U.S. patent application number 11/644847 was filed with the patent office on 2007-05-10 for combination distraction dental implant and method of use.
Invention is credited to Suzanne Stucki-McCormick.
Application Number | 20070105068 11/644847 |
Document ID | / |
Family ID | 25388330 |
Filed Date | 2007-05-10 |
United States Patent
Application |
20070105068 |
Kind Code |
A1 |
Stucki-McCormick; Suzanne |
May 10, 2007 |
Combination distraction dental implant and method of use
Abstract
A combination dental implant/prosthetic support and distractor
for facilitating distraction osteogenesis comprises a basically
cylindrical shaft having a set of threads on the outside surface
and a smooth, distal tip which bears against the bone of the jaw of
the patient. Rotation of the device in the mouth of the patient,
after a suitable surgical cut is made, causes the adjacent tissue
to move or ride up the screw threads to create space between the
cut jaw segment and the balance of the jaw tissue. This space is
then filled in by distraction osteogenesis. The implant/distractor
is left in-situ, after the distraction is finished, for securement
thereto of a dental prosthetic, either a bridge or crown. In an
embodiment of the invention, a flat disc is placed in the blind
bore drilled into the jaw such that the distal tip of the shaft of
the combined implant/distractor, will bear against it. A protective
cap and/or collar can be provided, suitable shaped, to protect the
shaft/gum line from bacterial attack. Also, the shaft may be
provided with an internal passageway and one or more radially
extending branches. Growth-enhancing material can be passed through
the passageway and branches to promote bone development and
recovery. In another embodiment, a coronal member is provided,
extra-osseously, to facilitate the distraction osteogenesis
process. In one version of the device, fluting is provided to the
exterior surface of the shaft so that bone growth is enhanced at
that intersection. Also, the shaft can be provided with a flat disc
at its head to reduce rocking of the device in the mouth.
Inventors: |
Stucki-McCormick; Suzanne;
(New York, NY) |
Correspondence
Address: |
KENYON & KENYON LLP
ONE BROADWAY
NEW YORK
NY
10004
US
|
Family ID: |
25388330 |
Appl. No.: |
11/644847 |
Filed: |
December 21, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10974613 |
Oct 27, 2004 |
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11644847 |
Dec 21, 2006 |
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10378761 |
Mar 3, 2003 |
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10974613 |
Oct 27, 2004 |
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09353178 |
Jul 14, 1999 |
6537070 |
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10378761 |
Mar 3, 2003 |
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08886078 |
Jul 2, 1997 |
5961329 |
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09353178 |
Jul 14, 1999 |
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Current U.S.
Class: |
433/173 |
Current CPC
Class: |
A61B 17/666 20130101;
A61B 17/864 20130101; A61C 8/0006 20130101; A61B 17/663 20130101;
A61C 8/0018 20130101; A61B 17/8685 20130101 |
Class at
Publication: |
433/173 |
International
Class: |
A61C 8/00 20060101
A61C008/00 |
Claims
1-59. (canceled)
60. Apparatus for installing a dental prosthesis in the jaw of a
patient comprising: a) a dental implant comprising an incremental
distraction mechanism having a proximal end and a distal end and
provided with means for selectively and incrementally moving a
sectioned jaw portion in a direction from the distal end to the
proximal end of the distraction mechanism, thereby inducing
distraction osteogenesis; and b) a prosthesis support means
disposed on the proximal end of the distraction mechanism for
securing said dental prosthesis, wherein said incremental
distraction mechanism and said prosthesis support means are
integrated into a single system.
61. The apparatus as claimed in claim 60, wherein said dental
prosthesis is a crown or bridge.
62. The apparatus as claimed in claim 60, wherein said prosthesis
support means comprises a dental implant having a center bore with
internal screw threads which matingly engage with external screw
threads of said dental prosthesis.
63. The apparatus as claimed in claim 60, wherein said incremental
distraction mechanism comprises a longitudinal shaft having a
threaded section and a smooth, distal tip.
64. The apparatus as claimed in claim 63, wherein said threaded
section is provided with incremental rotation enabling means for
selectively, incrementally rotating said threaded section.
65. The apparatus as claimed in claim 64, wherein said incremental
rotation enabling means comprises a hex-shaped head of said
longitudinal shaft.
66. The apparatus as claimed in claim 64, wherein said incremental
rotation enabling means comprises a hex-shaped bore of said
longitudinal shaft.
67. A combination dental implant-distraction device comprising: an
expansion component having a proximal end and a distal end which
comprises, a threaded longitudinal shaft displaced between the
proximal and distal ends, a distal tip distal to the shaft, and a
prosthesis support means displaced at the proximal end of the
expansion component for securing a dental prosthesis, wherein the
distal tip has a narrower diameter than the shaft.
68. The device of claim 67, wherein the device further comprises a
hollow coronal component, wherein the hollow coronal component has
internal threads which engage the threaded longitudinal cylindrical
shaft, and a means for engaging a surgically sectioned jaw.
69. The device of claim 68, wherein the hollow coronal component is
located extra-osseously.
70. The device of claim 69, wherein the means for engaging the
surgically sectioned jaw comprises an extended spike which projects
from the coronal component into a gum lining of the surgically
sectioned jaw.
71. The device of claim 68, wherein the hollow coronal component is
located intra-osseously.
72. The device of claim 67, wherein the head has a central,
hex-shaped blind bore which cooperates with a turning key to
facilitate incremental rotation of the mechanical component.
73. The device of claim 67, wherein the prosthesis support means
comprises a center bore through the head and the shaft with
internal screw threads, which matingly engage with external screw
threads of a dental prosthesis.
74. The device of claim 73, wherein the dental prosthesis is a
crown or bridge.
75. The device of claim 67, which further comprises a cap adapted
to sit and frictionally fit over the device.
76. The combination dental implant-distraction devices of claim 67,
further comprising an anti-rotational groove in the longitudinal
cylindrical shaft.
77. The device of claim 67, further comprising a center bore
through the head and shaft, which communicates with a plurality of
radially extending branches which exit the outside circumferential
surface of the device.
Description
[0001] This invention is a continuation-in-part of my prior patent
application Ser. No. 08/886,078 filed Jul. 2, 1997 entitled
Combination Distraction Dental Implant and Method of Use. That
application which is reproduced in its entirety hereinafter is
directed to an in situ combination distraction and dental implant
system comprising an apical member having a top surface, a coronal
member comprising internal threads and a bottom surface with the
bottom surface of the coronal member facing the top surface of the
apical member and a rod like connecting distraction member
comprising a first set of external threads matingly engageable with
the internal threads of the coronal member facilitating mechanical
incremental rotation of the connection and distraction member with
respect to the coronal member such that incremental rotation of the
connecting and distraction member causes the coronal member to
vertically separate from the apical member and create a
correspondingly sized vertical gap between the top and bottom
surfaces for distraction osteogenesis.
[0002] That system creates osteogenesis in the jaw of a dental
patient by surgically cutting a section of the jaw so that the cut
section attaches to the coronal member, and as the coronal member
separates from the apical member, the jaw segment which has been
sectioned slowly moves away from the remaining jaw section so that
osteogenesis begins to occur filling the gap between the separated
tissue members. The movable segmented jaw section generally moves
upwardly to raise the bone and gum level line (for the bottom jaw)
to enhance the support structure for a dental implant to be placed
in the jaw of the dental patient. By allowing the jaw tissue of the
jaw segment (which is movable with respect to the remainder of the
jaw) to adhere to the coronal member and move the coronal member
vertically, not rotationally, with respect to the distraction
member, tissue tear between the movable jaw segment and the coronal
member is materially eliminated.
[0003] The present invention recognizes that distraction
osteogenesis may be generated more simply by merely providing a
combination distraction and dental implant system in which the
system only comprises a combination dental distraction and implant
device which comprises a head and a shaft portion. The shaft,
preferably basically cylindrical, comprises a threaded,
longitudinal shank section and a smooth-wall distal-end section.
The distraction and implant device is engaged in the jaw of the
patient in a conventional manner, i.e., by first tapping and screw
threading the member into an undercut bore drilled into the jaw. In
order to provide distraction osteogenesis, the jaw is surgically
cut as described in my prior patent application, and rather than
there being separate coronal and apical members, this new invention
comprises merely providing a unitary, combination distraction and
dental implant device which comprises a head and shaft, with the
shaft comprising a threaded, shank section and a smooth, distal
wall portion.
[0004] After the jaw is surgically cut as described in my prior
application and the combined dental implant/distractor of the
present invention is inserted in the jaw in the conventional
manner, distraction osteogenesis can be generated. This occurs
because the smooth, distal end of the device bears against, for
instance, a round section in the bone cut surface or a bottom,
round jaw surface (an alternate embodiment provides a base support
member, like a disc or washer). Thus, further turning of the
combined dental implant/distractor cannot cause it to move further
in a vertical direction. Rather, as the device is slowly rotated,
jaw tissue in the jaw segment (grown toward and adhered to the
distraction device) moves upwardly. In order to provide incremental
upward movement for the segmented jaw section, the distraction
device is rotated and the tissue which adhered to the distraction
device separates therefrom. Because of the threaded surface of the
upper shank section of the distraction device and the jaw tissue
which bears thereagainst, rotation of the device (blocked from
vertical movement) will cause the upper segment of the jaw to climb
or glide up the inclined plane of the threads or lift upwardly
because of the vertical/lifting pressure of the threads against the
contiguous and adjoining jaw section segment.
