Methods for assessing chewing effectiveness. Determination of chewing efficiency. What type of fixation are attachments
Diagnosis- is a logical conclusion, a synthesis of the obtained subjective and objective research data. Diagnosis in orthopedic dentistry should reflect the size and topography of defects in hard tissues of teeth, dentition, condition oral mucosa, as well as concomitant diseases of the dentoalveolar system and complications.
For example: 1) dental hard tissue defect(mandatory what?), carious, non-carious or traumatic origin (non-carious diseases include: hypoplasia enamel, wedge-shaped defects, fluorosis, acid necrosis and pathological abrasion; trauma - acute and chronic), the degree of destruction of the crown part of the tooth must be indicated. 2) partial adentia(which jaw?) according to Kennedy: bilateral terminal (I class), one-sided terminal (P class), included in the region of the lateral teeth (III class), isolated included in the frontal region (1U class). Complications: traumatic occlusion, decreasing bite, secondary deformation(the phenomenon of Godon-Popov). .3) complete edentulous: the degree of atrophy according to I.M. Oksman, the compliance of the mucous membrane according to Supple.
Plan for preparing the oral cavity for prosthetics: sanitation of the oral cavity (removal of dental deposits, dental treatment, extraction of teeth or roots); special training ( depulping teeth, elimination of occlusal disorders, orthodontic preparation, alveolotomy, excision of scars, strands of the mucous membrane, deepening of the vestibule or floor of the mouth).
tab, veneer from what material and on what tooth;
pin construction (single-root, collapsible, how it was made, temporary, permanent) on the supporting tooth;
Single crown (from what material) on the supporting tooth;
Bridge prosthesis from what material, with supports on which teeth;
Partially removable lamellar denture for high, low, with which teeth (plastic, ceramic, porcelain), clasps for which teeth;
Clasp prosthesis(splinting clasp prosthesis) indicating the fixation system ( cast clasps, type of attachments, telescopic crowns) and on which teeth;
Other types of designs are possible with an indication of the type of materials, manufacturing method and supporting teeth.
A diary- displays the date of admission of patients, the amount of work performed and must be certified by the signature of the immediate supervisor.
Dispensary observation: if necessary, the date of the examination (year, month) of the subsequent visit is noted for the following diseases: pathological abrasion, periodontal tissue diseases, complete adentia, etc.
Epicrisis: the volume of orthopedic treatment is described (aesthetics, anatomical shape of the teeth, the integrity of the dentition, the height of the lower third of the face, the mobility of the teeth), it is indicated to what extent the chewing efficiency is restored (according to I.M, Oksman). recommendations are given for oral care and the use of prostheses.
Role-playing game"Maintaining an outpatient card of a dental patient"
FULL NAME. Ivanov V.P.
Year of birth. 1991.
Current complaints: violation chewing, aesthetics.
Disease history: A day ago, the crown of the central tooth of the upper jaw broke off when eating. The tooth was treated three years ago due to complications of caries.
General state: bad habits - smokes; concomitant diseases - no; hepatitis, tuberculosis, syphilis, HIV- denies; allergic anamnesis- unburdened anesthesia previously performed, effective, without pathologies.
Visual inspection: skin color - clear; the face is symmetrical; face type - conical; the height of the lower third of the face is not a change; the chin does not protrude; lips close - without tension; nasolabial and chin folds - moderately pronounced; mouth opening - free, painless; movements of the lower jaw - smooth, displacement during movement - no.
Study TMJ: the presence of a crunch, clicking, noise in the TMJ during the movement of the lower jaw is not recorded, chewing muscles are painless on palpation, submandibular lymph nodes palpation painless, not enlarged.
objective data
P | R | P | P | ||||||||||||
P | P | P | |||||||||||||
Inspection SOPR: the mucosa is pale pink, of moderate humidity, the gingival papillae are normal.
Examinations of teeth and dentition:
Intact teeth are without pathology, not mobile, percussion, probing are painless, the temperature reaction is negative, periodontal pockets are 0.1 mm.
- fillings are in a satisfactory condition, they correspond to the bite, the marginal diligence is dense.
Teeth are not mobile percussion sounding- painless, temperature reaction is negative. IROPZ 16; 25; 26; 36; 44; 45 - 0.5.
View bite: fixed, straight.
Condition of the dentition: the shape of the dentition is elliptical in the upper jaw, parabolic in the lower jaw. There are no secondary deformations.
Language: normal size, oval, frenulum - normal.
Additional examination methods:
From 07/05/2010. on the intraoral radiograph, in the periapical tissues of the 21st tooth without pathological changes, the canal was sealed up to the physiological apex, throughout.
Or according to I.M. Oksman
teeth | Total | ||||||||
V/H | 25% | ||||||||
LF | 25% |
Loss of chewing efficiency - 3% according to I.M. Oksman.
Diagnosis– defect hard tissues of the tooth as a result of caries, destruction of the crown 21 on 1/2 of the surface, IROPZ 16; 25; 26; 36; 44; 45 - 0.5; loss of chewing efficiency 3% according to I.M. Oksman.
Oral preparation plan prosthetics did not carry out.
Orthopedic treatment plan: stump pin design for 21 teeth; single metal-ceramic crown for 21 teeth.
A DIARY
date of | Amount of work performed | Manager's signature |
5.07.2010 | survey, documentation. Preparing the root of the 21st tooth for a stump pin structure, modeling the pin structure in the oral cavity with Lavax wax, applying a temporary filling - dentin paste. | |
6.07.2010 | checking and fitting of a metal stump pin structure on the root of the 21st tooth. Honey. treatment of the root and canal of the 21st tooth with 3% hydrogen peroxide and liquid for degreasing the canals, air; metal stump pin structure - 95% alcohol, air. Fixation of a metal stump pin structure in the root of the 21st tooth on Fuji. | |
7.07.2010 | under application anesthesia with the Ludoxor spray, the introduction of a retraction thread into the periodontal sulcus of the 21st tooth, the preparation of the 21st tooth for a metal-ceramic crown. Removal of a double impression from the upper jaw "Spidex", from the lower jaw - an alginate impression "Hydrogum soft | |
8.07.2010 | determination and fixation of central occlusion. | |
10.07.2010 | checking and fitting of a cast frame of a metal-ceramic crown for 21 teeth. Determining the color of ceramic cladding: Ivoclar - 4 A. | |
12.07.2010 | checking and fitting of a metal-ceramic crown for 21 teeth. Honey. treatment of the stump of the 21st tooth with 3% hydrogen peroxide, air; metal-ceramic crown - 95% alcohol, air. Fixation of a ceramic-metal crown for 21 teeth on Fuji. Advice and recommendations for the care of the oral cavity and prostheses are given. |
Dispensary observation: the patient does not need, recommended prophylactic oral examination once every six months.
Epicrisis: as a result orthopedic treatment defect hard tissues of the 21st tooth, the anatomical shape, aesthetics, integrity of the dentition of the upper jaw, chewing efficiency in full (100%) were restored.
Patient V.P. Ivanov, born in 1991, was given the necessary recommendations for caring for the oral cavity and a metal-ceramic crown on the 21st tooth.
Homework to clarify the topic.
Questions for self-preparation:
What is meant by medical documentation?
What is meant by medical history?
Procedure for maintaining an outpatient card?
Features of collecting complaints, anamnesis, studying the general somatic condition?
Features of the external examination?
Features of the examination of the oral cavity itself?
Features of the additional methods surveys?
Diagnosis, features of its setting?
