RU2717276C1 - Method for determining degree of adaptation of dento-maxillary complex in dental treatment of dental defect or deformation - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to functional diagnostics, and can be used in practice in dental treatment aimed at eliminating defects and deformities of dentures. Method is implemented by measuring activity of chewing musculature with compression of jaws before and after dental treatment. Measurement is carried out using functional magnetic resonance tomography with alternation of jaw compressions 20–30 times and rest for 20–30 seconds in magnetic field power 1.5–3.0 T. Measuring the number of active neurons of the brain and in the lateration index of the right and left sides of tooth-jaw complex determined by formula: lateration index = (number of voxels on the left − number of voxels on the right) / (number of voxels on the left + number of voxels on the right), greater than 0.1 indicate a low degree of adaptation, and with lateration index less than 0.1 - high degree of adaptation.

EFFECT: method enables reducing the risk of possible complications on the structures of the dento-maxillofacial system by increasing the efficiency of assessing the results of dental treatment.

1 cl, 2 ex

Description

The present invention relates to medicine, namely to functional diagnostics and can be used in practice for dental treatment aimed at eliminating defects and deformations of the dentition.

A known method for assessing the degree of adaptation of the dentofacial complex during orthodontic treatment using cutaneous electromyography.

The essence of the method is to measure the bioelectric activity of chewing muscles before and after orthodontic treatment. Using surface electromyography, biopotentials (BP) are examined in the group of muscles that raise the lower jaw, the front parts of the right and left temporal, chewing muscles, in the right and left suprahyoid muscles, as well as in the cervical muscles, in the right and left sternocleidomastoid muscles .

Registration is carried out using a computerized electromyograph "Electromyograph BKN." The electromyograph has 16 differentiated inputs, which allows you to study simultaneously 8 pairs of muscles with a high degree of resolution (12 bits).

In the course of an electromyographic study, the following functional tests are used: Test 1: State of relative rest of the lower jaw (dentition not closed, lips slightly touching); Test 2: Physiological occlusion of the dentition (with the initial contact of the pairs of teeth of the antagonists, closing of the teeth without load).

Analyze the following indicators:

- total biopotential (BP) of the studied muscles of the right side - (muscles that lower and raise the lower jaw, sternocleidomastoid muscles);

- average - the biopotential of the studied muscles on the right (SBP) (the sum of the BP indicators of the right temporal, chewing, sublingual and sternocleidomastoid muscles, divided by 4) or on the left (the sum of the indicators of the 'BP of the right temporal, chewing, suprahyoid and sternocleidomastoid muscles, divided by 4);

- total biopotential (OBP) (μV) - the sum of all BP indicators of the muscles of the right and left sides;

- the percentage of BP of each muscle under study in OBP, measured in (%).

- an indicator of the maximum amplitude of biopotentials (MAX) (μV).

Uneven distribution in the percentage of biopotentials of the masticatory muscles on the right and left side before treatment may indicate functional disorders in the dento-maxillary system.

The symmetric distribution of the total biopotential of the masticatory muscles on the right side and the total biopotential on the left side after the orthodontic correction of occlusion anomalies indicates a high degree of adaptation of the dentofacial complex to the treatment.

An overbalance of the total biopotential of chewing muscles in one of the parties indicates an unfavorable course of adaptive processes [Nabiev N.V. Assessment of the bioelectric activity of the muscles of the maxillofacial region and its correction in patients with distal occlusion of the dentition: Dis. ... cand. honey. sciences. - M., 2011. - 145 p.].

The disadvantage of this method is the registration of the biopotential of the masticatory muscles without taking into account the functional state of the nerve centers that control the chewing act, reflecting only the adaptation in the peripheral parts of the neuro-muscular system, which cannot fully indicate the integration of the occlusal relationship achieved after dental treatment with the neuromuscular system of the tooth jaw complex.

The technical result of this invention is to increase the functional effect by increasing the effectiveness of evaluating the results of dental treatment, which will determine the degree of adaptation to the correction, thereby reducing the risk of possible complications from the structures of the dentofacial complex.

The technical result is achieved by the fact that in the method for determining the degree of adaptation of the dentofacial complex in the dental treatment of a defect or deformation of the dentition by measuring the activity of chewing muscles during compression of the jaws before and after dental treatment, a distinctive feature is that the determination is carried out using functional magnetic resonance tomography with alternating compression of the jaws 20-30 times and rest for 20-30 seconds in a magnetic field with a power of 1.5-3.0 T, measure the number of active brain neurons and with lateral index of the right and left sides of the dentofacial complex, determined by the formula

more than 0.1 indicate a low degree of adaptation, and with a lateration index less than 0.1 - a high degree of adaptation.

The method is as follows:

To perform functional magnetic resonance therapy (fMRI), the patient is placed in a tomograph. Rigid fixation of the head is used to reduce the number of distorted ones.

The survey consists of two phases.

In the first phase, during an fMRI mapping, an anatomical scan is performed to create a brain map, in the second phase, chewing is performed (compression of the jaws with a frequency of one compression in 1-2 seconds), while the patient hears two sound commands that start the process of compressing the jaws and symbolizing peace.

