Deviations from the teeth - Pediatric Dentistry
Deviations from the teeth
During the development of the teeth, disorders can arise that cause cosmetic objections.
Deviations arise during the development of the teeth
Deviation in number
A milking teeth normally consists of 20 elements and the permanent teeth consists of 32 elements. Deviations in number occur regularly. Hypodontics or oligodontics means that too few teeth have been applied. The element that has not been applied is called agenetic. Agenesis of the wisdom teeth is the most frequent. But the second premolars and lateral upper incisions are also not regularly installed. Hereditary factors play a role in hypodontics. If a wisdom tooth has not been applied, this is not a problem. Agenesis of incisives can be aesthetically disturbing. Treatment may consist of orthodontic closure of the diastema or replacement of the missing element by an implant with a crown or a partial prosthesis. Anodontics, the absence of all teeth, is rare.
In the case of hyperdontia, there are too many teeth. This is usually a small superfluous element in the upper front, a mesiodens. A fourth molar in the upper jaw also occurs. The breakthrough of hyperdons is often disturbed. Sometimes they are discovered by chance on an X-ray. If they cause problems, extraction is the appropriate therapy (see image below).
Deviations in the breakthrough
In the case of an impacted element, the breakthrough is disturbed by lack of space in the dental arch. The element wants to break through, but cannot. With a fixed element there is a demonstrable reason why the element does not erupt. The element can break through, but does not work. Contaminated and impacted elements are discussed in chapter '' Oral diseases, dental and facial surgery ''.
Ankylosis mainly occurs in milk molars. After the breakthrough, the root membrane decay. The jaw bone continues to develop, but the element does not grow with it. This makes it seem as if the milk molar in the gums drops. The breakthrough of the underlying premolar is often impeded. Due to the absence of a periodontal ligament, normal extraction is not possible and the element must be surgically removed.
Deviation in development
Amelogenesis imperfecta is a structural deviation of the enamel, which is based on a disorder of the enamel organ during tooth development. Little enamel may have formed (hypoplasia) or the enamel may not have been properly mineralized (hypomineralization). Cheese molars are a form of amelogenesis imperfecta and occur primarily in the first permanent molar.
Cheese molars can be recognized because these teeth look mat-opaque and whitish-yellow. These defects can occur in stains or over the entire tooth. Such places are very porous and extremely sensitive to caries. Cheese molars occur in 10-20% of Dutch children (see image below).
Darker discolorations of the enamel can occur due to the use of tetracyclines during pregnancy or early childhood. The elements display brownish-gray and horizontal bands in the glaze. The glaze is strong, but the discoloration is often aesthetically disturbing.
Fluorosis or mottled enamel are white and brown discolorations caused by overdose of fluoride during dental development (see image below).
a Abrasion due to incorrect cleaning habits; b abrasion by grinding.
The treatment of discolouring can consist of bleaching the glaze or camouflage the stains with a composite restoration or porcelain facing.
Deviations arise after the breakthrough
When the teeth in the oral cavity are broken, abnormalities may occur. The best known is caries or tooth decay. The development of caries is extensively discussed in the '' Restorative dentistry '' chapter.
Attrition is wear of the elements by a natural cause. It mainly concerns the occlusal and incisal planes and it is a normal physiological process. The nodules of the molars are becoming increasingly flat. The enamel layer can wear away in such a way that the dentin is exposed. Because this process is very slow, the patient usually does not experience any complaints. The pulp produces tertiary or repair dentin to protect itself.
Abrasion is wear of the teeth due to a non-natural or pathological cause such as grinding and nail biting. Abrasion also occurs in the roots of withdrawn gums. Root cement and dentin are softer than enamel and wear under the influence of incorrect brushing methods (see image above).
In the case of erosion, dental material is lost due to the direct action of acids from food or stomach acid. Dental erosion is further discussed in chapter '' Preventive dentistry ''.