U.S. patent application number 11/068234 was filed with the patent office on 2005-07-07 for device for targeted, catherized delivery of medications.
Invention is credited to Gibbs, David.
Application Number | 20050148939 11/068234 |
Document ID | / |
Family ID | 46281148 |
Filed Date | 2005-07-07 |
United States Patent
Application |
20050148939 |
Kind Code |
A1 |
Gibbs, David |
July 7, 2005 |
Device for targeted, catherized delivery of medications
Abstract
Apparatus and method for catheterized delivery or infusion of
medication and anaesthesia are disclosed. The perforating catheter
is first used to perforate the periodontal ligament and/or the
cortical plate of bone tissue, and is then left in place and used
as a catheter for insertion of a hypodermic needle of smaller gauge
to deliver medication or anaesthesia to a target area. The
perforator is a bevelled needle for drilling into the ligament or
bone tissue. For drilling, the device comprises an adaptor which
transmits the rotational movement from a dental hand piece or the
like to the bevelled needle. A cap is also included for protecting
the bevelled needle during storage of the device. The adaptor may
have a rod which extends axially into the bevelled needle when the
device is assembled for drilling. The rod is used to prevent the
debris resulting from drilling from blocking the passage in the
bevelled needle. As well, the rod reinforces the needle and
maintains the alignment between the perforator and the adaptor for
improved drilling efficiency. An adapter is disclosed which couples
with the catheter once in place easing access to supply medication
to difficult to reach areas.
Inventors: |
Gibbs, David; (Ottawa,
CA) |
Correspondence
Address: |
TEITELBAUM & MACLEAN
1187 BANK STREET, SUITE 201
OTTAWA
ON
K1S 3X7
CA
|
Family ID: |
46281148 |
Appl. No.: |
11/068234 |
Filed: |
March 1, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11068234 |
Mar 1, 2005 |
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10234767 |
Sep 5, 2002 |
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10234767 |
Sep 5, 2002 |
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09420004 |
Oct 18, 1999 |
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6468248 |
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09420004 |
Oct 18, 1999 |
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09255442 |
Feb 22, 1999 |
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09255442 |
Feb 22, 1999 |
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09022314 |
Feb 11, 1998 |
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09022314 |
Feb 11, 1998 |
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08471372 |
Jun 6, 1995 |
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5762639 |
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Current U.S.
Class: |
604/164.01 |
Current CPC
Class: |
A61B 17/3472
20130101 |
Class at
Publication: |
604/164.01 |
International
Class: |
A61M 005/178 |
Claims
1-7. (canceled)
8. A rotatable drilling device for use in injecting a substance,
said rotatable drilling device comprising: a) a rotatable hollow
drill bit, wherein the rotatable hollow drill bit includes a first
hub and a needle having a first outer diameter extending outwardly
from an end of the first hub, the first hub being immovably affixed
to the needle so that when the first hub is rotated, the needle is
rotated with the first hub, wherein the needle has a sharp tip at
an end, wherein the rotatable hollow drill bit has a bore extending
therethrough through which the substance can be introduced into the
bore; and, b) an adapter having a rod at a lower end for removable
insertion in the bore of the rotatable hollow drill bit, wherein
the rod when inserted into the bore extends into and through the
needle for substantially preventing debris from entering the needle
and blocking the bore when wherein the adapter has an upper end for
directly removably coupling with a motorized handpiece and has a
second hub immovably coupled with the rod for directly mating with
the first hub of the rotatable hollow drill bit, so as to impart
rotational motion to the rotatable hollow drill bit when the upper
end of the upper end of the adapter is rotated by the motorized
handpiece.
Description
[0001] This invention is a continuation-in-part parent application
to Ser. No. 09/420,004 filed Oct. 18, 1999 which is a continuation
of patent application to Ser. No. 09/255,442 filed Feb. 22, 1999
which is a continuation of patent application Ser. No. 09/022,314
filed Feb. 11, 1998 which is a continuation of patent application
Ser. No. 08/471,372, now issued as U.S. Pat. No. 5,762,639.
FIELD OF THE INVENTION
[0002] The present invention provides for a simple method and
device for infusing or injecting medication; it is applicable to
medical or dental and the like procedures. More particularly, the
invention is directed to catheterized delivery of anesthesia and
other medication. More particularly still, it is directed to
catheterized delivery of dental anaesthetic to a targeted nerve and
to an apparatus for such delivery.
BACKGROUND OF THE INVENTION
[0003] There are a variety of methods currently in use for
providing local anaesthetic in dentistry. These methods and
apparatuses however all have disadvantages, either being difficult
for practitioners to perform or painful and unpleasant to the
patient.
