Front Cover
 Title Page
 Curriculum Vitae
 Table of Contents
 Review of the Literature
 Statement of Problem
 Experimental Procedures
 Tables and Illustrations
 Conclusions and Summary
 Back Cover


A study of mandibular movement from centric occlusion to maximum intercuspation. --
Full Citation
Permanent Link: http://ufdc.ufl.edu/AA00011622/00001
 Material Information
Title: A study of mandibular movement from centric occlusion to maximum intercuspation. --
Physical Description: 71 leaves : ill. ;
Language: English
Creator: Hodge, L. C
Publication Date: [1965]
Subjects / Keywords: Dental Occlusion, Centric   ( mesh )
Dissertations, Academic   ( mesh )
Mandible -- physiology   ( mesh )
Genre: non-fiction   ( marcgt )
Thesis: Thesis (M.S.D.)--Emory, 1965.
 Record Information
Source Institution: University of Florida
Holding Location: UF Health Science Center
Rights Management: Permissions granted by the author.
Resource Identifier: oclc - 184859877
System ID: AA00011622:00001


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Table of Contents
    Front Cover
        Front Cover 1
        Front Cover 2
    Title Page
        Title Page
    Curriculum Vitae
        Page i
        Page ii
        Page iii
        Page iv
    Table of Contents
        Page v
        Page vi
        Page 1
        Page 1a
        Page 2
        Page 3
        Page 4
    Review of the Literature
        Page 5
        Page 5a
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
    Statement of Problem
        Page 18
        Page 18a
        Page 19
    Experimental Procedures
        Page 20
        Page 20a
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 28a
        Page 29
        Page 30
        Page 31
    Tables and Illustrations
        Page 32
        Page 32a
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 45a
        Page 46
        Page 47
        Page 48
        Page 49
        Page 50
        Page 51
        Page 52
        Page 53
        Page 54
        Page 55
        Page 56
        Page 57
        Page 58
    Conclusions and Summary
        Page 59
        Page 59a
        Page 60
        Page 61
        Page 62
        Page 62a
        Page 63
        Page 64
        Page 65
        Page 66
        Page 66a
        Page 67
        Page 67a
        Page 68
        Page 69
        Page 70
        Page 71
        Page 72
    Back Cover
        Back Cover 1
        Back Cover 2
Full Text



A4.010,11A. INTERCIVISRV '11-041




A sTwa or r plA w awDn m a-MnMC
OClOSl TO mtMuM rllacrPATnno

taster Clark eBodge, Jr.

Submitted to the aculty of the Graduate School

in partial fulftiltmet of the requl.rments

for the degree f Malster of Science n Dtatistry,

IBory University School of Dentistry



The author w born in Gaineeville, Florida an
August 3, 196. HiU primary ad secadary educatten wm

received in the schools of Alcuha Couuty, rFlrida. The

author attended the Unaverettr of Florida three years fo

his pre-deutal education. O June 5, 1961, he received

his D.D.S. degree frem Miry Uaiversity School of Dentistry,

After graduate freo dental school, the author served

two year i the U.S. Anr Dental Caps. At eampletim ef

active duty, he was smrded the U.S. Arm Cm-edation

Medal for "M'acptianally eAriterllou ad faithful service."

Bis graduate study la erth edasttei was I u a July I1 1963.

The author is a umber ef the Amer an D tal AueI0atiem.

rra~ aule~ar~r

ht author vs w to pess his sasere resttutd to
Dr. lrk Mes N tfwr iM s I a hr b o uumwelfh direst Lr
tmed the prepanasreu this thers. is valuable

eeeMtrustiv c itisir hwas MW u~ah Ut the uderstaiL

t this papr.
The assiatase of Dr. Joep Radrea la em tamatlem of

the subjects ad prepart an of dhe dravafs t greatly

liMr. xishLel berrea ha e library staff h been ry

helpful lt obtalatn material tfr the ltterture rwitw.

Thiis asudy oeuld Uwm sot boen earned to aeploetem

wiLdut the use of the fasities ad the eeporatinm of

the persmel f the Armad lerses KuhaiLng Statim, Atlata,

lTh typast, Mrs. Dolores rirbusm ad the phteg raplhr,

Mr. wMllim Mmual, hbve operated with the autbhr ia the

prprwratim of thi thesis.
Detoer e rra LImms, Ilbert Up h w au Alfred villls,
S emers of te author's OGrduate Cmnttto, b ew prleved

iastrustte awd lui d e n r h~It a as ee selstm.
The anther's wife a4d ehldra l mho bmee vry umdwr-

*stoding of the problems Am elved Ia witL g *f this paper.

uoxor lW IMO

LLE or CtIhMtW-

ftita i . . . . . . . . . . X

Uehtw oft he etures. .. . . . . .

seatmet of Pr8tobE . . . .. . . . . . I,

a oettlareBtshmter Oatrut . . . 21

C. preeduret of t aaa rPositia *nthmeer. . 23
e.se ftbS u itii. * *# * * * 25

C. Pretedure rol er.t f *. *, . . 25

G. ffect of einsetiv pressure em jw postioa

tuoU,*re. * * 27

Results, ., ., . ,.. , 28

ablesand Xllsetratie n s... .... . .. 32

Dtoua . . ... . . .. * * . *45

Cuelwtei tad i S+im y. . . . . . . . 59

fc mrase e . .. . . * * . . . 62

4bSUnre . * * * * . , 6

Appisix 44 * 67



Ceuovery m st s o the deal litrature ever the

use of cearite oeclusim (1) and aeslusal peltioe (2) It

deal teehaiques requiring registraties to Jrw peoiteus.

This Otrewery also tends lato the iteidmene of the

symmeauity of enrts eneuasin antd maatm lastero;usption

(3) posttlot in the natural demtitim of am.
An accurate underrated t of the sgaifti mce of entries

oeacluiteoa d -mm4- latereospaeti. positive is bast* to

proper eelusal malysts. the author ha undertakes this

study li order to better define the relatioahip betmee

these jaw peoitia their sinitfisease to the physiolog of

oseesluso, an tU role they pUla ta Orthedeatti dtimeits.

Deftattioes eof se of the word uwed la this paper seed

to be gives, dues the nmerms ways they have been defSled

in the dental literature.

Centrie oeslusioe (1) te eselurioa of the teeth that

is the resItul t of unadbular elesure, the eodyles remaining

ai the tormdal hiage pouitiom.

Ocelusal peitimn (2) th relatiom of the mandible t

the me ille when the jaw is elwed ad the teeth ar la

enact. This madibular positti may or may sot soiaride

with entric oelusitu m.

Intfreupatton (3) The cup-to-foes relat~ishuip of th

upper nd laoer posterior teeth to sech other. The aseehl g of

cups of oppeinag teeth.


Catric relatela (4) the set poterior relative of the

mandible tho sh mlle at the wtablished vertleal diagua.

Tenratal hi*e positles (5) The terminal poeterir

position o the umitbuluar eedyle affeting htage mnawe t,

a In opening and closing of the j3m without traslatiton of

the coadyles.

Sl1te A moveml t ef the uandble frm centrie delusion

to nawl tateruespatlen when thee two positias are not


Angle ef slide he Included mile fomed by the lnter-

section oet perpendicular to the Pranteorl plane ad the path

of a point On the lwer central tnisor a the uandible move

from seatrie oelustiou to mexltm interacupatio pesitiea.

Angle of cleure The included angle famed by the Lnter-

section of a perpendicular to the Frankfort plane nd the ehord

of the last small segmet of the flnal centri re ltLto

closure are.

to this paper ocolusal position and saxitm interaupatli

will be used interchbageably.

The interested student will find that there e member

of schools of thought a to the eptimal position of the

mandible relative to the rmaill whe diagueofig ar rmestring

ia maltunetining mouth.

The Ball group (Hall (6) (7), Kurth (8), DIas (9),

d6Md (10), Boos (11), (12)) CeoMiders point about a

ullllmeter aterior to centric ocelusoea to be the oset


pbystilelest oeelnae pestim.

The Macsll school (Stallerd (13), MaCellu (A1),
Stuwrt (15), MLea (C1), lehulyer (17)) believes that

atimi tIatereapatste ad cntric welestem sabhuld be

identlal. U there is a differese betwem thee positioea ,
it is emtldered lepk4etoloe l.
The Oyi groep (Oy7i (18), sIrw (19). Huht (20),

munas (21)) believes that the mbdtbie ma be actvely or

passively mreed pe terier to atrie rneltlea (s determined

by a oethi r ucb traeti) preduteis a forced or stratid
relation. Also, this group fels that ceatrie eelusia

md amdmm interaspatile should be identical.

The Thmpaem sa heto (Thasopm (22) (23). Belie (24).

thampem a Craddoek (25)) ceoiders that rest position is
the optiml aterepestertor relatim ef the meadtble to he

emtlls up"r with to bass the diaguWsis of malfmatieL of

the deatitio.

The Hll, MCollum and yst Nheools of thought developed

Sa remlt of the seed for a better uaderstmiag of the
effects of madibull r umeemt ea febriseaslt preethetel

restertoens, Tso hepeoae school ws developed for the prpose

of taproevan rtlhdentte diqguest. oem these ides were

tauorporated anto the proothetie field.


The relatite bhtronn trtai eelia s te d ma*g
tateupatiamt bM beea staied by Hildtrd a (26). path

(27) (28), Bjwk (29), Italled (30). l soelt (31) (32).
Demooav (33) ne others. Their n wk vill be rmeimd i the

3a51 sesaI.

unlmu atf LraAm


I 1744, Pnria (34), at his descripti of umadibular

Mvmrtet, deserib-e a* vman bakwrds frh the UatUral

postern. e dftl s the natural positia of the -amible

as that positive at whish the iLaisers Oat eah sentast

eM aether. This deftiltie i ta kem to eerrespod to

seelual positive M 8s ivn by somuher (2).
Utldebramd (26) fomd that n at aen mal individuals,

seve eould retrude the aumnibl pstroter to t ecusesel

position. This distest Vried fro eomsealf milltmter to

me milllta er. In a group of ftftem persons with ualesiluis,

oely two euld retrude the mumdble fre- the ouelusal poaltlm.

On some of th eas he made ertmited tIpermuidibuar

joint raditegaph with tthe .aable lI different jaw poestims.

