![DENTAL INDEX
In relation to absolute tooth size, tooth proportions have
been suggested for differentiating between males and
females.
RAO and associates developed “MANDIBULAR CANINE
INDEX”.
Aitchison presented the “INCISOR INDEX”
- Ii= [MDI 2/MDI 1] X 100,
- where MDI 2 is maximum M-D diameter of lateral incisor.
- MDI 1 is maximum M-D diameter of central incisor.](https://image.slidesharecdn.com/forensic-odontology1-240820062529-68afe912/85/INTRODUCTION-TO-FORENSIC-ODONTOLOGY-PART-1-63-320.jpg)
![ Mean and standard deviation (SD) of MCI was derived
separately for males and females and a cut off point to
distinguish the gender, termed STANDARD MCI was
calculated:
[(mean m-d canine dimension in female+ S.D.)+
(mean m-d canine dimension in males-S.D.)] / 2
Standard MCI value –acc to RAO and associates was
0.274
If the MCI value of skull specimen less than or equal to
standard MCI -female
If more-male
Success rate-86%](https://image.slidesharecdn.com/forensic-odontology1-240820062529-68afe912/85/INTRODUCTION-TO-FORENSIC-ODONTOLOGY-PART-1-64-320.jpg)
INTRODUCTION TO FORENSIC ODONTOLOGY- PART 1
- 1. FORENSIC FORENSIC ODONTOLOGY ODONTOLOGY PART-1 PART-1 Dr. Maya S Reader Dept of Oral and Maxillofacial Pathology
- 2. CONTENTS- PART-1 INTRODUCTION HISTORY DENTAL IDENTIFICATION UNCONVENTIONAL IDENTIFICATION DISASTER VICTIM IDENTIFICATION DENTAL PROFILING GENDER DETERMINATION
- 3. CONTENTS PART-2 DENTAL AGE ESTIMATION CRIME INVESTIGATION-BITE MARKS CHILD ABUSE
- 4. Forensic Odontology Forensic Odontology • Word “Forensic”- latin word Forum means “Court of Law”. • FDI defines it 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 Odontology is the application of dentistry in legal proceedings deriving from any evidence that pertains to teeth.
- 5. Scope of Forensic Odontology 1. Identifying unknown human remains through dental records & cranio-facial bones 2. Age estimation of both the living and deceased 3. Recognition and analysis of bite marks found on victims 4. Analysis of oro-facial trauma associated with person abuse 5. Determining the gender of an unidentified individual 6. Identification in mass fatalities 7. Eliciting the ethnicity from the skeletal remains 8. Analysis of dental malpractice claims 9. Presenting evidence in court as an expert witness
- 6. Historic mile stones in forensic dentistry • 1st dental identification was made between 49-66 AD • King William ; in 1066 AD was supposed to be the 1st to use bite marks for identification . • 1837- Dr Edwin Saunders established the eruption sequence . • 1897- Dr Oscar Amoedo (Father of Forensic Odontology ) wrote the first book of forensic dentistry “ → L’Art Dentaire en Medicine Legale”
- 7. History of Forensic Odontology • 66AD – First body identified using teeth- Lollia Paulina • Revolutionary War-Paul Revere was the first forensic dentist in the United States because he identified fallen revolutionary soldiers. • 1849 – Mass deaths at Vienna Opera House Fire-Dental evidence was first admitted into court system in US. • In 1967 Russian source reported that dental evidence was responsible for identification of badly charred bodies of Adolf Hitler & Eva Braun.
- 8. Organizations of Forensic Odontology Bureau of Legal Dentistry (BOLD) American Board of Forensic Odontology (ABFO) International Organization for Forensic Odonto-Stomatology (IOFOS)
- 9. IDENTIFICATION?? Identification is the establishment of person’s individuality. Requirement for proper identification of dead: 1. Both for legal and humanitarian reasons. 2. Property settlement. 3. Remarriages. 4. Allow cremation and burial of the body.
- 10. TRADITIONAL MEANS OF IDENTIFICATION Visual recognition Personal property Anthropometry Serology DISADVANTAGES: These methods are presumptive Present a series of general characteristics May not be unique
- 11. Safest option for identification is to analyze physical features present in body. Physical features may be inherited or acquired. Inherited features include racial characteristics. Acquired features may be surgical scars, previous fractures or dental restorations.
