AU2021100114A4

AU2021100114A4 - An alveolar distractor

Info

Publication number: AU2021100114A4
Application number: AU2021100114A
Authority: AU
Inventors: Maroti B. Wadewale; Harsh Desai; Mrimingsi Kri; Prajwalit P. Kende; Ashish Sarda; Jayant Shivaji Landge
Original assignee: BWadewale Maroti
Current assignee: BWadewale Maroti
Priority date: 2021-01-08
Filing date: 2021-01-08
Publication date: 2021-04-08
Anticipated expiration: 2029-01-08

Abstract

An extra osseous alveolar distractor is disclosed and includes a base plate (102) with a plurality of buccal cavities (104) along a longitudinal axis of said base plate (102) at specific distance from each other, wherein said base plate (102) comprises a housing (106) disposed at a center of said base plate (102). An internal assembly (108) comprises at least two micro-bevel gears (110) placed perpendicular to each other with a threaded screw (112) inserted normal to a first micro bevel inside an annular section of said first micro-bevel and parallel to a second micro-bevel gear in a manner when said second micro-bevel gear is rotated, a rotational motion is generated within said threaded screw (112) in order to move up and down with respect to said base plate (102) from said first thorough hole of said housing (106). A transport plate (114) is linearly coupled to said base plate (102) via said threaded screw (112). 21 00 (3 L.

Description

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L. ANALVEOLAR DISTRACTOR FIELDOFINVENTION

The present invention generally relates to a field of mechanical engineering and particularly to the field of biomedical engineering. The present invention specifically relates to biomedical devices employed in dental science for the distraction of extra-skeletal bone.

BACKGROUND OF THE INVENTION

The decreased bony alveolus in vertical dimension is a common finding in patients going for prosthetic rehabilitation. They can result due to orofacial pathology, faciomaxillary injury or surgical procedures. Pre prosthetic surgery encompasses surgical maneuver for achieving an ideal bony and soft tissue contour for receiving a dental prosthesis. The various modalities include autogenous grafting materials, guided bone regeneration, alloplastic grafting materials, etc. The alveolar distraction osteogenesis is one such method that allows augmentation of alveolar ridge height with new bone formation as well as obtaining a significant increase in the surrounding soft tissues. The advantages quoted include offering a predictable result with low morbidity and infection rates and a significantly shorter waiting period for rehabilitation with implants (10 weeks) in comparison with the traditionally used methods. It has gained widespread popularity as a definitive treatment procedure for the correction of severely deficient alveolar bone. Alveolar distraction osteogenesis was first reported by Chin and Toth in 1996.

The alveolar distractors available may be classified as intraosseous (endosseous), extraosseous (subperiosteal) and tooth borne according to their insertion techniques. Extraosseous distractors are placed over the buccal surface of the alveolus subperiosteally, the intraosseous ones are placed through the transport segment and fixed to the basal segment by microplates toward the vector of distraction and the tooth borne devices are fixed to the tooth adjacent to the site of distraction.

The various types of alveolar distractors available are as; intraosseous and extra-osseous devices. The intraosseous devices include, a lead distractor, an Osteogenic Distractor, a Compact alveolar distractor, a Groningen Distractor Device, and a Maastricht intra-osseous distraction screw & Mainz distractor.

The application of LEAD distractor system was the first series of alveolar distraction demonstrated on patients. It is made of titanium and requires both upper and lower members of the device to be inserted horizontally into the osteotomy gap.

The OGD (endosseous distractor device) is used for mono-focal alveolar and small bone distraction thus can be indicated to heighten a small depressed area. The device has a body with external threads that are similar with a conventional regular size (3.75 mm) dental implant, which makes the surgical drilling procedure similar to implant placement. The base plug which will be stationary during active distraction has an internal thread hole to allow the distraction screw to engage during activation procedure. The thin distraction rod is placed inside the device and protrudes only through the crestal mucosa. The device can be retrieved easily without raising a mucoperiosteal flap unless implants are placed simultaneously during the distractor removal procedure. The base plug can be left in situ due to its material biocompatibility. However, if the basal plug interferes with the final implant position, it can be removed by threading the system's removal instrument onto the internal threads of the base plug.

