UNCLASSIFIED

AD 403 650

DEFENSE DOCUMENTATION CENTERFOR

SCIENTIFIC AND TECHNICAL INFORMATION

CAMERON STATION, ALEXANDRIA, VIRGINIA

UNCLASSIFIED

NOTICE: When government or other drawings, speci-fications or other data are used for any purposeother than in connection with a definitely relatedgovernment procurement operation, the U. S.Government thereby incurs no responsibility, nor anyobligation whatsoever; and the fact that the Govern-ment may have foruulated, furnished, or in any waysupplied the said drawings, specifications, or otherdata is not to be regarded by implication or other-wise as in any manner licensing the holder or anyother person or corporation, or conveying any rightsor permission to manufacture, use or sell anypatented invention that may in any way be relatedthereto.

SURFACE CONTOUR CHANGES AFTER

TOOTH EXTRACTION

'p:

TECHNICAL DOCUMENTARY REPORT NO. SAM-TDR-63-16

"March 1963

I USAF School of Aerospace MedicineSAerospace Medical Division (AFSC) A

Brooks Air Force Base, Texas

Task No. 775602

RFg

Qualified requesters may obtain copies of this report from ASTIA. Orders will

be expedited if placed through the librarian or other person designated to request

documents from ASTIA.

When U. S. Government drawings, specifications, or other data are used forany purpose other than a definitely related government procurement operation, the

government thereby incurs no responsibility nor any obligation whatsoever; and the

fact that the government may have formulated, furnished, or in any way supplied

the said drawings, specifications, or other data is not to be regarded by implication

or otherwise, as in any manner licensing the holder or any other person or corpora-

tion, or conveying any rights or permission to manufacture, use, or sell any patented

invention that may in any way be related thereto.

FOREWORD

This report was prepared by the following personnel in the DentalSciences Division, USAF School of Aerospace Medicine:

LUCIAN SZMYD, Lieutenant Colonel, USAF, DC

WARREN R. HESTER, Lieutenant Colonel, USAF, DC

The authors appreciate the technical help given by Technical SergeantEmily E. Taylor, Staff Sergeant Delbert L. Tolliver, Staff SergeantSamuel G. Palmer, Airman First Class Jerome B. Bloom, and AirmanThird Class William F. Baker.

ABSTRACT

The SAM Contourator, model B, was used to evaluate dimensional changes of theresidual ridge mucosa following the extraction of the maxillary second molar on twosubjects. An electronic curve-following device was employed to measure the changesin mucosal topography. The combined contourator - curve-follower error was deter-mined and found to be area dependent. The mesial migration of the maxillary thirdmolar after the extraction of the adj -•ent maxillary molar had little effect on contourchanges in the vertical plane. In the horizontal plane, however, movement of theadjacent molar into the extraction site reduced the loss in residual ridge topography.

This technical documentary report has been reviewed and is approved.

4ýBETBPAYNEJColonel, USAF, MSCChief, Operations Division

iii

SURFACE CONTOUR C(A16ES AFTER TOOTH EXTRACTION

1. INTRODUCTION sorption under immediate dentures. He re-ported that radical surgical alterations of the

The study of contour changes of the alveolar alveolar process during tooth extraction re-process following tooth extraction, alveolectomy, suited in extensive resorption of the ridgesridge extension, and other surgical procedures under immediate dentures. Lam (2) foundis of vital importance to the oral surgeon since that the rate of topographic changes of thesuch data are basic to the development of im- residual ridges reached peak activity withinproved technics in oral surgery. Reliable re- 3 to 4 weeks after tooth extraction. He re-search on this phase of oral surgery has been ported that maxillary anterior ridges main-impeded because of the time and the complicat- tained their shape under relined partialed procedures required for recording and dentures after the fifth month following toothmeasuring topographic changes of the oral extraction.mucosa during transition from alveolar toresidual ridges. The dimensional behavior of More recently Szmyd and co-workers (3)the maxillary residual ridges has been studied conducted studies on the dimensional behaviorunder conditions wherein anterior teeth are of residual ridge topography following the ex-extracted and a full or partial immediate traction of maxillary posterior teeth. Theydenture is inserted. Lisowski (1) studied the measured contour changes for 3 to 6 monthseffect of removing varying amounts of bone prior to the insertion of immediate full denturesduring an alveolectomy on alveolar ridge re- and for a total time of 300 days after tooth

Received for publication on 4 December 1962. extraction. They noted that the progressive

FIGURE 1

SAM Contourator, model B.

