Abstract:
An intraoral dental mirror includes an elongated handle and a light guide that is releasably attached to a distal end of the handle. The light guide includes a mirrored portion that has a non-plano reflective surface that is configured to either magnify the image or to widen the field of view thereof as opposed to a flat or piano mirrored surface.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to the field of medical and dental diagnostic instruments, and more particularly to an illuminated dental intraoral instrument having a disposable mirror that includes an improved imaging surface.  
       BACKGROUND OF THE INVENTION  
       [0002]     Intraoral dental mirrors, such as those described for example, in U.S. Pat. No. 6,574,744B1 to Oshida et al., and U.S. Pat. No. 5,741,132 to Usui et al., are widely used in the field for examination of the teeth and other oral cavity structures. These mirrors typically include an elongated handle having a retroflexed reflective surface that is formed at a distal end of the handle. The handle portion of the instrument can accommodate at least one battery for powering a light source which is provided within the mirror portion of the instrument.  
         [0003]     Other versions, such as those that are described in U.S. Pat. Nos. 5,139,421 and 5,457,611, each to Verberder et al., include a miniature light source, such as a halogen or other incandescent bulb or lamp, that is contained in a distal end of the elongated handle. A shank, interconnecting the mirror head with the elongated handle, includes a series of light pipes therewithin that transmit the light from the contained halogen bulb to the front and back of the mirror head. Alternatively, the light guide can be constructed from a light transmissive material that is releasably attached by means of a collet to the distal end of the elongated handle.  
         [0004]     Though the above mirrored instrument is highly effective in examining the teeth and other oral structures of the patient, there is a general need in the field to improve the overall efficacy of examinations using the above instruments.  
       SUMMARY OF THE INVENTION  
       [0005]     It is therefore a primary object of the present invention to meet the above-noted general need in the field.  
         [0006]     It is another primary object of the present invention to provide an improved intraoral dental mirror that provides improved examination capabilities for the dentist/hygienist.  
         [0007]     Therefore and according to a preferred aspect of the present invention, there is provided an intraoral dental examination instrument comprising:  
         [0008]     an elongated handle; and  
         [0009]     a mirror releasably attached to a distal end of said handle, said mirror including a face portion having a non-plano reflective surface.  
         [0010]     Preferably, the mirror is disposable and is releasably attached to the distal end of the handle of the examination instrument. The handle includes at least one contained battery as well as a miniature light source, such as at least one LED or halogen bulb, that is coupled optically to the end of the releasably attached mirror. The herein described mirror is made from a high quality, light transmissive material such as an acrylic, or other suitable material that promotes effective transmission from the light source to the face portion provided at the distal end of the mirror. The transmitted light is preferably dispersed from at least one light exit surface that is provided at a peripheral portion adjacent the face portion of the mirror, with the face portion being retroflexed relative to a primary axis of the mirror in order to permit enhanced viewing of the upper and lower arches of teeth.  
         [0011]     Preferably and according to one aspect of the invention, at least one surface of the face portion is concave, thereby permitting magnification of the image as presented to the user. According to another aspect of the invention, the surface has a convex curvature in order to present a wider field of view to the user than that of typically known flat or plano mirrored surfaces. As such, the face surface of the herein described mirror can selectively be made to enhance examination of a patient in order to better observe the teeth and oral structures. For example, a number of adaptable mirrors can accompany the handle of the present instrument in order to provide this selectability with regard to a patient(s), as needed by the dentist or hygienist.  
         [0012]     An advantage of the present invention is that the mirror is quickly detachable from the handle of the instrument and is disposable either for single-use or single patient use. The mirror is relatively inexpensive to manufacture and can be easily assembled and/or disassembled to and from the remainder of the instrument.  
