RU2302218C2 - Method and bone distraction device for increasing (screw distraction) bone tissue growth - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: method involves detaching flap. Osteotomy and compact osteotomy is carried out. Bone bed is built. Intraosseous implant is introduced into the bone bed. When reaching bed bottom, the implant rotation is continued at the same place so that bone portion separated by osteotomy moves along the implant thread in opposite direction when compared to implant introduction direction.

EFFECT: enhanced effectiveness of surgical intervention in inaccessible areas; accelerated treatment course.

9 cl, 2 dwg

Description

The invention relates to medicine, specifically to dentistry, maxillofacial surgery, traumatology, and can be used to increase bone tissue in operations of intraosseous implantation, restoration of defects of the bones of the maxillofacial skeleton, etc.

State of the art

To increase the volume of bone tissue in maxillofacial surgery and traumatology, various designs of distraction devices are used.

During operations in the oral cavity, methods of directed bone tissue regeneration, autologous bone graft transplantation, and alveolar bone splitting according to the “green branch” type (Rendo B., Rendo R., Saba S., etc.) are used. Controlled bone growth of the alveolar bone (fracture of the type “ green twig ") in combination with implants. // New in dentistry. - 1997. - No. 2. - P.23-34.)

However, these methods are mainly used to increase the thickness of the alveolar ridge and are not effective with insufficient height of the alveolar ridge of the jaw, and, as you know, a large group of contraindications for intraosseous implantation are contraindications associated with the lack of vertical size of the alveolar part of the jaw.

If the height of the alveolar process on the upper jaw is insufficient, various methods of lifting the maxillary sinus fundus (classic, “soft” sinus lift, etc.) are used. A disadvantage of the maxillary sinus fundus method is that this method cannot increase bone lost due to atrophy. Sinuslifting allows you to increase the alveolar process due to the shift, "oppression" of the adjacent anatomical region - the maxillary sinus, which is associated with the risk of complications (especially with classical sinuslifting) and does not allow you to restore the interalveolar distance necessary for prosthetics.

Known methods in which hardware distraction is performed. There are intraosseous distractors - implants and "external fixation" distraction devices. In most distraction apparatuses, the active element is a spreading screw (threaded rod), which extends one support of the apparatus and the segment of bone tissue in which it is fixed from another support of the apparatus and, accordingly, another segment of bone. The spreading screw in the distraction apparatus does not directly transmit mechanical impact to the bone. The load on the bone is transmitted through the supports and spokes of the apparatus.

The disadvantage of intraosseous distractors - implants - is the design complexity, insufficient fixation force in the bone tissue compared to a standard implant. The disadvantage of using “external fixation” distraction apparatuses (external fixation) is cumbersomeness, difficulty in installation, long treatment periods, the need for additional surgical intervention to remove the apparatus; in a limited space of the oral cavity it is not always possible to install a distraction apparatus, in addition, it can interfere with the closure of the dentition and the chewing process, so the use of distraction apparatus in dentistry - implantology is of a single nature.

Closest to the proposed is a method of increasing the volume of the alveolar bone using an intraosseous implant (patent for invention RU No. 2202980, priority 04/08/2002), by which an increase in the height and thickness of the alveolar bone during intraosseous implantation is achieved. In this method, bone tissue distraction is performed by rotating a threaded implant in a bone that is previously dissected.

The aim of the invention is a controlled increase in bone volume, simplification and improvement of surgical intervention, improvement of functional results, acceleration of treatment time for operations to increase bone tissue in the maxillofacial region and intraosseous implantation.

SUMMARY OF THE INVENTION

The difference of the claimed method is that the implant (or screw) moves apart the dissected parts of the bone from each other (like the spreading screw of a distraction apparatus), but the mechanical effect of the rotation is transmitted directly to the bone tissue, as a result of which it is cut off (completely or partially) from the main mass a bone site (fragment) moves when the implant rotates along a thread (helical spiral), i.e. screw distraction occurs.

The technical result is achieved due to the fact that the increase in the bone tissue of the alveolar bone or other bones of the skeleton is carried out by osteotomy and / or compactosteotomy of the enlarged area of the bone tissue and creating a controlled helical distraction - pushing (stretching) the bone tissue along the dissection line, by introducing a threaded implant screws into the formed bed, and the osteotomy is made so that the bottom of the bone bed for the introduction of the implant is located in the bulk bones (fixed part), and the other part - in the elevated area (fragment); bone tissue distraction (separation of fragments) is achieved due to the fact that the rotation of the implant or screw in place, after it has reached the bottom of its bed, leads to a longitudinal movement of the bone along the thread of the implant in the opposite direction of the implant input, and also creates tension stretching (distraction) in the bone tissue, which concentrates along the line of bone dissection (osteotomy or compactosteotomy) and moves apart dissected bone tissue from each other.

Distraction stress can lead to an additional increase in bone tissue in the postoperative period without rotation of the implant. When the bone section (fragment) is completely cut off, it is usually fixed (with a spoke, screw, bone nail, wire, other implant) to keep it from turning when the implant rotates.