[0004] An example of a method used currently in dentistry is the
infiltration method, whereby a local anaesthetic solution is
injected into the soft tissue of gingiva. In doing so, the solution
eventually passes through the cortical plate affecting the nerve
bundle entering the tooth. Disadvantages of this method include the
delay of onset of anaesthesia after the injection and, in most
cases, ballooning of the injected tissue. As well, there is an
extended period of time for recovery of the tissue until return to
normal condition.
[0005] Another method which is currently used is the regional block
method whereby an anaesthetic solution is injected locally in
proximity to the nerve trunk as it enters the bone. Disadvantages
of this procedure are that it is extremely difficult to locate the
nerve trunk, there is discomfort to the patient and a delay for the
anaesthetic to take effect. As in the case of the infiltration
method, this method necessitates a long recovery period for tissue
to return to normal.
[0006] At present, two types of apparatus have been used to perform
intra-osseous anaesthesia. These are surgical burs used to
perforate the cortical plate and the villet injectors.
[0007] The use of a surgical bur has disadvantages in that burs are
expensive and they have to be sterilized between uses or a new bur
used each time. In addition, the method is slow, requiring the
attached gingiva and periosteum to be anaesthetized before the
cortical plate is perforated. The villet injector is an apparatus
that serves both as a perforator and injector. It uses specially
designed needles rotated by a conventional dental motor. A
disadvantage of this device is that the needle often becomes
clogged with pulverized bone which obstructs the passage in the
needle and prevents injection of the anaesthetic solution. It is
generally difficult to remove the clogging material from the needle
and often the use of a second needle is necessary. Other
disadvantages of this method include the initial capital cost of
the instrument purchase, and the cost of the needles which are
somewhat expensive. In addition, the design of the instrument makes
access to various parts of the mouth difficult and sometimes
impossible.
[0008] Intra-osseous and targeted root-canal nerve anaesthesia have
not become popular for the reason that there has not been a
practical technique of making the injections successfully. For
example, there has been a general belief that this method is
radical and to be restored to only if nerve block and infiltration
anaesthetic do not accomplish the desired result. However,
intra-osseous and targeted injections produce positive, more
profound anaesthesia and could be made with less pain than either
of the other types according to the present invention.
[0009] Targeted anaesthesia has several advantages over prior art
nerve block or infiltration methods. There is no feeling of
numbness in the tongue, cheek, or lips during or after the
injection and there is no after-pain. The anaesthetic is profound
and acts immediately alleviating the necessity of waiting for the
anaesthetic to take effect as with the nerve block and infiltration
methods. Furthermore, as only a few drop, of anaesthetic are
injected, there is no feeling of faintness or increasing of the
pulse rate.
[0010] To achieve targeted anaesthesia one must gain access, it
intra-osseous, to the cancellous bone by going through the cortical
layer; or to the bottom of the tooth, if root-canal targeted
anaesthesia is desired. Because of instant anaesthesia and profound
pulpal anaesthesia, there is a much greater control over the region
one wishes to anaesthetize, resulting in a much smaller dose of
anaesthetic; as well as, of course, other medication, where
applicable.
[0011] U.S. Pat. No. 5,173,050 (Dillon) discloses a dental
apparatus for perforating the cortical plate of human maxillary and
mandibular bones. The apparatus of Dillon comprises a metal needle
moulded into a plastic shank. The shank is being formed with means
for cooperation with a dental hand piece for transmitting the
rotational movement to the needle. The needle used for drilling is
solid and has a sharp bevelled free end. The apparatus described by
Dillon is disposable.
[0012] However, the device disclosed in Dillon's patent cannot be
used as a catheter for injecting anaesthetic by inserting a
hypodermic needle through the drilling needle. As well, the device
disclosed by Dillon is not provided with means for blocking entry
of bone debris into the needle passageway. In addition, the direct
connection between the hand piece and the perforator does not
provide for a safe and reliable barrier against bacteria passing
from the needle to the hand piece.
[0013] U.S. Pat. No. 3,534,476 (Winters) discloses a drilling and
filling root canal apparatus. The drilling is performed by a drill
having a central bore. The depth of the root canal is determined in
advance and a stop is placed on the drill to limit the depth of
drilling. The device is provided with a flexible rod which is
pushed into the root canal so that the drill is directed along this
road to follow the contour of the canal so that resulting bore will
have an uniform diameter which is free of shoulders or ledges. The
apparatus disclosed by winters is concerned with enlarging the root
canal after the nerve has been extracted. This apparatus is not
used for injecting medication in close proximity to a targeted area
for treatment or anaesthetic.