The compact alveolar distractor application modified from the ACE alveolar osteogenic distractor, to provide larger distraction distance. It requires upper vertical socket tapping using 3.75 mm tapping drill to allow insertion of the device. The short and long device allows 7.5 mm and 10 mm vertical augmentation, respectively. Removal of the distractor and insertion of 3.75 mm implant into the same hole can be done in one procedure after 8 weeks of consolidation period to allow osseointegration if the initial position corresponds to the final implant position.

The Groningen Distractor Device (GDD) was introduced by the Groningen Expert Group, which is an intra-osseous system manufactured by KLS Martin. It was first reported in 2000. The miniature distraction device consists of two long distraction screws, two extensions, one guide screw and two titanium fixation screws to stabilize the extensions to the top of a transport bone segment. The top distraction screw is hexagonal whereas the caudal end has a smooth surface. When the distraction screw is activated, the cranial bone segment will be elevated.

The Maastricht intra-osseous distraction screw & Mainz distractor includes 2 types of intra-osseous distraction devices that can be applied for vertical alveolar bone augmentation. The first one is Maastricht intra-osseous distraction screw is made of titanium and comes in 10, 15 and 20 mm in length. The second one is Mainz distractor is a shorter intra-osseous device that comes in 5, 7, 9 and 11 mm in length.

The major advantages of extra-osseous system include minimal bone loss during distractor fixation, direct visibility of the distractor vector and not contaminating the dental implant insertion sites. However, the surgical procedure often requires more soft tissue reflection thus increasing the risk of jeopardizing the blood supply if not performed properly. The size of the devices occasionally cause discomfort from pressing the surrounding oral soft tissue. Some of extra-osseous devices include a TRACK 1.0 distractor was developed in 1999. The TRACK system comes with a variety of devices that can suit different anatomical requirements. All the new models consist of an additional plate at the bottom end of the distractor to minimize lingual or palatal tilting of the distraction vector during active distraction. A Verona distractor is an extra-osseous distractor developed by Medicon using micro-fixation. This system consists of a distraction rod with a 0.7 mm microplate on each side of the central rod for fixation to the basal bone and then another microplate to the upper transport segment. The enclosed distraction mechanism prevents the active component of the device from interfering with callus formation in the distraction gap and trapping of surrounding soft tissue.

The Vertical Distraction Alveolar Ridge system comes with two designs of single-tooth device and multi-tooth device. The use of resorbable plate in this system together with an external activation screw has been reported. This distractor can be inserted through a conventional vestibular incision with adequate mucosal reflection of the transport segment. The advantage of this technique is that the distraction screw can be removed without making an incision, leaving behind 2 resorbable plates. The resorbable plates are expected to dissolve within 12 months and screw holes completely replaced with bone.

China has also developed a device for alveolar distraction which comes in 8, 10, 12 and 15 mm in length. One full turn of its activation screw is equivalent to 0.4 mm. This device has an enclosed distraction rod to minimize soft tissue irritation and consist of 2 horizontal plates with 8 screw holes each for fixation on the bone segments.

A Multi-axial alveolar distractor is a vector control combined with a high-degree-of-freedom (DOF) ball-and-socket joint and were proposed as the design concept to allow the distractor to produce a cone trajectory motion range of up to 60 degree with respect to the transport screw (central axis). The alveolar distractor consists of an extra-osseous system with a ball-and-socket joint mechanism wielded to the base bone plate, which can be adjusted intraoperatively according to the preoperative plan in order to achieve vector control. The distractor can be angled up to 60 degree towards the buccal/lingual and mesial/distal sides. The ball and-socket joint can be relocked by tightening the hex nut after vector adjustment. The base bone plate consists of optional screw holes next to the ball-and-socket joint mechanism for fixing onto the residual bone, in order to achieve safety anchorage.