The radiraph were tweeed so as to supirtupeos the ea the

chkuge to emedylar peoitioa us measured. OA the othbr eaus,

the mnmt of retrusito from the eolusal postiaua wu

directly measurd ea th patLent. This mthedl ef mema unmt

aMs so givm.

Tests cauduesed by Ijork (29) es twenty ldtividual hrve

shown that the mndible y be retruded s average distean

of e millimeter frm the esrali pesitiom. as did sot

*tate te type of subjects tested or the thed of testing.

a th (27) studied 120 Australim Aboertifal obtidres.

s used the tee retruded mandiblar posetioe to daesrIe

whet it na ter t cwetric seelsiLe. lorty-tw peremt ot


the ueas eUl be retarded pstarier to the seelusl psitlam.
Be did et desrtIb his -thed or the mmt e retrauioa.
o 1949, ueath (2) studied 142 mre Austraali AberigiL a
eldlea. He u-asui the everjt directly a the subject
with Ot madibis tnse i tri seluelem. Then models of the
subject were el ted to fit togethr the w e facets
the everjet a measured. C"warimes of the .eaurmmto
shiwd that sentrit eelusir e to as or e uiwlluterm
poeteri t to th elsal position.
His fading of thu m eut of retrusem feer th diffeemt

SgrPeups were -s follow.
Age Mriber Average Iage Stadard
group eamimed etnrustem (p) Iite (r) deviatimnem)
3-6 23 0.65 0-2 0.2
7-10 33 1.65 0-5 1.13
11-14 44 1.18 0-3 0-85
S 42 0.76 0-4 1.115
Stallard (30) studied 450 eases free g 5 yS ws to
oe 50 yeas. Using the MaCollu gtthagreph he mum ted
the eas tsa setri. relate and observed the meat of
mandtu l displr emet t the e cluiea poeitim.
Be obemred that is fifty-tw peramt of the eses

cotrie eeelsitea ad th eslusal positia were met idstiesl.
et feued the displaem t oerUt be fre a fraetln of a
stilse to the idth tf a bieupid.
PIsselt (31) studied may fasets of atdibular uemeut.
Ofti the part pertaining to thi paper i.e.. mer nt fir
entrue seciusie to mlsmm inater.sptiae will be rewrie d.


it deftattio fl tamaIeuspetia is .osettally the m -M
IBucar's (3). reslet used the tm "retrdod entat
poesiti, diet" to desrtie sentice lsee item.
I* SalM d r fifty amr al deal student. tis subjtets

at s tudy were a1med to hae a- teeth ia eah quadrnt

uiaslm but only M first molar islag. All of these

paUtents wre n a te rawe o* 20-29 years. PIrses with
periodeatal dises eor uhe td received ortodeatie or

aeqilibratol presedures re eluded. subjects with

t merndmbulmr Jelat disease wre et duemied, but

perseas with perlodia elropitetalm i a the trpeemaLnbular

Joia wre m i dedr i this s tudy. eoseelt eites the wIrk
ef SIea (35) to justify Ialudts these people i hie tudy.

Uie cthed w as fellows A steel ball wm fined to

the 1tbal surftae of tbhe Iatrdemtal papilla betawe Ha

lowr ae tral in eowrs. Mith the subjest'u head fltamd

the Frmkfrt plae and secured s a sephlesrat, several

radtgrnaphu ~s mad. The eapseure that seMon teh paper

rwe mde with the adibLe in actrie wesluiem ad in

w im am teraspatiea. Centrie oerlusteR ws ebteaed after

* passive pesteier seleasg nvemen. The radlerphs vwre

traced Iraph paper as to be supempesed as the rntal

bae,. Te berAisetl limet of the graph papwr vmr played

parllel to the ellalmosLoa lim. The dist ee betwve the

steel bel@, as bshm a the traos@gs, m tabke as te amet


of uovment of the mandible fro centric occlusion to

maXmim Latercuspation.

Bs showed that the mandible at the lea r iLnisors nov

posteriorly 1.25+1.0 M ad saudally 0.9j0.75 a from the

intercuspal position. wh measured parallel to the sells-

assion lirn. tI eighty-light percent (4 out of 50) the

mandible could be displaced posterier to the selual position.

Conuernin the point antrtior to centre olusion to

which the intereuspel peoitian should be csnstructed Pseselt

writes, sI therftre usable at present to answr this

questla in sneral, but I eoaider that invesrtiatios of

Sgreater amber of sapathological cases ar desirable, s d

that investigations ef patholosgial cases will be absolutely

neessary in order to create a basis for the solution of the


Donevan (33) studied 100 naoml and 100 absmnl funatla-

tIg tapromdlnbular Joint. He used oriented sephaleltric

and teproumndibular joint adlegraphs to record variLe

aundibular peeitiens d funcatinal paths. The positions of

interest to this paper wero the oalusal position and th

position Mbwh the subject was told to retrude the mnadUble

a far as possible. At no time we the mandible forucd or

touhed by the operator.

Ne classified normal funotio of the teuporamandibular


jStats as:

1. "Interdigitatloe of buccal teeth including second molars.

2. Inclser oetactia g to an a adequate oerbtte and overjet.

3. Symetritcl dental arehs with an teeth ia buccal or
iageal version.

44 One teeth i ob quMdrat eaCld be Uisitu but had to
be replaced with a astisftatery reteratiem.

S. Patters of attrittion could not be exoesive at eoafined
to sy single teeth or se t of teeth.

6. Upon elsiang the jaws arisply inta ltanterespal
position, a clear single tap is hBead.

7i No single teeth or segBmnt of teeth could give indications
of preatre cetast or usumat mobility.

8. aseth fusnetl o of tmp rMedibfular join with no
symptes of clicklig, crepitus, pain, excessive tiredmes,
easness or strait.

9. The vrlrtes eua ena ts of the etmrte g thi system had
to funation with comfort and eaeo, casing the subject
so themes Wr distress."

e classified fimoatiea of the temple ndibular

joins as extitingt

1. "Clicktal erepitue, or patn of taepreundbular joints
during habitual rage of mandibular movements.

2. The ely dental requires t was that the subject have
coastttl g teeth t every dental rs b quadrt."

After traciag the radiegraphe o a to supertmi pe the,

he made 105 agular ad liner masuremants. Tkhe masumre ts

of Itro t to this paper depicted the ohl e is ceedylar position

freo the latreruspal peltiaa t the melIr retruded poetione.

The smn tota limner eh*ae is endyla positime frem

intereuspal positti to uMmeamlr retarded position for the normal


group ms 1.030.43 -n. Fr the alutimon group the mM

ws 0.12+.03 -. The sae m change easured parallel to

the erbite-leditory nestu line we 0.890.42 m for the

mmil groip nd 0.05j9.18 for the amlfunction graup.

A e-mslastien tf his tr data reveal that the nallest

lanterval beawen meaureat was 0.5 am

A1see il hoed that Ao the slfuma ta sroup, the

eeadyl7 are m Or OatrL r l the gloeiod foasa in the retruded

peottes uhe dipered to the sinma group.

His raw data shoed that i the anrmel group ninaet-

three parent caud recrude the maMdible. In the malfunccion

group nine percent could retrude the audible. Because the

aeal group as a whole could retrude the mandible significantly

ore chan the aalfunction group and 6ther diffaroeces which lie

alluded to but did ano discuss, he concluded that the retruded

peattieo of the mandlble is ot the plase to bagin the diaganta

ea malfunatien et the d antie.

Arvtad (36), in a study of forty-me individuals, fouad

that IL taen subjdets J e trl osaluston and madinum inercuspation

wes identical. t ten ases had to display one of the

ceedyles mullterey more the aneraforth malluster to bring

the toth to unsls iaterouspacLeu. Suiteen ocher cases

had to displeas the cedyles bilateraly more than oau*forth

sillueter to bring the teth to audits intereuspation.


His subjects consisted of sales and fastles froa 20 to

47 years old with nearly coCplete sets of teeth. "In a few

th occlusion was particularly good, although not ideal. In

a"we, one tooth or a few teeth were missing --e. U~wver,

the general clinical impression was one of good ocolusion."n

His method involved the mounting of model the

natural dentition ona lianau, Model H, Articulator. &

aneu Face-bow and a wax-bite were used t mount the models.

The van bite was taken with the aandihla in its cnatric

relation without contact of iLb teeth. The hinge axi was

arbitrarily located thirteen atilliatters anterior to chu

external auditory a~atus, on a line from Lih sLidle of the

trtasg the outer corner of the eye. Changes in posiLion

of the candylar shaft of the articulator were taken to mean

that the mandible and the condyles had to shift to bring the

teeth to the oeelUal position from centric occlusion.

Stuart (37) write, "Those patients who have good, vell-

formed teeth, arranged in wall-aligned nicely fuored arcoa

almys, as far as we have been able to observe, present a

condition in which the cuspal interdigitatiAn of the teach

agrees with condylar centricity. .W also find this true even

in soma cases of maloecluaion." He defines centric position

as that position in which both condyles are firmly seated in

their most posterior positions in the glenoid fossa. hl


goe ao to say, "'ecaue the candyle play such an im.

portant t iprt the centric position of the umadible, this

condition ha been called by Stallard 'Condylr Centricity'."

Schlmrtu (38) studied twenty-sevo individuals posaess-

ing excellent oecluasio of the teeth and apparent normal

funattio of the tepoeremandibular joints. He studied several

aspects of the positional relations of the coadyles, The

part concerned with mandibular moveamet frm centric occlusion

to maimma intercuspation will be reviewed in this paper.

He took oriented temporemadibular joint radiograph.

usiag the Doaven trmporemandibular joint rediogrephic device.

The uandible was i rest position, oaelusal position and

voluntary, Iet retruded position for the different xposures.

Three ets of oepeoite traciage were made from the teporumandibu-

lar joiat radiographs. These wresl 1) rest pomitioa to onclual.

position, 2) rest pesitieo to voluntary, most retruded position

and 3) oclusal position to voluntary retruded position.

b found that ninetrcthree percent (25 out af 27) of the

subjects could recrude the mandible from maximum interTuspation.

