The milk teeth
The tooth of the deciduous dentition corresponds in its structure and form to that of the permanent dentition. Except that the premolars are missing, in their place are the milk molars. There are also no wisdom teeth.
Due to the absence of a few teeth, the deciduous dentition consists of only 20 teeth. Of course, the milk teeth are much smaller and the individual layers of enamel and dentine are much thinner, which makes them more susceptible to caries. The roots of the milk teeth are gradually resorbed until only the crown remains and the tooth falls out to make room for the permanent tooth.
The canine tooth
The canine (lat. Dens caninus, “dog tooth”) is a conical tooth in the dentition behind the incisors and in front of the premolars. The name canine refers to the distinct kink of the dental arch at this point.
In the upper jaw the canine is the foremost tooth in the upper jaw bone (maxilla). Humans have one canine per half of the jaw in the upper and lower jaw, a total of 4 canines. It is in the third position and is the largest tooth in the anterior region.
The canines are the transition between the front teeth (incisors) and the side teeth (molars). The canine is already placed in the deciduous dentition, the first tooth eruption takes place at about 1.5 years of age. The breakthrough of the permanent canines takes place approximately at the age of 11.
Every canine has a root which contains a canal. These roots are partly somewhat flattened. The upper canines also have a distinct root feature with a curvature at their root tip.
Both features are missing in the lower canines. The roots of the lower canines are shorter, so that here the crowns are slightly longer than the roots. Instead of an occlusal surface, the crown of the canines has only a cusp tip (tip of the canine) with two short incisal edges.
The occlusal surfaces of the canines are, unlike the incisors, divided into two halves: a mesial (front) and a distal (back) half. These halves form an angle of about 20° to each other. Furthermore, the canine, like almost all teeth, has a slight curvature from the incisal edge to the neck of the tooth.
The incisal edge of the canines is less pointed than that of the incisors and is not exactly in the middle of the incisal edge, but is slightly shifted forward. There is also a small difference between the upper and lower canines. Thus, the lower canines are usually slightly smaller than the upper ones.
The incisor
The incisors (lat. Dentes incisivi) are used to bite the food. They are located in the front part of the jaw and humans have 4 incisors each at the top and bottom.
This means two middle and two lateral incisors at the top and bottom. In the tooth formula, the central incisors are designated with the numbers 11, 21, 31 and 41, the lateral incisors with the numbers 12, 22, 32 and 42 at the top and bottom. The canines, which also belong to the “front teeth”, border on the incisors.
The distinction of the individual permanent teeth in the dentition is based on their position in the dentition and their function. Like any other tooth in the human dentition, the incisors consist of a crown, the neck of the tooth and the root of the tooth. The crown of the tooth is rather flat and sharp-edged according to its function, the biting of food, which makes it easy to bite off.
In addition, each tooth is made up of different layers, which are covered by the enamel on the outside. On the inside is the dentine, which in turn encloses the pulp. The root of the tooth is enclosed by dental cement up to the transition to the neck of the tooth.
