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FORENSIC ODONTOLOGY

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Title: FORENSIC ODONTOLOGY


1
FORENSIC ODONTOLOGY
prepared and presented by shabeel pn
2
  • FORENSIC IS DERIVED FROM THE LATIN WORD FORUM
    WHICH MEANS COURT OF LAW
  • ODONTOLOGY?STUDY OF TEETH
  • DEFINED AS THAT BRANCH OF DENTISTRY WHICH ,IN THE
    INTEREST OF JUSTICE ,DEALS WITH THE PROPER
    HANDLING AND EXAMINATION OF DENTAL EVIDENCE,AND
    WITH THE PROPER EVALUATION AND PRESENTATION OF
    DENTAL FINDINGS

3
  • FORENSIC DENTISTRY PLAYS A MAJOR ROLE IN
    IDENTIFICATION IN MAN MADE OR NATURAL DISASTER
    EVENTS THAT RESULT IN MULTIPLE FATALITIES THAT
    MAY NOT BE IDENTIFIABLE THROUGH CONVENTIONAL
    METHODS SUCH AS FINGER PRINTS

4
  • THE EARLIEST KNOWN EXAMPLE BY DENTAL MEANS DATES
    BACK TO 66 AD
  • ELABORATE DENTAL RECORDS INCLUDING RADIOGRAPHS
    AND SPARE CROWNS IDENTIFIED THE BODY OF ADOLPH
    HITLER ,THE MOST HIGH PROFILE CASE OF DENTAL
    IDENTIFICATION
  • IT RELIES ON SOUND KNOWLEDGE OF TEETH AND JAWS
    ,POSSESED BY DENTIST AND INCORPORATES DENTAL
    ANATOMY ,HISTOLOGY RADIOGRAPHY ,DENTAL MATERIALS
    AND DEVELOPMENTAL ANOMALIES

5
  • FORENSIC ODONTOLOGY DELVE INTO
  • IDENTIFYING UNKNOWN HUMAN REMAINS THROUGH DENTAL
    RECORDS ,AND ASSISTING AT LOCATION OF MASS
    DISASTER
  • ELICITING THE ETHNICITY AND ASSISTING IN BUILDING
    UP A PICTURE OF LIFESTYLE AND DIET OF SKELETAL
    REMAINS AT ARCHEOLOGICAL SITES
  • DETERMINIG THE GENDER OF AN UNIDENTIFIED
    INDIVIDUAL
  • AGE ESTIMATION OF BOTH THE LIVING AND DECEASED
  • RECOGNITION AND ANALYSIS OF BITE MARKS FOUND ON
    VICTIMS OF ATTACK AND OTHER SUBSTANCES SUCH AS
    FOOD STUFF
  • 6. PRESENTING EVIDENCE IN COURT AS AN EXPERT
    WITNESS

6
PERSONAL IDENTIFICATION
  • IDENTIFICATION IS THE ESTABLISHMENT OF A PERSONS
    INDIVIDUALITY
  • REQUIRED FOR LEGAL AND HUMANITARIAN REASONS
  • HELP IN SETTLEMENT OF PROPERTY ,FACLITATE
    REMARRIAGE OF A SURVIVING SPOUSE AND ALLOW
    CREMATION OR BURIAL OF THE BODY ,ACCORDING TO
    RELAVENT RELIGIOUS AND CULTURAL CUSTOMS

7
  • TRADITIONAL METHODS
  • VISUALLY RECOGNISING BODY
  • PERSONAL PROPERTY SUCH AS CLOTHING ,JEWELLERY ETC
  • VISUALLY IDENTIFYING THAT IS BURNT OR DECOMPODSED
    CAN BE AVERY TRAUMATIC EXPERIENCE FOR RELATIVES
    AND FRIENDS ,THE BETTER OPTION IDENTIFICATION IS
    FORENSIC EXPERT TO ANALYSE PHYSICAL FEATURES
    PRESENT IN THE BODY

