|Title of Invention||
A DENTURE BASE HAVING A PLURALITY OF DENTURES AND A METHOD OF PREPARING DENTURE BASES
|Abstract||A denture base on which an artificial replacement of teeth is implanted, characterized in that the denture base includes a plurality of dentures arranged and fixed in a plastic or metal foundation* wherein the dentures are arranged along with the occlusion curve expressed based on the central point set up on the resultant line showing the radius qfcurvature R of the optimal row of teeth obtained from the roentgenogram of a patient's temporal areas cf.che head, and the direction of the standard resultant of the pcwer produced at the time of occlusion.|
A DENTURE BASE, METHOD OF PREPARING DENTURE BASES, AND A DENTURE BASE COMPONENT
The present invention relates generally to a denture base, a method of preparing denture bases, and denture base components. More particularly, the present invention relates to a denture base used in creating dental diseases such as dentulous jaw and multr testh coloboma, a method of preparing- such denture bases, and denture base components immediately used in making denture bs-.ses. Hack ground AIM:
In treating- denture base and implanting dentures to care edentulous jaw. multi-teeth coloboma, etc., it is essential to give es.act occlusion in the treatment of dentures and brimed teeth.
In. order to give exact occlusion, the common practice is that dental doctors and denturists analyze the anatomical form and average value of hard tissue of each patient, and recognize his or her individual digestive movement ox lower-jawbone in the mouth with the help of virtual base lines and planes of the mouth and the circumference thereof. In practice, the dental doctors and denturists use those generally applicable data, and reconstruct patienna' occlusion on the individual basis,
The reconstruction of the occlusion of each patient mainly drperds upon the doctor's or denturist's individual skills. The
dependence cf practitioners' individual skills has made it difficult to quantitatively collect the data about occlusion ideal for sach patient set up & standard of what occlusal force and its strength are ideal for each patient. Because of lack of the standard applicable to patient by patient, it is time* and labor-consuming to make a denture base which can satisfy patients, such as those suffering from edentulous jaw.
Therefore, an object of the present invention is to provide a denture bass and a method of making same which enables the achievement of exact occlusion in a relatively short period of time with the Lsast toil by utilizing the resultant of actual occlusal forces.
SUMMARY OF THE INVENTION According to the present invention, the denture base includes a plurality of dentures arranged and £b*ed in a plastic or metal bed. wherei:;i. the dentures are arranged alon^ with the occlusion curve expressed based on the central point set up on the resultant line showing r;he radius of curvature R of the optimal row of teeth obtained from the X"ray of a patient's both temporal areas of the head, and the direction of the standard resultant of the power produced at the time of occlusion.
The standard resultant line is preferably a line connecting between a point set at the forward center of the parent's frontal siaus D.n the X ray and a lower jaw angle,
According to another aspect of the present invention, the method of making the above-mentioned denture base includes the steps of making a denture base foundation to a pattern taken from the patient's mouth patient by patient, and prepari.ng a denture
denture bases effecting ideal occlusion for each patient,
The present invention provides a method of preparing dentur* bases which includes the steps of representing a resultant line of the patient's occlusal forces on a roentgenogram taken from . tbo patient, setting a central point of a radius of curvature of the occlusion line on the resultant line, representing an occlusion curve on a occlusal model, the ccclusion curve having a radius equal to a distance between the central point and the occlusion line, and fixing dentures along the occlusion curve.
The resultant line is formed by a line connecting the front of ths patient's frontal sinus appearing or. the roentgenogram and the lower is.w angle, and the res ultanlf line is used to draw the occlusion curve.
The articulator according" to the present invention can be any type provided that it can three-dimensionally draw an occlusion curve ideal for patients on the occlusion model; basicalty; it includes a model support, and an arm capable of drawing a desired occlusion curve,, ths arm being three-dimensionally rotatable.
More specifically, the articulator of the present invention includes a base, a stand erected on the base, a lower jaw support attached to the base, a rotary member rotatably fixed to the stand, an upper jaw support provided at the front of the rotary member, a rod vertically inserted through the rotary member, a pendulunrlike &:;m whose length is adjustable, the arm being pivot ally supported on the upper end of the rod in a three-dimensionally rotatable manner, a projecting pawl fixed to a free end of the arm. thereby ensuring; that the pawl of the arm is brought into contact with a model of the upper jaw support and lower jaw support, and by
rotating the arm, the pawl three-dimensioaally draws an occlusion curve on a wax rim of the model, wherein the occlusion curve has a radius cf curvature equal to an effective length.
