In the article, we will consider what chewing effectiveness according to Agapov is.
This concept reflects the most important indicators of the condition of the teeth and jaw structure. This is the strength of the muscular endings of the lower jaw, performing chewing movements. It is necessary for crushing, biting and crushing food. This indicator is measured in individual areas of the dentition. There is also such a thing as gnatodynamometry, which is a technique for measuring the pressure of muscle fibers of the chewing apparatus, as well as the resistance of dental tissues to compression of the jaws. This method is implemented using a special device called a gnatodynamometer.
Anatomical features of the teeth
Most dentists who work with this topic perceive 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 the following anatomical features of the teeth:
- surface size;
- number of roots;
- the presence of hillocks;
- distance from the angle of the lower jaw;
- periodontal features
- cross sections of the neck.
Consider chewing effectiveness according to Agapov in more detail.
Determination methods
Measurement of voltage 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.
In the sensor, which attaches to the microammeter, is a brass plate. A man is sitting in a chair. It is very important that he is comfortable and psychologically comfortable. Between the jaws, a specialist inserts a nozzle into the mouth and the patient compresses it with his teeth until pain occurs. Thus, the chewing pressure is displayed on the scale of the device at this moment. Sensor values are fixed. Gnatodynamic indicators may depend on many factors:
- gender of a person;
- individual characteristics;
- existing diseases (periodontal disease, periodontitis and others);
- partial tooth loss;
- age.
Averages
Agapov chewing efficacy values on the device are shown in kilograms. Average values vary within 15-36 for anterior teeth and 45-78 kg for molars. They are important for optimizing prosthetics, as they determine the periodontal sensitivity to stress, and help establish the design of a particular prosthesis.
The average values of chewing pressure were established, which are taken as the basis for observations and the correspondence of the load of periodontal force: for women on 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.
How to consider chewing effectiveness according to Agapov, many are interested.
Pressure on teeth in kilograms
According to the works of N. I. Agapov, there are tables with the distribution of the chewing force on each tooth, however, it should be borne in mind that they are all approximate. Endurance of periodontal tissues as a whole (936 kg in women and 1408 kg in men) is almost never realized, since the greatest power of contractions of the masticatory apparatus is 390 kg. Gnatometry is very rarely used in modern dentistry due to the following disadvantages:
- only vertical pressure is determined, but horizontal force is not taken into account;
- the result cannot be absolutely accurate;
- quick deformation of the spring;
- the result is affected by the patient’s psychosomatic state, which may change throughout the day.
Calculation principles
The method of N. I. Agapov is based on the calculation of the chewing power of each tooth as a percentage of the entire jaw apparatus. As a rule, to determine the violations using a total count of the number of teeth. N. I. Agapov believes this is fundamentally wrong, because their effective and power value varies significantly. He developed a special table in which the coefficients are distributed between each tooth.
N.I. Agapov took the masticatory efficiency of the entire masticatory apparatus for 100% and calculated the masticatory pressure of each tooth in percent, having obtained masticatory effectiveness by adding the masticatory ratios of the remaining teeth.
The main amendment of this author is his conclusion that the teeth are most effective only in pairs, and those that have lost antagonists, practically lose their basic functions. This means that if one tooth is missing, then the absence of two at once is ascertained. And the calculation of masticatory effectiveness, respectively, must be carried out according to the number of paired teeth. When applying this amendment, the indicators are completely different.
Without correction, the masticatory efficiency is 50%, while when using the N. I. Agapov amendment, the masticatory effectiveness is 0. In the event that the patient does not have a single pair of antagonizing teeth.
What else is taken into account in assessing chewing effectiveness according to Agapov?
Oxman Amendments
Oksman I.M. pointed out the necessity and importance of taking into account the activity of existing teeth, taking into account their mobility. In the first stage of pathological mobility, chewing effectiveness corresponds to 100%. In the second stage - 50%, in the third - state its complete absence. The last degree also includes teeth that are affected by periodontitis. Oksman, researching the development of Agapov, recorded teeth-antagonists in the form of fractions. Indicators that mean a loss of chewing effectiveness are recorded in the following order: in the numerator - maxillary value, in the denominator - mandibular. According to this scheme, it is most convenient for a specialist to imagine the state of the chewing apparatus. Gnatodynamic values are important in dental prosthetics and in orthodontics. They may be affected by:
- psychological state of the patient;
- measurement reactivity;
- compensatory ability of periodontal receptors and many other factors.
Using gnatometry, the following is carried out: monitoring the dynamics of therapeutic procedures and the functionality of implants, measuring pressure between pairs of teeth, determining the functionality of prostheses.
Static systems in the form of tables
To calculate the periodontal endurance and strength of each tooth during chewing, certain tables are proposed, which are called static systems for determining chewing effectiveness. 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 decoding 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 that were developed according to a single principle (Wustrow, Duchange, Mamlock, etc.). In domestic practice, a static system for calculating chewing effectiveness according to Agapov was widely used.
Chewing Odds - Transcript
N.I. Agapov took the effectiveness of the dental apparatus for 100%, and for the constant 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 amended this table, recommending the presence of antagonist teeth when calculating the masticatory effectiveness of the dentition.
In determining chewing effectiveness according to Agapov, the value of each of the teeth is constant and does not in any way depend on the condition of the periodontium. For example, the role of a 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 disassembled. Nevertheless, there have been attempts to create new systems in which the periodontal force to pressure during chewing depended on the degree of its defeat. In this case, an assessment is given to each tooth, including the wisdom tooth. In this case, 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 weak in functional terms were taken as a unit. Central incisors and fangs - for two units, the first molars for six, premolars for three. As a result of such calculations, a new table was compiled.
Loss of chewing effectiveness according to Agapov
Evaluation of these indicators is used when passing the draft medical commission. This method is not used to establish the category of fitness for military service. Young people who have the following limited qualifications for military service are those who:
- 10 or more teeth are missing on one jaw, or they are replaced by a removable denture;
- on one jaw there are no 8 molars;
- 4 molars on both jaws are missing from different sides, or they are replaced by their removable dentures.