RU2445711C2 - Method for simulating osteoarthrosis in temporomandibular joint - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention may be used for simulating and studying osteoarthrosis (OA) in a temporomandibular joint (TMJ). For this purpose, an experimental animal under general anaesthesia is laid on its side on a horizontal surface. With the use of a loop-ended ligature an upper jaw is fixed to a hook fastened on the horizontal surface. The ligature loop thereby envelope animal's upper incisor teeth. Another loop ligature is used to take a lower jaw down. The ligature loop thereby envelope animal's lower incisor teeth. The other ligature end is loaded 200 g that is equal to force 2N. The loaded ligature fastened to the lower incisor teeth and freely dropping from the horizontal surface enables the maximum mutual divergence of the animal's jaws and the loaded TBJ. As specified above, the animal's TBJ is loaded for 3 h a day for 5 days running.

EFFECT: method is simple, easily reproducible; it does not require a complex oral equipment at preset force 2N; it is applicable in any animal and enabled a joint tissue injury with no traumatic factor applied.

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Description

The invention relates to experimental medicine, in particular to dentistry, and can be used to model and study osteoarthrosis (OA) of the temporomandibular joint (TMJ).

In the study of scientific literature, we found various methods for modeling OA TMJ. In some models, surgical intervention was performed on the intraarticular disk, the condyle of the lower jaw, and the articular tubercle to obtain TMJ OA. For example, partial resection of the disc or TMJ discectomy [Chang J., Ma X., Wu D., Jiao Y. Study on the characteristics of apoptosis in the condyles of osteoarthritic temporomandibular joints / Hua Xi Kou Qiang Yi Xue Za Zhi, 2004; 22 (5): 353-6] [Meng J., Ma X., Li Z., Wu D. Aquaporin-1 and aquaporin-3 expressions in the temporomandibular joint condylar cartilage after an experimentally induced osteoarthritis / Chin Med J 2007; 120 (24): 2191-2194], disk perforation [Ishimari J., Goss A. A model for osteoarthritis of the temporomandibular joint / J Oral Maxillofac Surg 1992; 50: 1191-1195], perforation of the disc and surface of the head of the lower jaw [Axelsson S., Holmlung A., Hyerpe A. An experimental model of osteoarthrosis if the temporomandibular joint of the rabbit / Acta Odontol Scand 1992; 50: 273-280], anterior displacement of the disc after an osteotomy of the base of the zygomatic process and articular tubercle and forward movement of the bone fragment, followed by fixation in a new position with a mini plate [Tominaga K., Hirashima S., Fukuda J. An experimental model of osteoarthrosis of the temporomandibular joint in monkeys / J Oral Maxillofac Surg 2002; 40: 232-237]. However, surgical operations cause not only mechanical changes in the TMJ, but also artificial surgical damage to joint structures. In this regard, the described OA models cannot be regarded as a real mechanical load on the TMJ in comparison with the real load that causes damage to joint tissues without a traumatic factor. At the same time, performing surgical procedures on TMJ is technically difficult and does not exclude the development of postoperative complications.

Also proposed are models of OA TMJ by introducing various substances into the joint cavity. For example, a papain solution [Yang F., Shi Z. A study on papain-induced osteoarthritis in rabbit temporomandibular joint / Hua Xi Kou Qiang Yi Xue Za Zhi 2002; 20 (5): 330-2], collagenase solution [Bian C., Li D. Animal experimental study of intra-articular injection of S-methylisothiourea for treatment of temporomandibular joint osteoarthrosis // Hua Xi Kou Qiang Yi Xue Za Zhi 2007; 25 (3): 213-5], matrix metalloproteinase-1 [Xinmin Y, Jian H. Treatment of temporomandibular joint osteoarthritis with viscosupplementation and arthrocentesis on rabbit model / Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005; 100 (3): 35-8]. The introduction into the joint cavity of any chemical substance, first of all, causes a inflammatory response in the form of synovitis, which, subsequently, can cause secondary degenerative changes in the tissues of the joint. This reproduction of OA can explain changes in cartilage and bone in the chronic course of arthritis.