Addiego (39) used Poselt's nathbo-Thesiometer to study

various medibular positions. The Gnatho-Theistaimter ito

device which holds a movable, inverted modol of the mandibutla

arch and a fixed, inverted model of the amullary arch. A shaft

to present t represent the condylar axis. leasuremeant can be


tsaa fm t e e A pois l b the apparatus I., the lower
imts r point. d the tur edyler points. Thi qparMtu
musear dilferese between avrUeu posittms at the t r

jm ralve t e u m -eidltary awe. Mdiafge *ad his momur

m ao a s bdnesheaestems-a r, a mgisterew a the taStuumft
by the unted detal Mdele a ree n rde It was dtemtaed

that the msura-sts bnteee different .mdtbl r petAies

wre enrate to withtl 0.5 -.

Hs stud5td a group of eight prse~ pesseesing eallent
daentl oclueio me ad tomal funetioa of the temperamdibular

JoSint. Alseo he tavestigated a group of eight perseas with
clinically abnoemal functie of the tempoeramadular Joit@.

Retruded eanteat position was used to describe seatrl
eeelusion. Ue determined cntrit seeluita by pleainsg m

betum a thw mo illry and mandibular teeth. The subject ws
than Istrueted to "pull the lieer jaw back and aloe until

Sea teeth contacts se place the auth. seek eubjoet un
specifically seatised not to try to 'msh' the teotl after the
initial nstaet..."

e found that all subjects in both groups could retrude
the misdible from the occlal posatien. -em subjects Ln both

group hd uasymtrical cosdylar res rusim In mganttude sd/er
dtreestLe. h1 absermal group eamed to have the greatest munt

of sams trial change. The amout ft cadylar retrusioa fre

-muem latnereuspatio i the aerme group ranged frea 0.5 to


Sm and for the abumoul group it raned frtm 0 m to 1.5 m.

An ex-mintie eof his raw dat showed that the incisor

oinat dated to the left 0.5 m itn ae tastance i the normal

group and 0.5 to the left in two subjects In the abserml

group, wbm the umadible wmed from cntric oeelusiat to mximm

taereuspat ia The range of this wmvema t at the tasieer point

anteropeteriorly is the normal group w 0.5 to 1 m and in

the abeorml group 0.5 ms to 1.5 -.

bS could not scartain my goup differewes for my of the

andlbular positioes studied.

In 1957, Pooselt (32) reported usirg the Gatho*Thestimster

to euimla five lm-st complete denttitens. These teats eanfimed

the results of his earlier investigation published ia 1952 (32).

a alIe feoud that it i important to 0ces a distimtten between

cantric e slustiom ad muaaim iteriuspatio when emoidrtiag the

moments of the eodyle points In the Beas moment.

Ulrish (40) ezminred subjects for umdibulr movement. i

ork ws written it 1896. It wa translated by Po0selt

published 1i 1959. Ulrich used mall reflective silve balls n

a extaeion fixed to the lwer toeth. Double epoeure photographs

were mad with the mandible in various positions. ae of his

bservaties was that the subjects could retrude the mandible

posteriorly from the latereuspal position.

Sieher (41) used mudia ocolusal position to defins axmimu

lntreuspat,. e states that at least siaty percent of healthy

yeug adults with full eamplemet of teeth and a omrml eelusien


ua retru the uM ble 0.5 to 1.0 m frs the estaeel positit.
bjS d a sdur (42) sftudI poseetCer ai -lb r Mwi mm
a la tem tdividuaUs 20 o 3 years of ae. All C the subjects
bhad "CiteIaally od seolsties". the used a rapid fim hefger
to ta"e erial rdi.grqUS bile the subjecUts Up d, Mi sed
oslloedn. Amothsr swee me W n a of the Subjects Spelag ad
elosi their a hMi M o iit tasr, to fr pown retrestien ere

a the sOls. Iteel pellet were finae between thbe umlbualr
aemral tiri s, madibular first mesr a easeond bleAuspd d

amnliary firse uslr M asen blempUid to serv a refereom

peonte. she subjects' heede we fimad is s ephloestt ad the
uiry tube was pesttleed pe)rp ala the s ittal pine.
the raUgaprhs ms W uperporpee to detertme the menet ef

ertmuiAm poseibl.
the sm posterto mmernt with retr titie wm 0.87+1.0 m
O sempared to 0.7W10.7 orn wpom swslusag.
ls rage of retmusla wu 0.2 to 1.8 a. All torte
subjects sealU reside tm ma le ften iuatenYreptie

t r (43) used rvetnuive eeluiste to describe etri
esolacia a ti ey Me Seks (1). Salms used the toum settri

esuwiamt to m soelas1el psitine. We studied retrusive Jir

as rbaljeto wmr ilm II to 30 yeas of qa. so Uee L sm se

east we missing In s uky eubet. No ubjeaet bld mre tem Se


restored ecelusal surfaces. The patients wvar trailed to

olose the mandible in the terminal hinge position until centric

oeelusim was reached. ge used a modified ethic arch tracing

device to record mandibular movement in the egittal aad heriL

sental planes. Uis device reerded voluntary contact and

non-contact movements of the mandible performed ti the area

of ceatrie ocolusieo and maximum intercuspatLeo. JLsar

found that all aeghtem subjects could retrude the mandible

from asxdt m intereoupatiea position.

lngervall (44) examined twenty-nine wmen age 16 to 22

years and thirty-ne girls age 9 to 10 years for mandibular

movement from centre occlusite to Nmaimx tnercusupation.

All of the girls had the first elars and canines i.

neutral occlusio Io permanent teeth ere extracted and

no cross bites were present.

In the adult group, twenty-siz subjects had neutral

occlusiom and three had distal eoclusion. Six subjects had

croas bites of single teeth. A few had single toth missing.

IngervalL used a wax record to stabilize the mandible it

centric occlusion. Frontal and lateral ephalametric radio-

graphs were made with the mandible to centric occlusion and

in maximum intercuspation. Two millimater lead pellets were

fastened to the labial surface of each lateral iiseor, to

the meaio-inclial corner of the labial surface of the left

upper central incrior, a to the interirproal space between

the lower central incisors.


hrm value ebtaid, Am the 4dtes. beeaes the lit
pelss wre .~ere m ra wasita eh umtbuhls
pewitalte shde the m&es t 1itlsr aasme t a
eamierts e ajua W m IIm terwMetia. he 4i ffemees
Mre meosI d pwarllel the amaelm plume.
In the ebidra, he fweu th the ue -- dItf me
be* th M paitio e tthe sautt al glm fl OS.S.p
uo $a the vwrustl p l.S05.58 MO a-W to te trrtasl plau
0.3640.37 -. Thi e to rthe ait a p~op' s marm-
at 0.89ft.40 m ir the wittesl puOe, 1.S6O,6Jam t he
weratif ploe ad 0.h .17 u lo the forest plme. In -s
s did be f lad tiat emet o se Mute iM i mmm iat
euapau t wie the am .

RBEmmm W nldm,


rt tohe sal fla mfn e c ptImC prwmlag tur
rasmt -m orM iela am amslysi af snlamal festism.

Mta r enise btebo teh mltUy 1 thelr mLa ibe to
seartls ...ias sh e teeth esamM hs o ta i a sueasp-to
faer sent. If It et sh* Kt of the n e ible gre
emarte aseolu es toi ae slsel po ttes.l dl boewUv that
this emstsi sued be aweested it me tr -wee of the
flleuwag mas tiew ar preset. 1) t wrai-iunL r
jriat diesme, 2) wusn eMh, 3)lmse for Ipos restaraftim

of eelasl sratsm and. 4) ptes-eo l Eieem.

If a peva be thigs inest (slie) -a do Wss Met
-e of Sees saUttilas, the 4desit not rely an Is latwr

preti a o the dertl Itterntwre as to a"t mmet oft amars
rshald b sld s msalsed swe
I th ar ereasM ats ithis pruble sat be seuideUred I the
sennwaet of Class 11 (Asle) siCselerlle. Dursti semwetl n
Of theM tlr retotleM, the -eal-s f -mstalatit will seas
the ialble, through proprtleqtteA, to esltlu4d mtarrly
tI nit appears to be *ant siusptefasa rUelati. A

awurftl emtiMa ef thm eseluis la e tlesw patlite will
rwveI that thert tu a shift so the iedAble aterily to
Sbiate a usuma esuup-tef*sus relatet., aon Se lUesu
arhI t sten das amn M ew r om at ftis a uilar

mmnmt .(liSe) tos rel to his epltes sasse.


Mbw 1pwpes d ti stuy we to sa mi a rup a
ycm *"tuo te

1) DeSm* iaD*mter -a Wt e atNtA emIbalmsI A the

seXlealt pits. of the .aule a s Umeteaal t peres with

enllst esIlMsas, sunnml clitaml orc mlesekwlims.

) UMairen the latal vertt Sa m serpstertr
deMa l of .mga lmlrmlvt frtm cmtrts asealsem to

the ol.ll plWitte IA the groups emdmi.

am-^--k--J^^^^RL mOQhCD^PK&


aautismd SOlim. M bjesea msOdaa emasstei 0
tmfy~few deo"" stuasd= mi swayama pases befsb
proceed trw dltw y snntse. Iar we~ -tm. as 17 so I
yarP. 0alt a -e ao s d se. re eOU 0 M r eam
- give prelimummy a.Mts Lewr hm at yp of mslas
peseted. ren tamse 101 tjessu aw Uelased to be
Iedtwe. selat f at jesi aa a tah bmate of N
-sluts.m r I Ms ppea t this peer, tro bslte aype of
eoslasti amleseld wre emellat lm tUwina, naml lomlOtl
ad sals slustm. Type o lut e o l***** win h tim
mdibe b oe eas tsell psaitel. iftyl-few JndeJa bA
amell"s ei swuius, styawv-et sbjetls badl Wmeml
eslteewme, sd tuemsy- i)nsubtm bte ateb raM wsi.
Malnsla- s s m simfles aseodtlag to Aagl els.amtifee-
stm (45). uJ4Jte with mlestM teoth r sameider t
base a miatebnlet. Masirl' (46) idefsitias of saml
settais w o le to l aly pomus tme Latag slsai-luaIem.
be doeftead mes mtisaSs the dustitie eetulsiagle Iwa
tM eto way Uab s nly Saed tooth, sot weoiftu ei wmetim.
1r tdhia *eim,. aimellm eseliets -n doliliM as a da ititL
-nmla Iaeen cahe fm wry sUaeftly mtiMpeMd utth, se
reogulas ewenirM. Wea2r we h gef s slma i palirss-a
di ase e ha- a I ass e sl mlm |I baed m maladI a*"rm

Cas sbd y Ale, peau who nai vloduwl eamirm ajuart
saler .rn erats pres.we m sidl.


