Description

INTEGRATED DENTAL CARE APPARATUS

[0001] FIELD OF THE INVENTION

[0002] The present invention relates to an integrated dentalcare apparatus which comprises at least a patient chair and a dental care unitand to which is structurally connected at least one of the following: aspittoon arrangement comprising a water tap and possibly a cup stand, an armfor dentist's instruments, an arm for an assistant's instrument unit, an armconnected to a suction system of the integrated dental care apparatus, an armfor a display screen, an arm for an operation lamp, an arm for a tray, an armfor some other device or implement used in a dental care environment, aconnector structure for any device or implement used in a dental careenvironment, whether mentioned above or not.

[0003] BACKGROUND OF THE INVENTION

[0004] In prior art, dental care units have been implementedas different constructions for different cultures amongst dentists, among otherthings. The dental care unit in itself is an apparatus used in connection withdental work, one essential and traditional function of which is to properlysupply the dental instruments used by the dentist with the physical quantitiesrequired for their operation, such as operating power (e.g. electricity orpneumatic air) and/or water. In this context, and as evident to any personinvolved with dentistry, by the term dental care unit is thus meant a physicalentity having a cover enclosing means for such a supply function at least, lnconnection with dental work, it is often also necessary to use instruments forremoving blood, spit, tartar pieces etc. from the patient's mouth by suction. To allow the instruments to be kept at hand, the dental care unit is typicallyprovided with various holders and/or arms. The dental care unit may even haveseveral arms attached to it, for facilities such as an operating light andtoday e.g. a display screen. In some solutions, the patient chair is alsointegrated with the dental care unit to form a single apparatus. To be able toserve clients in regions differing in respect of the culture of dental care andalso to respond to dentists' individual needs and practices regarding e.g. theway in which the dentist wishes the instruments

to be available in connectionwith a dental care operation, manufacturers may have to keep numerous differentapparatus versions in production.

[0005] One solution to reduce the number of differentversions is to realize the apparatus as enabling realization of differentconfigurations in order that the same basic construction can be utilized tomeet at least two different client needs. As dental care units generallyrequire connections for e.g. pneumatic air, suction and drainage, and oftenalso for an incoming water network and electricity, such connections aretypically built in the treatment room as permanent fittings by providing therequired lines and connections in connection with this permanentinstallation.

[0006] A special category among dentists is the left-handeddentists. Particularly as dentists today typically work from one side of thepatient lowered to a lying position, it is typically more natural for aleft-handed dentist to work from a different side of the patient than theright-handed dentist prefers.

[0007] The prior art includes integrated dental careapparatuses implemented as allowing shifting even between the left/right-handedworking. There is e.g. a prior-art arrangement in which the patient chair isfixed to the floor and the lines required for the instruments and other devicesintended to be used via the dental care unit are passed thereto through thestructures of the patient chair, and in which the dental care unit is connectedto the chair by mounting it at an end of an arm part, which is arrangedturnable with respect to a vertical axis so that the dental care unit can beturned from a first side of the patient chair to its second side. Althoughthese arrangements do improve the situation in view of use of the apparatusfrom either side of the patient chair, yet the outcome of this solution as suchis not symmetry in view of all conceivable parts of the integrated dental careapparatus.

[0008] On the other hand, the construction as described abovecomprises a basic structure wherein the patient chair is mounted on the floor.ln many dentists' opinion, however, absolutely more ergonomic are integrateddental care apparatuses in which the patient chair is not fixed to the floorbut in which the chair raising mechanism is arranged e.g. in connection withthe dental care unit. A possibility provided by a basic structure like this isthat the

patient chair can be implemented as a relatively thin structure, making it possible to provide under the chair a space sufficient to allow thedentist to work in a sitting position even with his/her knees under the patientchair. Integration of patient chair and dental care unit provides a possibilityto reduce the number of components needed in the apparatus.

[0009] Further, in addition to the patient chair, the dentalcare unit or the apparatus formed thereof often being arranged in the dentaltreatment room as a permanent installation, the dental treatment space istypically also provided with other fixed structures, such as shelves or e.g. adental x-ray device mounted on a wall. Typically, the permanently installedsolutions do not provide much possibilities for e.g. changing the patient'sposition on the treatment chair relative to the fixed structures in thetreatment space, any more than for e.g. changing the dentist's or assistant'sworking location relative to these structures, or relative to other structuresthat may be comprised in the integrated dental care apparatus. Even morebroadly speaking, considering many integrated dental care apparatuses in whichseveral functionalities are integrated in the same construction, in many casesplacement of different parts of the apparatus and the possibilities ofadjusting their position leave room for improvement e.g. from the point of viewof ergonomic working and the special requirements imposed by variable practicespaces.

