No, but the entire device is moldable and should be good for all mouth sizes. If you are worried your mouth may be too small, you can check the size of the device before trying to mold it to your teeth. Pop it inside your mouth. If it extends beyond your back teeth, you can use a sharp knife to cut it down to size. If you are left with any sharp edges after trimming, you can smooth them away with your fingertips as part of the boil and bite process.