RelationshipzofzOcclusalzTraumaztozPeriodontalzDiseasez(9/13/2010)
I. Rangezofzforcezonzthezhumanzdentition
z
zPathologicalz……………………………………………………………………………..Physiologicalz→
Occlusalztramaz→zHyperocclusionz→zNormalz→zHypoocclusionz→zDisusezAtrophy
II. Variableszthatzplayzazrolezinzdeterminingzhowzthezperiodontiumzwillzreactztozazspecificzlevelzofzocclusalz
force
A. Directionzofzforce
B. Magnitudezofzforcez*whenzbitingzinzthezanteriorzonezonlyzbiteszwithz20%zofzthezforcezasztheyzdozw
henzbitingzonzthezposteriorzteeth.z
C. Durationzofzforcez*teethzarezonlyzinzcontactz16-
18zminuteszperzday,zparafunctionalzhabitzincreasezthezforcezonzteeth.zzClenching,zorzotherzparafun
ctionalzhabitszmayznotzhavezthezforcezonzthezlongzaxiszorztheztooth,zthisziszevenzworse.zBruxismzwillz
initiallyzhavezforceszinzmultiplezdirections.zzBruxismziszworsezthanzclenching.
D. Frequencyzofzoccurrence
III. Partszofzthezperiodontiumzaffectedzbyzocclusalzforces
Thezgingivazandzjunctionalzepitheliumzareznotzaffectedzbyzocclusalzforces.zzThus,zonlyzthezfollowingztiss
ueszwillzshowzclinicalzorzhistologiczsignszofzresponseztozocclusalzforce.
A. Cementum
B. PDL
C. Alveolarzbonezproperzz
*NBDEzQuestionz-
zRecessionziszNOTzcausedzbyztraumazfromzocclusion.zzGingivazandzjunctionalzepitheliazareznotzaffectedzb
yzocclusalzforceszalone.zzOcclusalzforceszmayzacceleratezthezproblem,zbutzocclusalzforceszalonezareznotzt
hezcausezofzthezproblem.
*histologyzslide,zshowingzthezABP,zcementum,zandzPDL
*Furcationzhaszdentin,zcementum,zbonezshowing,ztherezwillzbezgreaterzproblemszinzthiszarea.
IV. TraumazfromzOcclusion
A. zDefinedzaszdamageztozthezperiodontiumzcausedzbyzstresseszonzthezteethzproducedzdirectlyzorzindi
rectlyzbyzteethzinzthezopposingzjaw.zz
a. Consideredztozbezpathologic
b. Forceszofzocclusionzexceedzthezadaptivezcapacityzofzthezperiodontium
(1) PrimaryzOcclusalzTrauma
Occurszwhenzocclusalzforceszarezincreasedzandzthezamountzofzalveolarzbonezsupportzisznor
mal.
(ExcessivezForcezonzazNormalzSystem)
*Moveztoothzonezwayzorzthezother,zhavezazcompressionzsidezorztensionzside.zAreaszwithzgr
eaterzforcezonzthezbonezwillzbezatzthezcoronalzaspectzandzapicalzaspectzandzhavezazbuccalzli
ngualzpointzofzrotation.z(usuallyznotzazmesial/distal)z
ThezresultzfromzforceszinzthezhorizontalzcomponentziszanzenlargedzPDLzatzthezcoronalzandz
apicalzaspectzofztheztooth.zz
Itzmayzlookzenlargedzallzthezwayzaroundztheztooth.z
Whenzthereziszexcessivezforce,zonezwillzseezbonezabsorptionzonzthezcompressionzside.
