Most people associate digestion with the stomach and intestines, but the Nemours Kids Health site explains that the digestive system actually begins in the mouth. Human teeth play an important role in preparing food to enter the stomach for the main part of the digestive process. They are designed and shaped perfectly for this function.
Human teeth consist of four different kinds of tissue. The inner part is pulp, which contains nerves, connective tissue and blood vessels to feed the root. This is surrounded by a hard, yellow material called dentin. Enamel makes up the next layer and shields teeth from bacteria, heat and cold. Cementum, the fourth tissue type, covers the tooth root below the gum line and keeps the tooth in place.
Kids Health explains that human teeth come in several types, each of which is geared to chewing a certain kind of food to prepare it for swallowing and digestion. Incisors are square and sharp-edged. They are primarily used for biting into food, while the long, sharp canines tear it. The bicuspids are flat to mash and grind food as you chew. The molars have points and grooves that make them efficient at vigorous chewing.
Human teeth work with the salivary glands to process food for swallowing. The tongue pushes food against the teeth, and saliva is released from glands in the walls and floor of the mouth as you chew. Saliva eases chewing and swallowing, particularly for dry foods, according to Kids Health. It also contains enzymes that start the digestive process for carbohydrates while food is still in the mouth. It is eventually swallowed once the teeth have turned it into a moist, soft mass.
Human wisdom teeth fall into the molar category. Kids Health says they are believed to have provided extra chewing power thousands of years ago, when humans mainly ate raw foods. This more natural diet required extra chewing power to process it for digestion. Now they are often removed because they serve no needed purpose and can crowd out other teeth and cause pain.
Tooth loss can affect digestion because people with missing teeth are often unable to chew their food property. This can be corrected with bridges or implants to fill in the gaps or dentures to replace an entire mouthful of missing teeth. The Dental Implants patient information site recommends replacing teeth as soon as possible because full dentures impede eating. It says half of all full denture wearers avoid some foods, and 29 percent only consume soft or mashed foods.