RU2387408C2 - Method of evaluating chewing efficiency - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine and can be used for evaluation of patient's chewing efficiency both before planning orthopedic dental treatment, and after prosthetics with application of substituting orthopedic apparatuses. Functional (chewing) test is carried out. On the basis of chart with preliminarily calculated coefficients of chewing efficiency and taking into account coefficients of age and tooth row state, as well as type of substituting apparatus qualified efficiency of chewing is calculated.

EFFECT: method allows to determine chewing efficiency, individualise results of patients' chewing efficiency taking into account age and state of tooth rows.

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Description

The invention relates to medicine, namely to orthopedic dentistry, and can be used to study the condition of the masticatory and speech apparatus and to monitor the effectiveness of chewing before and after orthopedic dental treatment.

Known functional test of Christiansen (Gavrilov E.I., Alshits I.M. "Orthopedic Dentistry" M .: Medicine, 1970), The patient was given 5 g of hazelnut or coconut. After 50 chewing movements, the patient spat out the food mass, dried it and sieved it through a 2.4 mm sieve. Chewing efficacy was calculated by the proportion of food residue on the sieve.

The indicated sample was modified by S.E. Gelman (Gavrilov E.I., Alshits I.M. "Orthopedic Dentistry" M .: Medicine, 1970), which used almonds instead of hazelnuts, and instead of 50 chewing movements, offered to chew for 50 seconds. The rest of the procedure was the same.

Both samples are modifications, without fundamentally different from each other.

However, the complexity and laboriousness of the manipulations, the need to rinse the oral cavity and disinfect the sample after removing it from the oral cavity, as well as the possible change in particle size after drying, make this sample inapplicable in everyday practice and has a high degree of total error.

A more recent method is to evaluate the effectiveness of chewing according to I.S. Rubinov (Gavrilov E.I., Alshits I.M. "Orthopedic Dentistry" M .: Medicine, 1970). The subject was offered 0.8 g of almonds, which is approximately equal to the mass of one of its kernels. The patient chewed the nut until a swallowing reflex appeared. As soon as there was a desire to swallow a chewed nut, he was offered to spit the contents, the remains of the nut were washed out of the oral cavity.

The resulting substance was filtered through cheesecloth over a clean vessel. After the liquid drained from the gauze, the gauze was deployed on a flat bath and dried in a water bath. It was not recommended to use a drying cabinet, as this caused wrinkling and changing the shape of the resulting particles. The mass was considered dried if, when kneading with the fingers of a doctor, it gave a feeling of dryness and easily crumbled. Then the mass was sieved through a metal sieve with holes with a diameter of 2.4 mm. Part of the mass remaining in the sieve was carefully sprinkled on clean glass and weighed to an accuracy of 0.01 g.

The chewing time of the nut was counted by the stopwatch. As a result of the test, two indicators were obtained: the amount in percent of chewed food and the time of chewing. Studies by I.S.Rubinov showed that with an orthognathic bite and intact dentition, the nut kernel is completely chewed in 14 seconds. With the loss of teeth, chewing time lengthens, and at the same time, the residue on the sieve increases. This chewing test made it possible to carry out a more in-depth study of the patient's masticatory-speech apparatus, as well as to monitor the masticatory effectiveness before and after orthopedic treatment. However, the complexity, complexity, multi-stage and duration of this procedure remained. A specially equipped laboratory was required for the test. This significantly complicated the widespread use of chewing samples in the practice of an orthopedic dentist. They ceased to use it, although the assessment of chewing effectiveness is very relevant for various kinds of examinations.

The task is to develop a fairly simple method of rapid diagnosis to determine the effectiveness of chewing, which allows to individualize the results taking into account the age and condition of the dentition.

This problem is solved due to the fact that in a method of evaluating the effectiveness of chewing, including chewing a patient 0.5-1 g of food irritant before the swallowing reflex and determining the time spent on chewing, before starting to evaluate the effectiveness of chewing in a particular patient, the time spent on chewing a food irritant before a swallowing reflex appears in a group of patients with intact dentition and compile a table of correspondence between chewing time and chewing effectiveness, expert mentally determine the coefficients for age (K ₁₎ and the state of dentition (K _2). Then, according to the table, the preliminary chewing efficiency (E _pred. ) In a particular patient is determined and the specified chewing effectiveness (E _pred. ) _{Is calculated} by the formula:

E _ref. = E _ant. × K ₁ × K ₂ .

The method is as follows.

Experimentally, we measure the effectiveness of chewing in the following groups of patients:

1) patients with intact dentition;

2) patients with short bridges (including implants);

3) patients with long bridges (including implants);

4) patients with partial removable dentures;

5) patients with complete removable dentures.

In this case, the first three groups of patients are divided into three subgroups each, depending on age. The first group includes people under 39 years old, the second - from 40 to 59, the third - over 60 years old.

The average chewing efficiency in each group is determined.