[0005] In order to enhance the healing process, in quality and
time, between the jaw tissue and the combined distraction/implant
device, BMP or other bone growth enhancing material can be
introduced. The growth enhancing substance can be applied directly
through interior channels in the distraction device either by using
a syringe placed downwardly in a throughhole to distribute the BMP
radially throughout channels in the device or it may be directly
applied to the interstices between the jaw tissue and the
distraction device itself. By providing such augmenting tissue
restorative material such as BMP, the process for causing
distraction osteogenesis and bone healing to occur will be
materially enhanced in time while reducing the trauma to the jaw
tissue which provides bearing surfaces for the distraction
device.
[0006] In another embodiment of this invention, a bottom plate or
apical member, preferably a small disc, can be inserted in a
drilled bore of the jaw prior to insertion of the combined
distraction and implant device so as to provide a more effective
bearing surface upon which the smooth distal end of the distraction
device will rotate and bear. Such an apical member or thin metal
plate could be made of a resorbable material such as PGA or PLA so
that placement of the unitary implant and distraction device can be
a one-time surgical activity in which the distraction device serves
not only to create distraction osteogenesis, but it also serves as
the support or implant securing mechanism for a later cap or crown
(prosthesis).
[0007] The inventor's own prior, referred-to patent application
(reproduced hereinafter) describes a system in which the implant is
placed in the lower jaw, upper jaw or is placed in a jaw section
(in the latter situation, an H cut is provided so to simultaneously
allow the upper and lower jaw segments in a single jaw section to
move opposite from each other). Distraction osteogenesis occurs
because of their adherence of tissue to the apical and coronal
members which move away from each other as the threaded distraction
member rotates. In the present invention, separate coronal and
apical members are no longer required because the distraction
member, itself, is provided with threads in the region in which
relative tissue movement is required for the sectioned jaw
segment--whether two segments move opposite to each other, an upper
segment moving upwardly towards the sinus or an upper segment in
the lower jaw moves to raise the gum line.
[0008] The dental implant distraction device of this invention is
physically identical, in one embodiment, to FIGS. 8A and 8B of my
prior patent application. The device comprises a biocompatible
material and is sized to be inserted into the jaw of a patient.
Thus, for the patent claims directed solely to the new embodiment
of the device itself, FIGS. 8A and 8B of my prior application
provide support for the claims and the filing date of the earlier
application shall apply to claims reading upon the device depicted
in FIGS. 8A and 8B.
[0009] This invention is directed to both an apparatus and the
method of creating distraction osteogenesis by providing a simple
single mechanical unit, a combination dental implant-distraction
device which is capable of creating distraction osteogenesis and
providing a support for a conventional implant, crown or
prosthesis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The numbering of the Figures in this patent application will
commence with FIG. 14 as FIGS. 1 through 13 are taken from my prior
patent application which is reproduced in its entirety hereinafter
and incorporated expressly herein. For purposes of ease of
reference:
[0011] FIG. 14 is a perspective view showing the integral,
combination dental implant-distraction device of this invention
which is also shown in FIGS. 8A and 8B of the prior
application;
[0012] FIG. 15 is a perspective view similar to FIG. 14 showing a
base, disc-like member or flat, apical member upon which the
smooth-walled and smooth end, distal portion of the dental
implant-distraction device bears during its rotation, thereby
providing distraction osteogenesis;
[0013] FIGS. 14 and 15 show the position of the dental implant
prior to the surgical cut in the bone creating the jaw surgical
section segment which moves relative to the remainder of the jaw
section; the surgical cuts were described in my prior patent
application.
[0014] FIG. 16 is an enlarged, partial, sectional view of the
threaded portion of the dental implant-distraction device and the
jaw tissue growing proximate thereto, which, in combination allows
the jaw segment to be moved upwardly as the distraction device
incrementally rotates and the threads of the device provide lifting
and inclined support for the jaw tissue thereby moving the jaw
tissue upwardly when the device is incrementally rotated;
[0015] FIG. 17 illustrates another embodiment of this invention in
which a covering cap for the dental implant-distractor device is
provided for improved hygienics. This embodiment shows a
combination dental implant-distraction device with a plurality of
internal pathways outwardly or radially emanating from a center
bore, extending through the dental implant-distraction device to
enhance distribution of BMP, introduced through the top bore, which
enhances tissue restoration and bone growth; and
[0016] FIG. 18 is an alternative embodiment of this invention in
which a center section of the dental implant distraction device is
smooth and the longitudinally extended segments are both threaded
thereby allowing for concurrent movement of both upper and lower
jaw segments with respect to each other by those jaw segments
bearing against the upper and lower threaded sections of the dental
implant-distraction device. This device could be used to promote,
for example, distraction osteogenesis in an upper jaw in two
directions, i.e., moving bone growth toward the sinus area and
moving the gum line to align with adjacent teeth and gum
structure.
[0017] FIG. 19 is a perspective view of an alternate embodiment of
a final connecting member, consistent with the invention fully
disclosed in my prior application; and
[0018] FIG. 20 is a perspective view of an alternate embodiment of
a combination dental implant and distraction member with a coronal
member, extra-osseously located.
Prior Patent application Ser. No. 09/886,078
[0019] The following section repeats and corresponds to the
specification (written description and drawings FIGS. 1-13,
including the Abstract of the Disclosure) of my prior patent
application Ser. No. 08/886,078 filed Jul. 2, 1997. To the extent
not exactly repeated herein, it is expressly incorporated herein by
reference. Minor changes may have been made for clarity and ease of
reading.
[0020] The present invention relates generally to dental implant
systems and methods for replacing missing teeth with dental
implants, more particularly, to dental implant systems and surgical
methods for replacing teeth with dental implants in areas of the
mouth that have suffered bone loss and most particularly to
combination distraction dental implant devices and methods for
replacing missing teeth in areas of the jaw bone having bone loss
using a three component combination distraction dental implant
device including two cylindrical like components and a connecting
third component or an expansion third component to grow new bone
and soft tissue by distraction osteogenesis;
[0021] Premature tooth loss can limit a patient's ability to chew
and speak clearly. Consequently, patients request tooth
replacement. In the past, dentists have been able to replace
missing teeth by means of removable prosthesis such as partial or
complete dentures. Other prior alternatives included the placement
of fixed bridge work cemented to adjacent teeth. These two prior
methods served only to fill the void of the edentulous space by
replacing the crown of the involved teeth but did not replace the
root.
[0022] Recently, the field of dental implantology has come into its
own, as the technology for replacement of the root and the crown
portion of the missing teeth has evolved. In dental implantology,
the root portion of the missing tooth is replaced first, by
surgically implanting a cylindrical root form dental implant into
the dentoalveolar bone (Stage I). There are a number of U.S.
Patents relating to dental implants, including the following: U.S.
Pat. Nos. 5,489,210; 5,470,230; 5,449,291; 5,334,024; 5,281,140;
5,269,685; 5,259,759; 5,154,612; 5,145,371; 5,125,841; 5,069,622;
5,064,425; 5,051,880; 4,960,381; 4,824,372; 4,798,205; 4,682,951;
4,657,510; 4,552,532 and 4,330,891 the disclosure of each is herein
incorporated by reference.
[0023] As the surgical site heals, the dental implant becomes
bonded and incorporated into the surrounding bone forming an
integral unit. The dental implant abutment for the creation of the
crown of the tooth later, once osseous healing had occurred (4-6
months), is placed at the time of Stage II uncovering.
[0024] In some instances, the above is accomplished by a one-stage
implant procedure. In the one-stage procedure, also known as the
nonsubmerged, either a one-piece fixture, in which the implant and
transmucosal portion are fused together, or both an implant body
and a healing cap are simultaneously placed. Instead of covering
the implant, the soft tissue is sutured around the protruding
transmucosal portion or healing cap and left to heal for the same 4
to 6 months. The advantages of one-stage implants is described in
detail in an article by Louis F. Clarizio, DDS, entitled "One-stage
Implants: An Overview of Their Usefulness and the Techniques for
Placement" in the Postgraduate Dentistry Series, Volume 3, Number
4, 1996 beginning at page 3, the disclosure of which is hereby
incorporated by reference.
[0025] Regardless of whether a one-stage or a two-stage implant is
used, long term success of dental implants depends upon two
factors: (1) the osseous incorporation or integration of the
implant with the native bone, and (2) the mechanical loading
properties of the prosthetic crown onto the dental implant.
Ideally, the longest (13-15 mm) and widest (2.5-5.5 mm) dental
implant should be placed in the bone to act as a proper foundation
for the tooth crown.
