There are a lot of dental diseases. Withstanding enormous daily stress and bacterial attacks, our teeth tend to gradually decay. There is also a disease such as complete absence of teeth in dental practice. It can be congenital or acquired. Today we want to tell you all about the causes, types and treatment of adentia.

What is it?

If we talk about real complete edentia, then this means a congenital developmental pathology. It is characterized by the absence of teeth, and sometimes their rudiments. Fortunately, this phenomenon occurs in isolated cases. More often it is necessary to treat partial absence of teeth - congenital or acquired.

This is not only an aesthetic defect. The pathology leads to serious dysfunction of the jaw apparatus, speech, and gastrointestinal tract. The consequence of an aesthetic defect is often a violation of social adaptation, decreased self-esteem and other psychological problems.

Types of edentia

There are several types of dental anomalies, each of which has its own characteristics. Let's take a closer look at them.

1. With partial primary adentia, only a few teeth are missing in the upper jaw or lower jaw. Most often, such adentia is diagnosed in children at the stage of the appearance of milk teeth. In most cases, their rudiments are not detected even on x-ray examination. Because of this, trema are formed - spaces between the teeth. Partial absence of teeth in a child can lead to insufficient jaw development. This form also appears in permanent dentition with the same symptoms. Overgrown teeth can shift, leading to malocclusion, and sometimes even the jaw becomes deformed.
2. Primary adentia with complete absence of teeth is a severe pathology with an unpleasant symptom. In medical practice it is rarely diagnosed. In this case, even the rudiments of both temporary and permanent teeth are absent. If measures are not taken, this anomaly can lead to severe defects in the development of the facial skeleton and oral mucosa.
3. Partial secondary adentia is diagnosed if several permanent teeth have been lost as a result of oral diseases or mechanical damage. Very often, the problem of partial secondary adentia arises as a result of carious processes. Although the bite and jaw are already fully formed by the time this occurs, partial secondary edentia can cause displacements in the dentition. This, in turn, leads to a decrease in bone tissue and various malocclusions.
4. Complete secondary adentia with tooth loss is typical for older people. It is quite rare. One of the options for solving the problem is implantation in the absence of teeth, which can be carried out by a good dental clinic with qualified surgeons.

Reasons for the development of pathology

Dental edentia can be caused by various reasons. For example, the primary form in most cases occurs as a result of various intrauterine pathologies that prevent the formation of tooth buds. We can also talk about hereditary diseases here. The exact reasons for the development of primary adentia have not been established. Partial or complete adentia of the secondary type can appear for a variety of reasons, most often of an indirect nature.

1. Carious processes. Is the most common cause. If left untreated, caries quickly destroys the enamel, developing into other diseases. For example, pulpitis may develop. In cases where the tooth can no longer be saved, the doctor has no choice but to resort to its removal. Therefore, it is so important to begin treatment of carious processes at the first manifestations.
2. Partial edentia may be a consequence of other oral diseases. This includes periodontitis and periodontal disease. In the absence of high-quality and timely treatment, these diseases can also lead to loss of teeth in the upper or lower jaw.
3. Injuries. Both teeth and their rudiments can suffer from mechanical damage. This leads to tooth loss or the fact that it does not fully develop.

All these indirect reasons can result in partial or complete adentia, so it is necessary to pay enough attention to your teeth and promptly treat them. Dental problems are not only a matter of aesthetics, but also a serious factor that negatively affects your overall health.

Consequences of edentia

Clinical manifestations of the disease depend on its form and severity. Let's look at the main problems you may encounter:

• with complete edentia, deformation of the facial skeleton may be observed;
• the person has difficulty chewing food;
• speech therapy problems – difficulties with pronouncing sounds;
• dysfunction of the temporomandibular joint;
• diseases of the gastrointestinal tract as a result of poor quality chewing of food;
• even partial absence of teeth can affect a person’s psychological state;
• formation and deformation of bone tissue.

Diagnosis and treatment

Complete and partial adentia are diagnosed very simply. To make a preliminary diagnosis without specifying the reasons, a visual examination by a specialist is sufficient. The remaining data is obtained by performing an x-ray examination. An X-ray should be performed if primary adentia is suspected, as it allows us to identify the presence or absence of tooth buds. For the same purpose, orthopantomography is performed. Additionally, it allows you to study the characteristics of bone tissue and teeth.

Complete or partial absence of teeth will be treated according to different schemes. At the same time, the secondary type of the disease is much easier to treat than the primary one, due to the fact that there are no hereditary causes. However, both types are treated using orthopedic techniques.

1. Treatment of partial edentia is carried out using fixed bridges and removable laminar dentures. That is, the main method of treatment is prosthetics and dental implantation. The fewer teeth are missing in a row, the easier the prosthetics are. If at the same time there are pronounced malocclusions, then orthodontic structures are necessarily used.
2. In some cases, you can do without prosthetics. For example, if a person lacks two teeth in the upper row and one in the lower. In this case, it is enough to remove one tooth from the bottom row to achieve an even distribution of the load on the jaws. Partial adentia is eliminated quickly and with minimal discomfort for the person.
3. Complete secondary adentia is treated only by installing removable or permanent dentures. In the second case, the installation of implants with complete edentia is first required to create support. Elderly people are usually recommended to install removable plates - for elderly patients this is the best option.

In most cases, treatment gives good results, which allows a person to completely forget about the problem and return to normal life. However, sometimes difficulties arise that significantly complicate the prosthetic process:

• some pathologies of bone tissue can lead to poor fixation of prostheses;
• allergic reactions to polymers and other denture materials.

Modern dentistry can solve almost any problem with teeth and even restore them if they are completely missing. Therefore, if you have had to deal with adentia, you should not isolate yourself and consider your problem insoluble - it is better to hurry up and contact a good clinic, where you will be offered a competent treatment plan.

There are different methods of dental prosthetics. The final video is dedicated to this topic, in which an experienced dentist will tell you about the most common types of prosthetics. You can be sure that the highest level of development of dentistry guarantees a solution to any of your problems.

The term “edentia” is not the most common in dentistry, so not every patient understands what we are talking about on the first try. The phenomenon of edentia - congenital or acquired absence of teeth - is not so rare. Complete edentia (the absence of all teeth) is rare, but partial (with the loss of several) is a common occurrence. Should edentia be treated or can it be considered a cosmetic defect?

What is edentia

Adentia is the complete or partial absence of permanent or baby teeth. There are several types of edentia:

• full;
• partial;
• primary;
• secondary.

If you analyze this list, you can see the pattern of classification according to the principle of appearance - primary (the second name is congenital) and secondary (in another way - acquired) and according to the type of prevalence (complete or partial). The causes of adentia are not fully understood. It is believed that it occurs after the resorption of the follicle, which occurs under the influence of general diseases or inflammation.

Edentia of permanent teeth can appear as a complication for milk teeth, especially if the latter were not treated on time and with poor quality. Doctors do not rule out a hereditary factor, problems in the endocrine system, as a result of which deviations occur during the formation of tooth germs. In most cases, in the presence of edentia, patients may experience improper formation of nails, hair and other organs of actodermal origin.

There is a pattern in the absence of some permanent teeth - lateral incisors, lower premolars, wisdom teeth. According to statistics, dentists do not observe second incisors in 0.9%. The rudiments of the second lower premolar are absent in 0.5% of children. The reasons for this phenomenon are explained by the fact that the masticatory apparatus in modern conditions does not have such a serious load as in its distant ancestors. Evolution has changed the size of the jaw, the number of rudiments of permanent teeth, since there is no place for them in the changed jaw - reduction of the jaw leads to reduction of teeth.

With a symmetrical incomplete number of teeth, the role of hereditary factors is great. There are cases when all the tooth germs are present, but some of them do not erupt, remaining retained in the alveolar bone. This fact is confirmed by radiography. In primary occlusion this phenomenon is rare. An impacted tooth can create many problems for the jaw: displacement of adjacent teeth, deformation of adjacent roots. Often such a tooth causes neuralgic pain and can serve as a source of focal infection.

