Abstract:
A dental marking film holder holds articulating film in a patient&#39;s mouth, reducing the number of hands needed for the procedure. A pair of safety glasses worn by the patient includes a mounting point for affixing a mount to. In some embodiments, the mount is a clamp that attaches to the bridge of the glasses. In other embodiments, a mounting point on the glasses forms a ball-and-socket joint with the mount. The mount is connected to an articulating film holder by a flexible coupling. The flexible coupling provides for adapting to the geometry of an individual&#39;s face and for stably holding the articulating film holder at a range of positions. The articulating film holder accepts forceps that hold articulating film. In some embodiments, the articulating film includes disposable forceps. The articulating film holder adapts to a range of dental arch widths.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    The present application depends and claims priority from the Provisional Patent Application entitled DENTAL BITE MEASUREMENT FILM AND APPARATUS, serial No. 60/450,138, filed Feb. 25, 2003, invented by Dr. N. David Crow. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to a dental material and apparatus for bite determination, and more specifically to an apparatus for performing dental articulation.  
         BACKGROUND  
         [0003]    Dentists, orthodontists, and other professionals use dental marking films, or articulating films, to determine the bite characteristics of patients. By placing a piece of articulating film between the patient&#39;s teeth and moving the jaw through a range of movement, the film leaves an imprint on those areas of the teeth that come into contact with one another. Using such a technique, dentists are able to visualize the contact areas of the teeth and adjust the bite as may be desired.  
           [0004]    When skill and care are used to prevent wrinkling of the articulation film, it may also be possible to visualize contact by inspection of the film itself.  
           [0005]    It is frequently desirable for the dental professional to guide the patient&#39;s jaw through a range of motion. In such cases, the process of articulation may require additional personnel to assist in holding the articulating film in place.  
           [0006]    In other instances, it may be desirable to present the articulating film in a more precise or repeatable manner than is convenient or possible by hand.  
           [0007]    In other instances, articulation may be used in the preparation of dentures, braces, or other dental devices. It may be desirable to tune the bite of such apparatus prior to placement in the patient&#39;s mouth. In such cases, presenting the articulating film by hand may be impractical or undesirable.  
         OVERVIEW  
         [0008]    According to various embodiments and aspects of the present invention, an apparatus and method to aid in dental articulation, creation of prostheses, and other applications related to the determination of a patient&#39;s bite is taught.  
           [0009]    In one aspect according to the present invention, a dental bite determination apparatus reduces the effort on the part of the practitioner for the procedure. Such bite determination may be performed in a “hands-free” manner where the practitioner may rely on the apparatus to present and hold the articulating film, thus allowing the practitioner to perform other aspects of the procedure such as, for example, manually moving the patient&#39;s jaw through a range of motion with one hand while stabilizing the back of the patient&#39;s head with the other hand. The apparatus may further reduce the cost of labor by reducing or eliminating the need for an assistant to position and hold the articulating film while the practitioner performs other functions.  
           [0010]    In another aspect, patient comfort may be improved by gently guiding articulating film into the patient&#39;s mouth using the patient&#39;s cheeks as guide-ways. An articulating film is held by a smooth, non-metallic forceps that is adapted to being gently pressed against the patient&#39;s cheeks with minimal discomfort. A rounded tip on the forceps spreads the compressive load against the patient&#39;s cheeks, gums, and teeth to reduce the incidence of pain.  
           [0011]    In another aspect, a dental marking film includes features for easily and securely fitting it to a spreader. The spreader includes corresponding features for securely gripping the dental marking film.  
           [0012]    In another aspect, a dental bite determination apparatus and associated dental marking film have features for mounting the film in a plurality of orientations. In one orientation, one or two pieces of articulating film is presented longitudinally to measure the bite characteristics of the back teeth. In another orientation, the articulating film is presented laterally to measure the bite of the front teeth. Other embodiments allow various combinations of front and back teeth to be measured with single or plural articulating elements. Articulating elements may include conventional marking films of various types as well as sensing elements such as analog and digital sensors.  
           [0013]    In still another aspect, a dental marking film includes an integral handle or forceps amenable either to insertion into a hands-free apparatus or being hand-held. The inclusion of an integral forceps with the dental marking film further makes it cleaner and easier to use.  
           [0014]    In another aspect, a dental bite determination apparatus includes features for easy and reliable insertion into a patient&#39;s mouth. A forceps attached to the edge of a marking film itself, is laterally pressed against the inside of a patient&#39;s cheek by the spreader, thus holding a marking film in a proper orientation between the upper and lower teeth. As the forceps is slid posteriorly, it is gently guided by the cheek. The proper insertion depth is determined by pressure of the end of the forceps against the patient&#39;s jaw. The forceps holder may provide spring action to gently hold the forceps in an appropriate orientation and with appropriate pressure. Alternatively, a friction clamp provides appropriate resistance to medial movement to ensure the forceps are gently engaged laterally against the patient&#39;s cheeks.  
