Cephalometric, muscular and swallowing changes in patients with OSAS

Obstructive Sleep Apnoea Syndrome (OSAS) is believed to be associated with craniofacial and neuromuscular changes, although the interplay among these variables still is poorly recognised. The objective of this study was to identify hyoid, muscular and swallowing changes associated with OSAS, and to correlate these alterations with OSAS severity. Cross-sectional study, in a tertiary referral centre. Seventy-two adult individuals participated in this study: 12 controls (without apnoea) and 60 patients with apnoea (mild, moderate and severe OSAS-20 individuals in each group). All participants were initially evaluated by otorhinolaryngologist and neurologist and underwent polysomnography for OSAS stratification. Cephalometric data, clinical myofunctional status and swallow videofluoroscopy exam were assessed. A hybrid effect model was used to analyse swallowing parameters; dependent variables were age, body mass index (BMI) and cephalometric measures. Individuals with OSAS presented lower hyoid position and narrower posterior airway distance when compared to controls. These parameters correlated to OSAS severity. Additionally, OSAS patients exhibited significantly lower myofunctional scores. Both velum and hyoid contraction times were significantly lower in the OSAS group at videofluoroscopy, regardless of its severity. Premature leakage into pharynx was more common in OSAS groups. Laryngeal penetration phenomenon occurred only in two patients (both from OSAS group). Our results suggest that hyoid bone position is associated with OSAS severity. Muscular pattern and swallowing are impaired in OSAS patients, irrespective of OSAS severity and facial profile. These findings indicate a higher predisposition of OSAS patients to present an inferior hyoid positioning, accompanied by myofunctional and swallowing disorders.