Oral therapeutic apparatus and method of treating oral tissue during chemotherapy

An oral therapeutic apparatus and a method of using the oral device for treating a patient undergoing a chemotherapy treatment are disclosed wherein the oral device is formed to be insertable within the patient's mouth and receive a circulated cooling medium to continuously and uniformly cool the patient's oral tissues including the gums, cheeks, tongue, roof and base of the mouth, to prevent the oral tissues from absorbing the chemotherapy agent to thereby prevent inflammation and oral sores.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention is directed to an oral therapeutic apparatus comprising an 
oral device that is used to treat cancer patients undergoing chemotherapy 
treatments and a method of using the oral device. The oral device is 
formed to be insertable within a patient's mouth and receive a circulated 
cooling medium to cool the patient's oral tissues including the gums, 
cheeks, tongue, roof and base of the mouth, to reduce the absorption of 
chemotherapy agent. 
2. Description of the Related Art 
One of the most limiting side effects associated with chemotherapy 
treatments of cancer patients is the condition characterized by severe 
inflammation of the oral mucous membrane tissues known as mucositis. This 
inflammation produces oral sores that are so painful for the patient that 
frequently the chemotherapy treatments must be weakened or even 
discontinued before they are completed. As a result, cancer patients 
oftentimes can not be given the necessary amount of chemotherapy to 
effectively treat their conditions. 
It has been known, however, that keeping the oral tissues cold during 
chemotherapy treatments causes vasoconstriction of the associated blood 
vessels which reduces the amount of chemotherapy agent flowing into this 
tissue. The known method of cooling the oral tissues comprises 
periodically placing ice within the patient's mouth during the 
administration of the chemotherapy agent. This method lessens the 
formation of oral sores for short treatment periods of less than about one 
hour. 
Although the known method of cooling the oral tissues has been acceptable 
for short treatments, it is impractical for extended chemotherapy 
treatments that may continue for extended periods, for at least the 
following reasons. First, it is quite difficult for the patient to sleep 
because the rapidly melting ice must be constantly replaced. Second, and, 
more importantly, it fails to constantly and uniformly cool all of the 
oral tissues that are prone to form inflammation. The known method does 
not maintain the oral tissues at a constant desired temperature for the 
duration of extended treatments, and mucositis and oral sores inevitably 
form and become a limiting problem that forces the chemotherapy dose to be 
reduced or the treatment discontinued. Although the patient may be able to 
withstand the lessened chemotherapy treatment, its effectiveness is 
limited and the cancer may grow at an uncontrollable rate despite the 
treatment. 
Thus, in view of the inadequacies of the known method, there has been a 
need for an oral therapeutic apparatus, and a method of using the device, 
for effectively cooling selected oral tissues to reduce absorption of the 
chemotherapy agent and the subsequent formation of inflammation and oral 
sores, throughout extended periods of chemotherapy treatment. Such a 
device would reduce or eliminate the problem that have not been overcome 
by the known method and have reduced the effectiveness of previous 
chemotherapy treatments. Furthermore, there has been a need for an oral 
device that remains comfortable to the patient throughout the length of 
any treatment so that relaxation and even sleep can be obtained. 
SUMMARY OF THE INVENTION 
The present invention has been made in view of the above inadequacies of 
the prior art and has as an object to provide an oral therapeutic 
apparatus that comprises an oral device which is insertable in the mouth 
of a patient undergoing a chemotherapy treatment to prevent the formation 
of inflammation and oral sores, and thus enable the patient to receive 
full treatments at effective doses. 
It is another object of the present invention to provide an oral device 
which conforms closely to the patient's mouth so that the device remains 
comfortable to the patient during the treatment, and that receives a 
cooling medium which uniformly cools the oral tissues to reduce the 
absorption of the chemotherapy agent and subsequent formation of 
inflammation and oral sores. 
To achieve the objects of the invention, as embodied and broadly described 
herein, the present invention comprises an apparatus for reducing oral 
tissue inflammation of a patient being subjected to a chemotherapy 
treatment, which comprises an oral therapeutic device having an outer 
contour that conforms to the patient's mouth and contacts the patient's 
cheeks, gums, tongue, and roof and base of the mouth. The device contains 
a cooling medium which is preferably circulated therethrough by a supply 
source which maintains the cooling medium at the desired temperature to 
prevent warming of the device during the duration of the chemotherapy 
treatment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present invention will now be described in detail with reference to the 
drawings. 