(2) SecondaryzOcclusalzTrauma
Occurszwhenzocclusalzforceszareznormalzorzexcessivezandzthezamountzofzalveolarzbonezsup
portziszgreatlyzreduced.z
(NormalzorzExcessivezForcezonzazReducezSystem)
, *reducedzmeanszyouzhavezlostzperiodontalzsupport,zattachmentziszlostzwithznozpocketzdep
th.zzWithzreducedzsupport,zcontourszofzthezPDLzarezsimilarztozthosezofztheznormalzsystemzzandzcanz
occurzwithzexcessivezorznormalzforcezrotationzofztheztoothzcausingzenlargementzofzthezPDL.zzNorm
alzforcezonzlesszthanznormalzperiodontium.zzPeriodontallyzreducedzsystemzmeanszthatznormalzforc
ezcanzcausezsecondaryzocclusalztrauma.zzExcessivezforcezonzreducedzsystem.z
LateralzforceszonzPDLzcausezenlargement
B. Clinicalzsignszandzsymptomszofztraumazfromzocclusion
a. zMobilityzofzaffectedzteeth*z*#1zcausezofzmobilityziszinflammationz–
zSRPzandzreeval,zatzthisztime,zyouzshouldzcheckzmobilityzagain,zitzmayzdrasticallyzchangezfromzt
hezfirstzappointmentztozreeval.zz2ndzcausezisztraumazfromzocclusion,zz3rdziszreducedzperiodontiu
m/reducedzsupport.z
b. RadiographiczevidencezofzthickenedzPDLz*0.25zmmznormallyz-
zcanzdifferentiateznormalzvs.zzenlargedzonzazradiograph-
zthanzyouzcanzidentifyznormalzvs.ztraumazfromzocclusion.zz
c. Positivezhistoryzofzclenchingzorzbruxism.zz*Prolongedzforcezinzthezdirectionzofzthezlongzaxiszofzt
hezteeth.zzClenchingzgenerallyzoccurszforzazlongerzperiodzofztimezthanzbruxing.
Clenchingz=zmostzdamagingzparafunctionalzhabitzazpatientzcanzhave.zzClenchersztendztozhavez
morezpainzinzthezmorning.zzTreatmentzforbothzclenchingzandzbruxingziszaznightzguard.zzTheznig
htzguardzcostzaboutz$300,ztruezbruxerszandzclencherszarezreligiouszaboutzwearingzthezocclusalz
nightzguardandzitzwillzprotectzthemzfromzthezpossibilityzofztraumazfromzocclusion.zz
d. Missingzorztiltedzteeth.z*whenzyouzseezthis,zthezmostzcommonlyzmissingzteethzarezfirstzmolarsz
becausezofzcaries.zzNozendozbecausezofzcost,zremovalzleadsztoztiltingzofzteethzaszthez2ndzmolars
st
zdriftzintozthez1 zmolarszspacezandzcausezocclusalztraumazbecausezofztiltingzteeth.
e. Evidencezofzworkingzand/orzbalancingzsidezocclusalzinterferencez*workingzsidezcontact/zbalan
cingzsidezcontactznotzgood.zzzThezonlyztimezthiszschemeziszdesiredziszinzdentures,zworkingzandzb
alancingzcontactzatzthezsameztime.zzWhenztherezarezcuspzteethzonzdentureszdon’tzwantzthis,zitzi
szonlyzdesiredzwithzazflatzplane.
*?mostzcommonlyzfoundzonz2ndzmolars.zzHarderztozinstrument,zclean,…z?z2ndzmolarsz-
zteethzlostzfirstzinzthezmouth.
GradeszofzMobility,zcheckzusingztwozfingers,ztwozinstrumentsztozcheckzmobilityz
ClasszIz=z1zmmzmovement
ClasszIIzmobilityz=z2zmmzmobility
ClasszIIIz=zdepressablezorz>3mmmobilityznotzazgoodzprognosticzsignzforzthisztooth.
**Mostzcommonzcausezofzenlargedzpdlzisztraumazfromzocclusion.zz
Wearzfacetszonzteethzforceszcausezazwearingzawayzofzthezteeth.zLowerzteethzporcelainzcrownsz
canzcausezproblemszofzexcessivezwearzagainstztoothzstructure.z
Occlusalztraumazinzthezmouth.
PointszofzRotationzwithzForceszNotzinzLongzAxiszofzthezToothzduringzexcursivezmovementsz–
zmorezPDLzenlargement.
Pointszofzrotationzwithzforceszinzlongzaxiszofztheztooth.
