The molars form an important part of the human dentition. They are divided into anterior and posterior molars.
What are molars?
In addition to incisors and canines, molars are also part of the dentition. They are also called posterior teeth and are divided into two groups. These are the premolars or anterior molars (Dentes praemolares) and the molars or posterior molars (Dentes molares). Their structure and functions differ from the other teeth. For example, they are usually equipped with several roots, while canines and incisors have only a single root. The molar tooth already occurs in the infantile milk dentition. However, the milk dentition has fewer molars than the dentition of an adult. In terms of structure and function, however, there are no differences between milk molars and permanent molars. In contrast to the posterior molars, the anterior molars are already contained in the deciduous dentition. There they can be used for grinding food.
Anatomy and structure
In modern times, humans are equipped with only two front molars on each side of the jaw. They bear the dental designations 14, 15, 24, 25, 34, 35, and 44 and 45. In the dentition of human ancestors, the number of premolars was still double, so that there were four anterior molars in each half of the jaw. The characteristics of human premolars include two to three dental crown cusps. They allow the molar to grind food. In the lower premolars, there is a highly pronounced crown alignment. Each anterior molar has a different number of roots and root canals. For example, specimens 14 and 24 normally have two tooth roots, two tooth canals, and two tooth cusps on the upper surface. In contrast, anterior molars 15 and 25 have only one tooth root and one or two tooth canals. They also have two cusps on the tooth surface. On teeth 34 and 44, one root and one root canal are present. Occasionally, two canals may also occur in them. Teeth 35 and 45 also have only one root and one root canal, but they have two to three cusps. The posterior molars are also called accessory teeth because they do not occur in the primary dentition. The grinders are characterized by their size and strength. Their features include dimples and cusps. In the human dentition, there are three molars on each side of the jaw, so that there are twelve molars in total. The last molar, which erupts between the ages of 18 and 25, occupies a special position. This is why it is called the wisdom tooth. Just as with the front molars, the number of roots, cusps and canals of the back molars varies. For example, teeth 16 and 26 have three tooth roots, four tooth cusps and four tooth canals, while teeth 17 and 27 each have three roots and root canals and five tooth cusps. Teeth 37 and 47 have the same structure, but only four cusps. No exact number of roots, canals, and cusps can be determined on teeth 18, 28, 38, and 48, as they vary from individual to individual
Function and tasks
The task of the anterior and posterior molars is to grind the ingested food, which is first crushed by the incisors. To perform this task, the molar is equipped with a flatter and wider surface than the incisor and canine. The structure and surface also differ from the other teeth for this reason. The cusps of the molar have a special function. They improve and facilitate the grinding of food. The cusps cause the molar tooth to have numerous small dimples, which in dentistry are called fissures. However, these fissures have the disadvantage that they make brushing teeth more difficult. As a result, there is a higher risk of caries at the pits.
Diseases
As with the incisors and canines, the molars are also at risk of being affected by damage. Among the most common diseases of the molar tooth is caries (tooth decay).This risk is even more pronounced for molars and premolars than for the other teeth because they are more difficult to clean. For this reason, there is a risk of losing a molar tooth at a relatively early stage. Since the molars are exposed to considerable stress, caries is not uncommon in them. Tooth decay is caused by bacteria that break down the sugar within food into acid. The tooth structure is attacked by this acid. The first signs of caries are light or brownish spots on the surface of the molar. As the caries progresses, deeper structures such as the dentin (tooth bone) and the tooth nerves are also attacked, which eventually leads to pain. Often, a costly root canal treatment must then be performed. Sometimes it is even necessary to extract the affected molar. Molar problems also include discomfort at the wisdom tooth or a wisdom tooth eruption. In addition, wisdom teeth can shift horizontally in the jaw due to lack of space. Molar pain is also not uncommon. In most cases, removal of the affected wisdom tooth is then necessary.
Typical and common dental diseases
- Tooth loss
- Tartar
- Toothache
- Yellow teeth (tooth discoloration)
