.8 years; 64% male) were included. Children with moderate-to-severe OSA had a significantly smaller nasopharyngeal (2900 ± 1400 vs. 3800 ± 1800 mm³ , P = .017) and oropharyngeal airway volume (5600 ± 2700 vs. 7400 ± 4000 mm³ , P = .026) than those with primary snoring. Children with moderate-to-severe OSA, as compared to primary snorers, also had a significantly smaller minimal airway area in nasopharynx (77.4 ± 37.7 vs. 107.7 ± 52.0 mm² , P = .006) and oropharynx (66.6 ± 61.9 vs. 101.6 ± 65.8 mm² , P = .023). Moreover, the airway length was not significantly different between children with moderate-to-severe OSA and primary snoring.

CONCLUSIONS

The three-dimensional CBCT airway analysis could be used as a useful tool to evaluate upper airway in children with OSA.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:680-685, 2021.

Fibronasolaringoscopia en el diagnóstico de síndrome de apnea-hipopnea obstructiva del sueño (SAHOS)

En los pacientes con diagnóstico de trastornos respiratorios del sueño (TRS) no se ha podido asociar ningún hallazgo anatómico a la severidad de la patología que el paciente presenta o a su éxito quirúrgico. Los avances actuales en la tecnología de video han permitido evaluar de manera más fidedigna las medidas de la vía aérea (VA) y trazar un mapa más exacto del sitio específico de obstrucción. La fibronasolaringoscopia es una técnica accesible y económica para la evaluación de la VA en múltiples posiciones en períodos de sueño y vigilia; esta requiere un amplio conocimiento por parte del examinador de la anatomía y fisiología de la vía aérea superior para determinar los sitios exactos de obstrucción y los patrones de colapso que podrían determinar la posibilidad del manejo quirúrgico o no, haciendo de este examen diagnóstico parte fundamental en el estudio de los pacientes con TRS.