CA2074074A1

CA2074074A1 - Device for measuring the wearing time of a removable denture

Info

Publication number: CA2074074A1
Application number: CA 2074074
Authority: CA
Inventors: Hermann-Josef Frohn
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-02-10
Filing date: 1991-01-15
Publication date: 1991-08-11
Also published as: JPH05504278A; EP0513032A1; WO1991011969A1; DE4004048C1

Abstract

A removable denture (1) with a holding device for fastening the denture in the mouth contains an encapsulated device (18) for measuring the wearing time. The encapsulated device has at least two connections (22, 23, 24) which can be connected to an external evaluation device for determining the wearing time. The connections are exposed in the buccal cavity and are readily accessible. The dentist can connect the evaluation device to the exposed connections (22, 23, 24) with suitable clips and read the output signals from the device (18) for measuring the wearing time. The connections are the clamping or fastening elements (17) of the device, which are electrically insulated from each other.

Description

2 ~ 7 ~ ~ 7 ~

PCT/EP91/00050 Sg/Dt Removable orthodonti~ aPParatus ~changed into: Device for measuring the wearing time of a removable denture) The invention is directed to a removable orthodontic apparatus according to the preamble of claim l.

, For a successful orthodontic treatment, the cooperation of the patient is of decisive importance. For judging the success of a treatment performed by use of an orthodontic apparatus, it is required that the wearing time of the apparatus can be objectively detected. Fur-ther, the motivational effect caused the awareness of the presence of a wearing time measuring device is of decisive importance and the compl.iance between the physician and the patient is lastingly improved. Thus, finally, the overall treatment can be carried out in a shorter time.~However, also in case of dental prosthet-ic apparatuses ~artificial denture), the physician in charge will take an interest in reliably detecting the actual wearing time. I~ a dentaL prosthetic apparatus i9 not regularly worn by a patient, the position o~ the I . residual teeth with xespect to each other can change and~or a~change of the emplacement of the prosthesis can occur so~that the dental prosthetic apparatus will ~' not sufficiently fit anymore and will di.s~urb the pa-:.

7 ~ 0 7 ~

tient. In this case, the patient who has not regularly worn the dental prosthetic apparatus might hold the physician responsi~le for a~ inappropriate treatment.
If, however, the wearing time of the apparatus could be detected objectively, the physician would not be sub-ject to the unjustified accusation of having performed an insufficient treatment. Just as in orthodontic treatment, it is also in treatment by use of dental prostheses that the employment of an electxonic wearing time measuring device has a considerable motivational effect on the patient, and the compliance between the patient and the physician is enhanced in a positive and lasting manner also in this case.

A known orthodontic apparatus (DE 28 20 358 C3) includ-ing a moulded plastic body comprises a wearing time measuring device making it possible for the physician in charge to precisely check the wearing time of the apparatus in the mouth of the patient. The wearing time measuring device includes a pulse generator and an electronic couhter. The pulse generator and the counter are activated by a sensor for detecting whether the apparatus is kept in the mouth. During the wearing time, the pulse generator delivers pulses to the coun-ter which are added and stored. By occasional inter-rogating of the counted value by an external evaluation ~ means, the wearing kime can be detected and displayed~
iI The measuring device is accommodated in a cavity of the moulded plastic body, said cavity being sealed against moisture by means o~ a plate.
,j , 1 A disadvantage re~ides in that the interrogation of the ¦ wearing time of the oxthodontic apparatus is relatively complicated and time-consuming. Notably, for checking the wearing ime, the cavity of the moulded plastic .;: :
- : :

:: ' ~.

:~ . :, : . , , . : .: .. . ... : :

2~7~7~

body containing the wearing time measuring devlce has to be opened and the wearing tim~ measuring device has to be removed and connected to the external evaluation means. After interrogating the data, the wearing time measuring device is returned into the cavity which again must be sealed against moisture.

It is an object of the invention to provide a removable dental app2ratus of the type mentioned n the preamble of claim 1 which allows uncomplicated and ~ast inter-rogation of the waaring time.

