Construction method of SD (Sprague Dawley) rat animal model for assisting bone expansion of maxillary bone by using planting nails with holes

Abstract

The invention discloses a construction method of an SD (Sprague Dawley) rat animal model for assisting maxillary bone bony expansion by using planting nails with holes, and relates to the field of experimental zoology, and the construction method comprises the following steps: (1) anesthetizing a rat and fixing the rat; (2) implanting planting nails with holes into the maxillary bone at 1 mm mucous membranes before first molar teeth of the maxillary on the two sides of the rat, and enabling the holes in the planting nails on the two sides to be opposite to each other; (3) adjusting the expansion force of the expansion spring to 100g, and clamping the expansion spring into the holes of the planting nails on the two sides for expansion; and (4) taking down the expansion spring on the fifth day, re-adjusting the expansion force of the expansion spring to 100g, clamping the expansion spring into the holes of the planting nails on the two sides for expansion, taking down the expansion spring and the planting nails on the tenth day, and finishing expansion, so as to obtain the SD rat animal model of maxilla bony expansion. The animal model constructed by the invention not only can expand the middle palate seam, but also can expand the front palate seam, and the model can play an important role in the aspects of researching the osteogenesis mechanism and influence factors of the middle palate seam during the bony expansion period of the maxillary bone, exploring the treatment means of the bony expansion recurrence of the maxillary bone and the like.

Description

Technical Field

[0001] The invention relates to the field of experimental animal science, and in particular to a method for constructing an SD rat animal model for maxillary bone expansion assisted by implant screws with holes. Background Art

[0002] Maxillary transverse development deficiency (MTD) often leads to problems such as crowded dentition, maxillary and mandibular imbalance, unilateral or bilateral posterior crossbite, etc. In clinical practice, orthodontists treat by expanding the maxillary alveolar bone base and dental arch laterally to open the midpalatal suture. At present, the main methods of arch expansion are tooth-supported expanders and bone-supported expanders. Among them, bone-supported expanders represented by micro-screw-assisted rapid maxillary expander (MSE) can achieve better arch expansion effects, expand the age range of non-surgical maxillary arch expansion treatment, and also reduce the side effects of tooth-supported arch expansion on teeth. In order to better study the bone formation mechanism, influencing factors and recurrence of maxillary bone expansion during maxillary bone expansion, it is necessary to construct an animal model for in vivo research. At present, most researchers study the osteogenesis of the midpalatal suture by performing tooth-supported arch expansion on rats, but due to the narrow oral cavity of rats, no researchers have designed a maxillary bone expansion model suitable for rats. Summary of the invention

[0003] In view of the problems existing in the above-mentioned prior art, the present invention designs a maxillary bony expansion device assisted by a perforated implant screw, and provides a method for constructing a SD rat animal model of maxillary bony expansion using the bony expander.

[0004] To achieve the above object, the present invention provides a method for constructing a SD rat animal model of maxillary bone expansion, comprising the following steps:

[0005] (1) Anesthetize the rat and fix it;

[0006] (2) implanting a perforated implant screw into the maxillary bone 1 mm in front of the first maxillary molars on both sides of the rat, so that the holes on the implant screws on both sides face each other;

[0007] (3) Adjust the expansion force of the expansion spring to 100 g and insert it into the holes of the implant pins on both sides to expand the arch;

[0008] (4) On the 5th day, the expansion spring was removed, and the expansion force was readjusted to 100 g. The expansion spring was inserted into the holes of the implant screws on both sides to perform expansion. On the 10th day, the expansion spring and the implant screws were removed to terminate the expansion, thereby obtaining a SD rat animal model of maxillary bone expansion.

[0009] Preferably, the implant screw with a hole comprises a threaded area 1; a base area 2, which is a regular hexagonal prism; and a through hole 3, which is located on the side of the regular hexagonal prism in the base area and opposite to it.

[0010] Preferably, the implant nail with holes is a titanium alloy (TC4ELI) for surgical implants that meets the 13810 standard.

[0011] Preferably, the perforated implant screw is root-shaped, with a total length of 5.4 mm for the main body, a length of 3.8 mm for the threaded area 1, and a length of 1.6 mm for the base area 2.

[0012] Preferably, the diameter of the spiral region 1 is 0.8 mm, the diameter of the through hole 3 is 0.5 mm, and the side length of the regular hexagonal prism is 1 mm.

[0013] Preferably, the expansion spring is made of 0.5 mm stainless steel wire, the middle part of which is bent into a ring curve 4 with a diameter of 2 mm, and the long arms 5 on both sides are bent in opposite directions to form a symmetrical structure with a length of 5 mm. The tail ends of the long arms 5 on both sides are bent outward to form a hook-shaped structure, and the hook can be inserted into the through hole 3 of the implant nail to fix the expansion spring on the implant nail to achieve expansion.

