WO2005082267A1

WO2005082267A1 - Device at an articulator

Info

Publication number: WO2005082267A1
Application number: PCT/SE2005/000304
Authority: WO
Inventors: Juan José PEREZ RODRIGUEZ
Original assignee: Perez Rodriguez Juan Jose
Priority date: 2004-03-02
Filing date: 2005-03-02
Publication date: 2005-09-09
Also published as: SE526091C8; SE0402227L; SE526091C2; SE0402227D0

Abstract

The invention relates to an arrangement (50) for an articulator (51) for holding cast impressions of upper and lower sets of teeth in conjunction with the testing and processing of the same and comprising two holders (7,11) capable of movement relative to one another, and each intended to hold its own cast impression of a set of teeth, with a spring device (6) arranged between the aforementioned holders (7,11). In accordance with the invention, the spring device is so arranged as to permit the holders to move forwards (52) and backwards (53) relative to one another from a neutral rest position (I) for the holders.

Description

Device at an articulator The present invention. relates to an arrangement for an articulator for holding cast impressions of upper and lower sets of teeth in conjunction with the testing and processing of these and comprising two holders capable of movement relative to one another and each intended to hold its own cast impression of a set of teeth with a spring device arranged between the aforementioned holders. Previously disclosed articulators of the kind referred to above are so arranged as to permit movement of the lower jaw only in a forward direction when the dental technician is working with them. The wish accordingly exists to be able to produce so-called retromandibular movements, that is to say a small movement in a backward direction, in order to cause the lower jaw to move correspondingly in a backward direction. The situation may present itself, for example, in which hard contact has occurred between the teeth when the patient moves his lower jaw in a backward direction during simultaneous contact by the teeth with one another. In this case, it is necessary for the dental technicians working with the impressions of the teeth in question to be able to effect movement of the lower jaw in a backward direction. Previously disclosed supports for the two cast sets of teeth in question, i.e. the upper jaw and the lower jaw, are normally fixed or, in the best case, are arranged in such a way that it is possible to displace one set in the articulator in one direction against the effect of a spring. Examples of previously disclosed articulators of the kind referred to above, which exhibit the disadvantages referred to above, are shown in, for example, US 4365955A, US 4687442 A, DE 4211008 Al, WO 00/21458 and US 5064372 A. Further patents US 102205 A, US 1055718 A, US 158809lΑ, EP 0054600 Al, EP 0594481 A3 and GB 2024018 A also show examples of articulators in which a shaft together with an upper set of teeth can be displaced against the effect of a spring. The rest position for the shaft is situated at the end position of the aforementioned spring, however, so that the spring effect is only present in conjunction with movement of the shaft in one direction. The principal object of the present invention is thus, in the first instance, to make available an arrangement, with the help of which the aforementioned problems can be solved, and which functions reliably and effectively and is also simple and economical to produce. The aforementioned object is achieved by means of an arrangement in accordance with the present invention, which is characterized essentially in that the spring device is so arranged as to permit the holders to move relative to one another respectively forwards and backwards from a neutral rest position for the holders. The invention is described below as a number of preferred illustrative embodiments, in conjunction with which reference is made to the accompanying drawings, in which: Figs. 1-7 show a first illustrative embodiment of the invention, where Fig. 1 shows an articulator in a perspective view, Fig. 2 shows a spring included in the aforementioned articulator viewed respectively from the side and from above in a preformed state, Fig. 3 shows the spring respectively in the unfolded state and in cross section, Fig. 4 shoes the articulator viewed from its long side, Fig. 5 shows the top part viewed from above, Fig. 6 shows the articulator viewed from one of its short sides from the rear, Fig. 7 shows the articulator viewed from above, Figs. 8-16 show a second illustrative embodiment of the invention, where Fig. 8 shows the aforementioned second articulator viewed from one of its short sides from behind, Fig. 9 shows the upper holder part in plan view, viewed from the top side, with a handle to enable all desirable movements to be reproduced, Fig. 10 shows the articulator viewed from one of its long sides, Fig. 11 shows it from above, Figs. 12-14 show in detail the attachment of a spring thereto, Fig. 15 shows the upper holder part viewed from above, Fig. 16 shows the bottom plate of the articulator viewed from below, Figs. 17-22 show a third illustrative embodiment of the invention, where Fig. 17 shows the aforementioned third articulator viewed from its long side, Fig. 18 shows it from above, Fig. 19 shows it from one of its short sides, Fig. 20 shows the upper holder part viewed as a plan view, and Figs. 21-22 show in detail the attachment of a spring between a shaft and a frame. An arrangement 50;150;250 of an articulator 51;151;251 to permit the holding of cast impressions of upper and lower sets of teeth in conjunction with the testing and processing of the said sets of teeth, and which comprises two holders 7, 11; 107 , 111; 207, 211, each capable of movement relative to the another for the purpose of holding its own cast impression of a set of teeth, respectively for the upper jaw and the lower jaw, with a spring device 6; 106; 206 arranged between the aforementioned holders, is shown clearly in Figs. 1, 8 and 18. In accordance with the invention, the spring device 6; 106; 206 is so arranged as to permit the holders 7, 11; 107, 111; 207, 211 to move relative to one another, respectively in a forward and backward direction, from a neutral rest position I, CI, CCI for the holders. More specifically, the upper holder 7; 107; 207 is so arranged as to move forwards 52; 152; 252 and backwards 53; 153; 253 from the aforementioned rest position I;CI;CCI. Thus only one holder 7; 107; 207 In the pairs of holders is so arranged as to be capable of moving against the effect of the aforementioned spring device, and the other holder 11; 111; 211 is so arranged as to remain rigidly immovable without the effect of any spring. The aforementioned moving holder 7; 107; 207 is so arranged as to be guided along an essentially straight movement path 13;113;213, i.e. a condyl path that is inclined at ca 10° from the horizontal plane viewed from one of its ends in a direction obliquely upwards and rearwards 53; 153; 253 and with a length of ca 16-17 mm. After performing repeated test bites in different positions with an ideal occlusion, it has been found that the aforementioned condyl path should exhibit an inclination of ca