Preferably, each of the upper jaw support and the lower jaw . support ic- axially adjustable.
Preferably the face bow support capable of mounting* the face bev/ on the articulator at a predetermined position.
The articulator of claim 12 or 13, wherein the pair of arm and pawl comprise a plurality of pairs selectably fixed to the rods.
The face bow used in the present invention includes a base
provided near the patient's mouth, a pair of arms transversely
extending from the base, the tip ends of the arms being engaged
with the patient's ears, wherein the base is provided with a wax rim
support ;ixially adjustable.
An is evident from the foregoing description, the feature of
the present invention is in the achievement of an ideal occlusion
curve reproduced on the model obtained from each patient's
roentgenogram. In this way each patient can enjoy his or her ideal
denture bases which offer agreeable occlusion.
BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of an articulator according to the p':ese:::it invention;
Fig. 2 is a side view of the articulator shown in Fig-, l; Fig. 3 is a plan view of the articulator shown in Fig. l; Fig. 4 is a plan view of the articulator shown in Fig. l; Fig. 5 is a rear view of the articulator shown in Fig. U
Fig. 6 is a sketch showing a side of the skull of a patient;
Fig. 7 is a sketch two-dimensionally showing a resultant of occlusal i'orca in two dimensions!
Fig. 8 is a sketch exemplifying a resultant and an occlusion . curve of occlusal forces;
Fig*. 9 is a front view of the skull shown in Figs. 6 to 8 to show tho direction of an occlusal force;
Fig. 10 is a diagram three-dimensLonally showing a occlusal force act;i::ig at the time of occlusion;
Fig. 11(a) is a plan view showing a unit of arranged teeth;
Fig. 11(b) is a perspective view of the unit show in Fig. 11(a);
Fig. 12 is a plan view of a denture base;
Fig. 13 is a perspective view of a face bow;
Fig. 14 is a plan view showing a. main portion of the face bow shown in Fig, 13; and
Fig. 15 is a perspective view of the face bow in actual use.
DETAILED DESCRIPTION OF THE DRAWINGS Referring to Figs. 1 to 5. an articulator 1 embodying the present; invention includes a base 2, a stand 3 erected on the base 2, and a :fa-;:g bow support 5 on the opposite side of the stand 3. In this specification the 'axial' means the direction of the long axis of the articulable and the 'transverse' or 'crosswise' means che direction intersecting the axial direction at right angle.
A lower jaw support 4 is attached to the base 2 such that it is a:
The fac<:j bow support j.s integral with the face thereby ensuring a unitary movement in axial direction.> The support 3 includes a pair of side walls on the right and ief: of :lie axis of the articulator 1. A rotary member 7 is provided -in a spacs between the side walls of the support 3 in such a manner that it :.s rotated by an axle 10. As shown in Figs. 1 and 2, the rotary member 7 is rotated from its level state into a clockwise direetioa in Figs. 1 and 2 around the axle 10 and is fixsd at 45° and 90'. For this reason, it is convenient for attachment and detachment of the below-mentioned upper jaw model. Knobs 10a are fixed to the opposite ends of the axle 10, wherein the knobs 10a take a position corresponding to the patient's jaw'joint. The axle 3 is inserted in a slot 8 axiiilly extending, so that the axils 3 can slide axially.
Each of the knobs 10a can be provided with a member engageabLe with the ear of a face bow. Two bolts 11 are provided to limit the axial position of the axle 10, and bias the axle 10 under the action of a spring housed in the slot 8.
The rotary member 7 has its upper portion bent frontward, and a leg 7b in its lower part. The leg 7b is limited from its rearward movement by a shaft 15 whereby the rotary member 7 is restrained from its full rotation, thereby maintaining that the rotary member is maintained at a vertical angle as predetermined.
The shaft 15 is constantly biased rearward under the action of the spring housed in the slot 8. The rotary member 7 is loaded with an upper jaw model, and therefore., it is urged counterclockwise Fig, 1 but its rotatable movement is restrained by the axle 15.
