Occlusion - contact when the teeth are closed. The orthodontist deals with such problems. Orthodontics of mesial occlusion includes all sections of this phenomenon - from etiology to treatment and prevention.
A mesial bite is an abnormal occlusion in which a row of teeth on the mandible overlaps the teeth of the upper row during closure of the jaws. Then a characteristic step is formed. Pathology is observed in 11.8% of patients. It is considered a complex dentoalveolar curvature. The opposite of it is a distal bite, where everything is exactly the opposite.
General information
Mesial occlusion can be combined with other irregular bites - vertical and transversal (cross), with the transposition of individual teeth, accompanied by an open bite. In dentistry, mesial occlusion is called “progenia”, “anterial bite”, and lower prognathism. Most often, the upper jaw or the too developed lower jaw is underdeveloped.
The term “mesial bite” was introduced into orthodontics as early as 1926 by Lisher. And in 1899, E. Engle created a classification of dentoalveolar pathologies, where he attributed progeny to class III anomalies, which means the location of the first chewing teeth (molars) in front of the upper when closing.
For centuries, people with such problems in the form of a bulky lower jaw have been classified as demented, but among them there were outstanding personalities - Emperor Charles V and the great composer Richard Wagner. Photos of mesial occlusion will be presented below.
Causes of anomalies
The mesial bite is polyetiological - it can cause genetic disorders, congenital and acquired factors. Genetic types of progenia occupy 20-40% of all cases and are associated with those features of the facial bones of the skull that are passed down through generations.
In the prenatal period, the cause of the disturbances is the diseases of the pregnant woman, trauma and pathology of the birth, jaw hypoplasia, etc. The provocateurs can be the teeth of the lower jaw in the supercompletion, adentia of varying degrees on the upper jaw (lack of teeth), microdentium of the upper teeth, shortening of the frenum of the tongue or its big sizes.
The causes of mesial occlusion of the dentition can also be:
- rickets suffered in childhood;
- artificial feeding;
- improper posture of a child in a dream (lowering the head to the chest);
- propping chin with a cam while sitting;
- osteomyelitis of the upper jaw;
- ENT diseases (chronic tonsillitis, curvature of the nasal septum);
- early change of milk teeth of the upper jaw;
- unevenness of erasing children's teeth (fangs);
- growth retardation of permanent teeth.
If the milk fangs have not faded in time, this will also contribute to the extension of the mandibular part of the skull to the front position. In this position, she remains stable. Bad habits such as sucking a finger, tongue, upper lip, and a permanent nipple in the mouth have a very negative effect on the appearance of progenia.
Classification
There are 3 forms of mesial occlusion. They will be discussed below. So, the classification of pathology:
- True mesial occlusion, or open - is a gene pathology and occurs in representatives of the same genus, becoming their hallmark. An incorrect bite is diagnosed in the first year of life. The provoking gene is found in descendants in 30% of cases. Often a contributing moment is the cold of a pregnant woman in the first trimester.
- False, or closed progeny - a prolonged stay of the lower jaw in the extended state for various reasons: inflammation of the nasopharynx, when breathing is carried out mainly by the mouth, becomes a provoking factor. A short frenum of the tongue (uncut) can also be the cause. Anomaly becomes noticeable when the teeth close. Diagnosis becomes possible after 12 years. Visually may be invisible.
- Combined forms of mesial occlusion - a combination of 2 previous options. This form is the worst diagnosed and treated.
Given the broken bite in the sagittal plane and the angle of the lower jaw in the classification of mesial occlusion, 3 degrees of Angle pathology are distinguished:
- The first degree is the sagittal gap between the incisors of the jaws from 3 mm, but not more than 5 mm, the mandibular angle is up to 131 °.
- The second degree is the sagittal fissure up to 10 mm, the mandibular angle up to 133 °.
- The third degree - the sagittal fissure is greater than 10 mm - 11-18 mm, the mandibular angle is up to 145 °.