         [0013]     A further advantage of the present invention is that improved visibility is provided by use of a image magnifying or improved field of view features of the face surface of the releasably attachable mirror. Moreover, the mirror provides efficient and fairly direct illumination to the coupling of the LED or other miniature light source therewith. A further advantage of the present invention is that the herein described instrument can be used without need for overhead lighting. Additionally, the use of the instrument substantially eliminates the use of loupes or similar apparatus for inspection  
         [0014]     These and other objects, features and advantages will become readily apparent from the following Detailed Description which should be read in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     FIGS.  1 ( a ) and  1 ( b ) represents a side perspective view and a partially sectioned view, respectively, of a prior art intraoral dental examination instrument;  
         [0016]      FIG. 2  is a top perspective view of an intraoral dental examination instrument made in accordance with a preferred embodiment of the present invention;  
         [0017]      FIG. 3  is a sectioned view of the intraoral dental examination instrument of  FIG. 2 ;  
         [0018]      FIG. 4  is a side perspective view of the light guide of the intraoral dental examination instrument depicted in  FIGS. 2 and 3 ;  
         [0019]      FIG. 5  is a partial exploded view of the intraoral dental examination instrument of  FIGS. 2 and 3 ;  
         [0020]      FIG. 6  is an exploded view of an illumination cartridge used in the intraoral dental examination instrument of  FIGS. 2-5 ;  
         [0021]      FIG. 7  is a partial sectioned view of the illumination cartridge of  FIG. 6  as assembled in the intraoral dental examination instrument of  FIGS. 2-5 ;  
         [0022]      FIGS. 8 and 9  are partial side sectioned views of the dental intraoral examination instrument of  FIGS. 2-4  showing a retractable switch assembly illustrating same in respective OFF and ON positions;  
         [0023]      FIG. 10  is a partial diagrammatic view of the optical coupling between the illumination cartridge of  FIG. 6  and the releasably attached mirror in accordance with present invention;  
         [0024]      FIG. 11  is an exploded view of a dental intraoral instrument made in accordance with another preferred embodiment of the present invention; and  
         [0025]      FIG. 12  is an enlarged perspective view of a portion of the instrument of  FIG. 11  depicting a mechanical detent used therewith. 
     
    
     DETAILED DESCRIPTION  
       [0026]     The following description relates to an intraoral dental examination instrument that is made in accordance with certain preferred embodiments of the present invention. Throughout the course of discussion that follows several terms, such as “top”, “side”, “lateral”, “bottom”, “distal”, “proximal”, “front”, “rear”, and the like are used in order to provide a convenient frame of reference with regard to the accompanying drawings. These descriptions, however, unless indicated otherwise, should not be regarded as limiting with regard to the present invention.  
         [0027]     Prior to discussing the present invention and referring first to  FIG. 1 , there is illustrated an intraoral dental examination instrument  20  (partially shown according to the figure) that is made in accordance with the known art, described herein for background purposes. The examination instrument  20  is defined by an elongated body section  24 , a front end cap  28  and a rear end cap  32 , each preferably made from a moldable plastic or from any suitable low heat absorbing material.  
         [0028]     Inserted into the front or distal end  36  of the front end cap  28  of the examination instrument  20  is a mirror  40  having a shank portion  40   a , a heel portion  40   b , and a face portion  40   c . Mirror  40  is of the type that is described in greater detail in U.S. Pat. Nos. 5,457,611 and 5,139,421, in which light transmitted into the shank portion  40   a  from a contained bulb is emitted from the heel portion  40   b  and the face portion  40   c  on both facing sides of the mirror  40 . The subject matter of each of the above-noted patents is herein incorporated by reference in its entirety. An electrical cord  48  containing a pair of wires  52  is inserted into the rear end cap  32 , using a cord grip  56 , to provide the energy from an exterior power supply (not shown) such as, for example, a 110 volt wall outlet, in order to operate the examination instrument  20 .  
         [0029]     The front end of the body section  24  of the instrument  20  includes a plurality of collet-like sections (not shown) as well as a threaded section (not shown) enabling interconnection of the front end cap  28  to the body section  24  as well as the mirror  40  to the instrument. When the mirror  40  is inserted into the front end of the body section  24 , the front end cap  28  is rotated onto the end of the body  24  by virtue of mating threaded sections on each of the body and the front end cap, respectively, with the collet-like segments being caused to tighten around the shank portion  40   a  of the mirror  40 , thereby holding the mirror securely in position within the elongated body section  24  of the instrument  20 . Additional detail is provided in the above incorporated U.S. Pat. Nos. 5,457,611 and 5,139,421.  