- 12. Dental Identity?? According to Acharya and Taylor, the Dental identity is defined as total of all the characteristics of teeth and associated structures which while not individually unique, when considered together provide a unique totality.
- 13. DENTAL IDENTIFICATION Why Teeth??? •Every human body ages in a similar manner, the teeth also follow a semi-standardized pattern. These quantitative measurements help establish relative age of person. Each human has an individual set of teeth which can be traced back to established dental records to find missing individuals. Teeth is made of enamel (hardest tissue of the body) so it can withstand trauma (decomposition, heat degradation, water immersion, and desiccation) better than other tissues in body. Teeth are a source of DNA: dental pulp or a crushed tooth can provide nuclear or mitochondrial DNA that helps to identify a person. The positive identification of living or deceased persons using the unique traits and characteristics of the teeth and jaws is a corner stone of forensic odontology
- 14. Individual Characteristics Size of tooth Shape of tooth Shape of root Placement of tooth Number of teeth Combinations of dental work done: Crowns Extractions Bridge Fillings Root canals Various dental work
- 15. Basis for Dental Identification • Human dentition is never same in any two individuals • The morphology and arrangement of teeth vary from person to person • Teeth are relatively resistant to environmental insults after death
- 16. Dental Identification Procedures Two forms:
- 17. Comparative Dental Identification Includes four steps:
- 18. POSTMORTEM DENTAL EXAMINATION It is conducted at mortuary under the authorization of forensic medical examiner. First step is visual appraisal of the dead body. The body bag should be searched thoroughly for any teeth or appliances. All the features like missing, caries ,restorations, attrition, rotation and occlusion should be recorded and entered in Interpol Postmortem dental form.
- 19. Systematic protocol starting with critical examination of the external features of the body such as gender, ethnicity, build, wounds, scars, tattoos and body piercing. Photographs, radiographs, finger prints, fingernail scrapings and hair sample are then collected. Oral examination is an essential part of the post mortem procedure. The forensic dentists who conducts oral autopsy should have adequate knowledge about common post mortem findings such as Rigor mortis, Livor mortis, Decomposition, and post mortem artifacts.
- 20. Rigor Mortis is a state of stiffening of muscles render the jaws rigid and the use of mouth gags or intra oral myotomy is essential for jaw separation. Teeth may become brittle in burned cases, they need to be reinforced with Cyanocrylate cement, polyvinyl acetate or clear acrylic spray paint prior to examination. According to Griffith and Bellamy, access for radiography in incinerated bodies can be obtained by removing tongue and floor of the mouth by tunneling fashion from beneath the chin.
- 21. A thorough examination of soft tissue injuries, fractures and presence of foreign bodies is under taken and samples of hard and soft tissues should be obtained All post mortem information pertaining to the body must be entered on to the standard ‘Interpol Post mortem Form’ which is color coded in pink.
- 22. OBTAINING ANTE-MORTEM (AM) RECORDS Dental records contain information of treatment and dental status of a person during his / her life may be obtained from the treating dentist, specialist or hospital records. Original records should be examined. Such records may be in the form of dental charts, Radiographs, casts, photographs, etc., The contents of all available dental records should be transcribed onto the standard ‘Interpol Ante-mortem Form’ which is color coded in yellow.
- 23. COMPARING POST AND ANTE -MORTEM DENTAL DATA Once the post mortem evidence and dental records are available, the data can be compared Features compared include tooth morphology and associated bony structures, pathology and dental restorations An individual with multiple dental treatment and unusual features has a better likelihood of being identified Comparison should be qualitative rather than quantitative in nature.
- 24. REPORT AND CONCLUSION On comparison of AM and PM data, a range of conclusions can be reached: Positive identification - indicates that AM and PM data match each other -Identity is proven “beyond reasonable doubt”. -It usually includes radiographic support. Probable identification -Where the data is consistent but a lack of quality PM/AM information means one cannot arrive at a positive identification. -There is high level of concordance between AM and PM information but usually no radiographic support.
- 25. Possible identification - wherein the available information is insufficient for a positive identification but the identity cannot be excluded either. Exclusion of identity - In which AM and PM data are clearly inconsistent. - The data contains unexplainable differences that indicate a mismatch.