[0010] BRIEF DESCRIPTION OF THE INVENTION

[0011] The object of the current invention is to provide anew concept for an integrated dental care apparatus, a concept which in itselfand in its preferred embodiments enhances variability of the apparatus to meetdifferent needs of different dental treatment rooms, especially in a way thatpermits better attendance to dentists' individual needs. The aim is still toretain the basic construction known in itself, wherein the patient chair is notarranged to be mounted on the floor but wherein it is arranged to be supportedby other structures of an integrated dental care apparatus. A specificobjective is additionally to enable the construction to be implemented in amanner that allows the apparatus to be arranged to be symmetric, preferably inrespect of all its parts and properties visible to the

user, so that all partsof the apparatus can be positioned in the same way on either side of thepatient chair, and that the instruments and other devices connectable to it canbe used in the same way from either side of the patient chair.

[0012] BRIEF DESCRIPTION OF THE FIGURES

[0013] In the following, these and some other objectives ofthe invention and some of its preferred embodiments will be described ingreater detail by also referring to the attached drawings, wherein

[0014] Fig. 1 represents the basic structure of a preferredembodiment of the apparatus of the invention in side view,

[0015] Fig. 2 represents the basic structure of a second preferred embodiment of the apparatus of the invention in side view,

[0016] Fig. 3 represents a third embodiment of the apparatusof the invention in side view,

[0017] Fig. 4 shows some possible positions of the patientchair relative to the dental care unit,

[0018] Fig. 5 shows some possible positions of the dentalcare unit relative to the patient chair,

[0019] Figs. 6 and 7 present in side view one preferredembodiment of the apparatus of the invention,

[0020] Fig. 8 represents the apparatus of the invention asseen from above, positioned for right-handed work on the one hand and forleft-handed work on the other hand, and

[0021] Fig. 9 illustrates one possible way of positioningthe components of the apparatus according to Fig. 6 in the working space.

[0022] DETAILED DESCRIPTION OF THE INVENTION

[0023] Fig. 1 presents in side view a basic structure of theintegrated dental care apparatus 1 according to the invention. The apparatusaccording to Fig. 1 comprises a floor-mounted dental care unit 10 and a patientchair 20 arranged to be supported by a substantially horizontally extending armpart 21 connected to the dental care unit 10. In the solution according to Fig.1 , the dental care unit 10 including a vertically extending part is likewisearranged to be supported by a substantially horizontally extending

arm part 11 , the base end of which being arranged in connection with the floor-mountstructure of the dental care unit 10. According to the invention, both thepatient chair 20 and the dental care unit 10 are arranged to be turnablerelative to a vertical axis 101 , 102. The dental care unit 10 may be arrangedto be turnable through 360 degrees relative to the vertical axis 101 , 102. lnthe solution illustrated in Fig. 1 , the dental care unit 10 turns substantiallyalong with its arm part 11 while the arm part turns substantially about amounting point located at its base, whereas the patient chair 20 rotatessubstantially at the end of its supporting arm 21. As this constructionincludes the floor mounted substantially horizontally extending arm part 21 which supports the dental care unit 10, the bottom of the vertical part of thedental care unit 10 stands at a distance from the floor level. In theconstruction of Fig. 1 , the dental care unit 10 may be provided with means forraising and lowering the arm part 21 supporting the patient chair 20. However,support of the patient chair 20 and adjustment of its vertical position canalso be implemented in other ways, e.g. by using a lever-arm type structure. Preferably at least part of the mechanics required for changing the heightposition of the patient chair 20 is arranged in connection with the dental careunit 10, though. In Fig. 1 , the axes of rotation 101 , 102 of thepatient chair 20 and the dental care unit 10 are represented by a unified lineto emphasize that in this embodiment of the invention, positions of saidvertical axes 101 , 102 unite. However, the construction according to theinvention can also be implemented in such a manner that the vertical axis 101 relative to which the dental care unit 10, or as according to Fig. 1 that ofthe supporting arm 11 of the dental care unit 10, is arranged to be turnableand, on the other hand, the vertical axis 102 relative to which the patientchair 11 is arranged to be turnable, lie at a distance from each other (Fig.2). Such an arrangement allows the position of the patient chair 20 to bechanged in the dental treatment space even though the integrated dental careapparatus 1 itself is floor-mounted. This solution brings on certain additionalfeatures, out of which e.g. the one could be mentioned here that a shift in themutual position of the parts of the construction from a left-handed person'sworking

arrangement into a right-handed one and vice versa can be realized in asmaller space than what is possible as compared to the construction accordingto Fig. 1.

