RU182498U1 - STRESS-INDUCING DEVICE FOR FORMING NON-PHYSIOLOGICAL JAW OCCLUSION IN AN EXPERIMENTAL ANIMAL - Google Patents

Abstract

The utility model relates to medical equipment used in dentistry and pathological physiology, in particular, to devices designed to create models of a pathophysiological experiment on animals, and can be used to form nonphysiological occlusion of the oral cavity. The device consists of a fixing vest equipped with two openings for front paws and one hole for the neck with a fastener on the contact tape, with a metal ring sewn into the collar, to which the round aramid 1 mm thick thread with two symmetrically located silicone stops and a metal ball with a diameter of 3, 5 or 7 mm, having a hole in the middle of such a diameter that allows it to move freely along the thread. The device allows the formation of non-physiological occlusion in an experimental animal (rat) without prejudice its life and freedom of movement, characterized by ease of manufacture and use for a long period of time. 4 of FIG.

Description

The utility model relates to medical equipment, applied dentistry and pathological physiology, in particular, to devices designed to create models of a pathophysiological experiment on animals and can be used to form non-physiological occlusion of the oral cavity.

A modern understanding of occlusion includes the relationship of teeth, chewing muscles and temporomandibular joints with function and dysfunction. Occlusion is very important in order to provide the patient with comprehensive treatment. Stable physiological occlusion is provided by multiple uniform fissure-tubercle contacts of the posterior teeth, which are characterized by the presence on the occlusal surface of the contacts of the slopes of the antagonist tubercles. Correct occlusal contacts ensure axial load of the teeth, create stable central occlusion and exclude periodontal overload [Gross M. D., Matthews J. D. Normalization of occlusion / Gross M.D., Mathews J.D. // Occlusion in restorative dentistry. Churchill livingstone, 1982. - M .: Medicine, 1986. - 288 p.].

Violation of occlusion can occur with partial loss of teeth, especially the lateral group of teeth, when the mastication of the masticatory load occurs, as a result of which periodontal overload of the remaining teeth may occur, dentoalveolar deformation of the jaw, parafunction of the masticatory muscles. These pathological changes lead to periodontitis, dysfunction of the temporomandibular joint (TMJ) and entail a lateral or distal shift of the lower jaw [Khvatova V.A. Occlusal tires - the current state of the problem // Maestro of Dentistry. - 2007. - No. 4. - S. 52-56].

When replacing defects in the dentition without taking these factors into account, dysfunctional violations of the elements of the temporomandibular joints and chewing muscles occur, which leads to breakage of removable orthopedic structures, chips of ceramic-metal crowns, an increase in the adaptation time to manufactured dentures, and tooth overload leads to progression of periodontal disease . Therefore, it is important to include measures to normalize the function of the masticatory muscles and position of the lower jaw, as well as measures to prevent displacement of the lower jaw in the algorithm for the comprehensive treatment of patients with partial tooth loss [Klineberg I., Jager R. Occlusion and clinical practice. - 2nd ed. - M.: MEDpress-inform, 2008. - 200 p.].

On the other hand, the existing methods and means of solving the problem of normalizing occlusion, based on the use of tooth mouth guards and / or tires, provide only for the restoration of uniform fissure-tubercular contacts in the area of hard tissues of the posterior teeth, but do not take into account the pathological changes that occur in soft tissues and periodontal surrounding the tooth. Such therapy, carried out without taking into account metabolic and structural changes in periodontal tissues, the influence of a stress factor, often does more harm than good.

For the scientific study of such pathological changes, the development of methods and means (including pharmacological) for their correction, it is necessary to understand the pathophysiological mechanisms underlying the formation of non-physiological (traumatic) occlusion.

An animal experiment is considered the generally accepted basic principle of research in medicine, as a result of which one or another pathology is recreated, which allows a comprehensive study of the problem facing science.

The developed stress-inducing device for the formation of non-physiological occlusion of the jaws in an experimental animal is intended for such a purpose, namely, for a comprehensive study of pathological changes in the tissues of the oral cavity, occurring both at the local (for example, periodontal tissues) and systemic levels (for example , in the dentition of the body) in violation of physiological occlusion.

Realization of the goal in an experimental animal (rat) has a number of difficulties: direct prototyping of the tooth splints and mouth guards used in humans is unacceptable for animals, since it is caused by the structural features of the rat’s dentofacial apparatus (cutting, and not rubbing, surfaces of lateral teeth, as in humans), high the cost and complexity of manufacturing individual mouthguards or tires for each animal and the inability to dynamically monitor the condition of the dentition of the animal.