f. Evidencezofzocclusalzslidezinzcentriczrelationzorzcentriczocclusion(CR/CO)z*ifzwezlookedzatzevery
onezinzthezroom,z70%zofzthezpeoplezwouldzhavezCRztozCOzslidezfromzposteriorztozanterior.zzMos
tzpeoplezhaveznozproblemzwithzthis.zTherefore,zwezdon’tzusuallyzcorrectzthis.zzIfzCR/COzslidezca
usedzdeviationzofzmandiblezcomponentzitzmayzrequirezcorrection.zzButzposteriorztozanteriorzsli
des,wezdon’tzworryzaboutzthiszaszmuch.z
g. Evidencezofzocclusalzinterferencezinzprotrusivezmandibularzmovement.zz*Idealzcontactzwithzpr
otrusiveziszonzthezcuspids,zmanyztimeszthiszoccurszonzanteriorzteeth,zthezpatientzmayzhavezmor
ezperiodontalzdiseasezthanzyouzanticipate.zPeriodontalzdiseasezusuallyzoccurszfirstzinzposteriorz
, andzthenzanteriorzwithzgeneralized.zextremezcontactszinzprotrusivezoutzonzthezcentralszandzlat
erals,zmorezperiodontalzbonezlosszthanzwouldzbezanticipatedzoccurs.z
h. Presencezofzexceptionallyzsteepzcuspalzinclines.z
*Canzbuildzthiszinzprosthodonticallyzandzintroducedztroublezfromzocclusionzandztherefore,zperi
ozproblems.
Openzcontacts,zspaces,zanteriorzflaringzallzhappenzaszpatientszagezandzthiszcanzalsozcausezperio
zproblems.zz
Teethzarezpositionedzwhereztheyzarezinzthezmouthzdueztozforceszofztheztongue,zlip,zandzbone.zz
Losszofzbonezmeanszthezlipzandztonguezmayznotzbezstrongzenoughztozholdztheztoothzinzthatzloc
ation.zz1zinz3zpatientszwithzperiodontalzdiseasezhavezanteriorzflaring.zzProtrusivezproblems.zCon
tactzonzanteriorsznotzsharedzwithzcuspids.zzFremitusziszmovementzonzfunction.
Movementzwhenzopenzbiteztogetherzexcursivezmovementztoothzmoveszevenzmore.
Fremituszseeztoothzmovezinzthezmouth
Toothzwithzcrownz=zprimezcandidatezforzfremitus;zhyperzocclusionz=zocclusalztraumazandzthiszt
oothztriedzmovingzoutzofztrauma.z
Onezcanzwatchzthezbonezlosszoverztimezdueztozhyperocclusionzthatzwaszdonezincorrectlyzprost
hetically.
Wearzfacetszmayzappearzonzcusps,zcentralszmayzbezsplintedzdueztozmobility.zzcuspidzremoveszf
orcezonzcentralszandzlaterals.zzRootzlengthzfarzlongerzthanzcuspids.
Fremituszonzprotrusivezmovement.zWantztozremovezitzifzpossible,zifzyouzseezthis.z
**NBDEzwhenziszthezfirstztimezyouzwouldzthinkzaboutzdoingzocclusalzadjustment?zzNonzsurgical
ztherapy,zafterzsurgery,zonzmaintenance,zbeforezsurgery,zatzreeval?zz
Beforezsurgeryziszthezanswer.zReevalziszthezmostzlikelyztimezyouzwouldzdozthezgrosszocclusalzad
justment.zDecreasezinzinflammationzatzthiszpointzinztimezfirstztimeztherezisztimeztozremovezgro
sszprematurities,canzdozduringzinitialzprep,zifztheyzarezreallyzbad,zbutzreevalziszthezfirstztimezyo
uzmightzsee
Whenzshouldzdefinitivezocclusalzadjustmentzshouldzbezdone?zzInitial,zreeval,zbeforezsurgery,zaf
terzsurgery,zorzatzmaintenance.
Answerz=zafterzsurgery,zbutzitzcanzalsozbezdonezatzmaintenance.zzMostzofztheztimezoneziszthinki
ngzaboutzdoingzanzocclusalzadjustmentzimmediatelyzafterzmaintenance.
Mobilityzofztoothziszthezsamezorzbetterzafterzsurgeryz–
zsurgeryzneverzmakeszmobilityzworse.zzBestzcasezwillzbezimprovedzmobilityzstatus,zworstzcasezis
ztheztoothzwillzhavezthezsamezmobility.
