FORENSIC ODONTOLOGY

• FORENSIC IS DERIVED FROM THE LATIN WORD FORUM WHICH MEANS COURT OF LAW

• ODONTOLOGYSTUDY 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

• 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

• 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

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

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

TRADITIONAL METHODS • VISUALLY RECOGNISING BODY• PERSONAL PROPERTY SUCH AS

CLOTHING ,JEWELLERY ETCVISUALLY 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

• 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

• 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

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

DENTAL IDENTIFICATION PROCEDURES

• TWO FORMS:1. COMPARITIVE IDENTIFICATION:COMPARING

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

COMPARITIVE DENTAL IDENTIFICATION

• INCLUDES FOUR STEPS

STEP 1:ORAL AUTOPSY

STEP 2:OBTAINING DENTAL RECORDS

STEP 3:COMPARING POST MORTUM AND ANTIMORTUM DENTAL DATA

STEP 4:WRITTIN A REPORT AND DRAWING CONCLUSION

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

• 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

• 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

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

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

WRITING A REPORT AND DRAWING CONCLUSION

• CONFIRMS IDENTIFICATION:MATCH EACH OTHER

• PROBABLE IDENTIFICATION:HIGH LEVEL OF CONCORDANCE BETWEEN THE TWO SETS OF DATA BUT,USUALLY ,WITH NO RADIOGRAPHIC SUPPORT

• POSSIBLE IDENTIFICATION:EXPLAINABLE IDENTIFICATION BETWEEN THE ANTE AND POST-MORTEM DATA

• INSUFFICIANT INFORMATION:AVAILABLE ANTI&POS-MORTEM DATA ARE INSUFFFICIANT

• EXCLUDES IDENTIFICATION:ANTI&POST MORTEM DATA ARE CLEARLY INCONSISTENT

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

DENTAL SECTION• FORENSIC DENTIST ARE USUALLY

PART OF A TEAM OF IDENTIFICATION SPECIALIST

• THREE SUB SECTIONS1.POST MORTEM UNITS

2.ANTE –MORTEM UNITS

3.DENTAL COMPARISON IDENTIFICATION UNITS

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

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

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

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 DECENDENT’S 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

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 METHODDRILLING OF THE ROOT CANALS, SCRAPING THE PULPAL AREA WITH A NOTCHABLE MEDICAL NEEDLE,AND SUBSEQUENT FLUSHING OF THE TIISSUE DEBRIS

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 MOTHER;NO CONTRIBUTION FROM FATHER

• THUS IDENTICAL mtDNA IS OBSERVED IN SIBLINGS, THEIR MOTHER AND MANY MATERNAL RELATIVES

THE PALATAL RUAE IN IDENTIFICATION

• USEFUL IN EDENTULOUS PERSONS• RGAE PATTERNS LIKE TEETH ARE

CONSIDERED UNIQUE TO AN INDIVIDUAL• RUGAE PATTERNS ON THE DECEDENT’S

MAXILLA OR MAXILLARY DENTURES MAY BE COMPARED TO OLD DENTURES THAT MAY BE REOVERED FROM THE DECEDENT’S RESIDENCE,OR PLASTER MODEL FROM DENTAL OFFICE

CLASSIFICATION OF PALATAL RUGAE • LYSELL MEASURED RUGAE IN ASTRAIGHT

LINE FROM MEDIAL TO LATERAL AND CATEGORIZED AS

-PRIMARY RUGAE (>5mm)

-SECONDARY RUGAE(3-5mm)

-FRAGMANTARY RUGAE (2-3mm)

(RUGAE <2mm IS NOT TAKEN IN TO CONSIDERATION)

• THOMAS &KOTZE HAVE FURTHER DETAILED VARIOUS PATTERNS OF PRIMARY RUGAE –BRANCHED ,UNIFIED , CROSSLINKED , ANNULAR , &PAPILLARY

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)

DENTAL PROFILING

• WHEN ANTE-MORTEM RECORDS ARE NOT AVAILABLE

• INCLUDES A TRIAD OF INFORMATIONETHNIC ORIGIN , GENDER , AGE

• INFORMATION FROM THIS PROCESS WILL ENABLE A MORE FOCUSSED SEARCH FOR ANTE-MORTEM RECORDS

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 INDIVIDUAL’S ETHNIC ORIGIN BASED PURELY ON ONE’S DENTITION

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 HERITABLE&DEPENDABLE

NON METRIC DENTAL FEATURES

CROWN FEATURE

SHOVELLING,DOUBLE SHOVELLING,CAREBELLI’S 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

ROOT FEATRES

TWO ROOTED UPPER PREMOLARTWO ROOTED UPPER MOLARTWO ROOTED LOWER CANINETOMES ROOTTHREE ROOTED LOWER MOLARSINGLE ROOTED LOWER MOLAR

