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Distal (prognathic) occlusion in human

Distal prognathic occlusion in people

Improper closing of dentition leads to many problems. Except external changes, a person has difficulties in chewing food.

Doctors note that a malformed occlusion leads to a change in body proportions that violates many functions of the body. To avoid such anomalies there is a need to react promptly to the formation of the distal occlusion, provide medical procedures and take preventive measures.

Classification And Types

The prognathic bite is easily identified by a special arrangement of the jaws: the top row of teeth is significantly pushed forward and the bottom is pushed back. In addition to the apparent displacement when occlusion teeth twisting is observed.

It is accepted to provide two clinical forms. They differ among themselves in the structure of the jaw, the location of the canines and incisors:

  • The first form. Teeth opening when the patient smiles, reminiscent of a fan. Side teeth have a noticeable shift inward, having a look as they are narrowed outwardly.
  • The second form. Incisors and canines, which are on the upper jaw, are directed inwards. Basically, only the central teeth are arranged so, the side teeth direction is towards the lips.

Based on this classification, it is agreed to distinguish between the following types of distal occlusion:

  • the normal development of the upper jaw and insufficient of a lower;
  • overdevelopment of the upper jaw and underdevelopment of the lower;
  • the lower jaw is normal, and the upper lip is very large;
  • cutters are strongly jutting forward.

This classification of clinical forms of occlusion was established by mr. Betelman. In modern orthodontics it is applied only for adults, it is believed that the occlusion with baby teeth is not fully formed.


Occlusion is a common problem that occurs in a large number of people, especially in childhood. An experienced orthodontist will determine its presence in appearance. One of the first symptoms is an upper lip baked forward.

As a result of this, the patient’s mouth is always slightly open. When smiling you can see the upper incisors, arranged like a fan. If we look at a person in the profile, it can be seen a bulge in the area of the jaw, and a shortening of the lower face. A prominent crease on the chin is an obvious symptom of occlusion include.

upper teeth overlapping the lower

Photo: Distal (prognathic) occlusion

As external and internal signs, a doctor determines the clinical form of occlusion. The main symptoms include:

  • The teeth located at the top, are considerably narrowed.
  • Cutters resemble an open fan, and they are pushed forward and slightly twisted.
  • The compactness of the lips is normal.
  • Lack of longitudinal openings between the jaws.
  • The lower lip is noticeably thickened.
  • For the upper jaw, it is the typical location of the incisors and canines to be turned inside.

Even minor malocclusions lead to problems with speech apparatus, violate the process of breathing and eating.


One of the main factors leading to the formation of these anomalies is heredity. Also, changes are taking place under the influence of concomitant causes. These include chronic diseases, injuries, bad habits.

It should be borne in mind that all children are born with the distal position of the lower jaw. The norm is considered to be the presence of a distance 1-10 mm from the upper jaw. Therefore, the baby can have a longitudinal slot.

In the normal development of the child and feeding with breast milk, a transition from prognathic occlusion to orthognathic takes place.

The main causes of distal occlusion include:

External factors

Among them, the presence of common diseases in the patient. Statistics show that such violations occur in 60% of children who had been ill with rickets.

Also to the anomalies of the teeth lead trauma, inflammatory processes in the oral cavity, short frenulum of a tongue. Malocclusion can occur even when the child lies wrong during a day rest or sleep.


Studies have shown that 80% of the occlusion are transmitted by heredity. This does not mean that every child receives this anomaly at birth.

Just a baby who is predisposed to this phenomenon, which may occur as a result of favorable conditions. To prevent the development of malocclusion one should promptly resort to preventive measures.

Diseases of the nose and throat of a chronic nature

a child at otolaryngologistStatistics show that about 35% of children suffering from diseases, leading to a violation of nasal breathing, face malocclusion. Such diseases include deviated septum, adenoids, or chronic rhinitis.

Also, occlusion can develop in children, who often suffer from colds. During these periods a child mostly has a mouth breathing, thus forming the high palate. As a result, these children have narrowed upper jaw which bulges forward.

Children’s harmful habits

The most common of them is a habit of thumb sucking, tongue, or any items. If this turns into a constant habit, over time, a change in proportions of the face and the deformation of the dentition takes place. As a result, a prognathic occlusion is formed in a child.