A Tooth borne alveolar distractor is a multidimensional device that used a custom-made abutment system with a cast framework that rests on the adjacent teeth. This hybrid device consists of a horizontal rod that is connected with two attachments, which need to be bonded on the adjacent tooth surface. It can be considered as a tooth-borne supported device and indicated for single tooth replacement. The device uses only fixation wire to transport the coronal segment of the alveolar crest.

The short comings of the presently available Intraosseous distraction system are, bone loss during distractor fixation; and contamination of the dental implant insertion sites. Moreover, theoretically the device can be removed simultaneously at implant placement stage and any ingrowth fibrous tissue at the distraction rod region needs to be removed. However, if the hole after distractor rod removal is too big for the planned implant diameter, the implants have to be placed at a second stage. Example in Lead distractor, Osteogenic Distractor (OGD), Compact alveolar distractor, Groningen Distractor Device (GDD), Maastricht intra-osseous distraction screw and Mainz distractor.

Some of the limitations associated with extra- osseous distraction system are as, direct visibility of the distractor in the oral cavity; increased joint size of the multi-axial alveolar distractor interferes with flap closure, which can lead to further dehiscence, for example multi axial alveolar distractor; and socially unacceptable to the patient. Furthermore, as the threaded distraction rod slowly rotated to attain vertical height, the opposing ridge or dentition may cause a hindrance. This may lead to continuous pressure and might lead to the fracture of the transport segment. If the rod is exposed, the interference by the rod on the surrounding structure may lead to masticatory problems and deflection of the transport segment.

In case of Tooth Borne alveolar distractor, some disadvantages associated with it are, not all the edentulous spaces have adjacent tooth present; it needs bonding to the tooth structure, puts the adjacent tooth into unnecessary stress; food lodgment may lead to additional problems of periodontitis. Some examples are TRACK 1.0 Distractor, Verona distractor, Vertical Distraction Alveolar Ridge system, China (Cibei Medical Treatment Appliance Co. Ltd.

The limitations and the disadvantages herein mentioned of the conventional and the existing devices of Intraosseous distraction system, extra- osseous distraction system, and Tooth Borne alveolar distractor can be overcome by the technical advancements of the present invention which is herein described in the later part of the present invention.

SUMMARY OF THE INVENTION

The present invention relates to an extraosseous distractor assembly configured for distracting and does not require any bone removal for its placement. The extraosseous distractor is completely submerged inside the mucous membrane.

In an embodiment of the present invention an extraosseous distractor is disclosed and comprising: a base plate with a plurality of buccal cavities along a longitudinal axis of said base plate at specific distance from each other, wherein said base plate comprises a housing disposed at a center of said base plate, wherein said housing comprises a first thorough hole at a top transverse plane of said housing and a second thorough hole a front plane of said housing; an internal assembly disposed within said housing of said based plate, wherein said internal assembly comprises at least two micro-bevel gears placed perpendicular to each other with a threaded screw inserted normal to a first micro-bevel inside an annular section of said first micro-bevel and parallel to a second micro-bevel gear in a manner when said second micro-bevel gear is rotated, a rotational motion is generated within said threaded screw in order to move up and down with respect to said base plate from said first thorough hole of said housing.

Another embodiment states that the extraosseous distractor further includes a transport plate linearly coupled to said base plate via said threaded screw, wherein said transport plate consists of a plurality of buccal cavities in parallel with said buccal cavities of said base plate, wherein said transport plate includes a through hole disposed at a center of said transport plate configured to accommodate said threaded screw; and an L-shaped key configured to be disposed within said second thorough hole and thereby inserted inside an annular section of said second micro-bevel gear, wherein when said L-shaped key is rotated clockwise, said second micro-bevel gear also rotates clockwise and connected said first micro-bevel gear starts rotating counter clockwise, wherein said counterclockwise rotation of said second micro-bevel gear generates a rotational motion to said threaded screw and thereby said threaded screw gains a linear motion in order to lift said transport plate coupled to said threaded screw upwards with respect to said base plate.

To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings

BRIEF DESCRIPTION OF FIGURES

These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

Figure 1 illustrates a block diagram of components installed in an extraosseous distractor.

Figure 2 illustrates an isometric view of components of the extraosseousdistractor.