Ihe msbjest w e tuud for t trh s auber 6f isdai teeth
ad the aer Af retert esmIps, al. if ely seelea
westem tes we preset, the mmer wa resofdedw ta
md jbtdle j ioat imetlen was saile fo t9 preasene of
pef. lihda a eraptd antim during habitual rnse of
swremtes. lrv parses wvLt psallle, perlaieal eirpitattim
ti the tomprmeMdibular joiato t isludwd.
P dna.m-,ms~thmeter Oat ne *he fststta.~gmathmset

wm destlstd to -usure as the lowar iaser, marltwler
swemwnt in the osprifi~ leure plat. Those natbuer
sleeus paths wre the patha f the last st1llieters of eleure
tla etrlle relaittn i plCteoats with l slide and the path of
the lide from cen atrie l eseli to em-m Iaeoupatio
in subjeet hbartsa sIlide.
the asrtals uso sMl e strustem a the iLstment wre
.0456,.036, .022 tla renMd rel Lwre .o2 x .08 steel vwre
.036 sae stLeel Iubisl .036 OQir lakes tee solder steel
tlu., spot welder ~ a ssure-nt of Uir bndlg plitrs.
rhe Pfrleteit nat rm ihbm It f4ure 1, wa sesotrncted
la nte ftollwas aes"t:t
1) MI .036 frmeamek ws emteer ed to the appretumte
cuve of the amerter teah ef the mpper dental arh.
2) An .045 hertmetl br w- seldeed to thi frawrk.
On the free ad of ths hsai nwl bars, a .0M OmIa lek Ma
spo ided ad sold eedl tet the len Lk anil wa peoittLeed
Iplpedttrw to the fl nd bhrtsetal Smarn.
* ataik Capeesatm
anrern Califrat


3) A piece of .036 square tuiag us taheb tafrewed by
I'sntrti .022 rmm wian lae abs lubI A rl rt leak er

peot wSeldc d 0 sldgv4 to poit L he te ek thal pwrlemdlsm r
to this elataf e tuhigrt l tb ad I serted aeto t I
loek a the m, hora mIa i ea toame a vewtina mable

A) Amther i r a castratied Ite the presoal o -ef
SiSattsIri latae the v sul urt mdler leek aso to slide
laterally ia the cesrml pla n e rpmadHl to the vIrtDal

5) A ptator o emastruoted by laying the .022 wire
taing from the .B36 square taulag. ISh .An2 9r9e go filed
to a point. Itb pelate was served te, theaW look ta l
lateral mueber so a to give mstepofhltv iMnvmma i thu
gifntl plane. .022 x .0 wvire we spot aided to agh
.ma*le manioN ad to As flmvrMk, that wm fiudw relative
to Saab Of ther as to pvide usrtmang steps a eash
at the tree plasm tIa spa. grat seve -m tma la i t
eatmof t lotreete i th_ ss..i n an to plaes all
*-P--O fa o*17 m pmrpifs4s1A ** 0h ehrU .
Nemus w hbm th r ad justAle -e nI e dt b o he
petater sauld be se da ar dtastlsr In space to dtest ar
aus adrtr Nie a w t t a poit ml b ainrrm thsl
astral Lar relative t tor ahpper materlm test.


A naumun, Model C, foaebow was then modified by removing

the biteferk holder. Self-eurtag acrylic rests was added o

the coudylar markers so so to fit cofortably tas the ezteral

auditory meatuses.

Procedure Of UstPa Position-nathemeter. The patient wars sated

in a dental chair so as to be in a comfortable, upright position

for the examination. For most subjects, manually topping the

teeth rapidly together brings about relaxation of the muscles

of saseeation. Thic allowed the operator to place the

subject's mandible in the terminal hinge positiat. eor

subjects that could not quickly rela, the oeprator'os humaibill

was placed en the ienisal edge ef the pettints' lower teisors.

The usadible was then opened and closed rapidly t the petnt

at which the operators thumbnail touched the subjects' upper

iuetsors. This procedure usually permitted the operator to

plaeo these tease subjects' madibles in the tonrial hinge

posittle. This procedure eliitaated normal preprtoceptioa

impluees from the periodoutal structures reaching the moseasephalle

males of the trigeunal nerve (47). There were a very few

subjects who could not relax suffictetly to allow the author

to quickly place their mandibles it the terminal hinrg position.

These persons vre not tinluded in the study. After the moseles

of mastication were rTelxed, the patiet was trained to close

the mardible to ceatric oelusiom.

tIe Lftfn itbl steh a r mwe ltlh t tatdelible
p-el tUh se the rdtittrl e f-o y seted ltate tb
awmdl amdtam ma em. astolest held tiM fast
e eoe wlicat it pmllel to w the erwt pl .

her qpn aseria teeth Mre drte with a a d a
eett wel tasrUted lute the umSi y labtl slrnmi
trne stsAk soei d wa belted md pflNd oa th wir

hturgank d of Po mtsl -om--Ara er,. the IWmttianp cg ssse
wa thu plred ln th BIIe mi y stae r teth om to ako

the peter swall tom the fwrkwt plael (flIts 2) ad th
larwl amrt para~ rie s the ltaertwi prs eS the m diAle
feeabw (tfiure 3).

HA st eMt. bhe paStlSme' meeile el4se tat

wa sota susded tso O tee enmrotl aM"er. If dhe petator
e4 as tmkb the rweiwa e auk mey, the tmk m wowed
ad t pro edts wns repeated to otta a reerese mak.
If as ptara ematlry omehed dth rdefre marsh, de Gats

A el am"ge weas "W o as ses.e the rdie ltath s
s06 imbl aerm. The wmaiL eets M sued to tsasepetft

Deti6t, shigs


ta 0. a.6 Aftw tIei 2a4m lt4d% Of eash ,d e ,,.I. e
, -mamu S, the ptinater m itaerll a bet fie ,lltmater
t the marble wa th slseed M the d eluasl palate.
he arTda Ile*AI w- sLa i rse sd abd th amdate m aedjeed
- eto brtg tihe p)tilt aMstly to r rserse m ak. lm
thoe paser toasted the sream. irk, the rlb ta lk wore
tbr m a2slhe iad lekth e ea eh anMic amkr -e
atA mI sear t B. diftfe Is. beamm tlhe m macmAtwe
.1 eask awurabe ,r thm *f related. Te 2 hme diffeMeeia,
thIs *btatal pleidre usmur ae tdhe me mm a a petat -
the law, Ieatal r tasor relative to the frters paIne a
the aatfrpntarw r aml verstl dirnetisw and wrtlaev to

evanlad a- fellow Tea differt reift uee ade me
sAubjest. After eash readig thfe PuetAisginathitr war
re a d e the sb Jet's toei and bel replied. Sas.tetltal
skeds Vw uaed to saMly. the tes vft4u.
StaStitsu Mlethdfl the data sbtaain -, we ealsatet tastLetal*
ly As felltes
arithmIe am eao s ulted *a ei sto the
Smiua j. serMn y s tOhe Ladt Adust me.a-ms- ad a IA st
am&w ao seas observed. This O a manure oa aeersa


T.. nelat twieSlt (.5.) m, ealoslat ..meaS s
to s emuls (8), droe tl 9A whe
Ia 1 ie a u e m de m uaeas s n. lat er d
n trea tle emdi -e, ie ftem to a memse aof C

ditaperf of MaO e HM t othe m ad 4istrftb s.
ho em stan err Sf the mre ( B.3..) -M Mlalatl
aeees he bs eml, *whn aI.D. I L aSmamdfr
dMtsaten a a tohe rau d-at hed enati. t hst iad
ersE the me tos a mamn e the probate emait to fih
a mun eto e vay a7 hM i e aeplmags.

Caiatusav~Js u nson b a preltuimmy Slaept
to eslUslat the ls atl euMwe oft dhe umfmble at the
lerr tastenr, thre subjects withsrt a sle were et sted
ts ths tfolleam vw. A we. bite ws asse with th e anble
t semt lt reltle. Whpestesr Sath wr sopeated aist
as lUIetP Ister. se t eit -smatr was tfmW to dth
aper tnth Ad tmJw ealtate -aon m, Wmf ua e to usest
mmer, with ate m lise as peiss. re -m bite -e dthe r
swed, mi aa mEdble wc ciseS to until mel.uela. the
ni a *ha e o Sm wat M to anse* tM s positte.
rh ssepuft amu i7aCr mn wrU t -NMI laSedma me

eeosur of tIh taesr pta. Tohis male t l-ee to the

le betmr a p ymr-taulw e the rablem t plme ma ith
shed of the leet mfl a umt of the tl olemse aIm e


aOe Jaw t saute relatta.
ltmt euS Emefly flmage eas Jew PaJ amitts Neasureats. 1w
seinm w cheeked semd tlm see if emesstiv preu
awiU rm"ie ed4r l bqMhle the esauCIt rfltm

petit as de-tMncsad a the first me-.a.ai-. 7s first
ommtemu of theIe fIw subjjecs had mre ea that, I= all
tar rf these eae, sme tae omt scuiam ma mmldam Luternspatte
ware ideal. lTh' MNsible wa finrmy Prped at the chia

0l a way strog upward mo b)ashard forae w usma to
uaipulase the wielbile the th eralasa htai peoitLm. The
Jew, under pressure, ms then eanaluly closed to the first
peont of coat e. A visual and tattle observatie of ay
deviatio of the jew m made by the operate a the patiet
the natrasted the *slevtes thsl ab minble.



Te rsv data for the 101 subjects om aid are pressed
it the appendix, tres data were divided into different group
and were treated stattstitally as follies

The Sccuracy of the NPoWtirna athaselr was erimad
ftr te readies taken froi one subject (Table 1). The an

ead stenard deviattea for the antsropotteritr cpoament of sld

meA 0.430.15 um, Th standard error of the ma was 0.05 as
The mean vertical scaepoant wa 0.40.12 mu. The standard

arer of the mano for vertical muvemnt was 0.095 MTh

ra=Ig of the aterapeaterior measurements ws 0.20 to 0.80 m.
The range of the vertical measurements was 0.20 to 0.60 a.