Test tasks:
Initial test knowledge control
Option 1
1. The system, accounting and reporting documents intended for recording and analyzing data characterizing the health of individuals and populations, the volume, content and quality of medical care provided, as well as the activities of therapeutic and preventive institutions, are called:
1) orthopedic dentistry;
2) prevention;
3) medical statistics;
Medical documentation.
2. IN THE CLINIC OF ORTHOPEDIC DENTISTRY PATIENTS MAKE COMPLAINTS ABOUT:
1) the presence of a cavity in the tooth;
2) pain in the tooth under the crown;
3) pain in the tooth when taking sweets;
Night pain in the tooth.
3. WHEN Clarifying the GENERAL CONDITION OF THE ORGANISM, THE FOLLOWING IS NOTICED:
1) patient complaints;
2) with what the patient associates the development of the disease;
3) allergic anamnesis;
2. Oksman's method: the definition of chewing efficiency is based on the anatomical and physiological principle. A score is given for each tooth, including the wisdom tooth. This takes into account the area of the chewing or cutting surface, the number of tubercles, roots, features of the periodontium of the tooth and the place of the latter in the dentition. The lower and upper lateral incisors, as functionally weaker, are taken as a unit. THEM. Oksman recommends taking into account the functional value of the tooth in connection with periodontal disease. Therefore, with the mobility of the first degree, the teeth should be considered as normal, with the second degree, the percentage value is reduced by half, with the mobility of the third degree, they should be considered absent. Single-rooted teeth with severe symptoms of apical chronic or acute periodontitis are assessed as missing. Carious teeth to be filled are classified as full-fledged, and those with a destroyed crown are missing. Positive moments: the functional value of each tooth is taken into account not only in accordance with its anatomical and topographical data, but also with its functional capabilities.
Chewing coefficients of teeth according to I.M. Oksman
3. V.Yu. Courland proposed a static system for accounting for the state of the supporting state of the teeth, called by him parodontogram.
A periodontogram is obtained by entering a record of data about each tooth in a special drawing. Each tooth with a healthy periodontium was assigned a conditional coefficient based on Haber's gnathodynamometric data. The more pronounced the atrophy, the more the periodontal endurance decreases. Therefore, in the periodontogram, the decrease in periodontal endurance is directly proportional to the loss of the tooth socket. Accordingly, the coefficients of periodontal endurance to chewing pressure were established for various degrees of socket atrophy. The degree of socket atrophy is determined by radiological and clinical studies. Since atrophy is often uneven, the most pronounced changes are taken into account. The following degrees of socket atrophy are distinguished: degree 1 - atrophy by 1/4 of the socket length, degree II - by 1/2, degree III - by 3/4, degree IV - the tooth is to be removed.
Disadvantage of the method: Gaber's data take into account only the periodontal endurance to vertical load, the endurance coefficients have significant variability, the decrease in endurance is not directly proportional to the degree of socket atrophy, the ability of the periodontium to perceive masticatory pressure at different levels of the root is not the same.
Functional methods allow you to get the most correct idea of the violation of the function of chewing and its restoration after prosthetics.
Gelman in 1932, he took several grains of almonds weighing 5 g as a food irritant and, offering the patient to chew for 50 seconds, the residue was sifted through a series of sieves. The last sieve had round holes with a diameter of 2.4 mm. The remaining mass was carefully weighed. The proportion calculated the true loss of chewing. For example, 5 g - 100%; 2.5 g - X% (residue in the sieve).
Loss of chewing efficiency 50%. Therefore, the chewing efficiency is 50%.
Ru6in(1956) for the test, the patient is asked to chew a hazelnut weighing 800 mg until the swallowing reflex appears.
The methodology for determining the balance and calculating the percentage loss of chewing efficiency is the same as that of Gelman. When calculating, the weight of the residue and the chewing time should be taken into account. Studies have shown that with orthognathic bite and intact dentition, the nut kernel is completely chewed. in 14 seconds. As teeth are lost, chewing time lengthens; at the same time, the residue in the sieve increases.
4. Functional tests for diseases of the temporomandibular joint and bite pathology.
5. Study of masticatory pressure - gnathodynamometry.
6. Graphical methods for studying the chewing movements of the lower jaw (masticography).
7. Study of masticatory muscle function (myotonometry, electromyography, etc.).
8. General clinical tests (blood, urine, saliva, blood for sugar, etc.).
9. Allergological methods include:
1) allergic history;
2) skin allergy tests;
3) laboratory methods of specific allergy diagnostics.
10. Morphological, cytological, bacteriological and immunobiological research methods.
Preliminary and final diagnosis.
The diagnosis reflects the essence of the disease, and includes the following sections:
1) morphological changes (classification of defects in the dentition, jaws, type of mucous membrane, etc.);
2) functional part (chewing efficiency in %);
3) complications resulting from morphological changes (decrease in the height of the lower third of the face, deep incisal overlap, displacement of the midline, local form of pathological abrasion, seizures, gingivitis, etc.);
4) concomitant diseases, those that will affect the dental status: allergic background, endocrine pathology, diseases of the musculoskeletal system, etc.).
Treatment plan.
1. Preparation of the oral cavity for prosthetics:
General sanitation measures are mandatory for all patients: removal of dental deposits; removal of the roots of teeth, with the exception of those that can be used in further prosthetics; extraction of teeth that are not subject to treatment, which are foci of chronic sepsis; with mobility PI degrees - all teeth, P degree - on the upper jaw. Teeth on the lower jaw P the degree of mobility can be left;
Special therapeutic - depulpation of teeth, replacement of metal fillings;
Surgical - removal of exostoses, resection of the hypertrophied alveolar process, elimination of the palatine torus, elimination of cicatricial strands of the mucosa, plastic frenulum, deepening of the vestibule of the oral cavity, resection of the apex of the tooth root, removal of significantly protruding teeth, implantology, etc.;
Orthopedic elimination of secondary deformations of the occlusal surface by grinding, restructuring of the myotatic reflex, etc.;
Orthodontic preparation of the oral cavity - elimination of secondary deformities with the help of special devices.
2. Type of prosthetics:
The formula of the orthopedic design;
Therapeutic activities.
Diary of orthopedic treatment.
All visits to the patient are recorded with the date and a detailed description of the clinical procedures during repeated visits after the application of the prosthesis, complaints are described, objective examination data, the nature of the assistance provided and the patient's habituation to the prosthesis, an assessment is given of the immediate results of prosthetics.
Epicrisis and prognosis of orthopedic treatment.
1. The full name, age, complaints of the patient on the day of contacting the clinic are indicated. preliminary diagnosis. Start and end of treatment. Prosthesis design. The patient's condition as a result of treatment is described and the prognosis is indicated.
The term of the control examination of the patient (in 30 - 40 days) in order to check the long-term results of treatment.
2. An outpatient card is a mandatory legal and medical document, which contains the examination data, diagnosis, orthopedic treatment plan and recommendations, and their implementation. All data must be recorded consistently and in full. The outpatient card is a legal document and plays an important role in resolving various conflict situations and in investigative practice.
3. Deontology (from the Greek deon, deontos - duty, due, logos - teaching) is the science of the professional duty of medical workers. Closely related to medical deontology is medical ethics, which studies the moral aspects of medicine. The success of treatment largely depends on the psychological state and mood of the patient. The clinical actions of the doctor must comply with the medical commandment: "Do no harm." Mental upheavals are remembered by patients much more than the unprofessionalism of a doctor. Negative impressions about the doctor and about medicine in general remain with the patient for many years, and sometimes it is very difficult to fight these prejudices. Positive results of treatment are largely determined by the favorable attitude of the patient to the doctor, his confidence in the correctness of the chosen treatment. There are generally accepted norms of behavior for a medical worker in a clinic:
1) polite and respectful attitude towards colleagues and patients. Maximum attention, kindness, patience and caution when talking with patients;
2) save medical secrecy;
3) certain requirements for appearance: clean, ironed white coat, change of shoes;
4) modesty in makeup, hair, moderate use of perfumes, jewelry;
5) compliance with certain sanitary and hygienic standards (changing a glass in the presence of the patient, washing hands after the patient is seated in a chair).