[0026] However, as a consequence of premature tooth loss, patients
have lost bone in the area of a proposed implant. This bone loss
has, in some cases, limited the surgical options, requiring the
dentist to place a smaller than optimal sized dental implant. If
the dental implant is too small to accommodate the mechanical load
from chewing, with time, it will loosen and fail. Thus, the longest
and widest implant available, as described above, (based on the
bone stock) should be placed. Additionally, due to bone loss or
insufficient bone in the implant area, the dental implant may be
placed in an anatomical location where the existing bone may not be
ideal for prosthetic reconstruction with a crown or bridge, forcing
the dentist to replace the missing tooth with a crown that is not
as aesthetic or functional as would be considered optimal.
[0027] One prior solution to this bone loss problem was to augment
the bony bed with the patient's own bone or cadaveric bone as a
transplant, or with synthetic bone substitutes. This procedure was
done at the time of dental implant placement if the bone loss is
not too great. Otherwise the bone augmentation must be done as a
first surgical procedure with the placement of the dental implant
occurring several months later, as a second surgical procedure,
once healing of the bone graft was completed.
[0028] Due to the anatomy of the craniofacial region (defined as
pertaining to the region of the head which contains the
craniofacial bones, including the maxilla, the upper jaw bone
includes the bones of the eyes, the hard palate and the nose, and
the mandible, the lower jaw bone, usually with reference to
specialized surgical or prosthetic reconstructions of this area of
the face), augmentation of the deficient bone is not as simple as
layering on the transplanted bone and allowing it to heal.
Occasionally, the maxillary sinus membrane (located in the upper
jaw) must be elevated or the inferior alveolar nerve (located in
the lower jaw) transposed to allow room for placement of the bone
graft. Regardless of the technique and materials used, the
potential morbidity to the patient can be significant.
[0029] Another prior technique of producing new bone was that of
distraction osteogenesis. Here, the body was "tricked" into making
new bone as it attempts to heal a fracture site. Using this
technique, the surgeon created an osteotomy or cut in the bone in
an area of bone deficiency. As long as a non-critical size gap
exists, the body attempts to heal itself by filling in the gap with
new bone. If the gap is widened daily, the body recognizes the
newly expanded gap and continues to fill the gap with new bone.
This results in creation of new bone in the expansion gap. As long
as the gap is expanded slowly over time (0.5-2.0 millimeters per
day), the body continues to heal the gap, generating new bone.
[0030] A critical size defect is one that will not heal on its own
i.e. a critical size defect is sufficiently large to allow only for
connective tissue healing without bone bridging between the two
ends of the defect. A non critical defect is one which will heal on
its own by filling in with bone. Each bone of the body has its own
"critical size" defect. If a critical size defect exists, then a
bone graft or a bone substitute must be placed to allow for osseous
regeneration.
[0031] Since the native bone is utilized as the template for
repair, the new bone generated has the same size and shape as the
original bone. This phenomenon of recreating the same size and
shape as the original bone is unique to bone generation using
distraction osteogenesis and is not accomplished with conventional
bone transplantation.
[0032] During distraction osteogenesis, in addition to creating new
bone, the overlying soft tissues are regenerated, a secondary gain
unique to distraction osteogenesis. This secondary beneficial
effect has significant clinical implications, for not only is the
underlying foundation properly established, but also the overlying
soft tissue is recreated providing for aesthetic and functional
rehabilitation of the defect.
[0033] Distraction osteogenesis defined as the generation of new
bone in response to the application of tension stresses placed
across an osteotomy site (bone cut site), has been successfully
applied to the bones of the maxillofacial region and specifically
to the dentoalveolar unit using distraction devices that are
external to at least the gums inside the mouth and, in some cases,
completely external the mouth. In these prior instances of applying
distraction osteogenesis prior to placing a dental implant, an
osteotomy (corticotomy) is made in the bone adjacent to the area
requiring bone augmentation and one of the prior bone expansion
devices was applied. After allowing for a period of initial
healing, the prior device was activated by the patient at home,
advancing the distraction gap about 0.5 to about 2.0 millimeters a
day. For a more complete description of distraction osteogenesis,
see the article "Osteodistraction" by the inventor of the present
application in Selected Readings in Oral and Maxillofacial Surgery,
volume 4, Number 7, published by the University of Texas,
Southwestern Medical Center at Dallas, in 1996, the disclosure of
which is herein incorporated by reference.
[0034] After a sufficient amount of new bone matrix was generated,
the distraction device was left in place to allow for ossification
of the newly generated bone. The prior distraction devices were
then removed during a second surgical procedure and dental
implant(s) are placed. Once again the patient was required to
undergo two surgical procedures: (1) bone generation via
distraction osteogenesis and (2) placement of the dental
implant.
[0035] A minimum of about ten (10) to about fifteen (15)
millimeters of bone was required to utilize the existing
distraction devices. If there was not enough bone stock to place
the existing devices, a bone graft was required prior to the
distraction device being placed. In this case, the patient was
required to undergo three separate surgical procedures.
[0036] The current external and submerged distraction devices are
also limited in the amount of bone expansion each device can
deliver because they have fixed internal mechanisms which provide
for bone expansion from 0.0 mm to the full length specified for a
particular device. Presently, for an external distraction device
the full length is about 40 mm while for an intraoral distraction
device, the full length is about 18 to about 20 mm. Should more
bone expansion be required, then a new device was required to be
placed during yet another surgical procedure (fourth).
[0037] These prior distraction devices took essentially two
approaches: (1) the device was situated externally, outside the
skin, with pins holding the device in place to the bone, or (2) the
device was situated intraorally, inside the mouth, along the gum
line, with pins or screws holding the device in place. Devices
which are located externally function well but can pose aesthetic
concerns while the patient is utilizing the device and also facial
scars are created as the pins holding the device in place are moved
as the device is activated and the bone is expanded. Intraoral
devices do not have as many aesthetic concerns, but are bulky,
displacing the lips and cheeks, which can give the patient the
appearance of a local infection.
[0038] As can be seen above, in the worst case, some patients were
required to undergo as many as four (4) separate surgical
procedures over a lengthy time period in order to achieve an
optimal dental implant. It should be obvious that it is desirable
to limit the number of surgical procedure a patient must
undergo.
[0039] Thus, there is a need for new devices and methods for
placing optimally sized dental implants in areas having
insufficient bone. Such new devices and methods should reduce the
number of surgical procedures a patient must undergo to achieve an
optimal implant; should significantly reduce the number of
individual distraction devices required for obtaining the
appropriate amount of bone in the implant site; should reduce the
number of surgical procedures required for placing an optimal
implant in the implant site; should incorporate as many features of
the prior devices as possible into a combination distraction dental
implant device; should reduce patients aesthetic concerns; should
reduce, if not totally eliminate, displaced lips and cheeks and
should reduce, if not totally eliminate, the need for bone
grafts.
SUMMARY OF THE INVENTION
[0040] It is accordingly one object of the present application to
provide a new combination dental implant and distraction device and
method of using which limits the number of surgical procedures a
patient must undergo to have an optimum dental implant placed in an
area having initially insufficient bone stock.
[0041] Another object of the present invention is to provide a
combination distraction dental implant device and method of using
the device that combines the technology of dental implantology and
that of distraction osteogenesis such that a combination
distraction dental implant can be utilized as both the bone
distraction device and, after the distraction, left in place as the
dental implant.
[0042] A still further object of the invention is to provide a
combination distraction dental implant device that is utilized as
the root form for a prosthesis such as, for example, a crown, a
bridge or dentures.
[0043] Another object of the invention is to provide a combination
distraction dental implant that eliminates the need for the
complete removal of the distraction device prior to placement of a
separate dental implant during another surgical procedure.
[0044] A further object of the present invention is to provide a
combination distraction dental implant that eliminates the need for
bone grafts in areas of limited bone stock in order to place
optimal dental implants.
[0045] Another object of the invention is to provide a combination
distraction dental implant that lifts the sinus during the
distraction process.
[0046] The above and other objects of the present invention are
realized by combining the technology of dental implantology and
that of distraction osteogenesis to produce a combination
distraction dental implant which serves as both the implant and the
distraction device. In preferred embodiments and methods of the
present invention, a combination distraction dental implant is
utilized as both the distraction or bone expansion device and the
dental implant device and is left in place after distraction in the
place of the prior conventional dental implant.
[0047] One representative embodiment of a specific [0048]
combination distraction dental implant comprises: a hollow coronal
component; a partially hollow apical component initially having at
least one surface contiguous with at least one surface of the
hollow coronal component; and at least one expansion component for:
(a) operatively connecting the hollow coronal component and the
partially hollow apical component, and [0049] (b) controllably
expanding the distance between the contiguous surfaces of the
hollow coronal component and the partially hollow apical component
to form a gap.
[0050] Another representative embodiment of a specific combination
distraction dental implant for placing an optimum dental implant in
an area having initially insufficient bone stock comprises: a
hollow coronal component; a partially hollow apical component
operatively positioned proximal the hollow coronal component; and a
removable connecting component operatively connecting the hollow
coronal component and the partially hollow apical component.