           [0015]    In another aspect, a dental bite determination apparatus includes a spreader that holds the width of a pair of forceps holding articulating film by use of a friction fitting. The friction fitting allows insertion of the articulating film in a closed position, wherein both forceps are held near the center of the patient&#39;s mouth. The practitioner may then spread the forceps to an appropriate width that positions the articulating film over the patient&#39;s dental arches using finger pressure. In some embodiments, a frictional holding power of approximately 3 inch-ounces has been found to provide satisfactory performance.  
           [0016]    In another aspect, a digital bite pressure apparatus includes a spreader having a variable width accommodation. One or a pair of forceps holding articulating film are coupled to the spreader. The spreader may include a fork fitting that releasably couples to the distal end of a holder rod. The fork allows the spreader to rotate in both a horizontal and a vertical plane and slide up and down the connector rod to adapt to the size and shape of patients&#39; heads and mouths. The holder rod includes a socket joint on its proximal end, the socket joint being adapted to reversibly couple to a corresponding ball joint mounted on the end of a nose post. The nose post is affixed or formed integrally to the bridge of a pair of safety glasses. The patient is fitted with the safety glasses having the nose post thereon. The socket joint is connected to the ball joint on the end of the nose post, thus forming a universal joint that allows the connector rod to rotate. The freedom or ease of rotation may be adjusted by tightening or loosening the threaded end of the connector rod in the socket joint, thus pressing more tightly or more loosely, respectively, against the ball joint. The universal joint and fork joint are then adjusted to admit the distal end of the forceps and articulating film into the patient&#39;s mouth. The width of the spreaders may be easily adjusted to accommodate the width of a variety of dental arches. Once placed, the assembly is held securely enough to allow the practitioner to let go of the forceps and/or spreader and use both hands to perform other aspects of articulation.  
           [0017]    In another aspect, patient safety glasses provide a secure and convenient mounting point for a variety of dental and medical apparatus. In particular applications, a mechanical mounting point or coupling may be mounted on or formed integrally to the glasses. A corresponding mount may be removably attached thereto, the corresponding mount, in turn, being coupled to a mechanical coupling or holder arm that attaches to a spreader. The mechanical coupling or holder arm allows for convenient positioning of the spreader and retains its position and angle once set, until the practitioner repositions the spreader. The spreader includes provision for accepting articulating film forceps, which in turn hold the articulating film itself. The spreader includes provision for adjusting the angle of the forceps to match the width of the dental arches of the patient.  
           [0018]    In various embodiments, the adjustable holder arm may be formed proximally or distally to the mounting point and separable mount, relative to the patient. In some embodiments an adjustable holder arm may be integrated with the mounting point, thus making the position of the mounting point itself adjustable. Thus, the adjustable arm is attached, for example, to a pair of safety glasses and has a mounting point on its distal end for accepting the spreader.  
           [0019]    In other embodiments according to the invention, the mounting point may be established in a particular position in space, with the adjustable holder arm being placed distally relative to the mounting point. Thus, the mounting point is attached, for example, to a pair of safety glasses, the mounting point accepting the proximal end of the adjustable arm.  
           [0020]    In another aspect according to the invention, an adjustable dental marking film holder is amenable to testing of molds of a patient&#39;s teeth, dentures or other appliances outside the patient&#39;s mouth. A fitting holds the appliance and/or mold of the patient&#39;s teeth in an appropriate orientation, a mount allows for coupling a post, which in turn accepts a spreader for positioning a marking film in the bite region of the appliance to be tested. Articulation may be performed in a manner similar to that of live articulation on the patient. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    [0021]FIG. 1 is an isometric view of a marking film holder apparatus having a compound holder arm and an operative position on safety glasses worn by a dental patient.  
         [0022]    [0022]FIG. 2 is an enlarged isometric view of the marking film holder of FIG. 1, showing an embodiment where an articulating joint is located in the holder arm.  
         [0023]    [0023]FIG. 3 is an enlarged partial side-sectional view through the interconnection of the glasses fastening body and the holder arm, taken on the line  3 - 3  on FIG. 2.  
         [0024]    [0024]FIG. 4 is an enlarged cross-sectional view through the glasses fastening body of the holder, taken on line  4 - 4  on FIG. 2.  
