[Efficacies of using modified oral appliance after uvulopalatopharyngoplasty in the treatment of moderate to severe obstructive sleep apnea hypopnea syndrome].

OBJECTIVE

To evaluate the efficacies of a modified oral appliance (MOA) for residual obstruction after uvulopalatopharyngoplasty (UPPP) in the treatment of moderate-to-severe obstructive sleep apnea hypopnea syndrome (OSAHS).

METHODS

The patients with residual airway obstruction on polysomnography (PSG) at four weeks post-UPPP were selected from the Sleep Medicine Center, Gansu Provincial People's Hospital from October 2013 to February 2014. As of week 5 post-UPPP, all subjects wore MOA for 4 weeks. Before and 4 weeks after treatment, questionnaires were distributed to evaluated the improvement of subjective and objective sleep. The average apnea hyponea index (AHI) and sleep patterns were examined by PSG. The sagittal diameter in minimal region of retropalatal and retroglossal patency and the volume of orophary were measured by cone beam computed tomography (CBCT) scans. And the correlation between the outcomes of CBCT and AHI were analyzed.

RESULTS

A total of 10 male OSAHS patients were enrolled. The average age was (42.4 ± 9.2) (31-55) years, body mass index (BMI) (25.0 ± 4.8) (22.8-29.4) kg/m² and AHI was (26.0 ± 7.5) (15.8-35.9)/h. After wearing MOA for 4 weeks, the symptoms of snoring, daytime somnolence and suffocated waking during sleep improved as compared with that pre-treatment. All adapted to sleep with MOA. Average AHI decreased from (26.0 ± 7.5)/h to (6.0 ± 0.7)/h (P < 0.001). And the lowest average oxygen saturation value (SaO₂) increased from (79.6 ± 3.9)% to (87.6 ± 1.6)% (P < 0.001). PSG indicated that the percentage of awakening time and sleep time in nonrapid eye movement (NREM) stage 1 decreased from (11.0 ± 2.3)% and (26.1 ± 4.3)% to (6.8 ± 1.6)% and (11.1 ± 1.5)% respectively in total sleep time (TST). The percentage of NREM stage3 sleep time and rapid eye movement (REM) sleep time in TST increased on average from (10.2 ± 2.2)% and (11.6 ± 1.4)% to (17.7 ± 3.1)% and (21.3 ± 3.1)% respectively (all P < 0.001). CBCT measurements showed that the sagittal diameter in minimal region of retropalatal and retroglossal patency increased on average by (0.64 ± 0.04) and (1.51 ± 0.18) mm respectively. The average volume of orophary increased by (2 446 ± 963) mm³ (all P < 0.05). Negative correlations existed between AHI and sagittal diameter of minimal region of retroglossal patency, AHI and volume of orophary (all P < 0.05).

CONCLUSION

The application of MOA after UPPP can significantly increase the sagittal diameter of minimal region of retroglossal patency and the volume of orophary and improve effectively hyperpnoea and disordered sleep patterns.