In childhood, it is necessary to take into account the likelihood of teeth erupting late, sometimes beyond the physiological period. A tooth may be delayed due to lack of space in the dentition. Timely orthodontic intervention is important here.

True adentia must be distinguished from retention - delayed growth of a tooth after it has been placed. Retention can be caused by vitamin, hormonal disorders, or hereditary factors. Typically, impacted teeth are displaced. Sometimes, even after decades, they still erupt. This process can be stimulated by orthopedic intervention. Retention causes deformation of the jaw, changes in the position of neighboring teeth, pressure from a displaced tooth on the neighboring root causes pulp atrophy, suppuration, root resorption (destruction of its tissues), so it is important to control this process.

Primary full

Complete primary adentia is a very serious anomaly, which, fortunately, is very rare. It occurs in the bite of baby or permanent teeth. The patient is completely deprived of the rudiments of all permanent teeth. This condition inevitably provokes violations of facial symmetry. At the same time, the alveolar processes of both jaws develop incorrectly. The mucous membrane of the oral cavity is pale and dry.

When baby teeth are edentulous, their rudiments are completely absent; by palpating the jaw, this is easy to diagnose. On the radiograph, the rudiments of baby teeth are completely absent, and the jaws are underdeveloped, which causes a severe reduction in the lower part of the face.

Edentia of permanent teeth is usually detected when milk teeth are replaced with permanent ones. On the x-ray, the doctor observes the absence of the rudiments of permanent teeth, the pulling of the lower jaw towards the upper, with subsequent asymmetry of the face.

Primary partial

Primary partial adentia is much more common than complete adentia. In the dentition with this form, several or one primary or permanent teeth are missing. On the radiograph there are no rudiments of missing teeth, but gaps appear between the erupted teeth - trema. If a significant part of the teeth is missing in the dentition, then the jaw is formed underdeveloped.

Partial edentia can be symmetrical or asymmetrical. With symmetrical edentia, there are no teeth of the same name on the right and left in the dentition - for example, the right and left incisors. With asymmetrical – there are no teeth of different names on different sides.

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Secondary full

Secondary adentia has another name - acquired. In the secondary form, teeth in the dentition are completely absent, both on the upper and lower jaws. Secondary adentia occurs in both permanent and baby teeth. This phenomenon occurs after tooth loss or extraction.

With complete secondary edentia, the patient’s mouth has no teeth at all, so the lower jaw moves closer to the nose, and the soft tissues of the mouth area noticeably recede. With complete secondary adentia, the alveolar processes and the body of the jaw atrophy. The patient is unable to bite or chew food and is unable to clearly pronounce sounds.

Secondary partial

Partial secondary adentia is the more common form. With this disease, several (or one) primary or permanent teeth are missing from the dentition. If there is insufficient tooth enamel, the hard tissues of the tooth are worn away, causing hyperesthesia. The disease makes it difficult to eat hot or cold food, creating a habit of liquid food that does not need to be chewed. In the photo - complete and partial edentia, edentia in children.

Symptoms of edentia

The symptoms of adentia are simple - complete or partial absence of teeth. In addition to direct symptoms, there are also indirect ones:

• reduction of one or both jaws;
• retraction of the soft tissues of the oral part of the face;
• atrophy of the alveolar processes;
• formation of a network of wrinkles around the mouth;
• atrophied muscles in the mouth area;
• dullness of the angle of the jaw.

With partial edentia, a deep (distorted) bite is formed. The teeth gradually shift towards the missing ones. In the area where there are no antagonist teeth, the dentoalveolar processes of healthy teeth lengthen.

Diagnosis of edentia

Diagnosing edentia is not difficult. When examining the patient’s oral cavity, the dentist notes the complete or partial absence of teeth in a row. An X-ray examination of both jaws is required, especially in cases of primary adentia, since only in the image can one see the absence of the rudiments of permanent or baby teeth.

When diagnosing adentia in children, a panoramic X-ray of the jaw is taken - it is this that allows one to determine the absence of tooth buds, the structure of the roots of the teeth and the bone tissue of the alveolar process.

When diagnosing, it is necessary to exclude factors that do not allow urgent treatment. The dentist highlights the following points:

• the presence of unremoved roots covered with mucous membrane;
• the presence of exostoses;
• the presence of tumors and inflammation;
• the presence of diseases of the oral mucosa.

After the final elimination of all provoking factors, prosthetics can begin.

Treatment of adentia

The most effective method of treating adentia is orthopedic. The doctor draws up a treatment regimen based on the degree of atrophy of the alveolar processes and tubercles. When treating primary adentia, depending on the patient’s age, the patient is registered at a dispensary and a pre-orthodontic trainer is installed.

In case of partial primary adentia in children, it is necessary to stimulate proper teething to prevent jaw deformation. When the seventh permanent teeth erupt, the dentist explores options for prosthetics for missing teeth:

• prosthetics with metal-ceramic crowns and inlays;
• production of an adhesive bridge;
• implantation of missing teeth.

Treatment of primary adentia in children with the help of prosthetics is carried out by prosthetics from the age of 3 years. Such children should be under the constant supervision of a specialist - due to the pressure of the prosthesis, there is a danger of impaired jaw growth in the baby.

When treating secondary complete adentia, the dentist restores the functionality of the dentofacial system, preventing the development of complications and pathologies, and after restoration, performs prosthetics using removable plate dentures. When treating secondary adentia, it is important to eliminate the cause of the pathological process that provokes adentia.

In case of complete edentia, preliminary dental implantation is performed.

When treating adentia with prosthetics, complications are possible

• disruption of normal fixation of the prosthesis due to jaw atrophy;
• allergic reaction to denture material;
• inflammatory process;
• formation of bedsores.

An important point is psychological assistance to patients experiencing psychological discomfort from tooth loss.

Consequences of edentia

• Adentia is a complex dental disease, and without proper treatment, the patient’s quality of life can significantly suffer. With complete edentia, speech impairment occurs and it becomes inarticulate. The patient is unable to chew or bite off solid food. Poor nutrition leads to gastrointestinal problems and vitamin deficiency.
• In the absence of teeth, the temporomandibular joint does not function properly, which often leads to the development of inflammatory processes.
• It is impossible not to take into account psychological discomfort, a decrease in the patient’s social status, and self-esteem. All this provokes regular stress and the occurrence of nervous disorders.

Edentia must be treated without fail, and without much thought.

Adentia - symptoms and treatment

What is edentia? We will discuss the causes, diagnosis and treatment methods in the article by Dr. Alexander Sergeevich Gorozhantsev, an orthopedic dentist with 22 years of experience.

Definition of disease. Causes of the disease

Edentia is a pathology characterized by the absence of one or more teeth. It is also possible to completely lose the dentition - complete edentia.

The hereditary origin of this disease accounts for 63.1% of the total number of people with edentia. Most researchers have come to the conclusion that the frequency of manifestation of this anomaly depends on environmental factors: geography of residence, climatic conditions, ecology and others.

Based on the reasons for their occurrence, there are two forms of adentia:

• primary (true) - makes up 0.9% of the number of people seeking dental care;
• secondary (acquired).

With primary adentia from birth there is no germ of a temporary or permanent tooth. This is due to the incorrect formation of the rudiment itself. Thus, according to the research of N.V. Bondarets, 92.46% of patients with partially edentulous primary teeth lacked the rudiments of corresponding permanent teeth.

Secondary adentia occurs due to trauma to the germ of an unerupted tooth at an early age, as well as inflammatory diseases and injuries to erupted teeth.

Damage to the embryo in childhood often occurs due to the child’s inattention and high activity, curiosity and carelessness. These factors can lead to a root fracture, impacted tooth, or complete dislocation.

