OralandMaxillofacial

MedicalImaging(1)

X-rayHistoryX-raysdiscoveredonNov.8,1895,byWilhelmConradRoentgenDr.OttoWalkhofftookfirstdentalradiograph;25-minuteexposureDr.C.EdmundKellstookthefirstintraoralradiographinearly189600Earlyx-raymachine.Arrowpointsto“l(fā)ive”electricalwire.ClinicalExam+RadiographsDiagnosisTreatment

00BitewingRadiograph(X-rayFilm,“X-ray”)PeriapicalRadiograph0PanoramicRadiograph0CephalometricRadiograph0TMJRadiographX-rayProduction00Atom(electricallyneutral)AtomicNumber(Z)=#ofprotonsK-shellL-shellprotonsneutronselectronsM-shell0Atom(electricallyneutral)AtomicNumber(Z)=#ofprotonsK-shellL-shellprotonsneutronselectronsM-shell0Atom(electricallyneutral)AtomicNumber(Z)=#ofprotonsK-shellL-shellprotonsneutronselectronsM-shellAttractionbetweenprotonsandelectronsElectrostaticForce0CentrifugalForcePullselectronsawayfromnucleus0Balancebetweenelectrostaticforceandcentrifugalforcekeepselectronsinorbitaroundnucleus0EFCFTheamountofenergyrequiredtoremoveanelectronfromitsorbit

(=electrostaticforce).Dependsonatomicnumber(Z)(#ofprotons).BindingEnergy0Themovementofenergythroughspaceasacombinationofelectricandmagneticfields

ElectromagneticRadiationTravelatthespeedoflight(3x108meters/second)(186,000miles/second)0ElectromagneticRadiationX-rayGammarayMicrowavesVisiblelightTVwavesRadiowaves0WavelengthxFrequency=SpeedoflightFWW0ElectromagneticSpectrumradiotvvisiblelightx-raysgammarayscosmicrays0ENERGYAbilitytopenetrateShorterwavelength,higherenergyHigherfrequency,higherenergy0ABC0Highestenergy?HighestenergyShortestwavelengthHighestfrequencyX-rayCharacteristics0TravelinstraightlineCannotbefocusedtoapointDifferentiallyabsorbedCausefluorescenceHarmfultolivingtissueX-rayCharacteristics0HighenergywavesNomassNocharge(neutral)TravelatspeedoflightInvisibleX-rayMachine

TubeheadSupportarmsControlpanel0PID,BID(cone)PID=positionindicatingdeviceBID=beamindicatingdeviceX-rayTubehead0degreestubeheadcontrolpanelsupportarms0tubeheadsupportarmscontrolpanel0exposuretimeadjustmentControlPanel

ExposureTime

70kVp7mA0ControlPanel

0mAcontrolkVpcontrolexposuretimekVpreadoutControlPanel(50-100)(10-15)(3impulses-5minutes)0X-rayTube0(molybdenum)(tungsten)CathodeFocusingcupFilament00x-sectionoffilament

hotfilamentThehotterthefilamentgets,thegreaterthenumberofelectronsthatarereleased.

electrons

ThermionicEmissionReleaseofelectronsfromhotfilamentwhencurrentflowsafterdepressingexposureswitchAnodeDentalx-raymachineshavestationaryanode0Copperstem

Targetsideviewfrontview

TargetMedicalRadiographyElectronbeamstrikestargetinthisareaonlyAnode(blueedgeistungsten)Filament/FocusingCup0Tungsten

Highatomicnumber(Z=74)

Transfersheatreadily

Highmeltingpoint(3422oC)Canbedrawnintofinewire(FilamentandTarget)0X-rayTubeComponentsberylliumwindow0TargetBerylliumWindowFocusingcupX-rayTube0Thesmallerthefocalspot(target),thesharpertheimage(teeth)willbe.Duringx-rayproduction,alotofheatisgenerated.Ifthetargetistoosmall,itwilloverheatandburnup.0LineFocusPrincipleLineFocusPrincipleApparent(effective)focalspotsizeActualfocalspotsizeTargetCathode(-)Anode(+)PID0LineFocusPrincipleApparent(effective)focalspotsize(lookingattargetsurfacethroughPID)Actualfocalspotsize(lookingperpendiculartothetargetsurface)0PIDX-rayMachineComponentsControlPanel

X-rayTubehead110,220lineTimerExposureswitchmAselectorkVpselectorAutotransformerStep-downtransformerStep-uptransformerX-rayTubeWiresOil0+110,220-110,2200positivenegative0DirectCurrent(ConstantPotential):800cycles/sec.