When receiving a patient, in his presence, all conversations on extraneous topics with colleagues and staff are prohibited. When talking with the patient, you should win him over, inspire him with confidence in success and eliminate the feeling of anxiety and fear. You need to talk with the patient confidently, but delicately, directing the conversation in the right direction and focusing on issues of interest. It is necessary to take into account the personality characteristics of each patient, the type of higher nervous activity and individual behavioral reactions. A good doctor is always a good psychoanalyst and actor. It is desirable that the patient starts and ends treatment with the same doctor, the replacement of the doctor is carried out only when necessary (illness, dismissal).
The patient must feel comfortable. Soundproofing of the waiting room is required.
In the course of the activities of medical workers, medical errors may occur that arise as a result of delusion and are most often the result of insufficient medical experience or are due to an atypical course of the disease. It is necessary to distinguish from them medical offenses that are associated with improper (most often negligent, negligent) performance of duties, failure to provide assistance to a patient without a good reason, receipt of illegal remuneration, violation of the storage and accounting of potent, poisonous and narcotic drugs, disclosure of medical secrets that led to the moral and physical suffering of the patient.
In the article, we will consider what chewing efficiency is according to Agapov.
This concept reflects the most important indicators of the condition of the teeth and jaw structure. This is the strength of the muscle endings of the lower jaw, carrying out chewing movements. It is necessary for crushing, biting and crushing food. This indicator is measured in separate parts of the dentoalveolar system. There is also such a thing as gnathodynamometry, which is the muscle fibers of the chewing apparatus, as well as the resistance of dental tissues to jaw compression. This method is implemented using a special device called a gnatodynamometer.
Anatomical features of the teeth
Most dentists who work with this topic take the chewing power of the weakest tooth as a unit. And the pressure of the remaining teeth is determined in comparison with it. Then, when calculating the constant of such pressure, doctors are guided by such anatomical features of the teeth:
- surface size;
- the number of roots;
- the presence of bumps;
- distance from the angle of the lower jaw;
- periodontal features
- transverse sections of the neck.
Consider chewing efficiency according to Agapov in more detail.
Methods of determination
Voltage measurement according to Agapov is carried out using an electronic gnatodynamometer Perzashkevich and Rubinov. It includes specialized sensors that are built into the measuring head of a special removable nozzle.
A brass plate is located in the sensor, which is attached to the microammeter. The person sits in a chair. It is very important that he is comfortable and psychologically comfortable. Between the jaws, the specialist inserts a nozzle into the mouth and the patient squeezes it with his teeth until pain. Thus, chewing pressure is displayed on the scale of the device at this moment. The sensor values are fixed. Gnathodinamometric indicators can depend on many factors:
- the gender of the person;
- individual characteristics;
- existing diseases (periodontal disease, periodontitis and others);
- partial loss of teeth;
- age.
Averages
The values of chewing efficiency according to Agapov are shown on the device in kilograms. Averages vary between 15-36 for the front teeth and 45-78 kg for the molars. They have importance to optimize the processes of prosthetics, since they determine the sensitivity of the periodontium to the load, help to establish the design of a particular prosthesis.
The average values of masticatory pressure were established, which were taken as the basis for observations and the correspondence of the periodontal force load: in women on the incisors - 20-32 kg; in women on molars - 40-62 kg; in men on the incisors - 25-45 kg; in men on molars - 50-75 kg.
Pressure on the teeth in kilograms
According to the works of N. I. Agapov, there are tables with the distribution of chewing force for each tooth, however, it should be borne in mind that they are all approximate. The endurance of periodontal tissues as a whole (936 kg in women and 1408 kg in men) is almost never realized, since the maximum power of contractions of the masticatory apparatus is 390 kg. Gnatometry is very rarely used in modern dentistry due to the following disadvantages:
- only the vertical pressure is determined, but the horizontal force is not taken into account;
- the result cannot be absolutely accurate;
- rapid deformation of the spring;
- the result is influenced by the psychosomatic state of the patient, which can change during the day.
Calculation principles
N. I. Agapov’s method is based on the calculation of the chewing force of each tooth in percentage to the entire jaw apparatus. As a rule, a total count of the number of teeth is used to determine violations. N. I. Agapov considers this to be fundamentally wrong, since their effective and power values differ significantly. He developed a special table in which the coefficients are distributed between each tooth.
N. I. Agapov took the chewing efficiency of the entire chewing apparatus as 100% and calculated the chewing pressure of each tooth as a percentage, obtaining the chewing efficiency by adding the chewing coefficients of the remaining teeth.
The main amendment of this author is his conclusion that teeth are most effective only in pairs, and those that have lost antagonists practically lose their main functions. This means that if one tooth is missing, then two are missing at once. And the calculation of chewing efficiency, respectively, must be carried out according to the number of paired teeth. When applying this amendment, the indicators are completely different.
Without correction, chewing efficiency is 50%, meanwhile, when using N.I. Agapov's amendment, chewing efficiency is 0. In the event that the patient does not have a single pair of antagonizing teeth.
What else is taken into account in the assessment of chewing efficiency according to Agapov?
Oksman's amendments
Oksman I. M. pointed out the need and importance of taking into account the activity of existing teeth, taking into account their mobility. At the first stage of pathological mobility, chewing efficiency corresponds to 100%. At the second stage - 50%, at the third - its complete absence is stated. The last degree also includes teeth that are affected by periodontitis. Oksman, studying the developments of Agapov, recorded antagonist teeth in the form of a fraction. Indicators that indicate the loss of chewing efficiency are recorded in the following order: in the numerator - the maxillary value, in the denominator - the mandibular value. According to this scheme, it is most convenient for a specialist to imagine the state of the masticatory apparatus. Gnatodynamometric values are important in dental prosthetics and orthodontics. They may be influenced by:
- the psychological state of the patient;
- measurement reactivity;
- compensatory ability of periodontal receptors and numerous other factors.
With the help of gnatometry, the following is carried out: tracking the dynamics of therapeutic procedures and the functionality of implants, measuring the pressure between pairs of teeth, determining the functionality of prostheses.
Static systems in the form of tables
To calculate the endurance of the periodontium and the strength of each tooth in the process of chewing, certain tables have been proposed, which are called static systems for determining chewing efficiency. In these tables, the role of each tooth in the chewing process is determined by a constant value, which is expressed as a percentage that determines the interpretation of the result.
When compiling such tables, the importance of each tooth is determined by the index of the cutting and chewing surface, the size of the surface, the number of roots, as well as the distance at which they are located from the angle of the jaw. Several tables were proposed, which were developed according to a single principle (Wustrow, Duchange, Mamlock, etc.). In domestic practice, the static system for calculating chewing efficiency according to Agapov has become widespread.
Chewing coefficients - transcript
N. I. Agapov took the efficiency of the dental apparatus as 100%, and for the constant of endurance and chewing ability of the periodontium - a small incisor, comparing all the teeth with it. Thus, in his table, each tooth has a constant coefficient.