Grosszprematurityz=zprematurityzthatzoccurszinzcentriczocclusion,zthezfirstzpointzofzthezzinitialzc
ontactziszinzCOzonzazmaxillaryzbicuspid.zzProsthodontistzsayszfirstzcontactziszinzCRzonzsecondzmol
ars
C. Histopathologyzofztraumazfromzocclusionz(compressionzside)
a. zCompressionzofzPDLzfiberszwithzinitialzdecreasezinzwidthzofzPDLzspace
b. LosszofzPDLzfiberzorientation
c. RupturezofzcapillarieszandzhemorrhagezintozPDLzperivascularzspaces
d. ResorptionzofzalveolarzbonezproperzfollowedzbyzwideningzofzPDLzspace
e. Ifzsevere,zrootzresorptionzmayzoccur
?*incidencezofzrootzresorptionzinzorthozcasesz16-
20%zofztheztimezthereziszrootzresorption.zzExcessivezforcezcauseszrootzresorptionzduringzortho.z
D. Histopathologyzofztraumazfromzocclusionz(tensionzside)
a. zTensionz(stretchingzofzfiberszwithzinitialzincreasezinzPDLzspace)zMovingztheztoothzawayzstretchz
toozmuch.z
b. RupturezofzPDLzfiberzbundles
, c. CompressionzofzPDLzcapillarieszandzhemorrhagezintozPDLzperivascularzspaceszconstrictszthezc
apillarieszandzcompromiseszvascularizationztozthezarea.zz
d. AppositionzofznewzalveolarzbonezproperzfollowedzbyzazdecreasezinzPDLzspace.zz*Mayzbuildzbon
ezonztheztensionzsidezandzlosezbonezonzthezcompressionzside.z
e. Ifzsevere,zcementalztearingzmayzoccurz*ifzthezcementalztearingzoccurs,zitztakeszsomeztimezforzt
hezbodyztozresorbzcementumzinzthezpdlzspace.z
*Thinkzofzorthozmovement,zifzaztoothziszmovedztozquicklyzinzorthodontics,zitzwillzresultzinzprobl
ems.z
Mayzgetzazmoatzlikezdefectzsurroundingztheztooth,zthiszmayzbezpathoneumoniczfromztraumazfr
omzocclusion.
Animalzmodel,zwithzrubberzdamzinzmesialzdistalzandzthenzonezotherzpoint,zcanzproducezocclus
alztraumazandzdefectszinzthezbonezratherzquicklyzinzazmonkeyzorzdogz(poorzpuppies)
V. OcclusalzHyperfunction
A. Resultszfromzslightzincreasezinzocclusalzforce
B. Consideredztozbezazphysiologiczadaptationzandznotzazpathologiczentityz**mostzcommonlyzoccurszin
zazclasszIIzrestorationthatziszaccidentallyzleftzhigh.
ClinicalzSymptomszofzocclusalzhyperfunction
Manyzofzthezsamezclinicalzsymptomszarezassociatedzwithztraumazfromzocclusionz–
zbutzalwayszthezfollowing
a. IncreasedzwidthzofzPDL
b. Increasedzwidthzandzdensityzofzthezradiographiczlaminazdura
c. Slightzincreasezinztoothzmobilityzwhichzmayzbezundetectable.z
d. Radiographiczevidence
VI. OcclusalzHypofunction
A. Azmildzweakeningzofztheztoothzsupportingzstructureszdueztozazlackzofzphysiologiczstimulation
B. Consideredztozbezazphysiologiczadaptationzandznotzazpathologiczentity
C. Canzonlyzbezdiagnosedzonzbasiszofzdentalzhistory
Histopathologyzofzocclusalzhypofuntion
a. DecreasezinznumberzofzPDLzfiberzbundles
b. Decreasedzphysiologiczturnoverzandzremodelingzofzalveolarzbone
c. NarrowingzofzPDLzspace.z
d. ***TQ:zNozchangezinztoothzmobilityzoccurszwithzhypofunction!!!!
VII. DisusezAtrophy
A. zTotalzremovalzofzocclusalzforceszresultingzinzazlackzofzthezlevelzofzphysiologiczstimulationzrequiredzt
ozmaintainznormalzformzandzfunction.z
PhysiologiczadapatationzandzNOTzconsideredzpathologic
a. zClinicalzsymptomszofzdisusezatrophy
(1) RadiographiczevidencezofzdecreasedzwidthzofzPDLzspace
(2) Increasedztoothzmobilityziszalwayszpresentz(?)
(3) Absencezofzocclusalzantagonist
b. Histopathologyzofzdisusezatrophy
(1) LosszofzorientationzofzthezprinciplezfiberzbundleszofzthezPDL
(2) NarrowedzPDLzwidth
(3) Significantzdecreasezinznumberzofzbonyztrabeculae,zi.e.,zlocalizedzosteoporosis.