In the emeellsat seclusion mgro~ twenty-hre eaot of
fifty-fou cases did uot hve an rateroptarterr sevmat of

the madible from a~mtic oeclusian to imms ia tercr patiutm.

The smen and atmdard deviation (Table 1 ) f tth anterspesterter

compoamt of the slide was 0.430 .49 m. The vertical ad
later l s pemts Were 0.450..53 ad 0.08 .23 m respectively.

The average ateropoaoterir oqpaeast of slide of thirty*
me subjects with amelleat ccluitesa who had slides Table

UI) amotle to 0.750.41 ma. Thirty cases had a nverage
vertniae capaMnet of 0.8OJ.48 M. Eight of the masellent

oeclulCas had an average lateral deviation of 0.570.26 -
In the herJsental pla .

There wre sixteen eses who bhd eeflleat eselulis ad
five r le res ared eselusal urfa es (Mable ). All ot do


mural ridges v Intauct. The m me maner terit,
vertical and lateral c moes were 0.240.33, 0.2 0.49

ad 0.07t0.23 respectively. light of those oaes had

na slide from s te srie lusita to mai- LtoersuspattIa.

The eellent ecelusiton eoup with me usps restored

and are thra fiv echlutal retoratiens emprised mawty-

tbree ease (Table I). leewa eases did not bove a slide.

The ast eatera postrir, vertical and lateral sempoats

of the slide $r this group rwre 0,35w0.43, 0.39.43 ad

0.0740.09 respectively.

urtee eases cmpriwed the emellent eMelalis group

with ea or ore cusps restored (Table VI). Only three

subjects ta this group did set preset slides. The

average atwmrap losrr campaent was 0.770 .58 m. The

average vertical mad lateral components wre 0.760,81 and

0.200.12 respectively.

Twemtyaeo cases were easidered to have nomal

aoclusiao tablea VU). Of these, ane uases did sot have

4 slide. The averege materoapeterer, vertical and lateral

canamUts of the slides were 0.520.59, 0.540.58, a4

0.100.27 respectively.

The thirteen nomal oecluasLos with slide (Tabla

ITU) had a mes eateropetrteir compeamt f slide of

0.8680.52 M. Bleve o had a average vertical


apmmpat of a. Three pAerse IL the ormal
group bed --a lateral aepemnts of slide of 0.77O0.19 a.

Of the twetyflive cases i the ailecelusiat group
(table IX), twelve did not have a slide. heir *Mr

satarepstsrtor, vertical ma lateral coupeat f lide

were 0.4 ,g69. 0.533+.65 and 0.140.35 a respectively.

0.77+0.69 n- w the moe ancerepeaterir eampaent

of slide of the th irtee caes t the malsteluestm group

in which centric eolusLem s mdm a imlereusption were

not tdeatical (Table X). h ura vertical eompeent for

these thirteen subjects as 1.020.95 im. etar of theme

caes had a uM la teral c~mpeat of 0.850.39 am.
There were seventy-st cases it the monal ad exsellet

oeelusie groups embined (Table X I). Thirty-two ease

4d not preset slides, Te assa amterepsterior, vertical

ad lateral components of slide fr this combined grap
vere 0.460.53, 0.45 +0.55 and 0.090.31 m respectively.

Of this group, forty-four eases (able 1XI) had a

wavrage steropesterir empamat of slide of 0.790.48 -m

earty-eas cases had a mema vertical epmsMt of 0.83.649 m.

Seven eases had a as lateral ecqpneMt ef 0.62M.25 W8.

The 101 cases (Table XI) had a mua sraerepesteor

epenamt of slide of 0.440.54 sm. The msa vertical md

lateral cempmaats wme 0.47+0.64 ad 0.010.29 m respectively.


forty-feo r Mses did not aveu slide.

ifty-rsvea cases f tim total group (table XE) had

a average aterepoeBtorir empqMent of slide of 0.794.54

a. Of thee, fifty-feur ases had a mn vertical campet

of 0.886 .64 a. litteen caes had a a a lateral couma nt

of 0.68jO .33 a

The rne of te anteroposterior ceapment of slide to

the 101 subjects w 0 to 2.80 a. The rmage of the

vertical ampeaet was 0 to 3.85 n. 0 to 1.29 s

vs the rang eof the lateral coampeent of slide ter all

w mean eagle ao closure as deteruind by the

procedure preseted in the Expertmntal Procedure seatte,

as thirty-eight degrees for the three cases ematiad,

This closure u gle is thatt eagle forced by the laterseatim

of perpndicular to the Frankort plane and the ehord of

the lau t small megmet of the final Centri relation closure


In the test of forced retrusiel of the me-dible, as

described in the xperluaw tal Proedure section, all four

subjects presented a mimue deviation of the maatble just

as maiums iatercuspation was obtaind. This deviation

Ms almost imperceptible.



S, OMnaVano m DaivutAtI mR( or M M E

trepeIoroer 10 0.43 0.15 0. 05 .
rt ical 1 0.4 0.1 1 0.04

Table I Test of the aiethod

arerpeterior 1 4 0.43 0.49 0.07
vertical 54 0.45 1 0.53 0.07
teral 54 0.08 0.23 0.03 +

Table II Compeaencs of slids
for all excellent occlusion cases.

coeomM Eor of CASXs m m ov m M ura OF MEA AHM
Anteropesterter 31 0.75 0.41 00
Vertical 30 0 0.80 0.4 0.09
Lateral I 8 0.57 0.26 0.09

Table III Caponamts ef slide for excellent
occlustea cases presenting a sllde.

Aterpmoestrtor 16 1 0.26 0,33 0.08
Vertical 16 0.2 1 0.49 0.12
Lateral, 16 0.071 0. 0..6

Table IV Cepoaneata of slide for exce lest
eccluaiea cases with five or lass ecelusal



or was
u- Mna

---~- r, ,

if IswM1Tr a

mmw nor meAW mu

AnterSMaterEf 2 0.35 0.43 0.09
Motiral +3 2 0.013 aO 090

table V. Cumpentsr et slide for eeellent calusLtem
with mere tha five celusal restrateias mad ao cusps

CC Haa gra nn STOAF AD W

Anf r ap eseat e 14 0.77 14 0.5 .
|!"t e ~rier 16 I F. 58

YTttetl 14 0.76 0.61
teral 0,12

Table VI. Capments *f slide fer erellent oaluasms
vith one or me cusps restored,

Ant riSBm n rer 0.52 o9 l
etiar 00.1 0.10

Table VII. Compemrts f slide for all neonul ecolustA
Gases .

CrmPOuS or case M UNvUTIOH M mm Or w M

lateral 3 0,7 0.5 0.11

Table VII. Coements of slide fer oramal eselusat
cases presenting a sflde.





FM o c"sa M o M m
ateoers eriTr as 0.46 0.49 0.14
r25 0.3 0E.5 o0.

Table It. Campments ef slide for all cass with

NgagEm uE SHaUMnn SHO D
amewar or Cas$ m I gnA TiaH NaMa 0m" M
iA palg 13 1103 0 965 0.
teral I o.i 0.39.

Table 1. Compnenst of slide for mlocclusion
casss presenting a slide.

2299M .. man MI Nsn I" av aN'

ft "Mpeagefrl 76 0.41 0. 0.3
Leal -7 0.43 b. i aS

Table XI. Campeents of slide for all excellent a
eomal ocelustei eases ebined.


L se taot 44 0.7 0.48 0 07
Iverti 1 41 0.! 5.49 0.69

I Lateral




. q


Table XIX. Compwaents of slide for excellent sad
normal ecclusion cases presenting a slide.


S ----- U-- --

mmn- I nwCa IMM I

STArMa i
SUUYA' w~i ~


mm r u&i i

La ral I to --lo 0,02 0

Table XIII. Compests *f slide for all ess.


_7 soy
15 0.u 0.5

Table XIV.

COmponImts f elide fa all ases
a slide.


Figure I.

The Positiou-Sunathmeter. All wvable ompoaaets

are perpeudicular to each other.


Figure 2.

Posittong-pathoaer r and modified facebeo

properly positioed on a subject. Te Positinti

gasthemeter is placed so as to make the pointer

parallel to the Frankfler plane.


Figure 3.


In erfer view of Posittesm-athbmeter and aditfied

facObw it place. Wbea the PositiLoa-gfaithb ter ti

properly played, the lateral mei r $ parallel

to the aterior part of the oodifted efacedw,


friure 4.


Error caused by superiorly ineliaed Poqitem-

gathometer, A'* and CS represent ueasuremmt

of the asteropasteror and vertic al coge mnat of

slide with the Poeitiou-gnathmeter related, hfr

the upper incisor, superiorly to the Frakfort

plme. Also note the differea c between Ailes



Figure S.

Errors caused by iaferiorly Laolined Poetiae-

gnathometer. AS' and CS' represet measurements

of the anteroposterior and vertical components f

olide with the Position-gasthometer related, Inm

the upper incisor, iaferiorly to the frakfort plane.

Also, ote the difference between eagles CAB and CAB'.


I gI

Effect of rotated upper permanent
arch length. A rotated maxillary
molar could possibly position the
to their ideal position.

first molar em
permanent first
bicumpids mesial

Figure 6.


Relation of horisental and vertical copaemnt

of slide to the centric relateio closure ar. Arc

of closure, AD, represents the locus of the incisor

point when the mandible closes in terminal hage

position. Note that distate rI results from

mere closure o the mandible ia termnaal hinge


Figure 7.

-----~- --------I--


,E (

Tooth prastusrtiw-wth identical aaxiumm inter-

cuspation positions before and after proper

occlueal adjustment. erw the cuspal inclines

are related to the terminal hinge locus (NJ) so as

to produce identical maxtam intercuspation

positions before and after proper occlusal adjust-


Figure 8.


J-;- I

Tooth prematuries with alteration of mxamma Later.

cuspation position following proper ocuselal

adjustment. Here the cuspal Lnellne are related

to the terminal hinge cloeure path (J) so am to

produce s greater overjet after proper ocelusal


Figure 9.



lrr the revwiw of the literature, it a bse rved

that there have bern amreus studies Of --dibular mr*-

mat fke entric cclusion to 0tm itutrewuspatin.

