U.S. patent application number 10/279578 was filed with the patent office on 2003-03-27 for positioning apparatus and method for transversal dental x-ray tomography.
This patent application is currently assigned to DENTSPLY Research & Development Corp.. Invention is credited to Molteni, Marcello, Regalia, Gaetano.
Application Number | 20030058988 10/279578 |
Document ID | / |
Family ID | 22569338 |
Filed Date | 2003-03-27 |
United States Patent
Application |
20030058988 |
Kind Code |
A1 |
Molteni, Marcello ; et
al. |
March 27, 2003 |
Positioning apparatus and method for transversal dental x-ray
tomography
Abstract
An apparatus and method used in dental transversal x-ray
tomography provides off-line alignment of the patient denture
impression with the bite block of a panoramic x-ray equipment, and
allows accurate and reproducible patient positioning during the
imaging process. An impression of the patient denture is taken on a
special tray. The tray is mounted on the alignment apparatus and is
aligned by using optical marking in correspondence with the target
zone. The alignment apparatus is then mounted on a panoramic x-ray
equipment, and the patient is invited to bite on the tray during
the imaging process.
Inventors: |
Molteni, Marcello; (Milano,
IT) ; Regalia, Gaetano; (Milano, IT) |
Correspondence
Address: |
Douglas J. Hura
DENTSPLY INTERNATIONAL INC.
570 West College Avenue
York
PA
17405-0872
US
|
Assignee: |
DENTSPLY Research & Development
Corp.
|
Family ID: |
22569338 |
Appl. No.: |
10/279578 |
Filed: |
October 24, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10279578 |
Oct 24, 2002 |
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10074880 |
Feb 12, 2002 |
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10074880 |
Feb 12, 2002 |
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09679765 |
Oct 5, 2000 |
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6424694 |
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60158705 |
Oct 8, 1999 |
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Current U.S.
Class: |
378/38 |
Current CPC
Class: |
A61B 6/14 20130101; A61B
6/04 20130101 |
Class at
Publication: |
378/38 |
International
Class: |
A61B 006/14 |
Claims
What we claim is:
1. A device for positioning a patient for the taking of a dental
x-ray, comprising: a support bar removably affixable to a dental
impression tray, and means to adjust the position of said support
bar in at least one direction in relation to the desired x-ray
location.
2. A device as in claim 1, wherein said means to adjust includes a
rotatable support rod affixed to said support bar.
3. A device as in claim 2, wherein said rod is provided with means
to adjust the position of said support bar axially along the length
of said rod.
4. A device as in claim 3, wherein said means to adjust includes a
clamping means.
5. A device as in claim 1, further comprising an icon guide having
at least one icon and removably positionable in a spaced opposing
relation to said impression tray when said impression tray is
affixed to said support bar.
6. A device as in claim 5, wherein said icon guide is at least
partially transparent.
7. A device as in claim 1, further comprising means to removably
mount the device on an x-ray machine.
8. A device as in claim 7, wherein said means to mount includes a
block carried by the device and receivable within a slot carried by
the x-ray machine.
9. A device as in claim 8, further comprising in combination, a
remote support also carrying a slot for selectively receiving said
block.
10. A device as in claim 1, wherein said means to adjust includes
an arcuate shaped slot carried by a base member, such that the
arcuate position of said support bar can be adjusted.
11. A device as in claim 10, wherein the device further comprises a
pin means receivable within said arcuate slot, and means to
removably restrict movement of said arcuate slot in relation to
said pin means.
12. A device as in claim 11, wherein said pin means is a threaded
screw, and said means to restrict is a thumbscrew.
13. A device as in claim 1, further comprising a sub-base members
having at least one track, and wherein said support bar is
supported upon at least one leg member, wherein said at least one
leg member is in turn supported by a base member having a runner
receivable within said track, such that the horizontal movement of
said runners within said tracks is permitted, thereby allowing a
corresponding movement of said support bar.
14. A device as in claim 13, wherein the position of said runner
within said track is securable in a selected location by use of an
affixing means.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of Ser. No. 09/679,765
filed Oct. 5, 2000 (Case GEN-702) which claims the benefit of U.S.