What is the sagittal fissure? This is the distance from the front teeth of the upper jaw to the front teeth of the lower. By the way, with a sagittal fissure greater than 10 mm, a young man can be considered conditionally suitable when called up for military service. The specified systematization was created back in 1898 and has drawbacks.
Angle here takes into account the displacement of the teeth only in the sagittal direction, but the displacement practically occurs in three mutually perpendicular directions. Therefore, today such a classification has only a historical aspect, although in some places it is used abroad.
Mesial bite can be of 3 types: open, deep and cross.
Forms
There are 3 forms of bite of the mesial type:
- The first form - there is no sharp difference in the development of the jaws, the central incisors of the mandible overlap the upper teeth.
- The second form - the lower teeth reach the mucous membrane of the upper lip. The lower jaw is more developed and massive than the upper, but not by much.
- The third form - in this embodiment, the upper jaw is smaller in size than the lower. The front teeth do not touch. The tongue strongly presses on the upper teeth.
Dental alveolar and gnatic clinical forms of mesial occlusion are also distinguished. In the first case, the lower jaw can arbitrarily shift to the correct occlusion of the chewing teeth. The gnatic form of displacement does not.
Symptomatic manifestations
Mesial occlusion corresponds to the closure of molars according to Engle's 3rd class - this is a sagittal malocclusion. In this case, the mesial displacement of the crowns of the first chewing teeth by 0.5 width of the tubercle or more is the main diagnostic sign.
The clinic of mesial occlusion in the external manifestation is expressed in a massive extended chin (courageous), the profile of the middle part of the face becomes concave to varying degrees, the upper lip sinks and the lower lip is protruded.
Facial expression becomes angry. Such a face in men is often considered even attractive and courageous, but for a woman this characteristic is opposite in meaning.
The upper lip seems smaller than the lower and short, the part of the face below the nose also seems unnaturally shortened.
Functional changes are also characteristic of mesial occlusion - speech and chewing are impaired.
Speech becomes lisp or burr, diction slurred. Biting and chewing food becomes problematic. The nasolabial folds become clearly defined, deep, the nose is extended, the size of the tongue is increased. When chewing, crunching may occur, lateral movement of the jaw in patients is difficult.
Diagnosis of Progenia
To diagnose mesial occlusion, a consultation with an orthodontist, a specialist in the correction of maxillary pathologies, is mandatory. He will not only conduct a visual examination and take anthropometry to assess the pathology, but also conduct functional tests to separate the true and false forms. For this purpose, bite wax rolls, tomography, radiography, orthopantomography are used. As an additional diagnosis, a myography of the masticatory and temporal muscles can be performed.
Diagnostic Jaw Models
Gerlach's method will reveal the ratio of segments according to a special formula, which is important for the choice of treatment with the removal of individual teeth in the lower jaw.
Pon's method - violation of the transverse dimensions of the dental arches with a mesial bite and clarification of their localization.
The Korkhaus method determines that the length of the anterior dental arch of the upper jaw is reduced compared to the lower jaw.
In order to choose a treatment for a mesial bite, it is necessary to establish the degree of ossification of the general skeleton and its front part on an x-ray. This is also important for predicting treatment outcomes. For this purpose, the patient’s brush is studied according to Björk.
Lateral radiography of the head is the most informative and often the main method for diagnosing a malocclusion.
The degree of severity of the pathology is assessed by occlusion of the bite of the bite, teleretgenography (TRG) in the lateral projection is an X-ray with the capture of the entire skull.
Complications of anomalies
Mesial occlusion is dangerous with such complications:
- migraine;
- dizziness;
- tinnitus;
- enamel is washed off early in the teeth of the upper row, because the load on them is increased;
- thinning of the bones of the skull;
- digestive disorders with irritation of the stomach, because the food is chewed poorly;
- diseases of the jaw joints and oral cavity - periodontal disease;
- spasms of the facial muscles;
- difficulties in oral hygiene;
- loosening and decay of teeth;
- tooth loss;
- difficulty in implant placement;
- aesthetic problems.