Figure 3a-b illustrates a front view and a rear view of the extraosseous distractor.

figure 4a-b illustrates a top and a bottom view of the extraosseous distractor,

Figure 5a-b illustrates a right and a left view of the extraosseous distractor.

Figure 6 illustrates a three-dimensional view of at least two micro bevel gears installed in an internal assembly of the extraosseous distractor.

Figure 7 illustrates an Allen key or L-shaped key employed for activation of the extraosseous distractor.

Figure 8 illustrates an isometric view of the extraosseous distractor.

Figure 9 illustrates a prospective view of the extraosseous distractor.

Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present invention. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.

Reference throughout this specification to "an aspect", "another aspect" or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by "comprises...a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

The intraosseous distractor devices require bone removal for placement that results in weakening the bone, extraoral devices have an extra component that is visible in the oral cavity which causes occlusal hindrance and gives an unaesthetic look and the tooth borne device puts the adjacent tooth into unnecessary stress. The aim of the present invention is to develop a compact size device that causes no occlusal hindrance, prevents bone removal for its placement and also is acceptable to the patients with minimum complications.

The intraosseous distractor is an extraosseous type of distractor, that does not require any bone removal for its placement. The device is devoid of any extra-mucosal component, making it completely submerged inside the mucous membrane. Its compact size allows for easy re-approximation of the flap after placement. There is no hindrance to the opposing dentition by the activation rod that removes unnecessary forces acting on the regenerate thereby preventing regenerate fracture.

Figure 1 illustrates a block diagram of components installed in an extraosseous distractor. The extraosseous distractor apparatus includes a number of components which are described as follows.

A base plate (102) is provided with a plurality of buccal cavities (104) along a longitudinal axis of said base plate (102) at specific distance from each other, wherein said base plate (102) comprises a housing (106) disposed at a center of said base plate (102), wherein said housing (106) comprises a first thorough hole at a top transverse plane of said housing and a second thorough hole a front plane of said housing.

An internal assembly (108) is disposed within said housing (106) of said based plate (102), wherein said internal assembly (108) comprises at least two micro-bevel gears (110) placed perpendicular to each other with a threaded screw (112) inserted normal to a first micro-bevel inside an annular section of said first micro-bevel and parallel to a second micro-bevel gear in a manner when said second micro-bevel gear is rotated, a rotational motion is generated within said threaded screw (112) in order to move up and down with respect to said base plate (102) from said first thorough hole of said housing (106).

A transport plate (114) is linearly coupled to said base plate (102) via said threaded screw (112), wherein said transport plate (114) consists of a plurality of buccal cavities (116) in parallel with said buccal cavities (104) of said base plate (102), wherein said transport plate (114) includes a through hole disposed at a center of said transport plate (114) configured to accommodate said threaded screw (112).

An L-shaped key (118) is provided and is configured to be disposed within said second thorough hole and thereby inserted inside an annular section of said second micro-bevel gear (112), wherein when said L-shaped key (118) is rotated clockwise, said second micro-bevel gear also rotates clockwise and connected said first micro-bevel gear starts rotating counter clockwise, wherein said counterclockwise rotation of said second micro-bevel gear generates a rotational motion to said threaded screw (112) and thereby said threaded screw (112) gains a linear motion in order to lift said transport plate (114) coupled to said threaded screw upwards with respect to said base plate (102).

Figure 2 illustrates an isometric view of components of the extraosseous distractor. A base plate (206) is fixed relative to a transport plate (202). An internal assembly (208) is provided at the center of the base plate (206) and is coupled to the transport plate (202) through a threaded screw (204) which is disposed inside the internal assembly (208) and is perpendicular to the length of both the plates (202) and (206). A key hole is provided on a front of the assembly (208) in which a key or Allen key is inserted. The key when inserted inside said hole coupled with a bevel gear of very small size, and rotates the gear when said key is turned. The threaded screw (204) gains heigh in vertical direction and thereby moving said transport plate (202) upwards.