60-cycleAlternatingCurrentTimer0NumberofImpulses60=Seconds30impulses/60=0.5second15impulses/60=0.25second1/60060impulses/60=1.0secondYoucannotoverexposebyholdingtheexposureswitchdowntoolong!Allowscurrenttoflowtocompletehighandlowvoltagecircuits.ExposureSwitch0IndicatorlightandsoundmilliAmpere(mA)selector0mAsettingFilamentcurrentStep-DownTransformer110volt3–5voltsFilamentCircuit0Step-DownTransformerPrimarySecondary0110voltscurrentflow3-5voltscurrentflowkiloVoltpeak(kVp)selector0kVpcontrolkVpreadoutAutotransformerControlsvoltagebetweenanodeandcathodeRegulatedbykVpselector(Similartoarheostat)0110V65VcurrentflowAutotransformer080V65-90V65,000-90,000V(65kVp-90kVp)kVp=kiloVoltagepeakStep-UpTransformer0Step-UpTransformerPrimarySecondary0110voltscurrentflow65,000to90,000voltscurrentflow10-MINUTEBREAK0exposurebuttonoilfilterfilament0X-rayMachineComponentsfilament0110volts3-5volts65,000to90,000volts65-90volts<110voltskVp03X-rayProductionX-rayProductionBremmstrahlungCharacteristic0X-raysproducedwhenhigh-speedelectronsfromthefilamentaresloweddownastheypasscloseto,orstrike,thenucleiofthetargetatomsBremsstrahlungRadiation

(Brakingradiation,generalradiation)0BremsstrahlungX-rayProduction+0High-speedelectronfromfilamententerstungstenatomElectronsloweddownbypositivechargeofnucelus;energyreleasedinformofx-rayElectroncontinuesontootheratomsuntilallofitsenergyislostBremsstrahlungX-rayProductionMaximumenergy0High-speedelectronfromfilamententerstungstenatomandstrikesnucleus,losingallitsenergyanddisappearingThex-rayproducedhasenergyequaltotheenergyofthehigh-speedelectron;thisisthemaximumenergypossible+Theenergyofthehigh-speedelectronfromthefilamentmustbehigherthanthebindingenergyofthetargetelectronwithwhichitinteractsinordertoejectthetargetelectronX-rayshaveenergiescharacteristicofthetargetmaterial(energy=differencebetweenbindingenergiesoftargetelectronsinvolved,e.g.,K&L,K&M,etc.)CharacteristicRadiation0K-shellbindingenergy=70keVL-shellbindingenergy=11keVM-shellbindingenergy=3keVTungsten0Atomicnumber=74CharacteristicX-rayProductionLKMHigh-speedelectronwithatleast70keVofenergy(mustbemorethanthebindingenergyofk-shellTungstenatom)strikeselectronintheKshellEjectedelectronleavesatomRecoilelectron(withverylittleenergy)exitsatom0vacancyCharacteristicX-rayProductionKLMOuter-shellelectrondropsintovacantspot0X-raywith59keVofenergyproduced.70(bindingenergyofK-shellelectron)minus11(bindingenergyofL-shellelectron)=59.X-rayenergy(keV)characteristicx-rays(59&67keV)#ofx-raysX-raySpectrum(variablex-rayenergies)0Bremsstrahlungx-raysaverageenergyofx-raybeamX-raySpectrumresultsfrom:Varyingelectron/nucleusdistancesMultipleelectroninteractionsVaryingvoltage(AC)0Electroninteractionswithtargetatoms

