US2449435A - Form selector for denture prosthesis - Google Patents

Description

Sept. 14, 1948.

W. C. WHITTEMORE FORM SELECTOR FOR DENTURE PROSTHESIS 2 Sheets-Sheet 1 tEmm wnvnm WINTHROP C.WH|TTEMORIE TTORNEY Filed Feb. 1, 1946 Sept. 14, 1948.

Filed Feb. 1, 1946 SQUARE SQUARE TAPERING w. c. WHITTEMORE FORM SELEQTOR FOR DENTURE PROSTHESIS '2 Sheets-Sheet 2 TAPERING INVENTOR WINTHROP C.WH|TTEMORE Patented Sept. 14, 1948 FORE! s i on F BDENW PROSTHE-SIS,

Winthrop C. Whittemore, Bert Wash gten,

assignor to The Dentists. Supp N w k. New York, N Its @601? New York.

el m n n f'ebruary 1, 1946, Serial No. 644,866

9 Claims. 1.

It is a generally accepted principle in denture prosthesis that normal cases show the existence of quite a definite relationship between the shape of a person's face and the form of his upper cenftralincisorteeth. Thus a tapering face and a tapering central incisor go together, a squarish ia'ee goes with a square type central, an ovoid face with an ovoid central, and" so on. [It is also well recognized that in normal cases there is a proportionate size relationship between the face and tooth.

These principles have'been utilized by the profession as generalguideshelpful in the selection ofartificial teeth which will be suitedbest to the patient. A variety of devices have been invented with the objective of making the form comparisons and. facial measurements believed essential in thepractica-l application of the stated principics in the selection of teeth according to faces.

The present inventionrelates-tothis general class of de'vice, to which the art has referred variously asseleetion gauges, form finders, or tooth selectors.

It is an object of my invention to provide a -form selector which is simpler and easier to use,

which can be utilized for making both form determinations and size measurements without applying any scales orother'devices-directly to the patients-face.

As another example of the prior art, 1 cite United States Patent No. -1,5l69,893. With the type of tooth selector disclosed in that patent, form determinations could be made ithout applying a, mechanism directly to the patients face. However, direct determinations of form or size were impossible, for the operation of the instrument was leased on trial and error. It has been a further object of my invention to provide a form selection instrument which not only avoids the necessity of fitting parts to the patients face, but

which affords direct and immediate determinations of both form andsize without resort to timeconsuming trial and error methods, Other objects and advantages will appear asthe description proceeds.

In the drawings,

Fig. 1 is a side elevational View of an instrument embodying the invention in a preferred form.

figs, 2 and 3 are, enlarged detail sectional views a 2 tak n. as. thaws atria-1 a dl W PQQQXQM iniFig. :1. 1 l

Eie. 4 is a. detail iewc 'th me siirinstmtlss parency and its mounting.

or shipment.

B on a dia ra a ia t presentat' tire of: typi al; c nt -1.

In. its gene al: a ra arin t comprises aneye "1 ing-coerd nateleuide i r3 forspacins th e. tanoel from th pat a places. the. in eta bob I4 is arranged in position to be Withi ran e of: vision during sishtirislnmy pr f: construction, this plumb-hob will flutter whe the instrumentals level. but stop flu ter n when it i not.

T e pacin or si htin arm -3- p f rably i made in. tubular section b5. l5. 1 wh sh; are h nested: together like. the sections of a telescope for storage or shipmen These se t ns mar-be ma e Qf Wood, metal. plastic esins asual; ot er material as may be desi ed 12 av f un that a t ansparent mo ded mastitis wel ad ted; 9! the pu pose. In my pre er d: c n truction illustrated; the outside diameter of section IQ of; the pacing arm is sutsta.n a r e ual to the inside diameter of e t en l5 and. the side di m ter or" ect on IT is u sta tial eq al; winediameter of section it. o th each seq on i nto the othe and yet be tigh enoug t hold. Raised portions or collars l8, 13 en the sections it. and ti respectively form positioning stopsfor assembly. If desired, a slighttaipermay he formed on the outside of the tubular seotinns to the right of collars l8, 19 as viewed in Fig.1, so that as the sections are pressed home, they will be tightly held. At the end of section H a rounded tip 20. is formed or attached.

The transparency ll having the coordinate guide lines I2 is mounted in the line of sight of the eye-piece or telescope 'l D. The mounting may be interiorl-y or exteriorly of the telescope. For

illustration I have shown the latter form of l rectly supported on the tubular section l as by means of a. frame 2| fixed to a collar 22 which slides over the end of section 15 against a second, fixed, collar 23. The two collars are formed with complementary shoulders so as to provide a locking engagement at 24 which prevents turning of the transparency mounting relative to the section l5 of the spacing arm, thus preserving accurate alignment between the transparency and the eye-piece which is mounted on the same section of the spacing arm.

