Recently I have noticed myself clenching my jaw when I play. About 8 weeks ago I started orthodontia with clear plastic aligners. I don't recall if I clenched my jaw before this but I certainly have been doing it since I got the aligners. I think part of it is that the things don't let me close my teeth normally and I worry about biting my tongue and all that sort of orthodontia nightmare stuff you might remember if you've ever had braces. I have been trying to stop myself from clenching, and it helps that often I am wearing a COVID mask so I will play with my mouth open like a drooling mouth-breather, but I often find that I have I closed my mouth again and am clenching my teeth.
I'm wondering if any of you, orthodontia or not, have had this problem and if you did anything to solve it. I don't want this to become a permanent habit.
Clenching or working your mouth around is pretty common. I still do it to some extent. It seems to have to do with focused concentration. It isn’t a great thing to do but better than having tension in your playing. I know an otherwise normal adult who drools when he plays the fiddle…
This is a common issue. It can often be caused by the chinrest or shoulder rest setup. It may be that your setup is too high and it’s pushing up into your jawbone too much. Try playing without a shoulder rest or with a lower chinrest for a little while to see how it affects the tension in your jaw/neck.
If you find that you do need something in between the violin and your body, take the time to adjust it properly. Shoulder rests are meant to be adjustable, and the newer models like the Pirastro rest offer a much wider range of fitment.
While it can be an issue with chin rest and shoulder rest as Rich says, I believe it's most common as a result of intense focus when playing, and banjo players, mandolin players, and doubtless others also deal with it. Get your set up right for sure, and then take time to practice relaxing your whole face as you play. It can be a challenge.
I don't think I can adjust my chinrest any lower. I have a very short neck and my chin rest, although not adjustable in that way, is nearly touching the body of my fiddle now already anyway. I have played without one in the past and it seems like a chinrest helps keep me from getting nerve pain in my left index finger. I suppose I'll try to go without it and see if that stops me from chomping down. I've drooled on my fiddle a lot! I drool all the time! It's so embarrassing!
sb -- I've collected my share of chin rests, and a couple of them allow my chin to hover remarkably close to the fiddle's top. You can also attach the chin rest in a lot of places along the lower bout, all to maximize comfort & playing ease. Go nuts! Try the rest in one position. Then move it a fraction of an inch and try it again. Of course, you do need the wrench...which I'm sure any fiddle dealer will gladly supply if you buy a chin rest from them.