To implement the method, a screw dental implant or screw (bone screw) is used, having a thread in increments of 0.6 mm to 2.0 mm and a thread profile height of 0.2 mm to 1.5 mm. The implant or screw may contain the cervical part (or neck) with or without thread.

The side part can be polished or sandblasted. As an embodiment, the thread can be persistent, metric, conical, special, as well as multi-starting. The thread profile can be triangular, trapezoidal, special. The thread profile may be blunt or made with a radius. The end of the implant is usually blunt. The implant or its cervical part (neck) can be cylindrical or conical in shape, two-stage and one-stage, collapsible and non-collapsible can be used. For screw distraction in other parts of the skeleton, various screws, screws or screw implants can be used. The implant (screw) perform several sizes of threads for various clinical situations. The pitch and height of the thread profile is selected depending on the bone density so that the thread does not break in the raised portion of the bone, and in the area of the bottom of the bone bed is compressed by the threads of the implant. For this, the implant (screw) is usually performed with lowering the height of the thread profile to its end, or perform the end without thread.

The method of helical distraction (SVD) is as follows. During operations in the oral cavity on the alveolar ridge, an incision and exfoliation of the mucosal-periosteal flap is performed. If necessary, detachment is performed by cutting a trapezoidal, straight flap or oncoming triangles. Special drills and cutters create a bone bed (bone channel), while the diameter of the formed channel is less than the diameter of the threaded part of the implant by the height of its thread profile (thread diameter minus the diameter of the implant rod (screw)) for introducing the implant with self-cutting. The length (depth) of the formed bed is less than the length of the inserted implant, usually by the amount of subsequent increase in bone tissue. An osteotomy is performed in such a way that the created bone bed for implant insertion is located with the end part (bottom) in the bulk of the bone (fixed part), and the other part of the bed in the elevated area (fragment). Dissection of bone tissue can be carried out at different angles to the axis of implant placement. At the same time, additional cuts or dissections of bone tissue can be made on adjacent to the raised sections of the alveolar process to prevent the formation of a step. The implant or screw is inserted by screwing it into the created bone bed. After the implant abuts against the bottom of the bone channel, the rotation continues in place, creating compression stress of the bone tissue sections located in its thread (between the threaded protrusions) in the area of the bed bottom, and distraction stress along the dissection line, while the bone section is cut off tissue moves (rises) along the thread of the implant in the direction opposite to the (opposite) direction of insertion of the implant (figure 1).

One revolution of the implant (screw) leads to the distraction of bone tissue by the size of the thread pitch. Knowing the thread pitch of the implant (screw, screw), it is possible to carry out controlled distraction of bone tissue. In this case, the implant, immersed in the bone tissue, “builds up” the necessary amount of bone tissue. Thus, an increase in bone volume is achieved by increasing your own bone mass, compensating for atrophied bone tissue, which allows you to restore the interalveolar distance.

The introduction of the implant (screw) and bone distraction is carried out gradually, in several stages within 1-9 weeks, or, if necessary, a small increase, simultaneously, screwing the implant immediately to the entire length of the bone tissue. The threaded part of the implant protruding into the oral cavity can be closed by a screw-on part (sleeve). After simultaneous extension of bone tissue segments, osteoplastic materials can be introduced into the distraction slit.

Distraction can be carried out by two or more screws (implants), while rotation can be performed alternately, one implant performs distraction, and the other fixation and / or compression. The rate of distraction of 0.6-1.0 mm per visit (per day). The average period of formation of bone regenerate is 2-15 days for 3 mm elongation. After the implant is inserted, a plug is installed, sutures are applied. With a slight increase in bone, the waiting period for prosthetics is usually 3 weeks. If necessary, the terms may be increased.

This method was used in the treatment of 16 patients. Good functional results are obtained.

Clinical example

A 35-year-old patient had an included maxillary defect in the region of 15, 14, 13, 12, 11. Bone tissue atrophy caused by tooth loss led to a decrease in the thickness and vertical size of the alveolar process. To restore the defect, the patient is shown an increase in the height and thickness of the alveolar process of the specified area. Under the infiltration anesthesia, an incision was made along the ridge of the alveolar ridge, the mucosal-periosteal flap was exfoliated, and a guide channel was formed for the introduction of the implant. Thin burs and a chisel made a dissection of the cortical and partially spongy layers of the alveolar process along the border of the put forward site. A longitudinal osteotomy was also performed along the crest of the alveolar ridge in the region of the absent 13, 12, 11, to simultaneously increase the thickness of the indicated area. In area 12, an implant with a diameter of 3.5 mm and a length of 11 mm was inserted, having a thread with a pitch of 0.75 mm. The introduction was carried out by gradual rotation of the implant in several visits, as a result of which there was an extension of bone tissue by 3 mm. Five weeks after the formation of the bone regenerate, two implants were installed in the area of 15 and 11 teeth. After another 3 weeks, prosthetics were performed with a bridge prosthesis supported by three implants. The total duration of treatment was 8 weeks. Functional results are good.