VIII. Traumazfromzocclusionzinzthezabsencezofzinflammationzdoesznotzcause
A. Gingivitis******TQ
B. Periodontitis******TQ
C. Pocketzformation******TQ
I. Rangezofzforcezonzthezhumanzdentition
z
zPathologicalz……………………………………………………………………………..Physiologicalz→
Occlusalztramaz→zHyperocclusionz→zNormalz→zHypoocclusionz→zDisusezAtrophy
II. Variableszthatzplayzazrolezinzdeterminingzhowzthezperiodontiumzwillzreactztozazspecificzlevelzofzocclusalz
force
A. Directionzofzforce
B. Magnitudezofzforcez*whenzbitingzinzthezanteriorzonezonlyzbiteszwithz20%zofzthezforcezasztheyzdozw
henzbitingzonzthezposteriorzteeth.z
C. Durationzofzforcez*teethzarezonlyzinzcontactz16-
18zminuteszperzday,zparafunctionalzhabitzincreasezthezforcezonzteeth.zzClenching,zorzotherzparafun
ctionalzhabitszmayznotzhavezthezforcezonzthezlongzaxiszorztheztooth,zthisziszevenzworse.zBruxismzwillz
initiallyzhavezforceszinzmultiplezdirections.zzBruxismziszworsezthanzclenching.
D. Frequencyzofzoccurrence
III. Partszofzthezperiodontiumzaffectedzbyzocclusalzforces
Thezgingivazandzjunctionalzepitheliumzareznotzaffectedzbyzocclusalzforces.zzThus,zonlyzthezfollowingztiss
ueszwillzshowzclinicalzorzhistologiczsignszofzresponseztozocclusalzforce.
A. Cementum
B. PDL
C. Alveolarzbonezproperzz
*NBDEzQuestionz-
zRecessionziszNOTzcausedzbyztraumazfromzocclusion.zzGingivazandzjunctionalzepitheliazareznotzaffectedzb
yzocclusalzforceszalone.zzOcclusalzforceszmayzacceleratezthezproblem,zbutzocclusalzforceszalonezareznotzt
hezcausezofzthezproblem.
*histologyzslide,zshowingzthezABP,zcementum,zandzPDL
*Furcationzhaszdentin,zcementum,zbonezshowing,ztherezwillzbezgreaterzproblemszinzthiszarea.
IV. TraumazfromzOcclusion
A. zDefinedzaszdamageztozthezperiodontiumzcausedzbyzstresseszonzthezteethzproducedzdirectlyzorzindi
rectlyzbyzteethzinzthezopposingzjaw.zz
a. Consideredztozbezpathologic
b. Forceszofzocclusionzexceedzthezadaptivezcapacityzofzthezperiodontium
(1) PrimaryzOcclusalzTrauma
Occurszwhenzocclusalzforceszarezincreasedzandzthezamountzofzalveolarzbonezsupportzisznor
mal.
(ExcessivezForcezonzazNormalzSystem)
*Moveztoothzonezwayzorzthezother,zhavezazcompressionzsidezorztensionzside.zAreaszwithzgr
eaterzforcezonzthezbonezwillzbezatzthezcoronalzaspectzandzapicalzaspectzandzhavezazbuccalzli
ngualzpointzofzrotation.z(usuallyznotzazmesial/distal)z
ThezresultzfromzforceszinzthezhorizontalzcomponentziszanzenlargedzPDLzatzthezcoronalzandz
apicalzaspectzofztheztooth.zz
Itzmayzlookzenlargedzallzthezwayzaroundztheztooth.z
Whenzthereziszexcessivezforce,zonezwillzseezbonezabsorptionzonzthezcompressionzside.
