A torus (plural: tori) is a protuberance in the jaw bone, commonly found in the middle of the hard palate, or on both sides of the mandible, beside the tongue. They are hard and rounded, and grow gradually in size, and are not common in young people. They are found in 10-40% of adults. They are usually not so large in size as to affect speech and chewing. Larger sized tori can make removable appliances like retainers or dentures less comfortable to wear.