- 26. UNCONVENTIONAL IDENTIFICATION Where comparative dental identification is not possible these may be applicable:
- 27. SKULL SUTURE PATTERNS - Patterns produced by cranial sutures are highly variable and individualising. - Sutures commonly used for identification are the coronal, saggital and lambdoid. - Various sutural configurations: Serrated Denticulate Squamous Limbous Plane Visible on routine diagnostic radiographs such as antero posterior , lateral views
- 28. 2. FRONTAL SINUS CONFIGURATION -Insignificant during early stages of life -Increases in size and complexity with age and attains max size at abt 20 years 3. FACIAL RECONSTRUCTION -A 3-D representation of facial structures is produced using the skull as the foundation. -Skull cavities are blocked with modelling wax. -Impression of skull is made with rubber base impression materials and cast is poured with plaster -Disadvantages: - time consuming -variable success rate - highly subjective
- 30. Superimposition methods When lack of dental records is there, superimposing the facial photograph and skull has been advocated Since anterior dentition is usually visible, use of tooth size, shape, angulations may be of particular relevance Photographic superimposition Disadvantages: - angular positioning-the skull and the facial image should have reasonably equal horizontal and vertical angulations. - Camera object distance- differences in the focal lengths of camera lens can alter the contour of high curvature areas - -poor initial photography-inferior camera and film quality can result in poor quality photographs.
- 31. VIDEO SUPERIMPOSITION Advantage over photographic superimposition Positon of the skull can be altered Video mixers enable added advantage of fade-in, fade- out horizontal and vertical “sweep” mechanisms. It allows different images to be progressively superimposed upon each-other
- 32. DIGITAL SUPERIMPOSITION Newer trends used. AM photographs is digitised to produce a 2-D image Skull is laser scanned to produce 3-D image The 2-D digitised AM image is then projected onto the 3-D skull image and the anatomical landmarks are compared.
- 33. LIP PRINTS Examination of lip prints- “cheiloscopy” The lines and fissures of the lips have individual characteristics similar to fingerprints Can be used in identification Genetically determined Remain unchanged from birth Tsuchihashi named the wrinkles and grooves on lips- “sulci labiorum rubrorum”
- 34. CLASSIFICATION - Lip prints were first classified by Santos as: a) Simple wrinkles Straight line Curved line Angled line Sine-shaped curve b) Compound wrinkles Bifurcated Trifurcated Anomalous
- 35. According to Tsuchihashi : Type I- Clear- cut vertical grooves that run across the entire lip Type I’-Similar to type I, but do not cover the entire lip Type II- Branched grooves Type III- Intersected grooves Type IV- Reticular grooves Type V- Grooves that can not be morphologically differentiated
- 36. - Invisible prints can be lifted using materials such as aluminum powder, magnetic powder DISADVATAGE: 1. Trauma, pathosis, surgical treatment can affect the size and shape of the lip 2. The zone of transition close to vermilion border is extremely mobile so prints produced may differ depending on pressure applied and its direction
- 37. Different Patterns of Lip Prints Lip Prints.(Cheiloscopy),IJDR,10: 234-237,2001.
- 38. PALATAL RUGAE Examination of Palatal Rugae- “Rugoscopy”. Palatal Rugae are well protected by the lips, cheeks, tongue and the teeth in incidents of fire and high impact trauma. Rugae patterns do not change with age and reappear after trauma or surgical procedures. They may be a reliable source of identification, especially in cases of edentulous individuals.
- 39. CLASSIFICATION Given by Lysell, based on length: 1. Primary rugae (>5mm) 2. Secondary rugae (3-5mm) 3. Fragmentary rugae (2-3mm) (<2mm is not taken into consideration) By Kapali and associates, based on shape: 1. Straight 2. Wavy 3. Curved 4. Circular
- 40. According to Thomas and Kotze: 1. Branched 2. Unified 3. Cross-linked 4. Annular 5. Papillary
- 42. SCANNING ELECTRON MICROSCOPY Used for detailed study of surface configuration , tooth morphology , fracture surfaces and restorations. Provides a highly magnified, 3-D image of minute surface structures. In one case- SEM detected micro serrations produced by dental drill in an incinerated tooth- establishing presence of a prepared cavity. Presence of fissure sealant in another case- assisted in positive identification of individual.
