专业英语 Unit 5教案学习资料

UnitFiveDIFFERENTIALDIAGNOSISOFMULTILOCULARRADIOLUCENCIES——ANATOMICPATTERNS,KERATOCYSTANDAMELOBLASTOMAMultilocularradiolucenciesareproducedbymultiple,adjacent,frequentlycoalescing,andoverlappingpathologiccompartmentsinbone.Theymayoccurinthemaxillabutarefoundmuchmorecommonlyinthemandible.AnatomicPatternsToprecludetheirbeingmistakenformultilocularlesions,twonormalradiolucentstructuresoftheperioralregionsandtheirradiographicvariationsarenotedanddescribedinthissection:themaxillarysinusandbonemarrowspaces.Themaxillarysinususuallyhasseveralcompartmentsthatprojectintothesurroundingmaxillaandzygomaandgivetheradiographicappearanceofseptadividingthesinusintolobes.Whenmanysuchlobesorcompartmentsarepresent,theresultantimagemaybeofsoupbubbles.Theanatomiclocationofthevariableextensionsofthesinusandtherelativemovementofadjacentstructuresonradiographstakenfromdifferentangles,coupledwiththeabsenceofsymptoms,areusuallysufficienttoidentifytheseareasaspouchesfromthemaxillaysinus.Bonemarrowspacesandtrabecularpatternsappearfrequentlyasmultilocularradiolucencies,especiallyinthemandible.Usuallywhenthesespacesandpatternsresemblepathologicmultilocularradiolucencies,acomparisonwiththepatternoftrabeculationintheremainderofthejawbonewillshowasimilarimagesotheexaminercanconcludewithreasonablecertaintythatthesuspicious-lookingregionisanormalvariation.OdontogenicKeratocyst(OKC)RadiographicallytheOKCcannotbedistinguishedfromotherintrabonycysts.Onoccasionitslumen,denselyfilledwithkeratin,willcausetheusualradiolucentcystlikeimagetohaveahazyappearance.Sometimesalsoitwillhavescallopedbordersandoftenoccurswithamultilocularappearance.AlthoughmultipleOKCsofthejawshavebeenreported,onlythebasalcellnevussyndromeaccompaniedsomeofthese.Occasionallythecystwillexpandthecorticalplatesandperforate;whenpalpated,itwilldemonstrateafirmerfluctuancethantheusualbonycystthathasperforatedthebonyplatesbecausethelumenoftheOKCisfilledwithkeratinhavingasomewhatdoughyconsistency.TheOKCdiffersfromotherbonycystsinshowingarelativelyhighrecurrencerate,reportedtovarybetween12%and51%.Someoftheselesionsrecurredaslongasl5yearsaftertheirinitialremoval.AmeloblastomaTheameloblastomaisanodontogenictumorusuallydescribedaslocallyinvasiveandtboughttoarisefromameloblasts.Itrepresentsapproximately11%ofodontogenictumors,themostcommonlvencounteredbenignneoplasm.Amultilocularcysticappearanceisbyfarthemostcommonlyseen"radiographicpictureofameloblastoma.Themarginofthelesionisdefinite,usuallycorticated,andirregular.Often,thereissmallcircularradiolucenciesprojectingfromthemainmasscalled"daughtercysts".Therearepronouncedcurvedradiopacitieswithintheradiolucentlesioncausingthemuitilocularappearance.Athinlayerofboneusuallycoverstheradiolucency,butwhenthelesionispresentedintheramusitmaybreakthroughtheanteriorsurface.Inmanyinstancesthelingualplateisaffectedmorereadilythanthebuccalplate.Infrequently,thereisseena"honeycomb"appearance,whichispresentmoreofteninthemaxillathanthemandible.VOCABULARYl.multilocular多房的2.radiolucencyX线透射区3.radiolucentX线透射的4.coalesce融合5.overlap重叠，交错6.compartment腔隙，房室7.perioral口周的8.variation变化，变异9.maxilla上颌骨10.mandible下颌骨11.zygoma颧骨12.septum(pl.septa)间隔，分隔13.sinus窦14.lobe叶15.pouch囊16.trabecular(骨)小梁的17.trabeculation(骨)小梁形成18.jawbone颌骨19.odontogenic牙源性的20.keratocyst角化囊肿21.intrabony骨内的22.lumen腔23.cystlike囊样的24.hazy模糊的25.scallop使成扇形26.nevus痣27.syndrome综合征28.expand使膨胀29.cortical皮质的30.corticate.Corticated有皮质的31.perforate穿孔32.palpate触诊33.fluctuance波动34.plate板35.keratin角蛋白36.doughy面团样的37.consistency,consistence硬度38.recurrence复发39.removal切除40.ameloblastoma成釉细胞瘤41.ameloblast成釉细胞42.invasive侵蚀