WO2018100221A1

WO2018100221A1 - Mandibular distractor

Info

Publication number: WO2018100221A1
Application number: PCT/ES2017/070783
Authority: WO
Inventors: Pilar RUBIO BUENO
Original assignee: Fundación Para La Investigación Biomedica Del Hospital Universitario De La Princesa
Priority date: 2016-11-29
Filing date: 2017-11-29
Publication date: 2018-06-07
Also published as: ES2670449B1; ES2670449A1

Abstract

The present invention relates to a mandibular distractor comprising two connected and cooperating distension arms (1, 2), each of which is equipped with one or more attachment means (3, 3') for attaching to the jaw of an individual. Advantageously, the connection between the distension arms (1, 2) is made by means of a system comprising a cap (7) included in one of the arms (1) and a coaxial rod (8) included in the other arm (2), wherein the cap (7) and rod (8) are configured to move relatively in a longitudinal manner, causing the distension of the ascending ramus (4) of the jaw in relation to the main body (5) of the jaw during use. The distractor also comprises an internal traction system (9) housed in the cap (7) and connected to the rod (8) by means of a transmission means (10) designed to transmit the movement generated by the actuating system (9) to the rod (8), thereby causing mandibular distension.

Description

DESCRIPTION

MANDIBULAR DISTRACTOR FIELD OF THE INVENTION

The present invention relates to a mandibular distractor and a kit comprising said distractor, preferably applied to jaw lengthening techniques in the field of maxillofacial surgery.

BACKGROUND OF THE INVENTION

Mandibular distractors are devices used in the field of surgery, mainly to correct malformations in the jaw by means of bone distraction. This technique is less aggressive than other surgical techniques and has undergone a great development in the last decades, giving rise to numerous technical applications and a great variety of devices oriented to this field.

In general, the mandibular distraction technique involves performing a cut or osteotomy in the jaw and fixing it, under anesthesia, of an external or internal device (called a distractor) that is equipped with means for separating each mandibular portion separated by said cut. Therefore, by applying said means to the cutting region, stretching of the bone callus is caused, effectively lengthening the mandibular bone.

Typically, distracting devices allow elongation of the jaw of the order of 1 mm / day, which can be performed at the patient's home after undergoing surgery. Usually, a distinction is made between a first phase of elongation (which usually lasts a few weeks) and a subsequent phase of consolidation, over a period of several months.

Although the different known mandibular distractors are an effective solution to obtain the effect of bone elongation pursued, they all still have limitations related to the technicality of their application to the patient, since their volume causes, once they are fixed to the jaw, which protrude from the bottom of it. An example of such distractors is described in the patent US 6423069 B1, whose essential approach is illustrated in Figure 1 of this document.

The aforementioned limitations make the use of these devices more difficult to drive if they protrude through the lower part of the jaw, that is, both the part of the distractor that moves the distal segment of the jaw, and the distractor drive system. This inconvenience can cause problems such as hooks on clothes or hair, and even trauma, especially in children, who are more active and are not as aware as adults of the precautions required while the distractor is fixed to the jaw.

Additionally, the fact that a portion of the distractor continuously protrudes from the jaw itself constitutes a risk zone that can lead to possible skin infections or even deeper and therefore more serious infections.

On the other hand, the fact that part of the prosthesis stands out as a foreign element precisely in an area as visible as the face, creates problems related to the aesthetics of the patient, with its possible negative effect on the social and working life of the same, as a result of the excessive volume of known distractors and their corresponding application techniques.

Last but not least, the fact that the distractor has an emergency through the skin requires a second surgical procedure under general anesthesia to remove the device after the end of the consolidation period, which represents an additional risk taking into account that some patients present associated comorbidities.