I2

loss in residual ridge area was still evident at by the topographic contours and express thethe postextraction time of 300 days. readout obtained in predetermined square units

(figs. 2 and 3). The curve-following deviceThis paper presents additional findings on translates the X-Y components of the topo-

the topographic changes of the oral mucosa graphic contours into an analog voltage. Thisafter tooth extraction. Also presented is the voltage is sent into the analog computer whereuse of a curve-following device to facilitate the the signal is electronically integrated. Thetask of measuring contour changes of the integral of this analog voltage represents thealveolar ridges, area of the surface contour. A detailed de-

scription of the curve-following equipment and

2. METHOD the method of operation is available (4, 5).

Mucosal surface contours were recorded byThe SAM Contourator, model B (fig. 1), means of tracings taken on dental casts. To

was used to evaluate dimensio.:al changes of obviate variations in the technic for makingthe residual ridge mucosa following tooth ex- impressions and dental casts, we standardizedtraction (3). In the present investigation, the the use of dental materials, impression trays,method for studying the dimensional behavior and temperatures and procedures in measuring,of the oral mucosa was modified in that the mixing, and timing. An index, constructedplanimeter was not used to measure contour from the hard palate area and cusp tips ofchanges. An electronic curve-following device the remaining teeth, was employed to mountwas employed to scan the area encompassed successive dental casts in an identical position.

FIGURE 8

Analog computer.

3

Surface contours were magnified, pantographi- MEASUREMENTS IN THE VERTICALcally, and scribed on stabiline paper. The AND HORIZONTAL PLANESpantographic device produced an area magni-fication of 9.3232. A photographic enlargerwas employed to magnify the surface contourswhich had been scribed on the stabiline paper,The photographic apparatus produced an areamagnification of 17.7658. After these enlarge- Lingual /Bucolments were printed, a variplotter-functional L .2ua Agenerator, in conjunction with the analog .27computer,' was employed to measure the topo-graphic changes of the alveolar ridges. An ad- AA" Cemento-enameljustment factor of 0.0060375 was employed to Junctioncorrect for the total area magnification pro-duced by the pantographic device and by the FIGURE 4photographic enlarger. Landmarks for linear measu•rements.

Analysis of procedural errors ing the distance between a line, "C-C," tangentto the crest of the maxillary residual ridge and

The combined contourator-planimeter error a second on a reference line, "A-A," drawnfor measuring surface contour changes was between the cemento-enamel junction on theanalyzed and presented in a previous com- buccal and lingual surfaces of the tooth to bemunication (3). A study was conducted to extracted (fig. 4).estimate the combined contourator-curve- Measurement in the horizontal plane "2"follower error for measuring topographic was made along a line, "B-B," drawn parallelchanges. The same contour tracings used in to and 4.257 mm. below the reference line,the previous study were also employed in the to, an g 4 ). Derointin were madepresent experiment. These contour tracings "A-A" (fig. 4). Determinations were madehad been made from three forms with different between the two points at which reference line

"B-B" intersects the contour tracings of theareas. Each of three operators made five con- residual ridge on the buccal and lingual sur-tour tracings on each of three forms. The faces.45 areas represented by these tracings wereenlarged, photographically, and measured by An adjustment factor of 0.3275 was em-the curve-following apparatus. ployed to correct for the linear magnification

Linear contour changes produced by the pantographic device.

Tooth migrationThe linear rate and distribution of the re-

sorptive process, after tooth extraction, was Since the dimensional behavior of residualalso determined from the enlarged contour ridge topography may be altered by the move-tracings which have been scribed on the ment of an adjacent tooth into the extractionstabiline paper. The landmarks used to study site, the rate of mesial migratiori of the maxil-dimensional changes of the residual ridges in lary third molar following the extraction ofthe vertical and horizontal planes are illustrated the adjacent second molar was determ'ned.in figure 4. Calipers, graduated to 0.1 mm., The contourator was used to draw a referencewere used to make these linear measurements. line on all of the dental casts in this study.

