2017-18 III BDS FORENSIC ODONTOLOGY.pptx

2017-18 III BDS FORENSIC ODONTOLOGY.pptx

1. FORENSIC ODONTOLOGY

2. INTRODUCTION: FORENSIC FORENSIS(Latin) Derived from Pertaining to forum Odontology refers to study of teeth FDI Defined it as “that branch of forensic medicine which in the interest of justice, deals with the proper handling and examination of dental evidence and also with proper evaluation and presentation of dental findings.”

3. Historical Evidence 66AD – First body identified using teeth: Lollia Paulina

4. Dental evidence played a vital role in historical case of identification of Adolf Hitler .

5. Recently in Nirbhaya case suspects were confirmed, by Dr. Ashith Acharya using bite marks. The decision on juvenility of Mohammed Ajmal Kasab was also identified on the basis of available dental records.

6. Why teeth in forensic??? Each human has an individual set of teeth. Teeth are made of enamel which can withstand trauma better than other tissues in the body. Teeth are the source of DNA-dental pulp.

7. Reasons For Identification Of Human Remains Criminal Marriage Monetary Burial Social Closure

8. Forensic odontologists delve into: Identifying unknown human remains. Victim’s identification in mass disaster. Eliciting the picture of life style and diet of skeletal remains. Assessing sex of skeletal remains. Age estimation of both living and deceased. Analysis and identification of bite marks at crime scenes.

9. PERSONAL IDENTIFICATION Identification is the establishment of a person’s individuality. Required for legal and humanitarian reasons. TRADITIONAL METHODS included: Visually recognizing body. Personal property such as clothing, jewellery, etc.

10. 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.

11. DENTAL IDENTIFICATION PROCEDURES TWO FORMS: Comparative identification Reconstructive identification (dental profiling)

12. COMPARATIVE DENTAL IDENTIFICATION INCLUDES FOUR STEPS: Step 1: Oral Autopsy Step 2: Obtaining dental records Step 3: Comparing post mortem and ante mortem dental data Step 4: Writing a report and drawing conclusion

13. ORAL AUTOPSY Also known as necropsy or post mortem examination. 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.

14. Photographs, radiographs, fingerprints, finger nail scraping and hair sample may be obtained according to the requirements Oral examination is an essential part of post- mortem procedures

15. A forensic dentist who conduct oral autopsy should have adequate knowledge about common post-mortem findings such as rigor mortis, livor mortis, decomposition and post-mortem artifacts. Rigor mortis may render the jaw and the use of mouth gags is essential for jaw separation.

16. Teeth - brittle in burned cases. Access for radiography in incinerated bodies. Status of each tooth. A thorough examination of soft tissue injuries, fracture and presence of foreign bodies.

17. All information pertaining to the body must be entered on to standard ‘Interpol post- mortem form’, which is color-coded in pink.

18. OBTAINING DENTAL RECORDS   Dental records contain information of treatment undergone and dental status of a person during life. Obtained from treating dentist, specialist, hospital records in the form of dental charts radiographs, casts, and/or photographs.

19. Content of all available records should be transcribed on to the standard ‘Interpol ante mortem form’ which is color coded in yellow.

20. COMPARING POST-MORTEM & ANTE-MORTEM DENTAL RECORDS   Features compared include tooth morphology and associated 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 characteristics. Comparison should take in to account quality rather than quantity.

21. WRITING A REPORT AND DRAWING CONCLUSION Positive identification Probable identification Possible identification Excludes identification Insufficient information

22. IDENTIFICATION IN DISASTERS

23. IDENTIFICATION IN DISASTERS The term "mass disaster" evokes images of a chaotic event. The process of dental identification is same except the magnitude of event is far greater. Mass disasters can be classified in one of three ways: Natural Accidental Criminal Large number of human remains Fragmented and Incinerated or commingled Tsunami in 2004.

24. DENTAL SECTION  According to Clark, 50% of identification are from dental evidence. So odontology is a part of team. Clarke states- ‘dental examination is usually done after most other procedures such as photography, fingerprinting, and autopsy’ Postmortem unit is responsible for processing the radiograph and also need to arrange photography of teeth. Antemortem unit is most difficult. Dentist need to collect as much information as possible in the shortest period of time  Comparison by- IDENTIFY, ODONTID, CAPMI, IDIS software .