         [0025]    [0025]FIG. 5 is an enlarged cross-sectional view through the joint interconnecting the upper and lower portions of the holder arm, taken on the plane  5 - 5  on FIG. 2.  
         [0026]    The FIG. 6 is a side-sectional view through the interconnection of the holder arm and the spreader, taken on the plane  6 - 6  on FIG. 2.  
         [0027]    [0027]FIG. 7 is an enlarged partial rear orthographic view of the spreader with forceps accepting slots in the closed (medial) position.  
         [0028]    [0028]FIG. 8 is an isometric view of protective eyeglasses usable support the marking film holder.  
         [0029]    [0029]FIG. 9 is an isometric view of a marking film and forceps assembly.  
         [0030]    [0030]FIG. 10 is a side-sectional view through the forceps and marking film assembly of FIG. 9, taken on the line  10   −10.    
         [0031]    [0031]FIG. 11 is a cross-sectional view through the marking film and forceps assembly of FIG. 9, taken on the line  11 - 11 .  
         [0032]    [0032]FIG. 12 is an isometric view of a marking film holder having a universal joint and L-shaped holder arm.  
         [0033]    [0033]FIG. 13 is an enlarged isometric view of the marking film holder of FIG. 12.  
         [0034]    [0034]FIG. 14 is a partial enlarged side-sectional view through the universal joint (also referred to as the mount and mounting point, and alternatively as the fastening body) of the marking film holder of FIG. 13, taken on the line  14 - 14 .  
         [0035]    [0035]FIG. 15 is an isometric view of an alternative holder arm that is plastically formable.  
         [0036]    [0036]FIG. 16 is a partial side-sectional view through the fastening body of the marking film holder of FIG. 15, taken on a line  16 - 16 .  
         [0037]    [0037]FIG. 17 is a cross-sectional view of the marking film holder arm shown in FIGS.  18 - 20 , taken through the ball-and-socket joint formed between the mount  20   c  and mounting point  74 , the mounting point being formed on the bridge of a pair of safety glasses.  
         [0038]    [0038]FIG. 18 is a perspective view of a dental marking film holder being inserted into the mouth of a patient. FIG. 18 further illustrates an embodiment of the nose post and holder arm that are coupled through a universal joint.  
         [0039]    [0039]FIG. 19 is a perspective view of an apparatus for hands-free support of a dental marking film as worn by a patient. FIG. 19 illustrates a first marking film position for measuring the bite of a patient&#39;s rear teeth. It further illustrates the ability of the practitioner to operate the apparatus in a “hands-free” manner, instead using both hands to move the patient&#39;s jaw through a range of motion.  
         [0040]    [0040]FIG. 20 is a perspective view of a dental marking film holder as worn by a patient illustrating an alternative marking film orientation for measuring the bite of the front teeth, and particularly for harmonizing the anterior guidance.  
         [0041]    [0041]FIG. 21 is an isometric view of a dental marking film having integral forceps with registration features.  
         [0042]    [0042]FIG. 22 is a side-sectional view of a dental marking film having integral forceps with registration features.  
         [0043]    [0043]FIG. 23 is a side-sectional view of a spreader clamped onto the forceps of FIGS. 21 and 22.  
         [0044]    [0044]FIG. 24 is an isometric view of a dental marking film having forceps with alternative registration features.  
         [0045]    [0045]FIG. 25 is an isometric view of a dental marking film having forceps with other alternative registration features.  
         [0046]    [0046]FIG. 26 is a plan view of an adaptor for inserting alternative marking film forceps into a spreader.  
         [0047]    [0047]FIG. 27A is a top view of an alternative dental marking film forceps.  
         [0048]    [0048]FIG. 27B is a side view of the alternative dental marking film forceps of FIG. 27A.  
         [0049]    [0049]FIG. 27C is a detail top view of the alternative dental marking film forceps of FIGS. 27A and 27B showing the latch mechanism. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0050]    The marking film holder of FIG. 1 generally provides nose post  20  mounted to safety glasses  19  and carrying holder arm  21 . Spreader  22  is coupled to holder arm  21 . Marking film and forceps assemblies  23  are mounted in the spreader and are positioned in a laterally spread configuration. Nose post  20  is alternatively called a glasses fastening body. Holder arm  21  is alternatively called a holder rod or coupling or adjustable arm.  
         [0051]    Safety glasses  19 , also illustrated by FIG. 8, are one type of head mounting apparatus that may be used to support the marking film holder. The safety glasses  19  may be a commercially available type used for eye protection for dental patients. The safety glasses have laterally opposed, rearwardly extending ear bows  24  for support on the patient&#39;s ears. The ear bows  24  are interconnected at their forward ends by face bow  25  having medial nose bridge  26  and carrying a protective lens  27  on each side of the nose bridge  26 . One attribute for such safety glasses is that they provide a nose bridge  26  that allows attachment of the nose post  20 . Thus, the glasses form a structure that allows for mounting the occlusal marking system in a location that is substantially constant relative to the patient&#39;s mouth.  