Subsequently, N. I. Agapov made an amendment to this table, recommending that when calculating the chewing efficiency of the dentition, take into account the presence of antagonist teeth.
In determining chewing efficiency according to Agapov, the value of each of the teeth is constant and in no way depends on the state of the periodontium. For example, the role of the canine in chewing is always determined by the same coefficient, which does not depend on whether it has pathological mobility. This is considered a serious flaw in the system being analyzed. However, there have been attempts to compile new systems in which the strength of the periodontal pressure during chewing depended on the degree of its defeat. In this case, the assessment is given to each tooth, including the wisdom tooth. At the same time, the surface area, the number of roots and tubercles, the characteristics of the periodontium and its place in the dental arch are taken into account. The lateral incisors, as functionally weak, were taken as a unit. Central incisors and canines - for two units, first molars for six, premolars for three. As a result of such calculations, a new table was compiled.
Loss of chewing efficiency according to Agapov
The indicators are used when passing the draft medical commission. This method is not used to establish the passability category. military service. Young people who have:
- 10 or more teeth are missing on one jaw, or they are replaced by a removable denture;
- 8 molars are missing on one jaw;
- missing 4 molars on both jaws with different sides, or they are replaced by their removable dentures.
One of the indicators of the state of the dental system is chewing efficiency. Some clinicians, in particular S. E. Gelman, use the term chewing power instead. But power in mechanics is the work done per unit of time, it is measured in kilograms. The work of the chewing apparatus can be measured not in absolute units, but in relative ones, that is, by the degree of food grinding in the oral cavity as a percentage. Therefore, it is more correct to use the concept of chewing efficiency. Thus, chewing efficiency should be understood as the degree of grinding of a certain amount of food in a certain time.
Methods for determining chewing efficiency can be divided into static, dynamic (functional) and graphic.
Static Methodsare used for direct examination of the oral cavity of the subject, while assessing the condition of each tooth and all existing teeth and entering the data obtained in a special table in which the share of each tooth in the chewing function is expressed by the corresponding coefficient. Such tables have been proposed by many authors, but in our country the methods of N. I. Agapov and I. M. Oksman are more often used.
In the table of I. I. Agapov, the lateral incisor of the upper jaw is taken as a unit of functional power (Table 3).
In total, the functional value of the dentition is 100 units. The loss of one tooth in one jaw is equated (due to a violation
functions of its antagonist) to the loss of two teeth of the same name. In the table of N.I. Agapov, wisdom teeth and the functional state of the remaining teeth are not taken into account.
I. M. Oksman proposed a table for determining the chewing ability of teeth, in which the coefficients are based on taking into account anatomical and physiological data: the area of the occlusal surfaces of the teeth, the number of tubercles, the number of roots and their sizes,
the degree of atrophy of the alveoli and the endurance of teeth to vertical pressure, the condition of the periodontium and the reserve forces of non-functioning teeth. In this table, the lateral incisors are also taken as a unit of chewing power, the wisdom teeth of the upper jaw (three-cusp) are estimated as 3 units, the lower wisdom teeth (four-cusp) - as 4 units. The total is 100 units. The loss of one tooth entails the loss of the function of its antagonist. In the absence of wisdom teeth,
take 28 teeth for 100 units.
Taking into account the functional efficiency of the masticatory apparatus, an amendment should be made depending on the condition of the remaining teeth. In periodontal diseases and tooth mobility of I or II degree, their functional value is reduced by one quarter or half. With tooth mobility of the III degree, its value is equal to
zero. In patients with acute or exacerbated chronic periodontitis, the functional value of the teeth is reduced by half or equal to zero.
In addition, it is important to take into account the reserve forces of the dento-jaw system. To take into account the reserve forces of non-functioning teeth, the percentage of loss of chewing ability in each jaw should be additionally noted as a fractional number: in the numerator for the teeth of the upper jaw, in the denominator for the teeth of the lower jaw. The following two dental formulas are an example:
80004321 1230007880004321 12300028
87654321 1234567800004321 12300078
In the first formula, the loss of chewing ability is 52%, but there are reserve forces in the form of non-functioning teeth of the lower jaw, which are expressed by designating the loss of chewing ability for each jaw as 26/0%.
With the second formula, the loss of chewing ability is 59% and there are no reserve forces in the form of non-functioning teeth. Loss of chewing ability
each jaw separately can be expressed as 26/30%.
The prognosis for the restoration of function in the second formula is less favorable.
To bring the static method closer to clinical diagnosis, V.K. Kurlyandsky proposed an even more detailed scheme for assessing chewing efficiency, which was called an odontoperiodontogram.
Periodontogramis a drawing scheme in which data is entered about each tooth and its supporting apparatus. The data are presented in the form symbols obtained as a result of clinical examinations, X-ray studies and gnatodynamometry. These include the following designations: . N - without pathological changes; 0(ft 4 the tooth is missing; 1/4 - atrophy of the first degree; 1/2 — atrophy of the second degree; 3/4 - atrophy of the third degree. Atrophy more than 3/4 is referred to the fourth degree, in which the tooth is held by soft tissues and must be removed.
The endurance of periodontal supporting tissues is designated by conditional coefficients, compiled on the basis of proportional ratios of tooth endurance to pressure in people who do not have periodontal disease. The latter is determined by gnatodynamometry of individual groups of teeth.
Depending on the degree of atrophy and the degree of tooth mobility, the coefficient of endurance of the supporting tissues to the loads that occur during food processing decreases accordingly.
Each tooth has reserve forces not used up in crushing food. These forces are approximately equal to half of the possible load that the periodontium can normally bear.
These forces vary depending on the degree of damage to the periodontal supporting tissues.
Normally, the endurance coefficient of the sixth tooth is 3, and its reserve strength is 1.5 units. With an increase in the degree of atrophy, the reserve force decreases. So, with atrophy of the holes of the first degree, the reserve forces of the sixth tooth are 0.75 units, with the second degree - 0, and with the third degree, functional failure sets in.
The scheme-drawing of the future odontoparodontogram consists of three rows of cells arranged parallel to each other.
In the middle of the drawing there is a row of cells with the designation of the dental formula, and above and below this row there are cells into which data on the condition of the teeth and periodontal bone tissue (normal, degree of atrophy, absence of teeth) are entered. Then comes a series of cells in which the data of the residual strength of the supporting tissues are set, expressed in conditional coefficients.
After filling in the scheme-drawing with conventional symbols, the coefficients of the upper and lower jaws are added, and the resulting scheme is placed on the right half of the odontoparodoitogram. Based on the summary data, the power relationships between the dentition of the jaws are determined.
In the given odontoperiodontogram, the force ratio between the jaws is 25.2: 21.7, which indicates the force prevalence of the dentition of the upper jaw over the dentition of the lower jaw.
The data of the power ratios of individual groups of teeth of the frontal and chewing jaws of both jaws are recorded against each group of teeth above and below the scheme of the odontoperiodontogram. These data make it possible to establish the power prevalence of the same-named groups of teeth and the localization of traumatic nodes.
In the given odonto-periodontogram, the force ratio between the anterior teeth is 6.6 to 4.6, which indicates the force prevalence of the anterior teeth of the upper jaw over the teeth of the lower jaw. Due to the mismatch of power relationships, a traumatic knot and pain occur during biting off food. The same picture is observed in the region of the group chewing teeth. It is most pronounced in the region of the chewing teeth on the right side of the jaw, where the ratio of forces is 9.3 and 6.8. Such force prevalence between the teeth also leads to the development of traumatic knots. When determining the power ratios between the teeth, it should be remembered that they can change due to the compensatory adaptations of the patient during food processing. The latter depends on the condition and location of the teeth in the jaw. So, in the absence of chewing teeth, the patient is forced to chew food with the frontal teeth, and in case of pain in the area of the frontal teeth, bite off the food with the premolars, if they are present in the jaw. Depending on this, the power ratios can change in a favorable or unfavorable direction for the affected periodontal tissues.