Thee studio hlwe appreeshed the measure. t of ls

sMwnm t In uany gs. Sam used eriesetd rodLt raphi
techaluqes ad others tried JdiffI esat --lehlea l dewLe.

Sao studios md. trhe u-rt t trow en es m y d ether

at the lower taeimers. their w eetitlers did wMe *A

mMaeurnmes, but ealy deserried bte IseveeM tI qusMts.

Mset f these papers dUi I" present imermine t *erw

inavlved to the ethod used. Poseset (31) sad bisr el (4)
wer the enly mes to adequately dewrhe their erm ISd

earurni t. These wre 0.1U md 0.18 m respetlvly.

Desvm (33), Sehmwrts (38) 4 Adl dieg (37) *btaled

the retruded poitti of the Mandtble by tsutruetlst the

patient t retrude the umanble without guides.a by bhe

*perater. It I the opinion of the author that mnet un-

trained porsens c met make this mrwm t back to centria

eealtumie. It it often found that an uatratied subject se

easily close to cantrfc scluasln once bhis able na been

s positioned by s- empriecsed operator.

Denevra (33) found that subjects with nrnual teuer-

odribular joint fmlaitioe would retrude the mndible tureer

then a proup with abser al futetie. AL 1 is the abaerme

group the eeodyle were further tfurd nd higher o the

glamid fessa when compared to the nueral group. oR

therefore concluded that thet retruded position is met the

best place to begin diagnosis of malfunctcin of the temper-

mandibular joint and acclusal function. H did not

enrsider the fact that persexe with tsmperrmndibular

jott syndrome lseo have mucle spwams, which ema liit their

retrusive movement. The typical subject with tempfor

mandibular pointt disease camnt rotrude the mandible froe

the oeelueal position beeaue *f the discomfort anrvlved.

DoMevem (33) carried his average measuruemets lit to

ene-hundreths of a tlliueter. His measurements as given

in the raw data appear to be accurate to oea-half of a

millimeter. It therefore appears to the author that

Demovan's maas should be rounded off to the nearest ens-

half millimeter,

Ceupareisn of the measurements in the literature with

these in this study ti difficult. Some of the ueasuraeunts

in the literature were made at the condyles and others at

the lewr incisors. Another factor to be considered is

whether the measurements indicate actual mevemet independent

of reference planes or movement relative to sea specified

plane. Donovan (33) gave data ftr actual aad relative

casdyla movement. His rafereace plans for relative

eaodylar movement was the auditory meatuserbital plame.

Peoselt (31) gave data for slide relative to the aslla-

amtB plems. His iasuremts were ade at the ter

iemistes Inservll's (44) mssurwm s are related the

elnusal plans nd depict the slide predated at the lever

intcsor. Rydd ad Ssandr's (42) figures give data fr

actual slide a the laser iaisors.

The are several faeters that arn affect the aseuray

of umeauramnts take with the PosiCtanmpathmeter.

Alignmt of the batgument parallel to the Frmakfert plan

msures that the nmeaurenimme md are related to th

referace plans in each patient. Acurate relatimhp to

a specified referease plea is meeseary if veMsurmit

ea different patiets are to be related mtbietleally.

This a8M be shem our clearly in figures 4 d So. AJ

represent t as atepeterter smpasat fa slide and IC

represents the vertical eempesnt of elide as uaured by

the P1esitisol-athemoter, wbm related parallel to the

Frmakfort plame. When properly related, AB It parallel to

the Frarkfort place.

In figure 6, AB' repree~ts the heriseatal measuremer

take if the Positic gsnuatheoter iS related, frar the upper

iateers, superierly with respect to tho Frankfort plae.

B'C then reprssts the vertical easuream- t m4s uaJer

this ses sedities. As can be seen, the vertical mesur nt

will be leu than ad the horlsemtal masurnmt will be

greater th n the masuremeats takB with the lstrummt



related correctly to the Frankfert plane. It theretfre

foll.m that the angle of elesure calculated here would be

less th that mnge calculated with the iaetrmeat plstitieed


Alse, the sadible sut be retained Ia entrie eclusiem

during the first set of measurmnts. If the euspal Ialimes

me steep, it to difficult to maintain this positive bUle

making the measurements. If the Sadtble movs slightly, an

error will be iatroduced.

iWhe the Pesitieo-gnathmater ws used to reserd the

nuadibular slide of me subject ton times, the range of the

antereposperior competent et slide wa 0.20 to 0.80 am and

that for the vertical c mpent wa 0.20 to 0.60 m. The

standard deviatiens fe the heri entel ad vertiel es pert it

for teo trials were 0.15 and 0.12 ms respectively. The

standard errors of the mean for these sme campents were

0.05 mad 0.04 u respectively. Moet of the measurements

clustered armud the mean within ee-teath of a millimeter.

this procedure thus provides a measure of t h ability of the

author to place the Pesitin-mnathmetor parallel to the

lrankfert pleae.

Ituart (37) states that people with well-frmed dental

arches, well-algd teeth and well-shapd teeth d net have

a slide. the siateen perseas in the esselleat eelausie


grup with itvew ee elo oealusa reeteratis Sheuld
satisfy his riteria for the type of eelust set assestate
with a slide. ThS s to set berne aut l this group besames
teit of the eases wer fomd ts haw a slide. the author
has bees emeneerd with these elht asses that 414 have
* slide. A possible eupLmaet that should be sudled
folleme 0lichbm (49) hai reported that est pmstete
eestets t cestric seluistm ee0~r the bifmerid resiam.
Lamas sd bolwe (50) t* a study f oppa first elar
retatsl *state that this teeth, when retated, U e sw me

space to the destal arch beeae of its rhabeid shppe.
PNure 6 shu bhew retatd upper first slar seeld
possibly peitles the bicuspidfs Jatal to their idal pesitiem.
It seem resemble tat less fa teeth streuture la the
primfar melars Caud allow the upper elors to rotate ramn
their liagual reoet as described by Laen and Hels,. htsi
slight uaLal pesistel o the bicuspids sght esuse a
prmturity sto sest e solusif with as esurtas lide.
Detenduaation of the presence or absene of a esrre1-
tiea betwe rotated upper first molars and iaidemse of

slide f(re cetrie oeeluaite to mnmas tonterouspatie would

therferte ua s laterestita eentinuattim of this study.

Whm ealy the subjees with a slide wre seuidered,
their amiterepestwr caypoat of slide of 0.790.34 =a to
lt the sme raise repertd by other tavetgeter. 8 aesses

ftrty-tour pmresat Of the subject to ti study did *mt


have a slide, the average enteropeterier cmpea nt L t all

eases mien to 0.o+0.54 -a. There to s statistically

sipgifient different betwem the different grups

specified is this study but defilnte treads be observed.

The ose 6nterepeaterier e mpeent or the iea llot csienUia

group with five r less soe1uoal restorations 0 .24Uj.33

a. Elght eit of stIxtm easm did set have slide. This

lw messauremmn for te emellet eelustim graup with

aie or ore cups rstwred, hoberw, 0.770.5i 8 -. Only

three out of fourteen ease ti this grop did mt have a


The differences btwMeen the variou groups n this study,

altheubh set statistically sigifictle ulggest that the

better the exclusion and the fmeer the dental r teraties,

the smaller will be the deviation from cantrie cnlusion to

nrmrm intereuapation.

Stace enly eight out of fifty-feur subjects o the

meellemt ecclusion group had a lateral omepame t to their

slides, it appears that a lateral deviation of the mandible

ar elesure from centric occlusion to maxmm interouspatiot,

it am dM mal movement. This incidence of lateral deviattem

an closure of the jw from centric ecclusion to r imn.

iantrerapatie position Is apprxluastely the sas as that

reported by Addege (39),

All of the studies reported in the literature tvelve

meurement taken dental students or people asseiated

with a dental ashol. It is very probable that sh a group


of emparitmtal subjects would have a sigtifijL tly re ater

umber t restored teeth cuspe is their arhes the the

population lns geeral. It is trhrafere believed likely that

a high incidence of Latroaemie slide were present As the

subjects studied by thee tavesLti trrs. This my accent

for the higher incidmece f slides reported to the literature

than s detected in this study.

Zola (51) in a study of the ecrpreeslbility f the
rcticular disk, showed that a to pound terse would reduce

the thickness of the disk 0.2 M at the thin area oraring

the medial pole of the cedyle. This fast may mpla i wl

all tour subjects tested showed a ntaute slide when aeessive

pressure was used to retrude the mandible. SIdd at Sander

(42) alUs showed more retrusive mrement whn a three to

fear peod retraction force was used. Nst advocates t

the hinge axis technique d not use this eaessive pressure

whae locating the hinge axis. Granger (52) describes the

pressure applied as fellows: "The operater's thb ia placed

agaeast the patient's chin, and gentle pressure is exerted

don and backward. Ho attempt ti made to shave his back...".

Poaselt (31) and SaLaar (43) described the umesmat
from eatric occlusion to maximuan ltercuspatLte. Referring

to figure 7, their descriptions ay be presented as follows.

Pgure 7 is a driving to repreaset the leaus ef the inciser
paint when the madible closes t ersat hinse position (AN).


& represents centric oceluioen. BC represents the icisr

path fre centric exclusion to -mad- Intercuspatiea.

Point C reprerats the u-au n itercuspatieo positive. S

Uo the eatinuatei eof the terminal hite path it there

were na caotat at B. 0 represents the Frnkfert pleae.

11 represent a perpendiulc r to the Frakfwt plane dram

through peint S. CSB 1 s perpeadicular to 11. J represets

the point where wre D roses C.

The Pesitiea-gsnatbhet mestur the distaenes S a4

Cl directly in the patient's muth, henh used described

in the Bxperiamtal Preedure seeatiL. The vertisal comment

of slide is represented by BE d the anteropeterter

empemmt by CRO A show n l figure 7, C can be divided

tsa tew parts. UJ Ia the amout r f the anterepetsrtr

cpemaent resulting from the leur ine ser pott moving uwrd

and forward as the andible closes from centric eelustio to

mount of incisor deviation from the terminal hinge n the

heoriental plane at the patent's oetlusal vertil dimstea.i

CB ad BE represent measurenmts made directly fa the subject.