A bridle is known from the prior art, a part of a horse harness - belts of a special design worn on a horse’s head with bit and reins combined in a single unit, serving to control the horse.

The disadvantage for using the reins in the experiment is the difficulty of extrapolating the structure to an incomparable experimental animal (rat, for example), as well as the need to control each animal individually.

Close enough to the proposed technical solution is a gag - a piece of wood or a rag, forcibly inserted into the mouth of an animal or person in order to prevent it from biting or screaming. There are gags of different designs, they can be made of different materials, for example, leather, plastic, rubber, they have, as a rule, limiting (for example, ball) and fixing (for example, strap) elements in their design (https: // ru. wikipedia.org/wiki/%D0%9A%D0%BB%D1%8F%D0%BF).

A disadvantage of the known design is the difficulty of using a gag when eating food and water, which can lead to premature death of the experimental animal, as well as the lack of a system for attaching it to the body of the animal.

Known gag designs do not allow them to be fixed for a long time in an experimental animal, since the rat can easily get rid of any foreign bodies in the mouth with the help of its forepaws. Restriction of movement by binding or another type of fixation of the limbs of an experimental animal will reduce the purity of the experiment and will not allow to study the stress-inducing factor at the level required to solve the goal.

The well-known TRIXIE harness vest (TRIXY) for guinea pig / rat, the kit includes a vest (vest) and a leash with a carabiner (http://www.krysota.ru/product_info_php?products_id=3514).

The vest is fixed on the animal in 2 places: under the throat so that the animal does not reach it with its teeth and paws and on its stomach. Both fastenings are adjustable, the use of a vest is possible for an animal of any age. The vest is fastened with Velcro (contact tape), which are made of high-quality synthetic material, which greatly lengthens the life of the device.

The disadvantages of the harness-vest are the design features that do not allow it to be used to solve the goal without making significant changes to its device.

The search results showed that it is not enough for a specialist to simply combine the devices closest in technical essence - a gag and a vest, which clearly follow from the prior art, since to achieve this goal a significant improvement in the known constructions is required, changing, in essence, their original purpose .

The objective of the proposed technical solution is the non-invasive provision of non-physiological occlusion in an experimental animal (rat) without prejudice to its vital functions and freedom of movement, characterized by ease of manufacture and use over a long period of time.

The technical result achieved in solving this problem is expressed in the possibility of modeling the pathology of periodontal tissues caused by the action of a stress-inducing factor in the form of non-physiological occlusion in an experimental animal (rat).

The problem is solved due to the fact that the stress-inducing device for the formation of non-physiological occlusion of the jaws of an experimental rat, including a fixing vest, equipped with two holes for the front legs and one hole for the neck with a fastener on the contact tape, additionally has a metal ring sewn into a collar to which a round aramid thread 1 mm thick with two symmetrically located silicone stops and a metal ball with a hole in the middle is rigidly attached and of a diameter that allows it to move freely along the thread.

In FIG. 1 shows the main elements of the device.

In FIG. 2 - a device in working condition, installed in an experimental animal.

In FIG. 3 is an electron microscopic image of degenerative processes in solid periodontal tissues in experimental animals 30 days after installation of the device. The number 1 indicates the edges of the dental alveoli.

In FIG. 4 is an electron microscopic image of dystrophic processes in periodontal hard tissues in experimental animals 60 days after installation of the device. The numbers 1 indicate the edges of the dental alveoli, the numbers 2 indicate the abrasion of the cutting edges of the teeth and the inter-tubercle contacts, the numbers 3 indicate the spread of the pathological process of destruction on the alveolar bone.

Thus, the proposed stress-inducing device for the formation of non-physiological occlusion of the jaws in an experimental rat is made in the form of a metal ball (1) having a hole in the middle (2) through which a round aramid thread (3) 1 mm thick with two symmetrically positioned silicone limiters (4), which is rigidly attached to a metal ring (5), sewn into the collar (6) of the fixing vest (7) with a fastener on the contact tape (8), equipped with two holes (9) for the forepaws and one m hole (10) for the neck. In accordance with the age or size of the experimental animal, the diameter of the ball may be different.

A brief description of the elements used in the device.

Ball - a metal ball made of a biological neutral metal, for example, titanium, which has a hole in the middle through which an aramid thread freely passes. Such a design allows the ball to move freely in the animal’s mouth, however, it does not allow it to be spit out or gnawed, titanium does not oxidize in the oral cavity and does not affect important biochemical parameters of saliva.

