In simple terms, the correct bite in medicine and, in particular, in dentistry is the relative position of the teeth, which is optimal for the process of nutrition and articulation. Some researchers believe that most people have some kind of malocclusion, but serious problems because of this arise with rather gross pathologies of location, visible to the naked eye.
The nature of the bite is determined genetically, but it is also influenced by living conditions after birth: nutrition, vitamin and trace element levels, injuries and some infectious diseases. Let us consider in more detail under what cases and how to correct the bite in various cases.
Correct configuration of dentition
For the bite to be called correct, it must have the following characteristics:
- The presence of 28 dental units (in the presence of wisdom teeth – 32). The absence of eights is not a sign of a violation.
- The upper dentition covers the lower one by 1/3 of the height of the crowns, while the lower crowns are located at a slight inclination towards the oral cavity.
- The jaws are symmetrical.
- There are no noticeable interdental spaces, the organ enamel has no chips or cracks.
- The upper and lower premolars and molars close tightly, the chewing surfaces correspond to each other.
- The movements in the mandibular joint are not limited, the mouth painlessly opens to its maximum width. Biting off and chewing solid food is painless and effortless. The diction is not broken. Breathing through the nose is carried out freely, there are no chronic headaches, tension of the cervical muscles, bruxism, osteochondrosis of the cervical vertebrae.
These signs indicate that the teeth are fully performing their functions. In this case, there may be purely cosmetic defects that do not affect the quality of life. This is called a borderline state, and is not referred to as pathology.
Types of correct bite
Consider the main types of bites, called correct:
The most optimal variant of the configuration of the dentition, combining all the features listed above. It is rare enough.
The lower jaw (mandible) protrudes forward more strongly than in the first case, but the lower incisors are closed with the upper ones, and the movements in the jaw joint are carried out in full.
When the mouth is closed, the front teeth are closed by the cutting edges, without overlapping each other. This is a variant of the norm, but during life it can lead to damage to the enamel due to the high load during eating.
The upper and lower jaws protrude forward. At the same time, the dentition has a slight bias towards the lips.
The jaws are extended similarly to the biprognathic variant, but the chewing units are deflected towards the tongue. This option is also less common than the others.
There are a lot of people with disorders of the relative position of teeth – up to 90% in the population. Some minor deviations may not cause problems throughout life, but there is always a risk that an incorrect bite will provoke the development of more serious complications. Therefore, in most cases, dentists recommend doing the correction of the dentition.
Development of violations
In some cases, pathologies of the position of dental units are due to genetic characteristics.
There are five periods of bite formation. If during one of them any failure occurs, then this leads to the appearance of violations of the shape or position of the chewing organs, which persist for life.
- 1From six months – until the beginning of eruption, there are already rudiments in the jaw – tooth buds.
- 26 months – 3 years – temporary “baby teeth” partially erupt.
- 33-6 years – there is an active growth of the skeleton, including the maxillary and mandibular bones.
- 46-12 years old – mixed. In addition to continuing bone growth, the eruption of milk units is completed.
- 512-16 years – the growth rate slows down, the change of temporary teeth to permanent ones begins and ends.
Bite pathologies can occur due to improper bone growth, violations during eruption, or inconsistency of these processes.
If the bone is not growing fast enough, and the dental crowns have already appeared, and they are large, then they do not have enough space, and they are displaced.
If bone growth is ahead of schedule, diastases occur. In severe disorders, some types of teeth may not erupt at all.
Causes of bite pathology
The main factors leading to the disease:
- Features of feeding in the period before teething. In order for the baby to properly grow the bones of the facial skull, they must receive a load. This is facilitated by natural feeding. If, for some reason, the child ate without effort, the mandible does not develop enough.
- Lack of solid food after eruption.
- Injury in any of the periods, premature loss of milk units. This leads to a shift in adjacent organs, and disrupts the architecture of the bite.
- Heredity and genetic diseases (cleft palate, severe cleft lip, Down syndrome).
- Childhood habits – long thumb sucking, holding the hand under the cheek while sleeping, tilting the head back when breastfeeding or bottle feeding.
- Diseases of the upper respiratory tract, due to which nasal breathing is impaired. With a constantly open mouth, the chewing muscles tense and press on the alveolar arch, which makes it narrower, and the mandible can move back.
- Diseases of the thyroid gland with a drop in the level of its hormones.
- Periodic grinding of the jaws – bruxism.
- Violation of the metabolism of minerals – calcium, fluoride, or a small intake of them with food.
- Maxillofacial injuries.
- Causes of pathology in adults.
- In some cases, the disease can begin after the completion of tooth growth.
- Incorrect placement of dentures.
- Extraction of teeth.
- Facial injuries.
- Violations of the shape and position of the tongue.
- The beginning of the eruption of the third molars.
- Osteomyelitis, primary or secondary, violation of the mandibular joint.
- Raising the alveoli and tooth above the level of the rest of the row (Popov-Godon phenomenon).
Also, malocclusion in adults and the elderly may develop a deep or mesial variant of the pathology.
Due to the incorrect position of the units in the mouth, their closure is disturbed, due to which food is poorly absorbed, the tongue cannot move normally when speaking, diction defects arise, and an aesthetic defect occurs.
Types of violations
For what types of violations it is necessary to correct the occlusion, consider the main types.
Synonym for distal occlusion. The most common violation. It is characterized by a significantly protruding upper jaw and dentition. This can be due to both the overgrowth of the upper sections and the reduced lower jaw.
The upper sections also protrude, while the dentition does not close, forming a noticeable gap. Because of this, it is difficult for a person to bite off something, and chewing is also difficult. In some cases, breathing can also be difficult. With severe prognathia, the defect is also noticeable when the mouth is closed: the upper lip protrudes, and does not close with the lower one.
With the mouth closed, the crowns of the upper units overlap the lower ones by half or more. This often leads to accelerated erasure of enamel from them and the development of cracks or other defects.
At the same time, the lower part of the face appears smaller, and the lip turns outward.
The lower half of the bite is exposed forward. The upper lip is sunken, and the chin is pushed forward, it looks massive.
Incomplete closure of the dentition, leaving a gap, more often between the incisors, less often between the molars. The face thus looks elongated. This pathology is difficult to correct.
The lower jaw is constantly shifted to the left or right side and narrowed. The face is clearly asymmetrical. A gross violation that leads to serious complications: periodontal disease and tooth loss.
The teeth are misaligned with respect to the bone and grow out of place. This happens especially often if part of the organs is missing.
There are many more variants of violations than normal ones. This is due to the frequency of occurrence of pathology. Also, the teeth can be unequal in height, be turned around their axis, which is why very wide gaps between them are formed.
Because of this, a person has to make additional efforts when chewing, to strain the neck muscles. Children can start breathing through their mouths.
In most cases, a malocclusion can be noticed even without special education. As soon as there are suspicions that the child’s teeth are growing incorrectly, it is necessary to contact a pediatric dentist for examination and determination of treatment tactics.