Patent Publication Number: US-2011076640-A1

Title: Orally implantable intraosseous port

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of Provisional Application No. 61/130,968, filed Jun. 5, 2008, and claims priority therefrom. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to devices for implantation in the human body and, more particularly, to a dental implant device for providing therapeutic access to the medullary space of the maxillae and mandible in the human mouth in order to facilitate the deposition of therapeutic agents and the extraction of bone marrow contents. 
     When the device is bonded to the bony tissue of the jaw and the overlying tissues through which it is inserted, it will serve as a permanent indwelling device in like fashion to contemporary osseointegrated dental implants. As such, this device may be used ad libitum and ad infinitum for the injection of systemic and local therapeutic agents and the extraction or monitoring of components contained within the marrow space. Its hollow interior forms a port that is sealed and/or unsealed at will by a removable core. When sealed internally by its removable core, and sealed externally by its bonding to bone, it is impervious to microbial penetration and profoundly resistant to infection. 
     2. Description of the Related Art 
     Intraoral intraosseous drug delivery systems have been used for decades for the delivery of local anesthetic solutions to the medullary space proximate to areas undergoing dental treatment. Extraoral transdermal intraosseous devices have been used in recent times for emergency access to the systemic circulation; that is, intraosseous injection ports are in current use to gain access for emergency drug administration through the patella and sternum. Such extraoral intraosseous drug delivery systems as are known to create an unsealed pathway through the dermis, that makes it vulnerable to infection by dermalborne microbes. In hospitals and long-term clinical facilities, nosochomial microbes are extraordinary virulent and drug resistant. Long-term intraosseous ports (that are transdermal and extraoral) place patients at an increased risk for serious and sometimes lethal microbial disease from nosochomial sources. Current intraosseous drug-delivery systems of the prior art are thus useful for only limited time periods and are not sealed internally or bonded externally in order to prevent the ingress of locally invasive microbial disease which is proximate to these devices. 
     There are prior art devices which comprise an apparatus for intraosseous dental anesthesia and a method of use. Such apparatus, as known, has separate elements which require more time for installation. The threaded housing of the apparatus that is implanted into the patient is devoid of any sealing element, thereby limiting repeated use of the same device. 
     Typically, a prior art intraosseous infusion device uses an inclusion tube or needle having an enlarged threaded tip that is threaded into the bone of a patient. Such a device requires an operator for continuously monitoring the resistance between the device and the bone during threading. Moreover, the enlarged tip of the device damages the outer bone and leaves a hole in the outer bone that causes possible leakage of infused liquid. 
     Some of the conventional systems disclose an apparatus and a method for catheterized delivery or infusion of medication and anesthesia. Such apparatus fails to provide a prolonged access to medullary spaces. The repeated removal and insertion of such apparatus may result in nosochomial bacterial infections from dermal-borne microbes. 
     There is a definite need for a port that allows for injection of therapeutic agents into the medullary space and extraction of medullary space contents. The device of the invention may be permanently implanted in the patient&#39;s maxillae and/or mandible in a safe and effective manner. It is more resistant to infection than currently available intraosseous ports and therefore represents a novel system for long-term access to the bone marrow of the jaws for a multitude of purposes. 
     SUMMARY OF THE INVENTION 
     In brief, one particular embodiment of the present invention is an orally implantable device called a TiPort™ (Titanium Port), which is analogous to contemporary dental implants. As such, it comprises a self-tapping screw fabricated of titanium, which is well-documented as having biocompatibility of long-term duration. Unlike dental implants that are intended to support prosthetic teeth, it features a novel hollowed internal design that will accommodate a conventionally sized hypodermic needle for injection or extraction of substances into and out of the marrow space of maxillae and mandibles. 
     An internal core is secured by internal threads that function in opposite direction to the external threads of this device. The hollowed interior, or “port”, is obturated by a multitude of core designs. One core type is designed for sealing only. A second core type incorporates a cutting tip that renders the entire device a self-tapping screw. This cutting tip is designed so as not to carry contents (which would normally accompany the implant) into the medullary space. A third core device is hollowed to allow for connection to a flexible external line and thus allow for fluid to traverse it to and from the external line. 
