Use of a face mask in the measurement of resting ventilatory parameters and mouth occlusion pressures.

A recent study has suggested that mouth occlusion pressure (MOP) could be measured during sleep by using a face mask. The purpose of the present study was to examine the effects of a face mask on MOP and resting ventilatory parameters (RVP). Measurements of MOP and RVP were made by three different methods; while breathing through a mouthpiece with nose-clip (MP+NC), through a face mask breathing through the mouth only (FM/mouth), and through a face mask breathing through the nose only (FM/nose). There was a significant difference in several RVP parameters between MP+NC and FM, but no significant difference in MOP between different methods. Use of FM for the measurement of MOP appears to be warranted, and with regard to RVP consideration needs to be given to the differences found between MP+NC and FM.