The data of the odonto-periodontogram indicate the need to equalize the power relationships between individual groups of teeth and the dentition as a whole through orthopedic interventions. In addition, the odontoperiodontogram makes it possible to: 1) determine the length of the splinting device; 2) set the number of supporting teeth for the bridge and Clasps for the removable denture.
Among the static schemes described above, the odontoperiodontogram is the least static, although it is not devoid of the disadvantages inherent in all schemes, which consist in the use of once established and arbitrarily rounded coefficients to assess the dynamic processes that determine the endurance of the periodontium to chewing pressure at various functional state-yah. Perhaps that is why the described methods are called static, although they arose on the basis of gnatodynamometric, i.e., in their essence, functional studies.
The static methods described above for determining the effectiveness of chewing, or, more precisely, the resistance of the periodontium to pressure during chewing, make it possible to judge the functional state of the chewing apparatus based on a simple arithmetic addition of the results of the obtained studies of each individual tooth (gnatodynamometry), radiological or clinical. However, the indices derived in this way characterize the functionality of the masticatory system too remotely. In some cases, the chewing function can be sharply disturbed with the loss of several teeth and, on the contrary, remains within the normal range in the absence of a more significant number of teeth. Consequently, a high degree of adaptability of the chewing system, the complexity of the interaction of its individual elements, as well as the effective function, which consists in the mechanical and chemical processing of food - all these processes are practically inaccessible to the static method.
For a more accurate determination of the functional state of the dentoalveolar system, functional diagnostic methods are used. These include chewing tests, masticography, myography, myotonometry, electromyography, myotonodynamometry, electromyomasticography.
Functional methods for determining chewing efficiency.The effectiveness of the chewing function depends on a number of factors: the presence of teeth and the number of their articulating pairs, teeth affected by caries and its complications, the condition of the periodontium and chewing muscles, the general condition of the body, neuroreflex connections, salivation and the qualitative composition of saliva , as well as the size and consistency of the food bolus. With pathological phenomena in the oral cavity (caries and its complications, periodontitis and periodontal disease, defects in the dentition, dentition and jaw anomalies), morphological disorders are usually associated with functional insufficiency.
Chewing samples. Christiansen in 1923, for the first time, he developed their methodology. The subject is given three identical cylinders of coconut for chewing. After 50 chewing movements, the subject spits out the chewed nuts into the tray; they are washed, dried at a temperature of 100 ° for 1 hour and sieved through 3 sieves with holes of different sizes. By the number of unsifted particles remaining in the sieve, the effectiveness of chewing is judged.
The Christiansen chewing test technique was further modified in our country C; E. Gelman in 1932
Gelman's chewing test.S. E. Gelman proposed to determine the effectiveness of chewing not by the number of chewing movements, as Christiansen , and for a period of time 50 sec. To obtain a chewing test, a calm environment is required. It is necessary to prepare packaged almonds, a cup (tray), a glass of boiled water, a glass funnel with a diameter 15 X 15 cm, gauze napkins size 20 X 20 cm, a water bath or a pan, a metal sieve with holes of 2.4 mm, balance with a weight.
The subject is given 5 g of almond kernels for chewing, and after the indication “start”, 50 seconds are counted. Then the subject spits the chewed almonds into the prepared cup, rinses his mouth with boiled water (if there is a removable denture, rinses it too) and also spits it into the cup. In the same cup, add 8-10 drops of a 5% sublimate solution, after which the contents of the cup are filtered through gauze over a funnel. The almonds remaining on the gauze are placed in a water bath to dry; while taking care not to overdry the sample, as it may lose weight. A sample is considered dried when its particles do not stick together during kneading, but separate. Particles of almonds are carefully removed from a gauze napkin and sifted through a sieve. With intact dentition, the entire chewing mass is sieved through a sieve, which indicates 100% chewing efficiency. If there is a residue in the sieve, it is weighed and, using the proportion, the percentage of violation of the chewing efficiency is determined, i.e. the ratio of the residue to the entire mass of the chewing sample. So, for example, if 1.2 g is left in the sieve, then the percentage loss of chewing efficiency will be equal to
5: 100 - 1.2; x;
X \u003d (100 X 1.2) / 5 \u003d 24%
Physiological chewing test according to Rubinov.According to I. S. Rubinov, the samples obtained by chewing 5 g of almonds are inaccurate, since such an amount of food substance makes the act of chewing difficult. He considers it more physiological to limit one grain of hazelnut weighing 800 mg for a chewing test. The period of chewing is determined by the appearance of the swallowing reflex and is equal to an average of 14 seconds. When a swallowing reflex occurs, the mass is spit into a cup; its further processing corresponds to the Gelman method. In cases of difficulty in chewing the nut kernel, I. S. Rubinov recommends using cracker for the sample; the time of chewing a cracker until the swallowing reflex appears is on average 8 s. At the same time, it should be pointed out that chewing a cracker causes a complex of motor and secretory reflexes that contribute to better absorption of the food bolus.
With various disorders in the oral cavity (carious destruction of teeth, their mobility, defects in the dentition, malocclusion, etc.), the chewing period is lengthened. Samples can also establish the effectiveness of prosthetics, depending on the design of prostheses and their quality.
L. M. Demner suggests weighing the entire chewed mass, both remaining in the sieve after sifting it, and passing through the sieve in order to identify the number of food particles remaining in the oral cavity or quietly swallowed during the chewing test.
However, there are shortcomings in conducting these tests. In the Christiansen method, the test is done after 50 chewing movements. This figure, no doubt, is arbitrary, because one person, depending on his chewing stereotype, needs 50 chewing movements to grind food, and for another, for example, it is enough ZO. S. E. Gelman tried to regulate the sample in time, but did not take into account the fact that different individuals grind food to varying degrees, that is, some people swallow more chopped food, others less, and this is their individual the norm.
According to the method of I. S. Rubinov, chewing efficiency is judged by the time of chewing 0.8 g of hazelnut until the swallowing reflex appears. This technique is devoid of the above disadvantages, however, it makes it possible to judge the restoration of efficiency only with perfect adaptation to prostheses.
Determining the place of static and functional methods for studying the effectiveness of chewing in the clinic of orthopedic dentistry, it must be emphasized that it would be a mistake to oppose them on the grounds that the former are called static, and the latter are functional, as well as to replace some methods others. Indeed, the static methods are based on gnathodynamometric methods, i.e. functional studies, which, as mentioned above, are not flawless in functional terms.
Graphic methods for recording the movements of the lower jaw and the functional state of the muscles.Graphic registration of movements of the lower jaw, on the basis of which articulators were built - the first mechanical models of the musculoskeletal apparatus of the masticatory system, played a positive role. The design of dentures adapted to the simplest movements of the lower jaw, which immeasurably improved the quality of prosthetics, at the same time opened up new perspectives for the theory and practice of orthopedic dentistry. The solution of these problems required the involvement of modern functional research methods in the clinic of orthopedic dentistry.
The most fundamental studies of the bio-mechanics of the masticatory system have been carried out using mastication and electromyography.