The closest analogue (prototype) of the proposed method is the simulation of OA TMJ, which is as follows [Fujisawa T., Kuboki T., Kasai T. et al. A repetitive, steady mouth opening induced an osteoarthritis-like lesion in the rabbit temporomandibular joint / J Dent Res 2003; 82 (9): 731-735]. A device was introduced into the oral cavity of the experimental animal for maximal dilution of the jaws with a constant expansion force of 2 N for 3 hours a day for 5 days daily. The force in 2H was calculated by a preliminary experiment by the authors of the method. This model demonstrates that an increased joint load without surgery can cause OA-like pathological changes naturally.

However, this method has several disadvantages:

- individual manufacture of an intraoral device for an experimental animal, which should play the role of an expander with a given force of 2N,

- the manufacture of such a device is associated with technical difficulties and high cost.

Because of this, this method is difficult to reproduce.

The technical result is an increase in reproducibility and a simplification of the method through the use of ligatures to hold the jaws of the animal in the position of maximum breeding and use of cargo weighing 200 g (improving ease of use on any experimental animal).

In comparison with the analogue, the proposed method has the following advantages:

- simple, does not require the implementation of a technically complex intraoral device with a given voltage of 2N,

- perform on any animal, there is no need to take into account the structural features of the dentition, teeth, etc.,

- easily reproducible due to the simplicity of the devices used,

- requires less material costs through the use of cheap materials (ligature, hook, cargo weighing 200 g).

This technical result is achieved by the fact that the experimental animal in a state of anesthesia in the supine position is laid on a horizontal surface. Using a ligature with a loop at the end, the upper jaw is fixed to the hook, which is fixedly mounted on a horizontal surface. The ligature loop at the same time covers the upper front incisors of the animal. Another ligature with a loop take the lower jaw down. The ligature loop covers the lower incisors of the animal. At the other end of this ligature, a weight of 200 g is fixed (which corresponds to a force of 2H). A ligature with a load, mounted on the lower incisors and freely hanging from a horizontal surface, allows you to maximize the jaws of the animal relative to each other and create a load on the TMJ. The indicated load on the TMJ of the animal is created 3 hours a day for 5 days daily.

Example. Xylazine and zoletil-100 were administered intramuscularly to the experimental animal, the rabbit, on each experimental day. The rabbit is lying on its side and laid on a horizontal wooden surface. With a ligature with a loop at the end, the upper jaw is fixed to a metal hook, which is fixedly mounted on a horizontal wooden surface. In this case, the ligature loop covers the upper incisors of the rabbit. Another ligature with a loop at one end is fixed on the lower incisors of the rabbit and the other end with a weight of 200 g is lowered down, hangs freely relative to the horizontal surface and creates the maximum dilution of the jaws of the animal for 3 hours. This experimental protocol was repeated for 5 days daily.

The rabbit was withdrawn from the experiment on day 7. In the rabbit, layer-by-layer tissues were prepared on the lateral parts of the head up to the TMJ. Joint tissues (head of the lower jaw, articular disc) were fixed in 10% neutral formalin, decalcified, immersed in paraffin for histological examination. Sagittal tissue sections stained with hemotoxylin and eosin were studied under an electron microscope.

The results of a histological examination showed compaction of the articular cartilage, proliferation of chondrocytes in the subchondral layer of the bone. Islands of hypertrophied chondrocytes with tissue mineralization. Proteoglycan depletion. Matrix deposition along the front edge of the articular surface.

Thus, on the 7th day of the experiment, there are characteristic morphological signs of a simulated disease - OA.

Claims (1)

A method for modeling osteoarthritis of the temporomandibular joint (TMJ), which consists in laying an experimental animal in a lying position on its side on a horizontal surface, using a ligature with a loop at the end, the upper jaw is fixed to a hook that is fixedly mounted on a horizontal surface at the same time, the upper front incisors of the animal are covered with a loop of the ligature, the lower jaw is taken down with another ligature with the loop, the lower incisors of the animal are covered with the ligature loop, on the other end of the ligature is fixed a weight of 200 g, maximum jaw animal bred with respect to each other and create a strain on the TMJ for 3 hours a day for 5 days on a daily basis.