Tooth occlusion is the closure of the lower and upper row of teeth (bite). Many dentists argue about the method for determining occlusion and articulation. Some believe that articulation is the contact of each row of teeth with each other at the time of movement, and occlusion is the same only at rest. At the same time, articulation and occlusion continue to be the main factors that determine the relationship between the teeth: the load on the muscles, joints and the teeth themselves. With the correct closure of the dentition, a person develops the correct bite, which significantly reduces the load on the mandibular joints and teeth. If pathology has developed, then the rapid destruction of the crown, periodontal, as well as a change in the shape of the face begins.
Definition of occlusion
It is the occlusion of the teeth that is responsible for their proper location in the oral cavity. Under the condition of normal operation of this system in the oral cavity, the chewing muscles, temporomandibular joints and crown surfaces perform complex work.
Stable occlusion can be achieved using multiple fissure-tubercle contacts of the lateral molars. The correct position of the dentition in the oral cavity is considered a mandatory factor, without which periodontal tissues are quickly damaged and chewing load is not distributed correctly.
Symptoms of malaise
Violation of tooth occlusion leads to difficulties with the process of chewing food, which is accompanied by pain, migraines and clicking in the temporomandibular joints.
Due to improper closure, the tooth crown is actively erased and destroyed. It is these processes that lead to dental diseases: periodontal disease, gingivitis, stomatitis, loosening, early tooth loss.
With too much occlusion, the incisors located on the lower jaw begin to injure the mucous membrane in the mouth, as well as the soft palate. It becomes difficult for a person with such a malaise to chew solid food, he has problems with breathing and articulation.
How does it appear during an external examination?
Problems with occlusion lead to a change in facial features, as well as its general shape. Depending on the type of violation, the chin either decreases in size or moves forward. It is possible to note the characteristic asymmetry of the lower and upper lips.
With a visual examination, you can easily notice the incorrect arrangement of the rows of teeth in relation to each other, the presence of diastems, as well as crowding of the incisors.
At the time when the jaw is inactive, a gap of 3 to 4 millimeters remains between the chewing surfaces of the teeth, which is also called the interocclusal space. With the development of the pathological process, this distance begins to decrease, or, conversely, to increase, which leads to an incorrect bite.
The main varieties of occlusion
Specialists classify the dynamic as well as the static form of violation. With dynamic occlusion, special attention is paid to the interaction between the rows of teeth at the moment of movement of the jaw, and for static occlusion, the nature of the closure of crowns in a compressed state.
In turn, occlusion of a static type is divided into pathological anterior, central and lateral. Detailed description of types of tooth occlusion:
- Central. With such a violation, the location of the jaws is maximal inter-tubercular, the upper crowns overlap the lower ones by a third, the lateral molars have a fissure-tubercular contact. When considering external signs, no special changes can be noticed.
- Front occlusion. The lower jaw is strongly shifted forward, the incisors form an end-to-end, the closing of the chewing teeth does not occur, between them there are cracks similar to a rhombus. When considering external signs, it should be noted an insignificant protrusion of the chin and lower lip forward, as well as the "angry" facial expression in a person.
- Lateral occlusion of the teeth is a displacement of the jaw in a certain direction, most of the chewing load falls on only one canine or chewing surfaces of the molars from the side to which the jaw is shifted. External signs are as follows: the chin is shifted to the side, the midline of the face corresponds to the gap between the front incisors.
- Distal. With this form of disturbance, a strong displacement of the lower jaw occurs forward, and the upper premolars overlap with the lower buccal tubercles. When examining the patient’s face, one can distinguish a chin that is strongly advanced forward, as well as a concave type of face.
- Deep incisal occlusion. In this condition, the incisors of the upper jaw overlap by more than 1/3, the patient does not have a cutting-tubercle contact. When considering external signs, one can note a small chin size, a large lower lip, as well as a prominent nose (in other words, a “bird” face).
What are the reasons for the development?
Occlusion of teeth in humans can be acquired or congenital. Congenital is laid at the stage of development of the child in the womb, acquired acquired develops throughout life.
Problems with a bite in most cases are detected in adolescent children at the time of the change of primary teeth to permanent.
The following negative factors can affect bite problems:
- genetic predisposition;
- congenital malformations of the jaw, birth injuries;
- bad habit of sucking a finger in childhood or giving up a dummy too late;
- an increase in the size of the tongue that does not meet the norm - macroglossia;
- teething times are very different from those accepted as normal;
- destruction of milk molars by caries;
- problems with the formation of the temporomandibular joints ;
- the development of diseases of the central nervous system;
- improper nasal breathing, especially at night;
- the onset of the inflammatory process in the chewing facial muscles.