A rod 25 is vertically inserted through the rotary member 7. The rod 25 has a double structure which consists of an outer sleeve
26 and. a middle sleeve 27 which is vertically adjustable and rotatable around the axis. The middle sleeve 27 is provided with an arm 30 in its upper section such that it is vertically rotatable around a pin 31. Reference numeral 23 designates a screw whereby the ■ outer sleeve 26 and the middle sleeve 27 ar-3 joined together.
The arm 30 is adjustable in length, having a pawl 35 at its free end, and the arm 35 can be attached to any arm 30 of different shape and size. It is preferred that arms 30 (with a pawl 35) of different lengths are prepared so as to select a suitable one depending- upon ths patient's age and body size.
The rotary member 7 is provided with an upper jaw support 40 at its frontward end, wherein reference numeral 45 designates a magnet made of iron piece whereby a jaw model is attracted thereon.
The articulator 1 operates as follows:
The feature of this articulator 1 is in the achievement of occlusion based upon a resultant occlusal forces. In other words, the tissue worked at occlusion consists of masculus masseter (Mm) ai.d masuculus temporlis (mt). The force produced by them is expressed in vector possessing direction and magnitude. It has been discovered that these resultants differ© with patients but as shown in Fig.;. 7 to 9, it is directed toward a point (N) in the neighborhood of the imnz edge of the frontal sinus (immediately above the nasion).
In Fig. 8 Pa is a point of occlusion of the front teeth, and Pb is a point o:: occlusion of the back teeth, and Pc is a point of arthrotome. T;ne occlusal force Nj, acting on the Pb of the back teeth, and the occlusal force >I2 acting on the Pc are in vector possessing the direction shown in Fig. 8, and the relationship between these occlusal forces and their resultant F is expressed by the following
.However, the resultants of all patients' occlusal forces do not concentrate toward the point 0 (Point N), but they differ with the conditions of aging bones. Generally; the resultant of occlusal forces gradually concentrates toward the point P on and along the line L (called "resultant line" or "vector axis") connecting the point N to the point P of lower jaw angle. This state is diagrammatically illustrated in Fig. 7. It will be understood from Fig. 7 that the "shoulii-be" point 0 (N) is displaced to the point 0' because of aging, thereby causing the radius of curvature D of the occlusal curve to change to D', and the arc C to change to C[f a circle is drawn centering about: a point on the resultant line L. whose position differs from patient to patient,, it will be supposed that the ideal occlusal points gather on tha line L. The point is relatively easily found from the row of the patient's remaining teeth and a roentgenogram. The present invention is based upon this discovery, and is to teach that the denture bases should, srart from the preparation of the arc, thereby ensuring an exact, ideal occlusion for patients.
Practically since each of the occlusal forces acts three-d:.mensionaily as shown in Fig. 9, the axes of teeth should comply with the direction of the occlusal forces.
Each occlusal force acts at the time of occlusion as shown in Fig. 10 in the following relationship:
where J;he arrow Z in Fig. 10 indicates the front. The subscripts R and L in. the equations indicate the right and the left The angle m;ide by the vector Nm and N1Lis expressed as 2 x l Among the two circles l\ and E2, the former is a circle containing two teeth and N point; 0, and the latter is a circle including a jaw joint and the pcinr. 0, & , and 9 2 each are projected angles. The line L representing the resultant F is a vertical line, and the line H representing the sum of its own, the line G indicating the sum of vector NtH and vector NlL and vector N^t and vector N2Il is in the vertical plane which all divides che skull into the right and left.
SLnce the length of the resultant line L measured from the roentgenogram of patient's temporal areas of head is two dimensional, it is desirable to rectify and use it as a three-dimensional length. This operation can be easily rectified using the angle fi from the length of the two-dimensional line L, and the
central Iinj> of a head as Fig. 9.
A practical process of making a denture base for a particular patient utilizing the above-mentioned principle will be described:
First, a side photograph (cephalcstandard photograph) of a patient? head is taken. Then, a foundation for the denture base is made ir_ a. known way; that is, the pattern of the patient's upper and lower gums is impressed on a tray filled with an impressing agent, and gypsum is poured onto the mold to obxain a piaster model. Abed of resin is made on the plaster model. Finally, an upper and lower alveolar rims (wax rims) is fabricated.