[0014] U.S. Pat. No. 4,944,677 (Alexandre) discloses a smooth
hollow needle with a bevelled point for drilling a hole into the
jawbone near the apex of the tooth to be anaesthetized. Thereafter,
the drilling device 13 removed from the jaw, and a hypodermic
needle of substantially the same gauge is inserted into the hole
and anaesthesia is injected. Thus, there is no cathetized delivery
of medication, with the attendant disadvantage that the pre-drilled
hole may be difficult to locate when inserting the hypodermic
needle.
[0015] One significantly older United States patent that is
discussed by Alexandre (above) is U.S. Pat. No. 2,317,648
(Siqveland) granted in 1943. In addition to the disadvantage
mentioned by Alexyandre, the fact that Siqveland teaches use of
threaded sleeve which penetrates the bone during drilling and is
left (screwed) in the bone to serve as a guide for insertion of the
actual injection needle. Due to the cost of such a device, it
cannot be made disposable; but more importantly, for the threaded
sleeve to be securely fastened in the bone it would have to rotate
at a much slower speed than the drill (as in Siqveland) or the
drilling catheter (as in the present invention).
[0016] Several other U.S. patents such as U.S. Pat. No. 5,332,398
in the name of Miller, and U.S. Pat. No. 4,969,870 in the name of
Kramer have followed the teaching of Siqveland wherein the catheter
is at least somewhere along its outer periphery threaded, or
designed to implant itself fixedly within the bone it is being
disposed in; Furthermore, designs of this type require slowly
turning the drilling shaft (or catheter sleeve) into the bone until
resistance is encountered at which point the catheter is determined
to be in place.
[0017] Over the past 50 year or so, and at least since the
invention of siqveland, patented in 1943, devices and processes for
intraosseous anesthesia have been developed and refined. However,
heretofore, no other inventors have provides a useful, workable
convenient and inexpensive solution that affords all of the
benefits provided by this invention. For example, non of the prior
art devices allow a motorized handpiece to drive a small
intraosseous catheter/drill having a rod/drill therein wherein the
device can be placed by drilling at high or slower speeds and
removed by simple withdrawal by pulling out the catheter. Most of
the effort in this field had been directed toward longer term
delivery of medication wherein the catheters have had some means of
latching into the bone for more permanent placement. Furthermore,
the instant invention does not suffer from may of the drawbacks of
inserting the needle/drill into the bore being cut by the end tip
of the drill, since the outside walls of the needle/drill are of a
uniform diameter and non-varying. With the long-felt want of this
device, in the past decade in view of the many publications in this
field, no such optimal device has been suggested.
[0018] In contrast to the prior art, the instant invention provides
a dual purpose perforator which includes a needle/sleeve that
serves as a relatively high-speed drill bit and which serves as a
catheter chat is removable by withdrawing it by pulling it out, and
not by unscrewing it. The perforator has a substantially uniform
outer diameter and has a smooth non-threaded outer surface;
preferably, the catheter is a larger gauge needle than the
removable rod contained within which may also be in the form of a
beveled needle for preventing bone, skin and debris from entering
the catheter during entry into the bone. A hypodermic needle of
same gauge as the rod is later placed in the catheter after the rod
is removed.
[0019] Advantageously, the beveled end of the rod assists the
cutting of the opening into the bone along with the perforator as
they are both rotated by the dental hand piece they are coupled
therewith.
[0020] To our knowledge, there are no prior art patents, which
teach the use of a perforator having a hypodermic needle-like
cutting tool wherein the outer diameter is uniform allowing both
precise cutting of a small hole, and allowing easy removal by
simply pulling the device out without unthreading, wherein the
perforator has an upper end adapted to be connected to a motorized
dental hand piece; and, wherein the perforator has a rod therein
which turns with the perforator needle-like cutting tool assisting
in preventing debris from entering the perforator; and wherein the
rod is itself a needle-like cutting tool assisting in the cutting
of the opening.
[0021] To our knowledge, aside from the parent patent application,
now issued as U.S. Pat. No. 5,332,398 and U.S. Pat. No. 5,779,708
in the name of Wu, issued Jul. 14, 1998 there are no prior art
patents, which teach the use of a perforator having a hypodermic
needle-like cutting tool wherein the outer diameter is uniform
allowing both precise cutting of a small hole, and allowing easy
removal by simply pulling the device out without unthreading,
wherein the perforator has an upper end adapted to be connected to
a motorized dental hand piece; and, wherein the perforator has a
rod therein which turns with the perforator needle-like cutting
tool assisting in preventing debris from entering the perforator:
and wherein the perforator serves as a catheter for accommodating a
hypodermic needle having a same outer diameter as the rod, after
the catheter is inserted into the bone.
