Modular template for drilling holes and method of making same

Abstract

A template for use with an instrument to drill a hole in a surface at a desired location. The template includes a body which has a negative impression of the surface, and a guideway having a first end positioned to open onto the desired location when the body is placed in conforming contact with the surface and a second end positioned on an exterior surface of the body. The second end of the guideway is connected to the first end by a passage. The guideway is preferably positioned in a portion of the template which is removable from the remainder thereof. The template also includes a stop for limiting the depth of penetration of the drill bit into the hole, a first fastener for attaching the stop to the body and a second fastener for fastening the removable portion of the template to the remainder of the template.

Claims

1. A template for use with an instrument for penetrating an uncut irregular surface through a hole in said uncut irregular surface, said hole being located at a desired location on said uncut irregular surface, said template comprising: a body including a custom surface shaped as a negative impression of the uncut irregular surface to conform to the uncut irregular surface, the body having a receiving section; a removable portion configured to seat in the receiving section of the body; said body further including a guideway that is detachably connected to the removable portion and having a first end positioned to open onto said desired location when said body is placed in conforming contact with said uncut irregular surface; said guideway having a second end positioned on an exterior surface of said body, and connected to said first end by a passage; a radiographic marker arranged in the removable portion; means for securing said removable portion to said body; a stop for limiting a depth of penetration of said instrument into said hole; and wherein the guideway comprises an inner piece including the stop, and an outer piece, and wherein the outer piece includes a threaded inner surface configured to engage threads on a threaded outer surface of the inner piece, and a threaded outer surface.

2. The template of claim 1, wherein said guideway is substantially linear.

3. The template of claim 1, wherein said stop is integrally formed with said inner piece.

4. The template of claim 1, wherein said template is intended for use in surgery.

5. The template of claim 4, wherein said uncut irregular surface is a surface of a bone.

6. The template of claim 5, wherein said bone is a jaw.

7. The template of claim 5, wherein said bone is a cranium.

8. A modular template for use with a drill bit for drilling a hole into an uncut irregular surface at a desired location on said uncut irregular surface, said template comprising: a body including a custom surface shaped as a negative impression of the uncut irregular surface to conform to the uncut irregular surface and a removable portion; said body further including a guideway that is detachably connected to the removable portion and having a first end positioned to open onto said desired location when said body is placed in conforming contact with said uncut irregular surface; said guideway having a second end positioned on an exterior surface of said body, and connected to said first end by a passage; said guideway being positioned in said removable portion; and means for attaching said removable portion to said body, wherein each of said body and said removable portion includes a radiographic marker such that said body comprises a radiographic template for subsequent removable portions, wherein the guideway comprises an inner piece and an outer piece, and wherein the outer piece includes a threaded inner surface configured to engage threads on a threaded outer surface of the inner piece, and a threaded outer surface.

9. The template of claim 8, wherein said means for attaching includes a clip.

10. The template of claim 8, further comprising: a stop for limiting a depth of penetration of said drill bit into said hole, the stop attached to the inner piece.

.Iadd.11. A template for use with an instrument for penetrating an uncut irregular surface through a hole in said uncut irregular surface, said hole being located at a desired location on said uncut irregular surface, said template comprising: a body including a custom surface shaped as a negative impression of the uncut irregular surface to conform to the uncut irregular surface, the body having a receiving section; a removable portion configured to be arranged in the receiving section; a removable guideway arranged at the removable portion and having a first end positioned to open onto said desired location when said body is placed in conforming contact with said uncut irregular surface, wherein the removable guideway comprises an inner piece and an outer piece, and wherein the outer piece includes an outer surface configured to engage an inner surface of the removable portion; means for securing said removable portion to said body; and the inner piece configured as a stop for limiting a depth of penetration of said instrument into said hole..Iaddend.

.Iadd.12. The template of claim 11, wherein the inner piece comprises a ferrule..Iaddend.

