FORENSIC ODONTOLOGY

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FORENSIC ODONTOLOGY
prepared and presented by shabeel pn
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• 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

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• 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

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• 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

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• 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

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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

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• 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

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• 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

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• 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

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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

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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

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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

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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

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• 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

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• 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

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• 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

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• 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

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• 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

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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

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• 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

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• 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

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• 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

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• 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

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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

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• 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

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• 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

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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

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• 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

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• 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)

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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

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• 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

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• 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

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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

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• 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

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• 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

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• CRANIOFACIAL MORPHOLOGIC INDICATOR OF SEX
• Skull features

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• CRANIAL MEASUREMENT (IN MM)USEFUL IN SEXING

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• ODONTOMETRIC DIFFERENCES

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• DENTAL INDEX

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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)

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• 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.

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• 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)

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• 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

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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)

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• 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)

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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.

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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
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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
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• 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
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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
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• 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
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• 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
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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.

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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

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

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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

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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

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Bite mark analysis and comparison

• Jaw movement
• Flexibility of bitten tissue
• Individual features of bite marks
• Metric analysis
• Computer software program

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Conclusion Of Bite Mark Analysis

• Positive identification
• Possible identification
• Excludes identification

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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

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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

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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