[0014] Preferably, step (2) also includes a step of inspecting the insertion position of the implant screw: using tweezers to check whether the implant screw is loose to determine whether it is implanted in the maxillary bone rather than the nasal cavity.

[0015] Preferably, the expansion force of the expansion spring is measured using a push-pull dynamometer, and is adjusted by the dental arch distance measured between the mesio-palatal cusp of the first molar and the dental dynamometer, wherein the push-pull dynamometer has been improved and a hole-carrying implant screw is fixed on the measuring head; during measurement, a hole-carrying implant screw is nailed into a wooden board, and the spring is inserted into the wooden board implant screw and the push-pull dynamometer implant screw to measure the force value so as to obtain a more accurate expansion force value.

[0016] In a preferred embodiment of the present invention, the present invention further provides a device for assisting maxillary bone expansion with a perforated implant screw, which comprises a perforated implant screw and an expansion spring, wherein the perforated implant screw comprises a threaded area 1; a base area 2, which is a regular hexagonal prism; and a through hole 3, which is located on the side of the regular hexagonal prism in the base area and opposite to it;

[0017] The expansion spring is made of 0.5 mm stainless steel wire, the middle of which is bent into a ring curve 4 with a diameter of 2 mm, and the long arms 5 on both sides are bent towards opposite directions to form a symmetrical structure with a length of 5 mm. The tail ends of the long arms 5 on both sides are bent outwards to form a hook-shaped structure;

[0018] The hook can be inserted into the implant nail through hole 3, and the expansion spring is fixed on the implant nail to achieve expansion.

[0019] Preferably, the implant nail with holes is a titanium alloy (TC4ELI) for surgical implants that meets the 13810 standard.

[0020] Preferably, the perforated implant screw is root-shaped, with a total length of 5.4 mm for the main body, a length of 3.8 mm for the threaded area 1, and a length of 1.6 mm for the base area 2.

[0021] Preferably, the diameter of the spiral region 1 is 0.8 mm, the diameter of the through hole 3 is 0.5 mm, and the side length of the regular hexagonal prism is 1 mm.

[0022] Preferably, the spiral region 1 of the implant screw with holes is implanted into the bone, and the base region 2 remains in the mouth.

[0023] The present invention provides a method for constructing an animal model of SD rats for maxillary bone expansion assisted by a perforated implant screw. The method uses a self-made bone expansion device to expand the maxilla of the rats. Experimental results show that within 10 days of expansion, the expansion device with a force value of 100 g significantly expands the mid-palatal suture. The present invention has the following technical effects:

[0024] 1. The first maxillary bone expansion model of SD rats was created to study the expansion mechanism, influencing factors and recurrence and maintenance of maxillary bone expanders (MSE) in clinical practice;

[0025] 2. A special implant nail with holes is designed to fix the expansion spring through the small holes, making it difficult to fall off. The expansion spring is easy to put on and take off, and the spring force value can be adjusted according to needs to simulate the intermittent force of clinical orthodontics;

[0026] 3. The implant is lower than the occlusal plane, which has little effect on chewing and is conducive to simulating clinical orthodontic conditions. It is inserted and fixed with the expansion spring to construct an animal model of bony expansion, and ensures that it does not affect chewing and is not easy to fall off, simulating the intraoral conditions of expansion more realistically.

[0027] 4. As the rat's mouth is small, it is not possible to implant an implant between the posterior teeth for maxillary expansion. Therefore, the implant was placed 1 mm in front of the maxillary first molar so that it could expand both the mid-palatal suture and the anterior palatal suture. This model can play an important role in studying the osteogenesis mechanism and influencing factors of the mid-palatal suture during maxillary bony expansion and exploring the treatment methods for the recurrence of maxillary bony expansion.

[0028] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 1 is a schematic diagram of the structure of the implant nail of the present invention; wherein 1 is the threaded area, 2 is the base area, and 3 is the through hole.

[0030] Figure 2 It is a schematic diagram of the structure of the expansion spring of the present invention; wherein 1 is a ring curve, 4 and 5 are long arms.

[0031] Figure 3 This is a schematic diagram of the intraoral state of SD rats after implantation, placement of the arch expansion device, and occlusion.

[0032] Figure 4 Figure 3 shows the changes in rat body weight after placement of the arch expansion device.

[0033] Figure 5 These are the modeling results and Micro-CT three-dimensional reconstruction images of the force-added group and the sham operation group after 10 days of arch expansion using the arch expansion device of the present invention.

[0034] Figure 6 CT images of the force-added group and the sham operation group after 10 days of arch expansion using the arch expansion device of the present invention. DETAILED DESCRIPTION

[0035] The following describes several preferred embodiments of the present invention with reference to the drawings in the specification, so that the technical content is clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0036] In the drawings, components with the same structure are indicated by the same numerical reference numerals, and components with similar structures or functions are indicated by similar numerical reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of the components is appropriately exaggerated in some places in the drawings.

