An animal model of obstructive sleep apnoea-hypopnea syndrome corrected by mandibular advancement device

The aim of the study is to establish a stable animal model of obstructive sleep apnoea-hypopnea syndrome (OSAHS) and assess the effectiveness of a mandibular advancement device (MAD).

Eighteen 6-month-old male New Zealand white rabbits were randomized into three groups according to intervention: Group OSAHS, Group MAD, and a control group (n = 6 for each group). Rabbits in Group OSAHS and Group MAD were established as OSAHS model by injection, at a dose of 2 ml hydrophilic polyacrylamide gel, in the submucous muscular layer of the soft palate. Computed tomography (CT) and polysomnography (PSG) showed that OSAHS was developed successfully, the rabbits in Group MAD were fitted with the MAD and CT of the upper airway and PSG evaluated its effectiveness. Histological observation of the injection sites was conducted.

CT scans showed the reduced sagittal space and cross-sectional areas of retropalatal upper airway in Group OSAHS were corrected by MAD (upper airway space in Group MAD was similar to that in the control group). The rabbits in Group OSAHS developed obvious sleep apnoea and hypopnea in supine position, with increased apnoea-hypopnea index and decreased oxygen saturation (SaO2). These were significantly improved by MAD and apnoea and hypopnea were not observed. Histology of the soft palate showed that the injected gel was entirely surrounded with connective tissues.

We primarily developed an OSAHS and MAD therapy animal model with narrow oropharynx in upper airway which could be further available for OSAHS analysis.