         [0030]     Referring to  FIG. 1 ( b ), the electrical cord  48  extending from an external power supply (not shown), is received within a molded lamp assembly unit  62  that is situated at the rear end of the body section  24  through an opening  61  formed in the rear end cap  32  and wires  52  are attached into the unit to a pair of electrical connectors  66 . A miniature high intensity lamp  70 , such as a miniature halogen bulb, is connected to the opposite ends of the connectors  66 . The lamp  70  is positioned within the confines of the elongated body section  24  at one end of a heat sink  74  at close approximation to the shank portion  40   a  of the mirror  40 , the latter being made from a light transmissive material, the lamp further containing a lens  78  that is configured and designed for focusing the light from the lamp into the end of the shank portion  40   a . The heat sink  74  is extensive for purposes of this instrument  20  and includes separate portions that cover each of the lamp assembly unit  62  and light transmissive shank portion  40   a  of the mirror  40 . In addition, a light weight gripping handle  25  covering the elongated body portion  24  includes a series of vent holes  26  also used for dissipating the heat that is generated by the instrument during use. As noted, additional details relating to this examination instrument  20  are described in U.S. Pat. No. 5,454,611, previously incorporated by reference herein.  
         [0031]     Referring now to  FIGS. 2 and 3 , there is shown an intraoral dental examination instrument that is made in accordance with a preferred embodiment of the present invention. The instrument  90 , as now described in brief, includes an elongated body  108  that, like the preceding, includes a front end cap  114  and a rear end cap  115 , respectively, each of which are releasably attached to the body as well as a mirror  100  that is preferably releasably attached to a distal end  104  of the instrument. The front end cap  114 , includes threaded portions that engage with respective threaded portions formed in the front end of the body  108 . The rear end cap  115 , according to this embodiment snaps into place onto the rear or proximal end of the body  108 . Preferably the body  108 , as well as the front and rear end caps  114 ,  115 , are each manufactured from plastic or a similar low heat absorbing material such as Radel-R, polyphenylsulfone or suitable polymer or other low heat absorbing material that permits autoclaving.  
         [0032]     Unlike the preceding described examination instrument of FIGS.  1 ( a ) and  1 ( b ), however, the herein described examination instrument  90  does not require an exterior power supply, the present instrument being cordless and powered by a set of stacked batteries  110  that are retained within a defined battery compartment  111 ,  FIG. 5 , that is provided in the interior of the body  108 . According to this embodiment, the batteries  110  are alkaline, but can also be nickel-cadmium or other suitable type, the batteries also preferably being rechargeable.  
         [0033]     An illumination cartridge or housing  112  is also retained according to this embodiment within the body  108  adjacent the distal end  104  thereof and distal relative to the contained batteries  110 , the cartridge being described in greater detail below. The batteries  110  are retained in biased relation within the body  108  of the instrument  90  relative to the illumination cartridge  112  by means of a compression spring  180  that is positioned adjacent the rear end cap  115 .  
         [0034]     The examination instrument  100  of this specific embodiment further includes a switch assembly  170 , preferably contained in the rear or proximal end of the instrument  90 , the switch assembly according to this preferred embodiment including a retractable plunger  178  containing a pin that moves between respective ON and OFF positions in order to selectively provide an electrical connection between the contained batteries  110  and the illumination cartridge  112  in order to energize an LED  120  retained by the cartridge, as will be described in greater detail below.  
