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Dental Detectives - Forensic Odontology
Dental records and forensic odontology can be used to identify individuals and aid in criminal investigations. Teeth provide unique and durable evidence because they are resistant to heat, trauma, and decomposition. Forensic dentists examine dental records, bite marks, teeth, and other dental evidence to determine factors like identification, age, sex, and habits. Positive identification relies on sufficient unique dental characteristics matching between ante-mortem and post-mortem records, while exclusions can be as important as identifications. Teeth allow estimation of age through development, wear, and microscopic changes. Sex can be estimated through morphological traits and molecular analysis of cells from teeth. Forensic dentistry is an important tool for justice.
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Dental Detectives - Forensic Odontology
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- 2. Criminals & Crimes Terroristsand Terrorism Frauds and Cheatings Lead To Loss of Lives, Prosperity & Peace Dental Specialists enable rendering of Criminal Justice
- 3. DENTAL DETECTIVES ITS ALLABOUT INVESTIGATIONS… DR. NEERAJ TANEJA Asso Professor MDS, MBA, PGDFS
- 4. KEISER and NEILSONin 1970 It is a branch of odontology which deals with the proper handling of examination of dental evidence and the proper evaluation and presentation of dental findings in the interest of justice
- 5. FDI says… “ Thatbranch of dentistry which, in the interest of justice, deals with the proper handling and examination of dental evidence, and with the proper evaluation & presentation of dental findings ”
- 6. Where is itUsed Civil Criminal Research
- 7. Forensic Dentistry- AHistorical View Dates back 4500 years First Recording in 2500 BC
- 8. More on History •FATHEROF FORENSIC ODONTOLOGY DR.OSCAR AMOEDO • "The role of dentists in the identification of the victims of the catastrophe of the Bazar de la charite“ 1897 • L'ART DENTAIRE EN MEDECINE LEGALE 1898 - French 1899 - German
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- 10. Why Dentists? 10 PROCESS SAME AS THATUSED IN DENTAL PRACTICE RECOGNITION AND EVALUATION OF CERTAIN CHANGES OVER TIME CONTINUALLY COMPARE CURRENT AND PREVIOUS RECORDS
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- 12. Where and How? •Human Remains • Living Body Identification • Age and Sex determinationAge and Sex • Victim AnalysisMass Disaster • Bite • Lip Prints Marks and Prints
- 13. Why Teeth ? Hardestof all Human Tissues Resistant to post-mortem & destruction Contained in Small Area of the Body Most stable biological evidence Readily accessible for examination No two individuals have identical dentitions - UNIQUE Dental care rendered- UNIQUE Teeth as Sources for Forensic DNA
- 14. Tooth at DifferentTemperatures 200oC • Crown- Mottled • Root- Light yellow 300oC • Crown- Yellow Brown • Enamel- Cracks • Roots-Dark Brown, Destroyed 400oC • Crown- Dark Brown, Cracks and Splits 500oC • Enamel separates from the crown 800oC • Volume reduction • Carbonization
- 15. and Beyond 800OC<915oC Amalgam Fillings- Intact >915oC Gold Alloys Melt 1090oC Porcelain May Survive
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- 17. Locard’s Exchange Principle "EveryContact Leaves a Trace“ "with contact between two items, there will be an exchange." • The value of trace (or contact) forensic evidence was first recognized by Edmund Locard in 1910.
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- 21. UV Lighting forInspection
- 22. Comparison Microscope Allows twosections to be viewed simultaneously at exactly the same magnification so that a correlation can be tested between the two
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- 24. Introduction • For Dummies –Ante Mortem, Post Mortem • Ante- Before • Post- After • Mortem- Death • Dental Records – Instrumental in Forensic Odontological Identification • Record Content – Exhaustive, Correct and Clearly Expressed
- 25. Dental Records- Include Photographs IntraOral Radiographs Impressions Comparisons Study Models
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- 27. Principles of DentalIdentification Preliminary Evaluation Postmortem Examination Ante-Mortem Investigation & Data Collection Comparison and Conclusion Validation & Reliability
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- 29. Post Mortem DVI •Clinical examination • Post-mortem radiographs • Photographs • Charting and recording PINK FORM
- 30. Ante Mortem • Chartingand recording • Radiographs , models and photographs YELLOW FORM
- 31. Comparison & Conclusion DISCREPANCYBETWEEN THE TWO RECORDS COMPARED SHOULD HAVE AN EXPLANATION.
