RESUMO
BACKGROUND: The effectiveness of mandibular advancement devices has been solidly demonstrated in the past. They are considered a valid alternative treatment to continuous positive airway pressure for patients with obstructive sleep apnea. Nevertheless, the relationship between polysomnographic parameters and the increase in the volume of the upper airway in patients with obstructive sleep apnea syndrome has not been clearly established so far. This study aimed to determine the impact of these oral appliances upon the volume of the airway after the device titration phase and correlate it with the degree of mandibular advancement and the improvement of polysomnographic parameters. METHODS: All patients were diagnosed by polysomnography and were treated with a customized, titratable mandibular advancement device. Three-dimensional volumetric measurements were performed using cone beam computed tomography. RESULTS: The present study included 45 patients diagnosed with obstructive sleep apnea hypopnea syndrome (mild in 23 patients, moderate in 11 and severe in 11). Forty-four percent of the patients presented with an apnea hypopnea index <5/h at the end of treatment. The volume of the upper airway increased an average of 4.3 ± 5.9 cm3, this represents a percentage increase of 20.9%, which was significantly correlated with an apnea hypopnea index and a minimum oxygen saturation improvement. CONCLUSIONS: The mandibular advancement device used was found to be effective in improving polysomnographic parameters. Moreover, the oral appliance was able to significantly increase the tridimensional dimensions of the upper airway. Moreover, this finding was correlated with a reduction in the apnea hypopnea index (p = 0.007) and an increase on minimum oxygen saturation (p = 0.033).
RESUMO
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.