         [0035]     Prior to describing the interior features of the instrument  90 , and referring first to  FIGS. 2-4 , the mirror  140  of the herein described instrument  90  includes an elongated shank portion  144 . The shank portion  144  has a proximal end  148  that includes a defined light entrance surface  137 , the shank portion terminating at a heel portion  146  having a pair of opposing substantially parallel light exit surfaces  147  on each of the top and bottom sides (only the top surface is shown in  FIGS. 2-4 ) thereof, each of which are angled relative to a primary axis  149  that extends through the shank portion. A face portion  152  is integrally formed at the distal end of the mirror  140  along an axis (not shown) coextensive with that of the heel portion  146 . The face portion  152  according to this embodiment is substantially circular in configuration (though other shapes could be contemplated) and includes a non-plano mirrored surface  156 . The mirror  140  according to this embodiment is entirely made from a high-quality light transmissive material, such as acrylic, polyamide, polycarbonate and the like, and is preferably molded including the face portion  152  and the mirrored surface  156 . The reflective portion of the mirror assembly  140  is molded according to this embodiment using “In Mold Decoration” technology wherein the contour of the mirrored surface  156  is controlled by the shape/contour of the mold. According to this embodiment, the non-plano mirrored surface  156  is concave in curvature in order to provide magnification of the object(s) being examined. According to this embodiment, about a 1.5× magnification is created although this parameter can easily be varied. It should be noted that in the alternative that the non-plano mirrored surface  156  can also be made with a convex curvature, wherein a minified image can be produced, thereby creating a wider field of view which can be useful for certain oral applications.  
         [0036]     Referring to  FIGS. 5-7 , the illumination cartridge  112  of the described embodiment consists of a cylindrical housing body  116  made from Radel R, polyphenylsulfone or suitable polymer, but can be fabricated from literally any electrical insulating material, wherein a miniature LED  120  is disposed at a distal end  104  adjacent a reflector cap portion  128  that is attached in overlaying relation thereto. The illumination cartridge  112  further includes a printed circuit board (PCB)  130  that contains suitable electronics  134  thereupon used for powering the miniature LED  120 . The PCB  130  according to this embodiment is disposed immediately below or proximal to the miniature LED  120 , and includes an opening  129  for receiving the projecting portion  161  of a heat sink  160 , retained by the housing body  116  in order to dissipate heat that is generated by the miniature LED, as well as the PCB  130 .  
         [0037]     The reflector portion  128  is defined by a through opening  136  that is fitted about the lens envelope  122  of the miniature LED  120 , the through opening preferably having an inwardly tapered surface  136  that is used in order to focus the light emitted from the miniature LED  120  onto a light entering surface  137  of the shank portion  144  of the mirror  140 , as shown more particularly in  FIGS. 7 and 10 . The illumination cartridge  112  is retained by the front end cap  114  and is held in place by the body  108  and a contact strip  194  of an internal cage member  190 . The reflector portion  128  also recesses the lens  122  and protects lens from damage, such as from dropping the cartridge  114 , when removed from the instrument for cleaning.  
         [0038]     Referring to  FIGS. 5, 8  and  9  and as previously noted herein, the examination instrument  90  is powered by means of a switch assembly  170  provided at the rear portion of the body  108 . A retractable plunger  178  is mounted into the rear end cap  115  and includes a spring loaded pin member  181  that is selectively engageable with an S-shaped conformable spring member  182 . As the retractable plunger  178  is pushed by the user from the OFF to the ON position, shown in  FIGS. 8 and 9  respectively, the pin member  181  is caused to engage with the S-shaped spring member  182 , which conforms and causes the battery contacts to engage with a conductive laterally extending contact strip  194  disposed on a hollow cylindrical internal cage member  190  covering the interior of the handle  108 , the strip providing electrical connectivity with the contained cartridge  112 , when the battery contacts engage the strip  194  as shown in  FIG. 9 , with the S-shaped spring member  182  in relation to electrical contacts. The internal cage  190  is used to hold and retain the conducting strip  194  and to provide centering for the batteries  110 . The internal cage  190  further positions a small conductive plate  183  laterally, the plage being disposed adjacent to and proximal of the compression spring  180 .  
         [0039]     In operation, the mirror  100  is first attached to the examination instrument  90  using colleted portions (not shown) which are formed in the distal end of the handle  108 . The front end cap  114  is then threaded onto the distal end of the handle  108  in order to secure the mirror  140  in place. The illumination cartridge  112  is attached to the distal end of the handle  108  by threaded portions. In this position, the shank portion  144  of the mirror  140  is situated in relation to the miniature LED  120 .  
