PAGEPAGE3UnitSeventeenNote:PleasepayattentiontotheunderlinedwordsorphrasesNote:Pleasepayattentiontotheunderlinedwordsorphrasesinadditiontothewordsinblue.ORALDISEASES:PREVENTIONISBETTERTHANCUREOraldiseasessuchascariesandperiodontaldisease(infectionsofthegumsandofthetoothsupporttissues)areamongthemostwidespreaddiseasesintheworld.Theyaffectallpopulationstovaryingdegrees.Dentalcariesintheworld:asituationofcontrastTheindexformeasuringtheextenttowhichapopulationisaffectedbycariesisthemeanDMFT,whichinagroupofindividualscountstheaveragenumberofteeththatareDecayed,Missing(onaccountofcaries)andFilled.Itisasimple,rapidanduniversallyapplicablemeasurementthathasbeenwidelyusedforseveraldecades.Wehavedrawnupascaleforseverityofinvolvementatvariouskeyages:12,35-44,65andover.Atage12the5levelscalevariesfrom0.0to6.6ormore:aDMFTbetween0.0and1.1isconsideredverylow,afigureof6.6ormoreisveryhigh,whileamoderateDMFTisbetween2.7and4.4decayed.AnycountryundertakingananalysisofitsoralhealthsituationcancomparetheresultswithWHO'sworldwideobjective:bytheyear2000nomorethanthreedecayed,missingandfilledteethatage12.Byrepeatingtheanalysisatregularintervals(WHOrecommendsanevaluationeveryfiveyears)itispossibletomonitorthetrendincariesprevalence,toestimatetheneedsforcareandpreventionandtoadjustpersonneltrainingandservicesaccordingly.ItshouldbepointedoutthatthesimplifiedoralhealthsurveymethoddevelopedbyWHOisreliable,veryinexpensive,canbeusedanywhereandprovidescomparabledatabothintherichestcountriesandinthepoorest.WHO'sOralHealthUnitprovidestechnicalsupportforepidemiologicalsurveysandprocessescountrydatafreeofchargeonrequest.TheinformationcollectedisstoredintheGlobalOralDataBank(GODB)systeminthecatalogueofUnitedNationsdatabanks,wherebyitispossibletofollowtheworldwidetrend.Everyyearsince1969,WHOhascompiledaworldmapofcariesatage12.In1969theoverallpictureshowedsharpcontrasts:theDMFTwasveryhigh,highoratleastmoderate(between2.7and4.4)intheindustrializedcountries,whereasitwasgenerallyverylow,lowandoccasionallymoderateinthedevelopingcountries.Overthenexttwodecadestherewasadownwardmovementandsometimesaspectacularfallintheprevalenceofcariesinvirtuallyalltheindustrializedcountries.Inthedevelopingcountriesthegeneraltrendisforcariesprevalencetoincreaseexceptwherepreventionprogrammeshavebeensetup.Everyyearsince1980theWHOOralHealthUnithascalculatedthemeanglobalDMFTatage12,weightedforpopulation.Theresultinggraphsdisplaythetrendsindentalcariesintheindustrializedcountries,inthedevelopingcountriesandformankindasawhole.Thetrendinthemeansince1980justifiesmeasuredoptimismforthenext10years,althoughthesituationisstilldelicateinasmuchasasmallincreaseinveryhighlypopulatedcountriesisallthatisneededtotakethemeanabove3.