     One preferred embodiment of the invention comprises an implant housing component that is implanted into the cortical bone of the mandible. A drill bit component that produces a bore within the mandible (for initiating the implanting of the implant housing component), and a seal plug component that is removably mounted within the implant housing component allows for repeated access of a hypodermic needle into the mandible. 
     The implant housing component has an integrated tapered, self-tapping external thread that eliminates the risk and necessity of a separate step to tap threads into the cortical bone. The intraosseous injection of medication to the medullary cavity of a jawbone and the extraction of medullary bone contents are delivered through a chamfered channel within the implant housing component. The drill bit component has a hollow stylus with a sharpened tip at its distal end to drill the cortical bone of the mandible. The seal plug component (comprising a stylus with a flattened tip) has an external dimension that complements the internal dimension of the bore of the implant housing component. 
     The TiPort™ is implanted into the cortical bone of the mandible by placing the assembly of the implant housing component and the drill bit component on the cortical bone of the mandible. The implant housing component is installed into the mandible by rotating the assembly in a clockwise direction with a powered hand drill, using a drill bit with a socket head to engage the square head of the implant housing component. 
     The drill bit component within the bore of the implant housing component has a head with a slot, like a slotted screw, and it mates with internal left-hand threads in the bore of the implant housing component. After the implant housing component is seated in place, the drill may be fitted with a blade driver and the drill bit component removed from the left-hand threaded bore by rotating the drill bic component in a clockwise direction with a powered hand drill. Alternatively, a blade screwdriver may be used to remove the drill bit component. A Phillips-head or Allen-head screwdriver or other tool may be used as well. Thereafter a seal plug component is installed into the implant housing component by rotating the seal plug component in a counter-clockwise direction with a standard manual screwdriver. 
     Although the above description involves a right-hand external thread of the implant housing component, and the internal thread of the bore of this component involves a left-hand thread to accommodate the left-hand thread on the drill bit component, the orientation of the screw threads may be reversed, if desired, so that the external thread of the implant housing component is a left-hand thread, in which case the internal thread of the implant housing component and the external thread of the core would be right-handed. The important point is that these threads be opposite in direction to facilitate their manipulation into the mandible opening. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1A  is a schematic view of the components of the preferred embodiment of the invention involved in the drilling and installation of the permanent implant housing component; 
         FIG. 1B  is a schematic view of the same components shown in  FIG. 1A , but from a different viewpoint; 
         FIG. 2  is a schematic view of the complete assembly of the components involved in the drilling and installation of the permanent implant housing component utilizing a powered hand drill common to the practice of dentistry; 
         FIG. 3A  is a schematic view of the drilling and installation process of inserting the permanent implant housing component into the mandible, utilizing a powered hand drill; 
         FIG. 3B  is a more detailed view of the drilling and installation process of inserting the permanent implant housing component into the mandible, showing the clockwise rotation to drive the implant housing component into the cortical bone of the mandible; 
         FIG. 3C  shows the removal of the internal drill bit component utilizing a powered hand drill that provides a clockwise rotation with a screwdriver blade attachment, withdrawing the bit component by virtue of the left-hand threads within the bore of the implant housing component; 
         FIG. 3D  is a schematic view showing the installation of the seal plug component that mates with the internal threads and sealing surfaces of the implant housing component. This seal plug component is installed using a counter-clockwise rotation provided by a standard manual screwdriver; 
         FIGS. 4A and 4B  are two views of one particular version of the implant housing component; 
         FIGS. 5A and 5B  are views of the drill component of the device of the invention; 
         FIGS. 6A and 6B  are views of the seal plug component for insertion in the implant housing component; 
         FIG. 7  is a schematic view of intraosseous infusion utilizing a standard syringe; 
         FIG. 8  is a cross-sectional view of the assembly with the tip of the needle inserted in the hollow cavity of the implant housing component from which the seal plug has been removed. This hollow cavity features a tapered profile that forms a sealing surface with the end of the needle, as shown in  FIG. 5 ; 
