Mandibular Advancement Device Improves the Function of Hypoglossal Nerve in OSA Rabbits.

BACKGROUND

This study investigates the interaction between the motor endplate of the genioglossus and the hypoglossal nerve in an obstructive sleep apnea (OSA) model and explores the mechanism of mandibular advancement devices (MAD) in treating OSA.

METHODS

18 male New Zealand white rabbits were randomly divided into three groups-control, OSA and MAD (n = 6 each). OSA was induced in the OSA and MAD groups by injecting gel into the soft palate. The MAD group received MAD treatment. Cone-beam computed tomography (CBCT) and polysomnography (PSG) confirmed MAD efficacy. Rabbits underwent 2 h of sleep induction daily for 8 weeks. Electrophysiological signals of the genioglossus and hypoglossal nerve were recorded. Morphological assessments of nerve fibres and motor endplates used gold chloride, acetylcholine and haematoxylin-Eosin (HE) staining. Immunofluorescence and acetylcholinesterase (AChE) staining evaluated nerve conduction.

RESULTS

OSA symptoms were successfully induced and reversed by MAD. Structural and functional impairments of the hypoglossal nerve and motor endplates in the OSA group were alleviated by MAD, improving nerve impulse conduction and muscle function.

CONCLUSIONS

MAD treatment mitigates OSA-induced damage to the hypoglossal nerve and genioglossus motor endplates, enhancing structure and function.