The wax rim is put into the patient's mouth, and the patient
is requested to bite so as to fix a central position of the upper and lower jaws. While the wax rims are bitten, the wax rims are joined to^ethi=r with wax. In this state, the affinity between the wax rims and the cheek mucosa and the outward appearance are checked and may b(: remedied.
The joined wax rims are brought into contact with the plaster model, and provisionally fixed together. It is mounted on the articulator 1 by use of the face bow 50.
As shown in Figs. 13 to 15, the face bow 50 includes a pair of arms 62 and 53 of resilient material, such as metal, extending rightward and leftward, wherein the branch portion, of the arms constitutes a base 53. Accordingly the arms 52, 53 and the base 53 are in one piece. Preferably, a plurality of metal bars are bent together. Alternatively, a metal plate having a width of a few Kiillime>:.*rs to a few tens of millimeters can be used. The base 53 is substantially U-shaped, and projects frontward. The base 53 is additionally provided with a wax rim provided in a patient's mouth.
Th.3 ar:xsi are provided with engagers 54 at each top end whereby the arms are fixed near the ear canals. The base 53 includes a slit 55 in which a wax rim support 60 is slidably fixed.
Ths? wax rim support 60 consists of a virtually circular metal" plate (alternatively, plastics or any other can be used), and a run on a fixed p.'u:t 81 designed to fix the wax rim thereto, This fixed part 61 consists of a rim of the rnetal plate which adhered to a recess of the wax rim support 60 at right angles. The rim is provided with a plurality of pinholes 62. Te wax rim support 60 includes a groove i 63 cut toward the center, and a nut 65 is welded near the port of the groove (53.
The nut 65 is provided with a bolt 66 having a knob 67 which is slidabte on the inside of the base 53. The bolt 66 is rotatable but cannot move in the axial Therefore, the turning of the knob 67 causes die wax rim support 60 to move for adjustment.
It is noted that the wax rim support 60 is not limited to the illustrated embodiment, and can be variously modified.
The face bow 50 is provided with an arch member 68 by means of a pivos 68a, so as to measure an angle between the two lines: namely, the line connecting the base 54 and the wax rim support 60 and the resultant line L. The arch member 68 is provided with an engager 69 to be fixed between the patient's eyebrows; (the root of his or her nose). When it is fixed, the apex of the arch, member 68 is exactly located on the point N.
The face bow 50 is operated as folicws*
First, the wax rim 100 is placed in the patient's mouth, and h? or isho is requested to bite it, so as to decide a central position of the u;:ip€-r and lower jaws. While the wax rims are bitten, they are
joined together with wax. In this state, the affinity between the wax rias and the cheek mucosa and the outward appearance are checked and may be remedied. In this way, the wax rims are fixed to the face bow 50. In order to fix them., the fixed portion of the wax rim-' suppor: 60 is pushed to the front of the wax rims in the patient's mouth, and pins are inserted into the pinholes 62 in the rims.
The joined wax rims are set in the articulator 1 by use of the face bow 50. Before the setting is done, the angle ro the vector axis (result i«nt line) of the face bow 50 is measured. As shown in Fig. 15, there is set a projected line L which connects the point N on the patient's head and the lov/er jaw angle (in the illustrated example, a projected line of the arch member 68). As the last step, the angle between the face bow 50 mounted on the patient and the line is measured (in the illustrated example, the angle a to the projected line L).
In this case, it is important that the angle (i.e. the angle in t]:,Q exact side view of a skull) taken at right angles to the sagittal plane of a skull (the halved sections of a skull) is measured. For this reason, i:: is desirable to measure the angle correctly by an instrument suitable for exposing a sagittal plane; for example, an instrument which can expose a sagittal plane using the point N positioned at the center of the patient's face and jaw joint near the ears. The sagittal plane obtained in this way can be effectively utilized i;o measure the angle accurately.
Referring to Fig. 2, the face bow 50 (the plaster model is omitted) set in the articulator 1 is provided with engagers 54 fixed to the jaw joints (the top ends 10a of the axis 10), and the height of the face bow support 5 is adjusted so as to cause the face bow 50 to face
the rod 25 at a predetermined angle (the previously measured angle a). Th=? jaw joint is ear the ears, so that it is easy to rebuild the set for individual patients.