Provisional Application Serial No. 60/158,705 filed on Oct. 8, 1999
(Case GEN-702 PRO).
TECHNICAL FIELD
[0002] The present invention includes a positioning apparatus for
use with transversal dental x-ray tomography. More particularly,
the invention relates to a device which employs a dental impression
held within an impression tray, and which aligns an x-ray shot by
use of the impression.
BACKROUND OF THE INVENTION
[0003] Dental x-ray transversal tomography or scanography, is a
projection modality provided by modern dental panoramic x-ray
equipment for imaging the jaw in the transverse direction. Such
images in the dental practice by using panoramic x-ray equipment is
useful, especially in implantology, and compares with the
tomographic imaging which can be obtained with much more complex
and expensive tomographic equipment.
[0004] In combination with such imaging by using panoramic x-ray
equipment, it is extremely important to provide an accurate and
reproducible positioning of the patient. Transversal tomography
equipment is capable of producing precise and accurate x-ray
images. However, it has been found that it is often difficult to
properly align the patient to take full advantage of the potential
precision of the x-ray apparatus.
[0005] A method of aligning a patient is disclosed for example, in
U.S. Pat. No. 5,444,754. The method includes imaging cross-sections
on the same film as a respective longitudinal image of the dental
arch. The cross-sectional images are exposed to include
identifications for the sections. U.S. Pat. No. 5,431,162 employs a
stent aligned with the imaging device so that a mark on the stent
is aligned with a light beam. This patent also describes an
exemplary x-ray machine, which disclosure is hereby incorporated by
reference.
[0006] A need exists for an improved apparatus and method for
properly aligning a patient when taking a transversal tomography
x-ray image. The apparatus and method should naturally include ease
of use and comfort to the patient.
SUMMARY OF THE INVENTION
[0007] It is therefore, an object of the invention to provide an
apparatus and method for transversal dental x-ray tomography,
allowing off-line alignment of the patient denture impression with
respect to the biting point of a panoramic x-ray equipment, and
accurate and reproducible patient positioning on-the-equipment
during the imaging process.
[0008] The apparatus is a mechanical alignment device comprehending
supports and joints, and is based on the following components and
features:
[0009] A support tray, over which standard impression material is
hardened to provide the reproduction of the patient denture at the
occlusal plane.
[0010] The tray can either be a standard commercially available
dental tray for impression, or a custom made tray for this
application.
[0011] A positioner, holding the tray with denture impression, and
fitting into the bite block holder of the panoramic x-ray
equipment. The positioner is provided with slides and joints,
allowing off-line free adjustments of the denture impression
support: linear movement in the X and Y direction, rotation around
X and Z axis.
[0012] A graduated scale in mm and degrees is provided for each
adjustment movement. Transparent guide plates with silk screen
reference of the target sections and teeth icons, allowing
positioning of the region of interest with respect to the same
target sections.
[0013] The first transparent plate is dedicated to the upper
dentition, the second to the lower dentition.
[0014] A workbench support, provided with base, column and
fastening screw, on which the positioner is mounted during the
off-line adjustment phase.
[0015] The positioner is mounted upside for upper jaw and downside
for lower jaw.
[0016] The method is articulated in several steps as follows:
[0017] (1) The patient bites the impression material to reproduce
the denture occlusal plane (upper or lower jaw, using different
denture support). A marker (steel ball or gutta-percha cone) can be
introduced into the impression, in correspondence with the region
of interest.
[0018] (2) The positioner is placed on the workbench (upside for
upper jaw, reversed for lower jaw), and the tray is mounted on the
positioner.
[0019] (3) For upper jaw the tray is adjusted perfectly in the
horizontal plane, for lower jaw a slight adjustment of the tray
below the horizontal plane is allowed.
[0020] (4) The transparent guide plate is mounted on the
positioner.
[0021] (5) The tooth icon is aligned with the diagnostic target
zone on the impression, by using the vernier slides (X, Y axis) and
the rotation around the Z axis.
[0022] (6) The tray position is fixed by securing the corresponding
fastening screws.
[0023] (7) The panoramic x-ray equipment is prepared for
transversal tomography.