         FIG. 9A  is an exploded view of a coupler used to connect an intravenous line to the implant housing component to provide intraosseous infusion to the mandible; 
         FIG. 9B  is a schematic view of an assembly having the intravenous line connected; 
         FIG. 9C  is a schematic view showing the assembly of  FIG. 9B  inserted in the mandible; 
         FIG. 10  is a schematic view showing intraosseous infusion to the mandible, utilizing an intravenous line attached to a 90° coupler; 
         FIG. 11A  is an enlarged view of the assembly of the implant housing component and drill bit component used during the drilling and implant process; 
         FIG. 11B  is a view of the same components of  FIG. 11A , but from a different vantage point; 
         FIG. 12  is an enlarged view of the implant housing component; 
         FIG. 13  is a schematic view of the drill bit component; 
         FIG. 14  is a schematic view of the seal plug component; 
         FIG. 15  is an enlarged view of the assembly of the implant housing component and the seal plug component; 
         FIG. 16  is a sectional view illustrating the interrelationship of components involved during the drilling and installation of the implant assembly into the mandible; 
         FIG. 17A  is a more detailed sectional view showing the drilling and installation of the implant housing component into the mandible by clockwise rotation (indicated by the arrow  27 ); 
         FIG. 17B  is a more detailed sectional view showing the removal of the drill bit component, also clockwise, from the installed implant housing component; 
         FIG. 17C  is a more detailed sectional view showing the installation of the protective seal plug component (driven counter-clockwise) into the installed implant housing component; 
         FIG. 17D  is a detailed sectional view showing an intravenous line connected to the installed implant housing assembly for intraosseous infusion into the mandible; 
         FIG. 18A  is a schematic view of an alternative design of the drill component and its matching drive socket that provides for increased stability during the process of drilling and installing the implant housing component; 
         FIG. 18B  is a schematic view of the drill bit component of  FIG. 18A  prior to the completion of the installation of the implant housing component; and 
         FIG. 19  is an enlarged sectional view showing the relationship of the drill component of  FIGS. 18A and 18B  and its matching drive socket during the process of installing the implant housing component into the mandible. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1A and 1B  are exploded views of a device  10  in accordance with the invention for intraosseous injection of medication to the medullary cavity of a jawbone (not shown) and the extraction of medullary bone contents. The device  10  includes an implant housing component  12 , a drill bit component  14  which is installed into the implant housing component  12 , and a drill driver  16  with a socket  18  to mate with the head  13  of the implant housing component  12 . 
       FIG. 2  shows the assembled device  10  coupled to the socket  18  of the driver  16  which is installed in the chuck  22  of a powered hand drill  20 . The hand drill  20  initiates the drilling and installation of the device  10  into the mandible  24  ( FIGS. 3A and 3B ). 
     The implant housing component  12  is hollow with a bore region that is threaded with left-hand thread  13  to receive the drill bit component  14  which is also provided with a left-hand thread. As combined to establish the device  10 , the device  10  is shown in  FIGS. 3A and 3B  as having been driven by the drill  20  into the mandible  24 . 
     The drill bit component  14  within the implant housing component  12  is driven into the cortical bone of mandible  24  by the drill  20  and establishes a hole by virtue of the self-tapping threads  15  of the implant housing component  12 . In the driving of the device  10  into the mandible  24 , the assembly  10  is rotated in a clockwise direction and a powered hand drill  20  is utilized for its insertion. 
       FIGS. 3C and 3D  show the use of a driver  16 , which may either be used as a hand implement or within the chuck  22  of the drill  20  to, first, remove the drill component  14  from the implant housing component  12  by driving it in the clockwise direction ( FIG. 3C ); and then, using the same blade driver, rotate it in a counter-clockwise direction ( FIG. 3D ) to insert a threaded seal plug  26  into the implant housing component  12 . 
     The elements comprising the device  10  of the present embodiment of invention are shown in further detail in  FIGS. 4A-6B . 
       FIGS. 4A and 4B  show the device assembly  10  including the drill component  14  within the implant housing component  12  which has self-tapping threads  15  and a square head  13  for engaging the socket  18  of the driver  16 . As shown in  FIGS. 4A and 4B , the head  13  is covered by a removable cap  19 . 
       FIGS. 5A and 5B  portray the drill component as having a hollow center  31  terminating in a beveled tip  32 . 
       FIGS. 6A and 6B  show a variant of the drill component labeled  14 ′ which has a double-beveled tip  32 ′. 