10° in a direction upwards and rearwards and with a length of ca 16-17 mm. The length of the condyl path is longer to the front of the shaft than in the rearward direction. It is ca 11 mm in the forward direction, and it is then ca 5-6 mm in the rearward direction. It is thus possible to move the upper jaw forwards and rearwards against the effect of a spring. The aforementioned spring device is so arranged as to act on a transverse shaft 1; 101; 201, which is so arranged as to support the aforementioned upper holder 7; 107; 207 pivotally in a direction respectively upwards 54; 154; 254 and downwards

55; 155; 255 and respectively obliquely upwards 53; 153; 253 and obliquely downwards 52; 152; 252 respectively at both ends 56;156;256 and 57;157;257 of the shaft. The aforementioned illustrative embodiments differ in detailed respects, and for this reason they are described in turn in the following. The spring device in the first illustrative embodiment is provided by a formed leaf spring 6, which has the form of a mixture of the Greek letter omega and a sine curve. The aforementioned spring 6 is so arranged that it supports the shaft 1 between the two curved end parts 58,59 of the leaf spring in a suitable accommodating part 12, a bent so-called inward bend in the middle of the spring 6, and which is so arranged for fixing the shaft 1 in the spring 6. The spring 6, which consists of spring steel or some other suitable resilient material that lends itself to forming, can exhibit a spring force of ca 0.5 kN and is preferably tapering around the shaft, i.e. it is broader at the ends 6A, 6B than at the centre. The length can be ca 60 mm. In accordance with the embodiment of an articulator 151 shown in Figs. 8-16, the spring device 106 is formed by a spirally wound spring with a preferably square cross-sectional form, and appropriately rectangular, which is so arranged as to act at an angle X to the shaft 101, which is essentially 90°, at both of the respective ends of the shaft and with an amount of pretensioning in order to prevent the jaws from moving relative to one another. The spring 106 is attached by its one end 106A to the shaft 101 and is attached by its other, opposite end 106B to the fixed holder 111. The spring 106 is preferably fixed by means of a spring eye 158, which is attached to the shaft 101 by being passed onto the respective shaft end 156,157 at one end 106A of the spring, while the spring 106 is attached by its other, opposite end 106B to the aforementioned fixed holder 111 by means of a fixing screw 159. Finally, with regard to the embodiment of the articulator 251 shown in the drawings in Figs. 17-22, the spring device 206 is formed at the respective ends of the shaft by a spirally wound spring, the central axis 260 of which extends essentially parallel to the pivot shaft 201 for the moving part 207 of the articulator 251. The spring 206 is attached by its respective ends 261,262 respectively to the shaft 201 and to a fixed frame part 263. One end 261 of the spring is passed onto the shaft 201 pivotally relative to the shaft 201 or is hooked onto the shaft 201 and attached to it in such a way as to be incapable of rotating, while the other, opposite end 262 of the spring is attached to the frame part 263 in such a way that it is incapable of rotating relative to it or is capable of rotating relative to the frame part. The unique and distinctive feature of such an articulator 51; 151; 251 described in accordance with the foregoing is that it is now possible to reproduce the movement of the upper jaw in all directions, that is to say also in a direction rearwards

