US2570562A - Artificial denture - Google Patents

Description

Oct. 9, 1951 J. D. KINSLEY 7 2,570,562

ARTIFICIAL DENTURE Filed Feb. 24, 1948 FIG. 9

IN V EN TOR. J. D. K lNSLE Y ATTORNEY Patented Oct. 9, 19 51 2,570,562 i R IFI'cI L man-Tm... Jason D. Kinsley, Cedar RapidaIoWa" 1 Application February 24, 1948. serial No. r0394 present invention relates to artificial human teeth and more particularly to the occjlusa'l surface thereof and the method by which such surface is produced. The principal objective of my invention is to produce a set of bicuspid and molar teeth which are adapted to form a balanced occlusion. This is established by intraorally milling a set of abrasive bite rims to, a perfectly balanced occlusion to serve as a pattern fo'rjJthe occlusal contour of the teeth, whereby to .producea proper relation between the'mandibular and maxillary teeth.

In order to produce a perfectly balanced clusion throughout the entire range of the mandibular function, it is necessary that certain requirements be met. I have found that, by the porting gum ridges during intraoral milling procedure. This is produced by a rotation. of the right condyle within the glennoid fossa and asimultaneous downward and forward move-, ment of the left condyle in its. path but, when the mandible moves leftward from the centric position, the action is reversed and thereis rotation of the left condyle in-the glennoidflfossa and a simultaneous downward and forward movement of the right condyle in its path, thus shifting the direction of movement. As this shifting takes place, a rocking or tiltingof the base platesupon the supporting gum ridges. is caused. To overcome this difficulty, I first mill the protrusive curvature and then cut anarrow groove in the upper rim on both the right and left sides along the lines of the lingual bicuspid and molar cusp area. I then fill these grooves with a hard abrasive cement which will not become distorted upon lateral milling. I then carve away'the lateral borders from thecement, leaving it in the form of a prominent crest. The case is then placed in the patients mouth and he is asked to move his jaw laterally toward the right and left. This causes milling in of the lateral concavity and inclination 'on the lower bite rim. The right and left movements 'from centric position are separate and independent. By these actions, the left lingual and right buccal slopes are simultaneously milled upon the leftward movement of the mandible, while, upon rightward movement, the right lingual and left buccal are milled. By the (opera;

1 Claim. (-01. 32-3) movements of the mandible. The case is then keyed inrcentric and mountedupon an articue lator, the cement crest removed from the upper rim and replaced .with alayer of heatsoftened tions described, a perfectly-balanced occlusion is a established, both as to protrusion and lateral modeling compound and, with the lower rim cold and wet, the articulator is then closed, thus forming a counterpart of the'lower milled occlusal surface in the compound on the upper rim. The lower. teeth are then set to correlate with the described counterpart and then the upper teeth are set to articulate with the lower teeth, the teeth being made to simulate the occlusal surfaces ofthe milled bite rims. i

In the drawings annexed hereto and forming a part hereof, j r

Fig. 1 shows a cross-section of both upper and lowerdentures in centric relation;

' Fig. Zshows a mandible moved to one side and insuch contact with the upper teeth that thereis no rocking of the denture on a gumridge; Fig. 3 showsfthe formation of a concavity in the occlusal surface of the lower bite rim during the milling in process; v v v I Fig. 4 shows a variationin inclination of the surfaces of occlusion, which variation occurs in some mouths, and in'varying degrees, and shows,

also, on "the right side, the'fis sures in thelower occlusal surface as being arranged transversely to'the'movement of the mandible;

Fig. 5 shows the form ofjan occlusal surface of a set of bicuspid and molar upperteeth;

Fig. 6 shows the occlusal surface of a set of lower molar and bicuspid teeth with a pair of lines thereon indicating the relative direction of motion of the correlated teeth during mastication;

Fig. 7 shows upper and lower correlated teeth with the concavity in the occlusal surface of the lower teeth indicated by dotted lines; v