OF THESE NON-METRIC DENTAL FEATURES SOME HAVE HIGH FREQUENCY IN CERTAIN POPULATION AND OTHER UNCOMMEN

Eg: SOUTH-ASIAN’S EXHIBIT 4 CUSPED LOWER SECOND MOLAR BUT FEATURES LIKE WINGLING ,SHOWELLING,Y GROOVE PATTERN TOMES PATTERN

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

CRANIOFACIAL MORPHOLOGIC INDICATOR OF SEX

Skull features

CRANIAL MEASUREMENT (IN MM)USEFUL IN SEXING

ODONTOMETRIC DIFFERENCES

DENTAL INDEX

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)

2.Age estimation in children and adolescents-two events may be usederuption and tooth

calcification-various methodsa). Schowur and Massler’s 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).Demirjan’s 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.

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:Gustafson’s 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)

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= B0+B1X where B0 –regression constant

B1-regression coefficient

X-length of translucency

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)

• The measurement include several length and width ratios such as:

pulp-root length Ppulp-tooth length Rpulp-root width at CEJ Apulp-root width at mid-root level Cpulp-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 Wmean value of length ratio p and R L

Age = 129.8-316.4(M)-66.8(W-L)

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.

Cranio-facial estimators of age• Cranial suture and also mandible provides certain

characteristic for elicitation of age

Surture Endocranial initiation

Ectocranial termination

Sagittal 21 35Sphenoparietal 30 65Coronal 25 39Squamosal 37 80Sphenotemporal 30 68Lambdoid 26 41Mastooccipetal 26 72Sphenofrontal 24 35

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 bentbackwards

• ODONTOMETRIC DIFFERENCE

TOOTH NO.

MESIODISTAL M

MESIODISTAL F

BUCCOLINGUAL M

BUCCOLIN-GUAL F

11 8.9 8.5 7.1 7.012 7.0 6.65 6.5 6.213 8.3 7.6 8.4 7.914 6.9 6.8 9.3 8.915 6.7 6.65 9.8 9.316 11.0 10.6 11.0 10.917 10.4 9.9 11.0 10.7

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

• Cranial measurement (in mm) useful in sexing• CRANIAL VARIABLES

Males FemalesCranial base length 112.5 103Mastoid height 12.5 9.6Mastoid width 24 19Total face height 127 114Bizygomatic breadth 129 122Basion-nasion length 102 96Cranial length 188 179Nasal height 54 50Maximum frontal width 120 115.5

• 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

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.

Classification of bite marks

1.Cameron and Sims ClassificationAgents

HumansAnimals

Materialsskin,body tissuefood stuffother materials

2.Mac Donald’s classificationsTooth pressure markTongue pressure markTooth scrape mark

3. Webster’s classification

Type I

Type II

Type III

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: Incisorrectangular Caninestriangular or rectangular Premolars and molars spherical or point shapedc). 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 abuseAdult Males finger, arms and shoulders-fight

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 examination2.Photography

Orientation photographsclose-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

Bite mark analysis and comparison

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

Conclusion Of Bite Mark Analysis

• Positive identification • Possible identification • Excludes identification

Investigating Animal Bites• Characteristics of some vertebrate dentition

fish conical, homodont, heterodont or polyphydontReptiles homodont conical or only tricuspid teeth

Venomous snake single row, palatal to this are two poison fangs containing

canal or groove for venom releaseNon-Venomous two rows of maxillary

teethMammals heterodont dentition, diphyodont also

have accesssional teeth( permanent molar emerge posterior to deciduous teeth)

carnivores i

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 lineangled linesine shaped curve

b) compound wrinklesBifurcated trifurcatedanomalous

II)type 1- clear cut vertical grooves that run across the entire liptype 1’-similar to type 1 but not cover the entirelytype 2- branched groovestype 3- intercepted groovestype4- recticular groovestype 5- grooves that can not be morphologically differentiated

• Invisible prints can be lifted using materials such as aluminum powder, magnetic powderDISADVATAGE1. Trauma, pathosis, surgical treatment can affect the size and shape of the lip2. The zone of transition close to vermilian border is extremely mobile so prints produced may differ

depending on pressure applied and its direction

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