Figure 3a-b illustrates a front view and a rear view of the extraosseous distractor. The front view displays a key hole at the center of a base plate which is fixed with respect to a transport plate. Both the transport plate and the base plate have four holes or cavities with each two holes on the right and on the left side of the center where internal assembly is disposed. The holes are located at a distance of 10mm from each other in both the base plate and the transport plate.

Referring to Figure 4a-b which illustrates a top and a bottom view of the extraosseous distractor; and Figure 5a-b which illustrates a right and a left view of the extraosseous distractor. The base plate and said transport plate of said distractor consists of a length of 50 mm, wherein said housing enclosing said internal assembly accommodates a length of 3.7 mm at the center of said base plate. The said transport plate is kept at 3mm width and said base plate at 4 mm width, and said transport and base plates have 1.5 mm thickness with said central portion where housing is disposed is kept at 2 mm more than rest of said longitudinal area of said plates.

Each of said plurality of buccal cavities of said base plate and of the base plate have a diameter of 1.5mm.

Figure 6 illustrates a three-dimensional view of at least two micro bevel gears installed in an internal assembly of the extraosseous distractor. A first micro-bevel gear is placed horizontal along the length of said base plate inside the housing and the second micro bevel gear is placed or coupled normal to the first one. The first gear has a round annular section which is being threaded in order to receive said threaded screw and to rotate along with said gear. The second perpendicular gear has an annular section which is provided with an outer shape of the L-shaped key, so that when the key is rotated the second bevel gear also rotates and thereby transmitting the rotational motion towards the first horizontal micro-bevel gear.

Figure 7 illustrates an Allen key or L-shaped key employed for activation of the extraosseous distractor. The Allen key is displayed in figure. The L-shaped key consists of a long arm of length at least 50 mm perpendicular to a short arm of length at least 20 mm. When said L-shaped key is turned at least 1/4th of said second micro-bevel gear, said transport plate of said distractor gains a vertical height of at least 0.25 mm. The transport plate along with threaded screw on rotation of said L-shaped key gains a maximum height of at least 21 mm with respect to said base plate.

Figure 8 illustrates an isometric view of the extraosseous distractor. The holes or buccal cavities of the transport plate have less diameter than the cavities of the base plate. The reason is that the base plate which is fixed with respect to the transport plate, needs to receive the cavities of the transport plate.

Figure 9 illustrates a prospective view of the extraosseous distractor. The alveolar distractor has two plates measuring 50 mm in length out of which the central 3.70mm is occupied by the central assembly composed of the transport screw and bevel gear. The width of the transport plate is kept at 3mm and that of the fixed plate as 4mm. The plates are of 1.5 mm in thickness, the central portion of the device has a 2mm extra thickness to accommodate the internal assembly. The transport plate and the fixed plates have four holes of 1.50mm diameter each for securing the plates in position. The internal assembly has two micro-bevel gear placed perpendicular to each other and a threaded screw. The length of the threaded screw is 11.1 mm from the base plate. In rest position the threaded screw is 3.68mm above the transport plate. Rotation of the gear produces rotation of the threaded screw, which causes it to rise in height producing a linear motion for distraction. The only component that is extra-mucosal is the 2mm diameter Allen key slot. The Allen key for activation has a long arm of 50mm and a short arm of 20 mm. On turning the Allen key 1/4th, the distractor gains a vertical height of 0.25mm. The highest height that will be achieved by our device is 21 mm. The rate and rhythm of our distraction are as follows:

Rate of distraction with our device: 1.00mm/day

Rhythm of distraction with our device: 0.25mm x 4 times (1/4th turn four times).

The present invention discloses a distractor which is an improvement of the distractor design, and could lead to a further reduction in the number of complications and better results of alveolar distraction osteogenesis. It will increase the chances of patient's acceptance towards the distraction treatment and also, it will facilitate the surgeon to convince the patients. The herein proposed new design when introduced will emerge as a breakthrough in era of alveolar distractors.

The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts necessarily need to be performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any component(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all the claims.