Also, in children who undergo chemotherapy during the formation of tooth buds, aplasia of these buds often occurs.

The lesion occurs when the rudiments of permanent teeth are involved in the inflammatory process that occurs as a complication of periodontitis in temporary teeth.

As an adult The causes of edentia in permanent teeth are no less varied. These include:

• loss of a tooth/teeth as a result of inflammation of the periodontium and hard tissues of the tooth and jaws;
• dystrophic periodontal lesions (gingivitis, );
• various injuries of the dentofacial apparatus(irrational orthopedic treatment, mechanical and chemical injuries);
• chronic diseases (for example, and);
• bad habits (smoking, chewing hard objects, etc.).

If you notice similar symptoms, consult your doctor. Do not self-medicate - it is dangerous for your health!

Symptoms of edentia

The main symptom of both primary and secondary adentia is the displacement of teeth in the dental arch after the formation of a defect (absence of teeth), which leads to a change in the occlusal curve (a conditional line passing through the points of closure of the teeth).

The deformation of the dental arch is based on a single process of bone restructuring after the loss of normal functional load, i.e. after tooth loss. This process is known as the Popov-Hodon phenomenon. Over time, bone restructuring progresses, affecting the proportions of the face.

Without proper treatment for complete edentia, the lips recede, the nasolabial and chin folds become pronounced, the corners of the mouth droop down, a double chin appears, the lower jaw decreases, and wrinkles form on the neck. In this case, children most often develop the dentoalveolar form of the Popov-Godon phenomenon: underdevelopment of the alveolar process of one or both jaws gives the child’s face a typical senile expression inherent in edentulous adult patients.

Even with the loss of one or three teeth, chewing function is impaired. And although the patient himself may consider the difficulties associated with chewing to be insignificant, the changes described above still begin to occur in the dental system.

Impaired closure of teeth leads to pathological changes in the temporomandibular joint, a common symptom of which is Costain syndrome, which has a variety of clinical manifestations:

• dizziness;
• noise in the ear and its congestion;
• impaired closure of the dentition and movement of the temporomandibular joint;
• pain in the neck area.

Adentia also manifests itself as a violation of speech production, especially with the loss of frontal teeth, which play the most important role in creating sounds.

Pathogenesis of adentia

The pathogenesis of the pathology lies in the initial violation of the formation of the tooth germ - the resorption of its follicles (a kind of protective mechanism) under the influence of general, toxic diseases and inflammatory processes as a result of complications of periodontitis of primary teeth.

In addition, there are hypotheses that congenital absence of teeth can develop as a result of errors in the laid down hereditary program for the emergence and development of dental tissues.

In domestic and foreign literature, many researchers have analyzed chromosomal errors, the presence of which can lead to disruption of the formation of the tooth germ and the development of the dentofacial system. These include:

• chromosomal abnormalities in certain areas and gene mutations;
• joint action of many genes and environmental factors;
• disturbances of mineral metabolism.

Sometimes primary adentia is a characteristic sign of another systemic disease. Thus, cases of concomitant single or systemic adentia are described with:

J. Parmanand in 2003 recorded the absence of tooth rudiments in cleft palates and lips - cleft palate and cleft lip. Moreover, according to R.R. Shakirova, primary adentia of permanent teeth in children with this anomaly was observed more often (34.3%) than adentia of primary teeth (16.8%).

Classification and stages of development of edentia

According to the ICD-10 classification, the following alphanumeric codes are assigned to different forms of edentia:

• K00.00 Partial edentia:

1. hypodontia - absence of several teeth;
2. oligodentia - congenital absence of most teeth;

• K00.01 Completely edentulous;
• K00.09 Unspecified edentia.

According to the authors I.M. Rasulov and M.G. Budaichiev, this classification should be clarified or revised completely, since unspecified adentia is, rather, not a specific diagnosis or condition, but only a situation in which the doctor was unable, for various reasons, to determine the factor in the occurrence of the disease.

As mentioned earlier, for reasons of appearance, primary and secondary adentia. It is necessary to establish the cause-and-effect relationships that led to the pathology to accurately select a treatment method.

Based on the volume of the defect, partial and complete edentia are divided.

Depending on how many teeth are missing, three groups of defects are distinguished:

• small - one tooth is missing;
• medium - 2-3 teeth missing;
• large - more than three teeth are missing.

Most often in practice, the classification of dental defects is used, which was introduced by the American dentist E. Kennedy. He divided edentulism into four classes:

• Class I - loss of chewing teeth on both sides;
• Class II - defect of the dentition on one side;
• Class III - tooth defect on one side in the presence of distal (lateral) support;
• Class IV - absence of teeth in the frontal area of ​​the dentition.

All of the above systematization options allow us to cover a wide variety of dentition defects, which facilitates diagnosis and planning of orthopedic treatment.

Complications of edentulism

Complications of adentia are psychosocial, neurological, dental, and sometimes systemic in nature.

In the complete absence of teeth, atrophy of the alveolar processes occurs first. This leads to a violation of the aesthetics of the smile, as a result of which people with this disease develop psychological problems.

When there is edentulism in one jaw, the antagonizing (opposite) teeth in the dentition are crowded or piled on top of each other. In this case, individual teeth are located outside the dentition or.

Changes are observed in the composition of oral fluid. These disorders create favorable conditions for the occurrence of diseases of the dental system, which, at times, the body’s adaptive mechanisms are no longer able to cope with:

• the rate of saliva secretion decreases;
• the reaction of the environment changes;
• the amount of protein in the oral fluid decreases;
• indicators of antibacterial and antiradical protection change.

In 100% of cases of secondary adentia, macroglossia occurs over time, i.e., enlargement of the tongue: its microvascular bed undergoes changes.

The periodontium of the remaining teeth experiences functional overload, in particular, the endurance of the periodontium of the teeth limiting the defect decreases. This leads to the formation of pathological bone pockets, atrophy of the dental alveoli and localized gingivitis.

Violation of the closure of the dentition causes pathological changes in the structure of the temporomandibular joint: the movements of the articular heads are limited, the histological structure of the tissues changes.

The mutual influence of the structures of the masticatory apparatus creates the prerequisites for the formation of neurological phenomena. One of the most diverse manifestations is Costen's syndrome. It may be accompanied by:

• pain, mainly in the parotid region;
• congestion in the ear and hearing loss;
• dizziness;
• violation of taste sensitivity.

Due to the lack of chewing teeth and insufficient mechanical processing of food, disorders associated with digestion are formed - stomach ulcers.

With all this, experience shows that increasing the medical literacy of the population reduces the number of cases of possible complications, which obviously leads to an increase in the level of dental health of the population.

Diagnosis of edentia

Diagnosis of edentia is not a problem, since the disease is detected during a routine dental examination of the patient.

When making a diagnosis, it is important to determine the presence or absence of a tooth germ. This can be determined by orthopantomographic examination. The interpretation of data obtained from computed tomography and the study of plaster models of jaws are also carried out.

Normally, the eruption of the first milk teeth begins at 6-8 months, and the appearance of permanent teeth in place of the fallen milk teeth occurs at 7-13 years. If new teeth do not appear in infants by 11-12 months, and the permanent tooth does not replace the baby tooth a month after falling out, then it is recommended to consult a dentist and take a targeted x-ray of the problem area. This will allow you to exclude or confirm edentia.

Early diagnosis of adentia is based on early diagnosis of diseases that are usually accompanied by congenital absence of teeth:

• diagnosis of anhidrotic ectodermal dysplasia is made by a geneticist based on DNA testing and hereditary history;
• Early detection of Down syndrome is possible even before birth by analyzing amniotic fluid and screening the mother's venous blood for the presence of certain markers of the disease.

Treatment of adentia

Treatment tactics are chosen by the dentist based on a thorough examination.