According to the invention, the above object is solved by the features inàicated in ihe cnaracterizing part OI
claim 1.
, In the wearing time measuring device of the invention, the connectors adapted for connection with the external evaluation means are exposed and thus ar~ accessible without complicated or time-consuming preparatory work.
For xeading out the data from the time measuring de-vice, all the physician in charge has to do is connec~
the evaluation means to the.~exposed connectors by suit-able clamps. Since the exposed connectors are exposed . . .
to the mouth region, the signal output of the wearing time measuring device is provided to be short-circuit-proof. Thus, malfunction of the wearing time measuring device is excluded.
I , ~ Advantageously, the output signals of the wearing time `il measuring device axe not applied to the signal output during the wearing time of the orthodontic apparatus.
De~ection~of th~e wearing time in the wearing time measuring device is perormed by at least one sensor which is re~ponsive e.g. to moisture, temperature --4 _ 2 ~ 7 ~

and/or contact pressure. As long as this sensor detects the presence of the orthodontic apparatus in the mouth, it supresses the output of data. To this purpose, the wearing time measuring device is suitably provided with an output control unit for interrupting the transmis-sion of output signals to the signal output during the wearing time and thus precluding undesired current flow between the connectors exposed to the mouth region of the patient. Only when receiving an interrogating sig-nal, the output control unit will apply the output siy-nals to the signal output. The output control unit is connected to the weariny time measuring device only after the orthodontic apparatus has been taken out of the patient's mouth.

The signal output of the wearing time measurlng device and the control input of the output control unit are preferably located on the same connectors so that the nun~er of connectors within the mouth region is re-duced. Data transmission between the wearing time mea-suring device and the external evaluation means can be pexformed via a sole bidirectional channel which is used for transmission of the interrogating signal emitted from the evaluation means as well as of the output signals ~of the wearing time measuring device to e received by t~e evaluation means.
. , When using dentures, particularly orthodontic appara-tuses having a holding device consisting o~ a plurality j o~ fastening elements electrically insulated ~rom each other, the metallic fastening elements are suitably , . ..
utilized as connectors. The fastening elements serve bo~h for locking the~orthodontic apparatus to the teeth of the ~patient an~ for connection o~ the evalua~ion means. Thus, there is no need for additional connectors :

~. .. ~ - . . . . . .

2 ~

which could ~e disturbing while wearing the orthodontic apparatus and whereon bits of food could become attach-ed during eating. Further, it becomes easier to estab-lish the connection between tha orthodontic apparatus and the wearing time measuring device. When assembling the apparatus, the dental technician only has to con-nect the output of the wearing time measuring device via flexible connecting wires to the metallic fastening elements and to cast he wearing time measuring device together with the connecting wires and the ends of the fastening elements into a sealing compound. Also, the fastening elements are always easily accessible so that connection of the evalutation means can be performed quickly by suitable terminal clamps.

In dentures, particularly orthodontic apparatuses com-prising a moulded body with a plurality o~ clamping elements - electrically insulated from each other -for adjustment of the teeth, the metallic clamping ele-ments can form the connectors. The wearing time measur-ing device is suitably encased moisture-proof in the moulded body.

Advant~geously, there are provided three connectors, the f.irst connector among them being connected both to the signal output of the wearing time measuring device and the control input of the output control unit. The second connector can have a moisture de~ector connec~ed thereto which is integrated in the wearing time measur-ing device. The moisture detector activates the wearing time mea~uring device as soon as the orthodontic ap-paratus has been placed into the mouth of the patient and there has been de~ected a current flow, caused the moisture, between the second connector and the third connector having ground potential applied thereto. The .

, :

- 6 - 2~

connectors ar~ suitably marked for excluding confusion when connecting the evaluation means.

The removable orthodontic apparatuses into which wear-ing time measuring devices can be integr~ted for ob-jective detection of the wearing time, are meant to comprise orthodontic apparatuses which compensate posi-tional anomalies of the teeth and anomalies of the jaws and are removable from the mouth of the patient, as well as removable dental prosthetic apparatuses. On the one hand, the dental prosthetic apparatuses serving,as artificial teeth can be partial prostheses supported on the residual teeth of the patient or can be complete upper-jaw or lower-jaw prostheses to be placed into the toothless upper or lower jaw. On the other hand, the wearing time measuring device can also be mounted in profiles for the protection against gnashing which are used in case of sliding obstruction in the patient's set of teeth.

