Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C11/00—Dental articulators, i.e. for simulating movement of the temporo-mandibular joints; Articulation forms or mouldings
  • A61C11/02—Dental articulators, i.e. for simulating movement of the temporo-mandibular joints; Articulation forms or mouldings characterised by the arrangement, location or type of the hinge means ; Articulators with pivots
  • A61C11/022—Dental articulators, i.e. for simulating movement of the temporo-mandibular joints; Articulation forms or mouldings characterised by the arrangement, location or type of the hinge means ; Articulators with pivots with two adjustable pivoting points, e.g. Argon-type articulators
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C11/00—Dental articulators, i.e. for simulating movement of the temporo-mandibular joints; Articulation forms or mouldings
  • A61C11/06—Dental articulators, i.e. for simulating movement of the temporo-mandibular joints; Articulation forms or mouldings with incisal guide
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C11/00—Dental articulators, i.e. for simulating movement of the temporo-mandibular joints; Articulation forms or mouldings
  • A61C11/08—Dental articulators, i.e. for simulating movement of the temporo-mandibular joints; Articulation forms or mouldings with means to secure dental casts to articulator
  • A61C11/088—Dental articulators, i.e. for simulating movement of the temporo-mandibular joints; Articulation forms or mouldings with means to secure dental casts to articulator using screws