8
  • PHYSICAL FEATURES ARE PRONE TO CHANGE OVER TIME
    ,FINGER PRINTS ARE EXCEPTIONS BUT LIKE OTHER SOFT
    TISSUE,UNDERGO POST MORTUM CHANGE
  • BEING THE STRONGEST STRUCTURE PRESENT IN THE BODY
    DENTAL HARD TISSUES ARE RESISTANT TO POST MORTUM
    DECOMPOSITION

9
  • MOREOVER MOST MATERIAL USED BY DENTIST FOR
    RESTORING TEETH ARE ALSO RESISTANT TO POST MORTUM
    DESTRUCTION
  • THEREFORE THE USE OF DENTAL EVIDENCE IS THE
    METHOD OF CHOICE IN ESTABLISHING THE IDENTITY OF
    BADLY BURNT ,TRAUMATISED,DECOMPOSED AND
    SKELETONISED REMAINS

10
BASIS FOR DENTAL IDENTIFICATION
  • HUMAN DENTITION IS NEVER SAME IN ANY TWO
    INDIVIDUALS
  • THE ,MORPHLOGY AND ARRANGEMENT OF TEETH VARY FROM
    PERSON TO PERSON
  • TEETH ARE RELATIVELY RESISTANTNTO ENVIRONMENTAL
    INSULTS AFTER DEATH

11
DENTAL IDENTIFICATION PROCEDURES
  • TWO FORMS
  • 1. COMPARITIVE IDENTIFICATIONCOMPARING THE DEAD
    INDIVIDUALS TEETH WITH PRESUMED DENTAL RECORDS OF
    THE INDIVIDUAL
  • 2. RECONSTRUCTIVE IDENTIFICATION (DENTAL
    PROFILING)ATTEMPTS TO ELICIT THE ETHNICITY OR
    RACE ,GENDER , AGE AND OCCUPATION OF THE DEAD
    INDIVIDUAL.UNDERTAKEN WHEN VIRTUALLY NO CLUE
    EXISTS

12
COMPARITIVE DENTAL IDENTIFICATION
  • INCLUDES FOUR STEPS
  • STEP 1ORAL AUTOPSY
  • STEP 2OBTAINING DENTAL RECORDS
  • STEP 3COMPARING POST MORTUM AND ANTIMORTUM
    DENTAL DATA
  • STEP 4WRITTIN A REPORT AND DRAWING CONCLUSION

13
ORAL AUTOPSY
  • ALSO KNOWN AS NECROPSY OR POST MORTUM
  • IT HAS A SYSTEMATIC PROTOCOL STARTING WITH
    CRITICAL EXAMINATION OF THE EXTERNAL FEATURES OF
    THE BODY SUCH AS GENDER, ETHNICITY ,BUILT,
    WOUNDS.SCARS ,TATTOOS AND BODY PIERCING.
  • PHOTOGRAPHS, RADIOGRAPHS,FINGERPRINTS,FINGER NAIL
    SCRAPING AND HAIR SAMPLE MAY BE OBTAINED
    ACCORDING TO THE REQUIREMENTS

14
  • ORAL EXAMINATION IS AN ESSENTIAL PART OF
    POSTMORTUM PROCEDURS
  • A FORENSIC DENTIST WHO CONDUCT ORAL AUTOPSY
    SHOULD HAVE ADEQUATE KNOWLEDGE ABOUT COMMON
    POSTMORTUM FINDINGS SUCH AS RIGOR MORTIS ,LIVER
    MORTIS ,DECOMPOSITION AND POSTMOTUM ARTEFACTS
  • RIGOR MORTIS MAY RENDER THE JAW AND THE USE OF
    MOUTH GAGS OR INTRA ORAL MYOTOMY IS ESSENTIAL FOR
    JAW SEPERATION