[0022] It is the belief of the inventor, that this novel method and
combination of elements will eventually change the way in which
many dentists infuse medication and local anesthesia.
[0023] Unlike the prior art catheters the catheter drill of the
instant invention will not bind or increase its resistance against
the drilling hand piece as it is drilling into the bone. The
uniform outer diameter allows the drill/needle to cut without
binding and acting as a self-tapping hollow screw.
[0024] In addition to this novel way of performing dentistry, there
is preferred embodiment of this invention which facilitates use of
the device in more difficult to access areas of a patient's mouth,
for example, when it is required to access molars in the back of
the mouth. In order to reach these otherwise difficult to reach
areas with medication, after the catheter drill resides in its
targeted area, an adapter for injecting fluid al a right angle to
the longitudinal axis of the catheter drill is provided.
[0025] Furthermore, this adapter can be used or embodiments thereof
are provided which obviate the use of a syringe equipped with a
hypodermic needle.
[0026] Advantageously, this invention provides an adapter for
coupling with the interosseous catheter drill that allows fluid to
be injected without having to locate the tip of a hypodermic needle
into the catheter, which can be difficult.
SUMMARY OF THE INVENTION
[0027] The present invention endeavours to mitigate the problems
and disadvantages of delivering dental anaesthetic encountered with
the prior art methods and devices.
[0028] The present invention provides a perforator having a central
passage, which perforator then remains in place as a catheter for
allowing a hypodermic needle to be inserted through the passage to
deliver the desired medication. The preferred apparatus is provided
with means for obstructing the entry of debris in the perforator's
passage.
[0029] In accordance with the invention, there is provided a device
for perforating the periodontal ligaments, cortical plate or small
bones, and the like and for injecting substances at a predetermined
site, comprising:
[0030] perforator for drilling a hole into the ligament, bone or
tissue, wherein said perforator is provided with an inner passage
to form a catheter adapted to remain in the hole for directing a
hypodermic needle to the predetermined site; and
[0031] an adapter for coupling to an end of the perforator and for
latching a latching-type powered dental handpiece thereto and for
transmitting rotational movement from the powered dental handpeice
to said perforator, the perforator having a drilling needle
extending from an end thereof, the drilling needle having a uniform
outer diameter and a smooth non-varying outer surface allowing
removal once inserted into the periodontal ligaments, cortical
plate or small bones and the like by withdrawing the needle by
pulling backwards along a line defined by a longitudinal axis of
the inserted drilling needle; the adapter for coupling with the
perforator in a locking engagement such that rotational motion
imparted to the adapter, rotates the perforator when the adapter is
coupled with the perforator, the adapter having an upper end having
a driving shank extending along a rotational axis for removably
engaging the powered dental hand tool, the adapter having a rod
sized to be accommodated within the perforator and sized to fit
into a passage in said drilling needle at a lower end thereof.
[0032] In a further aspect, the rotary drive shaft comprises an
axial rod adapted to be inserted into the hollow drilling catheter
when engaging it.
[0033] According to another aspect of the present invention, there
is provided a device for perforating the periodontal ligaments,
cortical plate of small bones, and the like, for injecting
substances at a predetermined site, comprising: a
[0034] perforator for drilling a hole into the ligament, bone or
tissue, wherein said perforator is provided with an inner passage
to form a catheter adapted co remain in the hole perforated for
directing a hypodermic needle to said predetermined site, and an
adaptor for latching in a latching-type powered dental handpiece
for transmitting rotational movement to said perforator, the
adapter having a rod at an end thereof sized to be disposed within
the perforator inner passage.
[0035] The catheterized intra-osseous delivery system of the
present invention comprises a perforator with a bevelled drilling
needle that is used as a drill and a catheter. The needle is
attached at one end to a plastic or metal body. For drilling, the
body is attached to a matching adaptor provided with a driving
shank which is rotated by a conventional contra angle or straight
dental hand piece. Then, the perforator is used as a catheter,
whereby a hypodermic needle is inserted through the drilling needle
without losing access to the already perforated bone.
[0036] In the preferred form of the invention the apparatus is
disposable. Before disposal, the perforator receives a cap over the
needle for protection against accidental contamination of
environment.