Aramid thread is several times stronger than piano steel, which with its thickness of 1 mm already excludes it from being bitten by the teeth of an animal, is completely biologically compatible with natural bone and soft tissues of the oral cavity, plastic and affordable. The position of the ball on the aramid filament is regulated by two symmetrically positioned silicone stops so that they are always located outside at the level of the cheeks, and the metal ball is always located in the mouth of the experimental animal in the sky between the dentition at the level of the lateral molars.

The vest is made of synthetic material, it is a single fixing structure together with a metal ring sewn into the collar, the size of which corresponds to the size of the rat’s head, to which a 1 mm thick aramid thread with two symmetrically located silicone stoppers is rigidly attached, passed freely through the hole in the metal ball. The vest is worn by threading the animal’s head and paws into the corresponding technological holes, it is additionally equipped with a convenient wide fastener on the contact tape, with fixation on the back of the animal, which allows you to adjust the degree of fixation of the vest on the body of the experimental animal, if necessary, and does not allow the animal to unfasten it.

A comparative analysis of the features of the claimed solution with the features of the prototype and the closest analogues demonstrates the compliance of the claimed solution with the criteria of "novelty" and "industrial applicability".

The search results showed that the claimed utility model does not derive explicitly from the prior art for the specialist, since the influence of the claimed technical features, provided for by the essential features, is not revealed from the prior art, which provides a positive reaction to the solution of the technical problem - modeling of periodontal tissue pathology caused by exposure to a stress-inducing factor in the form of non-physiological occlusion in an experimental rat.

Stress-inducing device for the formation of non-physiological occlusion of the jaws in an experimental rat is used as follows.

The device for forming non-physiological occlusion of the jaws, pre-selected in size depending on the age and physique of the experimental rat, is put on through the open fixing vest, first passing the head through a metal ring sewn into the collar, and a metal ball is moved in, moving freely on a round aramid thread in the animal’s mouth . Two symmetrically positioned silicone stops are installed at the cheeks level, restricting the ball to the mouth only, then tighten the fixing vest with a fastener on the contact tape on the back of the animal so that the round aramid thread is at the level of the corners of the mouth and the metal ball is in the mouth in the area of the sky between the dentitions at the level of the lateral molars.

After placing the device on the body of an experimental rat, it is placed in a cage.

Due to the claimed design of the device, the animal can move freely, but cannot get rid of any element of the device even with the use of paws, nor can it spit out the ball through the corner of the mouth due to the lack of appropriate facial muscles and the presence of two symmetrically located silicone stops on the aramid thread, also can gnaw aramid thread due to its special strength.

The duration of the experiment is not limited: with the device fixed on the body and in the mouth, the rat drinks, takes food, however, due to the design features of the device, it cannot chew on both sides of the jaw at the same time (the metal ball in the mouth interferes), therefore I chew on one, then on the other side.

Continuously rolling the ball in the mouth, and not being able to get rid of it, the experimental animal experiences constant stress, which serves as a trigger for the first formation of nonphysiological occlusion and then inflammation of periodontal tissues (periodontitis), and the device provides a non-invasive formation of the pathology under study without compromising vital activity and freedom of movement of the animal. In addition, the developed device is characterized by ease of manufacture, low cost of materials and the possibility of repeated use over a long period of time in various experimental studies for the formation of non-physiological occlusion of the jaw under constant stress.

The developed stress-inducing device for the formation of nonphysiological occlusion of the jaws in an experimental rat was tested in vivarium on the basis of the Federal State Budgetary Educational Institution of Higher Education "Stavropol State Medical University" of the Ministry of Health of Russia (FSBEI HE STMU of the Ministry of Health of the Russian Federation).

The animal experiment was conducted in accordance with the principles of good laboratory practice (National Standard "Principles of Good Laboratory Practice" GOST R 53434-2009) and the positive conclusion of the ethics committee of STMU No. 34 dated 04/12/2017.

The studies were carried out on white laboratory rats (40 animals in total), which are divided into 4 equal groups of 10 individuals: 1st — intact animals (without device); 2nd group - animals with a installed stress-inducing device for the formation of non-physiological occlusion of the jaws for 15 days; Group 3 - animals with a installed stress-inducing device for the formation of non-physiological occlusion of the jaws for 30 days, group 4 - animals with a installed stress-inducing device for the formation of non-physiological occlusion of the jaws for 60 days.

Animals were removed from the experiment by an overdose of ether. Morphological changes in periodontal tissues were evaluated by preparations stained with hematoxylin and eosin and Masson.