25. IDENTIFICATION FROM DENTAL DNA Teeth can resist extreme condition. Researches state that teeth are an excellent source of DNA Applied technique → polymerase chain reaction- allows amplification of highly degraded DNA.

26. This facilitates comparison with a known biological antemortem sample of the decedent such as hair from a comb, epithelial cells from a toothbrush or biopsy specimen. Advantage: - DNA pattern can be compared to the parents or siblings, thus facilitating positive identification.

27. Types of DNA Pretty and Sweet pointed out 2 types of DNA: Genomic or Nuclear DNA: located in the nucleus of a cell and commonly used in nuclear studies. Mitochondrial DNA: present in the mitochondria of cells.

28. Extraction of dental DNA • Tooth pulp is considered as the best source of dental DNA. • Ajayprakash and co-workers isolated DNA from dental pulp and accurately determined personal identity using HLA-DQ amplification.

29. • Advocated by Sweet and Hildebrand. Technique: cooling the whole tooth to extremely low temperatures using liquid nitrogen mechanically grinding it to fine powder sufficient amount of DNA (intact, carious as well root-filled teeth). Disadvantage : - tooth needs to be completely crushed Cytogenic grinding

30. less destruction method for DNA isolation. opening of the root canals scraping the pulp area with a notched medical needle subsequently flushing of the tissue debris. This authors claim, ‘retains the morphology and physiology of the tooth.’ According to Trivedi and coworkers

31. • Palatal rugae are ridges on the anterior part of the palatal mucosa on each side of the mid-palatal raphe behind the incisive papilla. • RUGOSCOPY is a useful method of identification in edentate individuals. • The rugae pattern on the deceased’s maxilla or maxillary denture may be compared to old dentures. • well protected by lips, check, tongue, buccal pad of fat and teeth in incident of fire and high impact trauma. PALATAL RUGAE IN IDENTIFICATION

32. Can resist decomposition to an extent Unique to an individual. Seldom change shape with age and reappear after trauma or surgical procedures. Classification of palatal rugae: Acc to lysell, • Primary rugae (>5mm) • Secondary rugae (3-5 mm) • Fragmentary rugae (2<3 mm) • (Rugae <2 mm is not taken into consideration).

33.   • Thomas and Van Wyk traced rugae patterns from dentures on to clear acetate and then superimposed these tracings on photographs of plaster models. • Limson and Julian analyzed rugae pattern by a computer software and obtained 97% accuracy. • Ohtani and coworkers suggests - high accuracy can be obtained using straight forward visual comparison from dentures. Analysis of rugae pattern

34. Patterns of palatal rugae: (a) curved (b) wavy (c) straight (d) undetermined

35. DENTAL PROFILING

36. Dental Profiling :- It is the study of teeth and the surrounding tissues of the oral cavity for the purpose of establishing the identity of the victim Identifying the Ethnicity from Teeth Dental Age Estimation Gender Differentiation

37. Identifying the Ethnicity from Teeth The recommended approach for this is to evaluate non-metric dental traits, defined in terms of presence or absence of particular feature. More then 30 non-metric traits of the tooth crown and root have been analysed. Studies conducted on Indian population include only a few select traits. (Vijapure et al, Angadi and Acharya) Viz. Shovelling Carabelli’s Trait Three-Cusped Maxillary Second Molar Winging Cusp 5 Cusp 6 Cusp 7

38. Shovelling It refers to degree of prominence of mesial and distal marginal ridges on the lingual surface of the maxillary and mandibular anterior teeth.

39. Carabelli’s Trait It is a Cingular derivative expressed on the mesiopalatal or palatal aspect of the miso palatal cusp of maxillary molars. It is reported to be present in 26% of Indian population .

40. Three-Cusped Maxillary Second Molar Distopalatal cusp tends to be reduced size or absent on the second molar

41. Winging It is characterized by the bilateral labial rotation of the distal margins of maxillary central incisors. Incisal edges, taken together appears ‘V’ shaped from the occlusal aspect In was observed in 16% of Indian population.

42. CUSPS CUSP 5 – It is characterized by presence of occlusal tubercles on the distal marginal ridge of maxillary molars. An incidence of 75% is observed in Indians. CUSP 6 – An additional cusp between distal and distolingual cusp of mandibular molars. 57% of Indians have been shown to exhibit this feature.