[0037] The present invention also provides a method of medical
treatment, comprising the steps of: inserting a catheter, at a
point in the gingival sulcus between outer tooth surface and
marginal gingiva, or through gingiva and cortical plate, to a
predetermined depth; and injecting medication or anaesthesia
through said catheter.
[0038] Advantageously, the system of the present invention provide
users with a more secure and less painful method and device for
direct access for injecting medication to a target area into the
cortical plate of the bone.
[0039] In addition, the system facilitates and adds a level of
security previously unavailable for the anaesthetic in that it has
a sure and immediate effect.
[0040] Another advantage of this system is that it provides
benefits to the dentists by facilitating the use of a low cost,
disposable device.
[0041] Still another advantage of this invention is that the risk
of contamination is lower than with the current devices. This is
because the device is disposable and because the risk of the dental
equipment used with the device of the invention becoming
contaminated is low.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] These and other features of the invention will become more
apparent from the following description of the preferred
embodiments, in which reference is made to the appended drawings,
wherein:
[0043] FIG. 1 illustrates an exploded view of the device showing
the component parts and their inter-relationship;
[0044] FIG. 2A illustrates the device assembled for drilling;
[0045] FIG. 2B illustrated a longitudinal cross-section through the
device illustrated in FIG. 2A, taken along line A-A of FIG. 2A;
[0046] FIG. 3 shows a detailed view of the area marked on FIG.
2B;
[0047] FIG. 3B shows a detailed view of the rod-needle inserted in
the perforator cutting/drilling-needle inserted in a different
orientation than in FIG. 3;
[0048] FIG. 4 is a cross-sectional view of the body of the
perforator taken along lines B-B of FIG. 2;
[0049] FIG. 5 is a cross-sectional view of the adaptor body;
[0050] FIG. 6 is a cross-sectional view of the cap;
[0051] FIGS. 7A-7C illustrate the method according to the
invention, FIG. 7A shows the device drilling, in the bone tissue;
FIG. 7B shows the perforator inserted into the bone tissue and the
adaptor de-coupled; and FIG. 7C shows the perforator inserted into
the bone tissue as a catheter and a hypodermic needle set: for
delivering an injection;
[0052] FIG. 8 illustrates another embodiment of the invention;
[0053] FIG. 9 illustrates an alternative method of delivery
medication to treat a root-canal nerve;
[0054] FIG. 10 illustrates from a plan view the point of catheter
insertion for the alternative method shown in FIG. 9;
[0055] FIG. 11 is a perspective, exploded view of the parts of an
alternative embodiment of the invention wherein the catheter and
adapter can be temporarily locked while drilling occurs;
[0056] FIG. 12 is a sectional elevation of the same catheter
assembly; and,
[0057] FIG. 13 is a plane view of an additional, optional component
of the assembly.
[0058] FIG. 14 is a cross sectional view of an alternative
preferred embodiment of a catheter wherein the hollow needle
protrudes both ends of the hub;
[0059] FIG. 15 is a cross-sectional view of an adapter coupled in
locked sealing engagement with the catheter shown in FIG. 14;
and,
[0060] FIG. 16 is an alternative embodiment of the adapter having a
syringe at one end.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0061] FIG. 1 illustrates an exploded view of the device showing
the component parts and their inter-relationship. The device
comprises a perforator 1, an adaptor 3 and a cap 5.
[0062] The perforator 1 has a bevelled drilling needle 7 which is
used both as a drill and a catheter. Needle 7 is bevelled at both
ends, as better shown on FIG. 2B. The first end 9 is formed as a
drilling tip in that it has cutting teeth along the edge, as shown
in FIG. 3. The second end 11 is bevelled for receiving and
directing the needle of a hypodermic syringe and for easy coupling
with the adaptor 3, as will be seen later.
[0063] A flange 13 is fixed on the needle about the second end 11,
so that the needle passes along the geometrical axis of the flange
13. The flange 13 is manufactured or moulded of a plastic or other
material, and it has a generally cylindrical outer shape. This
shape is preferred as the flange 13 rotates together with the
needle 7 for drilling. Variations of the shape illustrated in the
attached drawings may also be contemplated.
[0064] The flange 13 is adapted for receiving cap 5 at one end and
for coupling with the adaptor 3 at the other end. As an example, a
collar 15 may be provided on the flange 13 so that the cap 5 holds
over the collar 15 when pressed. The cap 5 is needed to protect and
cover the tip 9 of the needle 7 before use and when the device is
disposed of.