- 43. DNA ANALYSIS Teeth are excellent source of DNA material. DNA is made use only when conventional dental identification fails. PCR allows for amplification of DNA-popular with forensic investigators. DNA extracted from teeth of a deceased-compared with known AM sample, to a parent or sibling. AM sample- stored blood, hairbrush, biopsy specimen.
- 44. Precise method for identification Very time consuming and expensive process Very technique sensitive with contamination problems Usually match victim samples with samples taken from personal items or from known relatives Essentially 2 types of DNA: -Nuclear DNA -Mitochondrial DNA
- 45. Nuclear DNA commonly used- forensic cases. Method to obtain genomic DNA from teeth- “cryogenic grinding”. mitochondrial DNA(mtDNA)has an advantage –each cell has a high number of mitochondria ,so high mtDNA Hence can be substituted when nuclear DNA is unavailable. Cryogenic grinding
- 46. mtDNA is maternally inherited, thus same DNA pattern observed among maternal relatives. Due to exclusive maternal inheritance, can be used in identification in gap of several generations.
- 47. DNA EXTRACTION : Proposed by Sweet and Hilderbrand 1.CRYOGENIC GRINDING: The whole teeth is subjected to extreme low temperature using liquid nitrogen and then grinded. Disadvantage: whole teeth is lost. 2.Proposed by Trivedi and associates DNA was isolated by opening root canal and extirpating the pulpal tissue with some instrument and DNA was extracted. Advantage: tooth morphology is preserved .
- 48. DISASTER VICTIM IDENTIFICATION Disasters refer to events natural (earthquakes ,tsunami, floods, landslides) or manmade (air crashes, train accidents) that result in multiple human fatalities. Such events require identification of the individual due to severe mutilation of remains. Dentition being more resistant structures aid in establishing identity. It includes comparing hundreds of AM and PM data.
- 49. MAJOR PROBLEMS Some major problems encountered in a disaster include: Large number of human remains Fragmented, commingled, burned remains Insufficient PM remains Acquiring relevant dental records Legal, jurisdictional and political issues Less organization and communication
- 50. Forensic dentists along with fingerprint experts and other identification teams are part of the identification commission. Dental identification is one of the most successful methods of identification in disasters, approximating 50% . Therefore, most disasters have a DVI dental section . The DVI dental section is divided into three sub- sections: 1. Ante- Mortem dental unit. 2. Post- Mortem dental unit 3. Dental comparison unit
- 51. Ante Mortem Dental Unit TASKS OF AM UNIT They need to collect as much information as possible in shortest period of time. Determine who is involved in disaster. Locate and procure ante mortem records. Develop an AM composite for each victim.
- 52. Personnel in this unit should be capable of reading and interpreting all dental records provided. The quality, quantity, and variety of dental record present the major obstacle to this unit. Transcribing and copying could reduce the quality of AM information. All information obtained must be transferred onto a standard (INTERPOL)AM form.
- 53. Post Mortem dental unit The dental examination is done usually after most other procedures (general photography, fingerprinting, medical autopsy, etc), which gives sufficient time to set up base. Equipment such as portable dental radiography apparatus should be set up at a convenient place within the temporary mortuary Need to arrange for photography of teeth. This unit will also be responsible for processing of radiographs.
- 54. DENTAL COMPARISON UNIT Comparison and identification should begin once all the PM information is available. It may be done manually or by computer aid. Computer software programs such as IDENTIFY,ODONTID, TOOTHPICS,CAPMI etc, can be used. The final identification is always done by the dentist, based on personal evaluation of evidence. The INTERPOL guide states that the success of DVI depends upon the active participation of different identification teams. Therefore, its reciprocal in nature and adds to the SUCCESS of DVI.
- 55. DENTAL PROFILING -Triad of information ETHNIC ORIGIN GENDER AGE
- 56. ETHNIC ORGIN Human species Sub-saharan-negroid Sahul-pacific Australians,fiji Western Eurasia- Europe,middle east Sunda-pacific South east asia,new-zealand Sino-american- mongoloids North east asia S America
- 57. Dental features Metric features –tooth size(eg-lack of space in jaw leads to compressed teeth) Non metric features-tooth shape NON METRIC FEATURES- “Shovelling” HIGH-Sino-american INTERMEDIATE-Sunda pacific LOW-others “Carabelli’s” feature- High-Western eurasia Low-Sino american Intermediate-others Shovel-shaped incisors and the Cusp of Carabelli are both dental indicators for ethnicity
- 58. More than 30 non metric features- Richard Scott and Christy Turner II.