1%producex-rays99%produceheatTheexcessheatiscontrolledbyhighmeltingpointoftungsten,conductivepropertiesofcoppersleeve,andcoolingfromoilsurroundingx-raytube0X-rayBeamModifiers0ExposureFactorskVpmAExposuretime0Incorrectexposurefactors(toomanyx-raysortoomuchenergy;filmtoodark)CorrectexposurefactorsIncorrectexposurefactors(notenoughx-raysorenergytoolow;filmtoolight)0kVp(kiloVoltpeak)0X-rayEnergy(keV)NumberofX-rays709090kVp70kVpmaximumenergyaverageenergy

Higheraverageenergy

ofx-rays

Greatermaximumenergy

x-rays

More

x-raysIncreasingkVpresultsin:0mA(milliamperes)0X-rayEnergy(keV)NumberofX-rays7010mA5mAmaximumenergyaverageenergy(nochange)(nochange)Exposuretime0X-rayEnergy(keV)NumberofX-rays7010impulses5impulsesmaximumenergyaverageenergy(nochange)(nochange)Increasing

mA

orExposureTime

resultsin:Anincreaseinthenumberofx-raysproducedNochangeintheenergyofthex-raybeam0

mAsormAimilliamperes(mA)xseconds(s)milliamperes(mA)ximpulses(i)

60impulses=1second10mAx.5seconds=5mAs20mAx.25seconds=5mAsmAi=60xmAs0

ConstantpatientsizeProperkVp,mA,exposuretime(e.t.)IncreasemA;nochangeinkVp,e.t.Decreasee.t.;nochangeinkVp,mAIncreasekVp;nochangeinmA,e.t.DoublemA,halvee.t.;nochangeinkVpACBBACAB0FiltrationTheprocessofremovinglow-energyx-raysfromthex-raybeam0InherentGlasswindowofx-raytubeAddedAluminumfilter(s)Total70kVp1.5mm2.5mmTotalFiltrationOil/Metalbarrier0filterPIDThefilterisusuallylocatedintheendofthePIDwhichattachestothetubehead.0CollimationRegulatesthesizeand/orshapeofthex-raybeamareacovered(lesspatientexposure)scatterradiation0primaryx-rayscatteredx-rayScatterRadiation0Collimator0YouarelookingupthroughthePIDatthecollimator,whichisacircularleadwasherwithacircularcutoutinthemiddle.Thiswillproducearoundx-raybeam.Thelightgrayareainthecenterisanaluminumfilter,whichisplacedonthetubeheadsideofthePID.collimatedbeamcollimator

target(x-raysource)frontviewssideview0Collimation2.75inches(7cm)=maximumdiameterofcircularbeamormaximumlengthoflongsideofrectangularbeamatendofPID.6cmround

film(4.5cmlong)entranceentranceexitexit6cm7cm7cmroundIfyouswitchfroma7cmroundPIDtoa6cmroundPID,thepatientreceives25%lessradiation.Rectangularcollimationresultsin55%lessradiationwhencomparedto7cmroundPID.0QualityQuantityaverageenergynumberofx-rays0(10)(20)Qualityvs.QuantitykVpmATimeFiltrationNochangeNochange0Half-ValueLayerIndicatesthequality(energy)ofthex-raybeamThethicknessofaluminumneededtoreducethebeamenergybyone-half2.5-70kVp+;1.5<70kVp0InverseSquareLawTheintensityofradiationvariesinverselyasthesquareofthetarget-filmdistance*target=source,focalspot,focus*00

TrytoappearconfidentExplainwhat/whyAnswerquestionsNounnecessaryinformationAnteriorfilmsfirst

EmpathizeWorkquicklybutefficientlyComplimentpatientPatientManagement

GeneralGuidelinesSpecialSituationsPatientManagementGaggingreducedby:

Properpatientmanagement(filmorder,positivestatements)DistractorsSaltontongueBreatherapidlythroughnoseFlavoringfilmsTopicalanesthetic

ChildrenKeepfilmstoaminimum(BW’s+Occl,PA’s,Pan)ExplainprocedureBefirmbutnon-threateningCompliment

