I use a ResMed AirCurve 10 VAuto machine with a ResMed AirFit P10 nasal pillow and chin strap. Last night I unintentionally pulled the chin strap off my head because the combination of my chin strap and nasal pillow strap were causing me some localized pain. This is a very rare occurrence, so I'm not too concerned about the pain, nor about removing my chin strap. What did surprise me, however, was the fact that my machine indicated a normal "Mask Seal" (a green smiley face, as opposed to the red frown face) upon waking. This surprised me because I know that, in previous experiences, removing my chin strap resulted in mouth breathing and large leaks. It's possible that, after 2 years of CPAP and BiPAP use with a chin strap, I've become accustomed to sleeping with my mouth closed, but I'm uncertain about this.
I thought that I would download SleepHead and view the data. I found that on several nights within the past 2 weeks the Max Leak rate was well over 24 L/min (near 50 L/min), the 95% Leak Rate was also over 24 L/min (near 35 L/min), and the Med Leak Rate was well under 24 L/min (near 5 L/min), even though I was wearing a chin strap. According to the SleepHead Wiki, these data could suggest that leaks are a serious problem for me. Yet, my AHI is consistently (with extremely rare exceptions) well below 5. I assume that these trends can be generalized to larger periods of time and therefore I'd like to determine whether they suggest that my therapy is being compromised. I suppose that this may depend upon the frequency and duration of the leaks.
Can someone help me to ascertain whether these data suggest that leaks are a serious problem and, if so, why my machine might be detecting a normal "mask seal"? Furthermore, are there better ways to view my data so that I can determine the effect that leaks are having on my therapy? Thank you very much for your assistance!