With partial edentia Traditional bridge, clasp, plastic and nylon plate prostheses are used.

The most reliable, aesthetic and promising treatment method is implant prosthetics. One of the latest developments in this area is physiological dental implants printed on a 3D printer. Thus, at the International Dental Exhibition in 2017, they demonstrated a model of a dental implant printed on a 3D printer, which completely replicated the natural shape of the tooth.

Experience with traditional dental implants over the years has proven their long service life. An undoubted advantage is that there is no need to remove healthy tissue from adjacent teeth (unlike traditional bridge prosthetics).

With complete absence of teeth preference is given to removable and fixed prosthetics supported by implants. Progressive atrophy of the alveolar ridges of the jaws, associated with the lack of adequate chewing load, complicates the use of removable plate dentures, especially in the lower jaw.

The greatest difficulty in treatment is caseschildhood edentia: growth and development of the dental system, which continues after the birth of a child, limits the use of implants.

The main issues that arise when using dental implants in children and adolescents are:

• the effect of implants on the growth and development of individual parts of the jaws, the jaw as a whole and the dental system;
• the influence of growth on the position of implants and changes associated with this.

After the eruption of permanent teeth, the jaw bones stop growing, so the use of dental implants is possible in children with all erupted permanent teeth (except for third molars - wisdom teeth).

Thus, in 1989, the DGZMK organization came to the conclusion that the use of dental implants in children under 15 years of age may pose a danger to the normal development of the jaws. However, in some situations, the use of dental implantation is the only possible method of treating adentia (for example, with a pathology such as ectodermal dysplasia). Therefore, in order to competently assist such young patients, the doctor needs to know the principles of jaw growth and development and understand the dynamics of the relationship between the implant and the developing jaws.

Forecast. Prevention

The success of edentulous treatment directly depends on the quality of diagnosis when choosing a treatment method. Prevention and elimination of concomitant pathologies is an important task on the path to patient rehabilitation.

In general, regardless of age and severity of the lesion, today there are all the necessary tools to minimize the phenomena of atrophy and the appearance of concomitant pathologies. With proper use of these tools for eliminating edentia, the prognosis will be favorable.

In children and adolescents, a successful outcome of edentulous treatment can be indicated by the proportional development of the bones of the facial skull, primarily the alveolar ridges and bodies of the upper and lower jaws.

In adulthood, the primary task is to maintain the height of the alveolar ridge, even if it is lost, modern methods of reconstructive surgery can restore the physiological structure of the dental system.

Restoration of chewing and articulation functions is possible in full and will indicate the success of the treatment. An important indicator is also the restoration of homeostasis (self-regulation) of the oral cavity.

Prevention of edentia is to prevent the occurrence of caries and other damage to the hard tissues of teeth, periodontal diseases and diseases associated with the loss of jaw bone tissue (malignant neoplasms, osteoporosis, osteonecrosis, etc.).

The main preventive measures look like this:

• regular and high-quality dental and oral hygiene;
• systematic examination by a dentist;
• early treatment of dental diseases;
• rational nutrition.

Prevention is carried out at the local and general levels.

The use of toothpastes containing fluoride (excluding populations living in areas with high concentrations of fluoride in water) increases the resistance of enamel to caries, especially when using toothpastes with amino fluoride. During secondary mineralization of enamel - the period of “maturation” of enamel for 3-5 years after teething - such pastes should be used in the maximum safe concentration.

Preventive filling of permanent teeth minimizes the risk of caries in the fissures (recesses) of teeth.

However, the most important thing in the prevention of dental pathologies is proper nutrition of the mother during pregnancy.

References

1. Bondarets N.V. Dental rehabilitation of children and adolescents with congenital partial absence of teeth: abstract of thesis. dis. ...cand. med. Sci. - M., 1990. - 25 p.
2. Gioeva Yu.A., Ivanov S.Yu., Kvantaeva M.V. Rationale for complex treatment of patients with complete or partial adentia complicated by upper micro- and/or retrognathia // Orthodontics. - 2007. - No. 3. - P. 34-37.

Many people don’t even know what this dental disease is. But those who have encountered this experience what happened as a serious problem that significantly reduces the quality of life. Edentia – this term refers to the absence of teeth. Complete edentia means that a person has no teeth at all. There is not a single tooth in either the top or bottom row.

Why does this happen, and how to live with this disease?

Symptoms and development of complete edentia

The disease can be either congenital or caused by various factors. Symptoms: missing teeth. In rare cases of abnormal development, the baby's teeth do not erupt because dental tissue was not formed when he was in the womb.

The disease is rare. At the stage of formation of tooth buds, a genetic anomaly occurs that stops their development. As a result, baby teeth do not erupt and permanent teeth do not grow.

Important! If a baby has not erupted a single tooth at the age of 12 months, this is a reason to visit a doctor.

Complete congenital adentia entails global disturbances during the formation of the facial skeleton.

1. The gnathic (lower) part of the face is significantly reduced.
2. The face is formed reduced in height.
3. The upper lip is shortened, but at the same time the upper jaw hangs over the lower jaw (supramental fold), since the lower part is disproportionately reduced.
4. The palate is flat and the jaws are underdeveloped.
5. The muscles around the mouth are atrophied.

Upper jaw - completely edentulous

The cause is a hereditary disease called ectodermal dysplasia.

By the way. The rudiments of both milk and permanent teeth are formed in the embryo while it is in the mother’s womb. Baby teeth form in the seventh week of pregnancy, permanent teeth in the 17th week.

In addition to these signs, the patient has modified skin - it is dry and wrinkled. Mucous membranes are dry and pale. There is also no hair on the eyebrows, eyelashes, or sparse hair on the head.

Secondary adentia

The result with this disease is the same as with the primary one - the absolute absence of teeth. But the disease occurs during life. A child is born with normal dental buds. Teeth erupt on time and are formed according to medical standards. But then, due to dental diseases or mechanical injury, he loses all his teeth. This can happen both in childhood (baby teeth) and in adulthood (with a permanent bite).

By the way. The higher a person’s age, the more likely he is to encounter secondary complete edentia. Statistically, up to 50 years of age, the disease is recorded in 1% of the population; at 60 years of age, 5.5% already suffer from secondary adentia; at the age of over 60 years, the disease is diagnosed in 25% of patients.

Edentia is a common occurrence in old age

How to treat

Of course, living with such an illness is not easy. But there is only one treatment method - prosthetics. It is advisable to install orthopedic prostheses, removable or fixed, as early as possible. For primary adentia - as soon as the child reaches three years of age. In secondary cases, immediately after tooth loss.

By the way. If edentulousness is not treated, the consequences can be very serious. Not only the vital functions of the entire organism are disrupted, but also the psychological well-being of a person.

Consequences

This disease causes serious disturbances in speech development (slurred pronunciation). Also, with edentia, due to the inability to perform biting and chewing functions, patients have to eat liquid or creamy soft foods. This cannot but affect the functioning of the digestive system, which is disrupted. It also reveals a lack of many nutrients that do not enter the body from food.

By the way. Due to the absence of teeth, problems with the temporomandibular joint arise. Its normal functioning is disrupted, which leads to various diseases.

In addition to medical problems, patients experience psychological difficulties. Social status decreases; he experiences psychological discomfort during communication and any communication. He often suffers from phobias, experiences stress, nervous system disorders, and is in a state of depression.

Prosthetic methods

In the treatment of this disease, various methods of prosthetics are used to return the patient to the functions that teeth should perform.

Table. Description of prosthetic methods for edentia

Important! When using prosthetics in young children diagnosed with congenital adentia of the first degree, there is a risk of stopping the growth of the jaw and its improper formation due to the fact that the prosthesis will put pressure on the jaw mechanism.