Definitions

• the present invention relates to dental articulators and, more particularly, to an improved articulator which allows for accurate interchangeability of dental casts.
• the purpose of a dental articulator is to simulate the jaw or condylar movements of a patient.
• This instrument enables a dentist to obtain the necessary diagnostic information for the treatment of occlusal irregularities, such as malocclusion, and the fabrication of dental casts or "dentures".
• U.S. Patent No. 3,452,439 issued to Robert L. Lee on July 1, 1969, there is described a system of jaw movement simulation wherein the dynamic movement of a patient's jaws is recorded, and from this information plastic blocks are formed. These blocks have three-dimensional openings or pathways cut therein that may be used with a dental articulator to simulate or almost duplicate the particular patient's jaw movement..
• the dental articulator of the present invention eliminates the need for auxiliary equipment and insures that dental casts can be accurately transferred from one articulator to another with identical results obtained by merely mounting the cast on the mounting pad without adjustment.
• the lower frames of one type of articulator has an upwardly facing area for the mounting of the dental cast of the lower jaw or mandible of the patient.
• An upper frame of the articulator, disposed above the lower frame, has a similar area for mounting the dental cast of the uppe jaw of a patient's maxilla.
• the upper frame is supported by a portion of the lower frame which is vertical and which makes contact with the upper frame by means of a pair of spherical styluses.
• the styluses are mounted atop pedestals which are attached to the upper surface of a vertical portion of the lower frame, and the styluses are inserted into guide blocks supported on the rear of the upper frame.
• the dental casts can then be easily observed by moving the upper frame relative to the lower frame within the restraints allowed by the guide block- stylus joint.
• the mounting holes into which the guide block mounting pins are inserted must be maintained structurally consistent with the plane formed by the mounting area.
• a line through the center of the mounting hole should be parallel to the planes : formed by the mounting area of the upper frame.
• the relationship between the mounting area of the lower frame and the upper surface of the vertical portion of the lower frame is maintained parallel to a high degree of accuracy by machining those surfaces either simultaneous - or without moving the casting in a holding device.
• the machining is performed when the frame is a one-piece construction, preferably of a single casting. This construction is advantageous over articulators having separate lower and vertical frame portions which must be machined independently and then joined by fasteners or welding.
• the accurate relationship between the mounting area and the upper surface of the lower frame is also crucial in obtaining interchangeability among articulators which do not utilize the guide block-stylus type of hinging apparatus.
• the structural relationship between the mounting area of the upper frame and the centerline of the guide block mounting hole is also maintained parallel to a high degree of accuracy due to the machining and drilling of the surfaces to close tolerances. Again, the one-piece construction of the upper frame increases the accuracy of its construction.
• Another advantage of the present invention is found in the construction of the pedestals which support the styluses on the upper surface of the lower frame. It is imperative that the styluses be uniformly positioned on each articulator in order to insure interchangeability amon articulators. To achieve this, on the lower portion of eac pedestal is found a cylindrical sleeve which is mated to a ' close tolerance into a recessed area in the upper surface. This construction prohibits the pedestal from moving laterally with respect to the other pedestal, since a threaded attachment alone would not give a sufficiently rigid support to the pedestal.
• the sockets in the lower frame on which the pedestals are mounted are precisely spaced from each other and from alignment dowel holes formed in the dental cast mounting area of the lower frame. Also these holes are positioned accurately with respect to a centric locating slot.
• the upper frame is similarly provided with a precisely located hole for receiving a centric pin that mates with the slot in the lower frame.
• the upper frame is also provided with dowel holes in its dental cast mounting area that are accurately located with respect to the holes in the upper frame and with respect to end surfaces on the rear portion of the upper frame.
• Guide blocks mounted on the upper frame of the articulator each have an opening formed therein for receiving a stylus, and the rear wall and adjacent medial and upper wall portions of such opening is precisely formed to provide accuracy and interchangeability with respect to the hinge axis.
• Figure 2 is a perspective vie of one of the guide blocks showing the guide path
• Figure 3 is a side view of the lower frame with ' stylus and pedestal removed;
• Figure 4 is a side view of the upper frame with the guide blocks removed;
• Figure 4a is an enlarged, fragmentary view of the upper and lower frames illustrating hole alignments
• Figure 5 is a cross-section showing the construction of the pedestal and cylindrical sleeve portion
• Figure 6 is a perspective view depicting the manner in which the articulator of the present invention is tested for accuracy
• Figure 7 is a perspective view of a drill bit used for forming the rear wall of a guide block opening
• FIG 8 is an elevational, partially sectionalized view of a guide block with the drill in its operating position; and Figure 9 is an exploded, perspective view of a guide block and a curve plate which mounts on the guide block.
• a dental articulator having a lower frame 10 pivotally supporting an upper frame 12.
• the lower frame 10 includes a generally horizontal, T-shaped base member 14 having an extended arm 16 and a cross-bar portion 18. Extending vertically from the cross-bar 18 is a bridge-like portion 24. This vertical portion consists of two posts 24a and 24b, which are attached to the extreme ends of the cross bar, and a lateral truss 24c which connects the two posts to form a
• the vertical posts and lateral truss are an integral part of base member 14 and together form a one- piece construction.
• the extended arm 16 of the lower frame includes a mounting area 20 found on the upper surface of the arm for the attachment of a . ental cast, and an incisal pin rest pad 22.