[0024] (8) The positioner with the support tray is mounted on the
bite point of the panoramic x-ray equipment.
[0025] (9) The patient is invited to bite into the impression to
ensure a firm positioning, and then the imaging process is
started.
[0026] The apparatus is designed to accommodate critical patient
morphology, as derived by anatomical studies extended to patients
of various race, age, and sex.
[0027] These and other objects of the invention, which will become
apparent from the following description, are carried out by the
invention as hereinafter described.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 shows the positioning apparatus of the present
invention secured within a workbench support;
[0029] FIG. 2 shows a perspective close-up view of a transparent
icon guide of FIG. 1;
[0030] FIG. 3 is a photograph showing a workbench support and a
positioning device according to the invention.
[0031] FIG. 3 is a prospective view of an alternative icon
guide;
[0032] FIG. 4 is a partially exploded, perspective view of the
apparatus of FIG. 1;
[0033] FIG. 5 is a photograph showing a dental impression formed
within impression material in a dental impression tray, and the
tray is positioned upon the positioning apparatus of FIG. 1;
[0034] FIG. 5a is a close up view of the impression tray of FIG.
5;
[0035] FIG. 6 is a top, plan view of the apparatus of FIG. 1;
[0036] FIG. 7 is a perspective view of the combination shown in
FIG. 4, shown being employed with a patient;
[0037] FIGS. 8, 9, 10 and 11 are a series of photographs showing
the relative freedom of movement obtainable with the positioning
apparatus of FIG. 1.
PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION
[0038] A positioning apparatus according to the concepts of the
present invention is shown by way of example in the drawings by the
number 10. Positioning apparatus 10 includes a universally
adjustable holder 11 that can be selectively positioned upon a
workbench support 12 or a dental x-ray machine 12a (FIG. 7). Holder
11 is provided with an attaching element 13 for affixing a standard
dental impression tray 14 thereto. By "universally adjustable" it
is understood that holder 11 is provided with multiple adjusting
mechanisms (to be more fully described below) that allow the
affixed impression tray 14 to be moved in at least one of and
preferably all of an x, y and z coordinate direction.
[0039] Positioning apparatus 10 is also provided with a removable
transparent icon guide 20. Icons 21 are provided upon guide 20,
such that when guide 20 is affixed to positioning device 10, at
least one icon 21 is positioned generally in a spaced opposing
relation to impression tray 14 also affixed to positioning device
10.
[0040] The user employs impression tray 14 to prepare an impression
of a dental arch or a desired portion of a dental arch in a
conventional manner. The taking of dental impressions is well known
and need not be described here. The impression material, shown by
number 22 in FIG. 5, is allowed to at least partially set.
Impression tray 14 is then affixed to positioning device 10 (in a
manner to be described below) and icon guide 20 is affixed to
positioning device 10 in the spaced, opposing relation previously
described. By universally adjusting the position of impression tray
14, an icon 21 can be caused to be in a specific position relative
to impression tray 14 and hence to a specific and selected part of
the dental arch. The adjusting mechanism is then locked into that
position and the icon guide 20 is removed. The positioning
apparatus 10 is then affixed to the x-ray machine 12a and the
patient is invited to bite onto the dental impression 22 still held
within impression tray 14 (FIG. 5).
[0041] In this manner, the resulting x-ray image will be taken at
the precise location indicated by the positioning of icon 21 during
the set-up described hereinabove. The resulting x-ray image is
precisely aligned.
[0042] FIG. 1 shows positioning device 10 in place upon workbench
support 12, where the steps of aligning impression tray 14 with
respect to an icon 21 carried by icon guide 20 can be accomplished.
A second icon guide 24 is shown in FIG. 2. Icon guides 20 and 24
may be alternatively useful for example in taking adult x-ray
images, pediatric images, anterior or posterior shots, partial
images, or the like. It will be understood that any such icon guide
is within the scope of the invention.
[0043] FIG. 5a shows a substantially standard dental impression
tray. Such trays and their use are well known in the art. The only
requirement for an impression tray being useful in combination with
the present invention is that there must be some means to affix,
and more preferably, removably affix impression tray 14 to
positioning device 10, which will be discussed more fully
hereinbelow.
