After the initial boil and bite set-up, the mouthpiece will be an excellent fit for your teeth. The use of quality materials ensures the body of the device should not be unduly comfortable to wear. As with all MADs, you may experience a little jaw discomfort and/or wake up with a headache when you are still getting used to the device. This is normal with this type of boil and bite anti-snoring device, but your body will soon adapt and become used to the new positioning of the jaw. If you are unduly worried about discomfort, you may want to consider investing in an adjustable MAD. Such devices cost a little more but allow you to gradually advance your nighttime jaw position slowly over a period days or weeks, at a pace that's right for you.