         [0052]    As an alternative to fastening the occlusal marking system to the nose bridge of a pair of safety glasses, other mounting points may be used according to the preference of the designer and practitioner. For example, a Y-shaped support may extend forward from the corners of the face bow where it joins the ear bows. Alternatively, a hat, helmet, or other secure head mount may be used.  
         [0053]    The nose post, or glasses fastening body,  20  as seen in FIGS.  1 - 7 , and in section in FIGS. 3 and 4, includes a clamp comprising body  28  and legs  29  that together form the clamp structure. Cavity  30  extends into the clamp to accept holder arm fastening pin  31 . Bolt  32  extends through holes  33  perpendicular to legs  29  to engage knurled nut  32   a . Tightening or loosening the knurled nut  32   a  moves legs  29  relative to one other and regulates the amount of frictional contact between the holder arm fastening pin  31  and cavity  30 .  
         [0054]    Bolt  34  passes through hole  35  defined in the nose bridge  26  of the safety glasses  19  to engage threaded hole  36  defined in the clamp body  28 , thus securing the nose post  20  to the safety glasses.  
         [0055]    As an alternative to a bolted-on nose post, the safety glasses may be molded with an integral nose post. Alternatively, a spring clamp, screw clamp, or similar removable structure may be used to attach the nose post to a pair of safety glasses that do not have a hole formed in their nose bridge.  
         [0056]    Referring especially in FIG. 4, holding arm fastening pin  31  is held in cavity  30  by the legs of staple  38  extending through clamp body  28  and into annular groove  39  defined in fastening pin  31 . The forward portion of holding arm fastening pin  31  defines threaded hole  40  to receive bolt  41  extending through hole  42  in the upper portion of holder arm  21  to fasten the holder arm to nose post  20 .  
         [0057]    As seen particularly in FIGS. 2 and 5, holder arm  21  includes two fittings, each allowing rotation in one plane. As described above, the upper end allows rotation in a vertical lateral plane by the rotation of holder arm fastening pin  31  in cavity  30 . A second fitting allows rotation of the lower portion  44  of holder arm  21  in a vertical anterior plane, relative to the upper holder arm portion  43 . A bolt  46  and knurled nut  49  control the frictional resistance of the lower fitting in a manner similar to that of bolt  32  and knurled nut  32   a  of the upper fitting.  
         [0058]    Spreader  22 , as seen in FIGS.  1 - 2 ,  6 - 7 ,  12 - 13 , and  18 - 20 , includes body  50  defining vertical slot  51  extending through its forward portion and horizontal slot  52  extending through its rearward portion. The forward vertical slot  51  is configured as a fork fitting to receive the lower portion of holder arm  21  in a friction fit. As will be described later, the fork allows the spreader  22  to be quickly coupled to and uncoupled from holder arm  21  using fingertip pressure, while maintaining its position once established.  
         [0059]    Rear horizontal slot  52 , in the instance illustrated in FIGS. 6 and 7, carries two marking film mounting arms  53  and  54 . Each mounting arm  53 ,  54  defines a holding element  55  (referred to elsewhere as holding element portions  55   a  and  55   b ), which in turn, defines a forceps receiving channel  56  therein. Forceps receiving channels  56  receive and hold the holding portion of a marking film and forceps assembly  23 . The upper portions  55   a  and lower portions  55   b  of holding elements  55  extend from the rearward mouth of channel  56  to aid positioning of the holding portions marking film structures in channel  56 . Additionally, the flanges formed by upper and lower portions of holding elements  55  allow a forceps to be inserted and held in a lateral position, as shown in FIG. 20.  
         [0060]    Forward portions of each holding element  55  define perpendicularly extending fastening portions  57  that are carried in rear horizontal slot  52 . The paired fastening portions  57  of each mounting arm  53 ,  54  are offset vertically relative to each other, as shown in FIG. 7, to maintain the channels  56  of both holding elements  55  in substantially the same horizontal plane to aid simultaneous tooth marking on both lateral aspects of the dental arches.  