AnatomyThirdmolarsMaxillarycuspidToriSpacelimitationsTongue-tiedThirdmolarsPanbestModifiedPAOKMaxillaryCuspidParalleling0Filmcan’tbeplacedfarenoughintothemouthdiagonalplacement(narrowarch)BisectingpalataltorusmandibulartorusToriPlacefilmontheoppositesideofpalataltorus(awayfromteethbeingradiographed)

Placefilmbetweentorusandtongue,makingsureitdoesn’trestontopoftorus

SpaceLimitationsShallowpalateShallowfloorofmouth

Usebisectingangletechnique

Tongue-tied(ankyloglossia)UsebisectingangletechniqueMayneedtousetongue-bladetosupportfilm(tapefilmtotongue-blade;placeontopoftongue)Usingthetonguebladetosupportthefilmforankyloglossialingualfrenum

portionoftonguesuperimposedoverroots

Trismus(prolongedspasmofjawmuscles;minimalopening)Pan(best)OcclusalPeriapical/hemostatUsingperiapicalfilmwithhemostatforpatientwithtrismusClaspingfilmwithhemostat,insertfilminmouthwithfilmparalleltofloor(horizontal)Oncethefilmhasclearedtheincisors,rotatethefilmtoaverticalpositioninmaxillaormandible.Edentulous

Pan(best)#4occlusal

HandicappedFilmholderAssistancefromrelative/friend;protectwithleadapron

HepatitisHIVUniversalprecautionsPregnancy

…thefetalexposureisonlyabout1microGrayforafull-mouthseries.Accordingly,theguidelinescanbeusedwithpregnantpatientsjustaswithotherpatients.Pregnancy

Theunbornchildisverysensitivetoionizingradiation.Limitradiographicexaminationduringpregnancytocaseswithaspecificdiagnosticindication.Postponeelectiveproceduresuntiltheterminationofthepregnancy.

DentalHistoryClinicalexamProfessionaljudgementSelectioncriteriaOrderingFilms0DentalHistorySymptomaticteeth,mostrecentfilms,frequencyofvisits,attitudeClinicalExamConditionofteeth(caries,restorations,displacement,mobility,etc.),#teethpresent/abutmentteeth,teethremovedfororthoProfessionalJudgementEducation,experience,finances

HistoricalFindingsPain,swelling,bleeding,mobilityTraumaEndoImplantsFamilyhistoryTMJpain

SelectionCriteriaLargecaries/restorationsPeriodontaldisease/mobility/bleedingEvidenceoftrauma/swelling/fistulaPotentialabutmentteethUnusualtoothappearance/positionThirdmolarsFacialasymmetrySelectionCriteriaClinicalFindingsFilmorder:4bitewings,Pan0Symptomatic:NoneFractured:NoneLargecaries:NoneLargerest.:#30Missing:#’s5,12,21,28(patientsays3rdshavenotbeenremoved)Gingiva:MildgingivitisLargerestorationFilmorder:2BW,1PA,Pan0Symptomatic:#8Fractured:#8Largecaries:NoneLargerest.:NoneMissing:#’s1,16,20,32Gingiva:HealthySmallrestorationFractureFilmorder:4BW,2PA,Pan0Symptomatic:#’s3,10Fractured:NoneLargecaries:#’s15,32Largerest.:#’s3,6,8,12,13,17,21,23,24,25,26,28,29,30Missing:#’s1,2,7,14,18Gingiva:Generalredness,inflammationbridgeSmallrestorationCrownsLargerestorationLargecariesbridgeFilmorder:4BW,15PA(AFM)00Filmorder:1PA,4BWFilmorder:3PA,2BW0Filmorder:4BW,15PA(AFM)0Filmorder:AFMorPan0

