Hyoid slump hypothesis: A rational approach to understanding obstructive sleep apnea and related airway disorders

Abstract

Obstructive sleep apnea (OSA) significantly affects health; however, its pathogenesis remains unclear. We propose the Hyoid Slump Hypothesis, which identifies the caudal displacement (“slump”) of the hyoid bone as a central etiological factor underlying OSA. Traditional models emphasize obesity and soft tissue redundancy in adults. In contrast, adenotonsillar hypertrophy is typically the primary cause of upper airway obstruction in children, although soft tissue factors become increasingly relevant with age and obesity. Accumulating evidence indicates that craniofacial development and neuromuscular function are critical for maintaining airway patency. Poor oral posture and dysfunctional breathing predispose individuals to a lower hyoid position, thereby reducing airway stability. Cephalometric radiography studies have consistently linked an increased mandibular plane-to-hyoid (MP-H) distance to OSA severity. Dynamic imaging methods have demonstrated significantly inferior hyoid displacement during airway collapse events. Therapeutic interventions targeting hyoid elevation, such as mandibular advancement, orthopedic maxillary expansion, hyoid suspension and myofunctional therapy, provide additional support. Despite promising evidence, limitations include reliance on observational data, lack of standardized measurement protocols, and the multifactorial nature of OSA. Prospective studies are needed to clarify causality, refine diagnostics, and guide individualized interventions. Confirmation of this hypothesis would enhance diagnostic precision, support early preventive strategies in childhood, and allow targeted therapeutic approaches tailored to the distinct anatomical phenotypes of airway obstruction.