         [0061]    Each fastening portion  57  defines vertically oriented axially aligned holes  58  to bolt  59  therethrough for fastening by knurled nut  60 . Bolt  59  extends through axially aligned holes  64  defined through body  50  in a position and axially coextensive with holes  58  in fastening portions  57  and engages knurled nut  60  on the opposite side the body By adjusting the tightness of knurled nut  60  on bolt  59 , the friction against the fastening portions  57  of mounting arms  53  and  54  within slot  52  may be adjusted according to the preference of the designer and user. The frictional force resists pivotal motion of the two holding elements  55  relative to each other and to body  50 . In some applications, it has been found that approximately 3 inch-ounces of frictional resistance works well for making movement of the spreader relatively easy while also maintaining a position once set.  
         [0062]    In alternative embodiments, body  50  may be constructed with a single rearward-extending horizontal tab that includes a single hole  64  formed therethrough. In this configuration, fastening portions  57  of holding elements  55  may be offset to extend respectively above and below the single tab, while maintaining horizontal alignment of the forceps receiving channels. Bolt  59  may be replaced by a threaded shaft. Each end of the threaded shaft may be engaged by a respective wing nut to facilitate convenient and fast adjustment of the frictional resistance.  
         [0063]    In some embodiments, it has been found advantageous to construct the body  50  integrally with the fork fitting of a relatively soft plastic material such as nylon or high density polypropylene, for example. The wing nuts are constructed of a similar material. The threaded shaft is formed from stainless steel, such as #304 stainless steel. Holding elements  55  are formed from an anodized aluminum. The resultant altering layers of plastic and hard materials in the width-adjustment mechanism of the spreader provide a forgiving and easily adjustable fit having a smooth transition from low to high frictional resistance. The relatively soft material of the fork fitting similarly provides a gentle and forgiving, yet secure coupling to the holder arm.  
         [0064]    Marking film assembly  23 , as seen especially in FIGS.  9 - 11  with marking film  62  engaged by the forceps  61 , provide a relatively rigid body  61  having film holding portion  202  and handle fastening portion  204 . The forceps  61  is formed from pieces of rigid or semi-rigid polymeric or paper material with a strip of dental marking film  62  sandwiched therebetween and extending laterally therefrom. The marking film assembly  23  generally, but not necessarily, is designed for single use applications, and if so, dental marking film  62  is joined to the adjacent portions of forceps  61  by a permanent joinder process such as gluing, fusing, crimping, or adhering, for example. In some applications, the portions of one or both sides of forceps  61  adjacent to the marking film are formed with protuberances that extending through the marking film and into indentations or holes in the opposite back portion. Alternatively, opposed sides of the back are joined by thermal welding processes or adhesion.  
         [0065]    An alternative, reusable forceps is illustrated by FIGS. 27A, 27B, and  27 C.  
         [0066]    The handle portion  204  of forceps  61  is configured to fit within channel  56  of holding elements  55  in a frictional fit that is positionally sustaining but yet allows manual manipulation for insertion and removal. Fit between the forceps and holding elements  55  may be aided by forming one or more registration features on one or more surfaces of handle fastening portion  204  and/or the adjacent inner surfaces of holding elements  55  defining channel  56 .  
         [0067]    Some exemplary forceps registration features are illustrated by FIGS.  21 - 25 .  
         [0068]    Marking film  62  may be of the ordinary type commercially available. This marking film generally comprises a relatively thin flexible film of polymeric material or metallic foil, normally ranging in thickness from about 5 to 20 microns (0.0002 to 0.0008 in.) for proper marking. The marking film is of substantially rectilinear configuration with a length parallel to the longer dimension of forceps  61  of approximately 2.75 inches and a width perpendicular to the length of approximately 1 inch. Various sizes of forceps and marking film may be used to adapt to patients. One or both sides of the marking film are coated with transferable dye material that may be imprinted on tooth surfaces coming into contact therewith, especially when such contact has some slight impact or pressure. Commonly, if two-sided marking films are used, the colored marking dies on each surface are different in color from each other to avoid confusion in analyzing marks on patients&#39; teeth.  
         [0069]    Another type of marking film holder having a unitary holding arm  21   a  and universal joint  20   a  is shown in FIGS.  12 - 17 . In the embodiment shown in FIGS. 13 and 14, a short nose post  65  is attached to glasses nose bridge  26  with a fastening screw  34 . The end of nose post  65  forms a ball  66 . A mating socket  68  is formed by walls  70  extending from the fitting  67 . The fitting  67  is coupled to the end of the holder arm  21   a . When coupled, the ball-and-socket  66  and  68  forms a universal joint having a frictional fit that allows the holder arm  21   a  to be rotated at least in vertical lateral and vertical anterior planes and maintain its position. Thus, the single fitting  20   a  provides sufficient degrees of freedom to position the holder arm. As described earlier, fork fitting  51  may be conveniently attached and detached at various distances and at various angles to the holder arm  21   a . Thus, the fork fitting provides additional degrees of freedom that allow the marking film holder to be quickly adapted to a range of patients.  