(2) SecondaryzOcclusalzTrauma
Occurszwhenzocclusalzforceszareznormalzorzexcessivezandzthezamountzofzalveolarzbonezsup
portziszgreatlyzreduced.z
(NormalzorzExcessivezForcezonzazReducezSystem)
, *reducedzmeanszyouzhavezlostzperiodontalzsupport,zattachmentziszlostzwithznozpocketzdep
th.zzWithzreducedzsupport,zcontourszofzthezPDLzarezsimilarztozthosezofztheznormalzsystemzzandzcanz
occurzwithzexcessivezorznormalzforcezrotationzofztheztoothzcausingzenlargementzofzthezPDL.zzNorm
alzforcezonzlesszthanznormalzperiodontium.zzPeriodontallyzreducedzsystemzmeanszthatznormalzforc
ezcanzcausezsecondaryzocclusalztrauma.zzExcessivezforcezonzreducedzsystem.z
LateralzforceszonzPDLzcausezenlargement
B. Clinicalzsignszandzsymptomszofztraumazfromzocclusion
a. zMobilityzofzaffectedzteeth*z*#1zcausezofzmobilityziszinflammationz–
zSRPzandzreeval,zatzthisztime,zyouzshouldzcheckzmobilityzagain,zitzmayzdrasticallyzchangezfromzt
hezfirstzappointmentztozreeval.zz2ndzcausezisztraumazfromzocclusion,zz3rdziszreducedzperiodontiu
m/reducedzsupport.z
b. RadiographiczevidencezofzthickenedzPDLz*0.25zmmznormallyz-
zcanzdifferentiateznormalzvs.zzenlargedzonzazradiograph-
zthanzyouzcanzidentifyznormalzvs.ztraumazfromzocclusion.zz
c. Positivezhistoryzofzclenchingzorzbruxism.zz*Prolongedzforcezinzthezdirectionzofzthezlongzaxiszofzt
hezteeth.zzClenchingzgenerallyzoccurszforzazlongerzperiodzofztimezthanzbruxing.
Clenchingz=zmostzdamagingzparafunctionalzhabitzazpatientzcanzhave.zzClenchersztendztozhavez
morezpainzinzthezmorning.zzTreatmentzforbothzclenchingzandzbruxingziszaznightzguard.zzTheznig
htzguardzcostzaboutz$300,ztruezbruxerszandzclencherszarezreligiouszaboutzwearingzthezocclusalz
nightzguardandzitzwillzprotectzthemzfromzthezpossibilityzofztraumazfromzocclusion.zz
d. Missingzorztiltedzteeth.z*whenzyouzseezthis,zthezmostzcommonlyzmissingzteethzarezfirstzmolarsz
becausezofzcaries.zzNozendozbecausezofzcost,zremovalzleadsztoztiltingzofzteethzaszthez2ndzmolars
st
zdriftzintozthez1 zmolarszspacezandzcausezocclusalztraumazbecausezofztiltingzteeth.
e. Evidencezofzworkingzand/orzbalancingzsidezocclusalzinterferencez*workingzsidezcontact/zbalan
cingzsidezcontactznotzgood.zzzThezonlyztimezthiszschemeziszdesiredziszinzdentures,zworkingzandzb
alancingzcontactzatzthezsameztime.zzWhenztherezarezcuspzteethzonzdentureszdon’tzwantzthis,zitzi
szonlyzdesiredzwithzazflatzplane.
*?mostzcommonlyzfoundzonz2ndzmolars.zzHarderztozinstrument,zclean,…z?z2ndzmolarsz-
zteethzlostzfirstzinzthezmouth.
GradeszofzMobility,zcheckzusingztwozfingers,ztwozinstrumentsztozcheckzmobilityz
ClasszIz=z1zmmzmovement
ClasszIIzmobilityz=z2zmmzmobility
ClasszIIIz=zdepressablezorz>3mmmobilityznotzazgoodzprognosticzsignzforzthisztooth.
**Mostzcommonzcausezofzenlargedzpdlzisztraumazfromzocclusion.zz
Wearzfacetszonzteethzforceszcausezazwearingzawayzofzthezteeth.zLowerzteethzporcelainzcrownsz
canzcausezproblemszofzexcessivezwearzagainstztoothzstructure.z
Occlusalztraumazinzthezmouth.
PointszofzRotationzwithzForceszNotzinzLongzAxiszofzthezToothzduringzexcursivezmovementsz–
zmorezPDLzenlargement.
Pointszofzrotationzwithzforceszinzlongzaxiszofztheztooth.
