I was suffering from pain on the left side of my jaw on and off for a while. After making sure that there were no problems with my teeth on this side, Dr. Tong prescribed wearing a night splint , as she explained that I was probably grinding and clenching my teeth during my sleep. I must say that since wearing this splint , the pain has gone and I feel a lot less tension in my jaw. So I would say that the splint really does work.