The axis 10 is provided with holes adapted for insertion of the e:i-g:=:gers 54 of the face bow 50. In practice, the face bow 50 is feted by dint of the resiliency of the arm 52. If the resiliency is iiiiiufficent, and the fixture is found unstable, any device such as rubber bands, can be used to bias the arms toward each other. In the articulator 1 the resultant line or the vector axis is expressed by a vertical rod 25 thereby enabling the face bow 50 to stand at the angle a, where "he angle of the face bow is almost at right angle to the vector axis. As a result, when a plaster model loaded with wax rims i;? s-et in the articulator 1, the rims of the model is kept horizontal thereby facilitating' the subsequent operations. After the angle of the face bow 50 is adjusted, the plaster model is shifted to the articulator 1 with this adjusted an^le maintained, and fixed thereto. Then, the face bow is removed.
On the ether hand, the resultant line L which connects the point N (po:.nt that the resultant directs) and the point P of a lower jaw angle is written on the cephaiophctograph obtained beforehand; In this way a patient's occlusion curve (curve which passes along an occlusion point) is obtained, and the center 0 of the occlusion curve is set on the resultant line L. Then, the distance D (radius of the occlusion curve) between the center 0 and the patient's occlusion curve (the radius of the occlusion curve) is measured bv a
cuphaJophotograph. and the arms 30 and the pawl 35 are adjusted so that the measured D can be transferred to the model.
A curve is drawn by the pawl 35 of the tip end of the arm on
the; wax vims of the plaster model in which the upper and lower jaws
are unified into one piece. At this stage, the axle 25 supporting the
arm 30 is kept rotatable, thereby enabling the arm to rotate around
the axis 31. In this way, a three* dimensional arc can be drawn. The
axis 31 supporting the arm correspond? to the point N, and the
drawn arc represents the patient's occlusal curve. The
arm 30 can be fixed in a three-dimensionally rotatable manner by means of an adjustable coupler.
The skull of a patient differs from patient to patient. Taking this difference into consideration, it is necessary to adjust the length of the arm 30, the shape and size of the pawl 35 (a plurality of pawls can be prepared, and be replaced when necessary), the axial position arid vertical declining angle of the rotary member 7, the axial position of the lower jaw support 4, and the axial position of the upper jaw 40, so as to achieve occlusion ideal for each patient,
The upper and lower wax rims are vertically divided along the dxswn occlusion curve, and then a denture is implanted one by one along' the arch-shaped wax rim. More specifically, the dentures for the upper jaw are first placed on the wax rim for the lower jaw, and provisionally fixed. The wax rim for the upper jaw is cleansed with hoi water, and its resin base is exposed. The gap between the denture row and the resin base is temporarily kept as it is, and then, the up;?er jaw is removed from the articulator 1, and the gap is filled with resin so as to effect the integration of the denture rows.
The denture row of the lower jaw is fixed, but this fixture suculd be clone :.n agreement with the upper jaw. The procedure is the same as that described above about the upper jaw. Thus, a denture base incorporating the unified base and the denture row is
obtained. This denture base is finished into products, wherein it is polished if necessary.
In the embodiment described above, the arclrshaped curve for the denture row is based on the cephalophotograph of a patient's ' head. Alternatively, a mere simplified method is also possible;
The alternative method does not use a eephalophotograph, and a few dentures are provisionally fixed to the upper and lower alveolus nins transferred from the patients mouth, and the patient is requested to bite it to ascertain the optimum height and angle for the dentures. When an ideal occlusion is found, a regular occlusion curve iis obtained in accordance with the few dentures.
The procedure is the same as that of the case of the above-mentioned upper jaw almost. Thus, the denture base which the floor and th: denture sequence unified is obtained. Finish processing of polish ;,'equired for this denture base etc. is performed, and it is considered as a product.
In this way, based upon the jaw model taken from the patient's mouth, the foundation for the denture base to be fitted in his or her jaws is first fabricated. Then, a plurality of dentures suitable for the patient are implanted in place in his or her mouth, and a particular radius of curvature is determined by referring to the plurality of dentures. The radius of curvature obtained is utilized tc drs.w an arch-shaped curve on the rims, and unify the denture rows in one piece to obtain the expected denture base. The measurement and the determination of the arch-shaped curve can be effected by the arms and pawl of the articulator.