- 32. Comparing – Ante& Post Mortem POSITIVE IDENTIFICATION: • Sufficient Uniqueness , no major differences PRESUMPTIVE (POSSIBLE) IDENTIFICATION: •Certain common features, enough information missing to establish a positive identification INSUFFICIENT IDENTIFICATION EVIDENCE: • Insufficient supportive evidence EXCLUSION OF IDENTIFICATION EVIDENCE: • Either explainable or unexplainable discrepancies, which results in inconsistencies that prevent the establishment of any identification Exclusion may be just as important as determination of positive identification
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- 34. Identification of anIndividual Important to have ante-mortem records Age estimation Sex determination Race and folk groups Occupation , habits and social status Illness and medication
- 35. What Helps • Arrangement –Type – Rotated – Mal Occlusion • Mixed Dentition – Eruption Sequence
- 36. What Helps ARRANGEMENT OFTEETH: - Type - Rotated - Mal-Occlusion MIXED DENTITION: - ERUPTION SEQUENCE
- 37. MISSING TEETH: -Number andType of teeth missing MALSHAPED TEETH: - Fused DIASTEMA
- 38. HEREDITARY CONDITIONS: - Dentinogenesis -Amelogenesis - Malocclusion
- 39. TYPE OF TEETH: Macrodontia/Microdontia RESTORATION: -Type- Gold, Tooth colored, Amalgam, Porcelain - Area of restoration - Endodontic treatment
- 40. SUPERNUMERARY TEETH: ADDITIONAL CUSPS: -Cuspof Carabelli
- 41. Unusual Wear andTear Erosion Abrasion Unusual wear and tear can help identify various aspects
- 42. Habits • Staining ofTeeth – Pan Chewer – Betel Nut Chewing – Smoking • Pipe Smokers
- 43. Occupation • Goldsmith orperson working with lead shows blue line in gums • Green line – by Copper • Black line – by Silver • Cobbler, carpenters, electrician & tailors have central notch in the incisal edges of anterior teeth. • Traffic police & flute player has attrition of anterior teeth
- 44. Tooth loss beforeor after death • Empty Sockets – Unresorbed and Sharp - lost after death
- 45. Dentures – IdentifyIndividual • Different Properties of Dentures can be used – Type of Material – Marks and Names on dentures
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- 48. Systems for AgeEstimation • Dentition - one of the fourth system used in estimating physiologic age • Other three being – Bone development, – Secondary sexual characters, – Stature and weight.
- 49. Systems for AgeEstimation Dentition Bone development Secondary Sexual Characters Stature and Weight
- 50. Dentition for AgeEstimation Eruption Sequence Deciduous Mixed Permanent
- 51. Methods for AgeEstimation • Gustafson G. 1966 • Sopher IM. 1976 • Harvey 1976.
- 52. Gustafson’s Method • Ageestimation in adults over 21 yrs of age depends on the physiological changes in each of the dental tissues – Attrition – Paradentosis – Secondary dentin – Cementum apposition – Root resorption – Transparency of the roots
- 53. • Changes aremeasured in degrees 0-3 – 0 : No Change – 1 : Beginning of Changes – 2 : Obvious Changes – 3 : Maximum Changes • Formula for Estimation – Age = 11.43 + 4.56X – X- The degree of changes 53 Gustafson’s Method
- 54. Histological Study ofTransparent Dentine
- 55. Below 20 years21 – 30 years 31 – 40 years Transparent Dentine of Root < 20Y • ABSENT 21- 30Y • Attempted Formation in Apical 3rd 31-40Y • Involving full apical 3rd. 41-50Y • beyond apical 3rd up to middle 3rd of root 51-60Y • beyond middle of the root and towards cervical.