[0025] The rotation of the patient chair 20 relative to thedental care unit 10 can be implemented by a motorized technique. According to apreferred embodiment of the invention, the apparatus is provided with anarrangement enabling these two parts to be turned independently of each otherj.e. e.g. so that one of them is stationary while the other is moving. On theother hand, it is possible to provide e.g. the control system of the apparatusand its user interface with various automated functions for bringing the partsof the apparatus into given desired positions relative to each other, lnaddition to the parts already discussed, the above may also be arranged toapply to other parts that may be included in the apparatus. According to onepreferable embodiment, the means for enabling the dental care unit 10 to beturned relative to a vertical axis 101 , 102 are arranged substantially inconnection with the means for mounting the dental care unit 10 on the floor. Onthe other hand, the means for enabling the patient chair 20 to be turnedrelative to a vertical axis 101 , 102 may be arranged in connection with themeans 21 for supporting the patient chair 20.

[0026] According to one embodiment of the invention, theactual dental care unit 10 is not arranged to be turnable at the end of asupporting arm 11 at a distance from the vertical axis 101 as in Figs. 1 and 2but is instead arranged to be turnable substantially in place, i.e. e.g. insuch manner that the dental care unit 10 includes no substantially horizontallyextending arm part 11 as described above at all but the aforesaid physical orvirtual vertical axis 101 passes through the actual dental care unit 10 itself(Fig. 3). On the other hand, besides that the patient chair 20 may be arrangedturnable substantially about itself, it may also or alternatively be arrangedturnable as supported by its supporting arm 21 , along with the rotating motionof the supporting arm 21.

[0027] In Fig. 1 , the patient chair 20 is shown in aposition where the backrest 24, which is functionally connected to the actualseat part 23 of the chair, has been raised to an upright position. According toone preferred embodiment

of the invention, the dental care unit 10 is arrangedto be turnable relative to the vertical axis 101 in such manner that, when thedental care unit 10 is being turned, it simultaneously moves along a circularpath of a radius just barely sufficient to allow the dental care unit 10 to beturned to the other side of the patient chair 20 while the backrest 24, andwith it the headrest 25 of the patient chair 20 are in an upright position (orin other words, to allow the patient chair 20 to be turned the other way roundrelative to the dental care unit 10). Turning of the patient chair 20 may bearranged through a part attached to the seat part 23 arranged to be turnablerelative to a horizontal axis 101 , 102.

[0028] According to the invention, the dental care unit 10can in principle be arranged to turn around the patient chair 20 by the side ofthe footrest 22 of the chair 20 as well, e.g. by arranging the footrest 22 tobe turnable into a vertical position. However, the first-mentioned alternativeenables a functionality wherein the patient is in a sitting position forconsultation (Fig. 1) while the dental care unit 10 is out of sight behind thebackrest 24 and, after the consultation, the dental care unit 10 and thepatient chair 20 are moved into a desired relative position for treatment. Fig.4 presents a top-view illustration of the relative location of the patientchair 20 and the dental care unit 10 in a consultation situation (solid lines), and placements of the patient chair 20 relative to the dental care unit 10 intoright- and left-handed working positions (broken lines). To simplify thefigure, the supporting arm 21 supporting the patient chair 20 is not shown inFig. 4 - and, its position being obvious to a skilled person, neither is itshown in the subsequent figures representing the apparatus in top view.

[0029] Fig. 5 presents the relative positions of the patientchair 20 and the dental care unit 10 corresponding to Fig. 4, but from thepoint of view of how the position of the dental care unit 10 changes inrelation to the patient chair 20 upon a change from the consultation positioninto right- and left-handed working positions.