The manufacture of denture bases basically is time- and k.bor consuming, and requires a complicated procedure, because of
the fact that a lot of dentures must be fixed on the wax rims along tht; occlusal curve. According to the present invention, a simplified method will be provided:
A denture base component 70 set on the foundation along the ■ occlusion curve is prepared. Fig. 11 shows a denture row component 50 which is a member of the denture base component 70, having dentures T arranged and fixed on the rim P,
The occlusion curve used for the denture base component 70 diifers with the patient's age and physique, and the dentures have a variety of types. In order to enable patients to have a good choice of th3ir dentures, i~ is desired that more kinds of dentures should be stocked but two many kinds require a large warehouse, and the inventory increases, and the maintenance is costly. The optimum number of specimens is preferably a few tens; 30 to 50 kinds are ro commendable.
The patient can select one from the stocked denture base component as they like. The selected denture row component is sen or, the foundation 60 (indicated by the chain line in Fig, 11) fabricated in accordance with the model taken from the patient's mouth. In this case, a denture row selected from the prepared variety of kinds has a curve suitable for the patient's occlusion curve is set on a. curve passing through a point on the center of the arthrotome or a poins 2 to 3mm awav from it toward the external auditory meatus, and a line three-dimensionaily intersecting the tooth how face determined in the patient's mouth, and fixed on the foundation. The orocedure is as follows*
First, the model having the vertically halved wax rims is set in the articulator 1 along the occlusion curve, and the upper denture
row component 50 is set in agreement with the lower teeth.
Then., the upper wax rim gets rid of the wax, and the gap between the plasti: foundation and the denture row component 70 placed near the lower jaw is filled with high quality instantly * poLymeriaable resin except: for the upper plastic foundation 71 itself In this way, the unified plastic foundation and denture row as shown in Fig. 12 is obtained as the denture base 30.
As a major advantage of the present invention, the improved method of preparing a denture, base dispenses with the necessity of implanting dentures in the foundation GO fabricated in accordance with the shape of the patient's mouth. This is very economical and labor-saving;. The prepared denture rows are implanted along the curve drawn in accordance with the vector of the patient's occlusal force. The resulting denture base is ideal for the patient.
INDUSTRIAL APPLJCAB1TY As is evident from the foregoing- description, the present invention can efficiently make denture bases ideal ::or individual patients, In the foregoing description a denture base of plastics, but the material is not limited to it. The denture base can be made of metiu without any modification. The articulator of the present i:n.ven:ion. employs a three-dimensional!}' rotatahle arm, and the patients' occlusion curve taken from their roentgenogram can be reproduced on the model thereby simplifying the process of making denture bases.
1. A denture base having a plurality of dentures implanted in row on a foundation of plastics cr metal characterized in that the denture are arranged along the occlusion curve expressed in accordance with the radius of curvature R of an ideal denture row obtained lro.:n roentgenogram of the patient's temporal regions, and a center set on a resultant line of the patient's occlusal forces,
2. The denture base of claim 1, wherein the resultant; line is a line connecting a central point of the front of the frontal sinus in the roentgenogram and the lower jaw angle.
3. The denture base of claim 1 or 2, wherein the central point of the occlusion curve is disjplaceable toward the lower jaw angle with aae.
4. A denture fcase component used in making denture bases,
characterized in that it is set on a rim of foundation material having
denture rows along the occlusion curve drawn in accordance with a
curve of a radius of curvature R whose central point is displace able
toward the lower jaw angle with age, on the resultant line
representing the direction of resultant of occlusal forces.
5. A method of preparing denture bases., comprising the steps of
representing a resultant line of the patient's occlusal^ forces on a
roentgenogram taken from the patient, setting a central point of a
radiu=. of curvature of the occlusion line on the resultant line,
representing an occlusion curve on a occlusal model, the occlusion
curve having a radius equal to a distance between the central point
and the occlusion line, and fixing dentures along the occlusion curve. (3. The method of claim 5, wherein the resultant line is formed by a line connecting the front of the patient's frontal sinus appearing on the roentgenogram and the lower jaw angle, and the resultant line is used to d:raw the occlusion curve.