         [0070]    Appropriate friction in the ball joint may be obtained by forming the interconnected elements from resiliently deformable materials that have a retentive memory such as plastics, for example nylon or high density polypropylene.  
         [0071]    The holder arm  21   a  may be formed of a rigid material that need not change its shape for use, such as a plastic or metal material. In one application, it was found to be advantageous to form the ball  66  from anodized aluminum, the socket fitting  67  from a plastic material, and the holder arm  21   a  of an anodized aluminum. The holder arm is threaded into a hole formed in the socket body and may be engaged against the ball  66  with a force proportional to how far it is turned.  
         [0072]    As depicted by FIG. 17, the nose post  65  was extended approximately an inch forward and downward from the glasses nose bridge. With the ball joint in this position, the holder arm was made straight and still cleared the tip of the patient&#39;s nose. Thus, the holder arm may be threaded into and out of the socket portion  67  of the universal joint without a bend in the holder arm causing misalignment of the bottom of the holder arm.  
         [0073]    The film holder of FIGS. 15 and 16 uses a universal joint similar to that of FIGS. 13 and 14. In this case, the socket joint body  67   b  is somewhat longer and defines a downwardly and forwardly angulating hole  69   b  to receive the upper end of holder arm  21   b.    
         [0074]    As an alternative or in addition to a universal joint, the holder arm may be formed of a material that is plastically deformable with less retentive memory than described earlier. In this configuration, the holder arm  21   b  may be manually configured and thereafter will substantially retain a shape once established unless and until it is manually reconfigured. Various plastics having this physical characteristic are known and available.  
         [0075]    Returning to FIG. 17, a forwardly in downwardly angulated nose post or mounting arm  74  extends from the nose bridge  26  of safety glasses  19  to a ball joint  66 . FIG. 17 is a side-sectional view of this structure joined to socket fitting  20   a , which is coupled to holder arm  21   c.    
         [0076]    The rearward portion of mounting arm  74  is fastened on the forward surface of nose bridge support  26  by bolt  34  extending through hole  35  defined in the nose bridge support and into engagement with the threads of hole  76  defined in mounting arm  74 . The lower vertical surface  77  of the mounting arm  74  carries universal joint  20   c , which is substantially the same as the universal joint  20   a  described above. Fastening portion  65  of universal joint  20   c  is structurally interconnected to the mounting arm  74  by bolt  78  extending through hole  79  defined in the mounting arm and into threaded engagement with fastening portion  65 . The ball  66  carries socket body  67 , which in turn carries vertically depending holder arm  21   c . Holder arm  21   c  may be substantially the same as the fastening rods  21   a  or  21   b  and may be a vertically depending linear fastening rod of either rigid or manually moldable nature. The forwardly and downwardly angulated mounting arm  74  allows the holder arm  21   c  to clear the nose of the patient.  
         [0077]    [0077]FIGS. 18, 19, and  20  are perspective views that illustrate use of the occlusal marking system. Safety glasses  19 , worn by the patient, support nose post  20 , to which holder arm  21  is connected via a universal joint. FIG. 18 illustrates a preferred technique for inserting the marking film. The practitioner holds the spreader  22  with the forceps  61   a  and  61   b  straight, and inserts the forceps and marking film assemblies into the patient&#39;s mouth. After insertion, the spreader is opened using the thumbs and forefingers of both hands to a width appropriate for the width of the patient&#39;s dental arches.  
         [0078]    After insertion of the marking films into the patient&#39;s mouth, the practitioner may rotate connecting rod  21  to an appropriate position and clip spreader  22  thereto. The connecting rod  21  is coupled to the spreader fork by holding the spreader with one hand and pushing the rod into the fork with the index finger. Correct placement of the marking films may be quickly visualized. The patient is now ready for bi-manual manipulation or other mandibular movement.  
         [0079]    Connecting rod  21  may be adjusted for frictional characteristics against the nose post  20  by a setscrew, spring, elastic properties, surface treatment, or other known methods.  
         [0080]    [0080]FIG. 19 illustrates this position, wherein spreader  22  gently holds forceps  61   a  and  61   b  laterally against the patient&#39;s cheeks, a position that maintains proper alignment of marking films  62   a  and  62   b  with the patient&#39;s teeth. Anterior-posterior as well as medial-lateral alignment of the film holder  22 , and hence the marking films  62   a  and  62   b , is maintained by the position of connecting rod  21 .  
