Teeth and the human dentition

Human teeth are used to grind food. Permanent teeth only grow from around 9-11 years of age. As the hard tooth enamel cannot regenerate, it requires adequate protection through careful dental care.

Teeth and the dentition

Like many other vertebrates, humans have real teeth. These are hard structures that are found in the oral cavity and are used to grind food. What is unique, however, is that in humans they not only play a major role in food intake, but also in communication . For example, the teeth are often used in the formation of sounds and especially in the formation of s-sounds.

Biology makes a fundamental distinction between real and false teeth. The distinction is based on the composition of the tooth. While real teeth consist of several hard substances such as enamel, dentine and cement, false teeth are made of horn. This is why human teeth are also called "dentin teeth".

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Types of teeth

Teeth are divided into different categories according to their function and when they were formed .

Differentiation according to the function of the teeth

Each tooth in the human dentition fulfills its own function and is anatomically adapted to this function. A distinction is therefore made between

• Incisors
• canines
• premolars (premolars)
• Molar teeth (molars)

The incisors are located directly at the front of the dentition. Their task is to cut food and thus enable a piece of food to be bitten off. For this reason, the incisors are very sharp. Together with the canines, they form the front teeth in humans.

The canines are significantly longer than all other teeth and have a conical shape. They are located directly between the incisors and the premolars. Their name refers to the typical bend that the human dentition makes at this position. This gives the impression of a corner. Its main task is to hold the food in place and thus enable the front teeth to cut.

The premolars are also called premolars. It has two to three cusps and partially grinds the ingested food. In the milk tooth stage, the premolars take over the entire grinding function.

In adults, the so-called molars or cheek teeth also form. These are used exclusively for grinding food. In this way, the teeth prepare ingested food for subsequent digestion in the stomach and intestines.

Computer representation of all human teeth frontally and in top view of the tooth surface

Differentiation according to time of formation

During the first few years of a person's life, so-called milk teeth grow. This is a temporary set of teeth that is completely renewed during adolescence.

The first permanent teeth erupt in most people between the ages of nine and eleven. In contrast to the dull milk teeth, these have a strong, white color.

In addition, some people develop so-called wisdom teeth from the age of 17. These sometimes differ significantly in their structure from the other teeth. Although they should generally have four cusps, in some people they have three or five cusps. The number of roots also differs greatly. Furthermore, in some cases they are fused together or even curved in a hook shape. While a complete set of human teeth always has a maximum of four wisdom teeth, additional teeth sometimes grow behind them. However, these are very rare. Only 0.001% of all people have a set of eight wisdom teeth.

Structure of the teeth

The human tooth consists of three main sections:

• crown
• tooth neck
• Tooth root

Structure of a tooth

The tooth is made up of different layers. With the naked eye, however, an observer can only see the enamel of a healthy tooth.

Tooth enamel is the hardest substance that occurs naturally in the human body. This protective layer is formed from the so-called adamantoblasts and consists almost entirely of hydroxyapatite. This crystalline material is formed from calcium and phosphate. The enamel surrounds the entire tooth and protects it from external environmental influences.

Directly underneath is the dentin. This is the main material of which a human tooth is made. In addition to calcium and phosphate, it also contains a high proportion of protein and water and is therefore significantly softer. It is also sensitive to pain and is quickly irritated by both cold and heat.

All stimuli are transmitted to the central nervous system via the nerves in the pulp . This surrounds the root segments and also has numerous blood vessels. As a result, it nourishes the entire tooth and supplies it with nutrients. The root segments , on the other hand, anchor the tooth in the jaw and ensure a firm hold. They are surrounded by a thick layer of gum.

Dental diseases

Numerous diseases affect both the gums around the root segments and the tooth itself. In most cases, this is manifested by severe pain and reduced chewing ability.

The following diseases and complaints requiring treatment mainly occur in humans:

• abscesses
• Chronic bad breath
• Gingivitis(inflammation of the gums) and other gum diseases
• tooth decay
• periodontitis
• teeth grinding(bruxism)
• Misaligned teeth.

In most cases, abscesses in the gums lead to severe fever and unpleasant swelling. A severe infection causes enormous pain and loss of appetite. These encapsulated accumulations of pus are usually caused by persistent inflammation of the tooth root. In some cases, however, they also occur when the first wisdom teeth erupt.

Unpleasant bad breath can be caused by numerous ailments. While the cause of short-term bad breath is usually in the esophagus or stomach, chronic bad breath is caused by dental disease. A medical examination is advisable if these symptoms persist.

Caries is the most common dental disease. Acids caused by the bacterial breakdown of sugar increasingly break down the tooth enamel. As a result, the tooth loses its natural protection and becomes susceptible to other damage. However, regular tooth brushing and avoiding sugary foods completely prevents the occurrence of this disease.

How are dental diseases treated?

Dentists have several methods at their disposal for treatment. Fluoridation is usually used for advanced caries. In addition, many doctors also use dental sealants or remove the affected teeth completely. If only a few areas are affected, the dentist hollows them out with special tools and then fills them with one of many possible fillings.

The rarely occurring inflammation of the dental nerve, however, requires comprehensive root canal treatment. The doctor exposes the root of the tooth and kills all bacteria using a laser. Finally, he repairs the hole with a filling.