[0051] One representative method of the present invention includes
the steps of: providing a three component distraction device
including a hollow coronal component, a partially hollow apical
component and a linking component or a first expansion component;
placing the combination distraction device in a predetermined site
where bone regeneration is required; allowing the combination
distraction device to become integrated into the bone; ensuring
that osseous incorporation of the combination distraction device
into the bone has been accomplished; performing a corticotomy in
the buccal bone at the level of the contiguous surfaces of two of
the three components of the combination distraction device to form
a distraction gap; educating the patient as to the care and
activation of the three component combination distraction device;
after allowing for a period of initial healing, maneuvering the
connecting component thereby separating the coronal component and
the apical component to widen the distraction gap in the bone.
[0052] Another representative embodiment of a more general purpose
distraction device of the present invention includes: a first
component selectively operatively removably connectable to a first
predetermined portion of a bone; a second component selectively
operatively removably connectable to a second predetermined portion
of the bone, the second component being operatively positioned
proximal the first component; and a connecting component for: (a)
operatively connecting the first and the second components, and (b)
controllably expanding the distance between the first and the
second components.
[0053] Other objects and advantages of the present application will
become apparent from the following description, the accompanying
drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] FIG. 1 is an exploded view of a representative prior
conventional dental implant with the implant shown placed in the
upper jaw bone;
[0055] FIG. 2 is an exploded view a representative combination
distraction dental implant of the present invention with parts
shown in phantom;
[0056] FIG. 3 is an exploded cross-sectional view of the
representative combination distraction dental implant of FIG.
2;
[0057] FIG. 4 is a perspective view of the representative
combination distraction dental implant of the present invention
shown after initial placement in an area of the jaw requiring
additional bone;
[0058] FIG. 5 is a perspective view of the representative
combination distraction dental implant of FIG. 4 shown after
initial placement in an area of the jaw requiring additional bone
and after some bone has be generated;
[0059] FIG. 6 is a perspective view of the representative
combination distraction dental implant of FIG. 4 shown after
initial placement in an area of the jaw requiring additional bone
and after additional bone has be generated;
[0060] FIG. 7 is a perspective view of the representative
combination distraction dental implant of FIG. 5 shown after
sufficient bone has be generated to support an optimum crown;
[0061] FIG. 8A is a perspective view of one representative
expansion component of a plurality of different size expansion
components usable with the combination distraction dental implant
of the present invention;
[0062] FIG. 8B is a perspective view of another representative
expansion component of a plurality of different size expansion
components usable with the combination distraction dental implant
of the present invention;
[0063] FIG. 8C is a perspective view of a representative abutment
usable with the combination distraction dental implant of the
present invention;
[0064] FIG. 9 is a schematic view of a maxillary sinus in an area
of the jaw having diminished bone height requiring additional bone
prior to the placement of an implant;
[0065] FIG. 10 is a schematic view of the representative
combination distraction dental implant of the present invention
shown after initial placement in an area of the jaw requiring
additional bone;
[0066] FIG. 11 is a schematic view of the representative
combination distraction dental implant of FIG. 10 shown after
initial placement in an area of the jaw requiring additional bone
and after some bone has been generated lifting the maxillary
sinus;
[0067] FIG. 12 is a schematic view of the representative
combination distraction dental implant of FIG. 11 shown after
additional bone has been generated further lifting the maxillary
sinus; and
[0068] FIG. 13 is a schematic view of a representative combination
distraction dental implant of FIG. 11 shown after sufficient bone
has been generated to support an optimum crown and even further
lifting the maxillary sinus.
DETAILED DESCRIPTION OF THE INVENTION
[0069] The science and technology of dental implants have been
described above. As such, dental implants have evolved from a
simple cylindrical form to now having external threads, self
tapping grooves, vertical grooves, vents, apical holes and treads,
and surface coatings/treatments (titanium plasma spray, acid-etch,
hydroxylapatite, microspheres, sintered pores, bone promoting
substances, selective surface combinations), etc., all of which act
to serve as mechanisms to facilitate placement and promote bone
healing, thus increasing retention of the implant within the bone.
As is known, dental implants can be made of various grades of
titanium (Grade I-IV) to increase the strength of the implant
itself. Implants may also be stepped or tapered apically, allowing
for placement into narrow anatomical spaces. Implants may have a
smooth collar to provide for cervical healing. Implants may have
external or internal hexagonal, octagonal, spline and other designs
to allow for increased retention and anti-rotation,
friction-fit/interference-fit of the prosthesis such as, for
example, a crown, a bridge or dentures onto the implant.
[0070] Regardless of the specific manufactures design, a dental
implant serves to replace the missing root shape of the tooth,
utilizing the best mechanical form available for that manufacture's
design. Ultimately the design of any dental implant is dictated by
its clinical success. Consequently, variations in the basic design
of root form dental implants is limited.
[0071] FIG. 1 illustrates a representative conventional dental
implant. This conventional dental implant 20 comprises a cylinder
like member 22 having internal threads (not shown) for receiving a
post 26 which supports a dental prosthesis such as, for example, a
crown 28, a bridge or dentures. The cylinder like member comprises
a neck portion 30 for connection with the post 26, a body portion
32 and an apex portion 34.
[0072] In one exemplary embodiment of the present invention, the
three component combination distraction dental implant device
includes a two component externally smooth or threaded, stepped or
tapered portion with round ends made of, such as, for example,
implant grades of titanium or other material that performs
effectively in implant usage. The external surface of the,
presently preferably cylinder like, combination distraction dental
implant may be smooth, roughened or coated with bone augmentation
materials (hydroxyapatite, bone morphogenic proteins, titanium
plasma spray, microspheres, sintered pores, selective surface
combinations, etc.). The cylinder like portion of the combination
distraction dental implant is separated horizontally, dividing the
cylinder like portion of the combination distraction dental implant
into two components, an apical component and a coronal component.
The apical component of the implant may be modified to contain
through and through ports, such as, for example, in a x-fashion or
a y-fashion port configuration or two (2) holes through and through
to allow for osseous incorporation. The apical and the coronal
components, presently preferably, contain internal threads, or
equivalent structure, into which a connecting component or an
expansion component is operatively placed. The internal structure
of the apical and the coronal components are adapted to operatively
cooperate with the expansion component such that (1) at a minimum,
the two components are operatively connected together and (2) the
distance between the apical component and the coronal component is
selectively varied.
[0073] When initially used, the connecting component is advanced
into the two separable apical and coronal components by rotating,
for example, the connecting component in a clockwise direction. As
the connecting component is advanced into the coronal component and
then into the apical component of the combination distraction
dental implant, the body of the connecting component cooperates
with the internal structure of the coronal component and one end of
the connecting component operatively engages the internal structure
of the apical component and effectively connects the two components
together.
[0074] When the two components having the initial connecting
component operatively positioned therein have become sufficiently
integrated with the bone, the initial connecting component is
removed and replaced with a first expansion component for causing
separation between the apical and coronal components thereby
expanding a surgically created distraction gap in the bone. Since,
when properly placed in a patient's bone, the apical and coronal
components become integrated, fused intra-osseously to the bone,
separating these two components expands the distraction gap
previously made in the bone proximal to the separation point
between the two components. The separation of the components is
dependent upon the cuts in the bone. If the bone is cut
perpendicular to the horizontal cut in both directions, then the
components will move apart, as in a sinus lift. If the bone is cut
perpendicular to the horizontal cut in only one direction, then
only the component most proximal the perpendicular cuts will
move.
[0075] Both the initial connecting component and the expansion
component are designed to be removable from a position connecting
the apical and the coronal components, such as, for example, by
reversing the direction of rotation. Once removed, the expansion
component may be replaced with a longer expansion component,
allowing for incremental distraction osteogenesis, or by an
abutment for receiving a crown, once sufficient bone has been
regenerated to support an optimal implant.
[0076] In any event, any one of the plurality of possible sized
expansion components are operative to both connect and controllably
separate the two separable components of the combination
distraction dental implant and provides for the controllable
separation of the separable apical and the coronal components
during the distraction process. Upon completion of the distraction,
the expansion component is replaced by the abutment which becomes
incorporated into the bone during healing.
[0077] In one representative surgical approach, the combination
distraction dental implant device is placed by making an incision
along the crest of dental ridge exposing the underlying bone. Using
sequentially sized drills, an osteotomy is created in the planned
implant placement site. The osteotomy is sized such that the
cylindrical distraction implant will fit with a friction fit. A tap
drill may also be utilized to tap the bone site to receive the
threaded type of distraction implant. The appropriately sized three
component combination distraction dental implant is then placed and
the incision is closed, with either the top of the initial
connecting component extending through the soft tissue or covered
by the soft tissue, the cap being flush with the surface of the
bone. The combination distraction dental implant is then allowed to
heal and become integrated into the bone.
[0078] If a two-stage implant procedure was determined appropriate,
during Phase II, uncovering, the buccal portion of the bone is
exposed. Next in both the one-stage and the two-stage procedures,
osseous integration of the combination distraction dental implant
is verified visually, tactilely and radiographically, as
appropriate. In one presently preferred method, using radiographs,
a corticotomy is created in the buccal bone at the level of the
combination distraction dental implant separation site i.e., the
position where the apical component and the coronal component are
contiguous. The buccal cortex is scored/cut at the same horizontal
level. Two vertical bicortical osteotomies are then created at the
limit of the edentulous space, the area to be expanded. The
incision is closed with the initial distraction connecting or
expansion component extending intra-orally. After a latency period
and after replacing the initial connecting component, if used, with
an expansion component, the distraction expansion component is
activated separating the distraction gap, i.e. the gap between the
apical component and the coronal component. After adequate bone
height is achieved, the last of the plurality of possible sized
expansion components is removed and replaced with an abutment which
acts as the basis for a prosthesis such as, for example, a crown, a
bridge or dentures.