[0065] For ease of manipulation the internal diameter of the cap 5
and the external diameter of the collar 15 should be as large as is
reasonable and preferably between 10 to 20 times greater than the
diameter of the needle 7. Another advantage of the collar 15 is
that it provides a stop to limit the depths of penetration of the
needle 7 (the depth of penetration of the needle 7 is, therefore,
termed the drilling length, as opposed to the remaining length of
the needle 7, which is termed the attachment length). The flange 13
is shaped to form an inner axial shaft 17 projecting from the
centre of the collar 15, and a female connector 19 for coupling
with a corresponding male connector provided in the adaptor 3.
[0066] The coupling between the perforator and the adaptor is
illustrated on FIGS. 2B, 4 and 5. FIG. 2B shows a longitudinal
section of a female connector 19 provided in the flange 13 and a
male connector 21 provided in the adaptor 3. FIG. 4 illustrates a
cross-section of an exemplary female connector 19, while FIG. 5
shows a cross-section of the corresponding male connector 21. The
male connector is provided with radial ribs 23, extending towards
the centre but not meeting to leave room for the central shaft 17,
while corresponding grooves 25 are provided in the female
connector, alternating with islands 20. The female connector is
also formed with a clearance ring 22 for accommodating the
thickness of the body 29 of the adaptor.
[0067] The tubular shaft 17 forms a reinforced passage for drilling
needle 7. The shaft also provides enough contact surface between
the drilling needle and the body to ensure that these two parts
rotate together during drilling. As could be seen on FIG. 28, end
11 of the needle is bevelled and extends a little over the shaft
17, but there is a clearance between the tip of end 11 and the male
connector when the device is assembled for drilling.
[0068] When rotated, the drilling needle 7 penetrates in the bone
tissue through gingiva or ligament and drills a hole with the
cutting tip 9. The perforator 1 may remain in place as a catheter,
with the drilling needle inserted into the bone. Then, a hypodermic
needle may be introduced through the passage of drilling needle 7
to insect a medicament directly into the bone. Therefore, the
drilling needle 7 is selected to have a wide enough passage for
allowing a hypodermic needle with a smaller gauge to be inserted
through needle 7.
[0069] The adaptor 3 has several important functions. Firstly, the
adaptor conveys the rotational movement from a dental hand piece or
the like to the perforator. As well, the adaptor is provided with
means for blocking bone debris for entering into the syringe
passage and also aligns and reinforces the needle 7 during
drilling. In the preferred embodiment of this invention is it
important that the adapter be coupled with the dental hand tool
which dives the adapter about its longitudinal axis. It is also
important that the adapter conveys its rotational movement from the
dental hand piece to the perforator 3. By providing this novel
arrangement, after the perforator is inserted into the bone, where
it is to remain, all that is required is that the adapter with the
dental handpiece be removed from the perforator. Hence the order of
dental hand piece driving the adapter including the rod 27 which in
turn drives the perforator and its drilling needle is important in
the preferred embodiment.
[0070] The adaptor includes a rod 27, a body 29 and a shank 31.
[0071] Body 29 includes male connector 21 which is formed, as
indicated above, with longitudinal ribs 23 which couple with
grooves 25 of the female connector 19 for driving needle 7. The
shank 31 extends along the axis of the adaptor and is formed with a
joint 33 for attachment with a contra-angle or straight hand piece.
The shank 31 has a groove 35 and a cut-out 31 to fix the shank in
place in the known manner. Generally, the shank transmits to the
needle 7 the rotational movement from the hand piece.
[0072] The shank 31 also acts as a barrier for contamination, at it
is generally thought that bacteria is reluctant to change
direction, and there are a plurality of 90.degree. angles between
the tip 9 of drilling needle 7 and the joint 33.
[0073] The rod 27 has the diameter and length selected in
accordance with the size of needle 7. The rod 27 is fixed in the
geometrical centre of body 29 so as to readily penetrate into the
hollow passage of the needle, when the device is assembled for
drilling. When the rod 27 is inserted within the needle passage, it
advances through the length of the needle up to the bevelled end,
as shown on FIGS. 2A and 3 and 3B in dotted lines. In this way, the
debris from drilling cannot penetrate to block the needle passage.
In addition, the rod gives additional rigidicy, strength and
alignment to needle 7 during drilling. The rod also advances
through the a portion of the shank as is illustrated in FIG. 2B in
dotted lines. Furthermore, the rod which can itself be in the form
of a needle similar to the hypodermic needle for delivery of
medication, wherein the rod end is sharp and pointed, to assist in
the drilling process. By using standard hypodermic needle tubing
for the rod, the cost of the device can be minimized while gaining
the benefit of the cutting tip. In manufacture, the cutting tip of
the drilling needle 7 and the rod can be cut at the same time to a
desired length.