43. CUSP 7 – An additional cusp between lingual cusps of mandibular molars. Seen in 21% of Indian.

44. Gender Differentiation Gender can be assessed based on morphology of

45. Gender identification from Craniofacial morphology and Dimensions Williams and Rogers observed – constellation of just six traits gives 94% of accuracy in gender determination Mastoid process Size and Architecture of skull Nasal Aperture Gonial angle

46. Extension of zygomatic arch beyond the external auditory canal Supraorbital ridge

47. Saini and co-workers found that using mandibular feature called ramus flexure produced accuracy rate up to 82.1%

48. Gender Differences in Tooth Size Teeth may be used for differentiating sex by measuring their mesiodistal(MD) and buccolingual(BL) dimensions. Male dentition is statistically larger than the female permanent n deciduous tooth crown dimensions. Gender is determined from tooth measurement using statistical methods called discriminant function analysis and logistic regression analysis.

49. Gender Determination by DNA Analysis It gives highly accurate results. Gender can be determined with very minute quantities of DNA and from very old specimens of teeth. Amelogenin (AMEL), matrix proteins secreted by the ameloblasts of the enamel. The AMEL gene, coding for this protein is located on the X and Y chromosomes in humans. Thus the females (XX) have two identical AMEL genes Male (XY) have two non-identical genes.

50. DENTAL AGE ESTIMATION

51. DENTAL AGE ESTIMATION Dental age estimation is final step of dental profiling after identifying the ethnicity tooth and gender differentiation It has application in post-mortem, reconstructive identification as well as living individual whose chronological age is disputed Dental age is uniformly applicable from infancy to late adolescence Dental age estimation is grouped in three phase 1] Prenatal,neonatal,and early postnatal period 2]Children and adolescent 3] Adults

52. Age estimation in prenatal, neonatal and early postnatal period The primary teeth is calcified at period of 12-14 weeks in utero and enamel formation is completed by first year and first eruption of tooth by time 6 months The neonatal line – is indicator of live birth By dry weight mineralization tooth ( at 6 month IU 60mg, new born 0.5mg, 6 month postnatal 1.8g) this method was developed by stack It give most accurate age estimation

53. Age estimation in children and adolescent Two events that use to measure dental age is tooth eruption and tooth calcification DECIDIOUS TEETH : emergence genetic control 6months -2.5yr Permanent teeth under influence of the intra oral environment, affected by infection , arch space and premature tooth loss METHODS : 1) Tooth calcification 2)Demirjian’s method 3) Value of third molar

54. TOOTH CALCIFICATION Evaluation of radiograph to asses tooth calcification is much better alternative since : calcification can be observed from radiograph for period of several year it is not altered by local factor the study of tooth calcification also let us access age at period when no emergence takes place ( 2.5 – 6 yrs and > 12 yrs )

55. DEMIRJIAN’S METHOD

56. VALUE OF THIRD MOLAR Valuable indicator of age group of 16-23yrs When all four third molar have completed calcified the chances of individual being 18yr old is 96.3% in male and 95.1% for female Lower third molar is usually best indicator of wheatear individual is 18yr old 7

57. AGE ESTIMATION IN ADULTS Age estimation in adult are influenced not only by age of individual but also by numerous endogenous and exogenous factor such as disease ,nutrition and physical strain METHOD: 1) Gustafson’s method 2) Dentin translucency 3) Incremental line of cementum 4) Radiographic method of Kvaal

58. GUSTAFSON’S METHOD In 1950 Goasta Gustafson : age estimation based on morphological and histological changes of teeth Method assessed changes such as: 1) Attrition (A) 2) Secondary dentin deposition (S) 3) Apical migration of periodontal attachment (P) 4) Cementum apposition at the root apex (C) 5) Root resorption at the root apex (R) 6) Root dentin translucency (T)

59. Gustafson’s assigned four grade ranging from 0 to 3 tooth can have any four grade for variable Age was estimated using formula AGE = 11.43+(4.56 x X) { X =total score obtained } Gustafson’s method was modified by Johanson in his formula instead four there were seven grades namely 0,0.5,1,1.5,2,2.5,3 AGE = 11.02+(5.14xA)+(2.3xS)+(4.14xP)+(3.71xC)+(5.57xR)+(8.98xT)