f. Evidencezofzocclusalzslidezinzcentriczrelationzorzcentriczocclusion(CR/CO)z*ifzwezlookedzatzevery
onezinzthezroom,z70%zofzthezpeoplezwouldzhavezCRztozCOzslidezfromzposteriorztozanterior.zzMos
tzpeoplezhaveznozproblemzwithzthis.zTherefore,zwezdon’tzusuallyzcorrectzthis.zzIfzCR/COzslidezca
usedzdeviationzofzmandiblezcomponentzitzmayzrequirezcorrection.zzButzposteriorztozanteriorzsli
des,wezdon’tzworryzaboutzthiszaszmuch.z
g. Evidencezofzocclusalzinterferencezinzprotrusivezmandibularzmovement.zz*Idealzcontactzwithzpr
otrusiveziszonzthezcuspids,zmanyztimeszthiszoccurszonzanteriorzteeth,zthezpatientzmayzhavezmor
ezperiodontalzdiseasezthanzyouzanticipate.zPeriodontalzdiseasezusuallyzoccurszfirstzinzposteriorz
, andzthenzanteriorzwithzgeneralized.zextremezcontactszinzprotrusivezoutzonzthezcentralszandzlat
erals,zmorezperiodontalzbonezlosszthanzwouldzbezanticipatedzoccurs.z
h. Presencezofzexceptionallyzsteepzcuspalzinclines.z
*Canzbuildzthiszinzprosthodonticallyzandzintroducedztroublezfromzocclusionzandztherefore,zperi
ozproblems.
Openzcontacts,zspaces,zanteriorzflaringzallzhappenzaszpatientszagezandzthiszcanzalsozcausezperio
zproblems.zz
Teethzarezpositionedzwhereztheyzarezinzthezmouthzdueztozforceszofztheztongue,zlip,zandzbone.zz
Losszofzbonezmeanszthezlipzandztonguezmayznotzbezstrongzenoughztozholdztheztoothzinzthatzloc
ation.zz1zinz3zpatientszwithzperiodontalzdiseasezhavezanteriorzflaring.zzProtrusivezproblems.zCon
tactzonzanteriorsznotzsharedzwithzcuspids.zzFremitusziszmovementzonzfunction.
Movementzwhenzopenzbiteztogetherzexcursivezmovementztoothzmoveszevenzmore.
Fremituszseeztoothzmovezinzthezmouth
Toothzwithzcrownz=zprimezcandidatezforzfremitus;zhyperzocclusionz=zocclusalztraumazandzthiszt
oothztriedzmovingzoutzofztrauma.z
Onezcanzwatchzthezbonezlosszoverztimezdueztozhyperocclusionzthatzwaszdonezincorrectlyzprost
hetically.
Wearzfacetszmayzappearzonzcusps,zcentralszmayzbezsplintedzdueztozmobility.zzcuspidzremoveszf
orcezonzcentralszandzlaterals.zzRootzlengthzfarzlongerzthanzcuspids.
Fremituszonzprotrusivezmovement.zWantztozremovezitzifzpossible,zifzyouzseezthis.z
**NBDEzwhenziszthezfirstztimezyouzwouldzthinkzaboutzdoingzocclusalzadjustment?zzNonzsurgical
ztherapy,zafterzsurgery,zonzmaintenance,zbeforezsurgery,zatzreeval?zz
Beforezsurgeryziszthezanswer.zReevalziszthezmostzlikelyztimezyouzwouldzdozthezgrosszocclusalzad
justment.zDecreasezinzinflammationzatzthiszpointzinztimezfirstztimeztherezisztimeztozremovezgro
sszprematurities,canzdozduringzinitialzprep,zifztheyzarezreallyzbad,zbutzreevalziszthezfirstztimezyo
uzmightzsee
Whenzshouldzdefinitivezocclusalzadjustmentzshouldzbezdone?zzInitial,zreeval,zbeforezsurgery,zaf
terzsurgery,zorzatzmaintenance.
Answerz=zafterzsurgery,zbutzitzcanzalsozbezdonezatzmaintenance.zzMostzofztheztimezoneziszthinki
ngzaboutzdoingzanzocclusalzadjustmentzimmediatelyzafterzmaintenance.
Mobilityzofztoothziszthezsamezorzbetterzafterzsurgeryz–
zsurgeryzneverzmakeszmobilityzworse.zzBestzcasezwillzbezimprovedzmobilityzstatus,zworstzcasezis
ztheztoothzwillzhavezthezsamezmobility.