Calipers, graduated to 0.1 mm., were employedDetermination of surface contour changes to measure tooth migration. Measurements

in the vertical plane "1" was made by measur- were made on the dental casts at the crest ofthe alveolar ridge between this reference line

'variplotter, model 1100E. Functional generator, model 2.040. and the cemento-enamel junction on the mesialAnalogr computer, model 231R. Pace Electronic Associates, Inc.. sufcontehidmlrLong Branch. N. J. surface on the third molar.

4

3. CONTOURATOR STUDIES OF THE residual ridge area in case 1 was reversed inMAXILLARY SECOND MOLAR AREA case 2 because the maxillary third molar

migrated toward the extraction site.Two subjects were used in a study to meas-

ure changes in the residual ridge topography The. combined contourator-planimeter errorfollowing the extraction of a single tooth, for the SAM Contourator, model B, varied from

1.32%/ for an area of 62.29 mm. 2, and 0.77%The gingival tissues around the tooth for an area of 142.81 mm. 2 , to 0.40% for an

scheduled for extraction were examined for area of 252.95 mm. 2 The combined con-color, texture, consistency, position, and tourator- curve-follower error was determinedphysiologic form and were found to be within by using the same contour tracing used tonormal limits. No periapical pathology was determine the combined contourator-planimeternoted in the roentgenograms. The rate of error. The adjusted means and standardlinear and area contour changes of the residual deviations, determined from the analog meas-ridge topography was determined. The surface urements of the tracings, are given in table i.contours, scribed on stabiline paper, weretraced and photographed. TABLE I

Case 1. The subject was a 28-year-old male requir- Analysis of measurementsing the extraction of the maxillary right second molar.Oral examination revealed that all other posterior teeth Modelwere missing.

1 2 3Case 2. The subject was a 26-year-old male requir- Number of tracings 15 15 15

ing extraction of the maxillary left second molar. Oral Mean (mm.2 ) 62.31 141.62 253.22examination revealed that only the mandibular leftfirst and third molars were missing. The rate of mesial Standard deviation (mm.- ) .60 1.20 1.31migration of the maxillary third molar was determined. Coefficient of variation (%4) 1 .97 .84 .52

4. RESULTS AND DISCUSSION Unadjusted means and standard errors wereused to determine the coefficient of variation.

The rate at which topographic changes of The standard deviation reflects errors in con-the residual ridge occurred in cases 1 and 2 is tourator tracings, photographic enlargements,presented in figure 5. The progressive loss in

2.0

•___-_• -•.7 -.-.----"- - - - - - - - - - - - -P

, CASE /if

FIGU E 50 FIUR1

S••••AEI NO 2

Rateo . oporaph.cchang.Topor•hi change ivriclpne

to .. 0,8 NO I

.. .. . .. . . .

0,IS040 -- 1ý fi+--°.++ A,0 14 +- -i-0 + _i t) 34 + o _4oo _ 4i o °o 40 a0 20 160o 200 240 200 320 360 400 440 400

P.I -1. i. (l~lloe f midyI) PlOST EXTRACTION TIME WOAYS)

FIGURE 5 FIGURE 6

Rate of topographic change. Topographic change in vertical plane.

&0 LINGUAL BUCCAL

'2 DAYS 3I DAYSOfI -- - - - - - - - -

0 1 40 0 t G M " 1030$0 0 4 9

FIGURE 7LN U SU

Topographic change in hori-ontal plane.

BUCL LIGA

,2 ,,• DAYS 38 DAYS

I. , ,, o -' ,-o- - - , - - t

tj j Y ---- - - -

40 60 100 MO0200 040O000 3000340 400 440 480

FIGURE 7 7 SFIGURE 1

T o p chContour changes in

h a l p. iase

S.

to

3DAYS 12 DAYS '. S -,

24 DAS 54 DAYS?

Ito 4 Rs t o 0040,9

FIUR DAY FIGURE DAY

Cotu hne in cas 1.Mxlaytidmlrtoh ig tonncseS

and curve-follower measurements. Examina- Here, again, it is evident that the mesial migra-tion of the coefficient of variation indicates tion of the third molar had little effect onthat the contourator-curve-follower error is contour changes in the vertical plane. In therelated to the size of the area under investiga.- horizontal plane, however, movement of thetion. adjacent molar into the extraction site reduced

the loss in residual ridge topography.The rate of linear change of the residual

ridge topography is presented in figures 6and 7. The topographic changes of the oral The rate of mesial migration of the maxil-mucosa in the vertical plane were similar for lary third molar is presented in figure 10. Thethe two cases under investigation. The mesial distal marginal ridge of the maxillary thirdmigration of the third molar in case 2 reduced molar engaged the mesial marginal ridge ofthe rate of loss of the residual ridge topography the mandibular second molar during a portionin the horizontal plane. of the postextraction observation period, and

temporarily interrupted the mesial migrationThe rate of change in surface contours for of the maxillary third molar into the extraction

both subjects is illustrated in figures 8 and 9. site.