.Iadd.13. The template of claim 12, wherein the stop is integrally formed with the ferrule..Iaddend.

.Iadd.14. The template of claim 12, wherein the guideway is substantially linear..Iaddend.

.Iadd.15. The template of claim 11, wherein the uncut irregular surface is a surface of a bone..Iaddend.

.Iadd.16. The template of claim 15, wherein the bone is a jaw..Iaddend.

.Iadd.17. The template of claim 11, further comprising: a modular portion configured as an attachment element of a dental implant prosthesis..Iaddend.

.Iadd.18. The template of claim 11, further comprising: a radiographic marker arranged in the removable portion..Iaddend.

.Iadd.19. A modular template for use with a drill bit for drilling a hole into an uncut irregular surface at a desired location on said uncut irregular surface, said template comprising: a body including a custom surface shaped as a negative impression of the uncut irregular surface to conform to the uncut irregular surface; a guideway that is detachably connected to the body and having a first end positioned to open onto said desired location when said body is placed in conforming contact with the uncut irregular surface, wherein the guideway comprises an inner piece, which is configured as a removable stop, and an outer piece, and wherein the outer piece includes an outer surface fastened to an inner surface of the guideway; the guideway having a second end positioned on an exterior surface of the body, and connected to the first end by a passage; and the removable stop for limiting a depth of penetration of said instrument into said hole..Iaddend.

.Iadd.20. The template of claim 19, wherein at least the body includes a radiographic marker such that the body comprises a radiographic template..Iaddend.

.Iadd.21. The template of claim 19, further comprising: a connector configured to attach the guideway to the body..Iaddend.

.Iadd.22. The template of claim 19, further comprising: a modular portion configured as an attachment element of a dental implant prosthesis..Iaddend.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings, in which like numerals depict like elements:

(2) FIG. 1 is a block diagram showing the steps of the inventive method.

(3) FIG. 2 is a cross-section of a template formed in accordance with the invention.

(4) FIG. 3 is a cross-section of a detail of an alternate embodiment of the inventive template.

(5) FIG. 4 is a cross-section of an embodiment of the invention in which the template is used in cranial surgery.

(6) FIG. 5 is a partial cross-section of a further alternate embodiment of the invention useful in providing distraction osteogenesis.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(7) The inventive template is intended for use with an instrument, such as a drill bit, probe or needle, to provide guidance to the instrument for entering a hole in a surface at a desired location, at a desired trajectory, to a desired depth. In the preferred embodiment, the ultimate purpose of the template is to assist in a surgical drilling procedure, and the surface is part of a body, likely (but not necessarily) human. In the most preferred embodiment, the surgical procedure is part of the procedure for placing a dental implant in a human jaw bone, but one of ordinary skill in the art will appreciate that the procedure has a wider applicability, and is not limited to surgical procedures in general, or dental procedures in the specific.

(8) The basic method of manufacturing a template in accordance with the invention is described in detail in the United States Published Patent Application Publ. No. 2005/0084144 and will not be repeated at length, here.

(9) Briefly, as shown in FIG. 1, the method (designated generally at 10) of manufacturing a template in accordance with the invention includes the following steps:

(10) Placing a substantially radio-transparent malleable material and a plurality of radio-opaque markers in contact with the surface into which the instrument is to be inserted (12). Suitable materials for use as the template include acrylic and silicone.

(11) Forming a negative impression of the surface by conforming the malleable material to a portion of the surface, in the vicinity of the location at which the hole is or will be located (14).

(12) Positioning the markers at defined positions in the maleable material in contact with the surface (16).

(13) Taking a first radiograph of the surface and the malleable material together (18).

(14) Removing the malleable material from the surface (20).

(15) Taking a second radiograph of the negative impression apart from the surface (22).

(16) Comparing the first and second radiographs to determine the shape of the surface (24).