Grosszprematurityz=zprematurityzthatzoccurszinzcentriczocclusion,zthezfirstzpointzofzthezzinitialzc
ontactziszinzCOzonzazmaxillaryzbicuspid.zzProsthodontistzsayszfirstzcontactziszinzCRzonzsecondzmol
ars
C. Histopathologyzofztraumazfromzocclusionz(compressionzside)
a. zCompressionzofzPDLzfiberszwithzinitialzdecreasezinzwidthzofzPDLzspace
b. LosszofzPDLzfiberzorientation
c. RupturezofzcapillarieszandzhemorrhagezintozPDLzperivascularzspaces
d. ResorptionzofzalveolarzbonezproperzfollowedzbyzwideningzofzPDLzspace
e. Ifzsevere,zrootzresorptionzmayzoccur
?*incidencezofzrootzresorptionzinzorthozcasesz16-
20%zofztheztimezthereziszrootzresorption.zzExcessivezforcezcauseszrootzresorptionzduringzortho.z
D. Histopathologyzofztraumazfromzocclusionz(tensionzside)
a. zTensionz(stretchingzofzfiberszwithzinitialzincreasezinzPDLzspace)zMovingztheztoothzawayzstretchz
toozmuch.z
b. RupturezofzPDLzfiberzbundles
, c. CompressionzofzPDLzcapillarieszandzhemorrhagezintozPDLzperivascularzspaceszconstrictszthezc
apillarieszandzcompromiseszvascularizationztozthezarea.zz
d. AppositionzofznewzalveolarzbonezproperzfollowedzbyzazdecreasezinzPDLzspace.zz*Mayzbuildzbon
ezonztheztensionzsidezandzlosezbonezonzthezcompressionzside.z
e. Ifzsevere,zcementalztearingzmayzoccurz*ifzthezcementalztearingzoccurs,zitztakeszsomeztimezforzt
hezbodyztozresorbzcementumzinzthezpdlzspace.z
*Thinkzofzorthozmovement,zifzaztoothziszmovedztozquicklyzinzorthodontics,zitzwillzresultzinzprobl
ems.z
Mayzgetzazmoatzlikezdefectzsurroundingztheztooth,zthiszmayzbezpathoneumoniczfromztraumazfr
omzocclusion.
Animalzmodel,zwithzrubberzdamzinzmesialzdistalzandzthenzonezotherzpoint,zcanzproducezocclus
alztraumazandzdefectszinzthezbonezratherzquicklyzinzazmonkeyzorzdogz(poorzpuppies)
V. OcclusalzHyperfunction
A. Resultszfromzslightzincreasezinzocclusalzforce
B. Consideredztozbezazphysiologiczadaptationzandznotzazpathologiczentityz**mostzcommonlyzoccurszin
zazclasszIIzrestorationthatziszaccidentallyzleftzhigh.
ClinicalzSymptomszofzocclusalzhyperfunction
Manyzofzthezsamezclinicalzsymptomszarezassociatedzwithztraumazfromzocclusionz–
zbutzalwayszthezfollowing
a. IncreasedzwidthzofzPDL
b. Increasedzwidthzandzdensityzofzthezradiographiczlaminazdura
c. Slightzincreasezinztoothzmobilityzwhichzmayzbezundetectable.z
d. Radiographiczevidence
VI. OcclusalzHypofunction
A. Azmildzweakeningzofztheztoothzsupportingzstructureszdueztozazlackzofzphysiologiczstimulation
B. Consideredztozbezazphysiologiczadaptationzandznotzazpathologiczentity
C. Canzonlyzbezdiagnosedzonzbasiszofzdentalzhistory
Histopathologyzofzocclusalzhypofuntion
a. DecreasezinznumberzofzPDLzfiberzbundles
b. Decreasedzphysiologiczturnoverzandzremodelingzofzalveolarzbone
c. NarrowingzofzPDLzspace.z
d. ***TQ:zNozchangezinztoothzmobilityzoccurszwithzhypofunction!!!!
VII. DisusezAtrophy
A. zTotalzremovalzofzocclusalzforceszresultingzinzazlackzofzthezlevelzofzphysiologiczstimulationzrequiredzt
ozmaintainznormalzformzandzfunction.z
PhysiologiczadapatationzandzNOTzconsideredzpathologic
a. zClinicalzsymptomszofzdisusezatrophy
(1) RadiographiczevidencezofzdecreasedzwidthzofzPDLzspace
(2) Increasedztoothzmobilityziszalwayszpresentz(?)
(3) Absencezofzocclusalzantagonist
b. Histopathologyzofzdisusezatrophy
(1) LosszofzorientationzofzthezprinciplezfiberzbundleszofzthezPDL
(2) NarrowedzPDLzwidth
(3) Significantzdecreasezinznumberzofzbonyztrabeculae,zi.e.,zlocalizedzosteoporosis.
VIII. Traumazfromzocclusionzinzthezabsencezofzinflammationzdoesznotzcause
A. Gingivitis******TQ
B. Periodontitis******TQ
C. Pocketzformation******TQ