Claims

WE CLAIM

1. An extra osseous alveolar distractor comprising:

a base plate (102) with a plurality of buccal cavities (104) along a longitudinal axis of said base plate (102) at specific distance from each other, wherein said base plate (102) comprises a housing (106) disposed at a center of said base plate (102), wherein said housing (106) comprises a first thorough hole at a top transverse plane of said housing and a second thorough hole a front plane of said housing;

an internal assembly (108) disposed within said housing (106) of said based plate (102), wherein said internal assembly (108) comprises at least two micro-bevel gears (110) placed perpendicular to each other with a threaded screw (112) inserted normal to a first micro-bevel inside an annular section of said first micro-bevel and parallel to a second micro-bevel gear in a manner when said second micro-bevel gear is rotated, a rotational motion is generated within said threaded screw (112) in order to move up and down with respect to said base plate (102) from said first thorough hole of said housing (106);

a transport plate (114) linearly coupled to said base plate (102) via said threaded screw (112), wherein said transport plate (114) consists of a plurality of buccal cavities (116) in parallel with said buccal cavities (104) of said base plate (102), wherein said transport plate (114) includes a through hole disposed at a center of said transport plate (114) configured to accommodate said threaded screw (112);

an L-shaped key (118) configured to be disposed within said second thorough hole and thereby inserted inside an annular section of said second micro-bevel gear (112), wherein when said L-shaped key (118) is rotated clockwise, said second micro-bevel gear also rotates clockwise and connected said first micro-bevel gear starts rotating counter clockwise, wherein said counterclockwise rotation of said second micro-bevel gear generates a rotational motion to said threaded screw (112) and thereby said threaded screw (112) gains a linear motion in order to lift said transport plate (114) coupled to said threaded screw upwards with respect to said base plate (102).

2. The extra osseous alveolar distractor as claimed in claim 1, wherein said base plate is configured to be fixed with respect to said transport plate, when said L-shaped key is being rotated inside said second thorough hole of said housing.

3. The extraosseous alveolar distractor as claimed in claim 1, wherein said base plate and said transport plate of said distractor consists of a length of 50 mm, wherein said housing enclosing said internal assembly accommodates a length of 3.7 mm at the center of said base plate.

4. The extra osseous alveolar distractor as claimed in claim 1, wherein said transport plate is kept at 3mm width and said base plate at 4 mm width, and said transport and base plates have 1.5 mm thickness with said central portion where housing is disposed is kept at 2 mm more than rest of said longitudinal area of said plates.

5. The extra osseous alveolar distractor as claimed in claim 1, wherein each of said plurality of buccal cavities of said base plate have a diameter of 2 mm for securing said plates in position and each of said buccal cavities of said transport plate have a diameter of 1.5 mm.

6. The extra osseous alveolar distractor as claimed in claim 1, wherein said L-shaped key consists of a long arm of length at least 50 mm perpendicular to a short arm of length at least 20 mm.

7. The extra osseous alveolar distractor as claimed in claim 1, wherein when said L-shaped key is turned at least 1/4th of said second micro bevel gear, said transport plate of said distractor gains a vertical height of at least 0.25 mm.

8. The extra osseous alveolar distractor as claimed in claim 1, wherein said transport plate along with threaded screw on rotation of said L shaped key gains a maximum height of at least 21 mm with respect to said base plate.

9. The extra osseous alveolar distractor as claimed in claim 1, wherein a rate of distraction is at least 0.5 mm per day.

10. The extra osseous alveolar distractor as claimed in claim 1, wherein when said L-shaped key is turned 1/4th twice, a rhythm of distraction is at least 0.25 multiplied by 2 mm.

FIXED BASE PLATE

106 HOUSING BASE PLATE BUCCAL CAVITIES 108 INTERNAL 104 ASSEMBLY 112 110 TWO MICRO- TRANSPORT BEVEL GEARS THREADED SCREW L-SHAPED KEY 116 114 MOVING 118 TRANSPORT PLATE TRANSPORT PLATE BUCCAL CAVITIES

FIG. 1

204

206

FIG. 2 208

FIG. 3a

FIG. 3b

FIG. 4a

FIG. 5a FIG. 5b FIG. 6

FIG. 7

FIG. 8

FIG. 9