During the examination of 250 patients aged 18 to 70 years (average age 36 ± 2 years), it was found that with a normal bite and healthy dentition, a food irritant (almond kernel, cube of raw carrots) weighing from 0.5 to 1 g completely chewed on average in 16.0 seconds. The chewing efficiency is equal to 100%. For this indicator, as a variant of the norm, the spread interval equal to σ = ± 2 was taken into account. Thus, the scatter of normal values for 99.9% of the population was from 12 to 20 seconds. With an increase in the time spent chewing a food irritant, the effectiveness of chewing food decreases accordingly.

On the basis of the obtained data, a table has been developed that compares the time of chewing food (in s) and the effectiveness of chewing (in%).

Chewing time, s Chewing efficiency,% 16 and less one hundred 17 94.1 eighteen 88.9 19 84.2 twenty 80.0 21 76,2 22 72.7 23 69.6 24 66.7 25 64.0 26 61.5 27 59.3 28 57.1 29th 55,2 thirty 53.3 31 51.6 32 50,0

There was a slight decrease in the effectiveness of chewing in patients with tooth loss, replaced by various designs of dentures, as compared with individuals with intact dentitions, as well as in elderly patients, due to a decrease in the adaptive capacity of the masticatory system, compared with young people. This difference in indicators served as the basis for calculating the correction factors. The coefficients were calculated so that the average chewing efficiency obtained for each group, multiplied by the coefficient, gave 100%. As a result, received:

1. The correction factor for age (K ₁ ):

- up to 39 years old K ₁ = 1,0

- 40-59 years old K ₁ = 1.05

- 60 years and older K ₁ = 1,1

2. The correction factor for the condition of the dentition (K ₂ )

In the presence of healthy dentitions, single artificial crowns, bridges of short and medium length, including implant dentures, K ₂ = 1,0.

In the presence of long bridges, including implant ones, K ₂ = 1.05.

In the presence of partial removable dentures - K ₂ = 1,1.

In the presence of partial removable dentures with a single standing retained teeth, full removable dentures - K ₂ = 1,15.

The adjusted chewing efficiency is calculated by the formula:

E _ref. = E _ant. × K ₁ × K ₂ ,

where K ₁ - age-related coefficient of adjustment for age;

K ₂ - correction factor for the condition of the dentition.

The preliminary effectiveness of chewing (E _pred. ) _Is calculated as follows. The patient receives a portion of the food irritant and begins to chew it until a swallowing reflex occurs, an irresistible desire to swallow a food lump. The time elapsed from the beginning of chewing until the desire to swallow appears is recorded by the doctor's assistant using a stopwatch.

Example.

Patient G., 58 years old. He went to the clinic of orthopedic dentistry with a complaint of difficulty chewing food.

Diagnosis: partial loss of teeth in the upper and lower jaws (bilateral end defects of the dentition of the lower jaw, included defects of the anterior and lateral parts of the dentition of the upper jaw).

To assess the effectiveness of chewing, the patient was asked to chew 0.7 g of almond nut until the swallowing reflex appears. The time spent on chewing, which the patient noted on his own using a stopwatch, was 31 seconds. According to the developed table, a preliminary chewing efficiency (E _pred. ) Was obtained, which amounted to 51.6%. Further, according to the formula:

E _ref. = E _ant. × K ₁ × K ₂

the specified chewing efficiency has been obtained: E _ref. = 51.6 × 1.05 × 1.0 = 54.18%.

After orthopedic treatment - the application of partial removable laminar dentures on the upper and lower jaws - the chewing time of 0.7 g of almond nut was 26 seconds, and the preliminary chewing efficiency was 61.5%. Further, according to the formula E _ref. = E _ant. × K ₁ × K ₂ the specified chewing efficiency was obtained: E _ref. = 61.5 × 1.05 × 1.1 = 71.03%. The increase in the chewing test indicates a high functional quality of the prosthesis, as confirmed by clinical studies.

Thus, the advantages of the proposed method is:

1) a small amount of time spent on the test (no more than 15 minutes per patient, including instructing the latter);

2) taking into account age and morphofunctional corrections, allowing to individualize the results;

4) convenience, simplicity and high speed of calculating the effectiveness of chewing (by using the attached table and calculation formula);

5) lack of need for special equipment;

6) refusal of labor-intensive standard procedures with potentially high errors.

7) simplification of the known test (Rubinov) with high accuracy and information content of the results.

Claims (1)

A method for evaluating chewing effectiveness, including chewing a patient with 0.5-1 g of a food irritant until a swallowing reflex occurs and determining the time spent on chewing, characterized in that before starting to evaluate the chewing effectiveness of a particular patient, the chewing time of a food irritant before the swallowing reflex appears in groups of patients with intact dentition and compile a table of chewing effectiveness depending on the time spent on chewing, experimentally determined t coefficients chewing efficacy for patients of various age groups K ₁ and with various embodiments of state dentition K _2, according to the table determine the provisional masticatory efficiency (E _Pre.) of a specific patient is selected for this patient coefficients K ₁ and K ₂ and determining a refined masticatory efficiency ( E _ref. ) By the formula E _ref. = E _ant. K ₁ K ₂ .