Symptoms and development of partial edentia

A primary or secondary defect, called partial edentia, is characterized by the absence of not the entire dentition, but only some units. This disease can also be congenital or acquired during life. It occurs more often than the full form, and in dental practice it stands alongside other anomalies, such as hyperodontia (excess teeth) and hypodontia (fewer teeth than normal).

By the way. The primary partial form of the disease is diagnosed in 1% of pediatric patients, and the secondary form is diagnosed in 75% of patients over 60 years of age.

If complete loss of teeth is a real life catastrophe, then partial loss is not perceived in society as something threatening to health and disrupting the normal course of life. Patients do not rush to the dentist to cure caries or get rid of chronic periodontal disease. As a result, they go to the surgeon and pull out the damaged teeth one by one.

Important! The absence of even a few teeth in the jaw for a long time leads not only to impaired aesthetics of the dentition, but is a prerequisite for pathological changes in the entire dental system, appearance, gastrointestinal tract, and psychological disorders.

Signs

The main symptom is a lack of teeth in a row or both rows. If this is observed for a long time, there are spaces between the teeth (empty spaces) that tend to be filled by the growing teeth nearby. They gradually shift towards three, sometimes even closing there. There is a disruption in the development of the jaw, a change in the bite and facial relief.

The teeth that are in the mouth can be highly crowded, protrude from the dentition, grow on top of each other, and are often impacted (do not erupt from the gums).

Consequences

Since the teeth are constantly in motion (shifted to the side), increased stress is placed on them during the chewing process. There is no stress placed on the empty areas of missing teeth. As a result, destruction of the jaw bone is observed.

Important! The presence of three and incorrect placement of the remaining teeth in the row can cause local chronic gingivitis.

Complications may also occur in the form of:

• pathological abrasion of dental tissue;
• difficult and painful closing of the jaws;
• hyperesthesia;
• formation of bone pockets and voids in the gum tissue;
• dislocation of the jaw joint.

The shape of the facial oval changes and becomes deformed in the jaw area. Nasolabial folds are more pronounced. The corners of the mouth droop. Lips and cheeks “sink.”

People with partial edentia often have gastritis and ulcers due to nutritional problems that arise as a result of teeth not fully fulfilling their chewing purpose. And it is almost certain that a person who has lost several teeth will experience social discomfort and lower self-esteem.

Diagnosis of partial edentia

In diagnosing this disease, the experience and knowledge of a variety of specialists in the field of dentistry is used: orthodontists and therapists, orthopedists and surgeons, periodontists and implantologists. Here, a visual examination is not enough, as is the case with the full form of the disease, so radiography, computed tomography, and orthopantomography are performed.

An X-ray will not only reveal missing teeth, but also detect the absence of their rudiments, and will also show the roots that are located in the gum tissue, unerupted (impacted) teeth, tumors and inflammation.

How to treat

The treatment is the same as for the diagnosis of complete adentia - orthopedic. The only difference is in the methods of prosthetics. In case of partial tooth loss, implantation may not be necessary - prosthetic structures are installed on the remaining teeth.

Both removable and non-removable prosthetic designs are used. The choice is made by an orthopedic dentist, taking into account the wishes of the patient, his anatomical features, the degree of the disease and income level.

By the way. Your own, carefully healed teeth can be used to support prosthetic structures. It is possible to install implants on empty spaces with a crown covering them.

Children begin to be treated for congenital partial edentia from the age of three. Prosthetics are performed using a partially removable prosthesis of a plate design. And only after the completion of the formation of the dentition, when the patient turns 16 years old (by this time all permanent teeth have been formed, except for the third molars, which have not even erupted yet), can the removable structure be replaced with a fixed bridge prosthesis. Implants can only be installed in patients over 18 years of age.

Prevention of edentia

As for the congenital form of the disease, preventive measures to ensure that the child is born with normally formed tooth buds should be taken by his mother during pregnancy.

1. Ensuring a favorable course of pregnancy.
2. Creating conditions for intrauterine development.
3. Elimination of all, even potential risks.

If a newborn child experiences a long delay, which is six months or more longer than the required time for teething, you should contact a pediatric dentist.

Partial acquired adentia can be prevented by timely contacting a dentist and eliminating any dental problems that have arisen. It is also necessary to observe hygienic measures for caring for the oral cavity.

In case of tooth loss or extraction, it is necessary to carry out prosthetics as soon as possible to restore the dentition and to avoid the development of adentia. study at the link.

Video - Complete edentia

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Edentia(adentia; a - a prefix meaning the absence of a characteristic, corresponds to the Russian prefix “without” + dens - tooth) - the absence of several or all teeth. There are acquired (as a result of disease or injury), congenital hereditary adentia.

In the specialized literature, a number of other terms are used: dentition defect, absence of teeth, tooth loss. Partial secondary adentia, as an independent nosological form of damage to the dentofacial system, is a disease of the dentition or both dentitions, characterized by a violation of the integrity of the dentition of the formed dentofacial system in the absence of pathological changes in the remaining parts of this system.

When part of the teeth is lost, all organs and tissues of the dental system can adapt to a given anatomical situation due to the compensatory capabilities of each organ of the system. However, after tooth loss, significant changes may occur in the system, which are classified as complications. These complications are discussed in other sections of the textbook.

In the definition of this nosological form, next to the classical term “edentia” there is the definition “secondary”. This means that the tooth (teeth) is lost after the final formation of the dentoalveolar system as a result of disease or injury, i.e. the concept of “secondary adentia” contains a differential diagnostic sign that the tooth (teeth) has formed normally, erupted and for some period functioned. It is necessary to highlight this form of lesions of the system, since a defect in the dentition can be observed when the rudiments of teeth die and when eruption is delayed (retention).

Partial adentia, according to WHO, along with caries and periodontal diseases, is one of the most common diseases of the dental system. It affects up to 75% of the population in various regions of the globe.

An analysis of the study of dental orthopedic morbidity in the maxillofacial area according to the data of referrals and planned preventive sanitation of the oral cavity shows that secondary partial adentia ranges from 40 to 75%. The prevalence of the disease and the number of missing teeth correlate with age.

In terms of frequency of removal, the first permanent molars occupy the first place. Less commonly, anterior teeth are removed.

Etiology and pathogenesis

Among the etiological factors causing partial adentia, it is necessary to distinguish between congenital (primary) and acquired (secondary).

The causes of primary partial adentia are disturbances in the embryogenesis of dental tissues, as a result of which there are no rudiments of permanent teeth. This group of reasons also includes disruption of the eruption process, which leads to the formation of impacted teeth and, as a consequence, to primary partial adentia. Both factors can be inherited.

The most common causes of secondary partial adentia are caries and its complications - pulpitis and periodontitis, as well as periodontal diseases - periodontitis. In some cases, tooth extraction is caused by untimely treatment, resulting in the development of persistent inflammatory processes in the peri-apical tissues. In other cases, this is a consequence of improperly administered therapeutic treatment.

Sluggish, asymptomatic necrobiotic processes in the dental pulp with the development of granulomatous and cystogranulomatous processes in the peri-apical tissues, the formation of a cyst in cases of a complex surgical approach for resection of the root apex, cystotomy or ectomy are indications for tooth extraction. Removal of teeth treated for caries and its complications is often caused by chipping or splitting of the crown and root of the tooth, weakened by the large mass of the filling due to a significant degree of destruction of the hard tissues of the crown.

The occurrence of secondary adentia is also caused by injuries to the teeth and jaws, chemical (acid) necrosis of the hard tissues of the dental crowns, surgical interventions for chronic inflammatory processes, benign and malignant neoplasms in the jaw bones. In accordance with the fundamental points of the diagnostic process, in these situations, partial secondary adentia recedes into the background in the clinical picture of the disease.

The pathogenetic basis of partial secondary adentia as an independent form of damage to the dentofacial system is due to large adaptive and compensatory mechanisms of the dentofacial system. The onset of the disease is associated with tooth extraction and the formation of a defect in the dentition and, as a consequence of the latter, a change in chewing function.