Macrodrugs were investigated using a JSM-T300 scanning electron microscope (Japan) with the operating mode: accelerating voltage - 20 KV; current strength - (2.9-3.1) × 10 ¹⁰ A with an increase of - × 50, × 500.

Microscopy of histological sections was carried out on a digital microscope with an integrated Olympus BX45 camera. Morphometric studies were performed using the Video Test Morphology 5.1 program for Windows. The obtained digital data were analyzed using the statistical method of t-student test in the program Primer of Biostatistics 4.03 for Windows. The differences were considered significant at p <0.05.

As the results of the study showed, the use of a stress-inducing device leads to the formation of non-physiological occlusion of the jaws by the 30th day of the experiment, and pathological inflammatory changes in periodontal tissues, characterized by gum bleeding, mobility, are recorded by 60 knocks in the experimental animal against the background of the formed non-physiological occlusion. chewing teeth, plaque and pathological pockets, a depth of 5 mm.

With the short-term use of a stress-inducing device (15 days), structural changes occurred in the periodontal soft tissues of experimental animals, which were accompanied by loss of elasticity of muscle fibers and blood vessel walls due to the release of fluid from myocytes with the inclusion of protein components. However, the manifestations of generalized edema of the attached gums were not critical. Changes in the ultrastructure of mitochondria were also observed: moderate swelling, partial vacuolization, compression of the mitochondrial matrix and membranes. Such changes are evidence of mitochondrial dysfunction, which is characteristic for the development of a stress reaction. There was an increase in the number of dilated tubules of the sarcoplasmic reticulum, which can be considered as one of the initial stages of the formation of periodontal tissue damage.

Studies carried out by scanning electron microscopy showed that prolonged use of the developed device leads to the formation of nonphysiological occlusion in the form of abrasion of the cutting edges of teeth and inter-tubercle contacts by the 30th day of the experiment, but is especially pronounced by the observation period of 60 days. By this time, there is a pronounced thinning and destruction of the edges of the dental alveoli (indicated by the number 1 in Fig. 3 and Fig. 4), as well as the spread of the pathological process of destruction further on the alveolar bone (indicated by the number 3 in Fig. 4).

The structure of hard periodontal and tooth tissues in rats is depicted in FIG. 3 and FIG. four.

In FIG. 3 - electron-microscopic image of dystrophic processes in periodontal hard tissues (1) in experimental animals of the 3rd group (30 days after installation of the device).

In FIG. 4 - electron-microscopic image of dystrophic processes in periodontal hard tissues (1), the formation of nonphysiological occlusion in the form of abrasion of the cutting edges of teeth and inter-tubercle contacts (2) and the transition of the pathological process to the alveolar bone (3) and in experimental animals of the 4th group ( 60 days after the installation of the device).

Thus, the electron microscopic and histological results of an experimental study using the developed stress-inducing device for the formation of non-physiological occlusion of the jaws confirmed the possibility of efficient reproduction of non-invasive experimental non-physiological occlusion and inflammation of periodontal tissues without compromising the vital functions and freedom of movement of the animal, guaranteeing high accuracy and purity of the obtained scientific evidence with precision and evidence ny character.

The practical effectiveness of the developed stress-inducing device for the formation of non-physiological occlusion of the jaws in an experimental rat allows it to be used repeatedly under experimental conditions for a long time to comprehensively study pathological changes that occur both locally (directly in the periodontal tissues) and the general level (in the body ) in violation of physiological occlusion.

Information sources

1. Gross M.D., Matthews J.D. Normalization of occlusion / Gross M.D., Mathews J.D. // Occlusion in restorative dentistry. Churchill livingstone, 1982. - M .: Medicine, 1986.- 288 p.

2. Klineberg I., Jager R. Occlusion and clinical practice. - 2nd ed. - M.: MEDpress-inform, 2008 .-- 200 p.

3. Khvatova V.A. Occlusal tires - the current state of the problem // Maestro of Dentistry. - 2007. - No. 4. - S. 52-56.

4. https://ru.wikipedia.org/wiki/%D0%9A%D0%BB%D1%8F%D0%BF

5. http://www.krysota.ru/product_info.php?products_id=3514

Claims (1)

A stress-inducing device for the formation of non-physiological occlusion of the jaws of an experimental rat, including a fixing vest with two holes for the forepaws and one hole for the neck with a fastener on a contact tape, additionally containing a metal ball adapted to be placed in the mouth of the experimental rat in the sky between the dentition at the level of the posterior teeth and having a hole in the middle through which a round aramid thread 1 mm thick with two symmetrically races is freely passed Assumption silicone stoppers rigidly attached to a metal ring sewn into the collar fixing the vest.

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