Fig. 8 .shows a curvature in the occlusal surface of the lower first bicuspid tooth; and p Fig. 9 shows a greater curvature surface of occlusion in the third molar area. I 7 Reference will now be made in greater detail to the annexedzdrawings for a morecomplete description of this invention. Figs. 1 and 2 show how the dentures are balanced, when properly constructed, to 1 prevent tilting of one by the other, during mastication. When the upper and lower dentures I and 2 are constructed, the occlusal surface of the lower teeth'3has a concave curvature laterally, as well as longitudinally, and the upper contacting area is in the form of anridgeorbrest A, the occlusal surface of the 'lowerteeth 3 being formed infacs'imile to the milled occlusal surface of the lower bite rim and the upper teeth 6 in accordance with the cement crest la, as shown in Fig. 3, the upper teeth 6 having a crest or ridge 4 constructed along the line of the lingual cusps which project downwardly into engagement withthe lower teeth 3. By a comparison of Figs. 1 and 2, it will be seen that the pressure-bearing surface of the upper teeth is maintained substantially directly in line. with the crest of; theupper gum ridge so-that" there is-no tendency to causerock ing of the upper denture l, as would be the case if the area of pressure were outside of the linesa:

and b, as in the case of an upper buccal, cusp,

contact. The position of the lower gum ridge is indicated by the lines 0 and d, therebeing-ta; greater span between 0 and 11 than between a and From Fig; 1 it is noted" that the downward pressure of the upperteethw b, in the average case.

on the lower is located inside of the lines 0 and d. This tends,.to..prevent any rocking of the lower denture 2.

From Fig. 2 it willbe. noted that. the pressure on the lower teeth at one side of. the. mouth is. buc.-, eallyfrom thegumcrest while, upon the other sideof the mouth, the. pressure is linguallyfrom the gum crest. Therefore, if there is any tendency by reason of the pressure on the buccal side of the teeth to. cause tilting of that denture upon the..gu m.ridge, the pressure on the lingual cusp at the opposite. sideof the. mouth holds. the den.- tu te down on the gum. ridge so that there is no tilting thereof, this,b.ei ng upon the working side whichdefinitely. precludes. a tilting action, It will also be seen, from, particularly, Figs. land Zpthat vvhethen the. teeth .are closed in centric position, as inFig. 1., orare laterally. displaced, as.:i.n Fig. 2., portionsofthe upper teethlie. sufflcientlyoutwardly of the. contacting ridge.- nQrtiorns l to.- prevent h cheek from bein drawn in between the upper: and. lower teeth and bitten thereby, much. tothe di comfort, and injury of the patient. I The. biterimsare formed with a slightlygreater biteopening-thannormal. Then, by aprotrusire movement of the. mandible, a? protrusive curvature is milledon the occlusalsurfaces of therbiterimsfiaand 8, as. shown in Fig. 7. Then a narrow grooveliscutinthe'upper rim along the line ofthe lingual cusps. This groove is then filled with an abrasive cement la which is sufl l ciently rigid. to maintain its: form throughout thelateral millin procedure. This cement is shown in;F!ig. 3 at la. Next, the. bite: rim is-cut away, laterally from the. cement, leaving it in the form of a prominent crest. Next, the. case. is placed in the patients, mouth. and, by. lateral movement o-fthe mandible, the curvature and in; clination are formed, as described above.

The variationv in inclination of the occlusal surface. of the lower teeth is shown by the linese and. I; Eise. t a h d draw n s, are m rely i Laud show ome oi he a ions which may occur as, a result of milled registra- .tion.

Fig; 5 shows the locationof the crest 4.011. the

es-zslusal ur e in. aa tf pp r mo a nd .bicuspidteeth. asbeing placed lingually from the cen ral line. t e e Fig. 6 shows the. occlusal, surface of a set of lower molar and bicuspid teethhavinga 0,011.- ca vity 3a produced by the, described, intraoral milling procedure. Thissurface, is provided with engraved fissures, on lines transverse to the. movemerit. oi; the. mandible. on the, lingual, ide, the

4 direction of which is indicated by the line g and h. The food is pressed into these fissures during mastication and, by the action of the upper crest in moving laterally during the act of chewing, the food is crushed and sheared.

