Teeth: Structure and Dentition

In short: Teeth break food down into smaller pieces and are therefore the first step of digestion. Adults normally have 32 permanent teeth, while children start with 20 milk teeth.

In more detail: Every tooth is made of several layers: hard enamel on the outside, dentine beneath it and, at the centre, the pulp with nerves and blood vessels. The periodontium anchors the tooth in the jaw.

In detail

• Crown and root: The crown is the visible part in the mouth, the root sits in the jawbone, and the neck of the tooth lies in between at the gum line.
• Enamel: Enamel is the hardest substance in the human body and consists mostly of minerals; once it is lost, it does not grow back.
• Dentine: The dentine beneath the enamel is softer and run through with tiny channels, which is why exposed dentine can be sensitive to cold or sweet foods.
• Pulp: Inside the tooth lies the pulp with nerves and blood vessels, which supplies the tooth and passes on signals such as pain.
• Periodontium: Root cementum, fibres, jawbone and gums hold the tooth firmly yet flexibly, so it can give slightly when you chew.
• Types of teeth: Incisors bite off, canines grip and tear, and premolars and molars grind the food.
• Milk teeth: The first milk teeth usually come through during the first year of life; from around the age of six they are gradually replaced by permanent teeth.
• Wisdom teeth: The rearmost molars often appear only in young adulthood or not at all, and sometimes there is too little room for them in the jaw.
• Tooth decay and complaints: Bacteria in plaque turn sugar into acids that attack the enamel; persistent toothache or bleeding gums should be seen by a dentist (zahnpflege-richtig, verdauungssystem-vom-mund-bis-zum-darm).