The present invention proposes a solution to the aforementioned technical problems, by means of a novel mandibular distractor of titanium or any other similar alloy that can be left permanently anchored to the bone (such as joint prostheses) or of a compatible absorbable, miniaturized material and configured to adapt to the space between the masseter muscle and the external bone cortex of the ascending limb of the jaw, and in intimate apposition to the latter, without adding an excessive additional volume on it and without exceeding, the plate or system of lower fixation, the anatomical limit of the basilar of the mandibular angle, called gonion cephalometric point (Go), which minimizes or completely prevents foreign body reaction problems, as is usual in today's devices.

BRIEF DESCRIPTION OF THE INVENTION

In order to solve the problems described in the previous section, a first object of the invention relates to a mandibular distractor comprising two connected and cooperating distension arms, each of which is equipped with one or more fixing means to the jaw of an individual, and where said fixation means are configured to anchor, during the use of the distractor, a first arm of distention to the proximal segment of the ascending limb of the jaw, and a second arm of distension to anchor to the distal segment of the ascending branch of the jaw, the mentioned segments (proximal and distal) being separated by an osteotomy (surgically controlled fracture).

In a preferred embodiment of the invention, the connection between the stretching arms is made by a system of a bushing comprised in one of the arms and a coaxial rod comprised in the other arm, where said bushing and rod are configured to move relatively longitudinally promoting, during its application, the elongation or distension of the proximal fragment of the ascending limb of the jaw in relation to the distal fragment of the jaw.

In another preferred embodiment of the invention, the distractor also comprises an internal traction system housed in said bush and connected to the rod through a transmission means, adapted to transmit the movement generated by the drive system to the rod, propitiating the mandibular distention.

In another preferred embodiment of the invention, the internal traction system is configured with wireless or cable connection means to an external activation system, operable remotely from the distractor itself, for the activation of said internal traction system.

In another preferred embodiment of the invention, the external activation system comprises a remote operated electromagnetic device.

In another preferred embodiment of the invention, the electromagnetic device actuated to distance comprises a set of cooperating magnets arranged in the external system and in the internal system.

In another preferred embodiment of the invention, the external activation system comprises a device connected to the internal traction system by means of an intraoral cable.

In another preferred embodiment of the invention, the attachment of the intraoral cable to the internal tensile system is removable.

In another preferred embodiment of the invention, the distractor comprises titanium, or other similar alloy and / or a resorbable material as manufacturing material.

In another preferred embodiment of the invention, the fixing means comprise fixing screws of titanium, or other similar alloy and / or of a resorbable material.

In another preferred embodiment of the invention, the internal traction system has a lateral access perpendicular to the bushing, an upper access parallel to the bushing, or a double diametral access perpendicular to the bushing, on both sides thereof.

A second object of the invention relates to a mandibular distention kit comprising a distractor according to any of the embodiments described herein, in combination with an external activation system of said distractor. Problems associated with known distractors protruding like an appendix from the lower part of the jaw are avoided with the distractor of the invention. Likewise, the distractor of the invention, by being at a distance from the user's skin, prevents trauma and any other type of interference, since, externally, the distractor of the invention has no element in sight. In addition, as there is no exposure to the outside of the distractor, the risk of skin infections and deeper infections is also reduced.

As for the aesthetic aspect of the distractor, as it does not stand out from the user's face, it will be easier for the user to return to work, thus reducing the downtimes. This temporary factor is especially important in adult patients, since it is possible to talk about a month of activation or stretching of the callus and between six and twelve months of consolidation.

Finally, although with greater relevance if the above problems are possible, there is the risk associated with all types of surgical interventions, a risk that is aggravated in patients with associated diseases, which is called associated comorbidity. Indeed, the distractor of the invention allows avoiding this second surgery, since it is not necessary to remove the device once the consolidation period is over.

The distractor of the invention can be used to correct malformations in the jaw and also to solve other conditions that can be solved by a mandibular enlargement, by increasing the upper pharyngeal volume and tensing the muscles, such as sleep apnea in adults. , whose prevalence, according to the most recent publications, could reach 25% of the adult population; or obstructive apnea in children, who may need permanent tracheotomy if the obstruction is not surgically resolved.