Thefrequencyoftakingfilmsisbasedonthefollowingfactors:1.Patient’soralhygiene2.Cariesactivity3.Dentalhistory4.Reliabilityofpatient5.ADAGuidelines0ADAGuidelinesFull-mouthSeries1-5yearsBitewings6months-3yearsPanoramic1-5yearsRadiobiologyTheresponseoflivingsystemstoionizingradiationIonizationTheprocessofremovinganelectronfromanelectricallyneutralatomtoproduceanion.Anionisanatomorsubatomicparticlewithapositiveornegativecharge.Ionization0negativeionpositiveionIonizingRadiationElectromagneticX-rays,gammaraysParticulateAlphaparticles,electronsAttenuationReductionofx-raybeamintensity(thatreachesfilm)byinteractionwithmatter.1.Coherentscattering2.Comptonscattering3.Photoelectricabsorption

9%ofx-raysnotattenuatedCoherentScatteringLow-energyx-rayinteractswithouter-shellelectronandcausesittovibratebriefly.Scatteredx-rayofsameenergyasprimaryx-rayisthenemitted,goinginadifferentdirectionthanprimaryx-ray.Electronnotejectedfromatom.(Noionization).0CoherentScattering0

ComptonScatteringOutershellelectronejected(Ionization)ScatterradiationresultsOccurs62%ofthetime30%ofscatterexitshead

0recoilelectronscatteredx-rayComptonScattering0primaryx-rayTheprimaryx-raystrikesanouter-shellelectron,knockingitoutofitsorbit(ionization).Theprimaryx-raylosessomeofitsenergyandcontinuesinadifferentdirectionasascatteredx-ray.Inner-shellelectronejected(Ionization)CompleteabsorptionOccurs30%ofthetimePhotoelectricAbsorption0photoelectronprimaryx-rayPhotoelectricAbsorption0Theprimaryx-raystrikesaninner-shellelectron,knockingitoutofitsorbit(ionization).Thex-raylosesallofitsenergyanddisappears.Thereisnoscatter.Dose-ResponseCurvesthresholdlinearnon-linearnon-thresholdResponseDoseLinear:theresponseisdirectlyrelatedtothedose.Non-linear:theresponseisnotproportionatetothedose.Threshold:thedoseatwhicheffectsareproduced;belowthisdose,therearenoobviouseffects.Non-threshold:anydoseproducesaresponse.Stochasticeffect:occursbychance,usuallywithoutathresholdlevelofdose.Theprobabilityofastochasticeffectisincreasedwithincreasingdoses,buttheseverityoftheresponseisnotproportionaltothedose.Geneticmutationsandcancerarethetwomainstochasticeffects.Deterministiceffect:healtheffectsthatincreaseinseveritywithincreasingdoseaboveathresholdlevel.Usuallyassociatedwitharelativelyhighdosedeliveredoverashortperiodoftime.Skinerythema(reddening)andcataractformationfromradiationaretwoexamplesofdeterministiceffects.0CriticalMolecule(Target)DNA00

RadicalAtomormoleculethathasanunpairedelectroninthevalenceshell,makingithighlyreactive0MutationsCelldeathSublethalinjuryBiologicEffects0DNAaltered;cellfunctionalteredordevelopmentchanged.Itisunclearwhichcriticallesion/sinDNAmayleadtocancer.MutationNormalMutation0September25,2006LossofcapacityformitosisCellDeath0CellularRepairDamagetobiologicmolecules(single-strandbreakofDNA)2.Removalofdamagedsectionbycellenzymes3.Placementofnewmaterialbyothercellenzymes0

CellCycleMoredamageresultswhencellirradiatedduringtheG1/earlySportionofcellcycle0ManymitosesUndifferentiatedLymphocytes,germcells,basalcellsofskinandmucosa,erythroblastsRadiosensitiveCells0FewmitosesWelldifferentiatedNerve,muscle,boneRadioresistantCells0RadiationEffectsInfluencedby:

TotaldoseDoserateTotalareacoveredTypeoftissueAge0

LinearEnergyTransfer(LET)Therateoflossofenergyfromradiationasitmovesthroughtissue.ParticulateradiationhashigherLETthanx-rays.0Oxygenhelpsproduceperoxylfreeradical,themostdamagingOxygenEffectSurvivalDose0SomaticCellDamage