53;153;253, a possibility that was not available with previously disclosed solutions. In this way, the dentist avoids the need to grind away any inaccuracies directly in the patient's mouth, and this operation can now be performed by the dental technician before the dentures are placed in the mouth of the patient. Also shown in the drawings are additional details which solve a number of different problems with regard to respectively holding and adjusting the parts in the correct positions. Figs. 1-7 thus illustrate how a rounded, lateral stop 2 on the shaft 1 is provided for the purpose of enabling the upper jaw to be guided correctly backwards and forwards on the condyl path 13 and restricting the movement of the shaft 1 laterally, that is to say in the longitudinal direction of the shaft. A stop 3 is also provided for the adjustment of the height of occlusion, and a wing nut 5 and a screw 4, for example, permit correct adjustment of the desired height of occlusion. An upper part 7 arranged for supporting the upper jaw made of plaster exhibits recesses 8 to enable the upper jaw to be held effectively. Similar recesses are provided on the lower part 11 to enable the plaster in the lower jaw to be held in a corresponding fashion. The shaft 1 is shown in Fig. 1 in a neutral position I, from which it is capable of being displaced respectively forwards and backwards in the desired direction 52,53, against the effect of the spring 6. The spring 6 is screwed securely to the ends of the condyl path 13 by means of screws 9 on a raised upright 64. The aforementioned condyl path 13 is preferably not fully horizontal, but is inclined slightly, preferably at an angle A that lies between ca 5° and 20°, and preferably ca 10°, in a direction upwards viewed from the front handle 10 of the articulator on the upper part 7. The embodiment of the invention shown in Figs. 8-16 has its shaft 101 so arranged as to be capable of being actuated from a neutral position CI in such a way as to be displaced in a desired direction along the condyl path 113 respectively upwards and downwards, that is to say respectively backwards 153 and forwards 152, against the effect of the spring 106. Corresponding parts that are the same as those in the first illustrative embodiment of the invention have been given the same reference designations here. The condyl path 113 is formed by an oblique slot 165 in an upright 164 projecting upwards from the lower holder 111. The spring 106 is of equivalent strength to the previously mentioned spring and exhibits preferably rectangular cross-sectional form in order to enable it to achieve good strength and stability. The tension to the sides is ca 0.1 kN. It can be moved in a desired direction by means of a front handle 110 in the upper holder 107, and the aforementioned upper holder 107 can be detachably attached by means of an attachment