Thus, alternating active compression with rest periods occurs. The compression period, like the resting period lasts 20-30 seconds. The total number of periods is 20-15.

The criterion for the degree of adaptation of the dento-maxillary complex both before and after treatment is the symmetry of the right and left cerebral hemispheres, estimated by the value of the lateralization index according to the formula:

With a value of this index greater than 0.1, one can judge the asymmetric work of the cerebral hemispheres, which indicates a low degree of adaptation of the dento-maxillary complex and speaks of a one-sided type of chewing.

The lateration index less than 0.1 indicates a high degree of adaptation of the dentofacial complex and the symmetry of the masticatory muscles from the right and left sides.

Example 1

Patient P., 24 years old, was admitted to the clinic of FSBI “Central Scientific Research Institute of Hygiene and Genital Fibrillation” with complaints of curvature of the frontal group of teeth. In the process of clinical, anthropometric and cephalometric analysis, the diagnosis was established: Distal occlusion, deep incisal occlusion, narrowing of the dentoalveolar arches, crowded position of the incisors.

Before the start of orthodontic treatment, the patient underwent functional magnetic resonance imaging with imitation of chewing. The examination itself consisted of two phases. In the first phase, during an fMRI mapping, an anatomical scan was performed to create a brain map, in the second phase, chewing was simulated (jaw compression with a frequency of one compression in 1-2 seconds), while the patient heard two sound commands - “move” and “ Stop". The “move” command started the process of jaw compression, the “stop” command symbolized peace.

Thus, alternating active compression with rest periods occurred. The compression period, like the rest period, lasted 20-30 seconds. The total number of periods was 20-15.

The number of voxels in the sensorimotor cortex of the brain was found to be 102 on the left and 71 on the right. The lateralization index is 0.18.

In this case, the lateralization index value is more than 0.1, which indicates the asymmetric operation of the motor cortex, which may indicate a violation of the chewing function against an occlusion anomaly. After carrying out orthodontic treatment, which lasted 1.5 years, using a bracket system and TwinForce apparatus, orthodontic equipment was removed with fixation of fixed retainers from canine to canine on the upper and lower jaw, and removable retention devices for night wear were also made.

The next day after removing the equipment and fixing the retainers, the patient was re-examined for the activity of motor cortical neurons responsible for controlling chewing with fMRI.

The following results were obtained, the number of voxels in the sensorimotor cortex on the left is 62, on the right 58; the lateralization index is 0.03. According to fMRI, we can say that there was a bilateral decrease in the number of voxels and, as a result, activated neurons, as well as a decrease in the lateralization index.

A similar result after the end of the active phase of orthodontic treatment indicates a high degree of adaptation of the dentofacial complex to the treatment.

Based on this, one can not only ascertain the high degree of effectiveness of the treatment, but also reduce the period of the retention period to 6 months.

Example 2

Patient S., 35 years old, was admitted to the clinic of FSBI Central Research Institute for Hygiene and Chronic Illness with complaints of missing teeth 35.36, 26, 14.15, as well as tooth decay. In the course of the clinical and radiological examination, the diagnosis was established: Partial secondary adentia of the teeth 35.36, 26,14,15, tooth decay 34,37,12,11,16,25,27, 46,47. In connection with the clinical picture, the patient was offered the restoration of dentition defects with the help of ceramic-metal bridge structures.

Prior to the start of orthopedic treatment, an assessment was made of the activity of the sensorimotor cortex using fMRI according to the proposed method.

The following results were obtained:

- The number of voxels in the sensorimotor cortex was 126, to the right 92.

- The lateralization index is 0.16, which indicates the maladaptation of the dentofacial complex.

After orthopedic treatment, which eliminated defects in the dentition, a second mapping of the cerebral cortex was performed using fMRI.

The following data were obtained: the number of voxels in the sensorimotor cortex on the left and right decreased by 1.2 and 1.1 times, respectively, relative to the result before treatment and amounted to 99 voxels on the left and 87 voxels on the right, with a lateralization index of 0.06.

According to the results obtained after orthodontic treatment, we can talk about a high degree of adaptation of the dentofacial complex to the orthopedic treatment.

This method of determining the degree of adaptation of the dentofacial complex both before and after the end of dental treatment aimed at eliminating defects and deformations of the dentition, makes it possible to reduce the risk of possible complications.

Claims (3)

A method for determining the degree of adaptation of the dento-jaw complex in the dental treatment of a defect or deformation of the dentition by measuring the activity of the masticatory muscles during compression of the jaws before and after dental treatment, characterized in that the determination is carried out using functional magnetic resonance imaging with alternating compression of the jaws 20-30 once and at rest for 20-30 s in a magnetic field with a power of 1.5-3.0 T, measure the number of active neurons in the brain and with a lateration index of the right and left sides dentoalveolar complex, defined by the formula

more than 0.1 indicate a low degree of adaptation, and with a lateration index less than 0.1 - a high degree of adaptation.