The method can be used in maxillofacial surgery and plastic surgery. For this, a distractor can be used (Fig. 2, where 1 is a screw (implant), 2 is a coupling), which is an implant or screw with an external (conical or cylindrical) screwed part - a coupling (nut) with an internal thread. The implant in this device is used for defects, for the restoration of which, in addition to increasing bone tissue, prosthetics with fixation on the implant are required, in other cases a screw is used. An implant (screw) contains an external or internal hexagon or a tetrahedron (other polyhedrons), an internal cone, thread or slots, as well as a combination of these elements. The coupling usually contains an external hexagon or a tetrahedron (or other polyhedrons).

Most preferred is the following application of the distractor. Under anesthesia, an incision and detachment of the mucocutaneous flap, compactosteotomy or osteotomy are made along the border (fully or partially) of the enlarged portion of the bone skeleton. A bone canal (bed) is created with a special drill, which crosses the line of fracture (for injuries) or the line of osteotomy (corticotomy), a screw with a sleeve is screwed in, crossing the line of osteotomy (fracture), but without bringing the end of the screw to the bottom of the channel. The clutch should abut against the bone. Thus, a screw (implant) with a sleeve will attract bone segments (fragments) separated by osteotomy or fracture and create a compressive tension between the fragments. Then, after the bone regenerate is formed, the clutch is unscrewed a few turns and a screw (implant) is screwed, resting its end against the channel bottom, while the screw (implant) will push apart bone segments (fragments) separated by osteotomy (or as a result of a fracture) and create tensile stress, stimulating bone formation. Thus, we obtain controlled dosed compression and distraction of the regenerate, regulating osteosynthesis. When the bone section (fragment) is completely cut off, it is fixed (with a spoke, screw, bone nail, wire) to keep it from turning during rotation of the implant. The distractor is introduced with self-threading or pre-cutting the counter thread with a tap.

The method can be performed without flaking the flap transdermally, while the osteotomy and the implant (screw) are inserted through small incisions. In plastic surgery, after achieving the necessary increase in bone tissue, the screw is removed by unscrewing it from the bone tissue.

The advantages of the method in the oral cavity:

- one operation combines two operations at once - two technical results - an increase in bone tissue and intraosseous implantation;

- the implant, immersed in bone tissue, “builds up” the necessary amount of bone tissue;

- the direction of mechanical action corresponds to the distraction vector as much as possible.

In other departments and for fractures, it allows:

- achieve bone enlargement with a simple design - a screw;

- conduct operations in hard-to-reach areas, inconvenient for the installation of a distraction apparatus;

- carry out bone enlargement in multiple and multidirectional areas of distraction;

- fix fragments and build up lost bone tissue;

- does not cause additional trauma associated with the need to fix the distraction apparatus to the bone.

Claims (9)

1. A method of increasing bone tissue, including flap detachment, osteotomy and / or compactosteotomy and the insertion of a threaded implant, characterized in that the increase in bone tissue is achieved by controlled screw distraction, which consists in creating a bone bed into which an intraosseous implant is inserted, upon reaching the bottom of the bed, the implant continues to rotate in place, due to which the bone section cut off by the osteotomy moves along the thread of the implant in the direction opposite to the direction of insertion of the implant. 2. The method of increasing bone tissue according to claim 1, characterized in that the enlargement of the alveolar bone is achieved by introducing a threaded implant consisting of a threaded part with a thread pitch from 0.6 to 2.0 mm and a thread profile height of 0.2 to 1, 5 mm. 3. A method of increasing bone tissue according to claims 1 and 2, characterized in that the implant contains a cervical part or a neck. 4. The method of increasing bone tissue according to claims 1 to 3, characterized in that a bone bed is created that has a diameter smaller than the diameter of the threaded part of the implant by the height of its thread profile, for introducing the implant with self-cutting, and the length of the formed bed is less than the length of the inserted implant by the size of the subsequent increase in bone tissue. 5. A method of increasing bone tissue according to claims 1 to 4, characterized in that for the simultaneous increase in the height and thickness of the alveolar process, longitudinal section of the bone tissue along the crest of the alveolar process is additionally performed. 6. A method of increasing bone tissue according to claims 1 and 2, characterized in that the increase in the alveolar bone is achieved due to distraction tension in the bone tissue. 7. A method of increasing bone tissue according to claims 1 and 2, characterized in that the enlargement of the alveolar bone is produced gradually, due to repeated rotation of the implant. 8. The method of increasing bone tissue according to claims 1 and 2, characterized in that the increase in the alveolar process is achieved simultaneously by rotating the implant. 9. The method according to claims 1 to 8, characterized in that a threaded rod with an external screwed part is introduced in the form of a conical or cylindrical sleeve with an internal thread.

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