STILL trying to make sure what mask size!!

I was given a large UMFF mask at start. Decided too much leaks and seemed to be a little too big. Borrowed the UMFF medium (both standard) and thought I would know for sure which is best.. Well did not work out that easy. I do think it should be the medium as my eye to below lower lip fits that closer. Also, in the mask sizing info says to get a mask that most closely comes to edge of mouth which the medium is better.
To try to quantify my subjective feelings and after I read a snoredog post that showed how to reset the screen (not the card) I decided to do a nightly test switching back and forth one night the large ad one night the medium. I have at least one more night (may do it two more nights to that to get 3 nights with each mask but on this info can anyone determine what the machine is stating?

medium night 1
90% = 12.4
system leak = 10.3
AHI = 2.0

medium night 2
90% = 10.0
system leak = 32.8
AHI = 2.6



large night 1
90% = 9.5
system leak = 24.0
AHI = 2.5

tonight will be the second night for large I will update this info. Side comments are last night (night 2 on medium) I seemed to have more itches that I would lift mask a second to scratch could that of tossed the system leak up like it did? The medium seems to just be abetter fit in the feel as the large seems to have more space under my mouth and the sides any comments? I do not need to make a decision until Tuesday (actually 2 weeks after that) but I would like to get the mask size past and on to other concerns <g>
thanks

I should add that the medium seems to give me a better seal at the nose bridge area. Does that make sense? If any of you read my previous poss about mask size you might remember my confusion is caused somewhat by the doctor office. When i had the titration study done the tech measured me and said you need a medium standard .. When i went to pick up the equipment the day tech/nurse of the doctor's office went thru the equipment etc she said she was out of the medium BUT had large in stock and proceeded to measure me and said a large SHOULD be fine. She did say I could swap for a new medium within 30 days no charge BUT I still wonder if her "large" should be fine was a little biased?? <g>

Both leak and I have learned (from this forum) how to best get a seal and tighten (or not over tighten) the straps BUT the fit in the medium seems snugger (a word?) but again I am not sure as the large feels good to fit on as it does not seem snug at all BUT thinking maybe a little snug is good my cl eyes to just below lower lip is 3 1/2 or close to that..

Sorry to be a pain about this but you guys are my experts and one thing I have read and re-read in this forum is the mask MUST be right!! thakns

I'd try the Shallow cushion (instead of Standard) in both the Medium and the Large. Shallow might be the better cushion shape for you in one of those sizes.

I had to LOL about you having to lift mask to scratch. It never fails as soon as I get my mask all set my nose starts itching. Especially if I am using a nasal or FF mask. I have found that a small finger nail file (the flexable ones) is good to slip under the edge of the mask without causing much of a leak. The rough side is a good scratcher. Try it sometime. Your mileage may vary. jim

I was under the impression that shallow was for smal features (nose etc) no??

ok second day on large mask reading added:

medium night 1
90% = 12.4
system leak = 10.3
AHI = 2.0

medium night 2
90% = 10.0
system leak = 32.8
AHI = 2.6



large night 1
90% = 9.5
system leak = 24.0
AHI = 2.5

large night 2
90 % = 10.5
system leak = 24.0
AHI = 3.3

averages 2 days info on each mask
medium mask Average
90% = 11.2
system leak = 21.5
AHI = 2.3

large mask average
90 % = 9.7
system leak = 24.0
AHI = 2.9

my opinion is second night on medium somehow had large leaks going on
also noted the AHI on the medium mask is lower today's large mask gave 3.3 I think this might mean the medium mask seals better or something heck I don't know that is why I am posting info here <g> thanks for any info/opinions etc