DESCRIPTION OF THE FIGURES

Figure 1 shows an externally operable mandibular distractor, belonging to the state of the art.

Figures 2a-2b illustrate a schematic of the distractor of the invention in use, where its main elements can be seen. Figures 3a-3b show two embodiments of the distractor of the invention, in combination with an external activation system, operable at a distance.

NUMERICAL REFERENCES USED IN THE FIGURES In order to help a better understanding of the technical characteristics of the invention, the aforementioned Figures 1, 2a-2b and 3a-3b are accompanied by a series of numerical references where, for illustrative and non-limiting purposes , the following is represented:

(4) Ascending branch of the jaw

(5) Main jaw body

(6) Osteotomy

<7) Cap

(8) Stem

(9) Internal traction system

(10) Transmission medium, screw, threaded, piston

(1 1) External distractor activation system

(12) Intraoral cable

DETAILED DESCRIPTION OF THE INVENTION

As shown in Figure 1 of this document, known mandibular distractors generally comprise two connected and cooperating mandibular distention arms (1, 2), each of which is equipped with one or more fixing means ( 3, 3 ') to the jaw of an individual. Said fixing means (3, 3 ') are configured to anchor, during the use of the distractor, a first arm (1) of distension to the ascending branch (4) of the jaw, and to anchor the second arm (2) of distension to the main body (5) of the jaw, said ascending branch (4) and said main body (5) being separated by an osteotomy (6). The fixing means (3, 3 ') preferably comprise fixing screws.

As evolution of the known distractors and as represented in Figures 2a-2b in the distractor proposed by the present invention, the connection between the arms (1, 2) of distension is preferably carried out by means of a bushing system (7) comprised in one of the arms (1) and of a coaxial rod (8) comprised in the other arm (2). Said bushing (7) and rod (8) are configured to move relatively longitudinally, thus causing distension of the ascending limb (4) relative to the main body (5) of the jaw.

To carry out the relative displacement between the bushing (7) and the rod (8), the distractor of the invention is advantageously equipped with an internal traction system (9) housed in said bushing (7) and connected with the rod (8) through a transmission means (10) such as a screw, threaded, a piston and / or the like, which transmits the movement generated by the internal traction system (9) to the rod (8), promoting the mandibular distention As mentioned, the internal traction system (9) is an internal element that is preferably housed in the bushing (7), in order not to add additional volume to the assembly formed by the distractor. Although Figures 2 and 3 of this document show an example where the internal traction system (9) has a side access, it can be arranged, in other embodiments, parallel to the bushing (7), or with a double diametral access perpendicular to the bushing (7), on both sides thereof, so that the distractor can be used interchangeably on the left or right side of the jaw.

On the other hand, for the activation of the internal traction system (9) and as shown in Figures 3a-3b, it may have wireless or cable connection means to an external activation system (1 1), operable to distance from the distractor himself. In a preferred embodiment of the invention, the distractor external activation system (1 1) may comprise, for example, a remote-operated electromagnetic device. Thus, through the configuration of said device and its application to the system (1 1), it receives operating instructions that activate the internal traction system (9) and propitiate the mandibular distention. Said electromagnetic device may comprise a set of magnets arranged in the external system (1 1) and in the internal system (9).

In another preferred embodiment of the invention, the external activation system (1 1) may comprise an intraoral device, for example connected via a cable (12) to the internal traction system (9). By said embodiment, the cable (12) is connected to said system (9) prior to its fixation to the patient's jaw, so that, once fixed, the cable (12) is exited through a small orifice of the patient's intraoral mucosa. Said cable (12) is connected, externally, to the activation set of the external system (1 1), to send the corresponding operating instructions to the internal traction system (9). Once the mandibular distension phases are completed, it is possible to remove the cable (12) (for example, by pulling it), releasing it from the distractor.

