JP2003210475A - Small bone extending device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform excellent bone extension of the skull such as the cranium and the jaw and in a bone extension experiment or the like using an animal in a medical research. <P>SOLUTION: Parts for gripping fixtures 3, 4 for the skull 1 and the jaw 2, provided with firm bone fixing means are screwed with a screw shaft 6, and an induction guide in an extending direction is installed at the grip part of the bone fixture. A rotational operating part 9 built in the tip of the screw shaft is rotated to allow parallel enlargement without the twisted rotation of a space between the fixtures, thus performing accurate bone extension treatment. The installation of the fixtures and screw shaft inside the skin of the face enables a patient to lead more a usual social life. The partial thickness of the jaw thinned after being obliged to odontectomy due to the decayed tooth or the like is recovered by vertical bone extension. The artificial root of tooth which cannot be implanted unless there is the thickness of the jaw is implanted in the jaw. The patient can thereby recover the original function of mastication without using a denture. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bone extension device used for fracture of a skull, extension of the length of the jawbone in jaw disorders, recovery of the partial thickness of the jawbone, and the like. . 2. Description of the Related Art As shown in FIG. 4, a conventional bone extension device fixes needle-like pins inserted from the skin and inserted into a bone to a support for extension, and sequentially places the pins together. The length of the bone is extended by increasing the interval by 1.0 mm on average per day. Another bone distraction device uses a small screw for bone fixation as shown in FIG. 5, screws the bone fixation device with a screw shaft, and enlarges the fixation device space by rotating the screw shaft. It is intended to extend the length. [0003] In a bone lengthening method used for fracture of a skull or extension of a jawbone in micromandibular disorders, a bone is artificially broken, and the distance between the ends of the bone is gradually reduced, for example, by 1%. 1.0 per day
This is a treatment method in which the length of the bone is lengthened by expanding the mm in several times. In the histological findings of the new bone formation process occurring in the extension gap, hematoma is formed first, and then the hematoma is organized and filled with fibrous connective tissue derived from bone marrow and periosteum to form young new bone and ossification Advances. In the clinical practice of medicine, a condition required for a bone distraction device is that the device has a strength against an excessive load applied to the device caused when the surrounding muscle is forcibly pulled by the extension operation, and that the device is accurately extended in a planned extension direction. It is important to have an extension guide that allows for parallel extension of the two. In addition, it is desirable that the bone distraction device be of a minimum size and weight so that the patient can live a normal social life as much as possible even during the bone distraction treatment. There is also a need to ensure that some parts of the world do not become infected by traffic. In addition, by restoring the thickness of the thin jawbone after being forced to extract teeth due to tooth decay,
Then, it becomes possible to bury artificial roots that cannot be buried without the thickness of the jaw bone into the jaw bone. However, in a conventional bone distraction device, FIG.
However, the device shown in FIG. 1 is an extension device in which a pin and a support punch appear on the outside of the skin on the face. In addition, it is not possible to easily perform a micro-adjustment in which a plurality of dissected bones are expanded by dividing about 1.0 mm per day into several times,
Further, there is a problem that infection is likely to occur due to the presence of the pins penetrating the skin on the face because of the communication with the outside world. Further, in the device as shown in FIG. 5, the bone fixing screw to be inserted into the bone is small, and the fixing tool and the screw shaft can be installed inside the face or the like. However, since the bone fixing screw is not sufficiently grasped, The device could not be firmly fixed to the bone, and the exact amount of extension could not be obtained. In addition, since there is no guide in the extension direction, there is a problem that the bone fixation pins are not parallel but rotated and enlarged during the bone extension operation. Therefore, the present invention solves the above-mentioned problems, and minimizes the size and weight of the bone extension device so that the patient can continue his usual social life even during the bone extension treatment.
In addition, due to its minimum size, the local thickness of the thin jawbone that has been forced to be extracted due to tooth decay or the like is restored by performing bone extension in the vertical direction, and then the thickness of the jawbone must be reduced. By embedding artificial implants that cannot be implanted into the jawbone, patients can restore their original masticatory function without using dentures. Furthermore, bone extension experiments can be performed on small animals not only in patients but also in animal experiments in medical research. In addition, by providing the guide in the extension direction to the gripping portion of the bone fastener, the distance between the disconnected epiphyses can be systematically enlarged in parallel, so that accurate bone extension treatment can be performed. In addition, an object of the present invention is to provide a bone distraction device that can minimize infection caused by installing the bone distraction device. According to the present invention, a portion for holding a fixture for a skull or a jawbone provided with strong bone fixing means is screwed together with a screw shaft, and further a guide for extension is provided. It is installed on the gripping part of the bone fixing device, and by rotating a rotary operation unit incorporated at the tip of the screw shaft, it is possible to perform parallel expansion without twisting the interval between the fixing devices, thereby enabling accurate bone lengthening treatment. Can be performed. Furthermore,
Since the fixture and screw shaft are installed inside the skin on the face, it is possible for the patient to carry out more usual social life, and because of its minimum size, it is necessary to extract teeth due to tooth decay etc. By restoring the thin jawbone thickness, it becomes possible to embed artificial tooth roots in the jawbone that would otherwise be impossible without the thickness of the jawbone, A small bone lengthening device characterized in that it can be adapted to bone lengthening experiments with small animals in animal experiments in medical research. FIG. 1 is a block diagram showing an embodiment of the present invention.