[0037] Example 1

[0038] A method for constructing a SD rat animal model of maxillary bone expansion assisted by a perforated implant screw, the method comprising the following steps:

[0039] (1) Fix the rat after gas anesthesia or injection anesthesia to fully expose the rat's oral cavity;

[0040] (2) Use a dry cotton ball to clean the upper palate, dip it in iodine or alcohol for disinfection, place a vernier caliper between the mesio-palatal cusps of the first molars on both sides to measure the dental arch distance and record the data 1;

[0041] (3) Use a skin marker to mark the mucosa approximately 1 mm in front of the maxillary first molars on both sides;

[0042] (4) Use a scalpel to make a 1 mm incision at the marked position, use the handle to implant the implant screw with holes into the maxillary bone from the incision, and make the holes on the implant screws on both sides face each other. Use tweezers to check whether the implant screw is loose to determine whether it is implanted in the maxillary bone rather than the nasal cavity. Place a vernier caliper between the implant screws on both sides to measure the distance and record the data 2;

[0043] (5) Bend a 0.5 mm diameter stainless steel wire into an expansion spring. Bend a 100 g expansion spring according to Data 2 and a dental dynamometer, insert it into the holes of the implant pins on both sides, disinfect the upper palate with iodine again, and wait for the patient to wake up.

[0044] (6) On the fifth day after the force application, the spring was removed, the distance between the nails was measured, and the force value was readjusted to 100 g based on the measured data. On the tenth day, the expansion device was removed and the expansion was terminated.

[0045] Among them, the implant nail with hole ( Figure 1 ) is made of titanium alloy for surgical implants that meets the 13810 standard, including an intrabone threaded area 1, an intraoral abutment area 2, and a through hole 3 with a diameter of 0.5 mm on one side of the abutment area and the opposite side; the implant screw body is root-shaped, with a total length of 5.4 mm, an intrabone threaded area 1 of 3.8 mm, an intraoral abutment area 2 of 1.6 mm, and an intrabone spiral area 1 of 0.8 mm in diameter. The abutment area is a regular hexagonal prism with a side length of 1 mm. The regular hexagonal abutment matches the hexagonal implant screw handle, which is convenient for implantation and rotational force. So that the expansion spring can be inserted and fixed.

[0046] The expansion spring device ( Figure 2 ) is made of 0.5mm stainless steel wire, the middle of which is bent into a ring curve 4 with a diameter of 2mm, and the long arms 5 on both sides are bent towards opposite directions to form a symmetrical structure with a length of 5mm; the tail ends of the long arms 5 on both sides are bent outward to form a hook-shaped structure, which can be inserted into the through hole 3 of the implant nail, and the expansion spring is fixed on the implant nail. When the expansion spring device is compressed to 100g using a dental dynamometer, the distance between the tail ends of the long arms on both sides needs to be exactly data 2. Figure 3 The intraoral schematic diagram of the SD rat arch expansion model during construction shows the implantation of the implant screw, placement of the arch expansion device, and occlusion. The occlusion diagram indicates that the implant screw has no significant effect on the occlusal relationship.

[0047] Example 2

[0048] The body weight of the constructed SD rat animal model of maxillary bone expansion assisted by implant screws with holes was measured, including the following steps:

[0049] (1) The SD rats were weighed and the data were recorded on day 0, 3, 5, 7, and 10 of arch expansion.

[0050] (2) Use Prism 9 software to plot the obtained weight data into a line graph.

[0051] like Figure 4 As shown in the figure, the weight of SD rats increased during the 10 days of arch expansion, indicating that the model has little effect on the chewing function of rats. The weight gain on days 0-3 and 5-7 was smaller than that on days 3-5 and 7-10, which may be due to the fact that SD rats were in the recovery period of surgery.

[0052] Example 3

[0053] Micro-CT scanning was performed on the constructed SD rat animal model of maxillary bone expansion assisted by implant screws with holes, including the following steps:

[0054] (1) The maxillae of euthanized SD rats were dissected and fixed with 4% paraformaldehyde for 24 hours.

[0055] (2) Micro-CT scanning was performed on the fixed maxillary specimens of SD rats using a Skysan 1276 X-ray microtomography system. The voxel size was 8.5 μm, the X-ray tube voltage was 70 kV, and the current was 200 μA.

[0056] (3) Use NRecon software to perform three-dimensional reconstruction, and use DataViewer and CTvox to observe the reconstructed images.

[0057] like Figure 5 As shown in the figure, the implant was located in front of the first molar of the rat. Compared with the sham operation group, the gap between the maxillary incisors of the rats after 10 days of arch expansion was significantly increased. Figure 6 As shown, compared with the sham operation group, the anterior palatal suture (red) and the mid-palatal suture (yellow) of the rats that underwent 10-day expansion were significantly enlarged, and serrated protrusions were visible in the gap.