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- 57. Age Determination atDeath • Boyde – Works on the incremental lines of enamel – Very effective upto few months after birth This so-called neonatal line may be of extreme medico-legal importance in these cases
- 58. Pink Teeth • Dueto accumulation of blood breakdown products in the dentinal tubules • It appears to take from 7 to 14 days before discoloration becomes apparent • May give some gross indication of time of death • Violent death such as strangulation • In forensic practice the phenomenon is most frequently seen in victims of drowning
- 59. Other Methods ofAge Estimation • Teeth colour • Calcium/phosphate ratio • Number of dentinal tubules • Flourescence from dentin and cementum • Root canal shrinkage
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- 61. Traits for Sexdetermination TRAIT MALE FEMALE General size Larger Smaller Supraorbital ridges Medium to large Medium to small Architecture Rugged Smooth Orbits Square Rounded Cheek bones Heavier, more laterally arch Lighter & more compressed Mastoid process Large, prominent, roughened Smoother & less prominent Forehead Less rounded More rounded :
- 62. MALE FEMALE Lower jawMassive Less massive Chin Square Pointed and rounded Symphyseal height More less Angle region Averted Non- averted Lateral angle marked roughening or ridged appearance b’coz of masseter Attachment & powerful closing of jaws More rounded attachment surface more smoother Ramus Broad Less broad CONDYLAR ANGLE : Vary between male and female
- 63. Sex Determination- Dentition •Can be determined by dental pulp. • Davidson bodies in the nucleated cells of polymorph in pulp cavity • Saliva - cells are studied by Barr & Davidson bodies
- 64. 64 BARR BODIES –SEX CHROMATIN INFANT FEMALE ADULT FEMALE ( > 20) NOT SEEN IN MALE
- 65. AMELOGENIN • Amelogenin (CalciumBinding Protein) found in developing tooth enamel • Gen Females (XX) have two identical AMEL genes but the males (XY) have two nonidentical genes e - on both the Y chromosome in males and the X chromosome in females • ISOLATING GENOMIC DNA FROM DENTAL CELLS TO IDENTIFY GENE AMELOGENIN • Helps in sex determination
- 66. The Y-CHROMOSOME Nucleus ofmale cell with fluorescent ‘Y’ chromosome Nucleus of female cell with faint fluorescence of the whole nucleus
- 67. Amino Acid Racemisation . •Helfman and Bada first suggested a relationship between dentinal age and the extent of aspartic acid racemization in dentine. • Aspartic acid is an amino acid that has a rapid rate of racemization • Constant change in the ratio of L- and D-aspartic acid at different ages and this D-L ratio may be used for age estimation. • Racemization rate of aspartic acid is high in root dentine
- 68. Sex Estimation byTooth Size • Environment & population specific • INCISOR INDEX = MDI2 * 100 MDI 1 – Higher in males – Lower in females • MANDIBULAR CANINE INDEX = (mean m-d canine width in females + S.D.) + (mean m-d canine width in males – S.D.) 2 68
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- 70. CHINESE: 1.Wide arch 2.Enamel extension betweenroots of molars 3.Five cusped third molars 4.Rooted deciduous molars EUROPEANS: 1. Narrow arch & crowding 2. Cusp of Carabelli MONGOLOID: 1.Occlusal enamel pearls in premolars 2.Missing mand. incisors 3.Shovel-shaped incisors AMERICAN INDIANS: 1. Marked attrition 2. Shovel-shaped incisors 3. Large teeth SOUTH AFRICANS: Tall pulp chambers Significant Traits for Race
- 71. ABO Blood GroupDetermination • Different Methods Used – Absorption elution technique – MIXED CELL AGGLUTINATION TESTS – CELL AGGLUTINATION TESTS
- 72. Blood Group Substances •In Soft Tissues – Water-soluble ABH substances – Found in abundance in the mucous acini of salivary glands of secretors – Absent in serous acini of non-secretors – Restricted role due to putrefaction – Mixed cell agglutinations or Elution-absorption is used • Bone and Teeth – Resistance to putrefaction – Pulverization of the sample, extraction of the blood group substances using various solvents. – SOLVENTS: Processing the tooth powder with 1% HCl acid and alcohol, 20% EDTA and alcohol, Acetone extraction