15
  • Since teeth may be brittle in burned cases, they
    need to be reinforced with cyanoacrylate cements,
    polyvinyl acetate or clear acrylic spray prior to
    examination
  • Access for radiology in incinerated bodies can be
    obtained by removing tongue and contents of floor
    of mouth in a tunneling fashion from beneath
    the skin
  • The status of each tooth whether intact carious
    restored or missing should be carefully noted
  • A thorough examination of soft tissue injuries,
    fracture and presence of foreign bodies is under
    taken and samples of hard and soft tissues may be
    obtained for further investigation
  • All information pertaining to the body must be
    entered on to standard interpol post-mortem
    form, which is color-coded in pink

16
  • OBTAINING DENTAL RECORDS
  • FROM TREATING DENTIST,SPEACILIST,HOSPITAL RECORDS
    IN THE FORM OF DENTAL CHARTS RADIOGRAPHS,CASTS,
    AND/OR PHOTOGRAPHS
  • CONTENT OF ALL AVAILABLE RECORDS SHOULD BE
    TRANSCRIBED ON TO THE STANDARD INTERPOL
    ANTEMRTEM FORM WHICH IS COLOUR CODED IN YELLOW

17
  • COMPARNG POST-MORTEM ANTE-MORTEM DENTAL RECORDS
  • FEATURES COMPARED INCLUDE TOOTH MORPHOLOGY AND
    ASSOSIATED BONY STRUCTURES, PATHOLOGY AND
    RESTORATIONS
  • AN INDIVIDUAL WITH MULTIPLE DENTAL TREATMENT AND
    UNUSUAL FEATURES HAS A BETTER LIKELIHOOD OF BEING
    IDENTIFIED THAN SOMEONE WITH NO EXTRAORDINARY
    DENTAL CHARECTERISTICS
  • COMPARISON SHOULD TAKE IN TO ACCOUNT QUALITY
    RATHER THAN QUANTITY

18
  • WRITING A REPORT AND DRAWING CONCLUSION
  • CONFIRMS IDENTIFICATIONMATCH EACH OTHER
  • PROBABLE IDENTIFICATIONHIGH LEVEL OF CONCORDANCE
    BETWEEN THE TWO SETS OF DATA BUT,USUALLY ,WITH NO
    RADIOGRAPHIC SUPPORT
  • POSSIBLE IDENTIFICATIONEXPLAINABLE
    IDENTIFICATION BETWEEN THE ANTE AND POST-MORTEM
    DATA
  • INSUFFICIANT INFORMATIONAVAILABLE
    ANTIPOS-MORTEM DATA ARE INSUFFFICIANT
  • EXCLUDES IDENTIFICATIONANTIPOST MORTEM DATA ARE
    CLEARLY INCONSISTENT

19
IDENTIFICATION IN DISASTERS
  • INVOLVES COMPARING HUNDREDS OR THOUSANDS ,OF ANTE
    POST MORTEM DATA
  • HUMAINS REMAINS IN SUCH EVENTS MAY BE HIGHLY
    FRAGMENTED , ONLY PART OF BODY MAY BE RECOVERED
    THE NODIES MAY BE INCINERATED OR COMMINGLED i.e.
    PARTS OF TWO BODIES MAY BE MIXED

20
  • DENTAL SECTION
  • FORENSIC DENTIST ARE USUALLY PART OF A TEAM OF
    IDENTIFICATION SPECIALIST
  • THREE SUB SECTIONS
  • 1.POST MORTEM UNITS
  • 2.ANTE MORTEM UNITS
  • 3.DENTAL COMPARISON IDENTIFICATION UNITS

