Instant Smile Teeth MEDIUM Top Veneers Fake Cosmetic Dr Bailey's Dental Makeover This product is NOT a partial denture or a "DENTAL DEVICE" and is intended for temporary use only For aesthetic purposes only. Do NOT eat or sleep while using this product. It is difficult to determine the appropriate size of the Instant Smile teeth for a particular person's mouth. feedback we've received from other buyers, the SMALL size would typically fit a childs mouth or a sm MEDIUM are actually now labeled One Size Fits All and fit an average adults mouth. This is a general guideline and is not a guarantee.