[0030] In the above description, the dental care unit 10 andthe patient chair 20 comprised in the integrated dental care apparatus havebeen considered, but besides a work post for the dentist, many modernintegrated dental care

apparatuses additionally comprise a work post for anassistant, which is typically located on the other side of the patient chair 20relative to the dentist's work post - i.e. typically on that side of thepatient chair 20 where the dental care unit 10 is located. In practice, theassistant's work post may consist of e.g. an instrument stand or unit separatefrom the dentist's instrument table and attached to the dental care unit e.g. via a hinged arm structure. The assistant's instrument stand or unit istypically arranged to be secured to an arm system allowing the instruments tobe reached from the assistant's work post as well as from the dentist's workpost - either by enabling the instrument stand or unit to be turned to theother side of the patient chair 20 by passing it under the patient chair 20, orby enabling reaching the stand over the patient chair 20. For example, thesuction system of a dental care unit is often arranged at the assistant's workpost.

[0031] The arrangements presented in Figs. 6 and 7 includeone embodiment applicable in the invention for another instrument holder 62 tobe provided in the integrated dental care apparatus 1. This solution comprisesan articulated arm system 60 arranged to extend from the dental care unit 10, connected to the dental care unit 10 at its bottom, to support an assistant'sunit 61. The assistant's unit 61 is arranged to be turnable relative to atleast two vertical axes 160, 161 located at a distance from each other.

[0032] Thus, according to one preferred embodiment of theinvention, the instrument holder 62 forming an essential part of theassistant's work post is also arranged in connection with the dental care unitiO in such manner that, when right-handed placement of the parts of theintegrated dental care apparatus is changed to left-handed placement, theassistant's unit 61 including the instrument holder 62 can be turned into acorresponding position relative to the dental care unit 10 and the patientchair 20. According to a preferred embodiment, this is implemented firstly byusing an arrangement where the assistant's unit 61 is mounted on an arm 60extending substantially vertically to the dental care unit 10 from below thedental care unit 10, said arm 60 being turnable at its base relative to avertical axis 160, so that the assistant's unit 61 , too, is mounted on this arm60 to allow the assistant's unit 61 to be turned in relation to a

secondvertical axis 161. Further, if the assistant's unit 61 is provided with anadjustably placeable instrument holder 62, then the position of the latter alsohas to be arranged to permit the holder 62 to be symmetrically placed relativeto the assistant's unit 61. In addition to the right-left-handed property, suchan arrangement also provides versatile possibilities for positioning theinstrument holder 62 in connection with the assistant's work post itself. InFigs. 6 and 7, the assistant's unit 61 comprises of a vertical member, which isarranged in the arm 60 and which carries the instrument holder 62 for theassistant's instruments. This type of vertical member of the assistant's unit61 is often arranged to form a part of the suction system of the integrateddental care apparatus. The vertical member of the assistant's unit 61 may bearranged to be turnable through 360 degrees relative to a vertical axis161.

[0033] To enable the dentist's work post to be madeidentical on either side of the patient chair 20, it is necessary to consider,besides the patient chair 20 and the dental care unit 10, also other parts thatmay be included in the integrated dental care apparatus. For example, typicallya spittoon arrangement 12 with a water tap and a cup stand is arranged inconnection with the dental care unit 10 (Fig. 4). In a preferred embodiment ofthe invention, the spittoon arrangement 12 is also implemented in such mannerthat all its parts locate themselves or may be located in a correspondingmanner from the user's point of view regardless of whether the dental care unitiO is reviewed from the point of view of right-handed or left-handed work. Forexample, if location of the spittoon 12 is arranged to be variable, it may bearranged to be turnable symmetrically relative to the dental care unit 10, toeither side of it.

[0034] Further, a modern integrated dental care apparatustypically also comprises at least one, often at least two arm structures 40, 50attached to the dental care unit 10 to accommodate auxiliary equipment, such asan operating light 51 and e.g. instruments to be positioned on the instrumenttable 41 for use in dental work (Fig. 6). For example, in view of aconsultation position of the apparatus, it is possible to provide the apparatuswith an arm for a (computer) display screen.

[0035] Arms like those described above are typicallyattached to a column 30 extending vertically from the dental care unit 10. Onthe other hand, as not shown in the attached figures, especially an armcarrying an instrument table can also be arranged to be attached to thepedestal of the dental care unit 10, either to its immovable part fixed lymounted on the floor or to the part above it, i.e. to the part of the dentalcare unit 10 located under the patient chair 20 and turnable in relation to theaforesaid vertical axis 101.