REFERENCES

1. Lisowski, C. S. A comparative study of the re- 3. Szmyd, L., C. F. Schuessler, A. A. Brewer, andsorption of the alveolar ridge tissues under C. M. McCall, Jr. SAM Contourator, model B-immediate dentures. Master's degree thesis, An instrument for measuring changes of surfaceNorthwestern University, Chicago, Ill., 1945. contours. SAM-TDR-62-93, Aug. 1962.

4. Jackson, A. S. Analog computation. New York:

2. Lam, R. V. Contour changes of the alveolar proc- McGraw-Hill, 1960.

ess following extractions. J. Pros. Dent. 10:25- 5. Function generator kit 17-18E. Pace Electronic32 (1960). Associates, Inc., Long Branch, N. J.

7

and curve-follower measurements. Examina- Here, again, it is evident that the mesial migra-tion of the coefficient of variation indicates tion of the third molar had little effect onthat the contourator-curve-follower error is contour changes in the vertical plane. In therelated to the size of the area under investiga- horizontal plane, however, movement of thetion. adjacent molar into the extraction site reduced

the loss ini residual ridge topography.The rate of linear change of the residual

ridge topography is presented in figures 6and 7. The topographic changes of the oral The rate of mesial migration of the maxil-mucosa in the vertical plane were similar for lary third molar is presented in figure 10. Thethe two cases under investigation. The mesial distal marginal ridge of the maxillary thirdmigration of the third molar in case 2 reduced molar engaged the mesial marginal ridge ofthe rate of loss of the residual ridge topography the mandibular second molar during a portionin the horizontal plane. of the postextraction observation period, and

temporarily interrupted the mesial migrationThe rate of change in surface contours for of the maxillary third molar into the extraction

both subjects is illustrated in figures 8 and 9. site.

REFERENCES

1. Lisowski, C. S. A comparative study of the re- 3. Szmyd, L., C. F. Schuessler, A. A. Brewer, andsorption of the alveolar ridge tissues under C. M. McCall, Jr. SAM Contourator, model B-immediate dentures. Master's degree thesis, An instrument for measuring changes of surfaceNorthwestern University, Chicago, Ill., 1945. contours. SAM-TDR-62-93, Aug. 1962.

4. Jackson, A. S. Analog computation. New York:

2. Lam, R. V. Contour changes of the alveolar proc- McGraw-Hill, 1960.ess following extractions. J. Pros. Dent. 10:25- 5. Function generator kit 17-18E. Pace Electronic32 (1960). Associates, Inc., Long Branch, N. J.

7

go

U. rs 'A

.. t

xv A- c a

o 5 0

E4. -E

O~ tONu4 ~ . 4 E-. 4 -)1

cu I, ", j 1cow c n -

cd 0

C4 00

.00

0 00co 0I 0m~

w E ,v Id- ~r '

W~ - , - as.

-0 4) cc 00 :30.0 a u,ý 0 -,ob

a)0- a ~ WU. R _ c

z ;m~o) VT 2 Is Q

CO E. 0a) Oo i0.ff 1.

4UU

&02 o

~ 10

Cý E R ~ .N

C:a '4) u .- U). x46 ) U, W-0 X obw.

00 00 -. C -

00 0~3 9 0 11 CI

'CIS . 0 41

44)

X~ 4)

'v . $! E 4) 01,

r t 4)

w. q,~ > >

cc5.- 0 go a4.. 0d >

to . 4 - - ý .&

dor o C.4~ ~

2 0 5.. 0

a r., ~ )

0i0

4)0VCo x 0 .2C = 40.

r *s -6 Cc)5

4) 4).0 0S.-t ,o~4

oc 0

0 0

t ~ * " 1 .0,