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 gnatodynamometry, which is a technique for measuring the pressure of 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 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 a similarpressure, doctors are guided by such anatomical features of the teeth:
- surface size;
- number of roots;
- presence of bumps;
- distance from the angle of the lower jaw;
- periodontal features
- cross sections of the neck.
Let's consider chewing efficiency according to Agapov in more detail.
Determination methods
Measurement of stress 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 is attached to the microammeter, there is a brass plate. 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 occurs. Thus, chewing pressure is displayed on the scale of the device at this moment. The sensor values are fixed. Gnathodinamometric indicators may depend on many factors:
- person's gender;
- special features;
- 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 are essenti alto 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 are established, which are 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 the molars - 50-75 kg.
How to calculate chewing efficiency according to Agapov is interesting to many.
Teeth pressure 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 vertical pressure is determined, but horizontal force is not taken into account;
- result cannot be absolutely accurate;
- quick spring deformation;
- the result is influenced by the psychosomatic state of the patient, which may change during the day.
Calculation principles
N. I. Agapov's method is based on the calculation of the chewing force of each tooth as a percentage of the entire jaw apparatus. As a rule, a general count of the number ofteeth. 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, having obtained the chewing efficiency by adding the chewing coefficients of the remaining teeth.
The main correction 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 correction, chewing efficiency is 0. In the event that the patient does not have a single pair of antagonistic teeth.
What else is taken into account in the assessment of chewing efficiency according to Agapov?
Oxman 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 -state its complete absence. 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:
- psychological state of the patient;
- measurement reactivity;
- compensatory ability of periodontal receptors and numerous other factors.
With the help of gnathometry, 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 tabular form
To calculate the endurance of the periodontium and the strength of each tooth during chewing, certain tables are 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 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,on 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, the static system for calculating chewing efficiency according to Agapov has become widespread.
Chewing odds - transcript
N. I. Agapov took the effectiveness 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 amended 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 periodontium to 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. Centralincisors 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 assessment of these indicators is used when passing the draft medical board. This method is not used to determine the category of fitness for 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;
- 4 molars are missing on both jaws from different sides, or they are replaced by their removable dentures.