[0074] FIG. 8 illustrates an alternative embodiment of the present
invention. In this variant, body 13 is provided with an internal
thread while body 29 is provided with a matching external thread.
By threading one to the other and using the central rod 27 to align
the two bodies together, the perforator could be driven by the hand
piece in a similar manner as in the variant disclosed above. Of
course, the thread is going in an opposite direction to the
direction of rotation of the device for avoiding disconnection of
the two bodies.
[0075] An alternative method of targeted delivery is shown in FIGS.
9 and 10. The perforator 7 is inserted at a point 30 between teeth,
parallel to the tooth 31 in treatment, and penetrates through
gingival sulcus 32 and ligament 33 to a depth near the entry of the
nerve, artery and vein bundle 34 through the bone 35
[0076] and into the tooth-root canal 36. This method of targeted
delivery, say, of anaesthesia is suitable, where perforating
vertical to the tooth through gingiva and cortical bone is not
convenient or possible; as in the case of rear molars.
[0077] There are a variety of ways chat this invention can be
devised but the end result is to perform catheterized intra-osseous
delivery system.
[0078] The device of this invention operates as follows:
[0079] First, a site for the injection is selected by the
practitioner. The gingiva over the injection side is disinfected
and topically anaesthetized. A small amount of anaesthetic solution
is injected until blanching of the tissue, and this will
anaesthetize the gingiva and the periosteum. The following
operations are illustrated in FIGS. 7A, 7B and 7C, and FIGS. 9 and
10.
[0080] As can be seen in FIG. 7A, the bevelled end 9 of the needle
7 is placed against the gingiva and shank 31 is attached with joint
33 to a contra angle or to a straight dental hand piece. The
adaptor and perforator are coupled for drilling.
[0081] The perforator should be held perpendicular to the cortical
plate, or if not possible or convenient, it should be held vertical
and parallel to the long axis of the tooth as shown in FIG. 9,
having been inserted between teeth as shown in FIG. 10. The
perforator is then operated in small bursts of rotation from the
hand piece until resistance is no longer felt, as is well known to
dentists.
[0082] Next, the adaptor 3 is removed from the engagement with
perforator 1 by applying pressure to the body 13 with the fingers
thus keeping the needle 7 in the perforated cortical plate. This is
shown in FIG. 7B.
[0083] The presence of the needle 7 in the cortical plate, or down
the side of the tooth as in FIG. 9, allows an injection to be made
without complicated manoeuvres to find the perforation in the case
of floating gingiva or the free or marginal gingiva. FIG. 7C
illustrates the next step, namely how the injection needle is
inserted through the perforator 1 for delivering the anaesthetic
solution required.
[0084] The last step is to remove the perforator 1 from the
cortical plate and reinstall the cover cap 5 over the needle 7,
then insert the adaptor to the perforator making the unit complete
and disposable. The cap 5 provides a means whereby the apparatus
may be removed from the dental hand piece without any risk of the
user being in contact with body fluids which will be present on the
needle after use. This is extremely important particularly since
there may be a risk of contacting Aids or Hepatitis should the user
accidentally prick a finger with the needle. It is therefore
desirable that the cap should be of a hard or rigid rubber or
plastic material not easily penetrated by the needle.
[0085] Referring to FIGS. 11 and 12, the catheter assembly
comprises a disposable contamination protective cap or housing 10
which, in the assembled state, surrounds a hollow drilling needle
or catheter 11, preferably of stainless steel, having a drilling
tip 12 and a non-drilling end with an outwardly flaring end portion
13. The end portion is fixed, and preferably molded, within a
cylindrical driven flange 14 which is made of plastic material and
is disposable along with the needle.
[0086] The flange is adapted to be driven by the drive means
including a drive flange 16 which has a periphery matching radius
of the flange 14, and which is integrally formed with a shaft 17
suitably dimensioned to fit into the handpiece of a standard dental
drill; the diameter of this shaft being preferably between 2.27 and
2.45 mm. Parts 16 and 17 may either be metal or plastic, and will
also normally be considered disposable. The flange 16 and shaft 17
have an axial bore into which is secured a rod 20 having a cutting
tip (not shown) which projects from the flange 17 by an amount
equivalent to the main drilling length of the needle 11, and which
prevents the needle from becoming blocked with debris during
operation.