Mastication. The chewing stereotype depends on many conditions: the nature of articulation, occlusion, the length and topography of dentition defects, the presence or absence of a fixed occlusion height (interalveolar height) and, finally, on the constitutional and psychological characteristics of the patient. Masticography, which allows you to graphically record the dynamics of chewing and non-chewing movements of the lower jaw, is a method for objectively studying this stereotype. The first attempt to record the movements of the lower jaw using a kymog-raf was made by N. I. Krasnogorsky (1906). Then this technique has undergone many modifications and at present it looks relatively simple. In 1954, I. S. Rubinov proposed a device - a masticatiograph and developed a method for registering movements of the lower jaw during chewing on a kymograph, which he called masticationography.
Mastication is a graphical method for recording reflex movements of the lower jaw (from the Greek. masticatio - chewing, grapho - writing). To use this method, apparatuses were constructed, consisting of recording devices, sensors and recording parts. The recording was made on a kymograph or on oscillographic and strain gauge installations.
The most appropriate place for the installation of recording devices should be considered the submental region of the lower jaw, where the soft tissues are relatively little displaced during the function. In addition, the amplitude of movements of this part of the lower jaw during chewing is greater than its other parts, as a result of which the recording device captures them better. Experience with devices that have several recording
devices, showed that they are suitable for detailed studies only in a special laboratory. In this regard, a simpler and more convenient apparatus was designed - a masticatsiograph, which allows recording the movements of the lower jaw on a kymograph under normal physiological conditions.
The device consists of a rubber balloon (B) placed in a special plastic case (A), which is attached to the chin region of the lower jaw with a bandage (C) with a graduated scale (E)> showing the degree of pressing the balloon to the chin. The balloon is connected by means of an air transmission (T) to the Marey capsule (M), which makes it possible to record the movements of the lower jaw on the kymog-raf (K).
The use of the described technique showed that the recording of the chewing movements of the lower jaw is a series of wave-like curves following one after another. The whole complex of movements associated with chewing a piece of food, from the beginning of its introduction into the mouth until the moment of swallowing, is characterized as the chewing period (Fig. 87). In each chewing period, five phases are distinguished. On a kilogram, each phase has its own characteristic record.
First phase- state of rest - corresponds to the period before the introduction of food into the mouth, when the lower jaw is motionless, the muscles are in minimal tone and the lower dentition is 2-3 mm away from the upper, that is, it corresponds to the resting position of the lower jaw. On the kymogram, this phase is indicated as a straight line at the beginning of the chewing period, that is, an isoline.
Second phase- opening the mouth and introducing food. Graphically, it corresponds to the first ascending knee of the curve, which starts immediately from the line of rest. The scope of this knee depends on the degree of opening of the mouth, and its steepness indicates the speed of insertion into the mouth.
Third phase- the initial phase of the chewing function (adaptation), starts from the top of the ascending knee and corresponds to the process of adaptation to the initial crushing of a piece of food. Depending on the physical and mechanical properties of food, changes occur in the rhythm and scope of the curve of this phase. During the initial crushing of a whole piece of food in one movement, the curve of this phase has a flat top (plateau), turning into a gentle downward knee - to the level of rest. At the initial compression of a piece of food due to several movements, by looking for best place and position, for its refinement, there are corresponding changes in the nature of the curve. Against the background of a flat top, there are a number of short undulating rises located above the level of the line of rest. The presence of a flat top in this phase indicates that the force developed by the chewing muscles did not exceed the resistance of the food and did not crush it. As soon as the resistance is overcome, the plateau turns into a descending knee. The initial phase of the chewing function, depending on various factors, can be displayed graphically in the form of a single wave or is a combination of waves made up of several ascents and descents of different heights.
Fourth phase- the main phase of the chewing function - is graphically characterized by the correct periodic alternation of chewing waves. The masticatory wave includes all movements that are associated with one lowering and raising of the lower jaw until the teeth close. It is necessary to distinguish between the ascending knee, or the rise of the AB curve, and the descending knee, or the descent of the BS curve. The ascending knee corresponds to a complex of movements associated with lowering the lower jaw. The descending knee corresponds to a set of movements associated with raising the lower jaw. The top of the masticatory wave B indicates the limit of the maximum lowering of the lower jaw, and the value of the angle indicates the speed of transition to the lifting of the lower jaw.
The nature and duration of these waves in the normal state of the dentition and jaw system depend on the consistency and size of the piece of food. When chewing soft food, frequent uniform rises and descents of masticatory waves are noted. When chewing solid food in the initial phase of the chewing function, there are more rare descents of masticatory waves with a more pronounced increase in the duration of the wave-like movement.
Then successive ascents and descents of chewing waves become more frequent.
The lower loops between the individual waves (0) correspond to pauses when the lower jaw stops during the closing of the teeth. The size of these loops indicates the duration of the closed state of the dentition. The presence of contacts between the dentition can be judged by the level of location of the lines of intervals or closure loops. The location of the closure loops above the level of the line of rest indicates the absence of contact between the dentition. When the chewing surfaces of the teeth are in contact or close to it, the closure loops are located below the line of rest.
The width of the loop formed by the descending knee of one chewing wave and the ascending knee of the other registers the speed of the transition from closing to opening of the dentition. According to the sharp corner of the loop, it can be judged that the food was subjected to short-term compression. The larger the angle, the longer the compression of food between the teeth. The straight platform of this loop means the stop of the lower jaw during the crushing of food. A loop with a wave-like rise in the middle indicates rubbing of food during sliding movements of the lower jaw.
After the end of the main phase of chewing, the phase of the formation of a lump of food begins, followed by swallowing it. Graphically, this phase looks like a wavy curve with some decrease in the height of the waves. The act of forming a lump and preparing it for swallowing depends on the properties of the food: the formation of a lump of soft food occurs in one step, the formation of a lump of hard, crumbly food takes place in several steps. Corresponding to these movements, curves are recorded on the kymograph tape.
After swallowing the food bolus, the state of rest of the masticatory muscles is again established. Graphically, it is displayed as a horizontal line. This state is the first phase of the next chewing period.
Attention should be paid to the fact that with the help of one balloon it is possible to record lateral shifts of the lower jaw. With lateral shifts, the lower jaw moves in a horizontal plane with simultaneous lowering. This is due to the fact that most people have overlapping upper front teeth. lower teeth and a certain slope of the articular tubercles. With a lateral shift of the lower jaw and its lowering, the balloon of the masticatiograph is compressed, which causes a corresponding rise in the membrane of the Marey capsule through air transmission. The return of the lower jaw from the lateral shift to the central closure is associated with its rise and causes the feather of the Marey capsule to descend. Thus, lateral displacements of the mandible ti in the area of the closure loops on the masticogram are displayed by the corresponding wave.
As mentioned above, fixation to the chin of a plastic case with a rubber balloon is carried out using a bandage with a graduated scale or a wire circle with side bandages. To ensure a good air wave in the system, do not press the rubber balloon against the chin by more than 1/3 of its volume. The air pressure in the system must be the same as the ambient air pressure. Before each recording, to equalize the pressure, the rubber tube is disconnected from the cylinder and the system is immediately resealed. The degree of pressing is determined by a graduated scale.
You can write down masticograms with a scribe on smoked paper, with a pencil or ink on white paper, using an ordinary kymog-raf, an electrokymograph, or specially designed writing apparatus for this. When using ink and paper tape during mastication, it is important to ensure that all details are recorded correctly and clearly. Care must be taken that the ink does not merge in the region of individual lines of curves, since the value of mastication lies in the fact that the details of the graphic picture can be used to judge the various movements of the lower jaw.