         [0081]    To remove the occlusal marking system, the thumb is place on the fork of the spreader and pinched to lift the rod with the forefinger. The freed connecting rod is rotated to one side. The spreader is closed and removed. The operator can see interferences marked on the films or on the teeth. In contrast to prior art, which may for example use hand-held Miller forceps, it is easy to keep the marking ribbons straight and dry. As an alternative, the forceps described herein may also be hand-held as may be desired.  
         [0082]    [0082]FIG. 20 illustrates an alternative position for holding a marking film structure  23  in a patient&#39;s mouth. The position illustrated in FIG. 20 is especially appropriate for testing the bite of a patient&#39;s front teeth and may be used to harmonize the anterior guidance. Spreader  22  is clamped onto two locations on forceps  61 , thus holding it in a laterally extensive position to hold marking film  62  in the proper position between the patient&#39;s front teeth.  
         [0083]    Marking film assembly  23  may be comprised of a marking film  62  adhered permanently to forceps  61 . As an alternative to use of film holder  22 , marking film assembly  23  may be manually inserted and held in the patient&#39;s mouth by a practitioner or assistant directly gripping extended end  204  of forceps  61 . Thus, marking film assembly  23  may comprise a disposable unit that eliminates the need for cleaning forceps or tediously inserting marking film  62  into forceps. Such a product may be individually or multiply packaged according to user or seller preference.  
         [0084]    [0084]FIGS. 21 and 22 illustrate a first alternative forceps design that includes features for maintaining coupling stability with the film holder. Registration feature  2102   a , here illustrated as a hole, provides a feature into which a corresponding pin in film holder  22  may be inserted. The use of such a registration feature not only aids in the rigidity of the structure, it also ensures that marking film structure  23  is withdrawn from the patient&#39;s mouth when film holder  22  is pulled anteriorly out of the patient&#39;s mouth. Optional registration features  2102   b  and  2102   c , here illustrated as holes, provide similar positive interlocking of the film holder  22  and marking film structure  23  in the laterally extensive position of FIG. 20.  
         [0085]    Additionally FIGS. 21 and 22 illustrate the blunt tip  2104  of forceps  61 . As previously described, this blunt tip can aid in placement and registration of marking film structure  23  against the vertical extension of the patient&#39;s jaw bone. Making tip  204  blunt, rounded, and smooth may help to maximize patient comfort. In another aspect, patient comfort may be maximized by forming forceps  61  from a material that is relatively smooth and non-abrasive. Additionally or alternatively, the material may be chosen based on a low thermal conductivity and/or relative softness. These properties can improve the sensation of sliding against the cheek as well as reduce the rudeness of unintended collision with the patient&#39;s teeth.  
         [0086]    Extended end  204  of forceps  61  may alternatively comprise features such as dimples, a tab, or other to improve the ergonomics of manually holding the marking film assembly  23  and/or inserting marking film assembly  23  into the forceps channels  56  of spreader  22 .  
         [0087]    [0087]FIG. 23 illustrates a method for mating the forceps of FIGS. 21 and 22 with a film holder  22 . Here, extending portion  204  (see FIG. 22) of forceps  61  is inserted into film holder  22 , all parts shown in cross-section. Moveable clamp  2302  includes pin  2304  sized to fit into registration hole  2102   a . Ideally, pin  2304  is sized to easily slide into registration hole  2102   a  without interference sufficient to cause the pin to “hang-up” during extraction. Moveable clamp  2302  may be formed, for instance, from an elastic material that allows the far end of moveable clamp  2302  (not shown) to be held in a fixed position, the swinging of moveable clamp  2302  being accomplished by elastic deformation of the part itself. Anvil  2306  forms a bottom support for forceps  61  with stop  2308  defining the allowable insertion depth of forceps  61 . Moveable clamp  2302  may optionally include tab  2310  to aid the ease of gripping moveable clamp  2302  during insertion and extraction of forceps  61  from film holder  22 .  
         [0088]    [0088]FIG. 24 illustrates a marking film  23  having an alternative registration feature  2102   a  formed in the extended end  204  of forceps  61 . In this case, registration feature  2402   a  is formed as a notch in extended end  204  of forceps  61 . Optionally, location features  2402   b  and/or  2402   c  may additionally be formed as notches at appropriate positions along forceps  61 .  
         [0089]    [0089]FIG. 25 illustrates a marking film  23  having another alternative registration feature  2102   a . In this case, registration feature  2402   a  is formed as a groove in extended end  204  of forceps  61 . In this case, a corresponding ridge would be formed in the forceps channels  56  of film holder  22  (not shown). In other embodiments the size and shape of the holding portion  204  itself of forceps  23  may serve as a registration feature. Thus a friction, spring, or interference fit of a smooth holding portion against the forceps accepting features of spreader  22  may serve to register and securely hold the forceps. In one embodiment, this is achieved by specifying the holding portion  204  of forceps  23  to be 0.25 inch wide by about 0.07 inch thick.  