FIG. 1 illustrates an oral therapeutic apparatus 8 in accordance with the 
present invention comprising an oral device 10 which is located within the 
mouth of a patient undergoing a chemotherapy treatment. As depicted in 
FIGS. 2 and 3, the therapeutic device is engaged by the upper and lower 
teeth, T, of the patient, and includes a tongue opening 11 in which the 
patient's tongue, T' is received. 
The oral device 10 is composed of a material that is pliable and 
biocompatible with the patient's oral tissues and can be used to form the 
device from an impression of the patient's mouth as will be described in 
greater detail below. Suitable materials include, for example, acrylic, 
plastic, silicon and rubber. 
The therapeutic device is formed by first making stone casts of the 
patient's teeth along with a bite registration. The casts are mounted on 
an articulator to simulate the patient's occlusal, and the articulator is 
adjusted to form a 4-6 mm vertical occlusal space. 
Next, a buildup is initiated with the preferred therapeutic device. A wax 
pattern is fabricated and added to the buildup, which pattern defines the 
inner and outer bladders and interconnection with the fluid inlet and 
fluid outlet. The preferred material is added to enclose the wax pattern 
as well as the entrance and exit of the tongue opening. The preferred 
material is allowed to harden or cure either at room temperature, or at an 
elevated temperature within a heating source such as a pressure pot. 
The hardened device is then placed in boiling water or within a hot 
atmosphere such as in an oven to melt the wax pattern, and the wax is 
poured out to produce a hollow device. The device is then finished, shaped 
and contoured. Finally, to assure that the outer surface of the finished 
device properly conforms to the contour of the patient's mouth, it is 
placed therein to verify an accurate fit. The device must fit comfortably 
and not extend so far into the patient's mouth that it causes the patient 
to gag. 
A cooling medium is supplied to the oral device at a desired temperature by 
a supply source 50. The supply source includes a pump for continuously 
circulating the cooling medium. The supply source further includes means 
for cooling the circulated cooling medium so that it is maintained at the 
necessary temperature to cool the oral tissues throughout the chemotherapy 
treatment. 
A fluid inlet tube 40 is connected at one end to a fluid inlet port 12 
formed at a front wall 13 of the oral device (see FIG. 3) and at the 
opposite end to the supply source 50. The therapeutic device is formed to 
contact and cool selected oral tissues within the patient's mouth. The 
cooling medium cools the therapeutic device which functions as a heat sink 
for heat generated in the oral tissues. The cooling medium is preferably 
circulated through the therapeutic device so that heat is continuously 
transferred away from the oral tissues and the device, to keep the oral 
tissues cold and prevent the device from significantly warming during the 
chemotherapy treatment. Significant warming of the therapeutic device 
would allow inflammation and oral sores to form and consequently force the 
treatment to be reduced or discontinued. 
Water is the preferred cooling medium because it has desirable heat 
transfer properties; however, other cooling mediums such as solutions of 
water and alcohol may optionally be used. Preferably, the cooling medium 
is maintained at a temperature of approximately 0.degree. C. to 
approximately 5.degree. C. 
In those instances when the cooling medium is circulated, it is caused to 
flow through the therapeutic device, and return to the supply source 
through the fluid outlet line 41 which is connected to the fluid outlet 
port 19 of the device (see FIG. 3). The supply source is preferably 
connected to a water line which provides a continuous supply of water. It 
may optionally contain a fixed supply of a cooling medium which is 
repeatedly circulated through the therapeutic device. 
For relatively short length chemotherapy treatments where warming of the 
therapeutic device is a less significant problem, the cooling medium may 
be enclosed in the oral device and not be circulated. In such instances, 
the therapeutic device may be filled with a cold fluid, and then sealed 
and placed within the patient's mouth. Alternatively, the cooling medium 
may be introduced into the device, which is sealed and cooled in a 
refrigerator or the like to the proper temperature. The cooling medium may 
be a non-toxic gel or a like substance that can maintain its initial 
temperature for the duration of the chemotherapy treatment. 
As illustrated in FIGS. 2 and 3, the oral device comprises an outer bladder 
14 which is spaced outwardly relative to a relatively smaller inner 
bladder 15. The outer bladder defines an outer cavity which includes a 
first outer chamber 16 and a second outer chamber 17 which are separated 
from each other by a barrier wall 18. The barrier wall extends between the 
fluid inlet and outlet ports and prevents the cooling medium from flowing 
directly between the outer chambers 16 and 17. 
The outer chambers 16 and 17 have a generally elongated cross-sectional 
shape, and extend rearwardly from the outer wall to the rear wall portions 
20 of the outer bladder 14. The outer chambers are spaced at a 
substantially constant distance from the outer surfaces of the side walls 
21 and 22, which contact the patient's respective cheeks, and follow the 
outer contour of the outer bladder. This constant spacing of the outer 
chambers assures uniform heat transfer away from the patient's cheeks to 
thereby reduce capillary size and subsequent inflammation of the cheek 
tissues to occur. 
