法醫人類學

ForensicAnthropology性別鑒定

[SexDetermination]

IntroductionSexualdimorphismTheImmatureSkeletonTheAdultSkeleton:Morphology

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Theskull

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Thepelvis

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OtherpostcranialindicatorsTheAdultSkeleton:MetricAnalysisParturitionScarsSummaryandConclusionsSexDeterminationC

Introduction

1.Assessmentofsexisoneofthemostvitaldeterminationstomakewhenitisnecessarytoestablishidentityfromskeletalremains.2.Unfortunately,thisisoftennotasimpleprocesssincemaleandfemaleattributesspanacontinuumofmorphologicconfigurationsandmetricmeasuresintheskeleton.Althoughsomebonesarebetterindicatorsthanothers,thereisnoskeletalfeaturethatrivalsthedefinitivenessofdifferencesbetweenfleshedindividuals.3.Cross-dressersarealsoaproblemandidentificationmaybedelayedorevenimpossiblewithoutathoroughskeletalexamination.4.Onemustbeparticularlycarefulinmassdisasterswherebothbonesandpersonalitemsmaybecomingled.SexualDimorphism

Innormal,livinghumans,sexisadiscretetraitdeterminedbytheactionsoftheXXorXYgenotypeanddiagnosedbyobservingoneofonlytwopossiblemorphologicalfeatures.Thesedifferences(e.g.externalgenitalia)areapparentatbirthandclearlyrecognizableevenduringtheprenatalperiod.Intheskeleton,however,themosteffectivesexindicatorsdonotbegintodevelopuntil

adolescence,andsomearenotfullyexpresseduntiladulthood.Althoughalmosteveryhumanbonehasbeenanalyzed,bothmetricallyandmorphologically,evenacomplete,maturepelviscannotconsistentlyguaranteemorethan95%separationofthesexes.Therearetwomethodologicalapproachestosexingskeletalremains:morphologicalandosteometric.

Morphologictechniquesfocusonshape–thebonyconfigurationsthataremacroscopicallyvisibleanddifferbetweenmalesandfemales.Metricanalysis,basedonbonedimensions,isthemethodofchoiceforskeletalpartslikelongbonesthatdonotexhibitclearlydefinableshapevariants.SexualDimorphism

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BasicPrinciples

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SexualDimorphism

Size:malesusuallylargerRobusticityandmuscularity–usuallymoreevidentinmalesTheImmatureSkeleton

Figure1.Sexdifferencesintheimmaturemandible.Femalemorphology(above)hasaroundedcorpusshapewithagradualtransitionfromthelateralbodytothesymphysis.Males(below)showasteepabrupttransitionwithanangularcorpus(notdentalarcade)shapeTheAdultSkeleton:Morphology

Whenthemorphologicexpressionsofsexualdimorphismintheadultskeletonareeasilydistinguishabletheyprovidethemostconsistentlyreliablemeansofdiagnosingsex.Thebestplacestolookfortheseformationsaretheskullandpelvis.Sexdifferencesintheskullaremainlyduetosexualdimorphism.Themaleislarger,morerugged,andmusclemarked;whereasthefemaleissmaller,moregracileandsmooth.Skull

Supraorbitalridgemoremarkedinmales1.SexEstimation–Skull–SupraorbitalRidgeMaleskullislarger,hasamoreslopingforehead.Femaleskullissmaller;retainsfrontalandparietalbossing2.SexEstimation–Skull–Vault2.SexEstimation–Skull–VaultPosteriorendofzygomaticarchextendsassupramastoidcrestfartherinmales2.SexEstimation–Skull–VaultMastoidprocessislargerandmorebluntinmales,smallerinfemales.2.SexEstimation–Skull–VaultInionmaybemoreprominentinmales,sometimestopointofappearinghook-shaped2.SexEstimation–Skull–VaultZygomaticarchwiderinmales,narrowerinfemalesTheskull

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Sexdifferencesintheskull(A)Malefeatures;(B)femalefeatures;(C)morphologicgradations.部位男性女性(1).整體大而重，骨壁厚，顱腔較大，顱容量約1450毫升。小而輕，骨壁薄，顱腔小，顱容量約1300毫升。(2).結構凹突不平，肌脊明顯。較光滑，肌脊不發達。(3).乳突發達，平放時乳突尖可成為支點。不發達，平放時乳突尖不成為支點。(4).枕部肌脊與枕外隆凸明顯。肌脊與枕外隆凸不明顯。(5).額部額鱗斜度較大，表面不圓。額鱗斜度小，較圓而豐滿。(6).額結節與頂結節較小較大(7).眉間突度大，突出于鼻根。小，較平直。(8).鼻根點凹陷較深。較淺。(9).眉弓中等至特明顯。微顯至中等。(10).眼眶類方形，較低，相對較小，眶上緣鈍。類圓形，較高，較大，眶上緣銳。(11).齒槽弓較大，近U形。較小而尖，拋物線形。(12).枕骨髁大小(13).枕骨大孔大小(14).梨狀孔形狀高而窄低而圓(15).面部長短(16).顴骨高而粗壯，顴弓較粗。低而薄弱，顴弓較細。3.SexEstimation–Skull–MandibleChinmoresquareinmales,roundedinfemales;teethlargerinmalesFigure2

Sexdifferenceintheadultmandible.Theposteriorramusofadultmales(left)isflexedattheleveloftheocclusalsurfaceofthemolars.Thefemaleramusmaintainsthestraightjuvenileshape(topright)ormayflexabovetheocclusallevelneartheneckofthecondyle(lowerright).3.SexEstimation–Skull–Mandible部位男性女性(1).整體較粗大、厚、重。較薄、弱、輕。(2).下頜體較高、平均29mm。較低、平均26mm。(3).頦部。發達，近方形，骨較厚。較弱，圓而尖，骨較薄。(4).下頜角較粗糙，外翻，角度較小，<120度。較光滑，外翻不明顯，角度較大，>125度。(5).下頜支較寬較窄(6).下頜髁突肥大，壯實。較弱小。下頜骨的性別鑒定

Pelvis

ThebestareatodeterminesexfromthehumanskeletonisthepelvisThepelvisFigure4

SexdifferencesinthepelvisMaleabove,femalebelowSeealsoP30ofthetextbookwhichpelvisisman’s?WHY?部位男性女性(1).整體高而狹窄，骨質重，骨面粗糙，髂翼厚。低而寬闊，骨質輕，骨面光滑，髂翼薄而透光。(2).骨盆上口心形，縱徑>橫徑。橢圓形，橫徑>縱徑。(3).骨盆腔高而窄,漏斗形。短而寬，圓柱形。(4).骨盆下口狹小。寬闊。(5).骶骨窄長三角形，彎曲度大。短寬三角形，彎曲度小。(6).骶骨岬顯著。不顯著。(7).耳狀面大而直，涉及3個骶椎。小而傾斜，涉及2個骶椎。(8).髂翼較直而高。低而外張。(9).髖臼大，向外。小，向前外。(10).恥骨聯合高。低。(11).恥骨弓角約70~75度，V形。約90~110度，U形。(12).坐骨結節不外翻，坐骨結節間距<9cm。外翻，坐骨結節間距>9cm。(13).閉孔大，卵圓形。小，三角形。骨盆的性別鑒定

ParturitionScars

Inthelast30years,therehasbeenconsiderabledebateastowhetheronecandetermineifpregnancyandparturitionleavetracesintheskeleton.Theinitialhypothesiswasthattheseprocessescanteartheligamentsofthepubicbonesandsacroiliacjointandareresponsibleforcausingscarsorpitsatthesesites.These