[0044] FIG. 5 shows positioning device 10 in place upon workbench
support 12 and with means to affix an impression tray 14. Further,
a formed impression 22 is held within impression tray 14. Further
still, transparent icon guide 20 is affixed to positioning
apparatus 10 in the aforesaid spaced, opposing relation to
impression tray 14. Icons 21 are carried by icon guide 20, and
because icon guide 20 is transparent, a user can see through icon
guide 20, such that as impression tray 14 is adjustably positioned,
the user can see through icon guide 20 and adjust the position of
impression tray 14 so that a specific portion of impression 22 is
directly opposed with an icon 21. Icon 21 may be thought of as
being a "cross-hairs" in regard to function, although there is no
intention to indicate a specific shape of icon 21. Icon 21 can be a
dot, a line, a circle, an oval, a square, a triangle, a trapezoid,
a letter, a number, any regular or irregular shape, a
representation of a tooth or teeth or other dentition, a series of
any such articles, or any other indicia that may be desired or
useful. Icon 21 may be painted, silk-screened or otherwise placed
upon guide 20 or 24 as shown in the drawings. Although not shown,
icon 21 could also be a decal, an etching or some other physical
structure such as a hole, a post, a pin, or the like, or a
combination of any of these mentioned.
[0045] FIG. 7 shows the positioning apparatus 10 of the present
invention in place upon an x-ray machine 12a and wherein a patient
30 is biting upon the impression 22 held within impression tray 14.
While the present invention has particular application to dental
x-ray transversal tomography, and as such can be used with such an
x-ray machine, it also has application to any dental or even other
medical x-ray machines or stand. Therefore, any conventional x-ray
machine is within the scope of the present invention. It is merely
required to provide a means of affixing apparatus 10 to the x-ray
machine 12a, such as by using a conventional hand-held 31
configured to be affixable to apparatus 10, or any other
conventional method.
[0046] FIGS. 8-11 show the range of movement facilitated by
positioning apparatus 10. Positioning apparatus 10 is shown in FIG.
1, removably affixed to workbench support 12. Positioning apparatus
10 in FIGS. 8-11 does not have an icon guide 20 or an impression
tray 14 in place, so that the range of adjustable movement of
positioning device 10 can be more clearly seen. However, there is
shown one means of mounting impression tray 14 to positioning
apparatus 10. This includes support bar 40 which is removably
affixable to impression tray 14. In the embodiment of the invention
shown in the drawings, bar 40 includes first and second prongs 41
and 42, respectively. Prongs 41 and 42 can be inserted into a slot
43 (FIG. 5) to hold and support impression tray 14.
[0047] For the sake of this discussion with respect to FIGS. 8-11,
the range of adjustable motion of positioning apparatus 10 will be
described with respect to support bar 40. It is understood that
when an impression tray 14 is affixed to positioning apparatus 10,
such as by use of support bar 40, the impression tray 14 will
likewise be adjustable as to its position. With this in mind, FIGS.
11, 11a and 11b show a reciprocal, horizontal motion achievable
with the adjusting devices of the positioning apparatus 10.
[0048] FIG. 8 shows an articulate adjustable position and shows
that the support bar 40 can be adjustable from an upright position
to a position 180.degree. therefrom, or any position
therebetween.
[0049] FIG. 9 shows a horizontal position substantially
perpendicular to the adjustable position shown in FIG. 11. It would
be appreciated, that the positioning shown in FIGS. 8-11, can be
achieved for example by vernier adjusting mechanisms, although any
adjusting mechanism is within the scope of the invention.
[0050] For example, support bar 40 may be adjustably affixed to a
support rod 50, which in turn is supported on legs 51. A threaded
clamp mechanism 52 is affixed to support 40 such that as support 40
is horizontally positioned along support rod 41, it can be locked
into place, such as for example, by turning knob 53. Knob 53
thereby creates a simple compression fitting, which when removed
allows freedom of movement of support rod 40 along support rod 41.
Preferably, knob 53 is a thumbscrew threadably engageable with bar
40 through a slot 54 in rod 41.
