I have read a few problems people have encountered with chewing gum excessively. I have chewed mastic gum but not daily and not for more than an hour. My molars are tipped in and I have a cross bite. I am not sure I have derived any benefit from it even from trying to emphasise chewing on the side I had not used. I found it difficult to chew gum with my incisors which need to be straightened, tipped out. I currently use a Jawzrcise for this objective. I have noticed that biting down on it frees me from the habitual skewed bite that I have adopted and allows me to play with the lateral position of my mandible in the movement. As I write it I know that sounds like a recipe for TMJ problems. So far none. I see it as an opportunity to fix my skewed biting action. I think this is important as the skewed biting action seems likely to act to maintain my crossbite. If this is of interest, I would add that I started with the medium resistance one and it soon became easy, but a few weeks in is still useful. I do not expect to bother buying the stiffer one.

I chew mastic gum 1 to 2 hours a day and I eat 2 large bio carrots, one for each side daily. I maintain proper neck and spine posture during this. No TMJ yet.

My teeth are tipped in both up and down and my left side is lower than the right side, so I have an overbite despite having had braces, 0 cavities and teeth in top shape, almost unused lol.

I did notice slight changes to the inter-molar with now with mewing and its affecting how my teeth fit together when I chew. I have been at it only 2 weeks tho, but they seem to be straightening. I already see some small improvement in the overbite.

OPEN MOUTH CHEWING with mastic gum is significantly better for moving your maxilla and affecting teeth as you bite harder, you will feel it in your teeth and jaws for sure. I also seem to manage mewing during sleep and wake up with a sore maxilla especially back molars and left side.

The very first thing i noticed tho is the lower lip. O.o it seems to be healing???, becoming smaller? It used to be cracked all the time... stopped doing that around mid week 2 tho. I also seem to have had swelling in the lower lip and the mouth due to mouth-breathing? Seems to be receding as well.