[0079] In one specific method of the present invention, the bone
site for the combination distraction dental implant is created and
the three component combination distraction dental implant placed.
After the combination distraction dental implant has integrated
into the bone, the distraction implant is surgically approached. A
bone cut is made at the level of the planned distraction gap. The
new bone cut is allowed a period of initial healing, and the
distraction process is then initiated. This distraction activation
can be coupled with (Stage 11) uncovering of three component dental
implant. As the gap between the apical and the coronal components
of the combination distraction dental implant is advanced, the
distraction gap is expanded providing for new bone formation. Once
the desired amount of new bone growth has been achieved, an
abutment replaces the last expansion component of the three
component combination distraction dental implant and the apical and
the coronal components with the abutment connecting them together
is allowed to heal in position.
[0080] The following is a specific representative example of the
application of the combination distraction dental implant methods
and device of the present invention to the science and technology
of dental implants. It is believed that most, if not all, current
dental implants could be modified, in accordance with the present
invention, to allow for the application of the additional
distraction as long as the components of the combination
distraction dental implant are sufficiently strong to withstand the
loads and to effectively distribute the loads from the combination
distraction dental implant to the bone.
[0081] As shown in FIGS. 2 and 3, one specific, presently
preferred, embodiment of the combination distraction dental implant
of the present invention is generally designated by the numeral 40
and comprises three components including a two component 42, 44,
presently preferably, externally threaded cylinder like portion 46
and at least one initial connecting component 48 or one of a
plurality of expansion components 48a, 48b for cooperating with the
two components 42, 44 an apical component 44 and a coronal
component 42 for operatively connecting and for controllably
separating the two components.
[0082] The two components 42, 44 presently preferably, are about
four (4.0) mm in diameter and combined are about eight (8.0) mm in
length, and are made of, presently preferably, commercially pure
Grade IV titanium (other metals, metal alloys or metal substances
could be used as long as they meet or exceed the parameters for
material used in dental implantology). The outer surface of both
components of the cylinder like portion of the present invention
can be conventionally covered/roughened with a surface coating
extending about one (1.0) mm to about two (2.0) mm from the
superior aspect of the combination distraction dental implant along
the entire length of both components 42, 44. The two components 42,
44 of the combination distraction dental implant 40 are, presently
preferably, cylinder like, and having, presently preferably,
conventionally externally threaded, with the, presently preferably,
clockwise treads starting about two (2.0) mm from the superior
aspect of the combination distraction dental implant along the
entire length. The apical component 44 of the combination
distraction dental implant includes conventional means 50 for
enhancing integration with the bone and for reducing rotation of
the implant once integrated with the bone. One example, and the
presently preferred means, is three oblong apical vents 52, 54, 56
about one (1.0) mm in diameter located about one half (0.5) mm
superior to the end of the apical component 44 of the two
components of the combination distraction dental implant 40.
[0083] The two components 42, 44 have a combined hollow portion 60
extending from the superior surface for about six (6.0) mm of the
total about eight (8.0) mm length of the two components 42, 44
(completely throughout the about four (4.0) mm length of the
coronal portion 42 and about two (2.0) mm into the upper portion of
the apical portion 44). The hollow portion 60 is stepped with the
apical portion, about a two (2.0) mm portion, having about a two
(2.0) mm diameter and the coronal portion, about a four (4.0) mm
portion having about a three (3.0) mm diameter. The about two (2.0)
mm superior, coronal, portion 62 of the hollow inner portion 60 has
a hexagonal configuration, with the coronal portion about one half
(0.5) mm flared outward producing a knife edge junction. The
remaining inner portion of the about two (2.0) mm long portion, of
the about three (3.0) mm wide portion is round, with, presently
preferably, clockwise threads. The hollow about two (2) mm diameter
portion 61 of the apical component 44 is round, with, presently
preferably, clockwise threads.
[0084] Prior to, during and after initial placement, the horizontal
interface between the two about, four (4.0) mm long components 42,
44 has no noticeable gap (See FIG. 4). This interface may be smooth
or have interlacing or interlocking complimentary locking members
on the facing surfaces 58, 59 of the components 42, 44. Such
members would prevent rotation and torsion at the interface during
the healing process and before the components become integrated
with the bone. As mentioned above, the combination distraction
dental implant device 40 also includes one of the plurality of
incrementally sized expansion components 48a, 48b, as shown in
FIGS. 8A and 8B, for operatively connecting the two components 42,
44. As described above, the expansion component provides for
separation between the above described two components 42, 44 to
form a distraction gap 70, once the two components 42, 44 connected
by the initial connecting component 48 are properly integrated with
the bone 80. (See FIGS. 4-6)
[0085] As illustrated in FIGS. 8A, and 8B, the expansion component
preferably comprises one of a plurality of separate interchangeable
members 48a, 48b of varying lengths each having means for
separating the two components 42, 44. The end portion 112 of the
interchangeable expansion components 48a, 48b must be, of
necessity, rotatable in the hollow portion 61 of the component 44,
as will be discussed in detail below. The plurality of expansion
components 48a, and 48b in one exemplary example, comprise separate
members of about five (5.0) mm 48a, about ten (10.0) mm 48b, about
thirteen (13.0) mm (not shown), about fifteen (15.0) mm (not
shown), and about 18.0 mm (not shown) in length, presently
preferably, made of commercially pure titanium or equivalent. Each
expansion component is, presently preferably, T shaped with a
threaded vertical portion 82 and a smooth superior cap portion 84.
The vertical portion 82 is about two (2.0) mm in diameter with
threads operatively corresponding to the internal threads of the
two components 42, 44 of the distraction implant device 40 and for
cooperation therewith. The height of the threaded portion has
varying lengths, such as, for example, about four and one half
(4.5) mm for the about five (5.0) mm expansion component, about
eight (8.0) mm for the about ten (10.0) mm expansion component,
about eleven (11.0) mm for the about thirteen (13.0) mm expansion
component, about thirteen (13.0) mm for the about fifteen (15.0) mm
expansion component, and about sixteen (16.0) mm for the about
eighteen (18.0) mm expansion component.
[0086] The initial connecting component 48, and the final abutment
component 100 each have a threaded end portion 110 for interaction
with the hollow portion 61 of the apical component 44. The end
portion 112 of the interchangeable expansion components 48a, 48b
must be, of necessity, rotatable in the hollow portion 61 of the
component 44 because, as the expansion component is rotated the
expansion component 48a must not be fixedly connected to the apical
component 44 in such a way as to prevent the end 112 from freely
rotating in the apical component 44 as both the apical component 44
and the coronal component 42 remain rotationally fixed in the bone
as the gap between the two components 42, 44 is increased axially
by the interaction of the external threads of the expansion
component 48a, 48b with the internal threads of the coronal
component 42. Other conventional means for maintaining the
rotatability of the end portion 112 in the hollow portion 61 would
be acceptable.
[0087] The key concept is that the apical component 44 and the
coronal component 42 remain stationary in the bone and rotational
movement of the expansion component 48a, 48b, provided by, such as
for example, the interaction of the threads of the expansion
component with the internal threads of the coronal component 42,
provide for the separation of the coronal component 44 and the
apical component 42. Specifically, during the rotation of the
expansion component after the end 112 of the expansion component
48a is contiguous with the bottom surface 63 of the apical
component 44, the end component 112 freely rotates within the
hollow portion 61.
[0088] The superior aspect, cap portion 84, of the initial
connecting component 48 (see FIG. 2) is, presently preferably,
about four (4.0) mm in diameter and either about one (1.0) mm high
when unexposed or about three (3.0) mm high when exposed for the
five (5.0) mm long component or about two (2.0) mm high for the
remaining above described expansion components.
[0089] When seated, the about one (1.0) mm cap of the initial
connecting component 48 sits flush with the edge of the combination
distraction dental implant, while the about three (3.0) mm cap
extends beyond the edge of the combination distraction dental
implant 40 through the mucosa 90, intraorally (See FIGS. 4-7). The
about two (2.0) mm cap has concentric lines spaced about 1.0 mm
apart along the entire length of the cap. The superior aspect 92 of
the cap is tapered inward along the about one half (0.5) mm of the
one (1) mm height to correspond to the internal taper of the
superior aspect/knife edge of the combination distraction dental
implant 40. The top, superior surface 94 of the expansion component
cap has about a one (1.0) mm diameter, hexagonal shaped aperture
96, about two (2.0) mm in depth. This aperture 96 provides the
mechanical access to remove the initial connecting components 48
and to both place and remove a selected one of a plurality of the
expansion components 48a, 48b from its connecting position between
the two components 42, 44 and to activate the distraction process
via a corresponding L or T shaped hexagonal key (not shown), of
about one (1.0) mm diameter, presenting preferably, made from
stainless steel, by causing separation of the two components 42, 44
of the combination distraction dental implant 40, as will be
described more fully below.
