Use of oral appliance in treatment of obstructive sleep apnoea: Hong Kong experience

Abstract

Purpose: The role of oral appliance (OA) in the treatment of obstructive sleep apnoea (OSA) has been investigated and reported with variable success in several Caucasian studies. However, mandibular cervical anatomy varies with ethnicity, hence the efficacy of such appliances may also differ. Methods: We prospectively evaluated the role of mandibular advancing device in the treatment of Chinese patients with symptomatic mild to moderate OSA. Consecutive patients were recruited if the following criteria were fulfilled: Apnoea-hypopnoea index (AHI) 10-20 plus nocturnal choking or excessive daytime sleepiness (ESS = 9 or above), AHI 20-40, and AHI>40 but refused to use nCPAP. Parameters analysed include demographic, polysomnographic, and cephalometric data (supine CT of the upper airway). Efficacy, compliance, and side effects were evaluated by in-patient sleep study (2 months after using OA) and a questionnaire (2 and 6 months after using OA). Results: 13 patients (10 M, 3F) have been recruited with mean age of 51.2 yrs. The mean BMI was 26.1 and 26.2 at baseline and reassessment respectively. All patients have subjective (ESS) and objective (AHI) improvement. The mean ESS decreased from 11.6 to 5.5. The mean AHI decreased from 21.2 to 5.5, and the mean arousal index decreased from 23 to 10.6. Change in sleep stage were observed, more slow wave sleep and more REM sleep after using OA while the sleep efficiency remained the same. The mean mandible-hyoid bone distance decreased from 23.1 to 16.1 cm while the posterior airway space remains essentially the same (7.2 → 7.5 cm). The average time of using OA was 6.2 nights/week. 3 patients had dryness of throat, 2 had toothache, 2 had tooth discomfort and 6 had no complaint after using OA. Conclusions: In this preliminary analysis, we show that OA is a simple and effective treatment in Chinese patients with mild-moderate OSA. It has little side effects and a good compliance in the short term evaluation. Clinical Implications: Oral appliance may be useful in the treatment of mild-moderate OSA. Predictive factors guiding its success should be explored.