21
  • POST-MOTEM UNIT
  • THE LOCATION AT WHICH A BODY IS RECOVERED NOTED
    AND PRELIMINARY EXAMINATION OF MOUTH IS MADE TO
    EVALUATE THE ORAL CONDITION
  • DEFINITIVE EXAMINATION AT MORTURY OF POST-MORTUM
    UNIT
  • A PORTABLE DENTAL RDIGRAPHY SHOULD BE INSTALLED,
    TAKING PRECAUTIONS AGAINST RADIATION HAZARDS
  • RESPONSIBLE FOR PROCESSING RADIOGRAPHS MAY ALSO
    NEED ARRANGE FOR PHOTOGRAPHY OF TEETH
  • TEETH AND JAW SPECIMEN MAY BE REMOVED FROM A BODY
    FOR THE CONVEININCE OF EXAMINATION

22
  • ANTE-MORTEM UNIT
  • MOST DIFFICULT.
  • THE MEMBERS NEED TO COLLECT AS MUCH AS
    INFORMATION AS POSSIBLE IN THE SHORTEST PERIOD OF
    TIME
  • BEGINS WITH LOCATING THE DENTAL RECORDS OF THE
    VICTIMS ?COMMUNICATING WITH POLICE, DENTIST, AND
    RELATIVES OF THE VICTIMS
  • ALL INFORMATION OBTAINED MUST BE TRANSFERRED ONTO
    THE STANDARD INTERPOL ANTE-MORTEM FORM
  • THIS CONSTITUTE THE ANTE MORTEM COMPOSITE CHART

23
  • DENTAL COMPARISON AND IDENTIFICATION UNIT
  • COMPARISON AND CONFORMATION OF IDENTIFICATION
  • THE ANTE-MORTEM DATA ARE TAKEN INDIVIDUALLY AND
    COMPARED TO THE POST-MORTEM DATA THAT ARE SPREAD
    OUT (COMPUTER SOFTWARE DEVELOPED TO SIMPLIFY
    COMPARISON )
  • FINAL IDENTIFICATION SHOULD ALWAYS BE DONE BY
    DENTIST MANUALLY

24
IDENTIFICATION FROM DENTAL DNA
  • TEETH ARE EXCELLENT OURCE OF DNA SINCE IT CAN
    RESIST EXTREME CONDITION
  • PCR ALLOWS AMPLIFICATION OF EVEN HIGHL DEGRADED
    DNA
  • MAJOR ADVANTAGE IS THAT IF DECENDENTS ANTE MOTEM
    SAMPLE (HAIR FROM HAIR BRUSH, EPITHELIAL CELLS
    FROM TOOTH BRUSH OR BIOPSY)IS UNAVAILABLE ,THE
    DNA PATTEN MAY BE COMPARED TO A PARENT OR TO A
    SIBLING

25
  • EXTRACTION OF DENTAL DNA
  • PULPAL TISSUE BEST SOURCE OF DENTAL DNA
  • CRYOGENIC GRINDING FOR EXTRACTING DNA(COOLING THE
    WHOLE TOOTH TO EXTREMLY LOW TEMPERATURE,AND THEN
    MECANICALLY GRINDING IT TO FINE POWDER)?TOOTH
    WILL BE COMPLETELY CRUSHED
  • ANOTHER METHOD?DRILLING OF THE ROOT CANALS,
    SCRAPING THE PULPAL AREA WITH A NOTCHABLE MEDICAL
    NEEDLE,AND SUBSEQUENT FLUSHING OF THE TIISSUE
    DEBRIS

26
  • TYPES OF DNA
  • TWO TYPES OF DNA
  • 1)GENOMIC OR NUCKEAR DNA
  • 2)MITOCHONDRIAL DNA (mtDNA)
  • EACH CELL HAS A HIGH COPY OF mt DNA ,ALSO
    EXCLUSIVELY INHERITED FROM MOTHERNO CONTRIBUTION
    FROM FATHER
  • THUS IDENTICAL mtDNA IS OBSERVED IN SIBLINGS,
    THEIR MOTHER AND MANY MATERNAL RELATIVES