A description will be given with reference to FIGS. 1 is a skull and 2 is a jawbone composed of a mandible. In FIG. 1, the above-mentioned bone is used for the reason that the mandible 2 is short in the anteroposterior direction and to recover the thickness of the thin jawbone after the front teeth of the mandible have to be extracted due to tooth decay or the like. The case where extended treatment is performed is shown. Hereinafter, an embodiment in performing mandibular distraction will be described. Bone fixing devices 3 and 4 for fixing to mandible 2
Screw hole 10 of micro screw 5 which is a cylindrical bone fixing means
Is provided so that it can be fixed to the mandible 2.
A screw shaft 6 having a screw pitch of 0.4 mm is provided on the bone fixture 3.
Is provided with a female screw 12 into which the screw shaft 6 is screwed.
When the knob (rotation operating unit) 9 at the base end is rotated by rotating through the through hole 13 of the bone fixing tool 4, the bone fixing tool 3 moves in the enlargement direction, but the bone fixing tool 4 moves on the screw shaft. Do not change its position in the. When performing the extension operation, the bone fasteners 3 and 4 are provided with recesses so that the bone fasteners 3 and 4 can be enlarged in parallel, and penetrate through the rectangular extension guide 7 as the penetration portion 14 in the bone fastener 3. With the bone anchor 4
Then, the rectangular extension guide 7 and the bone fixing tool 4 are welded as the fixing portion 15. The bone fasteners 3, 4, the micro screw 5,
All parts of the present invention, such as the screw shaft 6, the rectangular extension guide 7 and the like, are made of a biomaterial alloy having excellent corrosion resistance (stainless steel, cobalt-chromium-molybdenum alloy, titanium alloy, etc.), and the bone anchor 3 , 4 thickness A 5.0 mm, length B
The length of the screw shaft 6 is 3.0 mm, the height C is 8.0 mm, the length D of the screw shaft 6 is 15.0 mm, and the diameter E thereof is 1.6 mm. These dimensions A, B, C, D, and E can be appropriately set according to the patient and the experimental animal. Next, the operation of the above configuration will be described. At the time of the operation, first, the upper mucous membrane in the oral cavity is incised.
0 and screw into the mandible to fix. Further, after the screw shaft 6 is passed through the through hole 13, the screw shaft 6 is screwed into the female screw 12. Then, inside the mucous membrane, an osteotomy is made between the two micro screws fixed to the bone, and the incised mucous membrane is closed. When the knob (rotation operating unit) 9 is turned after the bone extension device is attached in this manner, the bone fixing device 4 of the screw shaft 6 is idled while being held in contact with the knob 9, while the bone is fixed. Since the screw shaft 6 is screwed into the female screw 12 in the tool 3, the space between the two micro screws fixed to the bone is widened by rotating the screw shaft 6. By performing this rotation several times, for example, a bone extension amount of about 1.0 mm can be obtained per day. As described above, in the above embodiment, the mandible 2
The two micro screws 5 fixed to the bone are connected by a screw shaft 6 to widen the distance between the two bone fixing devices to extend the bone. However, the two micro screws 5 fixed to the bone and the screw shaft 6 are fixed. And so on are placed inside the oral mucosa, and only the knob 9 at the proximal end of the screw shaft 6 is placed inside the mucous membrane, so that the patient can enjoy ordinary social life even with the bone extension device attached. Can be operated and the bone distraction device can be minimized in size and weight. In addition, the extension guide 7 allows the micro screw 5 fixed to the bone to move in parallel, so that accurate bone extension treatment can be performed according to the treatment plan. Further, a screw shaft 6 is provided in the oral cavity.
Since only the base end is protruded, there is nothing on the skin of the appearance, and only one infected part can be present in the oral cavity, and the infection can be kept to a minimum. Further, the screw pitch of the screw shaft 6 is set to 0.25 m.
By appropriately setting m, 0.5 mm, 0.75 mm, and the like, accurate bone lengthening treatment can be performed with an easy operation. According to the present invention, a portion for gripping a skull or jaw bone fixing device having a strong bone fixing method is screwed together with a screw shaft, and further, a guide for extension is provided on the bone fixing device. It is installed on the grip part of the screw shaft, and by rotating the rotary operation part incorporated at the tip of the screw shaft, it is possible to perform parallel expansion without twisting the interval between the fixing tools, and to perform accurate bone extension treatment. Can be planned. Due to its minimum size, it is possible to restore the thickness of the jawbone, which is thin after the tooth extraction has to be performed not only for the entire jawbone but also for tooth decay, etc. This makes it possible to bury artificial tooth roots that cannot be implanted in the jaw bone, and furthermore, it is possible to perform bone lengthening experiments on small animals in animal experiments in medical research as well as in patients. [0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing an embodiment of the present invention. FIG. 2 is an exploded perspective view of a main part showing the embodiment of the present invention. FIG. 3 is a front view and a side view of a bone fastener according to an embodiment of the present invention. FIG. 4 is a perspective view showing a first conventional example. FIG. 5 is a perspective view showing a second conventional example. [Description of Signs] 1 skull 2 jawbone (mandible) 3 4 bone fixation device 5 micro screw 6 screw shaft 7 square extension guide 8 screw shaft fixation device 9 knob (rotation operation unit) 10 screw hole 11 micro screw fixation device 12 female screw 13 through hole 14 through part 15 fixing part

Claims (1)

Claims: 1. A portion for gripping a bone fixing device provided with a bone fixing means is screwed together with a screw shaft provided with an operation portion at a tip thereof.
And it can be expanded in parallel without twisting the spacing of these fixtures, and from its size, it is possible to recover the part of the jaw bone that became thin and thin after tooth extraction with tooth decay,
A small bone lengthening device characterized by being adaptable to small animals and the like.