[0090] As shown in FIG. 8C, the abutment 100, for final connecting
of the two components 42, 44, for being integrated with the bone
and for attaching the prosthesis such as, for example, a crown 28,
a bridge or dentures (FIG. 1) will now be described. The abutment
100 has essentially the same dimensions of the expansion components
48a, 48b but the overall length and the cap portion 84 as well as
the end 110 most remote from the cap are necessarily altered. The
cap portion 102 of, such as, for example, the crown attaching
expansion component or abutment 100 is, in its presently preferred
configurations, about six (6.0) mm high and about four (4.0) mm
wide at its base, extending upward with no more than an about
twenty-three (23) degree taper. From the widest aspect, the cap
102, presently preferably, tapers inward about two (2.0) mm to form
a taper that provides for a friction fit with the internal knife
edge taper of the superior portion of the combination distraction
dental implant. The cap taper meets the threaded portion at about a
right angle. The abutment cap 102 has the same about one (1.0) mm
diameter hexagonal access aperture in its superior surface. This
final abutment component is the component utilized as the base for
the prosthesis such as, for example, a crown 28, a bridge or
dentures after sufficient bone growth through distraction
osteogenesis has been generated by the controlled separation of the
two components 42, 44 by the expansion component. The cap portion
102 may also be configured as a ball, bar, magnet or any abutment,
as is known in the art. The end 110 of the abutment 100 must be
operative to interlock with the component 44 such that during bone
integration, the two components 42, 44 remain fixedly
connected.
[0091] As illustrated in FIGS. 4-7, in one presently
preferred-method for the distraction of bone using the combination
distraction dental implant 40 described above, the combination
distraction dental implant 40 device is placed by making a series
of osteotomies within the dentoalveolar bone in the predetermined
site or area where additional bone is required. Prior to any
surgical technique, proper treatment planning must be performed,
including a physical examination, X-ray studies and consultation
with the dentist fabricating the prosthetic crown.
[0092] Once the patient has been conventionally prepared for
surgery, a local anesthetic is given and infiltrated into the
surgical site. After allowing adequate time for anesthesia and
vasoconstriction, incisions are made along the crest of dental
ridge, in the predetermined site. The underlying bone is
conventionally exposed by raising a full thickness mucoperiosteal
flap with an elevator. The exposed bone is conventionally evaluated
by palpitation for bone density and quality.
[0093] Using sequentially sized drills, (an acceptable set is
available from Dentsply.RTM. Implant, 15821 Ventura Blvd., Ste.
420, Encino, Calif. 91436) as is presently preferred, an osteotomy
is created in the planned implant placement site, it being
understood that other conventional procedures could be used to
create the osteotomy. First, presently preferably, about a two
(2.0) mm diameter pilot drill is used to initiate the osteotomy
site, such as, for example, to a depth of about eight (8.0) mm. All
of the bone drilling procedures include copious amounts of
irrigation, (internally and/or externally). Conventional
paralleling pins of about two (2.0) mm diameter are placed into the
pilot holes to ensure the proper orientation and location of the
combination distraction dental implant in the bone. The osteotomy
site is enlarged by utilizing progressively wider drills. The
proper orientation and depth of the osteotomy site is verified by
re-placing the paralleling pins. Optionally, the parallelism of the
osteotomy site can be verified by X-rays. The final sized osteotomy
site is completed by either utilizing the final, smooth, twist
drill or by tapping in the threads corresponding to the combination
distraction dental implant.
[0094] At this point, the three component combination distraction
dental implant 40 of the present invention is placed (see FIG. 4)
into the bone 80 manually or by use of a conventional implant drill
set at slow speeds, as is known by those skilled in the art. The
wound is irrigated and the incision is conventionally closed with
the cap 84 being, presently preferably, covered by the gum tissue.
In a one-stage implant procedure, the cap is exposed, as described
above.
[0095] The three component distraction dental implant 40, presently
preferably, with the initial connecting expansion component 48 is
then allowed to heal and become integrated into the bone (a process
that takes approximately four months). It should be understood that
it may be possible to substitute a first expansion component 48a in
place of the initial connecting component 48, as long as the
portion extending above the gum does not extent above the top of
any adjacent tooth and as long as other medical concerns are met as
appropriate.
[0096] After physical examination and X-ray evaluation are utilized
to ensure osseous incorporation of the combination distraction
dental implant, the top 84 or superior portion of the combination
distraction dental implant is exposed during the Phase 11,
uncovering surgical procedure in a two-stage procedure where the
implant is completely covered (not shown). In the case of a
one-stage implant, the cap is not covered, as shown in FIGS.
4-7.
[0097] During either the one-stage or the two-stage procedure,
local anesthetic is administered, after the patient has been
prepared for surgery. Incisions are made in the gum over the site
of the combination distraction dental implant (two-stage
procedure). A full thickness mucoperiosteal flap is raised along
the buccal portion utilizing a periosteal elevator. Osseous
integration of the two component combination distraction dental
implant 40 into the bone is verified visually and tactilely. Using
a burr and copious amounts of irrigation, a corticotomy is placed
in the buccal bone horizontally, adjacent the two components
separation point (about 4.0 mm from the superior dental aspect of
the combination distraction dental implant). The horizontal
corticotomy, presently preferably, extends laterally about one
(1.0) mm to about seven (7.0) mm beyond the margin of the two
component combination distraction dental implant or as appropriate,
depending upon the judgment of the surgeon.
[0098] Two vertical bicortical osteotomies are created extending
from the horizontal cut to the crest of the dental ridge. This cut
can also be preformed in the opposite direction, apically to allow
for the sinus lift procedure, as described later. The vertical
osteotomies are completed with a thin osteotome. Care is taken not
to perforate the lingual periosteum or mucosa. The horizontal cut
remains as a corticotomy. If the combination distraction dental
implant has been placed in an area of limited bone stock, about one
(1) to about two (2) millimeters, between the implant and the
adjacent teeth/nerve, then only corticotomies are performed
including on the lingual.
[0099] At this point, the patient has been prepared for the process
of growing new bone stock by distraction osteogenesis prior to the
prosthesis such as, for example, a crown, a bridge or dentures
being connected to the implant. First, if used, the initial
connecting component 48 is removed and replaced by a first
adjustable expansion component 48a. The incision is then closed,
with the cap of the adjustable expansion component 48a extending
about five (5.0) mm through the mucosa, intraorally.
[0100] The patient is educated as to the care and activation of the
three component combination distraction dental implant. After
allowing for a period of initial healing, a latency period (of
about 5-7 days), the adjustable expansion component 48a is
maneuvered, (turned) thereby separating the two components 42, 44
of the combination distraction dental implant 40 of the present
invention (about 1.0 mm per day) in divided doses, as is known in
the art, and thus creating and widening the distraction gap 70 in
the bone.
[0101] The patient is educated to make the adjustment necessary to
increase or widen the gap 70 each day. Thereafter, the patient is
seen for follow-up and evaluation as appropriate. Since the
plurality of expansion components 48a, 48b are incrementally sized
by about five (5.0) mm, the maximal distraction gap advancement
achieved by any one expansion component is about five (5.0) mm. If
greater bone growth is required, the first expansion component 48a
can be removed and replaced by the next longer sized expansion
component 48b and the distraction process reinitiated, to achieve
further bone regeneration, as above (See FIGS. 4-7).
[0102] If an initial expansion component 48a was used instead of
the initial connecting component 48, the actuation process, after
healing, is followed, as described above.
[0103] Since the typical height of a natural tooth crown 111 above
the gum 90 is about eight (8.0) mm, in order to properly function,
the distal or cap end of the expansion component 48a should not
extend above the level of the lowest adjacent tooth crown 111.
[0104] After sufficient bone height (about 5 mm to about 15 mm) is
achieved, the distraction process is halted and the last adjustable
expansion component is removed and replaced with the abutment 100.
However, since the new bone is still relatively weak and
incompletely ossified, a period of about four to about six weeks is
required before the fabrication and installation of the final
prosthesis such as, for example, a crown 28, a bridge or dentures.
Additionally during this period, the abutment 100 now connecting
the two components 42, 44 of the combination distraction dental
implant becomes incorporated with the bone thereby increasing the
rigidity of the installed combination distraction dental implant
device 40 of the present invention.
[0105] FIGS. 4-7 illustrate the distraction process according to
the present application. FIG. 4 shows the combination distraction
dental implant 40 of the present invention newly installed in an
area having insufficient bone to support an optimal dental implant.
FIG. 5 shows an intermediate bone growth situation where some bone
has been regenerated but not enough to support an optimal dental
implant. Note the increased separation between the coronal 42 and
apical 44 components and the increased distraction gap 70. FIG. 6
shows another intermediate bone regeneration position with FIG. 7
showing the final result with the abutment 100 being positioned
connecting the two components 42, 44.
[0106] As clearly illustrated in FIGS. 4-6, as the bone is
regenerated and the expansion component 48a becomes nearly flush
with the gum, the expansion component connecting the coronal 42 and
apical 44 components is removed and replaced with the next longer
of the plurality of expansion components 48b such that, presently
preferably, the end extending intraorally does not extend above the
adjacent teeth, a height of about five (5) millimeters.