Fig. 7 shows the buccal aspect of molar and bicuspid teeth when set in centric relation showing the spacing between the buccal cusps thereof, the dotted line showing the contact of the upper li ual; crest area with the occlusal surface of the lower-teeth midway-between the lateral borders thereof.

Fig. 8 shows the laterally milled occlusal curvatllleof a .lower first bicuspid tooth as being less than that of a lower third molar illustrated in Figit, the line... 9 indicating the former and the line vIjl indicating the latter, these being illustrative of typicalcases. The change in curvatureis, progressive between these teeth.

In order to make the; method clear, the same willnow be setout. i der-v r t. ca s. ar ade. of the Jaws. to. efit e nd nrl tos molded e hese. c t N xt. e. ms. are mo d d. h. hepla a e t e ite ms. are trinnned to approximate the bite opening although they are left a little oversize in order to have. enough. material for the milling in which follows next. Th s on st a h s me. of n: traorally milling the, protrusive curvature. When this. s.v completed. a r ov is. t ne. h ine. or. the upper lin u l o ar and. b uspid usps; When this is completed, the grooveisfilled flush withabra iye cement. whi h wills t hard. n ugh to withstand intraoral milling. The case. is then inserted nto the. pat en s mo h nd s n: structe to move th ma di le t allyr ight. and left. nt lthe cc usi n c nca i y ave been iormedinthe low r. m. and. a a ance occlus on is., stabl shed.-.

caseisthen ounted ar q ator n... attic elatio The. ment c st, is then. r

m ed. rom hempper pl t nd aced th. a h -so ened... m del omp un heo er rimbeing wet and cold; Now, withthemgdel' ine omp ndso t he r icula or i lqs li orm.- me. a oun rpar f. th o rrim. pon. the pri rbese p te. My ower t a madam confo m t he pp r ount r a thus pro: uc ne r r aof e r. m l edoc l al sura-ca Nex y p r et e' o med ith a i ext ndin l n e, areahe ngual cusps. Now, the teeth are set up with theridge so placedthat it, only, can contact the lower e ih.. d: h a p s on. subst t y midi way between the lingual and buccal borders thereof, when in centric relation. The set up teethpow. forma replica ofthe intraorally. milled bite-rims. Starting from centric position, it will be observed, from Fig. 2, that upon lateral movement; as the mandible moved rightward, the right up er. ridge ides p n' t e. ri in a lopes and, simultaneously therewith, the left upper ridge slides upon the left buccal; slopes of the ole his l; urfaces. f: e, 10Wer h.-v i a ly a themandibl'emoves leftward, the left upper ridge slides upon the left lingual slopes, of the sclusalfiu fa s he er hahd. 111.1 aneo sly e w h he i h p r. id ides uponthe right buccal slopes of the lowerocclus al ur ac s.

It s .of. ou se. nder ood, a he p ci c escr r on t ctu e et o th ov a he d'eparted'from Without departing fromthe spirit o y his nv htion asse orth h einahd as' er fiued th ppended c aim.

- 5 Having now described my invention, I claim: REFERENCES CITED denture m whlch the lower molar and 1010115 The following references are of record in the pid teeth have their occlusal surfaces formed as file of this patent; a concavity extending laterally of the mandible. the upper teeth having a longitudinally extend- 5 UNITED STATES PATENTS ing ridge on their grinding surfaces, the lateral Number Name Date curvatures of the concavity being less in the 1,681,436 Sears 1 1s e Aug. 21, 1928 first .bicuspid than in the second molar, and the 1,878,517 Hiltebrandt Sept. 20, 1932 change in curvature being progressive. 2,095,432 Brenner s Oct. 12', 1937 JASON D. KINSLEY. 10 2,168,530 Kyprie r l e Aug. 8, 1939 2,171,759 Meyer 11... Sept. 5, 1939

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