Embodiments of the invention will be described in greater detail hereunder with reference to the draw-ings~

Fig. 1 shows a plan view of a removable orthodontic apparatus having a moulded body enclosing the wearing time measuring device, with the clamp-ing elements of th~ moulded body forming the connectors, , ~'1 Fig. 2 shows a block diagram of the output stage of the wearing time measuring device, : ., ; Fig. 3 shows a plan view of a removable orthodontic appaxatus without the moulded body, , , , :

, ~' : :

~ ::` 2~7~ ~7'~

Fig. 4 shows a plan view of a removable orthedontic apparatus without the moulded body, to be fastened by an external holding bracket to the head of the patient, Fig~ S shows a plan view of a removable orthodontic : apparatus together with residual teeth, with the fastening elements of the apparatus forming : the connectors, and `:

Fig. 6 shows a plan view of a removable orthodontic apparatus (complete upper-jaw prosthesis~ hav-ing a moulded body enclosing the wearing time measuring device.
' . .
The orthodontic apparatus 11 shown in Fig. l is fasten-ed to the teeth 12 of the upper jaw. The orthodontic apparatus 11 comprises two moulded body halves 13,14 consisting of plastic and being connected to each other by an expansion screw 16. The mutual distance of the moulded body halves 13,14 set against each other can be :
adjusted by said expansion screw 16. On ~he sides of the plastic-made moulded body, clamping elements 17 of :~ bent steel wire are fastened while completely or parti- : ally surrounding the teeth 12.
. :
A wearing time measuring device 18 is attached within the orthodontic apparatus. The wearing time measuring device 18 i9 designed in integrated circuit technology and to~ether wikh the battery for power supply thereof i i8 cast into the moulded body half 14. Three ~lexible connecting: wires 19,20,21 are guided out of wearing time m~asuring device 18, each of them being soldered : to one end 17' of the adjacent lateral clamping ele-ments 17 and together wi~h the ends of the. clamping 1 :

:.i : ~ :
. ~
::

8 ~ ~ 7 ~ ~ ~ ~

elements being cast into the moulded body half 14. Con~
nection of the connecting wires to the ends of the clamping elements 17 can also be effected by miniatur-ized pole clamps as commonly used in electronics. The clamping elements 17 form the three exposed and easily accessi~le connectors 22,23,24 of the wearing time measuring device. 30th the wearing time measuring de-vice and its connecting wires 19,20,21 are completely cast into the moulded body half 14, and also the con-nectors between the wires and the clamping elements are ca~t along with them, so that the orthodontic apparatus comprising the wearing time measuring device is no dif-ferent in outward appearance from an apparatus with no wearing time measuring device.

The wearing time measuring device 18 comprises a pulse generator whose pulses are counted by a counter. Fur-ther, the wearing time measuring device comprises a temperature sensor and a moisture detector. The pulse generator is operated only when the measured tempera-ture is within predetermined limits and the moisture sensor detects a specific moisture. Thus, the counting of time is carried out only as long as the orthodontic apparatus is retained in the mouth of the patient. The number of counted pulses is interrogated by an external evaluation means which calculates the wearing time from the number of pulses and indicates the wearing time.

Fig. 2 shows a block diagram of the output stage of the wearing time measuring device 1 a with the three con-necting wixes 19~20,21 which are connected to the clamping elements 17 forming the three connectors 22,23,24 o~ the wearing time measuring device. For in-terrogation of the wearing time, the first connector 22 and the third connector 24 having ground potential ap-.
r - . ' , ' ' . , ~ , : ' :: : : `

: ` . .. ' : ,: , . . .' . : : : .

9 2 ~

plied thereto are connected to the external evaluation means so that the wearing time measuring device and the evaluation means can communicate with each other. The second connecting wire 20 connected to connector 23 is a measuring conduit. The measuring conduit is connected to moisture detector 25 which will start the pulse gen-erator of the wearing time measuring device - not shown in Fig. 2 - only when the connectors of the sec-ond and third connecting lines 20,21 are connected to each other by the moisture in the mouth.

The output stage further comprises an output control unit 26 for receiving, through an internal data line 27, the output signals of the wearing time mea~uring device to be transmitted to the evaluation means. The output control unit 26 includes a circuit means 28 hav-ing a control input 29 coupled to the drain D of a first MOSFET transistor 30. The signal output 31 of circuit means 28 is connected to the gate G of a second MOSFET transistor 32 having its drain D coupled to the first connecting line 19 via a resistor 33. Also gate D
of first ~OSFET transistor 30 is connected to the first connecting line l9. By the interposed MOSFET transis-tors, the input and the output resistances, respective-I ly, of the ,control input or the signal output of thecircuit means becomes highly resistive so that even in case of a short circuit between connectors 22 and 24 , the short-circuit current ~low will be low.
:' :
,I Th~ interrogation of the wearins time will be explained hereunder. ~he bidirectional data line 39 of the ex-ternal evaluation means 34 is connected by means of ; alligator clips 35 to the connectors 22,24, i.e. the wire clamps for attachment to the teeth, of the ortho-, dontic apparatus. At this point o~ time, the circuit :