60. ROOT DENTIN TRANSLUCENCY Root dentin become translucent in third decade of life beginning from apex and advancing towards CEJ Decrease diameter of dentinal tubules Increase in intra tubular calcification Increase translucency Bang and Ramm –Root translucency increases with age Acharya develop formula for age estimation in Indians using translucency is as follow AGE=33.39+(2.812xT)

61. AGE ESTIMATION FROM INCREMENTAL LINES OF CEMENTUM Kagerer and Grupe – acellular cementum incremental lines are used in age estimation Mineralized unstained cross section of teeth preferably mandibular central incisor and third molar is used Author claims a ccuracy to within 2-3 years of actual age Hypomineralised bands in the incremental line – indicate pregnancy, skeletal trauma, and renal disorder which can be related to person life history facilitating identification

62. RADIOGRAPHIC METHOD OF KVAAL Kvaal and associates developed method that used the pulp size measurement of six teeth Maxillary – central incisor, lateral incisor and second molar Mandibular – lateral incisor , canine and first molar AGE= 33.5-18.6(M)-3.49(W-L)

63. CRIME INVESTIGATION

64. CRIME INVESTIGATION It includes : Bite marks Child abuse Lip print

65. Classification of Bite Marks: A. Cameron And SIMS Classification: This is based on the type of agent producing the bite mark and material exhibiting it. 1. Agents: a) Human b) Animal 2. Materials: a) Skin, body tissue b) Food stuff c) Other materials

66. B. Mac Donald’s Classification: a) Tooth Pressure Marks: b) Tongue Pressure Marks: c) Tooth Scrape Marks: 71 . 72.  73.  74.  . 75. 76.  77.  78.  I 79. 80. 81. 82. 83. 84. 85. 86. 87 88. 89 90.  91. 92 93.  94 95.  96. 97

67. Webster’s–foodstuff- theft/robbery Type 1- food item fractures readily-limited tooth penetration eg- hard chocolate Type 2- considerable food penetration eg- apple & other firm fruits Type 3- complete penetration of food item with slide marks-eg cheese

68.   Description of some types of bite marks Sexually Oriented bites- inflicted slowly and deliberately with suction applied to the tissue by tongue and lips. exhibits central or peripheral "suck marks" and marks of- anterior teeth with good definition. Child abuse cases: In the child abuse cases either aggressive (anger bite marks) or sexually oriented type of bite marks are seen

69. Self inflicted bite marks: Mostly found on the forearms of children caused by themselves. Mentally retarded and psychologically disturbed people may also inflict bite on themselves. Lesch-Nyhan syndrome, a X-linked, recessively transmitted disease with insensitivity to pain.

70. Identifying injury as a bite mark Gross feature: circular/elliptical mark - upper & lower arch -central area ecchymosis - sucking action Class features: differentiate b/n tooth type -incisors – rectangular -canines – triangular - premolars + molars – spherical/point shaped - Depends on attrition Individual features: fractures/rotations/spacing

71. Sites of bite marks Females are usually bitten - breasts, abdomen, thighs, buttocks and pubis, while Men are usually bitten - back, arms, shoulders, chest and penis. In cases of self-defense- the victim can bite on the hands and arms of an assailant.

72. Factors influencing the bite marks:   Type of tissue:  loose or with excessive fat - bruising leading to poor definition.  Fibrous tissue or with high muscle content - bruise less, definition is good. Age: Infants and old individuals bruise more than other age groups. Sex: Females tend to bruise more than males. Once produced bitemarks will be evident for longer period of time in females compared to males.

73. Medical status- bleeding disturbances, under anticoagulant therapy, skin diseases → bruise more. Time: Depression produced in the skin due to bitemarks will recover within 10-20 minutes leaving swelling and discoloration. After death, skin tends to contract, harden and decompose

74. 1. Description of bite marks. 2. Collection of evidence from the victim. 3. Collection of evidence from the suspect. 4. Bite marks comparison. Bite mark cases have to be dealt step by step in the following way:

75. I. Description of bite marks: Both in the living and deceased victims the following vital information should be recorded. Demographics: Name age Sex race case number date of examination and name of the examiners should be recorded. Location of the bite mark: • Anatomic location, contour - flat, curved or irregular and state the tissue characters • Skin - fixed or mobile. • Underlying tissue - bone, cartilage, muscle or fat.