[0107] The foregoing description illustrated one specific
application of the technique and technology of distraction
osteogenesis to the field of dental implants using an exemplary
device and method. Since conventional dental implants have similar
basic forms, it should be apparent to those skilled in the art that
the potential combinations of the three component combination
distraction dental implant devices is unlimited. By modifying minor
details of the basic design, such as, for example, splitting the
dental implant horizontally 60/40% rather than the 50/50% as
described, altering the length or taper of the expansion component,
changing the pitch of the screws, etc., are just a few of the
unlimited possible variations.
[0108] Nevertheless, in all possible variations, the basic concept
remains as described, i.e., utilizing two separate components 42,
44 connected by one of a plurality of adjustable expansion
components to achieve sufficient bone generation in an area of
deficient bone in order to place an optimum dental-implant.
Advantages of combination distraction dental implant of the present
invention include providing new bone and soft tissue formation,
thereby, reducing the number and morbidity of surgical procedures a
patient is subjected to during the distraction as compared to
the-prior surgical procedures. Additionally, the three component
combination dental implant described above provides for increased
versatility by using a plurality of interchangeable, incrementally
seized expansion components 48a, 48b to continuously adjust the
distraction gap 70 during the bone regeneration process without
additional surgical procedures. Consequently if more bone is
required than initially anticipated, then the expansion component,
and only this single component, is removed and replaced with a
longer one to provide the additional bone generation until
sufficient bone is generated then the last expansion component is
replaced by the abutment 100.
[0109] As shown in FIGS. 9-12, utilization of the device of the
present invention for cases where the bone is deficient and the
sinus must be elevated. As shown in FIG. 9, the device 40 of the
present invention is placed in the bone 80 with the apical
component 44 proximate the boundary between the bone 80 and the
maxillary sinus 200.
[0110] FIGS. 10-12 illustrate the regeneration of the bone as the
apical component 44 effectively lifts the maxillary sinus 200 in
gradual phases through distraction osteogenesis by regenerating
bone between the apical 44 and the coronal 42 components.
[0111] In this method, one possible approach is to have both the
coronal component 42 and the apical component 44 generate bone by
having the apical component 44 push toward the sinus 200 and the
coronal component 42 move toward the crown of the adjacent teeth
and increase the bone between the sinus and the gum. Therefore,
when the force is applied to separate the two components,
distraction takes place by moving both components, depending upon
the bone cuts (osteotomies), as previously described.
[0112] As can be seen from the drawings, it is believed possible to
elevate the maxillary sinus while generating sufficient bone to
provide the equivalent of the conventional bone graft system of the
prior art. One representative prior method and apparatus for
lifting a descendent portion of the maxillary sinus is disclosed in
U.S. Pat. No. 4,682,951, the disclosure of which is herein
incorporated by reference.
[0113] Thus, it can be seen that the new combination intraossoeus
dentoalveolar distraction osteogenesis implant and method of using
includes a new three component device which reduces the number of
surgical procedures required to place a dental implant in an area
initially having insufficient bone stock to support the optimal
implant and is more aesthetically pleasing during the actual
distraction process as compared to prior devices and methods.
[0114] It should be clear to those skilled in the art that the
above concept of a three component distraction device with
interchangeable expansion components is not limited to use as a
dental implant and could be used as a general distraction device in
the maxillofacial region, for example, by externally attaching the
coronal component and the apical component to appropriate areas of
a bone by connecting means, such as, for example, pins, screws,
rods, titanium discs, etc., as known by those skilled in the art.
When attached external to the bone and soft tissue (extra mucosal),
the same distraction principles would apply including the variable
size interchangeable connecting components.
[0115] In fact, a plurality of interchangeable, incremental
devices, each device comprising a first component operatively,
removably connected to a first bone connecting means, a second
component operatively, removably connected to a second bone
connecting means and a guide means operatively connecting the first
and second components could be positioned external to the skin or
soft tissue of the mouth intraorally to effectuate distraction of
bone, such as, for example, the mandible. Such a device would have
the advantage of being initially much smaller, resulting in
considerable increased patient comfort because it is not necessary
for the initial device to be the length of the final distance to be
distracted, as with currently used devices, such as, for example,
the devices shown in FIGS. 11 and 14 in the article entitled
"Osteodistraction" mentioned above. Also, the device causes less
tissue displacement (lips) thereby reducing aesthetic concerns and
is better tolerated by the patient. Finally, the device is smaller,
due to its incremental construction, and, thus, easier to remove at
each intermediate position and at the end of the distraction
process.
[0116] Changes and modifications in the specifically described
embodiments and methods can be carried out without departing from
the scope of the invention which is intended to be limited only by
the scope of the appended claims.
Combination Distraction Dental Implant and Method of Use
Abstract of Disclosure
[0117] A combination distraction device and methods of using are
disclosed. The combination distraction device comprises a two
component portion (an apical and a coronal component) and an
expansion component for separating the two components once the
device has been initially integrated into the bone. Internal
threads of the apical and the coronal components are adapted to
operatively cooperating with the threads of the expansion component
such that the distance between the apical component and the coronal
component is selectively varied. When assembled, the expansion
component is advanced into the two separable components by
rotating, for example, the expansion component in a clockwise
direction. As the expansion component is advanced into the two
component portion of the combination distraction dental implant,
one end of the expansion component engages the end of the internal
thread in the apical component, causing separation between the
apical and coronal components thereby forming a gap. Since, when
placed in a patient, the apical and coronal components become
mechanically or biologically integrated, fused intra-osseously to
the bone, separating these two components expands a distraction gap
previously made in the bone proximal the separation point between
the two components and provides for the formation of new bone and
soft tissue.
[0118] The following represents additional language and/or
description from that of my prior application Ser. No. 08/886,078
filed Jul. 2, 1997.
[0119] FIG. 14 a perspective view of a lower jaw section 140 in
which a gum section 1 42 is recessed. One object of distraction
osteogenesis is to raise (from the perspective of the lower jaw)
the recessed bone and gum level so as to provide sufficient and
aligned bone support for a dental implant inserted in the jaw. In
accordance with this invention, the combination dental
implant-distraction device 144 (which is mechanically identical to
the distractor component shown in FIGS. 8A and 8B of my prior
application) is provided with a cylindrical head 146, an upper
threaded or longitudinal shank section 148 and a lower, smooth
walled and flat tipped, reduced diameter section 150. In the
embodiment of FIG. 14, the shaft segments 148 and 150 are
cylindrical, and the smooth shaft and tipped section 150 is reduced
in diameter with respect to upper threaded shaft section 148. A
central, hex-shaped blind bore 143 is provided which cooperates
with a suitably-shaped turning key to facilitate mechanical,
incremental rotation of the device, to promote distraction
osteogenesis.
[0120] In accordance with the method of this invention, the
unitary, i.e., one-piece, combination dental implant-distraction
device 144 is to be inserted in the jaw 140 of the patient. A
suitable drill is selected and used to predrill a bore into the
jaw, large enough to accommodate device 144, which is then inserted
in a conventional tapping and screw/rotation movement. A slight
undercut is provided so that as the combination dental
implant-distraction device 144 is inserted in the jaw, it is
relatively fixedly inserted therein with the threads
initially-turning into and bearing against the adjoining tissue,
which becomes compressed and deformed to accommodate the threaded
section 148 as it is threaded into the jaw 140.
[0121] In accordance with the principles of this invention, the
combination dental implant-distraction device is inserted far
enough into the jaw until its bottom, smooth, or flat-tipped
surface 152 bears against a corresponding flat or base surface 154
in the floor of the jaw, as it develops after the initial drilling
operation has occurred. This floor or base 154 of the jaw prevents
the bottom 152 of the dental implant-distraction device from moving
further downwardly as it rotates in the jaw. Rather, further
rotation will cause the tissue of the jaw to ride up the threads of
the combination dental implant-distraction device since the bone at
the base of the drilled bore blocks downward movement of the
device, even as rotation is accomplished. As a consequence of the
direction of the surgical cut, the new bone growth direction can be
adjusted, as desired, so that sinuses can be pushed upwardly.
[0122] In an alternative embodiment of FIG. 15, an additional base
support 156 in the form of a flat disc (similar in shape to a
washer) may be inserted in the drilled out, lower portion or blind
bore of the jaw upon which the bottom, smooth surface 152 of the
distraction device mechanically bears. By providing the additional
base support 156, there is believed to be less trauma to the
patient and greater likelihood that the dental implant-distraction
device 144 will not move downwardly in the jaw. The base member 156
could be constructed as the apical member illustrated in FIGS. 1
through 13 of my prior application or as the shown flat disc,
washer, or base member. The base member could, as an alternative,
be made of a resorbable material such as PLA or PGA which would
ultimately resorb into the jaw tissue after a suitable period of
time prior to which its usefulness as a base member would have been
fully realized.