27
THE PALATAL RUAE IN IDENTIFICATION
  • USEFUL IN EDENTULOUS PERSONS
  • RGAE PATTERNS LIKE TEETH ARE CONSIDERED UNIQUE TO
    AN INDIVIDUAL
  • RUGAE PATTERNS ON THE DECEDENTS MAXILLA OR
    MAXILLARY DENTURES MAY BE COMPARED TO OLD
    DENTURES THAT MAY BE REOVERED FROM THE DECEDENTS
    RESIDENCE,OR PLASTER MODEL FROM DENTAL OFFICE

28
  • CLASSIFICATION OF PALATAL RUGAE
  • LYSELL MEASURED RUGAE IN ASTRAIGHT LINE FROM
    MEDIAL TO LATERAL AND CATEGORIZED AS
  • -PRIMARY RUGAE (gt5mm)
  • -SECONDARY RUGAE(3-5mm)
  • -FRAGMANTARY RUGAE (2-3mm)
  • (RUGAE lt2mm IS NOT TAKEN IN TO
    CONSIDERATION)
  • THOMAS KOTZE HAVE FURTHER DETAILED VARIOUS
    PATTERNS OF PRIMARY RUGAE BRANCHED ,UNIFIED ,
    CROSSLINKED , ANNULAR , PAPILLARY

29
  • ANALYSIS OF RUGAE PATTERNS
  • THOMAS AND VAN WYK HAVE MANUALLY TRACED RUGAE
    PATTERN ON PHOTOGRAPHS OF PLASTER MODEL
  • RECENTLY, LIMSON AND JULIAN HAVE DEVELOPED A
    COMPUTER SOFT WARE PROGRAM,RUGFP-ID MATCH(SAME
    PRINCIPLE OF FINGER PRINTING)

30
DENTAL PROFILING
  • WHEN ANTE-MORTEM RECORDS ARE NOT AVAILABLE
  • INCLUDES A TRIAD OF INFORMATION?ETHNIC ORIGIN ,
    GENDER , AGE
  • INFORMATION FROM THIS PROCESS WILL ENABLE A MORE
    FOCUSSED SEARCH FOR ANTE-MORTEM RECORDS

31
  • IDENTIFY ETHNIC ORIGIN FROM THE TEETH
  • HUMAN RACES HAVE BEEN DIVIDED IN TO THREE RACES
    CAUCASOID, MANGALOID AND NEGROID
  • IT IS POSSIBLE TODAY TO IDENTIFY AN INDIVIDUALS
    ETHNIC ORIGIN BASED PURELY ON ONES DENTITION

32
  • GENETIC AND ENVIRONMENTAL INFLUENCE ON TEETH
  • DENTAL FEATURES HAVE COMPLEX MODE OF INHERITENCE
    AND ARE COMBINATION OF HERIDITY AND ENVIRONMENTAL
    FACTORS TO WHICH PERSON IS EXPOSED
  • SO DIFFERENT POPULATION SHOW CONSIDERABLE
    VARIATION
  • DENTAL FEATURES IN POPULATION DIVIDED IN TO
  • 1)METRIC(TOOTH SIZE)
  • 2)NON METRIC(TOOTH SHAPE)
  • MORE HERITABLEDEPENDABLE

33
NON METRIC DENTAL FEATURES
  • CROWN FEATURE
  • SHOVELLING,DOUBLE SHOVELLING,CAREBELLIS
    FEATURE,THREE CUSPED UPPER 2ND MOLAR,CUSP 5,
    CUSP 6,CUSP 7, WINGLING,FIVE -CUSPED LOWER SECOND
    MOLAR, LOWER MOLAR GROOVE PATTERN,INTERRUPTION
    GROOVE, ENAMEL EXTENSION, ODONTOME, LETAREL
    INCISOR VARIATION, DISTAL ACCESSORY RIDGE,
    PREMOLAR ACCESSORY RIDGE, PREMOLAR ACCESSORY
    MARGINAL TUBERCLE, PREMOLAR LINGUAL CUSP, MESIAL
    MARGINAL TUBERCLE OF UPPER MOLAR, PARASTYLE,
    PROTOSTYLID

