What to break up mats?

When I got Angel she had some matting.  I used de-tangler spray for kids to help get them loose.  It worked pretty well & didn't seem to irritate her skin.

Just what I was going to suggest.  The detangler stuff for little ones worked great on the cockers.

Dematting comb http://www.dog.com/item/therapet-dematting-comb-straight/193004/

Universal slicker http://www.dog.com/item/universal-slicker-brush/190101/

Poodle comb http://www.dog.com/item/cocker-poodle-comb/190107/

Regular comb http://www.dog.com/item/safari-7-1-4-inch-medium-coarse-comb-model-556/190301/

If the mats are very close to the skin, it might be better to shave and start over.  De-matting is very stressful to some dogs.  Anyway, you always hold the hair next to the dogs skin so that any pulling you do will not pull the skin.  So, if you can't get between the mat and the skin, you can see how it would be pretty hard to do the job comfortably for the dog.

Article on dematting: http://www.bichonfriseusa.com/ref/demattingbbird.htm

 I use a de-matting blade tool and a pin brush on Coke.  If the mats are really tight or close to the skin, I cut them off.  He gets frequent mats in his private area and behind his ears, so I proactively cut this hair off.  You cannot see it anyway, the area behind his ears is covered b/c his ears fold over.

 Personally, I'd have the dog shaved and start over. I'm weird, like that, though. I *hate* dematting dogs.

 Honestly, she doesn't seem to mind it. Once I was done yesterday, she came over and laid on me, so I'd say she's ok about it. Not thrilled, but deals with it ok. I got a good deal out with the pin brush, and I'm sure the groomer is more comfortable with doing it than I am, but her legs I'm nervous to try to comb out. Until Luke, we've always had short haired dogs, and I've had no problems with him since I don't go to bed without at least running the brush through the spots that would be prone to matting.

I know poodles have to get their hair cut, but I have no clue about yorkies. Her hair is definitely more poodle like, and I only know that she has yorkie in her because that was what was claimed. 

 Yorkie hair grows continuously, like Poodle and human hair It has to be trimmed, as well.

Hot Shot is my first long haired dog....ever!  He gets matted behind the ears so easily.  When we first got him it was horrible all over his body but I brush him often now.   He absolutely loves it but.... I cant keep the mats down from his ears, I tried to keep the hair shorter there but still gets matted and it almost seems harder to get those mats out than when the hair is longer.   Of course the cockle burrs that get wrapped up in his hair doesnt help.   I have never used a detangler before, he wont stand for electric shaver and I am afraid to use a blade cause it is so close to the skin.  Really I guess my biggest problem is not knowing exactly how to trim or groom a Berner like him.