Sleeping tongue: current perspectives of genioglossus control in healthy individuals and patients with obstructive sleep apnea

Abstract

The focus of this review was on the genioglossus (GG) muscle and its role in maintaining upper airway patency in both healthy individuals and obstructive sleep apnea (OSA) patients. This review provided an overview of GG anatomy and GG control and function during both wakefulness and sleep in healthy individuals and in those with OSA. We reviewed evidence for the role of the GG in OSA pathogenesis and also highlighted abnormalities in GG morphology, responsiveness, tissue movement patterns and neurogenic control that may contribute to or result from OSA. We summarized the different methods for improving GG function and/or activity in OSA and their efficacy. In addition, we discussed the possibility that assessing the synergistic activation of multiple upper airway dilator muscles may provide greater insight into upper airway function and OSA pathogenesis, rather than assessing the GG in isolation.

Keywords: airway collapsibility and sleep; airway obstruction; pharyngeal dilators; upper airway.

Figure 1

Schematic figure representing the major inputs (central pattern generator, chemoreceptor, mechanoreceptor and sleep–wake state) to the GG via the hypoglossal nerve (labeled XII). Notes: IP/IT refers to inspiratory phasic or inspiratory tonic units that are located primarily in the posterior segment of the GG. EP/ET refers to expiratory phasic or expiratory tonic units that are located primarily in the anterior segment of the GG. Abbreviation: GG, genioglossus.