[0123] In accordance with the method of this invention, and
referring to FIGS. 14 and 15, after the dental implant-distraction
device 144 is inserted in the jaw as illustrated in FIGS. 14 and
15, a surgical cut is provided to separate the upper jaw section
segment 158 from the remaining portion of the jaw section 160 along
a section line 162. This section line separates the jaw segment 158
from the remaining portion of the jaw section 160 and allows jaw
segment 158 to move upwardly incrementally in order to reestablish
a new upper gum line as ultimately illustrated in FIGS. 6 and 7 of
my earlier application. Distraction osteogenesis occurs in the gap
between the upper surface of the jaw segment 160 and the lower
surface of jaw section 158. As osteogenesis occurs, section 158
continues to be incrementally moved upwardly by rotation of the
dental implant-distraction device 144, as described. The tissue
rides up the inclinded surfaces of the threads of the device and
new bone is grown. In this manner, a new gum line is established
and a secure location is provided for a dental implant.
[0124] FIG. 16 is an enlarged sectional view illustrating the jaw
tissue 162 growing into the threads 164 and threaded or inclined
surfaces 166 of the threaded section 148 of the combination dental
implant-distraction device 144. Since there is sufficient jaw
tissue 164 bearing against the upper portions of the helix of the
threaded section 148, upper jaw segment 158 will move upwardly
because of the vertical forces imparted by the helical thread 166
on-the jaw tissue of upper segment 158 causing upper segment 158 to
move upwardly with respect to jaw section 160. This is possible
because the bottom 152 of the dental implant-distraction device
cannot move downwardly as it is fixedly bearing on the uncut jaw
section 154, as seen in FIG. 14, or on the bearing surface 156 as
shown in FIG. 15. Thus, incremental rotation of the device causes
upward movement of jaw section 162, riding up the inclined threads
of the device. This distraction will be filled in my bone
in-growth.
[0125] The above device and method eliminates the need for the
separate coronal and apical members 42 and 44, as illustrated in
FIGS. 1 through 13 of my prior patent application.
[0126] As may be easily understood, with this dental
implant-distraction device 144, only a single mechanical component
and surgical procedure is required to yield not only distraction
osteogenesis but also the sufficiently strong joining of the
implant 144 to the jaw 160 allowing a sufficient, sturdy platform
upon which a conventional dental crown or other dental prosthesis
may be placed as illustrated in FIGS. 1 through 13 of my prior
patent application.
[0127] FIG. 17 is a sectional view of another embodiment of my
invention in which a cap or cover 170 is employed which is adapted
to sit and frictionally fit over the dental implant-distraction
device 144. It provides a more hygienic and sanitary condition to
the procedure, during the time that the implant/distraction device
is being rotated to cause distraction osteogenesis to occur. The
cover or cap 170 may be frictionally secured or conventionally
secured but, of course, should be easily removable to allow access
to the head of the distraction device to permit easy selective
incremental rotation thereof. Thereafter, the cap can be easily
replaced. Another embodiment of the invention discloses the use of
a head protecting cap 179 which surrounds the hex head 181 of the
device. This cap, too, can be frictionally secured and is intended
to protect the tissue, at the device-tissue intersection from
debris.
[0128] In accordance with a further feature of this invention (See
FIG. 17), the center of the distraction device 144 may be provided
with a hollow, center bore 172 through the head and shaft, which
communicates with a plurality of radially extending branches 174
which exit the outside circumferential surface of the device. The
branches 174 directly communicate with that portion of the jaw
tissue which is closest to the distraction device. A syringe or
other material insertion device may be inserted into bore 172 to
dispense or apply BMP to the jaw tissue through the center bore and
branches 174 to enhance tissue healing. As the device accomplishes
distraction osteogenesis, the cap 170 will slowly ride off of the
device until it can be easily removed.
[0129] FIG. 18 is yet another alternative embodiment of the
combination dental implant-distraction device. Here, a basic
cylinder is provided, in which the center section 176 is smooth and
the outer longitudinal sections 178 are oppositely threaded. The
combination dental implant-distraction device of FIG. 18 is
employed in those situations in which an H-cut is surgically
provided to the jaw, permitting concurrent movement of upper and
lower jaw segments by their bearing against and riding over the
helical threads in threaded segments 178, as the dental
implant-distraction device is rotated. This embodiment would be
used, for example, where growth in two areas was desired, e.g.,
expanding the sinus area upwardly while also extending downwardly
the gum line of the upper jaw.
[0130] FIG. 19 is yet another alternate embodiment of the
distraction/connecting member. This, preferably, relates to the
three piece device fully described in my prior application. As can
be seen, one or more (preferred three radially-spaced)
anti-rotational grooves or fluted section(s) 202 are provided to
the upper threaded section 204. The fluted section(s) 202 enhance
bone in-growth. Bone in-growth has been found to be more effective
into smooth-walled transitional surfaces than sharp-walled or
cornered transitional sections. The section(s) 202, in the
preferred embodiment, extend to the bottom surface 206 of the
larger diameter section 208 and, preferably, extend at least 50% up
from bottom surface 206, of the axial length of the larger diameter
section 208. The head end 205 of the device is formed as a
wide-diameter disc, beneath the hex-head 207. The wide diameter of
the disc 209 and its flat bottom surface 211 ensure that the
implant remains immobile, i.e., the disc 213 inhibits rocking of
the implant.
[0131] While this invention has been described with respect to
mechanical threaded segments for vertically lifting jaw section for
distraction osteogenesis, it is also possible that a hydraulic or
other ratchet/lifting system could be employed to provide
sufficient bearing force or surfaces between the tissue and
respective distraction, coronal or apical members allowing the
segmented jaw section or the members in the embodiments to move
with respect to the jaw and/or distraction member. The relative
movement may be accomplished by a combination of a hydraulic
system, employed with a step-like vertical changer, much in the way
of a tire jack or the like. Similarly, the inventor envisions that
distraction osteogenesis could also be accomplished by a
telescopic, mechanical arrangement with the selective introduction
of fluid into connected chambers service to increase vertical
spacing to encourage bone growth. Other mechanical arrangements, of
course, could be employed to separate the segmented tissue, all
toward the desired end of bone growth and an implant support.
[0132] FIG. 20 shows yet another embodiment of the invention. Here,
similar to my prior disclosed three-piece device for a dental
implant and distraction mechanism, a unitary implant and distractor
200 is provided with supporting head 202 and downwardly extending
cylindrical shaft 204. The bottom 208 is a smooth-walled tip. Here,
too, a hex-shaped hole 206 is provided in the head to facilitate
incremental rotation of the device by a suitably shaped turning
key. Here, as described previously, the end of the shaft is
provided with a reduced-in-diameter smooth walled section 208. The
shaft 204 is externally threaded, as at 210. Beneath the head 202,
is a bevel or undercut surface 212. In this embodiment, however, a
separate collar or coronal member 220 is located extra-osseously.
The collar surrounds the cylindrically-smooth outer surface of the
superior or top portion of the device and mechanically functions as
the coronal member of my prior device. Thus, the surrounding cap
acts as the coronal member of my prior three component system, only
now the coronal member is extra osseous. As is apparent, the
coronal member can be intra- or extra-osseous. When the coronal
member is extra-osseous, the member protects the gum line from
becoming invaded with debris. This prevents infection. The
ring-like collar 220 is flat on its base, as at 222, which sits
atop the gum surface. The inventor contemplates that collars can be
formed of a variety of shapes and sizes to roughly match that of
the tooth around which the collar is placed. The shapes protect the
boundary, between implant and gum, from debris and bacteria. The
cap can be triangular, ovoid, box-shaped, depending on the desired
tooth shape. As distraction osteogenesis proceeds, the cap will
slowly "pop-off" and be discarded. Prior thereto, the cap has
promoted gum healing and protected the implant-gum linefrom
bacteria, infection and decay. The outside wall of the coronal
member 220 defines a cylindrical outer wall 224. The coronal member
220 is provided with internal threads 226 which mate with the
external threads 210 of the shaft 204 of the unitary dental implant
and distractor 200. The top surface of the coronal member 220 is
provided with an undercut 230 which mates and accepts the bevel
surface 212 of the head 202 of the dental implant and distractor
200. The device operates in much the same way as the prior
disclosed devices, namely, rotation of the device causes the
surgically sectioned jaw to move relatively upwardly, riding up the
inclined surfaces of the threads, with respect to the coronal
member. The coronal member will not rotate since it is provided
with one or more downwardly extending spikes (not shown in the
drawing) on its bottom or flat surface 222 which project into the
gum. This prevents rotation of the coronal member and ensures that
rotation of the shaft causes the sectioned jaw to move upwardly
with respect to the coronal member.
[0133] While this invention has been described with respect to
particular applications, it will be appreciated that the described
dental implant-distraction may be used for other purposes. Many
other variations and applications of the invention will be
apparent. The above specification and the detailed description of
the preferred embodiment are to be considered as representative
only, as the scope of the invention is intended to be covered by
the scope of the claims, as interpreted by the courts, and their
reasonable and legal equivalents, as also interpreted by the courts
and the applicable statutes. Changes and modifications in the
specifically described embodiments and methods can be carried out
without departing from the scope of the invention which is intended
to be limited only by the scope of the appended claims.
* * * * *