Treatment
Treatment of mesial occlusion is best started at the first sign. The success of therapy depends on the age of the patient, the cause of the anomaly, the degree of neglect and the correct implementation of all recommendations. In addition, treatment for success must be comprehensive:
- surgical intervention to change the structure of the dentition;
- myotherapy for the development of lagging elements of the lower part of the face;
- the use of orthodontic appliances - braces, mouth guards, plates, etc.
To begin with, they are determined with the age of the patient. If the growth of the bones of the mandible is not yet complete, you can try to slow down this process. Otherwise, they try to reduce its size.
Progenia treatment in young patients
For therapy, orthodontic devices are used - helmets with a chin sling attached to it with rubber traction, masks and clasp Frenkel activators.
In the early stages, wearing interchangeable devices is recommended, including dental trainers and mouth guards (tires).
Trainers are used more often because they act on the muscles by training them. That is, the cause of the defect is being eliminated. In such cases, the bite is leveled out more effectively.
Treatment of mesial occlusion in the milk bite (temporary) is to provide the optimum for the growth of the alveolar process of the maxillary bone. If the cause is a shortened frenulum of the tongue, having cut it, you can make it normal (plastic).
Try to restore normal chewing and swallowing. Hard food is recommended for this, if you have a bad habit of sucking, they all use standard or individual vestibular plates. They are elastic, hypoallergenic, made of silicone and perfectly switch the baby's attention. It is placed in the oral cavity, it does not allow pressure on the upper jaw, which occurs when objects are sucked in the mouth.
With myogymnastics they train the circular muscle of the mouth so that the lips begin to close properly and the child breathes through his nose.
Circular muscle exercises of the mouth are done with the help of the Dass activator. Also, the cutting edges of the upper and lower incisors, tubercles of the canines are often ground, with further massage of the alveolar process (this is part of the bone) of the upper jaw.
Massage is done for 2 minutes in the morning and in the evening. It helps in the end to properly close the incisors on both jaws.
The Bruckle apparatus is a corrective orthodontic device that has a basis with an inclined surface. When wearing around the clock for a month, the teeth begin to fully and correctly close, the bite is normal.
Treatment of progeny in schoolchildren
In addition to the above devices, a Frenkel regulator or Klammt activator of the third type is used, etc. The Frenkel apparatus is a metal wire frame to which plastic shields are attached. Are made individually. The design prevents soft tissues from growing around the teeth of the upper jaw.
If the devices do not give an effect, the treatment becomes the removal of some teeth on the lower jaw - this is in adults (premolars, fangs).
The most popular and effective treatment for mesial occlusion is the use of bracket systems. Their cost is from 35 to 300 thousand rubles. Children need to wear them for 1.5 years. Also, a good effect of such treatment was noted in adolescents.
Treatment of mesial occlusion in a removable bite (mixed bite - the simultaneous presence of removable and permanent teeth) is carried out by the same methods as with milk teeth.
In addition, the following are often used:
- Double Schwartz plate - well corrects mesial bite. She has a special sliding pin that tends to push the lower jaw forward.
- The use of activators also gives good results. The activator of Andresen-Goiplya and Vunderera are almost the same - they are used for milk and removable bite with mesial occlusion.
- Screw (pushers) Weise - set in the area of the front teeth. A screw is an integral part of a factory-made orthodontic apparatus. It can be regulated by the patient. When the screw is untwisted, the device moves mesially, and the mandibular part moves distally. With such artificial pressure, the contact moves correctly.
- Type 3 Frenkel function regulator - creates and maintains myodynamic balance in the jaws and helps eliminate morphological disorders of progeny.
Permanent Bite Treatment
Conservative treatment of mesial occlusion in adults is not always effective. For them, only two options are applicable: braces (mouth guards) or surgically.
In the period of a permanent bite, mainly fixed bracket systems are used. The best effect is achieved with an early start of treatment. Success is manifested in the alignment of the face and the normal position of the chin. The most effective therapy is observed in children under 12 years of age.