[0036] According to one preferred embodiment of theinvention, this kind of arm systems, especially the arm system 40 forinstruments, are so implemented that the arm system can be positionedsymmetrically relative to the patient chair 20 irrespective of on which side ofthe patient chair 20 the dental care unit 10 is located. For example, in theembodiment presented in Fig. 7, this has been realized by providing threeswivel joints 401 , 402, 403 in the instrument arm 40. Of these swivel joints,the first 401 enables the instrument arm 40 to be turned in a horizontal planeat its base, the second 402 bending of the arm in a horizontal plane and thethird 403 turning of the instrument table 41 , arranged at the end of the arm40, in a horizontal plane. The height position of the instrument table 41 onthe column 30 can be arranged to be adjustable, and likewise the instrument arm40 can be provided with a joint (not shown in the figure) permitting adjustmentof the height position of the instrument table 41.

[0037] The instrument table 41 or equivalent of theintegrated dental care apparatus is typically arranged to hold severaldifferent instruments requiring different operating quantities. To allowinstruments to be placed in a desired order on the instrument table 41 , asolution known as such is to arrange at least some of the instrument places tobe universal. According to one preferred embodiment of the invention, in orderto enable the typical dental instruments to be arranged in a correspondingorder irrespective of whether the instrument table 41 is positioned for right-or left-handed use, all the instrument places are arranged to be universal.

[0038] Correspondingly to what was said above regarding theinstrument places of the instrument table 41 , the assistant's work postjncluding the instrument holder 62 and instrument places used therein, islikewise

preferably implemented so as to allow at least some of the instrumentsto be placed in the same way from the point of view of the user of theapparatus in both right-handed and left-handed situations.

[0039] Thus, according to a preferred embodiment of theinvention, at least all those parts of the integrated dental care apparatuswhich are visible to the dentist and/or dental assistant are arranged to bepositioned and used in such manner that the treatment work post can be arrangedto be symmetrically identical on either side of the patient chair 20. One wayof describing the invention is thus to define it as comprising an integrateddental care apparatus in which a patient chair 20 and a dental care unit 10 arearranged to be substantially symmetrical and the patient chair 20 is arrangedto be turnable relative to the dental care unit 10 about an axis 101 , 102arranged in the plane of symmetry of the dental care unit 10, and in which preferably also the other parts of the apparatus, such as the structuressupporting the dentist's and assistant's instruments, the operating light etc., are arranged to be turnable relative to an axis arranged in the plane ofsymmetry of the dental care unit 10.

[0040] The integrated dental care apparatus of the inventioncan also be described as comprising a patient chair 20 and a dental care unitiO, in which apparatus at least one of the following is structurally connectedto the dental care unit: a spittoon arrangement 12, an arm 40 for dentist'sinstruments, an arm 60 for assistant's instruments and/or for a suctions systemof the integrated dental care apparatus, an arm for a display screen, an arm 50for a light 51 , an arm arranged for some other device used in a dental careenvironment, a connector structure for any device used in a dental careenvironment, whether mentioned above or not, and in which the integrated dentalcare apparatus is arranged to comprise means for mounting it on a floor and thedental care unit 10 and patient chair 20 are structurally connected by meanssupporting the patient chair 20 at least. Further, the apparatus may beimplemented by arranging said dental care unit 10 to be symmetrical at least asfar as the external parts visible to the dental treatment site are concerned,to form at least one vertical plane of symmetry, with which plane of symmetrybeing arranged to

unite at least the axis 101 , 102 relative to which the arm40, 60 for assistant's instruments and/or dentist's instruments is arranged tobe turnable, and further said patient chair 20 being arranged to be symmetricalat least as far as its external parts are concerned to form at least onevertical plane of symmetry, with which plane of symmetry the axis 101 , 102relative to which said dental care unit 10 has been arranged to be turnable isarranged to unite.

[0041] Further, the apparatus of the invention may comprisean assistant's unit 61 arranged to comprise at least one plane of symmetry atleast in respect of its external parts, which unit 61 is located in connectionwith the aforesaid arm 60 for assistant's instruments and comprises at leastone instrument holder 62 provided for said assistant's instruments, theposition of said instrument holder 62 being arranged to be adjustable relativeto an axis 161 uniting with at least one of the aforesaid at least one plane ofsymmetry. The apparatus may also comprise one, two or more substantiallyhorizontally extending arm structures 40, 50, 60 which are arranged to supportinstruments or devices used in connection with dental care work and which arearranged to comprise at least one such articulated shaft which unite with theaforesaid plane of symmetry of the dental care unit 10. The dental care unit 10may also comprise a spittoon arrangement 12 which itself or at least some ofthe components comprised in it is/are arranged to be adjustable in position sothat it or they is/are turnable relative to an axis uniting with the aforesaidplane of symmetry of the dental care unit 10.