., : ~

.

lo -- 2074~ ~4 means will still interrupt the outputting of signals to the first connecting line 19. Now, after the button 36 has been pushed, the evaluation means emits an inter-rogation signal which renders the first MOSFET transis-tor 30 conductlve. The signal is detected by circuit means 28, which then will feed to the first connecting line 19 the data to be transmitted. Evaluation means 34 receives the output signals of wearing time measuring device 18 applied to connectors 22,24 and on this basis calculates the wearing time which is indicated on a numeric display 37. Subsequently, by actuation of the push button 38, the counted value of the wearing time measuring device can be reset.

Fig. 3 shows a further embodiment of a removable ortho-dontic apparatus 11. This orthodontic apparatus 11 com-prises a lower and an upper arcuate wire 42,43 and is not provided with a molded plastic body as tbe appara-tus discribed with reference to Fig. 1. The arcuate wires 42,43 are detachably connected, by means of plug connections, to two clamps 44,44' fixedly attached to the rear molars 45,45'. The wearing time measurîng de-vice 18 is connected to the lower arcuate wire 42 by a sealing compound 46 which completely encloses the wear-ng time measuring device 18 and its connecting wires 19,~20,21. In this embodiment, the clamping or fastening elements of the wire structure can serve only as one of the connectors because all of the metal wires o~ the metal stxucture are electrically interconnected. To the lower arcuate wire 42 of the wire structure, there i9 connected the connecting wire 21 having the ground i .....
potential applied thereto, so that the wire structure ~j ~ forms the connector 24. The two other con~iectors 22,23 ~j consist of two pins 47,48 arranged side by side to each ¦ other, their ends being also cast into the sealing com-i I , .,,. ~ : :

~ .. . . ~ . ~ ,. . . . . . .. .. .. . . . . .. .

~ 2 ~ 7 ~ o ri ~

pound 46 and being electrically connected to the two conneeting wires 19,20 of the wearing time measuring device. By the sealing compound 46, the connectors are insulated from the electrically conductive wire struc-ture. The connectors are arranged in such a manner that they create no disturbing effect in the mouth and do not provoke the danger of injuries.

Also Fig. 4 shows an orthodontic apparatus having a wire structure without a moulded body, comprising an outer arc 58 closed by a band behind the head of the patient, and an inner arc y,y' joined to outer arc 58.
The complete structure is also called a head gear. For application of the head gear, the inner arc y,y~ is guided into the mouth of the patient and, by a respec-tive plug connection x or x', is connected on each slde o~ the jaw to the teeth 45 or 45' having bands attached therearound. During the intervals when application of the head ~ear is interrupted, the inner arc is pulled out of the plug connections and of the patient's mouth.
By means of this device, the band-holding teeth 45 and 45' are subjected to specific pressure forces which ultimately will move these teeth to the rear. The wear-ing time~measuring device 18 together with the connect-iIlg wires 19,20,21 is cast into a sealing compound 46 attached to the end of the inner arc y. The connectors 22,23,24 of the wearing time measuring de~ice 18 con-sist of three pins 47,48,49 arranged in a row, having their ends electrically conneeted to the three ~lexible connecting wires 19,20,21 and being also cast into the sealing compound 46.

In Fig. 5, there is shown a removable dental prosthetic apparatus 50. The apparatus comprises a substantially U-shaped bent moulded body 51 of plastic material with ! ~ :