[0051] Support rod 41 is also rotatable such as for example, on
axle nut 60. Threaded knob or thumbnut 61 is provided on at least
one end of support rod 41, and, when tightened, draws support rod
41 into physical contact with a leg 42 (depending upon with which
leg it is associated), thereby restricting the freedom of rotation
support rod 41 upon axle 61. Thus, the rotational position of
support rod 41 can be obtained and removably affixed.
[0052] FIG. 1 also shows a support block 70 which can be used to
removably affix positioning apparatus 10 to alternatively and
selectively, workbench support 11 and a desired x-ray machine 12a.
By providing a slot, such as slot 71 (FIG. 4) positioning apparatus
10 can be placed within workbench support 11 and by providing a
similar slot upon an x-ray machine 12a, positioning device 10 can
be also positioned upon and in conjunction with the x-ray machine
12a. Another thumbscrew 72 can be provided in support 11 to secure
it in position in a conventional manner.
[0053] Another vernier adjusting mechanism 80 is shown which can be
used to carry out the horizontal adjusting as shown in FIG. 10.
FIG. 11 also shows the horizontal adjusting mechanism 90 which can
be used to position support bar 40. Base member 81, preferably
physically supporting legs 51, may be arcuate in shape, or at least
carrying arcuate slot 82. Apparatus 10 also carries sub-base 83,
having pins or screws 84, receivable within arcuate slot 82. Thus,
base membe 81 can be adjusted in the arcuate manner shown by arrows
85a, 85b and 85c in the drawings (FIG. 10). A thumbscrew 86 may be
used to secure base member 81 in any selected location.
[0054] As shown in FIG. 11, sub-base 83 may be supported on
apparatus 10 by runners 91 received in tracks 92. Horizontal
movement is allowable as represented by arrows 93a, 932b and 93c by
movement of runners 91 within tracks 92. Thumbscrew 94 may be
threadably engaged with sub-base 83 to secure it in a desired
location. Indicia 100 may be used on apparatus 10 to help align any
of the vernier adjustments discussed hereinabove.
[0055] FIGS. 2 and 3 shows icon guides 20 and 24, showing support
legs 110, 111 and pins 112 and 113. It will be appreciated, that
pins 112, 113 fit within apertures 120 to position icon guide 20 or
24 upon positioning device 10 as shown in FIG. 1. Any means of
removably affixing icon guide 20 or 24 is within the scope of the
invention. It is appreciated that the present invention provides
advantages including: Reproducibility, and comfort of the patient;
all critical factors to ensure the success of the examination,
which is inherently complex.
[0056] The apparatus can be used off-line, with minimised
disturbance for the patient. The positioners offers wide range of
adjustments, in the X and Y linear movements, and in the X and Z
axis rotation, for the optimal adjustment of the occlusal plane
both for upper and lower jaw.
[0057] The alignments are simple and accurate, optically guided by
gauges and scale indications for optimal reproducibility of the
examination.
[0058] The device can either use standard trays commercially
available, or specifically designed trays.
[0059] The trays with the impression can be re-used, which is
useful in case of required repetition of the examination at a later
time.
[0060] The apparatus offers two operation modalities for the
positioning of the patient: The first by using the trays with the
impression, where the patient is positioned by biting on the same
impression.
[0061] The second by using a bite piece, alternative to the tray,
and positioning the patient by means of conventional centring
lights referred to the alatrago plane (upper jaw) or by placing the
mandible in the horizontal plane (lower jaw).
[0062] Panoramic x-ray equipment executes the imaging according to
the invention by using the linear tomographic technique.
[0063] Multiple programs are available for anterior dentition
(incisors) left and right, and for posterior dentition left and
right.
[0064] Multiple views are made of the region of interest, displaced
preferably by 7 mm in parallel planes.
[0065] The thickness of the tomographic layer is selectable between
preferably 3 and 6 mm.
[0066] It should therefore be apparent that the positioning device
as described herein carries out the object of the invention and
otherwise provides an advance and contribution to the art. The
invention has been exemplified with respect to drawings and
description, without an attempt to provide a depiction or
description of every embodiment of the event of device or method.
Those skilled in the art will readily understand that various
sizes, components and method steps can be employed and still fall
within the scope of the present invention.
* * * * *