[0087] The driven flange 14 and the drive flange 16 each have a
longitudinal groove, indicated respectively at 14a, 16a. When all
the parts are assembled, these grooves are occupied by a
longitudinal internal rib 21 in the cylindrical wall of the a
locking sleeve 22. This is a thin-walled, disposable cap-type part,
the cylindrical wall of which is capable of substantially enclosing
the two flanges 14 and 16, and having an upper end flange 22a
which, when the sleeve is fully engaged with the two flanges 14 and
16, rests against the upper surface of the flange 16. The sleeve 22
serves to hold the flanges together, as well as transmitting rotary
motion from the drive to the driven flange. The sleeve is a push
fit within the housing 10.
[0088] The parts are sold in the assembled condition as shown in
FIG. 12. For use the housing 10 is removed, the shaft 17 is fitted
into a drilling machine, and a drilling proceeds in the normal way.
After drilling, the shaft 17 with flange 16, and rod 20 and sleeve
22, are removed from the flange 14, and anaesthetic is then
introduced through the needle 11 which then acts as a catheter.
[0089] All parts of the assembly are disposable after use.
[0090] FIG. 13 shows a further feature of this embodiment, namely a
holder 30 which comprises a rod 30a fixed at one end to part
circular clip portion 30b which is formed to encircle a
circumferentially grooved central area 14b of the flange 14. This
holder may be placed in position to hold the flange 14 after
drilling has taken place, with its rod 30a lying along side of the
patients mouth and preventing undesirable movement of the flange 14
during the injection step.
[0091] In summary, this invention provides particular advantages
not suggested in prior art devices. The provision of an adapter
piece having a rod at a lower end, a shaft at an upper end for
coupling with a motorized dental handpeice, and an intermediate hub
disposed between the rod and the shaft wherein the hub has means
for locking with a catheter having a drilling needle provides
numerous advantages. The drilling needle has a uniform outer
diameter and can be withdrawn by simply pulling it out. The adapter
is designed to prevent the drilling needle from becoming blocked
during drilling and is designed to turn the drilling needle when
powered by the handpeice. More importantly, when the catheter has
drilled the hole in the bone, the adapter can be removed with the
handtool leaving the catheter in place.
[0092] Numerous other embodiments can be envisaged without
departing from the spirit and scope of the invention. For example,
the end of the rod can be provided with a cutting tip assisting the
cutting needle in drilling the hole. Furthermore, the rod itself
can be a square rod for engaging a complementary recess in the
catheter opening. This embodiment would allow the device to
function even if the rod was partially extracted during the
drilling of the hole as any portion of the square rod could be used
to drive the cutting needle.
[0093] Although the device described heretofore and shown in the
figures is performs satisfactorily, and locating and disposing the
drill into the bone at a desired location is relatively simple, it
would be advantageous to provide easier access to the catheter once
in place about the molars and teeth in general at the back of a
patient's mouth. Locating the opening at the top of the hub, i.e.
the opening of the drilling needle with the hypodermic needle can
be an onerous task. It would be preferred to connect a sleeve or
tube to the top of the drilling needle so that a medication supply
could be provided thereto.
[0094] Turning now to FIGS. 14 and 15, the catheter assembly
comprises a hollow drilling needle or catheter 140, having a lower
pointed end 141a and an upper pointed end 141b, preferably of
stainless steel; the lower end 141 a is designed to cut as it
rotates and the non-drilling upper pointed end serves to puncture a
rubber membrane 152 of an adapter 151. As in previous embodiments,
a rod 143 and upper housing 145 are adapted to fit over and within
the drilling needle 140. The adapter 151 has lockable clips 154a
and 154b for locking into engagement with the recesses 146 within
the hub 148. The adapter conveniently serves as an extension that
extends the length and the size and angle of the access port of the
catheter when in place so that inserting the hypodermic needle 158
containing medication becomes much simpler. Of course the body of
the adapter 151 can be rigid. In another embodiment not shown a
flexible adapter is provided.
[0095] The adapter shown in FIG. 15 is used as an extension
passage, for extending the length and orientation of the catheter.
However, the adapter shown in FIG. 16 serves as both an extension
of the catheter and as a syringe, obviating the requirement to
provide a hypodermic needle.
[0096] Turning now to FIG. 16 a drilling needle 160 is shown having
a hub 162 from which a piercing upper needle 164 extends at an
upper end. A clip 166 holds the hub in place as is shown in FIG. 17
which is a front end view of the device shown FIG. 16. A syringe
170 housing medication includes a plunger 172 includes the clip
which engages the hub, mating the two together. This is clipped on
after the drilling needle has been inserted, and the rod
removed.
* * * * *