         [0040]     The instrument  90  is initially in the “OFF” position shown in  FIG. 8 . As noted, depression of the retractable plunger  178  of the switch assembly  170  causes the contained pin member  181  to engage with the S-shaped spring member  182 , causing relative movement of the S-shaped spring member and allowing the battery contacts to be brought into electrical contact with the illumination cartridge  112 , by virtue of coextensive top and bottom ends  195 ,  196  respectively of the conductive laterally extending strip  194 , thereby energizing the contained LED  120 . Emitted light from the miniature LED  120  is then focused, by virtue of the reflector portion  128  onto the light transmissive shank portion  144  of the mirror  100 . The mirror  140  thereby provides suitable illumination at the exit surfaces  147  of the heel portion  146  and the face portion  152 , wherein the non-plano mirrored surface  156  permits enhanced examination of the teeth.  
         [0041]     Following use, the mirror  140  can be removed by reversing the threading of the front end cap  114  and pulling same from the colleted areas of the body  108 . The front end cap can then be removed, permitting access to the illumination cartridge  112  can be removed by reversing the threaded portion of the body  108  and the distal cap  114  from the body  108  along with the batteries  110 , once the mirror  140  has also been removed from the distal end of the examination instrument  90 . Once removed, the body  108  as well as the front and rear end caps  114 ,  115  can then be autoclaved.  
         [0042]     Referring to  FIG. 11 , there is shown an intraoral dental examination instrument  200  made in accordance with a second preferred embodiment of the present invention. The examination instrument  200  according to this embodiment includes a plastic molded handle body  204 , the body defined by a cylindrical configuration and having a pair of open ends  208 ,  212  that further define a hollow interior  216  which is sized for retaining a cylindrical interior cage member  220 . The interior cage member  220  is preferably also made from plastic or similar insulating material which is also preferably autoclavable and includes a plurality of lateral slots that are defined along the axial length thereof, the interior cage member further having means for supporting an electrically conductive battery contact strip  227 , the strip including a contact spring  231  at a proximal end thereof. The interior cage member  220  is also open-ended and has a hollow interior that defines a battery compartment which is appropriately sized for receiving a pair of stacked cadmium, alkaline or other suitable batteries  229 . The contact spring  231  serves as a contact for the stacked batteries  229 , relative to a battery contact disk  233  that is interposed between the contact spring and an endcap  235  that is fitted onto the proximal open end  212  of the handle body  204 .  
         [0043]     The distal end  208  of the handle body  204  of the examination instrument  200  includes a set of exterior screw threads  238  permitting the connection of a mirror support collet  240 , as well as a collet locking ring  243  that retains a disposable mirror  247 . The mirror support collet  240  is defined by a rotatable exterior knob  249  that includes a set of interior threads (not shown). The collet locking ring  243  is threadingly mounted onto the exterior of the mirror support collet  240 , while the disposable mirror  247  includes an elongate shank portion  251  that is engaged with the collet locking ring, the collet locking ring being rotated to tighten or loosen the grip on the disposable mirror to permit engagement or disengagement therewith. The mirror  247  is similar in design to that previously described having the shank portion  251 , a face portion and further including a non-plano reflective surface.  
         [0044]     Disposed between the stacked batteries  229  and the mirror support collet  240  is an illumination assembly  260  that includes a hollow cylindrical cartridge body  264  containing a plurality of interconnected components. Among these contained components are a heat sink  268  onto which is packaged an LED driver circuit board  272 . A miniature LED package  276  is disposed distally from the LED package  276  as well as a cartridge cap  280  having an inwardly tapered surface that is used to focus light from the miniature LED onto a light entering surface of the disposable mirror  247 . A battery contact board  284  is disposed in the bottom of the cartridge body  264 , each of which are held by a cartridge collar  288  that accommodates the illumination cartridge assembly  260  within the distal end of the handle body  204 , when assembled thereto.  