- 73. The Luminol Reaction •Fluorescent Chemical – Can reveal blood stains when sprayed in dark on the suspected item – Sensitive to pickup minute blood trces
- 74. Saliva • Samples obtainedfrom cigarettes, bidi ends & utensils • Samples from victims as well as suspects in case of sexual crimes • Presence of saliva can be confirmed using - The starch-iodine test - Phadebas test BLOOD GROUP SUBSTANCES IN SALIVA: • ABH blood group substances in fairly high concentration seen especially in individuals of ‘O’ group (secretors) • Screening test with anti H • Tests for ‘A’ & ‘B’ substances using - Absorption-elution method for A, B, H (small samples) - Agglutination-inhibition (large samples)
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- 76. Bite Mark ‘a markmade by teeth either alone or in combination with other mouthparts’ Or ‘a physical alteration in a medium caused by the contact of teeth’
- 77. Classification • Cameron andSims (1974) – Non Human (animals) – Human • In food stuffs (e.g. in part eaten food stuffs abandoned by offenders at scene of crime). • On non-biological objects (e.g. Pencils, pipe stems, detonators) • In human skin • Non criminal (erotic bites) • Criminal (ordinary and sexual assaults) which may be • Offensive (upon victim by assailant). • Defensive (upon assailant by victim)
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- 79. Description of BiteMark Demographics Name of victim, Case Number, Date of examination, Referring agency, Person to contact, Age of victim, Race of victim, Sex of victim & Name of examiner(s) Location Anatomical location, Surface contour: flat, curved or irregular Tissue characteristics Underlying structure: bone, cartilage, muscle, fat, Skin: relatively fixed or mobile Shape Shape of the bitemark should be described; e.g. essentially round, ovoid, crescent, irregular, etc Color Color should be noted; e.g. red, purple, etc. Size Vertical and horizontal dimensions of the bitemark should be noted, preferably in the metric system. Type of Injury Petechial hemorrhage: Contusion (ecchymosis), Abrasion, Laceration, Incision, Avulsion, Artifact
- 80. Collection of Evidencefrom Victim Photography Name of victim, Case Number, Date of examination, Referring agency, Person to contact, Age of victim, Race of victim, sex of victim & Name of examiner(s) Salivary Swabbing Impressions Tissue Samples Tissue Fixative:10% Formalin is a common fixative Other Information
- 81. Collection of Evidencefrom Suspect History history of any dental treatment subsequent to, or in proximity to, the date of bitemark. Photography good quality extraoral photographs should be taken, both full face and profile. ABFO No. 2 scale should be utilized Intraoral photographs preferably would include: Frontal view , Two lateral views, Occlusal view of each arch, Any additional photographs Extraoral Examination Intraoral Examination Impressions Sample Bites Study Casts
- 82. Bite Marks onFood • Photograph • Wash Saliva • Send for blood grouping • Apply a lubricant on the food stuff • Pour Plaster on it • After drying remove the cast 82
- 83. Food Bite Marks-Process PVS polyvinyl siloxane impression Cotton Backing Dental Plaster Mix Impression
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- 85. Methods • Overlay Fabrication –Hand Tracings – Photocopy technique – Computer Scanner – Radiography – CT Scanning
- 86. Non Metric &Metric Analysis Non Metric Metric
- 87. Photography in BiteMarks • Visible Light Photography • Digital Photography • Non-Visible Light Photography – Ultra violet photography – Infrared Photography
- 88. Bite mark locatedon deceased victim’s abdomen using normal full-flash photography.
- 89. Same Bite Markusing ALI
- 90. Normal “room light”photograph of palm side of two-month-old infant victim of child abuse; bite mark pattern is almost indiscernable
- 91. Same bite markusing forensic light source at low-angle incident lighting. Note improved visualization of separations (striations) between teeth.