Among the bad habits abnormal swallowing, breathing not through the nose, but through the mouth or tongue pressure on the dentition are also noted. Also, there are disorders associated with chewing or speech articulation. Quite often, a child combines a few habits or changes from one to another.

Bad posture

As a result of changes associated with the spine, there is a set of pathologies, including orthodontic. Most often, such a push is in favor of the child bad posture.

The head of the baby should be on the same vertical line with respect to the spine. Incorrect posture leads to its displacement forward and forming malocclusion.

The early loss of milk teeth

If the baby’s teeth are badly damaged by caries, the doctor may decide to remove them. There is also such a procedure when restoring a trauma jaw. As a result, free space starts to be filled with adjacent teeth.

Subsequently, when an eruption of molars takes place there is no place in the oral cavity for them. This leads to their defection and malocclusion.

Possible Consequences

Violations that occur in the anomalous location of the jaws, affect not only the person’s appearance. Also, there are changes in other body systems.

The most serious consequences include:

  • Violation of facial proportions. Since the front jaw is strongly pushed forward, the chin becomes small. This changes the proportions of the whole person. A patient with a flat chin always looks like a child, the impression of the weakness of character of the person.
  • Violation of masticatory functions. When prognathic occlusion it is impossible to close the jaw during chewing. Back teeth carry a double burden, so they break down more quickly.

    During the absorption of food in these people, the grinding or crushing motion is observed. Chewing the period increases by 30% when compared with the normal process.

  • The risk of diseases of the oral cavity. Not in time corrected occlusion leads to the fact that a person gets used to the inconvenience associated with its development.

    Such patients do not take into account the fact that the loose teeth are more prone to diseases. The most common are the development of caries and periodontitis.

  • Problems with the temporomandibular jaw apparatus. Patients with malocclusion experience discomfort while talking or eating. It is expressed in a poor mobility of the jaw due to the reduction of its flexibility. Also, a smile or swallowing may be accompanied by the crunch.

Difficulties may also arise if the patient dares to resort to a prosthesis. The lack of symmetry and the inability to close the jaw complicate the work of the doctor.

Treatment In Adults

using braces for treatment Distal occlusionIf timely treatment was not carried out in a childhood, then doctors recommend resorting to the installation of braces. Quite often, for correction of the distal occlusion among the adults, a dentist carries out an operation to remove the two front teeth on the top jaw. It is necessary for at the time of wearing braces to form a normal occlusion.

If removal is not possible then settings that push the lower jaw forward is used. Such systems include a spring of Sabbah, the unit of Herbst.

The process of treatment is long and painful. Treatment is chosen by a dentist individually. At the same time, he pays attention to the shape of the occlusion, the patient’s age, the structure of the jaw apparatus and other features. Surgery is recommended in very advanced cases.

To prevent relapse after treatment, devices designed to fix the result are to be worn. This may be removable or non-removable structure plate. The duration of the prophylactic period is a year; some patients have to wear similar installations throughout their lives.

Treatment In Children

Most orthodontists agree that to correct abnormalities of the jaw apparatus is only until the child reaches 13 years of age. The smaller the child, the easier passes the therapy. In the initial stages, it is enough to eliminate the cause that leads to the distortion of the face.

To correct a distal occlusion doctors put special plates in the oral cavity of children. They are made of safe materials, so they do not cause harm to the child. Their main task is to stimulate the development of the mandible and deceleration of similar processes for the top.

Among the popular removable plates for children should be noted:

  • bionator of Janson;
  • Klammt’s activator;
  • Frenkel’s apparatus.

In addition to these facilities special phones that look like boxing, tires are made of silicone. They are also used to get rid of malocclusion.

Among them, it is worth noting miobreys, trainer, LM-Activator. The main difference between the plates is that they are made in certain dimensions, while not taking into account the individual characteristics of a patient.

These installations are characterized by high efficiency. They are used only in the period of growth and development of the jaw apparatus. They affect not only the child’s jaw but also the muscles, teaching good habits. This is necessary to prevent recurrence after removal of the plates.

Since the distal occlusion can lead to serious consequences in the future, the experts recommend watching after the baby. Especially pay attention to bad habits, incorrect swallowing, and problems with speech.

Parents should also be alerted by constantly open mouth of the baby. In the case of alarm symptoms, you should visit the ENT specialist, consult a speech therapist and a psychologist.

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