Patent Application
20060227939
The present invention is directed to a bite piece construction for use with dental equipment, and more particularly, is directed to a bite piece construction that is used in dental x-ray systems.
X-ray systems are commonly used in the dental industry to assist dental professionals. One type of a dental x-ray system uses a diagnostic panoramic technique to take a contiguous radiograph of the entire dentition of the jaw. The panoramic radiograph is achieved by positioning the patient between the x-ray source and a receiving radiosensitive surface. The x-ray source and receiving radiosensitive surface are maintained at a predetermined relationship from each other and revolved around the patient's head while the x-ray beam is continuously directed at the patient.
The x-ray source and receiving radiosensitive surface rotate in a path about a vertical axis and create a vertically orientated focal trough. The focal trough is positioned with relation to the patient's chin resting on a chinrest. Once the patient's chin position has been established, the x-ray system operator must ensure the patient's head is oriented correctly. To position the patient's head at a desired horizontal position, the patient's Frankfort plane is positioned horizontally. The Frankfort Plane is an imaginary line passing through the external ear canal and across the top of the lower bone of the eye socket, immediately under the eye. Similarly, the patient's head must be positioned at a desired vertical position, which is achieved by centering the patient's midsagittal plane vertically, the sagittal plane defining a longitudinal vertical plane that divides the mouth into two halves (left and right).
Failure to achieve correct vertical positioning results in the dental arch passing through the dental trough at an angle in the anterior region. The resulting image will be distorted in the anterior portion of the film through the maxillary and mandibular regions, causing foreshortening of the root tips, superimposition of the hard palate across the maxillary root tips, as well as blurriness to the dentition that extends beyond the edges of the focal trough. Failure to achieve correct vertical positioning also results in the dental arch not being laterally positioned (centered) within the focal trough. If the patient's head is not centered within the focal trough, one side of the arch will be closer and the other side of the arch will be farther from the film. This non-centered condition will result in an increase in magnification on one side of the image and a decrease in magnification on the other side. An additional negative result is an image containing an increase in the amount of inherent overlapping of the teeth due to the x-ray beam not passing perpendicularly through the dental arch.
A bite piece, also referred to as a bite block, is used to assist the operator to properly position the patient within the focal trough. This is achieved by having the patient bite down on the bite piece while resting her chin on the chinrest. However, conventional bite piece constructions can be large, cumbersome devices that are uncomfortable to use. Additionally, conventional bite pieces often have edges or abrupt changes in cross sectional profile which can obscure and significantly lessen the clarity, and therefore the quality of the radiograph.
What is needed is a bite piece for use with a dental x-ray device that is inexpensive to manufacture, comfortable to use, provides stability to secure the patient's head position and does not obscure the resulting radiograph.
The present invention relates to a bite piece for use with a dental x-ray system including a first portion extending to a second portion. An end of the second portion opposite the first portion has a region of reduced cross section adjacent the end, the region configured and disposed to be received between a patient's opposed upper and lower anterior teeth to secure the patient's head position during operation of the dental x-ray system, the region and the second portion substantially lacking a transitional edge.
The present invention further relates to a chin rest for use with a dental x-ray system including a body having a recess formed therein to secure a patient's chin thereon, the body having a slot formed therein adjacent the recess. A first portion extends to a second portion, the first portion being slidably received in the slot. An end of the second portion opposite the first portion has a region of reduced cross section adjacent the end, the region configured and disposed to be received between a patient's opposed upper and lower anterior teeth to secure the patient's head position during operation of the dental x-ray system, the region and the second portion substantially lacking a transitional edge.
An advantage of the present invention is that it can be inexpensively manufactured.
A further advantage of the present invention is that it provides a large lateral biting surface to provide improved stability.
A yet additional advantage is that the large lateral biting surface is of reduced thickness to provide improved patient comfort.
A still further advantage of the present invention is that it has a bite groove and bulb end profile angled away from the teeth bilaterally to alleviate patient teeth and gum discomfort associated with the patient biting on the groove.
An additional advantage of the present invention is it minimizes the erroneous projection of artifacts onto the radiosensitive film during operation of the x-ray system.
A further advantage of the present invention is that it reduces the amount of shadowing projected onto the radiosensitive film during operation of the x-ray system.
An additional advantage of the present invention is that it provides improved radiograph quality due to the contour of the bite piece and increased patient head position stability.