- 59. European / West & South Asians- 4 cusped lower-2nd molars, Two rooted-Lower canine, 3 cusped upper 2nd molar East Asians- •Shovelling, •3 rooted lower 1st molars, •3 cusped upper-2nd molars •Single rooted lower 2nd molars
- 60. GENDER DETERMINATION Determining the gender from unknown skeletal remains - 2ND step in building the dental profile of the deceased. Gender determined from : - METRIC FEATURES OF THE TEETH - MORPHOLOGY OF SKULL BONES AND MANDIBLE - DNA ANALYSES OF TEETH
- 61. METRIC FEATURES OF TEETH Teeth maybe used for differentiating gender by measuring their MD and BL dimensions. Male teeth are larger. Studies show significant differences between male and female permanent tooth crown dimensions. Tooth measurements are population specific and vary from region to region.
- 62. The canines have maximum differences in most studies. Anderson and Thompson 1973, observed that mandibular canine width and inter-canine distance were greater in males than females and permitted a 74.3% correct classification of gender. Hence regarded as most “dimorphic teeth”. Female canine are narrower BL and more pointed.
- 63. DENTAL INDEX In relation to absolute tooth size, tooth proportions have been suggested for differentiating between males and females. RAO and associates developed “MANDIBULAR CANINE INDEX”. Aitchison presented the “INCISOR INDEX” - Ii= [MDI 2/MDI 1] X 100, - where MDI 2 is maximum M-D diameter of lateral incisor. - MDI 1 is maximum M-D diameter of central incisor.
- 64. Mean and standard deviation (SD) of MCI was derived separately for males and females and a cut off point to distinguish the gender, termed STANDARD MCI was calculated: [(mean m-d canine dimension in female+ S.D.)+ (mean m-d canine dimension in males-S.D.)] / 2 Standard MCI value –acc to RAO and associates was 0.274 If the MCI value of skull specimen less than or equal to standard MCI -female If more-male Success rate-86%
- 65. MORPHOLOGY OF SKULL BONES Orbits- squared, rounded margins Nasion-depressed Size is larger MALE FEMALE Smaller size Slightly developed Rounded,sharp margins Rarely depressed Supraorbital ridge-well developed
- 66. •Glabella-markedly curved •Mastoid process-large •Forehead-sloping •Nasal aperture- High and narrow •Palate-large,U-shaped •Foramen magnum-large and long •slightly curved •Small •Straight •Low and broad •small,parabolic •small and round MALE FEMALE
- 67. MANDIBULAR FEATURES Bigger, broader ascending ramus Condyle-larger Shape of chin- square Gonial angle-less obtuse Body height- greater depth at symphysis smaller, narrow ascending ramus smaller rounded or pointed more obtuse shallow MALE FEMALE
- 68. GENDER DETERMINATION BY DNA ANALYSIS Amelogenin (AMEL)-major matrix protein secreted by ameloblasts of enamel. AMEL gene is located on X and Y chromosome in humans. It has a different signature with size and pattern of nucleotide sequence in males and females. Females-XX have 2 identical AMEL gene Males-XY have 2 non-identical genes. (Hanaoka and Minaguchi 1996)
- 69. Sex determination using Barr Bodies Barr et al 1950, the X-chromatin and intranuclear structure is known as Barr body. It is present as a mass usually lying against the nuclear membrane in females. Up to period of 4 weeks after death,gender determination can be accurately done from study of X and Y chromosomes.
- 70. Whittaker et al 1975, reported gender determination from necrotic pulp tissue stained by quinacrine mustard using a fluorescent Y- chromosome test, can be done with high accuracy. Duffy et al 1991, showed Barr bodies of X- chromosome and F bodies of Y-chromosomes can be preserved in dehydrated pulp tissues and that these pulp tissues retain their gender diagnostic characteristics for a minimum of 1 year.
- 71. REFERENCES Forensic Odontology-Paul G Stimson Textbook Of Oral Pathology-Shafers Oral And Maxillofacial Pathology-Neville Evidence Based Forensic Dentistry- Balwant Rai and Jasdeep Kaur A look at forensic dentistry —Part 1: The role of teeth in the determination of human identity. British Dental Journal, volume 190, no. 7, april 14, 2001.