34
  • ROOT FEATRES
  • TWO ROOTED UPPER PREMOLAR
  • TWO ROOTED UPPER MOLAR
  • TWO ROOTED LOWER CANINE
  • TOMES ROOT
  • THREE ROOTED LOWER MOLAR
  • SINGLE ROOTED LOWER MOLAR
  • OF THESE NON-METRIC DENTAL
    FEATURES SOME HAVE HIGH FREQUENCY IN CERTAIN
    POPULATION AND OTHER UNCOMMEN
  • Eg SOUTH-ASIANS EXHIBIT 4 CUSPED LOWER
    SECOND MOLAR BUT FEATURES LIKE WINGLING
    ,SHOWELLING,Y GROOVE PATTERN TOMES PATTERN

35
  • SEX DIFFERANTIATION
  • SECOND STEP
  • CAN BE DETERMINED
  • 1)SEXING FROM CRANIOFACIAL MORPHOLOGY AND
    DIMENSION
  • 2)SEX DIFFRENCES IN TOOTH SIZE
  • 3)DENTAL INDEX
  • 4)SEX DETERMINATION BY DNA ANALYSIS
  • 5)SEX DETERMINATION BY DNA ANALYSIS

36
  • CRANIOFACIAL MORPHOLOGIC INDICATOR OF SEX
  • Skull features











37
  • CRANIAL MEASUREMENT (IN MM)USEFUL IN SEXING

38
  • ODONTOMETRIC DIFFERENCES

39
  • DENTAL INDEX

40
Dental Age Estimation
  • Final step in dental profiling
  • Estimation methods
  • 1). Age estimation in prenatal, neonatal and
  • early post natal child
  • -by use of histologic technique (12 weeks
    before it is actually apparent on radiographs)
  • -by radiograph-non invasive
  • -neonatal line indicates a live births
  • -by dry weight of mineralized tooth (at six
    month IU- 60mg, newborn-0.5g, six month post
    natal-1.8g)

41
  • 2.Age estimation in children and adolescents
  • -two events may be used?eruption and tooth
    calcification
  • -various methods
  • a). Schowur and Masslers method described 20
    chronological stages of tooth development
    starting from 4 months IU until 21 years of age.
    It is based on histological section which permits
    direct comparison with radiographs
  • b).Demirjans method made use of a foreign
    system. Devolopment of Left side seven
    mandibular teeth was devided into 8 stages(A-H).
    Each tooth assaigned a maturity score and total
    maturity score of all teeth is plotted on a
    chronologic age conversion table. Separate
    maturity score and age conversion table for both
    sexes.

42
  • c). Third molar in age estimation A valuable
  • indicator in the age 16-23 years.
    but questionable now a days due to great
    variation in genesis, position, morphology and
    time of formation.
  • 3). Age estimation in adults
  • challenging when compared to young age groups as
    numerous endogenous and exogenous fqactors, such
    as disease, nutrition, physical strain
    influences.
  • a). Methods
  • Gustafsons method based on morphological and
    histological changes of the teeth. Accessed
    regressive changes such as
  • .amount of occlusal attrition (A)
  • .coronal secondary dentin deposition(S)
  • .loss of periodontal attachment(P)
  • .Cementum aposition at the root apex(C)
  • .Root resorbtion at apex(R)
  • .dentin translucency (T)
  • Each of regressive changes have seven grades
    (0,0.5,1,1.5,2,2.5,3)
  • Age 11.02(5.14A)(2.3S)(4.14P)(3.71C)(5.57R)
    (8.98T)