(affectsindividual)

vs.GeneticCellDamage

(affectsoffspring)0

HORMESISLowdosesofradiationarebeneficialStimulatesourantimutagenicDNAdamagecontrolsystem(oxidativefreeradicalscausemutations;theseareminimizedbypreventiveantioxidants,repairingenzymes,celldeathandimmunesystem)Dr.MyronPollycove,U.S.NuclearReg.Comm.010-MINUTEBREAK0DOSIMETRY0Whole-bodyRadiation

vs.Specific-areaRadiation0UnitsofRadiationMeasurementRoentgen(R)CoulombsperkilogramradGrayremSievert0

Roentgen(R)RadiationExposure(inair)SIunit=coulomb/kg0

rad

radiationabsorbeddose(intissue)SIunit=Gray(Gy)=100rads1cGy=1rad0

remroentgenequivalentmanradxQF=remcompareseffectsofdifferenttypesofradiationSIunit=Sievert(Sv)=100rems1cSv=1rem01R=1rad=1rem1Gray=1Sievert1000mrem=1remAnnualRadiationExposure

360mrem(3.6mSv)/yearRadon200mrem(55%)Cosmic27mrem(8%)Rocks/soil28mrem(8%)Internal40mrem(11%)Medicalx-rays39mrem(11%)Nuclearmedicine14mrem(4%)Consumerproducts10mrem(3%)Othersources<1mrem(1%)Natural(Background)

Radiation

3000

μSv

External(16%)

CosmicTerrestrialInternal(Food-11%)Radon(55%)CertainblacksandbeachesinBrazilproduceradiationlevelsashighas5mrem/hour.Thiswouldbeequivalenttogettingafullseriesofx-rayfilmseveryhour.SomeplantsinanotherareaofBrazilhaveabsorbedsomuchradiumthattheywillproduceanautoradiographwhenplacedonphotographicpaper.Medical

(11%)

(Dental-0.1%)NuclearMedicine(4%)ConsumerProducts

(3%)Artificial(Man-made)

Radiation

600

μSv

SurfaceExposurePeriapical/BW:100mrem(F-speed)250mrem(D-speed)Panoramic:500mremAFM:2rem(F-speed)LateralCeph:150mremChestFilm:20mrem1mrem=.001remor1000mrem=1remEffectiveDoseEquivalentAFM(round,F)60μSvAFM(rect.,F)27μSvPanoramic7μSvCeph220μSvChest80μSvNaturalRadiation3000μSvEquivalentBackgroundExposureAFM(round,F)5daysbkgrAFM(rect.,F)2daysbkgrPanorex(rare)10hoursbkgrAdult:50mSv/yrNCRP&OhioMinor:5mSv/yrPregnant:5mSv/yr5mSv/yr(0.5rem)NCRP1mSv/yr(0.1rem)(Ohio)RadiationWorkers(Over18)GeneralPublic

MPDMaximum

PermissibleDoseOne-in-onemillionchanceofdying:

AFMSmoking1cigaretteDrinking30cansofdietsodaRidingabicycle10milesDrivingacar300milesFlying1000milesProfessionalJudgmentSelectionCriteriaEquipmentReliabilityLeakageradiationTimeraccuracyX-rayproductionStateinspectionStateRequirementsRadiationSafetyOfficer(anyofficeemployee)NoticetoEmployees(mustbeposted)SafeOperatingProcedures(manual)InstructionofIndividualsConstantPotential(800cycles/sec.)60-cycleAlternatingCurrentInherentGlasswindowofx-raytubeAddedAluminumfilter(s)Total70kVp1.5mm2.5mmTotalFiltrationOil/Metalbarrier0CollimationFocusFilmDistance

IntraoralFilmSpeedD-speed(Ultraspeed)F-speed(Insight)