To ensure an identical recording of chewing, a number of conditions must be observed: throughout the entire period of research, the same speed of rotation of the kymograph drum must be maintained; the average duration of a single chewing wave should be 0.6-0.8 s; The feather of the Marey capsule should be installed in such a way that the amplitude of the waves fluctuates within 3-4 cm.
In order to approximate the method of determining the functional state of the dentition to physiological conditions, simultaneously with masticadiography, various solid, semi-solid and soft food substances were used for chewing samples: carrots, walnut kernels, sausage, crackers, soft bread and bread crust in a small amount.
The subject was asked to chew a nut kernel weighing 800 mg (the most common average weight of a nut) on a certain side until a swallowing reflex appeared. The patient spat out the resulting mass into a cup, rinsed his mouth with water, which he spat out into the same cup. The chewed mass was washed, dried and sieved through a sieve with round holes of 2.4 mm; the resulting residue was weighed. Next, a cracker weighing 500 mg and soft bread weighing 1 g, equal in volume to a nut kernel, were used. In parallel, mastication was carried out.
From the table, it can be seen that, depending on the state of the dento-maxillary system, the period from the beginning of chewing to swallowing and the size of the swallowed pieces change; as the condition of the dentition and jaw system deteriorates, the chewing time increases and the size of the food pieces increases. The difference in indicators is most clearly revealed when chewing crackers and weaker when chewing soft bread. With the help of a nut kernel chewing test, one can trace how the time and degree of chewing food change on individual pairs of antagonistic teeth. For example, the duration of chewing the nut kernel until the swallowing reflex appears in the area of the articulating molars is 40 s, and in the area of the canines - 180 s, i.e., as the chewing surface decreases, the chewing time lengthens.
Summarizing the above, it should be noted that the functional state of the dento-jaw system must be studied in a complex manner, taking into account motor and secretory reflexes.
Tests for accounting for these indicators should serve as food substances of different consistency; in this case, in addition to the degree of food grinding, the time of chewing and the formation of a food lump before swallowing and the number of chewing movements should be taken into account. The nature of chewing movements should be taken into account using other research methods. As an integrated indicator, a number of authors propose to calculate various chewing indices.
Electromyographic study of masticatory and facial muscles.Electromyography is a method of functional study of the muscular system, which allows you to graphically record muscle biopotentials. Biopotential - the potential difference between two points of a living tissue, reflecting its bioelectrical activity. Registration of biopotentials allows you to determine the state and functionality of various tissues. For this purpose, a multichannel electromyograph and special sensors are used - skin electrodes.
The functional activity of the muscles of the perioral region often changes due to malocclusion, bad habits, mouth breathing, improper swallowing, impaired speech, incorrect posture. Neurogenic and myogenic causes, in turn, can contribute to the emergence and development of malocclusion.
Electromyography should be performed with the assumption of diseases of the temporomandibular joint and the muscular system. By means of an electromyographic study, it is possible to determine the dysfunction of the masticatory and facial muscles during rest, tension and movements of the lower jaw, which are characteristic of various types of malocclusion.
It is desirable to register the activity of paired muscles at: 1) physiological rest; 2) stress, including compression of the dentition; 3) various movements of the lower jaw.
Electromyomasticography. FROMIn order to clarify the indicators of electrical oscillations of the masticatory muscles, corresponding to the individual phases of the masticatory period, the electromyography method was used in combination with mastication. With the help of a masticatiograph, the movements of the lower jaw are recorded, and with the help of diverting electrodes, biocurrents from the masticatory muscles are recorded. Using this method, it is possible to identify the insufficiency of the biopotentials of the masticatory muscles in certain areas of the masticogram. This method can be used to test the effectiveness of therapeutic measures.
Mastication dynamometry. The forces developed by the masticatory muscles during the compression of the dentition are determined using gnatodynamometers of various designs. The indicators of gnatho-dynamometry are judged by the sensations of patients associated with pain or an unpleasant feeling.
Such a subjective method of assessment leads to discrepancies in the indicators of gnathodynamometry.
The method for determining the strength of chewing - mastic-cyodynamometry (IS Rubinov, 1957) - is based on the use of natural nutrients of a certain hardness with simultaneous graphic registration of the chewing movements of the lower jaw. Preliminarily, with the help of a phagodynamometer, the efforts (in kilograms) required to grind a particular substance are determined. The name of the method - mastication dynamometry - indicates the measurement of the force of chewing, in contrast to gnathodynamometry - the measurement of the force of compression of the jaws. According to the nature of the records of chewing food substances with a known hardness, one can judge the intensity of chewing.
Myotonometry. Myotonometer measures the tone of masticatory and facial muscles. With various deviations from the norm, muscle tone changes. So, with complicated caries, the tone of the masticatory muscles at rest increases, which can serve as an additional symptom of dental disease. The device for measuring the tone of the masticatory muscles consists of a probe and a measuring scale in grams.
Using the method of myotonometry, it is possible to determine the indicators of the tone of the masticatory muscles in a state of physiological rest and during compression of the dentition. Muscle tone depends on the depth of the bite and varies according to the duration of bite separation from several hours and days to several weeks.
FROM In order to identify the relationship between the tone of the masticatory muscles proper and the force developed by them, a combination of myotonometry and gnatodynamometry was used. The subject was asked to squeeze the sensor of the electronic gnatodynamometer with a certain force with his teeth, while the muscle tone was measured with the myotonometer. The study showed that muscle tone does not increase strictly in proportion to the developed strength.
The data show that the relationship between the tone of the masticatory muscles proper and the force of compression of the dentition is subject to individual fluctuations and that there is no direct relationship between the degree of increase in the tone of the masticatory muscles proper and the force of compression of the dentition.
Myography. The function of the striated muscles is studied using various devices that record the thickening and reduction of the corresponding muscle groups during their contraction or relaxation. The myography method registers the activity of muscles associated with a change in their thickness during isotonic and isometric contractions. In the process of chewing, the thickness of the muscles changes due to an increase and decrease in their tone. The myography method is used to account for reflex contractions (thickening and thickening) of the masticatory muscles. The introduction of myography into the clinic is promising for recording the function of mimic muscles in normal and pathological conditions.
Rheographic research. Rheography is a method for studying pulse fluctuations in the blood-filling of vessels of various organs and tissues, based on graphic registration of changes in the total electrical resistance fabric. In dentistry, methods have been developed for studying blood circulation in the tooth - rheodentography, in periodontal tissues - rheoparodontography, and the periarticular region - rheoarthrography. Geography is used for early and differential diagnosis, evaluation of the effectiveness of the treatment of various diseases. Research is carried out with the help of rheographs - devices that allow you to register changes in the electrical resistance of tissues; and special sensors. The recording of the rheogram is carried out on writing instruments.
For reoparodontography, silver electrodes with an area of 3x5 mm, one of which is applied from the vestibular side (current), and the second (potential) - from the palatine or lingual side along the root of the tooth under study. This arrangement of electrodes is called transverse. The electrodes are fixed on the mucous membrane with medical glue or adhesive tape. Ground electrodes are attached to the earlobe. After connecting the sensors to the instruments and calibrating, they begin recording. At the same time, for the convenience of calculation, an electrocardiogram is recorded in lead II and a differential rheogram with a time constant of 10 s.
In the rheogram (RG), the ascending part is distinguished - the anacrota, the apex, the descending part - the catacrot, the incisura and the dicrotic zone. A qualitative assessment of the RG consists of a description of its main elements and features (features) 1) the characteristic of the ascending part (steep, flat, hump-shaped); 2) the shape of the apex (sharp, pointed, flat, arched, double-humped, domed, in the form of a cockscomb; 3) the nature of the descending part (flat, steep); 4) the presence of a dicrotic wave in severity (absent, smoothed, clearly expressed, located in the middle of the descending part, in the upper third, close to the base of the curve); 5) the presence and location of additional waves on the descending part (number, location below or above the dicrotic wave).