[0042] The invention and its various embodiments make itpossible, among other things, to implement a common dental practice for aright-handed and a left-handed dentist using the same integrated dental careapparatus. Further, in the case of possible resale of the apparatus orpractice, the invention makes it irrelevant to consider whether the previousand future users of the apparatus are of the same or different handedness. Themovements of the parts of the apparatus can be arranged to be motorized ormanual as desirable, e.g. according to how frequently each

re-positioning ofthe parts of the apparatus is likely to be done at the practice.

[0043] One preferred embodiment of the invention comprises apossibility to turn the patient chair 20 through 180 degrees (at least) withrespect to the dental care unit 10. When this is combined with that preferredembodiment of the invention wherein the vertical axes 101 , 102 relative towhich the patient chair 20 and the dental care unit 10 are arranged to beturnable lie at a distance from one other, the apparatus makes it possible toachieve versatile and completely new kinds of possibilities for placement ofparts of an integrated dental care apparatus in which the patient chair 20 andthe dental care unit 10 are integrated to a single assembly. For example, Fig.8 visualizes how the dental care unit 10 and the patient chair 20 can bearranged in turned positions with respect to each other, thus modifying thespace available at the assistant's work post. The patient can be positioned indifferent orientations in the treatment space and e.g. moved closer to a givenwall, cupboard or the like in the treatment space if necessary, in other words, brought to a closer or more ergonomic position in relation to e.g. awall-mounted dental X-ray apparatus or other piece of auxiliary equipment, suchas a light, microscope, monitor, camera, etc. The fact that the patient can bepositioned in relation to a piece of auxiliary equipment allows in principlethe arm systems for the auxiliary equipment to be implemented in a simpler formthan before. On the other hand, the apparatus of the invention provides morepossibilities regarding positioning of additional equipment in the treatmentspace because such equipment need not be so carefully located but the patientcan be brought to a position within reach of such equipment.

[0044] Regarding the invention and its preferredembodiments, it is further worth mentioning that, as the various objects andcupboards in the treatment room are typically located in predetermined places,the invention provides the possibility that, when the dentist is workingalone/with an assistant, the position of the patient chair 20 can be changedsomewhat so that when working alone the dentist is able to reach the cupboardson the assistant's side - whereas when an assistant is present, the assistantserves the

dentist from his/her own side and extends articles from that side tothe dentist.

[0045] Furthermore, the invention makes it possible tooptimize the assistant's working space by moving the dental care unit 10 as farfrom the assistant as possible and, on the other hand, to move it closer e.g.when the patient needs to reach to the spittoon 12. The dental care unit 10 canalso be brought closer to the patient chair 20 when the assistant leaves thework post to attend to other tasks, and thus the dentist is better able toreach e.g. to the spittoon 12, a cup and the instruments placed on theassistant's instrument holder 62.

[0046] An essential feature of the preferred embodiments ofthe invention is that the axes of rotation of rotatable parts of the apparatusare arranged in an appropriate manner in the plane of symmetry of at least oneother part of the apparatus, and it is possible to provide several separateplanes of symmetry in the apparatus.

[0047] The instrument table or holder used in the integrateddental care apparatus may comprise at least two such instrument connectionplaces, arranged especially in the corners of the instrument table, whereto aspray instrument can be placed symmetrically. The apparatus of the inventionmay also comprise symmetrically arranged connection places e.g. for a displayscreen or graphic user interface.

[0048] In one preferred embodiment, the horizontal dimensionof the means 21 for supporting the patient chair 20 is substantially of thesame order of magnitude as the horizontal dimension of the horizontallyextending part 11 of the support structure for the dental care unit 10. In suchcontext, a preferable distance between the vertical axes 101 , 102 relative towhich the patient chair 20 and the dental care unit 10 are arranged turnable isof the order of 200 mm or less.

[0049] Yet further embodiments of the invention are evidentto a man skilled in the art within the scope of the following claims.