IntraoralRadiographic

OralandMaxillofacial

MedicalImagingSeatpatientRaiseorlowerchairasneededAdjustheadrestPlaceleadapron,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.Topedgeoffilmincenterofpalate.MaxillaryPremolarMaxillaryMolarFilmcenteredonsecondmolar.Topedgeoffilmincenterofpalate.MaxillaryMolarMandibularincisorFilmcenteredonmidline.Filmshouldbeplacedawayfromtheteethasmuchaspossible.0MandibularincisorLetpatientguidefilmintoplaceastheyclosetheirmouth00MandibularCanineFilmcenteredoncanine.Filmshouldbeplacedawayfromtheteethasmuchaspossible.0MandibularCanine00MandibularPremolarAnterioredgeoffilmispositionedatleastinthemiddleofthecanine,ormoreanteriorifpossible.Approximatelycenteredon2ndpremolar.Thefilmshouldbeplacedmoretowardthemiddleofthemouth,awayfromtheteeth.Thisisusuallythemostuncomfortablefilmtakenonapatientusingtheparallelingtechnique.0MandibularPremolar0MandibularMolarFilmcenteredonsecondmolar.Filmmaybeplacednexttotheteeth.MandibularMolartopedgeofPIDaboveringNormalalignmentmissesapicesSolution:IncreaseverticalRaisePIDForpatientswithlongroots:0

ParallelingTechnique

ERRORS0PoorfilmplacementPremolar-OKMolar-tooanteriorPatientnotbitingonbiteblockTippingTippingDoubleexposurePatientmovementOverlap(incorrecthorizontal)ExposurelevelsoverexposureunderexposureGlassesnotremovedGlassesUPDleftinmouthFilmbendingcausedbycrimpingfilmwheninsertingintoslotofbiteblock.10MINUTEBREAKBisectingAngleTechniqueBisectingAngleTechniqueADVANTAGES(comparedtoParallelingtechnique)MorecomfortableNoanatomicalrestrictionsFilmholdernotessentialBisectingAngleTechniqueDISADVANTAGES

ImagesdistortedHardertopositionbeamFilmlessstable(comparedtoBisectingAngletechnique)AnatomicalVariations

Shallowpalate/palataltorusShallow/tenderfloorofmouthShortlingualfrenumImpactedthirdmolars(headtippedback)MSPfloorFull-mouthseries,BisectingAngleTechnique(all#2filmsforadults)#2Adultsanteriorposterior#2Children#0#0anteriorposteriorIfthechild’smouthislargeenough,andthechildiscooperative,usea#2sizefilminsteadofthe#0.Snap-A-RayWhenusingfingerplacement,alwaysusethehandoppositetothesideofthemouthbeingradiographed.(e.g.,usetheleftindexfingerwhentakingtherightmaxillarypremolarfilm).Useeitherthumbforthemax.ormand.incisorfilm,thethumborindexfinger(oppositehand)forthecanines,andtheindexfinger(oppositehand)fortheposteriorfilms.PositioningtheX-rayBeamLongaxisofthetoothnotparallelwithlongaxisofthefilm.X-raybeamperpendiculartolinebisectingangleformedbyfilmandlongaxisoftooth.BisectingParalleling0Overlap(incorrecthorizontal)MaxillaryIncisorMaxillarycanineCaninehorizontalangulationMorelikelytoseeoverlap(above)whenusingtheBAinstrument,assumingyouuseproperhorizontalangulationw