Aim: To investigate whether obstructive sleep apnea (OSA) patients present different behaviors of mandible
movements before and under CPAP therapy.
Materials and Methodology: In this retrospective study, patients were selected according to inclusion criteria: both the diagnostic
polysomnography recording showing an OSA with an apnea-hypopnea index (AHI) greater than 25 (n/h) and the
related CPAP therapy control recordings were available, presence of mandible movement and mask pressure signals in the
recordings, and tolerance to the applied positive pressure. Statistical analysis on four parameters, namely the apneahypopnea
index (AHI), the arousal index (ArI), the average of the mandible lowering during sleep (aLOW), and the average
amplitude of the oscillations of the mandible movement signal (aAMPL), was performed on two sets of recordings:
OSA and CPAP therapy.
Results: Thirty-four patients satisfied the inclusion criteria, thus both OSA and CPAP groups included thirty-four recordings
each. Significant difference (p < 0.001) was found in the OSA group compared with the CPAP group when considering
either the four parameters or only the two ones related to mandible movements.
Conclusions: When an efficient CPAP pressure is applied, the mouth is less open and presents fewer broad sharp closure
movements, and oscillating mandible movements are absent or very small.