Occlusion is also divided into temporary and permanent. During the birth of the baby's jaw is in a distal position.
Up to the age of three years, the child has a rapid growth of bone structure, and milk teeth develop according to their anatomical position. It is these processes that are responsible for the formation of the correct bite with a central closure of the dentition.
Diagnostic measures
The orthodontist and dentist are involved in the diagnosis of such a disorder. The specialist conducts a visual examination and determines the severity of the closure of the dentition, implements a jaw of the alginate mass.
Next, the finished cast of the jaws undergoes additional checks for the presence of pathology, and the size of the interocclusal fissure is also measured. Some patients are additionally prescribed an occlusiogram, orthopantomography, electromyography and tele-radiography in several projections at once.
After receiving the results of TRG, a professional assesses the state of bone structures and soft tissues, which helps to determine further actions and develop orthodontic therapeutic measures.
Determination of central occlusion with partial absence of teeth
Diagnosis of central occlusion is very important for prosthetics with a partial or complete absence of teeth in the oral cavity. During diagnostic measures, special attention is paid to the height of the lower part of the face. In case of incomplete adentia, the location of antagonist teeth is taken into account, if there are none, then the mesiodistal ratio of the jaws is determined by means of wax bases.
Methods for diagnosing central occlusion:
- A functional method for determining central occlusion with partial absence of teeth. During the procedure, the patient throws his head back on the back of the dental chair, and the doctor puts his fingers on the surface of the teeth of the lower row and asks the patient to touch the sky with his tongue and begin to swallow. When making such movements, the lower jaw is moved forward involuntarily, as well as the occlusal surfaces come closer together.
- The instrumental method for determining central occlusion with partial tooth loss is carried out using a specialized tool. It helps to accurately determine all movements of the lower jaw.
Complete absence of teeth during occlusion
Diagnosis of central occlusion is carried out according to the inverse principle - the height of the lower part of the face is revealed. There are several ways to determine central occlusion in the absence of teeth:
- anatomical;
- functional physiological;
- anatomical and physiological;
- anthropometric.
The anatomical and anthropometric method is based on a detailed study of the proportions of specific profile face lines. The anatomical and physiological method of research is the identification of the resting height of the lower jaw.
The dentist during an external examination determines the points on the site of the base of the wings of the nose and chin, and then measures the distance between them.
After that, wax rollers are inserted into the oral cavity and ask the patient to close the jaw and open it again - this helps to determine the distance. In the normal state of occlusion, the indicator should be no higher than 2-3 mm than at rest. If there are any problems, the doctor sets the changes in the lower part of the face.
How is the treatment carried out?
Malocclusion can be eliminated through specialized orthodontic constructions. If there are minor problems with occlusion, the dentist prescribes a facial massage and the use of removable silicone mouthguards, created according to the individual parameters of the patient.
Devices for bite correction are used throughout the day, removed before bedtime, as well as with meals.
In the treatment of tooth occlusion in children, special face masks are used. Older children are prescribed vestibular plates, Bappin's mouth guards. According to indications, Frenkel, Klammit and Andresen-Goiplya activators are used.
Braces system
Braces are fixed orthodontic devices that are created to correct dentition. The device fixes each tooth in a certain position, and by means of a fastening bracket, it corrects the direction of its development, which helps to form a good bite.
Braces can be vestibular and mounted on the front of the crowns, as well as lingual, attached near the tongue.
Braces systems are created from metal, ceramics, plastic or combinations. The time of wearing the system will directly depend on the severity of the violation, the age of the patient and following all the advice of a specialist.
Orthodontic devices
Activator devices are also used to restore occlusion. The design includes two base plates, which are connected in a monoblock by arcs, brackets and separate rings.
Through this design, the correct position of the lower dentition is restored, the growth of the small jaw is stimulated, and the deep bite is removed. In this case, there is an inclined or case displacement of the teeth in a certain direction.
Operation
Surgical measures are performed for congenital malformations of the jaw and when other methods do not bring any positive effect. The operation is carried out in a hospital under general anesthesia.
The bones are fixed in a certain position, fixed with metal screws and a special tire is placed on them for several weeks. After the patient has to wear a correction device for a long time.