7. A method of preparing a denture base, comprising the steps of obtaining* a model taken from the patient's mouth, making a foundation for a denture base to be attached to the patient's mouth, preparing: a denture base component having the expected dentures fixed on rims made on the foundation, and fixing the denture base component on the foundation in accordance with a predetermined radius of curvature.
S. A mc-thod of preparing a denture base, comprising the steps of obtaining: a model taken from the patient's mouth, making a foundation for a denture base to be attached to the patient's mouth, obtaining a radius of curvature in accordance with the dentures by firung "he expected dentures on the patient's upper jaw rims, fixing a selected denture base component having the expected dentures in place in the patient's mouth in accordance with the size of an arch* shaped curve drawn with the radius of curvature. 9. The method of claims 7 or 8, wherein the denture base component comprises a denture row on a resultant line of the patient's occlusal forces, and arranged along an occlusion curve of radius of curvature R whose center is displaceable toward the lower jaw angle with age.
10. The method of claim 7 or 8, further comprising the steps of
preparing different types of denture base components, selecting one
ideal for the patient's occlusion curve, placing the selected denture
base component on a line three-dimensionally intersecting a tooth
bow surface characteristic of the patient's mouth, and fixing the
selected component on the foundation.
11. A method of preparing denture bases, comprising the steps of preparing; a base portion to be arranged in the patient's mouth, providing a pair of arms whose tip ends are engageable with points near his or her ears, preparing %* face bow by providing the base portion, with a wax rim support insertable into the patient's mouth, engaging' the pair of arms with around the patient's ears, arranging the base portion in the patient's mouth, fixing the wax rims to the wax rim support axially adjustable, drawing a projected line of the resultant on the patient's temporal areas, wherein the resultant line connects a central point of the front of the patient's frontal sinus and the lower jaw angle, obtaining the angle of the face bow to the projected line, fixing the face bow to the articulator, drawing an arch-shaped curve on the wax rims, wherein the arch-shaped curve has a point set on the resultant line as its central point to constitute the denture row along the arch-shaped curve,
12. An articulator comprising a support for an occlusion model, a:id an arm three"dimensionally rotatahie, the arm being capable of representing an occlusion curve on an upper jaw model and a lower js.w mod*! each supported on the support.
13. The articulator of claim 12, further comprising a base (2), a stand (3) erected on the base (2), a lower jaw support (4) attached to the base (2), a rotary member (7) rotatably fixed to the stand (3), an upper jaw support (40) provided at the front of the rotary member (7),' a rod (2o) vertically inserted through the rotary member (7), a pendulvun-like arm (30) whose length is adjustable, the arm being pivotally supported on the upper end of the rod (25) in a three-dimenisionally rotatable manner, a projecting pawl (35) fixed to a free end of the arm (30), thereby ensuring that the pawl (35) of the arm (30) is brought into contact with a model of the upper jaw support &nd lower jaw support, and by rotating the arm, the pawl three'dimensionally draws an occlusion curve on a wax rim of the model wherein the occlusion curve has a radius of curvature equal to an effective length.
11 The articulator of claim 12 or 13, wherein each of the upper jaw support and the lower jaw support is axially adjustable.
15. The articulator of claim 12 or 13.. further comprising a face
bow support (5) capable of .mounting the face bow on the articulator
at a predetermined position.
1(5. The articulator of claim 12 or 13, wherein the pair of arm and
pawl comprise a plurality of pairs selectively fixed to the rods.
17. A ::'ace bow comprising a base (.53) provided near the patient's
isouth, a pair of arms (52) transversely extending from the base (53),
the tip ends of the arms being engaged with the patient's ears,
wherein die base (53) is provided with a wax. rim support (60) axially
18. A denture base having a plurality of dentures implanted in a row on
a foundation of plastics or metal substantially as herein above
described with reference to the accompanying drawings.
19. A method of preparing denture bases substantially as herein above
described with reference to the accompanying drawings.
|Indian Patent Application Number||81/CHENP/2004|
|PG Journal Number||13/2009|
|Date of Filing||14-Jan-2004|
|Name of Patentee||NISHIHAMA, NAOKI|
|Applicant Address||1203, MINAMIGUCHI 2, 14-5, TAKARAZUKA, KYOGO,|
|PCT International Classification Number||A61C11/025|
|PCT International Application Number||PCT/JP02/07234|
|PCT International Filing date||2002-07-16|