Rice. 97. Changes in the functional parts of the dental system during edentia.
a - functional centers; 6 - non-functional links.

The morphofunctionally uniform dental system disintegrates in the presence of non-functioning teeth (these teeth are devoid of antagonists) and groups of teeth whose functional activity is increased (Fig. 97). Subjectively, a person who has lost one, two or even three teeth may not notice a disturbance in chewing function. However, despite the absence of subjective symptoms of damage to the dental system, significant changes occur in it.

Increasing quantitative tooth loss over time leads to changes in chewing function. These changes depend on the topography of the defects and the quantitative loss of teeth: in areas of the dentition where there are no antagonists, a person cannot chew or bite off food; these functions are performed by preserved groups of antagonists. The transfer of the biting function to the group of canines or premolars due to the loss of the anterior teeth, and with the loss of chewing teeth, the chewing function to the group of premolars or even the anterior group of teeth disrupts the functions of periodontal tissues, the muscular system, and elements of the temporomandibular joints.

So, in the case shown in Fig. 97, biting food is possible in the area of ​​the canine and premolars on the right and left, and chewing in the area of ​​the premolars on the right and the second and third molars on the left.

If one of the groups of chewing teeth is missing, then the balancing side disappears; there is only a fixed functional center of chewing in the area of ​​the antagonizing group, i.e., loss of teeth leads to disruption of the biomechanics of the lower jaw and periodontium, disruption of the patterns of intermittent activity of functional centers of chewing.

With intact dentition, after biting off food, chewing occurs rhythmically, with a clear alternation of the working side in the right and left groups of chewing teeth. The alternation of the load phase with the rest phase (balancing side) determines the rhythmic connection to the functional load of periodontal tissues, characteristic contractile muscle activity and rhythmic functional loads on the joint.

When one of the groups of chewing teeth is lost, the act of chewing takes on the character of a reflex given in a certain group. From the moment of loss of part of the teeth, changes in the chewing function will determine the state of the entire dental system and its individual links.

I. F. Bogoyavlensky (1976) points out that changes that develop under the influence of function in tissues and organs, including bones, are nothing more than “functional restructuring.” It can occur within the limits of physiological reactions. Physiological functional restructuring is characterized by such reactions as adaptation, full compensation and compensation at the limit.

The work of I. S. Rubinov has proven that the effectiveness of chewing in various types of edentia is practically 80-100%. Adaptive-compensatory restructuring of the dental system, according to the analysis of masticograms, is characterized by some changes in the second phase of chewing, the search for the correct location of the food bolus, and a general lengthening of one complete chewing cycle. If normally, with intact dentition, it takes 13-14 s to chew an almond kernel (hazelnut) weighing 800 mg, then if the integrity of the dentition is damaged, the time is extended to 30-40 s, depending on the number of lost teeth and surviving pairs of antagonists. Based on the fundamental principles of the Pavlovian school of physiology, I. S. Rubinov, B. N. Bynin, A. I. Betelman and other domestic dentists proved that in response to changes in the nature of chewing food with partial edentia, the secretory function of the salivary glands and stomach changes , food evacuation and intestinal motility slow down. All this is nothing more than a general biological adaptive reaction within the physiological functional restructuring of the entire digestive system.

The pathogenetic mechanisms of intrasystemic restructuring in secondary partial edentia due to the state of metabolic processes in the jaw bones were studied in an experiment on dogs. It turned out that in the early stages after partial tooth extraction (3-6 months), in the absence of clinical and radiological changes, shifts occur in the metabolism of the bone tissue of the jaws. These changes are characterized by an increased intensity of calcium metabolism compared to the norm. Moreover, in the jaw bones in the area of ​​teeth without antagonists, the severity of these changes is higher than at the level of teeth with preserved antagonists. An increase in the incorporation of radioactive calcium into the jawbone in the area of ​​functioning teeth occurs at a level of practically unchanged total calcium content (Fig. 98). In the area of ​​teeth excluded from function, a significant decrease in the content of ash residue and total calcium is determined, reflecting the development of initial signs of osteoporosis. At the same time, the content of total proteins also changes. Characterized by a significant fluctuation in their level in the jawbone, both at the level of functioning and non-functioning teeth. These changes are characterized by a significant decrease in the content of total proteins in the 1st month of creating the experimental model of secondary partial adentia, then a sharp increase (2nd month) and a decrease again (3rd month).

Consequently, the response of the jaw bone tissue to the changed conditions of the functional load on the periodontium is manifested in changes in the intensity of mineralization and protein metabolism. This reflects the general biological pattern of the vital activity of bone tissue under the influence of unfavorable factors, when mineral salts disappear, and the organic base, devoid of a mineral component, remains for some time in the form of osteoid tissue.

Bone minerals are quite labile and, under certain conditions, can be “extracted” and again “deposited” under favorable, compensated conditions or conditions. The protein base is responsible for the ongoing metabolic processes in bone tissue and is an indicator of ongoing changes and regulates the processes of mineral deposition.

The established pattern of changes in the metabolism of calcium and total proteins in the early periods of observation reflects the reaction of the bone tissue of the jaws to new operating conditions. Here, compensatory capabilities and adaptive reactions are manifested with the inclusion of all protective mechanisms of bone tissue. During this initial period, when the functional dissociation in the dental system caused by secondary partial adentia is eliminated, reverse processes develop, reflecting the normalization of metabolism in the bone tissue of the jaws [Milikevich V. Yu., 1984].

The duration of the effect of unfavorable factors on the periodontium and jaw bones, such as increased functional load and complete exclusion from function, leads the dental system to a state of “compensation at the limit,” sub- and decompensation. The dentofacial system with impaired integrity of the dentition should be considered as a system with a risk factor.

Clinical picture

The complaints of patients are of a different nature. They depend on the topography of the defect, the number of missing teeth, the age and gender of the patients.

The peculiarity of the nosological form being studied is that it is never accompanied by a feeling of pain. In young people and often in adulthood, the absence of 1-2 teeth does not cause any complaints from patients. Pathology is detected mainly during clinical examinations and during routine sanitation of the oral cavity.

In the absence of incisors and canines, complaints about aesthetic defects, speech impairment, splashing of saliva when speaking, and the inability to bite off food predominate. If there are no chewing teeth, patients complain of a violation of the act of chewing (this complaint becomes dominant only if there is a significant absence of teeth). More often, patients note discomfort when chewing and the inability to chew food. There are frequent complaints about aesthetic defects in the absence of premolars in the upper jaw. It is necessary to establish the reason for tooth extraction, since the latter is important for the overall assessment of the condition of the dental system and prognosis. Be sure to find out whether orthopedic treatment was previously carried out and what designs of dentures were used. The need to determine the general state of health at the moment is undeniable, which can undoubtedly affect the tactics of medical manipulations.

On external examination, as a rule, there are no facial symptoms. The absence of incisors and canines in the upper jaw is manifested by the symptom of “recession” of the upper lip. With significant absence of teeth, a “recession” of the soft tissues of the cheeks and lips is noted. Partial absence of teeth on both jaws without preservation of antagonists is often accompanied by the development of angular cheilitis (jams); during the swallowing movement, the lower jaw makes a large amplitude of vertical movement.

When examining the tissues and organs of the mouth, it is necessary to carefully examine the type of defect, its extent (magnitude), the condition of the mucous membrane, the presence of antagonistic pairs of teeth and their condition (hard tissues and periodontal tissue), as well as the condition of teeth without antagonists, the position of the lower jaw in central occlusion and in a state of physiological rest. The examination must be supplemented by palpation, probing, determination of the stability of teeth, etc. An X-ray examination of the periodontium of teeth that will support various designs of dentures is mandatory.