Thecoordinate lines 12 may be formed on the transparency by etching or otherwise, and the transparency itselfmay be formed of glass or transparent plastic. If the latter, it may be unnecessary to use asupporting frame, and the transparency'and the collar 22 may be formed integrally. V v

' The coordinate guide lines l2 comprise a series of parallel vertical and horizontal lines as shown in Fig. 4. I prefer that these lines be calibrated in relation to the magnification of the telescope I 0, length of the arm l3, and the proportionate sizelrelationship between the face and the tooth (generally considered to average 16:1), so as to give a dirct reading of tooth width and length in millimeters based upon direct observation of the coordinate lines in relation to the height and width of the patients face, as viewed in'superimposed relationship. Thus in Fig. 4 the horizontal and vertical sets of numerals designate tooth width and length in millimeters. I have found it preferable to omit the horizontal lines between i and 6, except at the extreme sides of the grid. This makes observation of the patients face easier. Also by arranging the vertical numbers 1, 6, '7, 8, 9, 10, 11, 12 at the center of the grid and 2, 3, 4, 5 at the side of the grid, reading is facilitated. Further to facilitate reading, the even numbered vertical parallels may be made slightly heavier than the odd numbered ones,

Fig." 6 gives an idea of what the observer sees when the form selector is aimed in the manner previously described. Vertical guide line 6 is used as a guide in centering the patients face laterally. The zero horizontal or top of the grid "is sighted at the normal hair-line of the patient. It will be observed that in this diagram the face measures H'units from hair-line to chin, and is lo minus 2, or 8, units wide. It is important to note that the hair at the side of the head must be disregarded in making the reading. Assuming calibration for direct reading of recom- 11mm. from gingival to incisal tip, and 8 mm. from mesial to distal at the widest part of the tooth. An idea of how the tooth size and form correspond can be obtained from a comparison of Fig. 6 with Fig. 7.

In Fig. '7 I have shown diagrammatically the approximate outline (inverted) of a square central incisor tooth superimposed on the grid.

The tooth indicated by this outline is 11 by 8 mm.

'The size selection is indicated by the readings in Fig. 6. It will be observed that approximately fnom l to 6 vertical the sides of thetooth are approximately parallel and that from 6 to 11 versuperimposed on the grid. Fig. 8 shows'what is known as the square tapering form and Fig. 9 a (full) tapering form. In the tapering form, the sides of the face and the tooth slope inwardly from approximately 1 to 11 vertical. In the square tapering form which, as the name indicates, is a combination of Figs. 7 and 9 forms, the sides are substantially parallel from about 1 to 501" 6 vertical, and from5 or 6 to 11 slope inwardly. It will be understood that the readings shown by these diagrams are illustrative only and will vary for different tooth sizes and will even vary somewhat as to form, although the representations shown may be considered as fairly typical as to form. It will also be understood that my invention is applicable to the determination and measurement of other forms and sizes than those selected for illustration and is adapted to show at a glance not only the size of tooth which is to be considered most suitable for a given patient, but also whether he isto be classified' in type as square, tapering?ovoid, square tapering, or reverse tapering, etc. The omission from the grid of the horizontal guide lines between 1 and 6, or of at least the central portion of these guidelines, is of assistancein determining type because in the square or square tapering type, the portions of the sides which are substantially parallel fall within the -1 to. 6

readings for average tooth sizes, so the vertical lines are emphasized over this area of the grid, whereas coordinates comprising both vertical and horizontal lines are emphasized where the contour curves or slopes.

Ihe sight or telescope I0 is mounted lOIhSEC- tion to of the sighting arm as by means of a tubular member 25. I prefer to make this mem ber of transparent plastic although, this is not essential. is provided with a pair of opposed-slots 25 through which extend the ends of a plate 2'! pendulously supported by a rod 28 from-a pivot such as may be provided by a hooked pin or rivet 29. The clearance between the plate 21' and the upper and lower edges of the slots 25 is such that when the line of sight, L. S.,' of the instrument departs substantially from the horizontal, the swing of the pendulum or plumb-bob I 4 will bring the plate into engagement with the upper or. lower sides of the slots, or one of them, and thus arrest movement of the bob. Also the clearance between the lateral sides of the slots 26 and the plate 2? is such that if the instrument is tilted to one side or the other, the plate will engage the sides of the slots or of one of them and arrest its motion. (In the drawings the clearance between the top, bottom and sides of the plate 21 and the sides of the slots 26 has been exaggerated for ease of illustration.) In manipulation the doctor places the tip 20 of arm l3 opposite or against the chin of his patient, holding the eyepiece and the horizontal guide lines of thetransparency. ll level. So long as the instrument is held in this level position, the plumb-bob or pendulum It will flutter because of its lightness and sensitivity. However when the level is disturbed, either by tilting the instrumentto one side or by tilting the telescope up or-down from the horizontal, the bob will stop fluttering by reason of contact of the plate, 21 with the sides of the slots 26 as described.

When in use the instrument is assembled in the manner described and as slrown in Fig. 1 When not in use, it may be taken apart for storing in a box or drawer, or for shipment. The

Near its lower end the member 25.

sections l5, l6 and H may be separated and the transparency ii removed from section l5. The three sections of the spacing arm may then be i e-assembled in reversed relationship in the manner indicated in Fig. 5.