****Whatistheexplanationforthespectaculardropincariesprevalenceinsomecountries?Howcanitbepreventedfromrisingagain?Howcantheworseningofthesituationinothercountriesbehalted?Thereplytothesethreequestionsisoneandthesame:prevention,morepreventionandstillmoreprevention.Intheindustrializedcountriesthepromotionoforalhygiene,thewidespreaduseoffluoridetoothpaste,theintroductionoffluorideintodrinkingwaterorsaltinsomecountries,adviceonnutrition(nosweetsbetweenmealsandetc.)arethefactorsbehindanunprecedentedpublichealthsuccessstory!Wherevercommunitypreventionprogrammesaresetup,cariesstopadvancing.Forexample,thishashappenedinBulgaria,FrenchPolynesiaandThailand.Apartfromthefluoridationofwater,saltandmilk,whichrequiresmoreadvancedtechnologyandsupervisedcentraladministration,allthemethodsoforalhygienemakeuseofsimpletechniques,costlittleandareperfectlysuitedtoimplementationatprimaryhealthcarelevel.Asaresultoftheprogressmadeinthelast25years,thedevelopingcountriesnowhavetheknowledgeandmeansofpreventionthatwillenablethemtoavoidtheproblemstheindustrializedcountrieshavehadtoface,andindeedstillarefacingataveryhighprice!Inmostindustrializedcountriestheoralhealthservicesstillabsorbbetween5%and11%ofthenationalhealthbudget.Thereisnoreasonatalltocontinuedevotingsubstantialresourcestotreatingaconditionthatcanbepreventedbysimple,variedandinexpensivemeasures.Butthereneedstobethepoliticalwilltogiveprioritytoprevention.****Whataboutthe"periodontaldisease"?Towardstheendofthe1960smostdentalepidemiologistssharedtheviewthatperiodontaldiseases,unlikecaries,weremorecommoninthedevelopingcountriesthanintheindustrializedcountries.However,theavailabledatawereveryfragmentaryanddifficultorimpossibletocomparesincetherewerenofewerthanfivedifferentindicesincommonuse.Thisplethoraofmethodswascompoundedbythedifficultyofcollectingdatafromadults;aproblemthatislessseriousinthecaseofcaries,wherethekeyageis12years.Withthedefinitionofaperiodontalindex,whichveryquicklyachievedwideinternationalacceptance,theepidemiologyofperiodontaldiseaseshasmadegreatstrides.TheCPITN(CommunityPeriodontalIndexofTreatmentNeeds)wasproposedbyaWHOscientificgroupandrecommendedintheearly1980sbyajointworkinggroupfromWHOandtheFDI(InternationalDentalFederation).Thisindexrecordstheperiodontaldiseasesintermsoffourclinicalsigns:l.Bleedingfromthegum2.Presenceofcalculus3.Presenceofshallowperiodontalpockets4.PresenceofdeepperiodontalpocketsA"periodontalpocket"isconsideredtobepresentwhen'thegum,undertheeffectofinflammationand/orinfection,retracts,formsapocketandnolongeradherestothetooth.Theligamentsbecomeimpairedandthetoothbecomesincreasinglyloose.Tomeasureperiodontalstatus,themouthisdividedintosixpartsorsextants.Aspeciallydesignedprobeisusedtotestthecondition(l,2,3or4)ofthegumaroundthetoothselectedastheindextoothforeachsextant.Ifseveralclinicalsignsarepresentsimultaneously,themostsevereisselected.WHOhascompileddataonoverIOOsurveyscarriedoutintheagegroup35-44years.Thesedatashouldbetreatedwithcaution,sinceveryfewofthemprovideanationalestimate.Neverthelesstheyareofgreatinterestbecausetheyconsistentlyshowasimilarpatternoffrequencyandseverityofinvolvement,whichchallengessomegenerallyacceptedideasaboutthedistributionandtheetiologicalprocessofperiodontaldisease.Thedatashowthatthepercentageofpeoplewhohavedeeppocketsandthemeannumberofsextantsperpersonalsodisplayingdeeppocketsarelowtoverylow.Thismeansthatthesevereformsofperiodontaldisease,thoserequiringcomplicatedsurgeryarefarfromcommon.Moreover,thereseemstobenodifferenceinfrequencybetweenindustrializedcountriesanddevelopingcountriesforthesevereformsofperiodontaldisease.Ontheotherhand,theinitialforms(bleedingandcalculus)aremuchmoreprevalentinthedevelopingcountries.Inthelightofthesedataitmaybestatedthatgeneralizedperiodontaldestructionisrarein40-year-oldadults.Somepeopleshowsomesignsofsuchdestruction,butonlyalimitedpartoftheirdentitionisaffected.Itseemsthattheinitialforms(bleedingandcalculus)donotnecessarilyleadontotheadvancedstagesofthedisease,exceptincertainminoritygroups.Howcanthesediseasesbeprevented?Afterafewdaysofcarefulcleaningoftheteeth,thebleedingstopsinthevastmajorityofcasesandtheinflammation,thecauseofmuchdiscomfort,alsoregresses.Therearevariouspossiblepreventionpolicies:hygieneforthemostcommonandleastseriousforms;developmentofproductsthatactagainstthedestructivetypesofperiodontitis.Awholefieldofresearchtoprotecttheriskgroupsisopeningup.VOCABULARYl.gum,gingiva牙齦2.calculus,tartar牙結(jié)石3.Fooddebris食物殘?jiān)?.Dentalplaque牙菌斑5.index,indices指數(shù)，索引6.meanDMFT齲(牙)均7.D-Decayed齲8.M-Missing(onaccountofCaries)失9.F-Filled補(bǔ)10.Keyages(indexagegroups)指數(shù)年齡組11.oralhealthsituation口腔健康狀況12.regularintervals定期，間隔一定時(shí)間13.monitor監(jiān)測，監(jiān)督14.cariesprevalence患齲15.simplified簡化的16.reliable可靠的17.epidemiologicalsurvey流行病學(xué)調(diào)查18.preventiveprogromme預(yù)防項(xiàng)目(計(jì)劃)19.onrequest根據(jù)要求20.databank資料庫(數(shù)據(jù)瘁)21.compile(d)編制22.Sharpcontrast(s)鮮明對比23.downward向下的，下降的24.upward向上的，上升的25.spectacularfall引人注目的下降26.virtually事實(shí)上，實(shí)際上：27.weightedforpopulation加權(quán)人口28.Justify,justifies證明(認(rèn)為)……有道理，為·…．·提供依據(jù)29.optimism樂觀(主義)30.graph座標(biāo)圖，曲線圖31.worsening(使)惡化、變壞32.halt(ed)停止、止步，休息33.unprecedented空前的，無先例的34.supervised在監(jiān)督指導(dǎo)下的35.fluoridation氟化36.administration管理37.oralhygiene口腔(清洗)衛(wèi)生38.primaryhealthcare初級衛(wèi)生保健39.healthbudget衛(wèi)生預(yù)算40.devote獻(xiàn)(身)，貢獻(xiàn)，專心致力于41.substances實(shí)質(zhì)的，有價(jià)值，有實(shí)力的42.priority重點(diǎn)，優(yōu)先43.inexpensivemeasures廉價(jià)措施44.share(d)分享，分擔(dān)45.periodontaldiseases牙周疾病46.fragmentary片斷的，殘缺不全的47.plethora過多(剩)48.periodontalindex牙周指數(shù)49.internationalacceptance國際承認(rèn)(接受)50.strides(s)邁進(jìn)，進(jìn)步51.CPITN(CommunityPeriodontalindexofTreatmentNeeds)社區(qū)牙周治療需要指數(shù)52.FDI(InternationalDentalFederation)國際牙科聯(lián)盟53.bleedinggum牙齦出血54.shallowperiodontalpockets淺牙周袋55.deepperiodontalpockets深牙周袋56.retract(s)退縮，萎縮57.adhere(s)附著，吸附58.ligament(s)韌帶59.impaired受損傷的60.loose(牙)松動(dòng)61.sextant(s)(牙周)區(qū)段62.speciallydesignedprobe專門設(shè)計(jì)的探針63.indextooth指數(shù)牙64.simultaneously同時(shí)，—齊65.caution小心、慎重66.similarpat