' ~. ': . ' ', . ~ ' ' ' ' ' '~' ' ' " ''''' ''," '' ' '' '~ ', '.' " ' ', ' ' ~ '' .'' 2 0 7 ~

a plurality of false teeth 52 inserted therein. The plastic-made moulded body 51 has three fastening ele-ments 53 gripping around the teeth of the patient, con-sisting of bent steel wire and being fastened to the moulded plastic body 51. The wearing time measuring device 18 is inserted within the moulded plastic body on the inner side in the region of the molars and is sealded against moisture by a sealing compound. The three connecting wires 19,20,21 of the wearing time measuring device 18 are guided to the metallic fasten-ing elements 53 of the dental prosthetic apparatus and are soIdered thereto. The physician in charge can easi-ly connect the external evaluation means to the two fastening elements of the apparatus coupled to the data output of the wearing time measuring device. For avoid-ing confusionj the fastening elements wh~re the output signals can be picked up are marked by colored dots 54,54' to which there can be assigned connecting lines of the evaluation means likewise marked by colors.
Other than in the partial lower-jaw prosthesis illus-trated~in Fig. 5, wherein freely ending holding clamps are shown in the plastic-made main body 51, there exists also a~ variant wherein the main body with the holding clamps consists of one cast metallic body. This type of prosthesis is called a model cast prosthesis.
Onto this ba~ic structure, the dental technician will mount - by use o~ plastic - the plastic teeth designed for replacement. As described in connection with Fig.
3, the whole ba9ic structure will then form the ground :
~ ~ polej and the two other poles have to be arranged as ; auxiliary poles and, being insulated along with the wearing time measuring device 18 against the basic structure by means of plastic, have to be embedded into the~ov0rall pro6thesis. The wearing time measuring de-~; vice 18 can be arranged in ~he region o~ the molars as described with reference to~Fig.~ S.

~' ~
: I :

- 13 - 2~7~7'~

Fig. 6 shows a complete upper-jaw prosthesis 55 com-prising no ~astening elements provided as wire brack~
ets. This dental prosthetic apparatus comprises a plastic-made moulded body 56 adapted to the mouth of the patient and having the artificial teeth 57 inserted therein. The wearing time measuring de~ice 18 is cast into the moulded body 56 in the region of the molars.
On the opposite side, the connectors 19,20,21 provided as metallic pins 47,A8,49 are also cast into the mould-ed body 56 and are electrically connected to the wear-ing time measuring device 18 through the connecting wires 19,20,21 extending in the moulded body.

` ' :
.~
;:
:.

.~, , : :
, : :
`~1 . ~ , .

' :

, : ., . , ~ . .;. .: ~ ~ ' , .

Claims

1. A removable orthodontic apparatus comprising a holding means to be fastened within the mouth and an encapsulated electronic wearing time measuring device (18) having at least two connectors (22,24) connectible to an external evaluation means (34), c h a r a c t e r i z e d i n that the connectors (22/24) are freely exposed to the mouth cavity and that the signal output of the wearing time measuring device is short-circuit-proof.

2. The removable orthodontic apparatus according to claim 1, characterized in that the wearing time measuring device (18) comprises an output control unit (26) including a control input, for interrupt-ing the outputting of output signals to the signal output during the wearing time and for applying the output signals to the signal output after receiving an interrogation signal.

3. The removable orthodontic apparatus according to claim 2, characterized in that the output control unit (26) receives an interrogation signal of the external evaluation means (34) applied to the con-nectors (22,24).

4. The removable orthodontic apparatus according to claim 2 or 3, characterized in that the signal out-put and the control input are provided on the same connectors (22,24).

5. The removable orthodontic apparatus according to any one of claims 2-4, characterized in that the signal output and the control input are highly re-sistive.

6. The removable orthodontic apparatus according to any one of claims 1-5, characterized in that the holding means comprises at least one metallic fast-ening element (53) forming one of the connectors (22,24).

7. The removable orthodontic apparatus according to any one of claims 1-6, characterized in that there are provided at least two connectors (22,24) mount-ed on an insulating moulded body (56).

8. The removable orthodontic apparatus according to any one of claims 1-7, characterized in that a moulded body (13,14) to be placed in the mouth for adjustment of teeth is provided to have a plurality of clamping elements (17) electrically insulated from each other and to enclose the wearing time measuring device (18), and that the clamping ele-ments (17) comprise the connectors (22,24).

9. The removable orthodontic apparatus according to any one of claims 1-8, characterized in that there axe provided three connectors (22,23,24) whereof the first connector (22) is connected to the signal output and the control input, and the second con-nector (23) is connected to a moisture sensor (25) integrated into the wearing time measuring device, said moisture sensor (25) activating the wearing time measuring device (18) only in case of a cur-rent flow, caused by moisture, between the second and the third connectors (23,24), with the third connector (24) having a reference potential applied thereto.

10. The removable orthodontic apparatus according to any one of claims 1-9, characterized in that the connectors (22,23,24) are marked.