Largersilverhalidecrystals60%lessradiationthanDScreenSpeedFastlessexposurelessdetailMediumcompromisebetweenspeedanddetailSlow(Detail)moredetailmoreexposureLeadApron/ThyroidCollarPsychologyProtectionTakingfilms-ProperfilmplacementandexposureTechniqueProcessingCorrecttime,temperaturePropersafelightingLight-tightdarkroom0X-rayProtectionfortheOperatorDonotholdfilmforpatientUtilizebarriersifavailable;drywalladequate.MustbeabletoobservepatientFollowpositionanddistanceruleSeatpatientRaiseorlowerchairasneededAdjustheadrestPlaceleadapron,thyroidcollarPatientPreparation:ParallelingTechniqueFilm/tooth/ringallparallelX-raybeamperpendiculartotooth/filmX-raybeamParallelingTechniqueADVANTAGES1.Betterdimensionalaccuracy2.Beamalignmentsimplified4.Headpositionnotcritical3.Easiertostandardizefilms(comparedtoBisectingAngletechnique)LongaxisofthetoothparallelwithlongaxisofthefilmParallelingTechniqueDISADVANTAGES1.Maybeuncomfortable2.Limitedbyanatomy(comparedtoBisectingAngletechnique)correctincorrect0Thefilmmaybetippedupto20degreesbeyondparallel0Filmpositionedawayfromteethtoachieveparallelism.Becausethepalateandfloorofthemouthareshallowerasyouapproachthelingualoftheteeth,thefilmoftencannotbepositionedproperlyclosetotheteeth.0Becausethefilmisfartherfromtheteeth,therewillbeincreasedmagnificationanddecreasedsharpness.Tocompensateforthis,thetarget-filmdistanceshouldbeincreased.LongPID(cone)XCP

ShortPIDRecessedtarget

MediumPIDRecessedtargetBestOKOKParallelingTechniqueHeadPosition#1#2#2Adultfull-mouthseries,ParallelingTechniqueRL#2#2#1AdultsanteriorposteriorChildren(smallmouths)#0#0anteriorposteriorUse#1(anterior)or#2(posterior)ifchild’smouthislargeenoughtoaccommodatethemRinnXCPParallelingInstrumentsANTERIORPOSTERIORWhenyoulookthroughthering,thefilm(all-whiteside)shouldbecenteredintheopening.frontbackoppositesidetowardtubeAll-whitesideoffilmfacesteeth/ringAnteriorPeriapical(in-the-slot)FESpeed1-FilmlongaxisverticalINSIGHTDentalFilmKodakPosteriorPeriapical(in-the-slot)longaxishorizontal

OPPOSITESIDETOWARDTUBE

KODAKINSIGHT1-FILMFEThefilmshouldbeequidistantfromtheteethinananterior-posteriordirectioncorrect

incorrectresultsinoverlapPosteriorFilmsTheteethbeingradiographedmustbeincontactwithbiteblock.Makesurepatientdoesn’tjustcloselipstightaroundbiteblock.correctincorrectCottonrollsmaybeusedinanyareaofthemouthtohelpsupportthebiteblock,especiallyifanedentulousregionopposestheteethbeingradiographed.Oftenmakesitmorecomfortableforthepatient.Thecottonrollshouldbeplacedagainstthearchoppositetheonebeingradiographed.Whilesupportingthebarwiththefingersofonehand,slidetheringdownclosetothefacewiththeotherhand.0Makesureheadissupportedbyheadrestbeforeexposingfilms.ThePIDshouldbeequidistantfromtheringandwithin?”oftheringIncorrectIncorrectMaxillaryCentral-lateralFilmcenteredoncontactbetweencentralandlateralincisors.Makesuremesialedgeoffilmcrossesmidlineslightly.Filmshouldbeplacedwellbackinthemouth,awayfromtheteeth.MaxillaryCentral-lateralIf#2sizefilmisused,thefilmiscenteredonthemidline.Onlyonefilmisusedtoimagealltheincisors.MaxillaryCanineFilmcenteredoncanine.Filmshouldbeplacedwellbackinthemouth,awayfromtheteeth.MaxillaryCanineNoteoverlapbetweencanineandfirstpremolar.Usuallynotavoidableinmaxillarycanineregionusingparallelingtechnique.MaxillaryPremolarFilmpositionedsothatanterioredgeisatleastinthemiddleofthecanine,ormoreanteriorifpossible.Approximatelycenteredon2ndpremolar.Topedgeoff