43
  • b). Dentin translucency root dentin starts to
    become translucent during the third decade of
    life beginning at the apex and advancing
    coronally. Hence as age advances refractive index
    between intratubular organic and extra tubular
    inorganic material is equalized resulting in
    increased translucency of the affected dentin
    zone.
  • Age B0B1X where B0 regression constant
  • B1-regression coefficient
  • X-length of translucency

44
C).Age Estimation from Incremental Lines Of
Cementum
  • From acellular cementum incremental lines
  • Made us of mineralized unstained cross-sections
    of teeth
  • D).Radiographic Method
  • Used pulp size mesurement of six teeth
  • 5 2 1 1 2 5
  • 4 2 1 1 2 4
  • Age 129.8-316.4(M)-66.8(W-L)

45
  • The measurement include several length and width
    ratios such as
  • pulp-root length? P
  • pulp-tooth length? R
  • pulp-root width at CEJ? A
  • pulp-root width at mid-root level? C
  • pulp-root width at mid-point between level C
  • and A ? B
  • mean value of all ratio including
  • excluding T? M
  • mean value of width ratios B and C? W
  • mean value of length ratio p and R? L
  • Age 129.8-316.4(M)-66.8(W-L)

46
Amino acid recemisation
  • Suggested a relationship between dentinal age and
    extent of aspartic acid recemisation in dentin.
  • Aspartic acid undergo rapid rate of recemisation
    and get spontaneously converted from L-Aspartic
    acid to D-Aspartic acid with increasing age.
  • Comparing D-L ratio age can be estimated.

47
Cranio-facial estimators of age
  • Cranial suture and also mandible provides certain
    characteristic for elicitation of age

Surture Endocranial initiation Ectocranial termination
Sagittal 21 35
Sphenoparietal 30 65
Coronal 25 39
Squamosal 37 80
Sphenotemporal 30 68
Lambdoid 26 41
Mastooccipetal 26 72
Sphenofrontal 24 35
48
INFANCY ADULT OLD AGE
BODY shallow Thick long shallow
RAMUS Forms an obtuse angle with the body Forms an approximate right angle Obtuse angle
MENATAL FORAMEN Located near lower margin of the body Midway between upper and lower margin Near alveolar margin
CONDYLE Occupies a lower level to the coronoid process Elongated and projects above the coronoid Neck is bent backwards
49
  • ODONTOMETRIC DIFFERENCE

TOOTH NO. MESIODISTAL M MESIODISTAL F BUCCOLINGUAL M BUCCOLIN- GUAL F
11 8.9 8.5 7.1 7.0
12 7.0 6.65 6.5 6.2
13 8.3 7.6 8.4 7.9
14 6.9 6.8 9.3 8.9
15 6.7 6.65 9.8 9.3
16 11.0 10.6 11.0 10.9
17 10.4 9.9 11.0 10.7
50
TOOTH NO. MESIODISTAL M MESIODISTAL F BUCCOLINGUAL M BUCCOLIN- GUAL F
41 5.5 5.3 6.2 6.1
42 6.1 5.9 6.5 6.5
43 7.2 6.6 7.55 7.4
44 7.1 7.0 7.9 7.6
45 7.4 6.9 8.6 8.2
46 11.1 10.8 10.4 10.2
47 10.5 10.2 10.3 9.9
51
  • Cranial measurement (in mm) useful in sexing
  • CRANIAL VARIABLES

Males Females
Cranial base length 112.5 103
Mastoid height 12.5 9.6
Mastoid width 24 19
Total face height 127 114
Bizygomatic breadth 129 122
Basion-nasion length 102 96
Cranial length 188 179
Nasal height 54 50
Maximum frontal width 120 115.5
52
  • Cranial measurement (in mm) useful in sexing
  • MANDIBLE VARIABLES

Male Female
Bicondylar breadth 117 111
Bigonial breadth 100 91.5
Minimum ramus breadth 31 28.5
Gonion-gnathion breadth 77 73
Total mandibular length 111 108
53
CRIME INVESTIGATION
  • BITE MARKS
  • A mark caused by teeth either alone or in
    combination with other mouth parts (Mac Donald).
  • May be caused by humans or animals may be on
    tissue, food items or other objects.
  • Human bite? broad, U-shaped somewhat circular or
    oval.
  • Animal bite? narrow in the anterior aspect , V
    shaped and elongated also morphology of the teeth
    is different.

