Multislice Computed Tomography Assessment of Airway Patency Changes Associated with Mandibular Advancement Appliance Therapy in Supine Patients with Obstructive Sleep Apnea

Dimensional analysis of the upper airway in obstructive sleep apnoea syndrome patients treated with mandibular advancement device: A bi- and three-dimensional evaluation

BACKGROUND

The efficiency of the mandibular advancement device (MAD) in patients with obstructive sleep apnoea syndrome (OSAS) has been demonstrated. Nevertheless, the behaviour of the upper airway once MAD is placed and titrated, and its correlation with the apnoea-hypopnoea index (AHI) is still under discussion.

OBJECTIVES

To analyse the morphological changes of the upper airway through a bi- and three-dimensional study and correlate it with the polysomnographic variable, AHI.

METHODS

Patients were recruited from two different hospitals for the treatment of OSAS with a custom-made MAD. A cone-beam computer tomography and a polysomnography were performed at baseline and once the MAD was titrated.

RESULTS

A total of 41 patients completed the study. Treatment with MAD reduced the AHI from 22.5 ± 16.8 to 9.2 ± 11.6 (p ≤ .05). There was a significant increase of the total airway volume with MAD from 21.83 ± 7.05 cm³ to 24.19 ± 8.19 cm³ , at the expense of the oropharynx. Moreover, the correlation between the improvement of the AHI and the augmentation of the volume of the upper airway was not statistically significant.

CONCLUSIONS

The oral device used in this prospective study increased the mean upper pharyngeal airway volume and significantly reduced the AHI. Future studies that measure the muscular tone are needed to completely understand the association between the AHI and the physiological and anatomical response of the upper airway.

Upper airway volumetric changes of obstructive sleep apnoea patients treated with oral appliances: a systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnoea (OSA) is a common sleep-related breathing disorder, attributed to the collapse of the pharyngeal walls and the subsequent complete or partial upper airway obstruction. Among different treatment options for OSA, Continuous Positive Airway Pressure, and oral appliances (OAs) have been used, with various outcomes and side effects.

OBJECTIVE

The aim of this study was to summarize current knowledge in an evidence-based manner regarding the upper airway volume increase of OSA patients while treated with OAs.

SEARCH METHODS

Electronic search was conducted in Pubmed, Cochrane Library, and Scopus, up to May 2020.

SELECTION CRITERIA

Studies were selected after the application of predetermined eligibility criteria.

DATA COLLECTION AND ANALYSIS

Mean airway volume differences and the corresponding 95% confidence intervals were calculated, using the random effects model. Sensitivity, exploratory, and meta-regression analyses were also implemented.

RESULTS

Eleven studies filled the inclusion criteria and were included in the systematic review, while 10 of them were suitable for meta-analysis. In total, 291 patients were included, with mean upper airway volume increase of 1.95 cm3 (95% CI, 1.37-2.53; P < 0.001) with Mandibular Advancement Devices in place. In all studies, post-treatment Apnea Hypopnea Index (AHI) was either <10 events/hour or was reduced by more than 50% from baseline levels. A greater increase of the velopharynx volume was observed, regarding airway compartments.

CONCLUSIONS

Treatment with OAs in OSA may lead to a significant increase of the upper airway volume with a subsequent decrease of AHI. The velopharynx seems to be affected the most from OA therapy.