         [0045]     The herein described dental examination instrument  200  further utilizes a rotary switch assembly in order to selectively illuminate the miniature LED package  276  that is housed in the illumination cartridge assembly  260 . The rotary switch assembly is enabled by rotating the rotatable exterior knob  249  of the mirror support collet  240  relative to the threads  238  of the distal end of the body  204 , causing the illumination cartridge  260  to move into contact with the batteries  229 . As the batteries  229  are pushed axially against spring  231  the strip  227  contacts cartridge collar  288  and creates a negative electrical contact. The battery contact  284  board contacts the positive battery terminals, completing the circuit and energizing the LED  276  with the strip  227  and contact disk  233   
         [0046]     Referring to  FIGS. 11 and 12  and in order for the user to properly sense actuation of the LED  276 , a spring member  294  is preferably sandwiched between the exterior of the internal cage member  220  and the interior of the body  204 . The spring member  294 , in this instance, a leaf spring, is fastened at one end to a slot of the internal cage member adjacent the distal end thereof  220  by conventional means in this case, by means of an interference fit, the spring member including a depending engagement end portion  298  that initially resides in a groove  296  which is provided at the distal end of the internal cage member  220 . When the internal cage member is inserted into the interior of the body  208 , the spring member  294  is biased such that the engagement end portion  298  is caused to extend through a small opening (not shown) that is provided in the external threads  238  of the body  204  that is sized to accommodate same.  
         [0047]     In operation, the mirror support collet  240  is attached to the distal end of the body  204  by threading the internal threaded portion thereof with the external threads  238  provided on the distal end  208  of the body. As the collet supporting ring  243  and collet  240  is rotated thereupon in a clockwise manner to initiate engagement, the LED  276  is caused to illuminate due to the above electrical connection that is created between the illumination cartridge  260 , including the contained LED, and the batteries  229 . As the above procedure is reversed, the LED  276  is deenergized upon counterclockwise rotation of the collet supporting ring  243  and collet  240  relative to the body  204  of the instrument whereupon the engagement end portion  298  is arranged relative to a hollow depression that is formed on the interior of the collet  240  into which the engagement end portion repeatably slips when the LED OFF position is reached as mechanically sensed by the user in the form of a detent.  
       PARTS LIST FOR FIGS.  1 - 12   
       [0000]    
       
           20  dental intraoral examination instrument  
           24  elongated body portion  
           25  gripping handle  
           26  slotted vent holes  
           28  front end cap  
           32  back end cap  
           36  distal end  
           40  mirror  
           40   a  shank portion  
           40   b  heel portion  
           40   c  face portion  
           48  electrical cord  
           52  wires  
           56  cord grip  
           61  opening  
           62  lamp assembly unit  
           66  electrical connectors  
           70  lamp  
           74  heat sink  
           78  lens  
           90  dental intraoral examination instrument  
           100  mirror  
           104  distal end  
           108  body  
           110  batteries  
           112  illumination cartridge  
           114  front end cap  
           115  rear end cap  
           116  housing body  
           120  LED  
           122  lens envelope  
           124  distal end  
           128  reflector portion  
           130  printed circuit board  
           131  opening  
           132  through opening  
           134  electrodes  
           136  inwardly tapered surface  
           137  light entering surface  
           140  mirror  
           144  shank portion  
           146  heel portion  
           147  light exit surface  
           148  proximal end  
           149  primary axis  
           152  face portion  
           156  non-plano mirrored surface  
           170  retractable switch assembly  
           178  plunger  
           180  spring, compression  
           181  pin member  
           182  spring member, S-shaped  
           183  conductive plate  
           190  internal case member  
           194  laterally extending electrical conductive strip  
           195  top end, strip  
           196  bottom end, strip  
           200  intraoral dental examination instrument  
           204  handle body  
           208  open end  
           212  open end  
           216  hollow interior  
           220  interior cage member  
           227  electrically conductive battery contact strip  
           229  batteries  
           231  contact spring  
           233  battery contact disk  
           235  endcap  
           240  mirror support collet  
           243  collet supporting ring  
           247  disposable mirror  
           251  elongate portion  
           260  illumination cartridge assembly  
           264  cartridge body  
           268  heat sink  
           272  LED driver circuit board  
           276  LED package  
           280  cartridge cap  
           284  battery contact board  
           288  cartridge collar  
           290  rotary switch assembly  
           294  spring  
           296  groove  
           298  engagement end portion  
           300  hollow depression  
       
     
         [0133]     Other variations and modifications will be readily apparent to one of sufficient skill in the field that embody the inventive concepts taught in the above specification and are recited in the following claims.