A still yet further advantage of the present invention is that it secures the patient's head position.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
One embodiment of a dental apparatus 10 having a bite piece 28 of the present invention is depicted in
Referring to
Referring to
The curved portion 34 preferably defines a curved path extending from the stop 38 at one end to a bulb 42 at the other end. Preferably, the degree of curvature of the curved portion 34 adjacent to the stop 38 is more pronounced, gradually extending to a substantially straight portion adjacent to the bulb 42. Preferably, the substantially straight portion is substantially horizontal for ease of access by a patient. To further provide improved patient access, circumferential groove 44 is formed adjacent to the bulb 42 having clearance regions 46 between the bulb 42 and the curved portion 34. It is intended that the patient bites down on the groove 44, the patient's upper and lower anterior teeth, or incisors, contacting the opposed sides of the groove 44. In a preferred embodiment, a reduced distance 58 between opposed sides of the groove 44 is shown in
Optionally, groove 44 is not circumferential. That is, as shown in
Further increasing patient comfort is the profile of the clearance region 46 between the bulb 42 and the curved portion 34. Preferably, the vertical plane 48 defines a clearance angle 50 between the vertical plane 48 and the adjacent surface of the bulb 42. Similarly, a clearance angle 52 is defined between the vertical plane 48 and the adjacent surface of the curved portion 34. In a preferred embodiment, clearance angles 50 and 52 are substantially equal, and the transitions between clearance angles 50 and 52 and adjacent surfaces of the curved portion 34 or bulb 42 are rounded. It is also preferred that clearance angles 50, 52 correspond to both the lower surface of the groove 44 and the upper surface of the groove 44. Clearance angles 50, 52 are configured to provide sufficient clearance between the patient's teeth and gums and the adjacent surfaces of the bulb 42 and curved portion 34. Preferably, the clearance angles 50, 52 can range from about 20 to about 50 degrees. It is to be understood that while clearance angles are shown between portions of the groove 44 and adjacent surfaces of the bulb 42 and curved portion 34, clearance regions 46 can be defined by any profile obtained by removing material between the bulb 42 and the curved portion 34 to form the resulting groove 44 which does not produce an edge that would cause discomfort to the patient.
The bite piece further includes a ridge 40 that extends outwardly from the curved portion 34 to assist in patient head alignment. The ridge 40, which is preferably located along the centerline of the upper surface of the curved portion 34, establishes the patient's midsaggital plane to properly align the patient laterally within the focal trough. In other words, the ridge 40 can be used as a visual alignment reference in conjunction with alignment features which can be a part of the x-ray system, such as a laser generated midsaggital line that is projected from the x-ray system.
While the cross sectional profiles of the curved portion 34 and bulb 42 define rounded cross sectional shapes, importantly, the rounded cross sectional shapes are substantially absent of sharp transitional edges. Since such transitional edges can introduce erroneous artifacts in the radiograph, the quality of the radiograph is improved. Further, in a preferred embodiment in which the cross sectional profile of the curved portion 34 and bulb 42 is elliptical, the quality of the radiograph is still further enhanced. This additional enhancement is due to the reduced cross sectional area of material through which the x-ray beam must pass. By reducing the amount of cross sectional area of the curved portion 34, including the bulb 42 and the groove 44, the amount of shadowing on the resulting radiograph is reduced, thereby increasing clarity of the radiograph.
Although the bite piece 28 can be constructed of any material compatible with x-ray exposure and patient use having sufficient material strength and stiffness, it is preferred that a polymer such as high density polyethylene (HDPE) is used. HDPE is fully recyclable and disposable. In addition, since HDPE is incapable of withstanding the temperatures associated with autoclaving, constructing the bite piece of HDPE restricts use of the bite piece 28 to a single patient.
Referring to
To control the relative rotational movement between the wands 134, a connecting member, such as a belt 145, is in simultaneous frictional contact with a portion of each of the cylinders 140, such as by extending around each cylinder 140 within a groove 147. The tension in belt 145 is sufficient to provide the desired frictional contact. By crossing the belt 145 over itself to form a figure eight configuration, one having skill in the art can appreciate that rotating one wand 134 an angle 138 away from a reference vertical axis 136 toward the other wand 134 similarly urges the other wand 134 to rotate toward the one wand 134 from its reference vertical axis 137. Reference vertical axes 136 and 137 are substantially parallel. Stated another way, wands 134 are configured to rotate at equal angles toward each other by virtue of frictional contact with the belt 145. By achieving symmetric rotation with respect to the vertical axes 136, 137, the respective ends 135 of each wand 134 are brought toward each other to orient a patient's head in a centered position, thereby achieving a consistent, repeatable positioning system. In other words, upon the end 135 of each wand 134 contacting opposite sides of a patient's head, the patient's head is secured in a centered position to provide an optimal, repeatable position for obtaining a dental radiograph. A small amount of compressive force is desirable to maintain the wand ends 135 in contact with the patient's head. This can be easily achieved with a torsion spring (not shown) or other similar device. That is, the torsion device urges the ends 135 of the wand 134 toward each other.
While the compressive force of the ends 135 of the wands 134 toward each other is desirable once the patient's head is positioned on the chinrest 16 and the dental apparatus 10 is operating, this is not always the case. In other words, when the patient's is initially being positioned on the chinrest 16, it is not yet desirable that the ends 135 of the wand 134 are positioned adjacent to each other, as the patient's head must first be positioned between the wands. It is desirable to have a detent, such as a spring loaded plunger 154 to lock the rotational orientation of the wands 134 in a position wherein the ends 135 are sufficiently spaced so that the patient can place her head between the wands 134. Once the patient has positioned her head on the chinrest 16, the detent can then be placed in an unlocked position, permitting the ends 135 to rotate toward each other to secure the patient's head as previously discussed.
Alternately,
The spring 180 and linking member 206 are sized to urge the aperture 202 of plate 198 into rotation toward plate 199. Similarly, by virtue of the connecting rod 182, the aperture 204 of plate 199 is urged into rotation toward plate 198. Further, the rotations of plates 198, 199 (and wands 134) are substantially equal and opposite as that previously discussed. However, the detent feature as shown in
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