(17) Determining the configuration of the guideway to be placed in the template, depending upon the desired location of the hole in the surface, the desired trajectory for the instrument to enter the hole, and the desired maximum depth of penetration of the instrument into the hole (26).

(18) Forming a template for use with the instrument (28). The template conforms to the negative impression and includes a guideway for the instrument through the template along the desired trajectory, and positioned so that the instrument passes through the guideway to reach the surface at the desired location to enter or form the hole. In one embodiment of the invention, the template includes a removable portion, and the guideway is positioned within the removable portion. In this embodiment, there is an additional step (30) of securing the removable portion to the remainder of the template.

(19) In another embodiment of the invention, there is a still further step (32) of positioning a stop in the template to limit the depth of penetration of the instrument into the hole to the desired depth.

(20) In any embodiment, at this point the template may be positioned (34) on the surface, with the negative impression holding the template in place, and the guideway establishing the proper location and trajectory for the instrument.

(21) The user may then begin to use the instrument, such as to begin drilling (36) through the surface. If a stop is used, the user may insert the instrument until the stop prevents further forward progress, thereby limiting the depth to which the instrument may enter the hole, and defining the maximum depth of penetration of the instrument into the surface. In the case of use of the template with a drill bit, this means that the positioning of the stop limits the maximum depth of a hole drilled into the surface.

(22) In yet another embodiment, the template includes both a stop and a removable portion containing the guideway, and so both steps 30 and 32 may be performed in the same embodiment.

(23) A template manufactured in accordance with the inventive method is shown in FIG. 2, generally at 100. Template 100 is intended for use with an instrument, such as drill bit 102 to drill a hole 104 (shown in dashed line) into a surface 106. In this illustration, surface 106 is a human jaw 108, which includes teeth 110 in the vicinity of the desired location for hole 104. In other dental embodiments, it may be desired to drill into the teeth directly, for example to treat a cavity, or to drill into some other kind of surface, such as a bone in another part of the body, for example the skull, or in an animal's bone in veterinary applications. It is even possible for the inventive template to be used in a completely different type of application, not involving surgery or drilling into a body, e.g., in carpentry applications, etc. These applications will be known and appreciated by those of ordinary skill in the art, and it is not the inventor's intention to limit the broad disclosure hereof by the particular illustrated embodiment.

(24) According to the embodiment of the invention illustrated in FIG. 2, template 100 is made of any suitable malleable material, which is formed about surface 106 to form a negative impression 112 of surface 106 therein. Template 100 includes a body 114, having a guideway 116 formed therein. Guideway 116 has a first end 118 positioned to open onto the desired location for hole 104 when body 114 is placed in conforming contact with surface 106 and a second end 120 positioned on an exterior surface 122 of body 102. Second end 120 is connected to first end 118 by a passage 124. In a preferred embodiment, passage 124 is substantially linear. Template 100 also includes a stop 126 for limiting the depth of penetration of drill bit 102 into hole 104. Stop 128 may include a shoulder 128 configured to act as a countersink for centering drill bit 102 in guideway 116.

(25) In an alternative embodiment, shown in FIG. 3, body 114 includes a removable portion 130 in which a guideway 132 is formed. Removable portion 130 may be fastened to body 114 by any suitable fastener, such as by at least one clip 134. In this embodiment, the drill bit (not shown in FIG. 2) will be guided by a guiding assembly 136 inserted in guideway 132. Guiding assembly 136 includes an inner piece 138, and an outer piece 140. Inner piece 138 has a substantially linear passage 142 centrally disposed therein for guiding the drill bit, a threaded outer surface 144 and a shoulder 146 which acts as a stop for the drill bit. Outer piece 140 includes a threaded inner surface 148 configured to engage the threads on threaded outer surface 144 of inner piece 138, and a threaded outer surface 150.