The outer chambers communicate with upper and lower cavities 22 and 23 
located within the inner bladder 15. The cooling medium flows from the 
first outer chamber 16 into the first inner chamber through a first 
channel 24, and from the second inner chamber into the second outer 
chamber 17 through a second channel 25. The first and second channels are 
located within an intermediate bite portion of the device which is located 
between and integral with the outer bladder and the inner bladder as best 
shown in FIG. 2. The bite portion includes a top wall 26 and a bottom wall 
27, and is solid except for the two channels. The patient's upper teeth 
engage the top wall 26, and the associated gums contact outer surfaces of 
the inner and outer bladders, as shown in FIG. 2. Similarly, the bottom 
teeth engage the bottom wall 27, and the associated gums contact the outer 
walls of the inner and outer bladders. FIG. 3 illustrates the first 
channel 24 and the second channel 25 positioned between the patient's rear 
molars when the oral device is placed in the patient's mouth. 
The first and second inner cavities 22 and 23 are separated from each other 
by an inner wall 28 that is connected to the upper wall 29 and the lower 
wall 30 of the inner bladder. Intermediate the upper and lower walls, the 
inner wall is connected to an interior wall 31 that defines the tongue 
opening 11. As shown in FIG. 3, the inner wall is connected to the front 
wall 32 and the rear wall 33 of the inner bladder. 
The inner wall 28 includes a lower passage 34 and a vertically spaced upper 
passage 35 shown in FIG. 3, which are located proximate to the rear wall 
33. The passages are provided so that cooling fluid flows between the 
inner cavities at a controlled rate. The upper and lower passages are 
sized to assure an adequate rate of fluid flow between the inner cavities 
to constantly transfer heat away from the surrounding oral tissues. 
The flow pattern of the cooling medium through the apparatus and 
therapeutic device will now be described with reference to FIGS. 3 and 4 
which include arrows representing the direction of flow through the 
various portions of the device. After the therapeutic device is inserted 
in a patient's mouth, the supply source 50 is actuated to supply cooling 
fluid through the fluid inlet tube 40 and into the therapeutic device 
through the inlet port 12. The cooling fluid fills the first outer chamber 
16 and cools its surrounding wall 21, which contacts one of the patient's 
cheeks and cools the oral tissues thereof and also cools the gums along 
the upper and lower jaw. 
The cooling medium flows from the first outer chamber 16 through the first 
channel 24 and into the first inner cavity 22. It fills the first inner 
cavity and cools a surrounding portion of the upper wall 29 which contacts 
the roof of the mouth, a portion of the lower wall 30 which contacts the 
base of the mouth, and a portion of the interior wall 31 contacting the 
tongue. The cooled wall surrounding the first inner cavity also cools the 
patient's gums which are in contact therewith as shown in FIG. 2. The 
cooling medium flows through the lower passage 34 and upper passage 35 of 
the inner wall 28 and into the second inner cavity 23. The cooling medium 
cools the remainder of the wall of the inner bladder 15 and the interior 
wall 31. These wall portions cool the surrounding roof and base of the 
mouth, and the tongue as well as the adjacent gums. After the second inner 
chamber is filled, the cooling medium flows through the second passage 25 
and into the second outer chamber 17. The cooling fluid fills this outer 
chamber and cools its wall which contacts and cools the other cheek and 
the gums and exits the therapeutic device through the outlet port 19. The 
cooling medium returns to the supply source through the outlet tube 41, 
and is recirculated through the therapeutic device. 
In FIG. 4, the arrows, O, represent the general direction of fluid flow 
through the outer chambers, and the arrows, I, represent the general 
direction of fluid flow through the inner cavities. 
The therapeutic device in accordance with the present invention constantly 
and uniformly cools the patient's cheeks, gums, tongue, and roof and base 
of the mouth. Because it closely conforms to the contour of the patient's 
mouth, it can be used for extensive treatments without causing discomfort. 
Furthermore, its uniform and constant cooling action reduces or prevents 
the formation of inflammation and oral sores throughout extended 
chemotherapy treatments. 
The foregoing description of the preferred embodiment of the invention has 
been presented to illustrate the principles of the invention and not to 
limit the invention to the particular embodiment illustrated. It is 
intended that the scope of the invention be defined by all of the 
embodiments encompassed within the following claims, and their 
equivalents.