The variety of options for secondary partial adentia, which have a significant impact on the choice of a particular treatment method, has been systematized by numerous authors.

The most widely used classification of dentition defects was developed by Kenedy, although it does not cover possible combinations in the clinic.

The author identifies four main classes. Class I is characterized by a bilateral defect not limited distally by the teeth, II - a unilateral defect not limited distally by the teeth; III - unilateral defect limited distally to the teeth; Class IV - absence of front teeth. All types of dentition defects without a distal limitation are also called end defects, while those with a distal limitation are called included. Each defect class has a number of subclasses. The general principle of identifying subclasses is the appearance of an additional defect within the preserved dentition. This significantly influences the course of clinical justification of tactics and the choice of one or another method of orthopedic treatment (type of denture).

Diagnosis

Diagnosis of secondary partial adentia is not difficult. The defect itself, its class and subclass, as well as the nature of the patient’s complaints indicate a nosological form. It is assumed that all additional laboratory research methods have not identified any other changes in the organs and tissues of the dental system.

Based on this, the diagnosis can be formulated as follows:

Secondary partial adentia on the upper jaw, IV class, first subclass according to Kenedy. Aesthetic and phonetic defect;
. secondary partial adentia on the lower jaw, class I, second subclass according to Kenedy. Chewing dysfunction.

In clinics where there are functional diagnostic rooms, it is advisable to establish the percentage of loss of chewing efficiency according to Rubinov.

During the diagnostic process, it is necessary to differentiate primary adentia from secondary.

Primary adentia due to the absence of tooth germs is characterized by underdevelopment of the alveolar process in this area and its flattening. Often primary adentia is combined with diastemas and tremata, an abnormality in the shape of the teeth. Primary adentia with retention is usually diagnosed after an X-ray examination. It is possible to make a diagnosis after palpation, but with subsequent radiography.

Secondary partial adentia, as an uncomplicated form, must be differentiated from concomitant diseases, such as periodontal disease (without visible pathological mobility of teeth and the absence of subjective discomfort), complicated by secondary adentia.

If secondary partial adentia is combined with pathological wear of the hard tissues of the crowns of the remaining teeth, it is fundamentally important to establish whether there is a decrease in the height of the lower part of the face in central occlusion. This significantly influences the treatment plan.

Diseases with pain syndrome in combination with secondary partial adentia, as a rule, become leading and are discussed in the relevant chapters.

The basis for the diagnosis of “secondary partial adentia” is the compensated state of the dentition after partial loss of teeth, which is determined by the absence of inflammation and degenerative processes in the periodontium of each tooth, the absence of pathological abrasion of hard tissues, deformation of the dentition (Popov-God ona phenomenon, tooth displacement due to periodontitis ). If the symptoms of these pathological processes are established, the diagnosis changes. Thus, in the presence of deformations of the dentition, a diagnosis is made: partial secondary adentia, complicated by the Popov-Godon phenomenon; Naturally, the treatment plan and medical tactics for managing patients are different.

Treatment

Treatment of secondary partial adentia is carried out with bridges, removable plate and clasp dentures.

A bridge-like fixed prosthesis is a medical device used to replace partial missing teeth and restore chewing function. It is strengthened on natural teeth and transmits chewing pressure to the periodontium, which is regulated by the periodontal muscle reflex.

It is generally accepted that treatment with fixed bridges can restore chewing efficiency to 85-100%. With the help of these prostheses, it is possible to fully eliminate phonetic, aesthetic and morphological disorders of the dental system. Almost complete compliance of the prosthesis design with the natural dentition creates the prerequisites for rapid adaptation of patients to them (from 2-3 to 7-10 days).

A removable plate prosthesis is a medical device used to replace partial missing teeth and restore chewing function. It is attached to natural teeth and transmits chewing pressure, regulated by the gingivomuscular reflex, to the mucous membrane and bone tissue of the jaws (Fig. 101).

Considering the fact that the basis of a removable laminar denture rests entirely on the mucous membrane, which, by its histological structure, is not adapted to perceive chewing pressure, chewing efficiency is restored by 60-80%. These dentures allow you to eliminate aesthetic and phonetic disorders in the dental system.

However, the methods of fixation and the significant area of ​​the base complicate the adaptation mechanism and lengthen its period (up to 1-2 months).

A clasp denture is a removable medical device for replacing partial missing teeth and restoring chewing function.

It is attached to natural teeth and relies on both natural teeth and the mucous membrane, chewing pressure is regulated in combination through periodontal and gingivomuscular reflexes.

The possibility of distributing and redistributing chewing pressure between the periodontium of supporting teeth and the mucous membrane of the prosthetic bed, combined with the possibility of avoiding tooth preparation, high hygiene and functional efficiency, has made these dentures one of the most common modern types of orthopedic treatment. Almost any defect in the dentition can be replaced with a clasp denture, with the only caveat that for certain types of defects the shape of the arch is changed.

In the process of biting and chewing food, chewing pressure forces of varying duration, magnitude and direction act on the teeth. Under the influence of these forces, responses occur in periodontal tissues and jaw bones.

Knowledge of these reactions and the influence of different types of dentures on them underlies the selection and justified use of one or another orthopedic device (denture) for the treatment of a particular patient.

Based on this basic position, the following clinical data have a significant influence on the choice of denture design and supporting teeth in the treatment of partial secondary adentia: class of dentition defect; length of the defect; condition (tone) of the masticatory muscles.

The final choice of treatment method may be influenced by the type of occlusion and some features associated with the profession of the patients.

Lesions of the dental system are very diverse, and no two patients have exactly the same defects. The main differences in the state of the dental systems of the two patients are the shape and size of the teeth, the type of bite, the topography of defects in the dentition, the nature of the functional relationships of the dentition in functionally oriented groups of teeth, the degree of compliance and the threshold of pain sensitivity of the mucous membrane of the toothless areas of the alveolar processes and the hard palate, the shape and sizes of toothless areas of the alveolar processes.

The general condition of the body must be taken into account when choosing the type of treatment device. Each patient has individual characteristics, and in this regard, two dentition defects that are externally identical in size and location require a different clinical approach.

Theoretical and clinical basis for choosing a treatment method with fixed bridges

The term “bridge” came to orthopedic dentistry from technology during the period of rapid development of mechanics and physics and reflects the engineering structure - the bridge. It is known in technology that the design of a bridge is determined based on the expected theoretical load, i.e., its purpose, span length, soil condition for supports, etc.

Almost the same problems face an orthopedic doctor with a significant adjustment to the biological object of influence of the bridge structure. Any design of a dental bridge includes two or more supports (medial and distal) and an intermediate part (body) in the form of artificial teeth (Fig. 102).

Rice. 102. Types of fixed dentures used to treat secondary adentia.

The fundamentally different static conditions of a bridge as an engineering structure and a fixed dental bridge are the following:

The bridge supports have a rigid, fixed base, while the supports of a fixed bridge are movable due to the elasticity of periodontal fibers, the vascular system and the presence of a periodontal gap;
. the supports and span of the bridge experience only vertical axial loads in relation to the supports, while the periodontium of teeth in a bridge-like fixed dental prosthesis experiences both vertical axial (axial) loads and loads at different angles to the axes of the supports due to the complex topography of the occlusal surface of the supports and the body of the bridge and the nature of the chewing movements of the lower jaw;

Rice. 103. Statics of a bridge as an engineering structure.

In the supports of the bridge and bridge-like prosthesis and the span, after the load is removed, the internal compressive and tensile stresses that have arisen subside (extinguish); the structure itself comes to a “calm” state;
. the supports of a fixed bridge prosthesis return to their original position after removing the load, and since the load develops not only during chewing movements, but also when swallowing saliva and establishing dentition in central occlusion, these loads should be considered as cyclic, intermittent-constant, causing a complex set of responses from the periodontium (see “Biomechanics of the periodontium”).