(26) Removable portion 130 includes a threaded inner surface 152, having threads configured to engage the threads on outer surface 150 of outer piece 140. In this fashion, outer piece 140 may be fastened in removable portion 130 by screwing it thereinto. Inner piece 138 may then be screwed into outer piece 140 until shoulder 146 reaches the desired position to act as a stop for the drill bit. To assist in determining the depth of inner piece 138 within outer piece 140, indicia 154 may be provided on the outer surface of inner piece 138.

(27) In one embodiment, the threads of outer surface 146 of outer piece 140 and the threads on inner surface 146 preferably have different pitches, so that one of inner piece 138 and outer piece 140 can act as a fine adjustment means for adjusting the depth of guiding assembly 136 in guideway 132, and the other of inner piece 138 and outer piece 140 can act as a coarse adjustment means therefor. In this fashion, it is possible to provide for better adjustment of the depth of guiding assembly 136 in guideway 132, as taught in my co-pending application Ser. No. 10/748,338, filed Dec. 30, 2003, the disclosure of which is hereby incorporated by reference.

(28) Alternatively, it is possible that the two threads could have equal pitches, simply to provide for adjustment of the positioning of shoulder 146 relative to surface 106, and therefore adjust the depth to which the drill bit will drill hole 104.

(29) It is further preferred that inner and outer pieces 138 and 140 be made of a durable material, such as a metal, so that any contact of the drill bit therewith will not result in a widening of passage 142, and the possible mis-alignment of hole 104 from its desired location.

(30) In another embodiment of the invention, body 114 may be formed to include radiographic markers 158. These markers may be removable or permanently affixed, to body 114, as desired. Placing radiographic markers 156, 158 in body 114 and removable portion 130, respectively, offers the benefit of allowing surgical template 100 to act also as a radiographic template, in case further radiographs are useful in preparing subsequent replaceable portions 130.

(31) The inventive method is useful in many applications other than those explicitly described.

(32) For example, the method can be used in stereotaxic surgery, e.g., intracranial surgery, as shown in FIG. 4. In this embodiment, a template, shown generally at 200 in FIG. 4, can be mounted to a patient's head 202 by a frame 204. Template 200 may include a guideway, 206 through a removable portion 208 in template 200, similar to the components of the embodiments illustrated above. Removable portion 208 may also include a stop 210, preferably having tapered shoulders 212 to countersink a drill bit used therein.

(33) In a further embodiment, the method can be used to manufacture a surgical template with a method for the creation of a specific form of a radiographic stent that depends on the dual registration of the upper and lower tooth surfaces into an occlusal wafer that is a standard surgical type of splint. However, in this application a skirt is added to the buccal (lateral) aspects of the surgical splint. Six radiographic markers are placed on the radiographic splint for registration. The patient has the radiographic stent inserted into his teeth and his jaws are wired shut. The patient undergoes a CT scan and, after the scan, the radiographic occlusal splint is removed and scanned separately and then reinserted into the patient's jaws and the teeth are wired shut again into the radiographic splint. The two data sets are then merged by using the radiographic markers as the points of alignment. The result is that the plastic template has the memory of the negative impression of the teeth which is registered in the CT scan data and allows for a replication of the tooth form that would otherwise be unobtainable accurately for the reasons described above. The practitioner then decides on the appropriate trajectory of the surgical fixation screws which is registered and allows the manufacturing process to convert the data of the radiographic template into a surgical template with appropriate trajectories prepared in the correct sites where the surgical fixation screws will be placed via a drilling procedure through metal sleeves to be inserted in the surgical template. The virtual surgical template is sent for manufacturing to produce the surgical template that will be inserted in the patient's mouth for precise placement of surgical screws in the jaw bone via a drilling and insertion procedure that will then allow the placement of an external fixation device and the patient can have his jaws unwired.

(34) Considerable time and cost savings are achieved because the original radiographic stent can be used for both the CT scan and the surgical procedure. The cost of the surgical template is significantly lowered because the time for rapid manufacturing is substantially decreased, allowing more modular templates to be fabricated with less material than would be necessary to create an entire replica of the radiographic splint with trajectories. Greater accuracy is also possible by using the original radiographic splint to fit into the patient's mouth or to remain bolted to the cranium.