It is difficult to treat adult patients for a long time, since the dentition is already ossified and fully formed, therefore it is extremely difficult to undergo any changes. The duration of treatment can take from 3 to 5 years. The intervention of the surgeon most effectively helps with progeny.
In adult patients with mesial occlusion with a deep incisal overlap of the entire height of the upper crowns of the teeth, the prognosis leaves much to be desired. In these cases, they try to shorten the lower dental arch by removing some of the teeth on the lower jaw.
After conservative treatment, the results must be fixed, which is called retension. For this purpose, a fixed retainer is used - it is a metal structure in the form of a metal arch, which is attached to the inside of the teeth and maintains the position of the entire dentition.
With severe progeny, only the operational method of treatment is applicable. It becomes the only effective.
Operation
Usually, the teeth of the lower row are removed. These operations are quite expensive and often give complications (for example, damage to the trigeminal nerve).
With a large size of the lower jaw, before surgery, it is advisable to push forward the underdeveloped upper jaw or try to develop it. It always creates health problems for its owner. Then the reference point for surgeons is more accurate. This is the work of the orthodontist.
With a good result with the upper jaw, the patient may refuse surgery. In adults, the treatment time is always increased, they are phased.
Myogymnastics
Myogymnastics is used in dentistry not only to eliminate malocclusion, but also to prevent it. The goal of this gymnastics is to train certain muscles. Gymnastics gives the best result in children 4-7 years old.
How to do gymnastics
To get the effect of gymnastics, you need to follow some rules:
- Increase speed and repetitions only gradually.
- Muscle contract as much as possible.
- The pause between contractions should be the same in duration as during contraction.
- Doing gymnastics is necessary only to light fatigue.
Mesial bite exercises
With mesial occlusion, special gymnastics also helps, which is performed in the morning and evening, literally for 10-15 minutes. Repetitions of exercises 10 times. Positive results first appear after 3 months, and successful - after six months.
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The tip of the tongue needs to be pressed on the hard palate of the maxilla until a feeling of slight fatigue appears (3-5 minutes). Tilt your head back slightly, gently opening and closing your mouth. With your mouth closed, you should try to reach the back edge of the hard palate. With a drooping lower lip, pull it under the upper frontal teeth, then gently release it.
Prognathic prophylaxis
Prognathy can be corrected at any age, but the effect will be different. However, a woman needs to precede and carry out prophylaxis already during pregnancy. This is especially important in the first trimester, when the laying of the most important organs occurs.
Facial bones form by 7-15 weeks. Competent management of childbirth is necessary with incorrect presentation of the fetus - buttock, lower or transverse. This will help to avoid birth injuries.
It is better to breastfeed a newborn baby. Each feeding of the baby should last at least 20 minutes. Although the child eats up during the first 5-6 minutes, the remaining time is spent on him training the jaw muscles while sucking. If the breast is taken away, then to improve the sucking reflex, the child will suck on a finger or a pacifier.
Follow the baby’s manners and eradicate bad habits such as sucking lips, fingers, nipples, toys, etc. Dentists recommend giving the baby a nipple before teething, then gradually wean the baby from it.
It is also important that the child sleeps in the correct position - there should not be a high pillow, a hunched posture, or sleeping on his stomach. The correct posture with the exception of kyphosis, hardening of the child in order to prevent diseases of the ENT organs, colds with complications is important.
Gymnastics of the facial muscles for the purpose of prevention is selected by the doctor. With genetic etiology, this is ineffective.
conclusions
In mesial occlusion of the dentition, the causes are more often skeletal than dental. This usually applies to the upper jaw - it is either small or located behind. In the first case, they try to develop it for correction, in the second - pull it forward.
An attempt to restrain and slow down the growth of the lower jaw has practically no prospects, this is impossible in adults by physiology.
Surgical treatment of prognathia is carried out in cases where the cause is too large the lower jaw. To identify this, proper diagnosis is of utmost importance.