       FIG. 7  shows a hypodermic syringe  40  coupled to the implant housing component  12  for the intraosseous injection of medication to the medullary cavity of the jawbone  24  and also the extraction of medullary bone contents by way of the device  12 . This is better shown in the enlarged cross-sectional view of  FIG. 8  wherein the needle  41  is inserted into the bore  17  of the implant housing component  12 . This bore  17  is a chamfered channel with a tapered profile that forms a sealing surface with the needle  41 . The needle  41  is also tapered at its tip  42  to enhance the sealing capability of the two adjacent surfaces. 
     The sectional view of  FIG. 8  also shows the external self-tapping threads  15  of the implant housing component  12  and the internal self-tapped threads  15 ′ in the mandible  24 . 
     As part of the system of the invention, provision is made for the coupling of an intravenous line  56  into the implant housing component  12 . 
     This is shown in  FIGS. 9A and 9B  as including a hollow coupler  50 , having a recessed surface  52  and a slotted end  54  for receiving one end of the intravenous line  56 . These are shown in assembled form in  FIG. 9B .  FIG. 9C  shows the assembly of  FIG. 9B  connected to the mandible  24 . 
       FIG. 10  shows a coupler  51  connecting the intravenous line  56  with the implant housing component  12  through a 90° elbow attachment. This arrangement facilitates the delivery of medication and extraction of fluids from the medullary cavity for a longer duration, such as when lying flat on the bed. 
       FIGS. 11A and 11B  show schematic views of the assembly of the implant housing component  12  and the drill bit component  14 . The square drive head  13  at the proximal end of the implant housing component  12  allows for torque transfer to the sealing surface  23  of the implant housing component  12 . The square drive head  13  is engaged with at least one of a powered hand drill  20  and/or a hand wrench (not shown) to drive the implant housing component  12  into the cortical bone of the mandible  24 . 
       FIG. 12  shows a schematic view of the implant housing component  12  having a cylindrical bore  44  that allows for the insertion of the drill bit component  14 . 
       FIG. 13  shows a schematic view of the drill bit component  14  as shown in  FIG. 5A . The drill bit component  14  produces a bore  17  within the mandible  24  for initiating the implanting of the implant housing component  12 . 
       FIG. 14  shows a schematic view of a seal plug component  26  having a stylus  30  with a flattened end  29  and an external thread  36  that matches the internal threads of the implant housing component  12 , and a head  13  with a screwdriver slot  21 . 
       FIG. 15  shows a schematic view of the assembly of an implant housing component  12  and a seal plug component  26  with flattened end  29  that is removably mounted within the implant housing component  12 . Removal of the plug  26  allows repeated access of a hypodermic needle  41  into the mandible  24 . 
       FIG. 16  shows a cross-sectional view of the drilling and installation process of the implant housing component  12  into the mandible  24 , using the drill driver  16  and socket  18 . 
       FIGS. 17A and 17B  show the cross-sectional view of the removal process of the drill bit component  14  from the installed implant housing component  12 , using a bladed driver  16 . 
       FIG. 17C  is a cross-sectional view of the installation of the seal plug component  26  into the installed implant housing component  12 . The external threaded portion  35  of the seal plug component  26  is accommodated in the internal threaded portion  34  of the implant housing component  12 . 
       FIG. 17D  is a cross-sectional view showing the intraosseous infusion by way of the intravenous line  56  and coupler  50  threaded into the implant housing component  12  which is driven into the cortical bone of the mandible  24 . 
       FIG. 18  is a schematic view with an alternate design of the drive socket  18  and drill component. The head of the drill component is substantially longer in this design and a matching deep socket ( FIGS. 18A , B) with matching deeper receptacle  36  is used for improved stability. 
       FIG. 19  is a detailed sectional view showing the interrelationship of the alternative design of the drill bit component  14 A and its matching drive socket  18 A during the drilling and installation process of the implant housing component  12  into the mandible  24 . 
     In summary, the device of the invention is an improved permanent dental implant that allows virtually instantaneous access to the medullary cavity in the human jaw with a reduced risk of nosochomial bacterial infection. 
     Although there have been described hereinabove various specific arrangements of a TiPort™ in accordance with the invention for the purpose of illustrating the manner in which the preferred embodiment of the invention may be used to advantage, it will be appreciated that the invention is not limited thereto. Accordingly, any and all modifications, variations or equivalent arrangements which may occur to those skilled in the art should be considered to be within the scope of the invention as defined in the annexed claims.