         [0090]    [0090]FIG. 26 illustrates an adaptor  2602  for adapting forceps to a film holder having registration features. In this case, forceps  61  need not have registration features, or alternatively may have different registration features than film holder  22 . This arrangement could allow, for instance, one manufacturer&#39;s forceps to be used with another manufacturer&#39;s film holder. In this case, adapter  2602  includes a slot  2604  formed to accept alternative forceps  61 . Adaptor  2602  is shown having a registration feature  2402   a  comprising a hole similar to the embodiment of FIGS. 21 and 22. Adaptor  2602  may, for instance, be formed of a soft elastic material such as silicone rubber or polyurethane to facilitate insertion and gripping of alternative forceps  61 .  
         [0091]    [0091]FIGS. 27A and 27B are respective top and side views of an alternative dental marking film forceps  23 . A relatively rigid and elongate back portion  2702  forms a frame for holding the marking film (not shown). Back portion  2702  may, for example, be formed from 0.040 inch thick flat stock #304 stainless steel. The proximal end of back  2702 , which in this example is formed 0.25 inch wide, forms a holding portion  204  that is adapted to be accepted by the acceptor cavity  56  shown in FIG. 7, formed from structure  55  shown especially in FIGS. 2, 7, and  13 . A clamp portion  2704 , seen especially in FIG. 27 b , is formed from 0.030 inch thick spring stock #304 stainless steel and is permanently affixed to back portion  2702  at the proximal end by spot weld  2706 .  
         [0092]    In one embodiment, alternative forceps  23  tapers from approximately 0.25 inch wide at its proximal end to approximately 0.1875 inch wide at its distal end and includes a rounded distal end to avoid gouging the patient. The length of the example shown in FIGS.  27 A-C is approximately 3.375 inches, although this may be varied according to the preferences of the practitioner and the depth of a patient&#39;s dental arches. A variety of sizes may be kept on-hand to adapt to patients.  
         [0093]    As may be appreciated from inspection of FIGS. 27A and 27B, clamp  2704  is separable from back  2702  to allow a piece of dental marking film to be placed therebetween. The distal end of alternative forceps  23  includes a latch  2708  for pinching the back and clamp portions together to hold dental marking film. FIG. 27C illustrates the latch mechanism in the open position.  
         [0094]    Latch  2708  is rotatably coupled to back  2702  by a rivet  2710 . A detent  2712  formed on the lip of latch  2708  for engagement of a corresponding detent  2714  formed on clamp  2704 . Engagement of detent features  2712  and  2714  holds clamp  2708  shut, thereby ensuring that clamp  2704  is held tightly enough against back  2702  to secure a piece of dental marking film therebetween.  
         [0095]    In the clinical setting, alternative articulating film forceps  23  may be cleaned and/or sterilized between patients. A technician or dentist places a piece of dental marking film between back  2702  and clamp  2704  and secures the clamp and back together by rotating latch  2708  to engage detents  2712  and  2714 . After use, the technician or practitioner rotates latch  2708  into an open position corresponding to FIG. 27C, springably releasing clamp  2704  from back  2702 , and releasing the articulating film therefrom. The procedure may then be repeated for the next patient or the forceps may be immediately used in a different position on the same patient.  
         [0096]    Although the alternative forceps  23  shown in FIGS. 27A, 27B, and  27 B is shown with a particular choice of materials, joining and latching mechanisms, and dimensions, alternatives may be employed as would be apparent to one skilled in the art. For example, the material may be formed from a plastic, alternative metal, paper, wood, or other material depending upon economic, performance, and safety considerations. The clamp and back portions may be joined via a variety of known fastening methods, including but not limited to integral forming, molding, gluing, screwing, crimping, and other methods. The latch mechanism may be altered or placed on the proximal end. The holding portion  204  may be altered according to the shape of the forceps accepting channels and/or may be extended to facilitate hand-held use.  
         [0097]    If constructed of the materials shown, a micro break press may be used to form certain features. The edges of the material are optimally radiused to ensure patient and practitioner comfort and safety.  
         [0098]    The preceding overview of the invention, brief description of the drawings, and detailed description describe exemplary embodiments of the present invention in a manner intended to foster ease of understanding by the reader. Other structures, methods, and equivalents may be within the scope of the invention. As such, the scope of the invention described herein shall be limited only by the claims.