76.   Shape of the bite marks: • round, ovoid, crescent or irregular in shape. Color of the mark: Size of the mark: • Both vertical and horizontal dimensions should be recorded in metric system Type of injury: • Petechial hemorrhage, Contusion, Abrasion, Laceration, Incision, Avulsion.

77.   II. Data collection from the victim: • Steps in the examination of the victim: A. Visual Examination- Type of injury, Contour & texture, Physical appearance (color and size), location • If the victim is dead, visual examination must be done before an autopsy. B. Photographs of the bite marks should be made immediately. 1. Orientation photographs 2. Close-up photographs   C. Salivary swabbing: • Saliva deposited on skin may have WBCs and sloughed epithelial cells which may be a source of DNA, enabling direct link to the suspect D. Impression of bite marks

78.   III. Examination of the suspect: • History of dental treatments after or just before the bite mark has to be noted. Photographs: • Full face, frontal, occlusal and lateral views of the dental arches should be taken. Examination: TMJ status Facial asymmetry Muscle tone Maximum opening of mouth Deviation while opening and closing movements Tongue movements Periodontal status should be noted Special attention should be given to the arrangement of dentition. Saliva swabbing should be performed Upper and lower dental models should be prepared .

79.   IV. Evaluation of evidence • While evaluating the bite mark first the cause of the mark has to be determined, since bite marks may be caused by nonhumans or humans.

80. HISTOPATHOLOGICAL CHANGES IN BITE MARKS Stage 1 –0 to 18 hrs – Scab formation Stage 2 –30 to 70 hrs‐ Epithelial regeneration Stage 3 –5 to 12 days ‐ Subepidermal granulation Stage 4 –after 12 days – Regression

81. METHODS OF BITE MARKS ANALYSIS:   Odontometric triangle method: • A triangle is made on the tracing of bite marks and teeth models by marking three points, two on the outer most convex point of canines and one in the centre of the upper central incisors. • Three angles measured and compared

82.   Metric analysis Vernier Calipers Computer digitization method

83. Pattern Association Bite mark from victim Models from suspect Comparison -Direct method- suspects model are placed directly over the bite mark photograph -Indirect method- incisal and occlusal edge of the suspect’s teeth may be traced on to clear acetate and superimposed on life-size bite mark photographs.

84. CONCLUSIONS OF BITE MARK ANALYSIS   By Levie Positive identification : characteristic matches between the bite mark pattern and the pattern of the suspect's teeth. Possible identification: • This implies that although the suspect's teeth could have made the bite mark, there are no characteristic matches to be absolutely certain. Excludes identification: • When features on the bitemark indicate that the suspect's teeth could definitely not have caused them, it represents a Negative or exclusion.

85. Cheiloscopy Cheiloscopy is a forensic investigation technique that deals with identification of humans based on lips traces. Lip prints have to be obtained within 24 hours of time of death to prevent erroneous data that would result from post mortem alterations of lip. Pattern depends on whether mouth is opened or closed. Closed mouth position - well defined grooves Open position - ill defined and difficult to interpret

86. Classification of Lip prints By Santos in 1967 Simple wrinkles • Straight line • Curved line • Angled line • Sine-shaped curve Compound wrinkles • Bifurcated • Trifurcated • Anomalous

87.   Suzuki and Tsuchihashi (1970) • 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 cannot be morphologically differentiated.

88.   • A combination of these grooves may be found on any given set of lips. • To simplify recording, the lips are divided into quadrants similar to the dentition - a horizontal line dividing the upper and lower lip and a vertical line dividing right and left sides. • By noting the type groove in each quadrant, the individual's lip print pattern may be recorded.

89. • Lip prints are usually left at crime scenes and can provide a direct link to the suspect • Traditionally, the use of lipsticks was essential to leave behind color traces of lip prints. • In recent years, however, lipsticks have been developed that do not leave any visible trace after contact with surfaces such as glass, clothing, or cigarette butts. Software used for lip print analysis : IBM SPSS software ADOBE PHOTOSHOP software

90. Disadvantage of Lip Print Investigation: • Major trauma to the lips can result in scarring. • Surgical treatment rendered to correct any abnormality also affects the size and shape of the lips, thereby altering the pattern and morphology of the grooves. • The prints produced may differ in appearance depending on the pressure applied and its direction.

91. Questions Short essay questions Role of dentist as forensic expert Lip prints Rugoscopy Bite marks Age estimation methods Gender estimation methods

92. THANK YOU!!