Abstract:
Dental prosthesis stabilizer consisting of at least two arms ( 4-5 ), connected to one another by means of a hinged joint ( 6 ), whereby the hinged joint ( 6 ) is equipped with a spring ( 26 ), and whereby the arms ( 4-5 ) are provided with junctures ( 13,23 ) in order to fix these arms to a dental prosthesis, and whereby at least one of the arms ( 4-5 ) can be extended.

Description:
BACKGROUND OF THE INVENTION 
     A) Field of the Invention 
     The present invention concerns a dental prosthesis stabilizer, in particular a device which makes it possible to stabilize an upper prosthesis and a lower prosthesis in relation to one another. 
     In particular, the invention concerns a dental prosthesis stabilizer which makes sure that the upper prosthesis remains pressed against the upper jaw, and the lower prosthesis against the lower jaw when the mouth is opened. 
     B) Discussion of the Related Art 
     Connections between an upper prosthesis and a lower prosthesis which are equipped with a spring so as to keep the upper prosthesis and the lower prosthesis pressed against the respective jaws when the mouth is opened have already been long known. 
     Such connections between an upper and a lower prosthesis are described among others in Belgian patent No. 1,006,478 and in British patent No. 784,540. 
     However, the known connections between either an upper prosthesis and a lower prosthesis, or between an upper prosthesis or a lower prosthesis and the natural teeth have as a major disadvantage that they cannot follow the natural movements of the jaws, as a result of which the prosthesis does not fit up well to the respective jaw when the mouth is opened. 
     The maxillary joint is indeed situated above and behind the oral cavity, whereas the hinge of a mutual connection between prostheses or between a prosthesis and the natural teeth is necessarily situated in the oral cavity. 
     As the maxillary joint on the one hand and the above-mentioned connection on the other hand hinge in different places, this has for a result that the prostheses, when the mouth is being opened, make a turning movement having another middle point than that of the respective jaw. 
     This results in that, when the mouth is opened, the prosthesis will still fit up to the respective jaw in the front of the oral cavity, but this will certainly not be the case in the back of the oral cavity. 
     SUMMARY OF THE INVENTION 
     The invention aims a dental prosthesis stabilizer which has been improved in several respects compared to the existing connections of dental prostheses. 
     In particular, the invention aims a dental prosthesis stabilizer whereby the above-mentioned disadvantage and other disadvantages of the known connections between dental prostheses are excluded or are at least minimized. 
     To this aim, the invention concerns a dental prosthesis stabilizer, consisting of at least two arms, connected to one another by means of a hinged joint which is equipped with a spring, provided with junctures in order to fix them to a prosthesis, whereby at least one of these arms can be extended. 
     Preferably, the arm, which is connected to the upper prosthesis, can be extended, to which end said arm is equipped with telescopic parts which slide into one another, in between which is situated a helicoidal compression spring. 
     According to a preferred embodiment, the arm is provided with a ball, and the upper prosthesis is provided with a cavity, such that the ball forms a snap connection together with the cavity. 
     The hinged joint between the arms of the dental prosthesis stabilizer may consist of disc-shaped parts of the above-mentioned arms, in between which is situated a torsion spring, and whereby these disc-shaped parts are connected to one another by means of a bayonet catch. 
     The arm of the dental prosthesis stabilizer which is connected to the lower prosthesis is preferably provided with a knob-shaped protrusion, and the lower prosthesis is preferably provided with a slot in which said knob-shaped protrusion can be provided and can slide into. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order to better explain the characteristics of the invention, the following preferred embodiment of a dental prosthesis stabilizer according to the invention is described as an example only without being limitative in any way, with reference to the accompanying drawings, in which: 
     FIG. 1 represents a side view of a dental prosthesis, provided with a dental prosthesis stabilizer according to the invention; 
     FIG. 2 represents a view, analogous to that in FIG. 1, but with the dental prosthesis in open position; 
     FIG. 3 represents a section according to line III-III in FIG. 2; 
     FIG. 4 represents a section according to line IV-IV in FIG. 2; 
     FIG. 5 represents a more detailed view with a partial cut-out of the part which is indicated in FIG. 2 by F 5 ; 
     FIG. 6 represents a schematic view in perspective of a dental prosthesis, provided with a dental prosthesis stabilizer according to the invention; 
     FIG. 7 represents a view similar to that in FIG. 6, but with the dental prosthesis in open position; 
     FIG. 8 represents a dental prosthesis stabilizer according to the invention, disassembled and in perspective. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The invention concerns a dental prosthesis stabilizer  1  with which an upper prosthesis  2  and a lower prosthesis  3  are attached to one another. 
     The dental prosthesis stabilizer  1  mainly consists of two arms  4  and  5  which are attached to one another by means of a hinged joint  6 . 
     The two arms  4  and  5  are attached to one another by means of a bayonet catch  7 . 
     The arm  4  consists of two telescopic parts  8  and  9  which slide into one another. 
     The part  8  of the arm  4  consists of a cylindrical housing  10  which is closed on one end, whereby the housing  10  is provided with a protrusion  12  at the end  11 , onto which is fixed a juncture  13  for fixing the arm  14  on the upper prosthesis  2 , whereby this juncture in the present embodiment consists of a ball, which further also has  13  as a reference number. 
     On the other end  14 , the cylindrical housing  10  has an inward directed collar  15  on the inner wall. 
