X-ray or gamma ray systems or devices – Photographic detector support – Dental
Patent
1983-06-14
1985-08-27
Church, Craig E.
X-ray or gamma ray systems or devices
Photographic detector support
Dental
378170, A61B 614, A61C 1900, G03B 4116
Patent
active
045382921
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a dental instrument comprising an X-ray film support connected to a bite block and, preferably, also an aligning rod. In prior art instruments of the type above defined the bite block is homogeneous and its top surface is parallel to its bottom. When a patient opens his mouth, the lower jaw swings around the jaw-joints. This means that an arbitrary point on the lower jaw substantially moves along a circular arc the radius of which equals the distance of the point from an axis through the jaw-joints. Consequently, the farther back the bite block has to be located, the greater will be the aperture angle of the jaws. It follows that, when a bite block has been inserted between the upper and lower tooth rows of a patient and the latter has, obeying the instructions of his dentist, again closed his mouth, only the rearmost teeth will contact the bite block whereas a vertical distance will be left between the block and the upper or lower teeth at the front edge of the block. The lack of contact between the bite block and all teeth overlying it means that it assumes an unstable position and may easily move in response to variations of the bite pressure exerted by a patient. Such movements lead to a displacement of the film support and hence of the film. As is understood, such a swinging movement of the bite block can occur both around an axis parallel to that of the jaw-joints and along a horizontal axis parallel thereto.
The instability problem above referred to is aggravated in the following two situations. The one situation is when the rearmost molars are to be X-rayed. In order for the bite block to be received between the teeth the patient then has to open his mouth that much that the only contact between the teeth and the bite block will be at the rear edge of the latter. The second situation is when one or more teeth are missing, so that even when the frontal teeth are to be X-rayed the bite block does not get sufficient support.
The X-raying of the frontal teeth involves a further difficulty. Due to the anatomy of the palate, the film, and consequently also the film support, will be pressed downwards which often leads to exclusion from the picture of the tissue regions around the teeth roots. When the frontal teeth of the lower jaw are X-rayed the tongue of the patient causes corresponding problems. For that reason conventional film supports can normally not be used in these regions.
The main object of the invention is to provide a dental instrument in which the problems above referred to are eliminated, meaning that once the patient has pressed his teeth against the bite block the latter will securely be retained in the position selected by the dentist.
Other objects and advantages of the invention will appear from the description and the drawings which illustrate three different embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing an instrument according to the first embodiment.
FIG. 2 is a cross-section taken along line II--II in FIG. 1.
FIG. 3 is a perspective view showing an instrument according to a second embodiment.
FIG. 4 shows the instrument of FIG. 3 in a lateral view.
FIG. 5 is a perspective view illustrating the third embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
The instrument shown in FIGS. 1 and 2 substantially consists of a film support 1 with a groove or recess 2 for the film 3. Film support 1 is integral with a bite block. The device sofar described represents prior art. However, according to the present invention, the bite block consists of two generally flat plate portions, hereinafter referred to as the upper portion 4 and the lower portion 5. The lower portion 5 is integral with the film support. Between block portions 4 and 5 there is a shallow gap. Further, upper portion 4 and lower portion 5 are spaced from each other except centrally, where they are interconnected via a thin bridge portion 6. In the embodiment shown in FIGS. 1 and 2 film support 1, the lower block portion 5, bri
REFERENCES:
patent: 1698795 (1929-01-01), Hillman
patent: 2123210 (1938-07-01), Schantz
patent: 2831978 (1958-04-01), Narvestad
Church Craig E.
Wieland Charles
LandOfFree
Dental instrument for optimal positioning of an X-ray film suppo does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dental instrument for optimal positioning of an X-ray film suppo, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dental instrument for optimal positioning of an X-ray film suppo will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2005907