54
Classification of bite marks
  • 1.Cameron and Sims Classification
  • Agents
  • Humans
  • Animals
  • Materials
  • skin,body tissue
  • food stuff
  • other materials
  • 2.Mac Donalds classifications
  • Tooth pressure mark
  • Tongue pressure mark
  • Tooth scrape mark

55
  • 3. Websters classification
  • Type I
  • Type II
  • Type III

56
Bite mark appearance
  • Type of injury
  • Identifying The Injury As a Bite Mark
  • a). Gross features Circular or ellipticalwith
    central area of ecchymosis
  • b). Class features Incisor?rectangular
  • Canines?triangular or rectangular
  • Premolars and molars? spherical or point
    shaped
  • c). Individual features Class features intern
    have characteristics such as fractures
    rotation etc.
  • Site of Bite Marks
  • Females? on breast, legs( inner part of
    thigh)-sexual assault
  • Male children? genitals-child abuse
  • Adult Males? finger, arms and shoulders-fight

57
Bite mark investigation
  • Preliminary questions
  • Bite mark evidence collection from the victims
  • if criminal in nature is reported to law
    enforcement agencies
  • Steps
  • 1.Visual examination
  • 2.Photography
  • Orientation photographs
  • close-up photographs
  • 3.Saliva swab WBC and sloughed epithelial
    cells, potential source of DNA
  • 4.Impression Vinyl polysiloxane
  • 5.Evidence collection from suspect using a
    signed and informed consents or a court
    order (warrant) also include photograph, two
    casts, bite registration in centric occlusion and
    saliva swab from buccal vestibule

58
Bite mark analysis and comparison
  • Jaw movement
  • Flexibility of bitten tissue
  • Individual features of bite marks
  • Metric analysis
  • Computer software program

59
Conclusion Of Bite Mark Analysis
  • Positive identification
  • Possible identification
  • Excludes identification

60
Investigating Animal Bites
  • Characteristics of some vertebrate dentition
  • fish? conical, homodont, heterodont or
    polyphydont
  • Reptiles? homodont conical or only
    tricuspid teeth
  • Venomous snake? single row, palatal to this
    are two poison fangs containing canal or groove
    for venom release
  • Non-Venomous? two rows of maxillary teeth
  • Mammals? heterodont dentition, diphyodont also
    have accesssional teeth( permanent molar emerge
    posterior to deciduous teeth)
  • carnivores? i

61
Lip Prints
  • Examination of lip print-cheloscopy
  • Grooves an wrinkles visible on lips named as
    sulci, labiorum rubrorum
  • Grooves are heritable and suppose to be
    individualistic? so material evidence left at a
    crime scene similar to finger prints
  • Lip prints classified as
  • I) a) simple wrinkles
  • straight line
  • curved line
  • angled line
  • sine shaped curve
  • b) compound wrinkles
  • Bifurcated
  • trifurcated
  • anomalous
  • II)type 1- clear cut vertical grooves that run
    across the entire lip
  • type 1-similar to type 1 but not cover the
    entirely
  • type 2- branched grooves
  • type 3- intercepted grooves
  • type4- recticular grooves
  • type 5- grooves that can not be morphologically
    differentiated

62
DENTIST AS AN EXPERT WITNESS
  • Expert witness are those whose training,
    qualification or experience enables them to give
    an opinion on relevant matter where the ordinary
    person is not so enabled.
  • To become dental expert to forensic dental expert
    need additional knowledge and experience
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