In the three subjects having no slide (that were examined

for the agle at closure) point B corresepnds to point J at

the final ecclusal vertical dimension. Therefore, point a

would crrespond to e poitla o te ltthe inaisor point with


the rsetria relatim bhte a plae. the amle .1 clues is
the gle bhetwee a poerpi teurl to the rt kfirt plats a4
the sheord f me Ji. ekmise the s11 di4tanes Ielved,
clhd J aU e ad w W are alelu t Ldmatial. frw the purp e
fd this paper they were eu l mside idtieal. Anle Jl.

therefore cerresponds to the male of olewre SMeIwet i

the three sbjectf derived ia their Imperlstl Prceure

seaR The mean f thts mgle 1m thtrty-etbt iereM.
The male of sters (MS) Muy therefore be used
calculate the paItie (CJ) et the beristal eqpemet of
*liUd (C), which wrelts ir f tuaL nscl el taIteurrase
f Io usp at at teeth at met frm met eleur of thr

jam Is the vertical directti. Subject eight osf be used

ag aS awlmpl. tho stenpustearie -i vertitcl eompoests
muared were 1,35 *a 1.15 m respectively. the mle of

this slid fir e atrte soelase to maxti lr tereVpette

(CBB) amuss tc fifty degrees as calculated belews

tem w* 1.17391

AaIem a thix ye ot degree as te ia e t sl ms

if as- prrn elwti were present ia turtlmel HaI e .Iw,

L My be **Mtlat to be 0.90 g- fellswI


tu 308 -1

VB 1.15 Z 0.78129
S* 0.90

a t l u s equ1as 0.45 urn. This sm tht fer
subject eight, the inter pea deviated 0.45 ms poalel
to hse hrakfert plie, tar the terinta bIase elMsme path
at the eelusal vwatICel height.
this ame avera g le i af clomau used with se u im
msemurmnats 9S the emOsllet aclulsie grLip with a slide

(Tbte IZI) shwu that this group deviated 0.12 hire
the toendal hinge auseior lesur e the hwesental pane.

Is I1l96 MUutem (53) alluded to the faet that patiosJ
with a slide ould be resered adlr equilibrated bak to
searite eeeolur thums btailang mre eoerjet ote needed
Iok the eestmrutil of ater or prethetlc resteratels. It

hus bee the mperaence of the author, that n sea cses,
after seslusal adjustame making aatric eeeutrle an
nr- tCIatreusptelo ideatieal, the vuerjst w-mlitd Oeh

s I before the procedure. B-mltela t he --maunm to
md*e a subJect forty-ainse urewdes a possible eapleatie
o tbhs. The agle of slide for this eMbjet f eeSatrie
eMelsi.e to sa mi- nteruIspaien wfee 37 degree. The

a* e of ths slide is alest the ems the sMu angle

of clears p treated in tuhe RIst, Seotimr. Tie runst
that th welantt the appeal" lacims plnes to ert
thew A to the teaial hie closure path det~m Mes

ethBr or on the m s latc patia paoseti after
osea tel adjusnrtm vii be the some that befte the

PFue 8 9 shuld help clarify this *stouM t.
J nyprsate the Isue a f ea lwer posterior amp tip a
the mIdtble loses it the Mnaeal Mlwe posI tit. Mimdi
l utar upatim loaotiosn o the ler skae tip befler eoluial
adjw is represated by rM l both flaw r 8 W 9* M'

r ulp ests the losatian of this usp tlp tl oisum Lmber-
cuspotoa after "eclusel atdJusmat.

Ffiure 8 she the s spal Ilnlts related to this
leoeu la eash a wMy oa to proucs 4dtmeal maxim. later*
eu petti psitlimr of this cutp tip before after
seelusl adjustamef, thefore, in fLup e 8 a -d wa
idieseel. In fguea 8, after eclueal adjustuaet, the
emnal pesitlat of the lIevr cusp tip will reasn at M
became this point lia a the eatorie relation elesur path.
Omrtve ascluion ead Siw d in IstaesuSpti Wae s M idetS&l
to this patiet Of ad' raprew e t tb he psiat). Tlhrald
tie eMr t is se altered by the ee lusal r djuaa t pmresae.

naure 9 shws tbhe espal ILaclies related o the

elwere path so to produce a grp ter wrjet after

eaclusl adjusutmt. 1aew 9 also sS that the cntri
relation elmere path ef the lever esp tip s peeteer

to the pre-adjusamt mexmm tltercuspatie positen of
that cusp tip. berMefer, after aeelus djusaje mt the

wverjet will be increased mimes poit M' to located posterier
to point M.

I figure 8, mutmm Intereuspation heasld be at the
saM snterepetrertr petition both before di after ecelusal

adjustmma but it has because ildtical with oentrie celusiem

after this adjustment. uainnm iatereospatio in figure 9

would be mere pesterir after oeelusal adjustment uMn it

hts beoe identical with centric eclusien.
It sees resemble that the amount of eerjet presmted

after ecclusal adjustmunt depends an the relatia of the

ouspal incline plane to each ether nd their relative to

the teminal hlage path of closure. The relation f these

plmes therefore detormiaz whether midmm intercuspatiem

peint X (lPiguras 8 ad 9) lies on or anterior to the temial

htoge lecus.

The preceding provides a possible aiplnastiL fw th

acolsidrce of the eal e of slide 4di the om eallgle
eloure for apprtemutely four subjects. This aso elderly


shom chat in so paersoe pasauting Slid"s the e.dfyl.s
arme i the terminal hing posito Iem th*er amdlbei awre

in the oelusal pesitim.

P mky ad enm (54) a 1960 tlaneprated "Ltr ceatric"

er "free Cetric" ate the evaluate f their full muth

rehmbiitatim palati e. They defiuad "1ang entries"
aeclharJn that seellust hravng freedom af rmmemt

froa the hiag4aute emntrie relating to west amlruss.

The author somtarsr she ten m "Ug ctric" scsLuim to

Moe that the rwaestructed eecUitis alllam freedom *t
smavwmn from the teftlaln hiage Itou at the eriglst

ecalusal vertical dimenate, smerlly to the sod

iaterWcupatlem peettie. This freedom n o mmmnat i*

therefore represented by she distemas M1' I fiLue 9 ad

line CJ it figure 7. Pakey wI Him satae that she Lenmth

of "lemg seatril" ecolusirn varies frm patite to patent.

Th related this diatace t the Inividual patient's

itisal p adaes., seodyla guidsma *ad curve ef SpIee 4M

did set preset epific meaurmMat fe tehis diateo.

n this stady it ha. ben ehamm that it It peosabl to

earret the ocluaioen poaie toa havig a slide ad flod
that the proper entric oealuiote peoitti after erreetien

tois idtimal with the puirss wimsa Isteruaspufim

peoitit (figure 8). It is obvious that eeLuel djustamt

to the0 y a tito deWs et establish a "le seetrie"


eael.stm It Is the apln io t9 IathW thfts to these

eamem, "w ew str" stltelm yO be pLaslelotealsy

amessemry sIt th mablea mmmlly *penm a it it

protruded fr the selusal paoltaea.
If s "leg cetrte" Gemslutsn w erafully etablishsd

fra entris erAslusitn pe itioa mrtrir ly, artmn petrteT

iatrepu-atim otf eppiftu cuspal tiS li aw md still errnr ly

retuieme the rmptr-mnmlh r Jetot strustumws ubtAh

ltite peetwier mOmeat fr the esdyLes. Ift a the othe

had, the eng eatrtn" mekIxts wr lamnose tly

estrlited both peateritr al wsirt to the emalr

cblusiae pettleQti the aemsl rlafreeat f the psntr

laltseag structures m the teuprmfiuitr fJitats by the

eaipal talta M ald lon gr dlt. With such a incarrectly
established "leng centric" cclusiem, the paoterior Lniting

structures of the temperemandibular joint wvuld be vulnerable

to undue stress.

To secure data more directly applicable to orthedontic

diaguesli, a youager age group should be studied. With this

bckgreund intermatien, the author intends to continue those

studies in the various young age groups. lH feels that

this technique could be profitably used t mere accurately

study the physiolery of occlusion.





In an attempt to better define the relationship between

centric occlusion and maximum intercuspation positions of

the mandible, 101 persons were examined. The subjects

examined were classified into the following groups:

excellent occlusio, normal occlusion, and malocclusion.

A Poeition-gnathemeter was designed to measure mandibular

movement at the lower central incisor in specified closure

paths. These aandibular closure paths were: 1) the path of

the last aillimeter of closure in centric relation in patients

with no slide and, 2) the path of the slide from centric

occlusion to maximum intercuspation in subjects having slides.

The measurements made were components of the slide ti three

planes of space relative to the Frankfort plane.

The nteropeaterier copenat of slide of subjects

having a lide as found to be in the same range as reported

by other investigators. The 101 cases studied had mean

anterepeoterior, vertical and lateral components of slide of

0.44+0.54 me, 0.47+0.64 am, and 0.01+0.29 respectively.

Fifty-seven cases of the total group had an average anterepes-

tarior compoenet of slide of 0.79+0.54 -. Of these, fifty-

four cases had a mean vertical component of 0.88+0.64 am.

Fifteen cases has a mean lateral component of 0.68+0.33 am.

A higher incidence of slide has been reported in the dental

literature than was found in this study. The author attributed

this findian to the possibility that the pnerea studied

by other mather posuaseed latreic slide.

The differemres between the Trouls groups in this

tuy, although net statittieally sgai floet, esugest

that the better the occlusioa s the fwer the dental

resteratia, the seller will be the deviatiem frm

aeatre oceluseia to ums-m Lntereuspation.

xvidea was prem-ted to dminrtrate that massLve

pressure could rterude the msndibl posterior to the centric

oeelusioe positis. This mount of retrusiea W almst


Using the lositiae-pawthlmater, a methed by wbhih the

mnadibular 1agle of slide and madibular angle of elosure

auld be calculated was presented. For emple, using

the a*omptisne pressed and the data obtaieod, the author

demonstrated that in a perso presating a herimstal

complaent *f slide of 1.35 and a vertical eomepmsnt of

1.15 a, 0.90 m was the mout of the herimntal epenant

resultitng f centre relating closure of the incier


By use of diagras relating cuspal ineltass t the

terminal hinge Icus of a lower cusp point, the either

proeated an empla tioea the obserrveti that Lu sme

asUs the everjet resmns the see following correct ealus1

adJustmit while to others it t ltaerosd by this preedure.