Thus, the statics of a bridge with two-sided, symmetrically located supports is considered as a beam lying freely on rigid “foundations”. With a force K applied to the beam in the center, the latter bends by a certain amount S. At the same time, the supports remain stable (Fig. 103).

A fixed bridge dental prosthesis with bilateral, symmetrically located supports should be considered as a beam rigidly clamped on an elastic base (Fig. 104).

The load K applied in the center of the intermediate part (body) of the bridge is evenly distributed between the supports.

K=P1+P2; P1P2

The force K, when applied to the body of the bridge, causes a moment of rotation (M), which is equal to the product of the magnitude of the force K and the length of the arm (a or b). Since when a force K is applied at the center of the body of the bridge, the shoulders a and bran, then the two moments of rotation - Ka and K" b, having opposite signs, are balanced.

If force K moves towards one of the supports (Fig. 105), then the moment of rotation and load in the area of ​​this support increase, and in the opposite one they decrease (arm a<б).

The load on the abutment tooth is always proportional to the distance of the support from the place where the force is applied.

Provided that the chewing pressure realized in the force K coincides with the functional (physiological) axis of one of the supporting teeth, then this tooth bears the full load, and in the second support the force K will be of the opposite sign.

The supports move under load - they sink deep into the dental alveoli (towards the bottom of the alveoli) until equal but oppositely directed forces arise from the periodontal fibers. A biostatic balance of forces is established - the applied force and elastic deformation of periodontal fibers and bone tissue. This connection can be determined statically by two counteracting moments of the “bridge-periodontal” system directed against each other. After removing the load, the supports return to their original position. As a result, they travel a distance equal to the values ​​of

Under the influence of a vertical load and an angle load during lateral movements of the lower jaw, a deflection S and a torque occur in the body of the bridge. As a result, the supports experience a tilting moment of< а. На внутренней стороне опор волокна периодонта сжимаются (+), на наружной — растягиваются (—), находясь в уравновешенном состоянии (см. рис. 105). Степень отклонения опор от исходного состояния (величина а) зависит от параметров тела мостовидного протеза, выраженности бугорков на окклюзионной поверхности, величины перекрытия тела мостовидного протеза в области передних зубов.

The basic principles of statics given in relation to a dental bridge dictate the need to systematize the types of dental bridges depending on the location of the supports, their number and the shape of the intermediate part.

Rice. 106. Types of bridge-like fixed dentures depending on the location and number of supports. Explanation in the text.

Thus, depending on the location of the supports and their number, it is necessary to distinguish 5 types of bridges: 1) a bridge with bilateral support (Fig. 106, a); 2) with intermediate additional support (Fig. 106, b); 3) with double (medial or distal) support (Fig. 106, c); 4) with paired double-sided supports (Fig. 106, d); 5) with a one-sided console (Fig. 106, d).

The shape of the dental arch is different in the anterior and lateral sections, which naturally affects the intermediate part of the bridge. Thus, when replacing anterior teeth, the intermediate part is arched; when replacing chewing teeth, it approaches a rectilinear shape (Fig. 107, a, b). When defects in the dentition in the anterior and lateral sections are combined and replaced with one bridge prosthesis, the intermediate part has a combined shape (Fig. 107, c, d).

The presence in the design of a bridge prosthesis of a cantilever element, an arched or straight body of a bridge prosthesis, different directions of the axes of the supporting teeth due to their anatomical location in the dentition significantly affect biostatics and should be taken into account when justifying treatment with bridge prostheses.

Rice. 107. Types of bridge-like fixed dentures depending on the shape of the intermediate part (body). Explanation in the text.

Rice. 108. Statics of the biomechanical system “bridge-like fixed denture - periodontium” with a cantilever element (indicated by an arrow). Explanation in the text.

In particular, when turning on a cantilever element, it is necessary to take into account the length of the lever opposing the lever of the applied force (see Fig. 106).

It is generally accepted that the longer the arm e (M1 = P1. e) compared to the arm c (M2 = K "c), the more it counteracts the eccentric load K on the console. In a state of equilibrium, the moment of rotation of the lever e acts against the moment of the lever c , i.e. Mi>M2 (Fig. 108). When the opposite lever is shortened, the fulcrum near the console is loaded under pressure, becomes a point of rotation, and the remote fulcrum experiences “stretching”, “dislocation” - a moment of rotation with a negative sign.

With an arched body of the bridge, the applied force K always acts in an eccentric vertical direction relative to the axes of the supports (canines, premolars). The larger the radius of the arc, the greater the negative effect of the torque on the supports (Fig. 109, a).

The moment of rotation is expressed as M = K-a, where a is a perpendicular segment to the transversal straight line connecting the supports to each other. Under the influence of force K, it becomes the axis of rotation, the moment of “overturning” the supports. To neutralize this negative component, Schroeder points out the need to include chewing teeth in the support of a bridge with an arcuate body to form counter-arms of the same length (Fig. 109, b), bilateral power blocks of the teeth. The rotational moment must be compensated by them.

Rice. 109. Statics of the biomechanical system “fixed bridge prosthesis - periodontium” with an arched shape of the prosthesis body. a - double-sided single support; b - double-sided multiple support.

With the rectilinear shape of the body of the bridge in the area of ​​the lateral teeth, vertical (centric or eccentric) chewing pressure is perceived by the complex relief of the chewing surface, where the slopes of the tubercles are inclined planes (Fig. PO). The force K, according to the wedge law, is decomposed into two components, of which the forces K( perpendicular to the axis and the resulting forces Kg cause a moment of rotation. The latter, not compensated by anything, leads to vestibular-oral deviations of the supporting teeth (Fig. 111).

In a state of biostatic equilibrium, the torques are equal to each other M1 = M2; their value does not exceed the value of elastic deformation of periodontal fibers. To maintain this balance, it is necessary to create the same type of slopes of the vestibular and lingual (palatal) tubercles when modeling the chewing surface. To compensate for the negative effect of the torque, one can consider connecting additional supports lying in a different plane, in particular canines or third molars.

The possibility of treatment with bridges and the application of additional chewing load is based on the general biological position about the presence of physiological reserves in human tissues and organs. This allowed V. Yu. Kurlyandsky to put forward the concept of “reserve forces of the periodontium.” It is confirmed in the analysis of an objective study of periodontal endurance to pressure - gnathodynamometry. The limit of periodontal endurance to pressure is the threshold load, an increase in which leads to pain, for example for premolars - 25-30 kg, molars - 40-60 kg. However, under natural conditions, when biting and chewing food, a person does not develop effort until pain occurs.

Consequently, part of the periodontal endurance to load is constantly realized in natural conditions, and part is a physiological reserve, realized under extreme conditions, in particular during illness.

It is accepted theoretically, approximately, to believe that out of 100% of the functional capabilities of an organ, 50% is normally consumed, and 50% constitutes a reserve. This is the main theoretical basis in the clinic for selecting and justifying the number of supporting teeth for a dental bridge and its structural elements, as well as fixation systems for removable denture structures.

The load on the periodontium of the supporting teeth, its magnitude and direction are directly dependent on the periodontal condition of the antagonist teeth. Under natural conditions, the size of the food bolus between the teeth does not exceed the length of three teeth. Therefore, we can assume that the maximum load, for example, in the area of ​​chewing teeth, is possible from the total endurance of the second premolar and two molars (7.75-50% of which is 3.9); in the area of ​​the front teeth - two central and two lateral incisors (4.5-2.25-50%).

Since the increase in chewing pressure will primarily determine the reaction of single-standing antagonist teeth, the contractile force of the masticatory muscles will be regulated precisely through the periodontal-muscular reflex of the latter. If the antagonist is a bridge, then the magnitude of the impact from it is the total value of the periodontal endurance of all supporting teeth. Let us consider specific clinical situations when deciding on the justified choice of a treatment method with bridges.

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