Chin tuck or chin "collapse"?

[Bassline]

(Continuation of my previous thread Altitude, dehydration, and centrals - but changing focus a bit. Mods: please move it back under if it should be in the same thread. BTW, a big thanks to all who contributed to that topic. I passed the info along to my PCP, who apparently has a different patient who has been fighting unresolved CPAP issues long-enough that she has been considering moving out of region to lower elevations. Hopefully this helps her as well, or at least motivates her to come to the forum.)

TL;DR version: does the cluster on the attached screenshots look like it's due to chin tuck or due to chin "collapse" caused by the full face mask pressing the jaw into the airway?

Longer version: after playing with the max pressure to balance between mouth leak arousals and apnea events, I determined that there was no "good lower pressure" for me that really made much difference in how I felt the next morning. I then just set the max back up to 18, and am now trying to address the leaks directly. (Many of these are definitely mouth leaks, with a couple of recent nights having me waking up with a dry, open mouth.) Increasing the humidity has helped some, but really hasn't fully solved the problem.

With all of the periodic breathing and related centrals pretty-much addressed now, and no longer masking other issues, I wondered if giving the AirTouch F20 another chance will help me better deal with the mouth leaks. The attached screenshots are the result of the first night back on the F20, same chin strap and pressure settings as before with the P10.

The leaks are almost completely gone (yay), but at the cost of double the AHIs and increased aerophagia - neither of which were helped by an event cluster and related spike in pressure. Looking at how the obstructions don't seem to be impacted by even close-to-max pressure on the machine, this seems to me that this might be a positional issue. However, I wonder if this is due to chin tuck or due to the jaw collapsing into the airway. (I recall that the AirTouch F20 is supposed to be worn more tightly than the AirFit F20 in order to seal properly.)

Thoughts? I'm trying to avoid buying yet another SCC unless I need to continue down that path.

       

[Sleeprider]

I think we have a habit of calling positional apnea what it is without much regard for its cause, so your question whether this is mask related or chin tucking is good food for thought. If the mask pulls the jaw back it will increase potential for airway restriction. A soft cervical collar or chinstrap like the one offered by Supplier #37 would likely help. The mechanism of obstruction is basically the same, and forward pressure on the jaw from a SCC or upward pull from a well designed jaw strap can help overcome that rearward pull by a mask or the wrong style of chinstrap. Maybe check into the Knightsbridge double chin strap?

[Bassline]

Answer to my question ... "still hard to say exactly". I had a feeling that the latest chinstrap (a copy of the Respironics Deluxe) was causing issues: the elastic is much more stiff than the previous one, causing it to be less effective at holding the jaw forward without really "cranking it down" ... which then often caused it to shift the jaw back instead, not to mention a painful flattening of my ears.

I ended up replacing it with (yet another) SCC - Velpeau "Dual Use". I added some mouth tape again as well.


So far, it's been a rare night with numbers above 2 AHI, and during the first couple of weeks I was getting nights consistently below 1. Progress is good.   

Lately, I've been finding the SCC doesn't quite hold its position as well when I'm on my side, and that it sometimes loosens enough that I need to tighten it back up sometime during the night. I wonder if others have noticed this problem, and if so if they have a solution. (Doesn't appear to be the velcro, since that's pretty new.) I wonder if the foam gets warm and compresses during the first part of the night.

[Sleeprider]

It's good to hear you have had good success treating the positional OA with the Velpeau dual use. I had to look it up and see that model has a removable plastic support plate.

Velpeau Neck Braces have three designs, comfort version, dual-use and enhanced version.The comfort version is soft and comfortable. For the dual-use version, the external flexible plastic support plate that can be removed freely is added to improve the support force. If the support plate is removed, the effect is the same as the comfort one. The enhanced version is made of double layer foam and EVA foam superimposed on each other, which is soft and provides more powerful support.

[Bassline]

It's good to hear you have had good success treating the positional OA with the Velpeau dual use.  I had to look it up and see that model has a removable plastic support plate.  

I got the reference to this SCC line from edfreeman, and ran with it.

To me, one key factor with this particular model is that the stiffening plate only wraps around the front and sides of the collar. A big part of my problem with previous SCCs was too much material pressing against the back of my neck, and rigid foam pressing into my jaw when I was lying on my side. 

With this model, in theory you'd get the higher rigidity of a stiffer collar in front and sides, softer and less material against back of the neck, and a layer softer padding material where it hits the chin and jaw - kind of an amalgam of the broader support of the stiffer foam SCCs, the softer jawline interface of the Releaf, and the minimized rear bulk of a Dr. Dakota / Eliminator. (Since I'm at the upper end of the size range for mine, I get even less rear bulk at the back.)

That's the theory at least. I'm still figuring out the proper tightness level to use that works through the night.

[Sleeprider]

I would appreciate a review in the review forum if you have a chance. We have a lot of members using the SCC but very few have taken the time to share their experience as a review. It really helps those that need one to see the pros and cons of different models.

[Bassline]

Will do - I'd like to get about a week more experience with it before I give it a review.

[DaveL]

Interesting thread!
I returned to using my cpap cap this week with poor results. I've ordered replacement parts for my N20 mask in case that will help.

During covid19 I tried buying a curvical collar from amazon. That didn't work! and I had to go into the drug store/post office to send it back. (Not happy!)

I find the Knightsbridge double chin strap interesting. And it looks like it won't be too hot to wear at night.