     The part  9  of the arm  4  consists of a small rod  16  which is provided with an outward directed collar  17  on one end, whereas the other end is transformed into a disc-shaped part  18  which is part of the hinged joint  6 . 
     Further, the arm  4  has a helicoidal compression spring  19 . 
     The helicoidal compression spring  19  is shifted in the part  8  of the arm  4  up against the stop  20 , after which the above-mentioned collar  17  of the rod  16  is snapped in the part  8  of the arm  4  behind the compression spring  19  by placing the collar  17  behind the collar  15  of the housing  10 , which is possible as the housing  10  is made of a somewhat elastic material. Thus, the compression spring  19  is jammed, but nevertheless released, between the stop  20  of part  8  and the end of the rod  16  of part  9 . 
     The arm  5  consists of a bent rod  21 , onto which is provided a protrusion  22  on one end onto which is fixed a juncture  23  for fixing said arm  5  on the lower prosthesis  3 , whereby said juncture in this embodiment consists of a knob-shaped protrusion in the shape of an oblate ellipsoid, whose short axis  24  is more or less parallel to the bent rod  21 , and which further also has  23  as a reference number. 
     The other end of the rod  21  is transformed into a disc-shaped part  25  which is similar to the disc-shaped part  18  of the arm  4 . 
     The hinged joint  6  consists of the above-mentioned disc-shaped parts  18  and  25  of the respective arms  4  and  5 , in between which is situated a torsion spring  26 . In the disc-shaped parts  18  and  25  have been made recesses  27  for the torsion spring  26 , such that the ends  28  and  29  of the torsion spring  26  in these recesses  27  rest against the stops  30  of the disc-shaped part  18 , against the disc-shaped part  25  respectively. 
     The torsion spring  26  is released when the arms  4  and  5  form an angle of 170 degrees in relation to one another, which more or less coincides with the position of the prosthesis as the mouth is opened wide. 
     On the side wall of the recesses  27  in the disc-shaped part  18  are provided edges  31 , which are designed such that they form a bayonet catch together with edges in the disc-shaped part  25 , such that the arms  4  and  5  can be disassembled when they are turned at an angle of 190 to 200 degrees in relation to one another. This is some 20 degrees more than the position represented in FIG. 2, in which the mouth is opened wide. 
     The dental prosthesis stabilizer  1  is easily attached to the dental prosthesis as follows. In the upper prosthesis  2  is provided a cavity  32  on either side, such that the diameter of the opening  33  of the cavities  32  is a fraction smaller than the diameter of the ball  13  of the arm  4  of the dental prosthesis stabilizer  1 . The ball  13  can thus be snapped in the corresponding cavity  32  of the upper prosthesis, loosened from it respectively. 
     In the lower prosthesis  3  is provided a slot  34  on either side, whereby the width of the opening  35  of said slots  34  is a fraction larger than the short axis  24  of the knob-shaped protrusion  23 , but smaller than the long axis of the above-mentioned protrusion  23 . 
     The lower prosthesis  3  is fixed to the dental prosthesis stabilizer  1  by turning it such that the longitudinal direction of the corresponding slot  34  is parallel to the arm  5 . 
     The knob-shaped protrusion  23  of the arm  5  is subsequently pushed in the slot  34 , after which the lower prosthesis  3  is tilted back into its normal position. 
     As the axis  24  of the knob-shaped protrusion  23  is no longer at right angles to the longitudinal direction of the slot  34 , the knob-shaped protrusion  23  will at that moment be locked in a slidable manner in the above-mentioned slot  34 . 
     After the assembly, when the compression spring  19  and the torsion spring  25  are released, the prosthesis will be situated in a position which practically coincides with the position of the prosthesis when the mouth is opened wide. 
     The working of the dental prosthesis stabilizer  1  is very simple and as follows. 
     When the mouth is opened, the torsion spring  26  on the one hand and the helicoidal compression spring  19  on the other hand are released. 
     Thanks to this joint release, the lower prosthesis hinges around the hinged joint  6 , and the lower prosthesis  3  is simultaneously shifted vertically in relation to the upper prosthesis  2 . 
     In other words, the joint release of the torsion spring  26  and the compression spring  19  makes sure that when the mouth is opened, the lower prosthesis  3  remains pressed against the jawbone. 
     The forward or backward movement of the lower jawbone is set off by the prosthesis as the dental prosthesis stabilizer  1  is connected to the lower prosthesis  3  in a sliding manner by means of the knob-shaped protrusions  23  which are situated in the slots  34 . 
     It is clear that in this manner is obtained a dental prosthesis stabilizer  1  which provides for an optimal connection of the prosthesis against the jawbones and which moreover guarantees a large freedom of movement for the mouth, so that wearing a dental prosthesis is much more comfortable. 
     Moreover, the prosthesis can be easily disassembled, whereby the dental prosthesis stabilizer  1  and the dental prosthesis on the one hand, and the arms  4 - 5  of the dental prosthesis stabilizer  1  on the other hand can be easily disassembled, after which all parts of the dental prosthesis stabilizer  1  can be thoroughly cleaned. 
     The invention is by no means limited to the above-described embodiments represented in the accompanying drawings; on the contrary, such a dental prosthesis stabilizer can be made in all shapes and dimensions while still remaining within the scope of the invention.