A typical RG configuration is characterized by a steep ascending part, a sharp apex, a smooth descending part with a discrotic wave in the middle and a clearly defined incisura. Quantitative analysis of RG is carried out using a triangle and a pencil. All amplitude indicators are expressed in millimeters, time - in seconds.
polarography. A kind of integral indicator that characterizes general state transcapillary exchange is the tension of oxygen (p02). Special devices - polarographs allow you to conduct research directly in the tissues of a living organism. The indicators depend on the nature and degree of pathological processes in the periodontium.
INITIAL DEFINITIONS
Orthopedic treatment of a patient implies not only the restoration of the anatomical shape of the crown parts of the teeth, dentition, but also the rehabilitation of the functions of biting, chewing, swallowing, aesthetic norms of a smile, face and diction.
Articulation is understood as all the positions of the lower jaw relative to the upper jaw that occur during its natural movements.
The main options for the positions of the lower jaw, which are of decisive importance in the clinic of orthopedic dentistry, are the following:
A) functional rest;
b) functional occlusions;
c) central ratio or central occlusion.
d) eccentric occlusions, eccentric ratios.
The position of the functional rest of the lower jaw is the position that it occupies in the case when the muscles that raise and lower it are in a state of functional rest.
Functional rest is a state of functional-tonic balance of the muscles that raise and lower the lower jaw, which occurs after the completion of chewing - swallowing, talking, specific to the masticatory muscles.
The muscles that raise and lower the lower jaw return to a state of functional balance every time after the end of the conversation: counting aloud.
This technique is used by dentists to determine, firstly, the state, and secondly, the height of the functional rest of the lower jaw.
The height of functional rest is the distance between two points plotted above and below the patient's oral fissure in the position of functional rest of the mandible.
By occlusion is meant the closure or contact between the dentition or individual teeth of the upper and lower jaws - a variant of articulation.
Functional occlusions are the positions of teeth closing when performing the functions of biting, chewing and swallowing.
The central ratio is the position of the lower jaw, which corresponds to the central occlusion, provided that there are a sufficient number and appropriate arrangement of teeth - antagonists.
If the dentition defects are located in such a way that there is not a single pair of antagonists, that is, with the 3rd group, or with complete adentia, with the 4th group of dentition defects according to Betelman, it is more correct to speak not about central occlusion, but about the central ratio .
The height of the central ratio or central occlusion is the distance between the alveolar processes or two points located above and below the oral fissure, in the position of the central ratio of the lower jaw.
Central occlusion - is called such a closing of the teeth, in which there is a maximum area of contacts between the antagonist teeth. In this position, there is a maximum and uniform contraction of the muscles that lift the lower jaw. The articular heads of the temporomandibular joints are located at the bases of the slopes of the articular tubercles at the so-called occlusal points.
Based on the mentioned definition of the concept of central occlusion by E.I. Gavrilov, they distinguish:<зубные>, <мышечные>And<суставные>signs of central occlusion.
The position of the central ratio of the jaws of the patient in the clinic is determined in order to reproduce it between plaster models of prosthetic beds and fix the position in the articulator.
Eccentric occlusions call all types of occlusions except the central one.
Eccentric ratios of the lower jaw - all positions of the lower jaw except for the central and functional rest.
Bite is called - a type of spatial arrangement of the dentition in the central occlusion.
One of the most important clinical stages of orthopedic treatment of a patient is to determine the position of the central occlusion (CO) of the patient's mandible.
Depending on the complexity of determining the position of the CO
A.I. Betelman identified four options:
In the first variant, when there are three or more pairs of antagonist teeth in the alveolar processes of the upper and lower jaws, located as follows: at least one in the anterior, and two others, in the lateral areas, from the position parameters of the CO, as a rule, only height. Gypsum models of prosthetic beds at the laboratory stage are compared in the position of the CO according to dental features and facets of worn occlusal surfaces of antagonistic teeth or using occlusal impressions;
Starting from the second variant of the complexity of determining the position of the CO, when less than three pairs of antagonists are located in the alveolar processes of the upper and lower jaws, it is necessary to first make bite patterns at the laboratory stage and determine the position of the CO at the clinical stage.
And only then, with the help of bite patterns, compare the models of prosthetic beds in the position of central occlusion (central ratio);
The most difficult option for determining the position of the CA of the jaws is the third, when there is not a single pair of antagonists or they are located only in two areas of the jaws) and the fourth (with complete adentia) options for the location of dentition defects.
In the second, third and fourth variants of the location of defects in the dentition of the upper and lower jaws, in order to determine the position of the CA, it is necessary in all cases to always make bite patterns (BM).
PS consists of a base, which can be made of base wax or plastic, and a roller, which is prepared from base wax or a mixture of wax and carborundum.
The PS requirements are as follows:
The PS basis should fit snugly against the working surface of the prosthetic bed model;
The edge of the basis of the PS - should not have sharp edges and be located in accordance with the boundaries of the prosthetic bed;
If the PS base is made of wax, then for the upper jaw it must be made from one, and for the lower jaw from two plates of base wax
PSh bases are made of wax, they must be reinforced with wire from the oral surface;
- the PS roller must be made monolithic from molten wax;
Roller PSh should be securely connected to the base with boiling wax;
The middle of the arc of the PS ridge should coincide with the top of the alveolar process of the model, except for the anterior segment of the upper jaw. In this area, the PS roller should be located 1/3 of the part anterior to the middle of the alveolar process;
The height of the PS roller in the anterior segment should be 1.5–2.0 cm, in the lateral segments, 0.8–1.0 cm;
The ridge of the upper PN in the distal segments should be beveled at an angle of 45° with respect to its occlusal surface.
The logical sequence of the clinical stages of determining the position of the central ratio of the jaws in the 3rd and 4th variants of the location of defects in the dentition according to A.I. Betelman is as follows:
At the very beginning, the height of the position of the CA is determined;
The sequence of stages for determining the position of the CA of the jaws:
The patient is seated in a dental chair in a comfortable position.
Two points are applied with a felt-tip pen or pen above and below the patient's mouth: one on the tip of the nose - the second on the protruding part of the chin.
The muscles that raise and lower the lower jaw are brought into a state of functional balance. To do this, they involve the patient in a short conversation or ask him to count aloud and then offer to close his lips without tension.
Measure the distance between these points and thus determine the height of the functional rest of the lower jaw. This height is then reduced by 2.0 mm, thus obtaining the height of the CS.
The vestibular surface of the ridge of the upper PS is modeled;
Determine the location of the level of the prosthetic surface of the roller of the upper PS;
The prosthetic surface of the upper PS ridge is modeled;
The location of the prosthetic surface is controlled using two spatulas, or the Sapozhnikov ruler, or the Larin apparatus, or the Zmiev apparatus;
Get an imprint of the prosthetic surface of the roller of the upper bite template on the roller of the lower PS;
Adjust the height of the roller of the lower PS under the control of the height of the position of the CA;
The vestibular surface of the ridge of the lower PS is modeled;
Determine and fix the position of the CA of the jaws using
PS;
The following lines are determined and drawn on the vestibular surfaces of the ridges: the cosmetic center of the face, smile, fangs;
They select the material, color, style of teeth for removable lamellar dentures or the color of the lining of a fixed structure.