The terms and expressions which I have employed are used in a descriptive and not a limit ing sense, and I have no intention of excluding such equivalents of the invention described, or of portions thereof, as fall within the purview of the claims.

I claim:

1. A form selector for denture prosthesis comprising a telescopic eye-piece, a transparency associated with the eye-piece having coordinate guide lines thereon, and an arm extending from the eye-piece substantially in the plane of the line of sight thereof for spacing the eye-piece from the face of a patient.

2. A form selector for denture prosthesis comprising a telescopic eye-piece, a transparency associated with the eye-piece having coordinate guide lines thereon, an arm extending from the eye-piece substantially in the plane of the line of sight thereof for spacing the eye-piece from the face of a patient, and means for indicating when the line of sight is level.

3. A form selector for denture prosthesis comprising a telescopic eye-piece mounted on a spacing arm extending in a direction substantially in the plane of the line of sight of the eyepiece, and a transparency mounted on the spacing arm forwardly of the eye-piece, the transparency having coordinate guide lines so arranged that when the eye-piece is directed toward the face of a patient the observer will see the coordinate guide lines superimposed on the patients facial contour.

4. A form selector for denture prosthesis comprising a telescopic eye-piece mounted on a spacing arm extending in a direction substantially in the plane of the line of sight of the eyepiece, a transparency mounted on the spacing arm forwardly of the eye-piece, the transparency having coordinate guide lines so arranged that when the eye-piece is directed toward the face of a patient the observer will see the coordinate guidelines superimposed on the patients facial contour, and a plumb-bob mounted in association with the spacing arm.

5. A form selector for denture prosthesis comprising a telescopic eye-piece mounted on a spacing arm extending in a direction substantially in the plane of the line of sight of the eyepiece, a transparency mounted on the spacing arm forwardly of the eye-piece, the transparency having coordinate guide lines so arranged that when the eye-pieceis directed toward the face of a patient the observer will see the coordinate guide lines superimposed on the patients facial contour, a plumb-bob mounted in association with the spacing arm, and means for arresting movement of the plumb-bob when the eye-piece is out of plumb whereby the observer can ascertain through free movement of the bob during facial measurement that his line of sight is correct.

6. A form selector and facial measurement device for denture prosthesis comprising a telescopic eyepiece, a transparency associated therewith and a means for maintaining an accurate, predetermined spacing between the eyepiece and the face of the patient; the said transparency carrying a series of coordinated guide lines calibrated in terms of tooth dimensions and so positioned that when the said eyepiece is directed toward the face of a patient the observer will see the coordinated guide lines superimposed on an image of the patients face, to ive a direct reading of tooth width and length in millimeters by the observation of the width and height of the patients face as viewed in superimposed relationship, and to emphasize the classification of the patients facial shape.

7. A form selector and facial measurement device for denture prosthesis comprising a telescopic eyepiece, a transparency associated therewith, a means for maintaining an accurate predetermined spacing between the eyepiece and the face of the patient, and a means for indicating when the line of sight of the telescopic eyepiece is level; the said transparency carrying a series of coordinated guide lines calibrated in terms,

of tooth dimensions and so positioned that when the said eyepiece is directed toward the face of a patient the observer will see the coordinated guide lines superimposed on an image of the patients face to give a direct reading of tooth width and length in millimeter by the observation of the width and height of the patients face as viewed in superimposed relationship, and to emphasize the classification of the patients facial shape.

8. A form selector and facial measurement device for denture prosthesis comprising a telescopic eyepiece, a transparency associated therewith, a means for maintaining an accurate predetermined spacing between the eyepiece and the face of the patient, and a means for indicating when the line of sight of the telescopic eyepiece is level; the said transparency carrying a series of parallel guide lines calibrated in terms of tooth dimensions and so positioned that when the said eyepiece is directed toward the face of a patient the observer will see the coordinated guide lines superimposed on an image of the patients face to give a direct reading of tooth width and length in millimeter by the observation of the width and height of the patients face as viewed in superimposed relationship, and to emphasize the classification of the patients facial shape.

9. A facial measurement device for use in denture prosthesis, comprising in combination an optical eyepiece, a transparency carrying calibrated parallel guide lines thereon, and a spacing means on which the said eyepiece and the said transparency are assembled a predetermined distance apart and which is adapted to maintain the said eyepiece and said transparency at predetermined distances from a patients face; in which the optical characteristics of the eyepiece, the calibration of the guide lines on the transparency and the distances between the patients face, the transparency and the eyepiece are so coordinated that when the image of the patients face is viewed through the transparent screen, the dimensions of a tooth suitable for that patient based on the accepted sixteen to one ratio between facial size and tooth size can be read directly on the calibrated scale of the transparency.

WINTHROP C. WI-IITTEMORE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,338,068 Bush -Apr. 27, 1920 1,469,893 Clapp Oct, 9, 1923

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