• a mounting plate 21 is shown in phantom in Figure 1 on the mounting area 20, and in solid lines below the mounting area.
• a pair of alignment dowels 25 extend upwardly from the area 20, and mate with sockets in the upwardly extending pins 21a in the mounting plate 21. Additional buttons 21b on the mounting plate 21 facilitate the plaster connection to a dental cast.
• a threaded fastener 20a extends through a hole in the mounting surface 20 and threads into a socket in the lower side of the central button 21c in the mounting plate 21 to secure the plate to the area 20.
• a pair of column-like pedestals 28 which support spherical styluses 30.
• the pedestals rest on two raised surfaces or bosses 27 which are formed on the upper surface 26 of the vertical portion of the lower frame.
• the styluses 30 come into contact with guide blocks 32 and together act as a hinge in allowing upper frame 12 to move relative to lower frame 10 in simulating human jaw movement.
• a guide block 32 preferably constructed of plastic.
• a three-dimensional guide path 34 that controls the movement of the stylus 30 when received therein.
• the guide path 34 is provided by rear wall 34a, a medial wall 34b, a forward wall 34c, a lateral wall 34d, and an upper wall 34e.
• the rear and medial walls are joined by a curved corner 34f having a circular radius.
• Each guide block has a mounting pin 36 extending from the medial side of the block to
• OMPI allow for attachment of the blocks to the upper frame.
• a locking pin 37 extends through a hole in the lateral wall concentric with the pin 36. The inner end of the pin 37 is recessed to mate with a stylus 30 to enable the articulator frames to be locked together for simple hinging action.
• Set screw 39 fixes the pin 37.
• the upper frame 12 consists of a rear portion 38 and a forward portion 40 which extends out from the rear portion and is positioned above the extended arm 16 of the lower frame.
• mounting area 44 for receiving a dental cast, as shown in phantom in Figure 1.
• Extending vertically through the tip of the forward portion 40 is an in ⁇ isal rest pin 46 which rests in pad 22 on the lower frame in order to ' support the upper frame when no dental casts are mounted in the articulator.
• Rear portion 38 of the upper frame is a generally rectangular block having a transverse guide block ' mounting hole 42 extending from one vertical wall to the other.
• Guide block mounting hole 42 best seen in Figure 4, receives the mounting pins 36 of the guide blocks which are then locked into place by set screws 43.
• OMPI Referring to Figure 3, then, it is necessary to achieve a high degree of parallelism between boss 27 on which the pedestals rest, and mounting area 20.
• these surfaces are machined to be parallel simultaneously, or in sequence in a single machining procedure wherein the lower frame is mounted iri a holding fixture and a precision milling machine utilized to obtain the desired machining.
• the frame In addition to forming the surfaces 20 and 27 accurately parallel and spaced, it is also important that the frame have precision from front-to rear and from side to side.
• the center lines of the two dowel holes 25a should be accurately located with respect to the center line 48a of precisely located and drilled pedestal receiving sockets 48.
• these holes should preferably be formed while the one-piece frame is mounted in a single fixture or jig.
• a slot 84 in the lateral truss of the lower frame, shown in Figure 4a, should be accurately machined with respect to the holes 25a and 48.
• Slot 84 need not necessarily be centered, although this is preferable, but in any event it must be accurate to provide interchangeability between articulator frames.
• the dentist must move the upper frame relative to the lower frame in simulating the jaw movements of the patient. In doing so, the guide blocks bear against the styluses 30 according to the guide path 34, thus, creating moment forces on the pedestal 28.
• FIG. 5 shown in Figure 5, is a cross-section of the pedestal and a portion of the lateral truss 24c into which the pedestal is mounted. Beneath the shoulder 45 of the pedestal is a cylindrical sleeve 46 which snugly fits into the precisely located and drilled socket 48 in the upper surface 26 of the lateral truss. Beneath this ' sleeve are screw threads 50 which provide for attachment of the pedestal to the lateral truss.
• sleeve 46 Utilization of sleeve 46 insures the accurate spacing of the pedestals between each other and the maintenance of their rigidity, which has advantages a threaded attachment alone would not provide. That is, the threads serve only an attaching function rather than a locating function.
• hinge axis 31 be parallel to a close tolerance to mount area 44.
• the center line of guide block pin mounting hole 42 must be parallel to the mounting area 44. This is accomplished by making the upper frame as an integral unit and then machining the surface 44 and drilling the mounting hole in a coordinated operation to provide the necessary accuracy.
• the end surfaces.38a on the rear portion 38 are mach precisely parallel to each other, and the pin mounting hole is drilled through the rear portion 38.
• a snug fitting reference pin (not shown) is then positioned in the hole 42 with a portion extending outwardly to serve as a reference for the machining of the surface 44.
• the upper frame is then positioned in a fixture and the reference pin located in a cradle (not shown) on a milling machine, followed by the machining of the surface 44.
• the cradle is precisely located with respect to a reference surface on the fixture so that the surface 44 is precisely parallel
• the two dowel holes 40c in the mounting surface 44 be precisely located laterally with respect to the frame end surfaces 38a, and that they be precisely located from front to rear with respect to the center line 42a- of the pin mounting hole 42, as seen from Figures 4 and 4a.
• the center line 80 of a hole 82 must be precisely parallel to the end surfaces 38a and the dowel holes 40c.
• the hole 82 must also be accurately located (centered as shown) between the end surfaces 39a to align properly with the slot 84 in the lower frame, which was laterally centered.
• the center line 80 represents the center of both hole 82 and slot 84. It is preferable that these holes in the upper frame be performed while mounted in the same fixture to facilitate accuracy.
• a centric pin 86, Figure 1 fits precisely within the hole 82 and the slot 84 to lock the frames in centric position.
• the guide blocks 32 be accurately made and mounted.
• the mounting pin 36 is collinear with the center line of the locking pin 37.
• the hole in which the pin 37 extends should also be collinear and accurately formed.