166 which comprises a handle 112 by means of which spring jaws

167 are forced apart, which engage around a rear longitudinal thickened part 168 of the upper holder 107. The plaster for the upper jaw is attached effectively around the holder 107 as far as its rear transverse curved boundary 113. The lower holder 111 exhibits ribbed pins 114, around which the plaster is fixed, and which hold the lower jaw securely according to the Galetti method. Fixing of the spring 106 to the shaft 101 is achieved by means of an eye 169, which fits in a recess 170 in the shaft 101. A wing nut 171 with an associated adjuster screw 172 in a bottom part 173 permits longitudinal adjustment of the lower holder 111 and the plaster model of the lower jaw supported thereon, in that the pins 114 are attached with the screw 172. The attachment of the lower jaw model is facilitated in this way, because the need to use plaster for this purpose is avoided. In accordance with the third illustrative embodiment, this is similar to the previous two examples, although the major difference is the springs, as shown in Figs. 17-22. The two spirally wound springs 206, each of which is attached to its own shaft end 273 and frame part 263, as indicated above, are so arranged as to lie essentially in alignment with the shaft 201 and with one another, in accordance with what is previously stated above, with the help of a clamping part 274 or a hook part 275 in holes 276, which permit rapid connection and disconnection of the parts should the need arise. The upper holder 207 is clamped securely to the frame with the help of pairs of uprights 277, which are accommodated in matching recesses 278 with good friction, and it is easy to pull out the holder and replace it once more in the correct position with the help of an upward-angled handle 279. The function of the invention should have been appreciated from the foregoing and with reference to the accompanying drawings . The invention is naturally not restricted to the embodiments described above and illustrated in the accompanying drawings. Modifications are possible, in particular with regard to the nature of the various parts, or by the use of equivalent technology, but without departing from the area of protection afforded to the invention, as defined in the Patent Claims.

Claims

Patent Claims

1. An arrangement (50; 150; 250) for an articulator

(51;151;251) for holding cast impressions of upper and lower sets of teeth in conjunction with the testing and processing of the same and comprising two holders (7, 11; 107, 111; 207, 211) capable of movement relative to one another, and each intended to hold its own cast impression of a set of teeth with a spring device (6; 106; 206) arranged between the aforementioned holders (7, 11; 107, 111; 207, 211) , characterized in that the spring device is so arranged as to permit the holders to move relative to one another respectively forwards (52; 152; 252) and backwards (53; 153; 253) from a neutral rest position (I; CI;CCI) for the holders .

2. Arrangement as claimed in Patent Claim 1, characterized in that one holder (7; 107; 207) is so arranged as to be capable of moving against the effect of the aforementioned spring device, and the other holder (11; 111; 211) is so arranged as to remain rigidly immovable.

3. Arrangement as claimed in Patent Claim 2, characterized in that the moving holder (7; 107; 207) is so arranged as to be guided along an essentially straight movement path (13; 113; 213) .

4. Arrangement as claimed in Patent Claim 3, characterized in that the aforementioned movement path (13;113;213) is inclined viewed from one of its ends.

5. Arrangement as claimed in one or other of Patent Claims 2-4, characterized in that the spring device is so arranged as to act on a transverse shaft (1; 101; 201), which supports the aforementioned upper holder (7; 107; 207) pivotally at both ends (56, 57; 156, 157; 256, 257) respectively.

6. Arrangement as claimed in Patent Claim 5, characterized in that the spring device is provided by a formed leaf spring (6), which supports the shaft (1) between both ends (6A,6B) of the leaf spring in an accommodating part (12) .

7. Arrangement as claimed in Patent Claim 6, characterized in that the shaft-accommodating part (12) is formed by a bent central part of the aforementioned spring (6) .

8. Arrangement as claimed in Patent Claim 5, characterized in that the spring device (106) is formed by a spirally wound spring preferably exhibiting a rectangular cross-sectional form, which is so arranged as to act at an angle to the shaft, essentially 90°, at both of the respective ends of the shaft, and in that the spring (106) is attached by its one end to the shaft (101) and is attached by its other end to the fixed holder (111), preferably by means of a spring eye (158) for accommodating the aforementioned shaft end and a fixing screw (159) .

9. Arrangement as claimed in Patent Claim 5, characterized in that the spring device is formed by a spirally wound spring, the central axis (260) of which extends essentially parallel to the pivot shaft (201) and is attached by its respective ends (261,262) to the shaft (201) and to a frame part (263).

10. Arrangement as claimed in Patent Claim 9, characterized in that one end (261) of the spring is passed onto the shaft (201) or is hooked onto the shaft and attached to it in such a way as to be incapable of rotating, while the other, opposite end (262) of the spring is attached to the frame part (263) in such a way that it is incapable of rotating or is free to rotate .