[0058] The preferred specific embodiments of the present invention are described in detail above. It should be understood that ordinary technicians in the field can make many modifications and changes based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by technicians in the technical field based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for constructing a SD rat animal model of maxillary bone expansion, comprising the following steps: (1) Anesthetize the rat and fix it; (2) implanting a perforated implant screw into the maxillary bone 1 mm in front of the first maxillary molars on both sides of the rat, so that the holes on the implant screws on both sides face each other; (3) Adjust the expansion force of the expansion spring to 100 g and insert it into the holes of the implant pins on both sides to expand the arch; (4) On the 5th day, the expansion spring was removed, and the expansion force was readjusted to 100 g. The expansion spring was inserted into the holes of the implant screws on both sides to perform expansion. On the 10th day, the expansion spring and the implant screws were removed to terminate the expansion, thereby obtaining a SD rat animal model of maxillary bone expansion.

2. The method for constructing the SD rat animal model of maxillary bone expansion according to claim 1, characterized in that: The step (2) also includes a step of checking the insertion position of the implant screw: using tweezers to check whether the implant screw is loose to determine whether it is implanted in the maxillary bone rather than the nasal cavity.

3. The method for constructing the SD rat animal model of maxillary bone expansion according to claim 1, characterized in that: The implant nail with holes comprises: Threaded area (1); A base region (2), the base region is a regular hexagonal prism; and The through hole (3) is located on the side of the regular hexagonal prism in the base area and opposite to it.

4. The method for constructing the SD rat animal model of maxillary bone expansion according to claim 3, characterized in that: The perforated implant nail is root-shaped, with a total length of 5.4 mm for the main body, a length of 3.8 mm for the threaded area (1), and a length of 1.6 mm for the base area (2); optionally, the diameter of the spiral area (1) is 0.8 mm, the diameter of the through hole (3) is 0.5 mm, and the side length of the regular hexagonal prism is 1 mm.

5. The method for constructing the SD rat animal model of maxillary bone expansion according to any one of claims 1 to 4, characterized in that: The implant nail with holes is made of titanium alloy for surgical implants that meets the 13810 standard.

6. The method for constructing the SD rat animal model of maxillary bone expansion according to claim 1, characterized in that: The expansion spring is made of 0.5 mm stainless steel wire, the middle of which is bent into a ring curve (4) with a diameter of 2 mm, and the long arms (5) on both sides are bent in opposite directions to form a symmetrical structure with a length of 5 mm. The tail ends of the long arms (5) on both sides are bent outward to form a hook-shaped structure, and the hook can be inserted into the implant nail through hole (3) to fix the expansion spring on the implant nail to achieve expansion.

7. The method for constructing the SD rat animal model of maxillary bone expansion according to claim 1, characterized in that: The expansion force of the expansion spring is measured using a push-pull dynamometer, and is adjusted by the dental arch distance measured between the mesio-palatal cusp of the first molar and the dental dynamometer; preferably, the push-pull dynamometer has been improved, and a hole-carrying implant screw is fixed on the measuring head; during measurement, a hole-carrying implant screw is nailed into a wooden board, and the spring is inserted into the wooden board implant screw and the push-pull dynamometer implant screw, and the force value is measured so as to obtain a more accurate expansion force value.

8. A device for assisting maxillary bone expansion with a perforated implant screw, comprising a perforated implant screw and an expansion spring, wherein the perforated implant screw comprises: Threaded area (1); Abutment area (2), the abutment area is a regular hexagonal prism; and A through hole (3) is located on the side of the regular hexagonal prism in the base area and opposite to it; The expansion spring is made of 0.5 mm stainless steel wire, the middle of which is bent into a ring-shaped curve (4) with a diameter of 2 mm, and the long arms (5) on both sides are bent in opposite directions to form a symmetrical structure with a length of 5 mm, and the tail ends of the long arms (5) on both sides are bent outward to form a hook-shaped structure; The hook can be inserted into the implant nail through hole (3), and the arch expansion spring is fixed on the implant nail to achieve arch expansion.

9. The maxillary bone expansion device assisted by a perforated implant screw according to claim 8, characterized in that: The perforated implant nail is root-shaped, with a total length of 5.4 mm for the main body, a length of 3.8 mm for the threaded area (1), and a length of 1.6 mm for the base area (2); optionally, the diameter of the spiral area (1) is 0.8 mm, the diameter of the through hole (3) is 0.5 mm, and the side length of the regular hexagonal prism is 1 mm.

10. The maxillary bone expansion device assisted by a perforated implant screw according to claim 8 or 9, characterized in that: The implant nail with holes is made of titanium alloy for surgical implants that meets the 13810 standard.

Images