Finally, another aspect of the invention relates to a kit comprising a mandibular distractor according to any of the embodiments described herein, in combination with an external activation system (1 1). As proposed, the distractor and the kit of the invention can be applied completely internally to the patient, while maintaining its external activation ability. Thus, once the period of distension is over, it is possible to remove the external activation system (1 1) by keeping the distractor fixed to the jaw, either to complete the period of bone consolidation of the treatment, or permanently. For this purpose, resorbable type materials, or highly biocompatible titanium and which can be left for life anchored to the bone as if it were a prosthesis or osteosynthesis material, are preferably used. As a further advantage of the invention, the symmetrical arrangement of the two arms (1, 2) of the mandibular distention and of the fixation means (3, 3 '), according to the embodiment shown in Figures 2a-2b makes the distractor can use interchangeably for the right or left side of the jaw. This represents a great functional and economic advantage both in production and in its application to the patient, since it reduces intervention times and eliminates the risk of confusion of using a device on the opposite side.

Also, another advantage of the distractor of the invention with respect to the state of the art is that it allows its fixation at the level of the mandibular basilar. Until now, known distractors are based on a bulky stem that, when submerging the device, pose a greater risk of tissue damage at the start of the lengthening treatment. This risk is eliminated with the proposed solution, where the intervention and treatment space is substantially reduced, for the benefit of the patient.

Claims

one . - Mandibular distractor comprising two connected and cooperating distension arms (1, 2), each of which is equipped with one or more fixing means (3, 3 ') to the jaw of an individual, where said fixing means (3, 3 ') are configured to anchor, during the use of the distractor, a first arm (1) of distension to the ascending limb (4) of the jaw, and to anchor the second arm (2) of distension to the main body (5) of the jaw, said ascending branch (4) and said main body (5) being separated by an osteotomy (6);

characterized in that the connection between the arms (1, 2) of distension is made by a system of a bushing (7) comprised in one of the arms (1) and of a coaxial rod (8) comprised in the other arm (2 ), where said bushing (7) and rod (8) are configured to move relatively longitudinally, promoting, during application, the stretching of the ascending branch (4) in relation to the main body (5) of the jaw;

and because the distractor also comprises an internal traction system (9) housed in said bushing (7) and connected to the rod (8) through a transmission means (10), adapted to transmit the movement generated by the internal traction system (9) to the rod (8), promoting mandibular distention.

2. - Mandibular distractor according to the preceding claim, wherein the internal traction system (9) is configured with wireless or cable connection means to an external activation system (1 1), operable remotely from the distractor itself for the activation of said internal traction system (9).

3. - Mandibular distractor according to the preceding claim, wherein the external activation system (1 1) comprises a remotely operated electromagnetic device.

4. - Mandibular distractor according to the preceding claim, wherein the remote-operated electromagnetic device comprises a set of cooperating magnets arranged in the external system (1 1) and in the internal traction system (9).

5. - Mandibular distractor according to claim 2, wherein the external activation system (1 1) comprises a device connected to the internal traction system (9) by means of an intraoral cable (12).

6. - Mandibular distractor according to the preceding claim, wherein the connection of the intraoral cable (12) to the internal internal traction system (9) is removable.

7. - Mandibular distractor according to any of the preceding claims, comprising titanium and / or a resorbable material as manufacturing material.

8. - Mandibular distractor according to any of the preceding claims, wherein the fixing means (3, 3 ') comprise fixing screws.

9. Distractor according to any of the preceding claims, wherein the transmission means (10) comprises a screw, threaded and / or a piston.

10. Distractor according to any of the preceding claims, wherein the internal traction system (9) has a lateral access perpendicular to the bushing (7), an upper access parallel to the bushing (7), or a double diametral access perpendicular to the bushing ( 7), arranged on both sides of it.

1 1 .- Mandibular distention kit comprising a mandibular distractor according to any of the preceding claims, in combination with an external activation system (1 1) of said distractor.