- 92. Black-and-white view ofabdominal bite mark exposed with fullspectrum room light bite mark using forensic light source at low-angle incident lighting. Note improved visualization of separations (striations) between teeth
- 93. • Epiluminescence microscopyis a dermatologic technique developed for evaluation of pigmented skin lesions • This technique, through rendering the stratum corneum translucent, can aid in the visualization and photographic documentation of bite marks Epiluminescence light microscopy (ELM) in Bite Marks
- 94. DNA in DentalIdentifications • Teeth- Excellent source of DNA • DNA Extraction – From calcified tissues by CRYOGENIC GRINDING METHOD and PCR analysis is done – "RFLP"- Restriction Fragment Length Polymorphism Technique • DNA Comparison – With known Ante-Mortem sample – Parent or sibling
- 95. Cryogenic Grinding- DNAExtraction
- 97. ANTE-MORTEM PAP SMEARPOST-MORTEM TEETH DNA PROFILE COMPARISON
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- 99. Scanning Electron Microscopy •The fragment of hard material found in the depths of a human bite mark consists of typical tooth enamel prisms, indicating that suspects with intact anterior teeth could not have been involved in the biting episode
- 100. Incremental Growth Patterns •Associated with minor changes in physiological activity during the laying down of the hard tissues of the tooth and are said to be unique to each individual
- 101. Drugs • Tetracycline causes discolorationof the developing teeth by binding to the hydroxyapatite crystals • Fluorescent in ultraviolet light • At least five independent courses of treatment can be seen as fluorescent lines in the dentine • the period of time elapsed between the individual courses of treatment can be estimated
- 102. Analysis of bodyfluids • Phosphoglucomutase (PGM) enzymes may be extracted from small fragments of dentine up to some months after death and can be typed using electrophoresis • Two different types of enzymes (1 and 2) are indicated by the stained bands and a PGM grouping which is different from that of a suspect will eliminate him or her from the enquiry
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- 104. Lip Prints • Tsuchihashinamed wrinkles and grooves visible on lips as 'sulci labiorum rubrorum’ • Imprint produced by these grooves termed 'lip print’ • Examination - 'cheiloscopy' • Grooves are heritable & are supposed be individualistic • Therefore, can constitute material evidence left at a crime scene
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- 107. Palatal Rugae • RugaePattern Unique to an Individual • Do not change shape with age and reappear after trauma or surgical procedures
- 108. Facial Reconstruction • ObtainSkull • Determine demographic information – (female, Caucasian, early 40s) • Note unique features – (had lost all back teeth on upper and lower jaw) • Anything known about this individual? – (came to U.S. by boat in 1710 from Europe, died and buried in NY around 1733)
- 109. Facial Reconstruction… • AddTissue depth Markers – Based largely on sex and race • Begin to add common fat deposits and underlying muscles
- 110. Add muscle toaverage depth for race Add skin, nose, ears Add features related to age and race (wrinkles, eye and hair color) Facial Reconstruction…
- 111. 7. Add clothingetc appropriate for the time period, religious affiliations, etc Facial Reconstruction…
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- 116. Information Technology • Commonlyused computer programs are: – The FBI-NCIC program based on the California Dental Identification system. – CAPMI (Computer Assisted Postmortem Identification) developed by US Army Institute of Dental Research. 116
- 117. Anti-Missile Technology • Maybe able to help in identifying dead bodies • Software was developed in Mexico, which recognizes the unique characteristics of a person's skull when applied to common x-rays • A computer working for the federal government was designing a computerized means to photograph incoming missiles at one thousand frames per second and identify them by specific characteristics within a split second • Bourgeois realized that this same technology could be used to find skull landmarks on X-ray films taken of the head • These lateral head films exist for “hundreds of thousands of individuals” who have had dental surgery or orthodontics • This new technique, with a good database, could have wonderful potential for the world of forensic
- 118. MASS DISASTER VICTIMS BODYPARTS VICTIMS RELATIVES BLOOD DNAANALYSIS DNAANALYSIS DNA PROFILE DNA PROFILE ALLELES ALLELES BA Alleles A and B same - body identified Alleles A and B different – body not identified DNA Profile in Mass Disaster
- 119. Conclusion • Forensic dentistryis still in its infancy and may be considered more of an art or craft than a science • It is important that for the development of forensic dentistry, practitioners retain a healthy degree of scepticism of their abilities • Proper records have to be maintained There is no more important lay audience than the jurors in a murder trial, and they must not be given the impression that the forensic dentist is a Sherlock Holmes or a Hercule Poirot
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