• the rear wall 34a and adjacent portion of upper wall 34e in the guide block opening 34 must be accurately formed so that when the upper frame is in centric position with a stylus engaging the rear wall 34a and the • upper wall 34e, the center of the stylus will be precisely on the center line 47 through the mounting pin 36 and the locking pin 37, which of course also means the center line of the hole in the guide block through which the locking pin 37 extends.
• the guide block opening or pathway 34 may be made by machining or by molding techniques. However, it is difficult to mold plastic with precision, and difficult to machine the irregular opening 34 from above with accuracy. It has been found that the preferred and most accurate method for forming the rear wall 34a and adjacent -portions of upper wall 34e of the guide block 33 is that these surfaces be formed by the ' same drill bit or cutting tool used to form the hole through which the locking pin
• the tip 60a of the drill bit utilized is curved to provi the desired curvature of the corner 34f of the medial wall.
• the guide block outer medial surface 35 is used as a reference surface in controlling the depth at which the tool tip 68a is inserted during the cutting operation.
• the metal pin 36 provides rigidity to the plastic block which makes the surface 35 preferable to the outer lateral block wall as a reference surface. Thus, this critical area of the guide block can be accurately formed in a single drilling or precision lathe operation.
• a set of average value guide blocks be formed having different wall curvatures for the corner 34f. This is accomplished by utilizing a set of drill bits 60 having tips 60a which correspond to the desired curvature corners 34f.
• the tip curves are preferably circular segments having radii larger than the radius of the tool 60. However, other curves with a changing, but larger radii than the tool radius, might be desired in some instances.
• the diameter of the tool 60 and hence the hole formed thereby is equal to the diameter of the stylus 30, Figure 1, which moves within the guide block.
• the pin is formed with a very accurate cylindrical configuration which fits snugly within the hole thereby providing precise alignment.
• the pin is held in a desired position by a set screw 39 extending through a wall ' of the block, rather than utilizing threads or some other locking arrangement.
• the locking pin 37 is employed when it is desired to lock the frames in centric position for simple hinging action. When such action is not needed, the pin may be removed so as not to interfere with movement of the stylus within the guide block opening.
• a curve 90 corresponding to the curve of the upper or superior wall of the guide block may be formed on the outer or exterior wall of a guide block.
• a separate reference plate 70 shown in Figure 9.
• the plate is preferably made of light-weight plastic or metal and has a curve 72 formed thereon.
• the curve 72 corresponds or is parallel to the curve of the wall 34e within a particular guide block 32, when the plate is properly positioned on the exterior of the guide block.
• the plate 70 is provided with a short pin 74 on its back side which snugly fits within the hole 76 in the guide block through which the locking pin 37 is normally positioned.
• the pin 37 is withdrawn and the pin 74 of the plate 70 is positioned therein.
• a recess 78 is formed in the exterior wall corresponding to the shape of the plate 70 so that the plate 70 fits with the recess.
• An alignment pin 88 is precisely located in th recess 78 to mate with a corresponding precise hole 88a in the plate 70, so that the plate 70 is angularly oriented with respect to the curve of the upper wall 34e in the guide block.
• the curve 72 on the plate will accurately represent the path of the stylus 30 when moving in contact with the upper wall 34e in the guide block.
• the mounting pin 74 for the plate can be locked in position by the same set screw 39 utilized to clamp the locking pin 37.
• the mounting plate 21 is secured to the mounting area 20 by a suitable fastener 20a with the sockets in the pins 21a receiving the dowels 25 to insure accurate positioning.
• a dental cast is then secured to the plate 21 by plaster using known techniques.
• An upper dental cast is mounted on the upper frame in a similar manner using a mounting plate (not shown) similar to the plate 21.
• a hole is formed in the forward portion 40 of the upper frame 12 for receiving a threaded fastener 40a for connection to such a mounting plate.
• dowels 40b mate with holes in such a plate to accurately position the plate, as with plate 21.
• Figure 6 depicts the method in which the articulator of the present invention is tested for its accuracy.
• one way to achieve interchangeability on articulators is to construct each one so that the mounting area of the upper " frame is parallel to a high degree of accuracy to the mounting area of the lower frame, with a given spacing.
• a determination of this characteristic can be made by placing test blocks 52 onto the respective mounting areas of the upper and lower frames, and adjusting incisal pin 46 to the point where the mounting frames should be parallel.
• test blocks are formed with suitable accurately positioned sockets (not shown) similar to that in the buttons 21a on the mounting plate 21 to position the blocks transversely, and are also formed to receive the fasteners 20a and 40a for attaching the blocks to the frames, as is done with dental cast mounting plates, where the mounting frames should be parallel.
• a thin feeler gauge is then utilized to determine if there are any spaces between the test blocks whose mating surfaces should uniformly touch. If there are spaces or inconsistencies beyond the allowed tolerances, the articulator is not sufficiently accurate to allow interchangeability.
• the test blocks 52 are precisely formed on their sides so that the front to rear and side to side alignment can be checked by observation or feel. Also, vertical sight lines 53 may be scribed on the blocks to further assist in checking alignment.

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• Health & Medical Sciences (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Dentistry (AREA)
• Epidemiology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Dental Prosthetics (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=25509364

Family Applications (1)

Country Status (2)

Cited By (1)

Citations (8)

• 1979
  • 1979-11-26 JP JP50018379A patent/JPS55501129A/ja active Pending
  • 1979-11-26 WO PCT/US1979/001021 patent/WO1980001136A1/en unknown

Patent Citations (9)

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