The Role of the Hyoid Bone in Obstructive Sleep Apnea Severity: A Systematic Review

Obstructive sleep apnea (OSA) has numerous complications that negatively impact patients' quality of life. Early diagnosis can significantly reduce these complications. The aim of the study was to evaluate the relationship between the hyoid bone position and the severity of apnea, and to determine if hyoid-related cephalometric variables can be used as predictors of apnea severity. A systematic review of the literature was conducted following PRISMA guidelines. The search was conducted across databases including Medline, ScienceDirect, BVS, and WOK. Two researchers analysed the results applying inclusion and exclusion criteria, with a third researcher resolving discrepancies. After screening, a total of 22 articles were selected for qualitative review. The risk of bias and quality of the studies was assessed using the Downs and Black checklist. Among the 22 selected articles, 9% were classified as poor quality, 46% as fair, and 45% as good quality. A positive correlation was observed between a lower hyoid bone position and the apnea-hypopnea index (AHI), indicating that a lower hyoid position is associated with a higher AHI. The H-MP variable (distance between point H and the mandibular plane) presented the strongest predictive power for OSA severity. However, insufficient evidence was found to establish an association between the anteroposterior position of the hyoid bone and OSA severity. The severity of obstructive sleep apnea (OSA) is associated with a lower position of the hyoid bone, as reflected in the positive correlation between H-MP and the apnea-hypopnea index (AHI), while the sagittal position showed no significant relevance.