(35) This accuracy and cost savings can be applied to a method in which based on a CT scan, a treatment plan can be created whereby the dental implants will be placed and prosthesis inserted all within the same practitioner visit, which saves the patient and practitioner considerable savings in time and costs. In this method, the CT scan is obtained as described above and the surgical template created from the modular portion and the prosthesis which has been fabricated from dental models and based on the stereolithographic model merged with a dental cast to create a laboratory fabricated dental prosthesis. This can be extended to the creation of epthithesis for the replacement of other body parts, e.g., noses, eyes and ears.

(36) The modular portion data can be used to create a temporary bridge or denture type of prosthesis with a modular component. A separate processing of the data creates a modular portion that, instead of having drill trajectories, includes a modular section that can become the attachment element of a dental implant prosthesis, disposed along the same trajectory paths which indicate the planned implant positions. Various means can be utilized to create the implant prosthesis interface of attachment. One method, described by Nobel Biocare, is to utilize a 2-part split shank abutment whereby when a screw is inserted through the dental prosthesis through this 2-part split shank abutment, compensation for the inaccuracy of the fit is achieved between the actual insertion of the implant in the bone and its position relative to the planned prefabricated temporary dental implant prosthesis.

(37) Another method is described based on the slotted slot method of bone plate fixation in which the slot is an inclined curved plane and the screw is half a hemispheric head. In this embodiment, both the superior and inferior aspects of the manufactured modular section have slots. The inferior slot attaches to an adjustable implant abutment and the superior slot has a fixation screw driven through it that inserts into the threaded head of the implant abutment. This dual slotted system allows fixation of the implant prosthesis with compensation for any inaccuracies in the prefabrication of the implant prosthesis. The implant abutment is either a 2-part adjustable threaded member with locking screw adjusted up to the level of the inferior slot, or threads into a threaded interior of the inferior slot similar to a locking plate, with a slit shank or 3-part member inferior aspect of the implant abutment which acts as an intermediate washer.

(38) A further application of the inventive template in distraction osteogenesis is shown in FIG. 5. In this type of application, it is desired to provide for gradual movement and lengthening of a base, through a series of breaks in the base, followed by a slight separation of the broken portions. The base then knits to fill in the small separation, lengthening the base. This process is repeated, as necessary, to lengthen the base to a desired degree.

(39) A template for assisting in distraction osteogenesis is shown in FIG. 5, generally at 300. Template 300 includes two discontiguous sections 302, 304 separated by a variable gap 306, and connected by an adjustment device, such as an Archimedes screw 308. Applying rotation to Archimedes screw 308 imports linear motion to separate sections 302, 304 or bring them closer together, and thereby change the spacing of gap 306. Sections 302, 304 are mounted to respective body sections 310, 312 having a gap 314 therebetween. A modular section 316 may be inserted into gap 306, for example, to steady sections 302, 304 or for use in assisting in taking radiographs of the surrounding body 310, 312 to determine the progress of the procedure. If desired, radiographic makers 318, 320 and 322 may be positioned in sections 302, 304 and modular section 316, respectively, for this purpose.

(40) It will be appreciated that various modifications of the method and apparatus described above can be made without departing from the scope and teachings contained herein. For example, it is possible for the dimensions of the guideway and/or any ferrules placed therein to be varied in diameter to accommodate instruments having different diameters.

(41) It is also possible to utilize only a single sleeved element in lining the guideway so that, for example, in the embodiment of FIG. 3, inner piece .[.136.]. .Iadd.138 .Iaddend.would be optional. The provision of the metal sleeve would permit the use of a durable, for example, metal, outer piece 140 to prevent distortion of the interior of the guideway, and thereby maintain the integrity of the trajectory formed thereby.

(42) Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.