It logically follows that in ame persons presenting slides,

the condyles are in the terminal hinge position when their

mandibles are in the occlusal position.

The possibility that rotated upper first molars may

be a factor in producing slides in otherwise excellent

seclusions was discussed. The findings of this study were

also used to provide a better understanding of "Leng centric"




1. B hmber, C.0. Crmat Clinical Dentel temlaely.
It. Lads. C.Y. MNby Co 1963, p.257.

S. Be ert, 0.0. Curret 1atea1l BaD l Temndslry.
St. Lsi. C.V.. aMby Cs. 1963, p.289.

3. ambhw, C.O.I aorrnt Caieal1 Bestal Temiaelgy.
St. Leois. C.. Masby C. 1963, p.202.

4. leaebr, C.0.: Cuerrt ClISaisl Detal mEdselqy.
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5S, makMer, C.O.: Curr-at C1itical Bstal TImSaeqy.
St. Late, :C.. Mobty Co. 193, p.269.

6. tll, I.. Full Beature Cuostmtim. J.A. sat.
16:1157-1198, 1929.

7 Ill, R.. Coatria telleti of the MNadible t tho
masille. A.. Dbet. SureSo 50105-109, 1930.

lkurthe L.. : Oulsir I ba DetLostry. J.A. Det. A.
25:1067-1070, 1938.

9. Dmn, R. I.: Newmuts mad Pesittieel elatLisu of thi
Lmdtble. J.A. Duat. A. 25:548-552, 1938.

10. am.uSl, P.A.: RIterIt Last Vertiral DlasaLtma J.A.
Deat. A. 2558494-60, 1936.

1. Beas, R.1.: Infermillary bRlation ostablisbed by
Bttihg- Paer. J.A. Dent. A. 2731192-1199, 1940.

12. Bees, R..: s Ctrlcs ad Fua tiemal Ste RelatLme.
J.A. Dat. A. 30l262.266, 1943.

13. Stallard, L Dtal Artlentutis a Onbrtedaetie
A. J.A.. D bt. A. 24s347376, 1937.

14. Macellmr, B.B. an Immnelved la Presertibag
ibeertive IBetal Remedies. Dmeo. Ites aof 'Laerst.
61:522-5355 641648 724-736; 852-46319-950, 1939.

15. Stuarn, C.B.: Atrtiulatl of -mm n ath. Det. Itls
of antrerst. 61s1029-1037; 1147-1154, 1939. 62s8-171
106-112, 1940.

16. NMcaLe, D..: DiqansMi ad Correstie of Oseelul
Delmtites Plter to Restorative Preedures. J.A. Bet.
A. 279238-938, 1939.

f -
- ^

17. SBehqler, C.L s Primeiples aqloyed a ull Deatur
Proetheesl Which May be Applied in Other Fields of
Detistry. J.A. Det. A. 1632045r-054 1929.

1s. ysi, A.$ KUa efeirb agu ri ahad ta Seheff J.
Rmsueh der Zambehlkbmfe. IV. Berlita/Tol a, 1929.

19. Broem ALs MONemmts of the MNdible met Provided
fer in Presetday Artiulatwe. J.4. Dest. A. 171
942-89, 1930.

20. iight, F.M. It Diseuesio an C.. Seaboyler tatru-
eral flatbed of etablitohti Mmtllonmmindblar Rtelatin.
J.A. Det. A. 19:1012-019, 1932. DBteouste 1019-1021.

21. Iffmre, I.L.: Proble ef Retaoblihnl Cetri~ Rolatien
Its tpertae. md Selutien. J.A. Bet. A. 2289-94,

22. Thmpson, J.R. The ltet rhetlema f the KMdible and
Its Stinlfieinmee o Dental Selat J.A. Dent. A. 33s
151-180, 1946.

23. Thplon, J.R.: The Rot u eitlen of the MHdible nad
ite Applieatten to Analysis ad Corectioa of Maloealuait.
Angle Orthedentist 19:162-187, 1949.

24. eblis, R.: Centite gistratteo in Full Deatw
Comstructio. J.A. BeDt. A. 361296-301, 1948.

IS. Thimpe, J.R. "a Craddoek, P.W. i rmetional Analysts
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26. Silderbrand, O.T. Studies Ai the Mastistery wMaramt
ef tse Umr Leaer Jaw. Skimadilt Arh. I. fihysil. 61,
Sapplmmmsta B rlta/Lolpas, 1931.

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Austrafm Aberiginal Childra. Autral. J.D. 518:5-95,

2. Hasth, J. A Fact-ladlia Imnvettltlea Gmeentus the
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Chtidr tn Central Australia. Brit. Det. J. 86s
25.293, 1949.

29. Ijerk, A.: The ace in Profleo. Sweak TaNdlhare-
didetrift 40, Supplemtta 51B, Lurd, 1947.


30. Stallard, L. Denver Suer Orthodontic Seminar., 1952.

31. Peaselt, Ulf: Stuadles I the lNbility of the Hum
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32. Pseelte, Ult: MIKomr t Ares of th Mandible. Pro.
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33. Dioneva, R.W.: A Cephalmotrle and TempersuI dibular
Joiat aediographle Study of Nerml ad Abnemal reustis
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35. BSamm J. Temporrmadibular Joint Arthrooes and its
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37. IMCollus, B.B. and Sturt, C.lE. A Research Report. South
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38. Schlrts, E.C. A Radoigraphic and Clinical Study of the
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IErellent Oeolusion of the Toeth aad Apparet Normal
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Northwestern University Detal School, Chicgo, 111., 1955.

39. Addiego, B.J.: &LGnatf O* heilmetric Study of Vrrous
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40. Ulr@ic, J. The H ian Tampermandibular Joint: UKasmaties
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42. Zydd, W.L. and Sander, All: A Study of Posterior
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43. tir, P. Cantric Ociustim a Centrie Relation. J.
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44. Iaewull, B.I sRtruded CGasse Pesltlem of madible.
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45. Andersea, G.: PrN tieal Ortheod- ctcs. Sch ed. St.
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46. Hasler, uMry oad Frahkel, J.M.s hreuleoae f
Malecclusta ln Children *ed 14 to 18 Tears. Am. J,
Orthbodoentc 37:751-7U, 1951.

47. Corbia, .Bi., ad Harrise, r,: rudatien of Msesmw phltte
Root of fifth Crnmial erve. J. NeIurphysiol. 3:
423-435, 1940.

48. Vrmeblau, A.N.: A Primr of Stalltites ftr Nom4-tastiteiL s.
New York. Hareurt, Brase 6 Warl, as.. 1958, p.39.

49. Glichetu, 1.: Clinieal Perltdeantoley. PhiladelphLa.
W. S. aunders Co. 3rd ed. 1964, p.723.

50. Lmms, 1.1. and Nolms, C.W.t Th Preblem o the Rotated
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47 246-272, 1961.

51. Zola, Albert: Morpheleogs LauLtabi Iatetrs the
Tmperaumdibular Jt J. J. Pres. Deat. 13:732-740, 1963.

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Philadelphia. J.. LippiL ott Co. 1962, p.6.

33. lonltes, G.B. The Impeorane of CeGtric Oeoltusia
Disgeelos & Treatmnt Plamag. J. Pres. DPt. 10i921-926,

54. lnky, L.D. and Mnm, A.W.: Oral ehabtitLtatm Part X.
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Geoerted Path Teohsebqu. J. ros. Deat. 10:151162, 1960.



101 subjects were exaind to measure the horuontal,

vertical and lateral compoaants of mandibular moveet frt

centric ocolusion to maximum iatercuspation position. A

Poitioa-mnathasmter wa designed to make these measuremnts.

From the data obtained, the asgle of slide w calculated

for the fifty-aevn patients having s lide. Also the

lastrument wa used o subjects without a slide to calculate

the angle of mandibular closure, the sun of which, in three

patients, was thirty-eight degrees to a perpendioular to the

Frrakfort plane. Forty-four of the subjects examined did

sot present a slide. Fifty-seven cases of the total group

had a average anteropostorior coompeast of elide fa 0.790.54

am Of these, fifty-four cases had a ma vertical component

of 0.88+0.64 a. Fifteen cases had a masa lateral ompoenat

of 0.68~0.33 mm.

The angle of closure, aad the caopoeats of slide wre

utilised to calculate the amount of the horizontal component

of slide resulting from the rotation of the incisor point

upward and forward as the mandible closes from aentric

occlusion to maiimam intercuspation. The fact that La sae

perceso presenting slides, the candyles are is the terminal

hinge poittion when their maadibles are in the oealusal position

was explained and the data are used to provide a better under-

standing of "leog centric" occlusion.



Case Type of
rkuber OQcluste-

















Excel lent


Anterepo terror


















































Camam t

























-~R---- --~1----

* SN resftortionr

** Less than fie oLsa al1 restoration

Angle fet Cusps
Slid* Reeter





19 *



50 2

40 2

69 *

43 1


65 **




0 *

24 4


0 *

0 *

54 *


40 *



Case Type e
nAbEr 0ocasias







































Cam PP

Aateropefter Yewettial
Capor et CWea9ent

1*4 1.5

1.5 1.0

0 0

0 0

0 0

1.2 0.95

0 0

0 0

0 0

0.4 0.6

0 0

0.7 1.1

1.2 0.75

0 0

0.3 0.2

0 0

0 0

0 0

0 0

0.4 0.7

0 0

0 0

0.05 0






















* We resteractls

** Lasm than five ecclusal restorati

Angle of

















-- "


Tpe of
























Anterop tarter Vertical
Camm1mmnt Cimmnlt







































C-am et























* N reItoractim

** Less tn fiven olatal reteratatas




















rrrc~r~ r ---~----~~~~

Angle ot


























--------------- ---------------- ------- -- -- --





















Angle o Cusps

61 *




63 6




Males Iilsten














Type of












































* Ye rstertiras

** Lss than five oelusal restorations



Ca Type ot

mf, ab

a t b

tatwal Antl *i
la n-- G RUliA

utepO ates Cousemast e n







Itles.tea uaI

tolteelsi Im


Maleoluatea n


lMaleslusit n





























* N Esuterattu

** Lts tha five seltwLe rasteratte



V" ?

__~___~ ~_1_

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