INTRODUCTION TO FORENSIC ODONTOLOGY PART II

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.

1. FORENSIC ODONTOLOGY-PART-II 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 -ETHINICITY -GENDER DETERMINATION

3. CONTENTS-PART-2 --DENTAL PROFILING- ETHNIC ORGIN GENDER DIFFERENTIATION DENTAL AGE ESTIMATION --CRIME INVESTIGATION- BITE MARKS

4. DENTAL AGE ESTIMATION Various methods utilized to determine age from dentition: Clinical or visual method : visual observation of the stage of eruption of the teeth and evidence of changes due to function Radiographic method : provides gross stage of dental development

5. Histological method : - requires preparation of tissues for detailed microscopic examination. - Determines the stage of development more accurately. Physical and chemical analyses : determines the alteration in ion levels with age - Not of great value yet, but in future may be an adjunctive means of collecting evidence.

6. FACTORS USED FOR AGE DETERMINATION USING DENTITION ( Acc to Pretty, 2003) Appearance of tooth germs Earliest detectable trace of mineralization Degree of completion of unerrupted tooth Rate of formation of enamel and neonatal line Clinical eruption Degree of completion of roots of erupted tooth Degree of resorption of deciduous teeth Attrition of crown

7. Formation of physiologic secondary dentin Formation of cementum Transparency of root dentin Gingival recession Root surface resorption Discoloration of teeth Changes in the chemical composition of teeth

8. DENTAL AGE ESTIMATION Final step in dental profiling Post-mortem identification and in living individuals in whom chronological age is under dispute. Different physiological systems like dentition and skeletal system mature at different rate in people with same chronological age PHYSIOLOGICAL AGE: -Determined by –ANTHROPOMETRY -SECONDARY SEXUAL CHARACTERS -DENTITION

9. Different physiologic systems used to estimate age, teeth are considered better suited than bones. Dental age is uniformly applicable from infancy to late adolescence. Teeth continue to undergo changes, making age estimation possible among adults.

10. AGE ESTIMATION METHODS Age estimation using the dentition may be grouped into 3 phases: Ageing in pre-natal, neonatal and early post-natal Age estimation in children and adolescents Age estimation in adults

11. AGE ESTIMATION IN PRE-NATAL,NEONATAL,EARLY POST-NATALPERIOD Neonatal line –used as an indicator of birth. Acc to Bowers, it is where enamel prism growth rate is slowed, creating an apparent line of demarcation. Acc to Ciapparelli , it may take upto 3 weeks after birth to form. If neonatal line present-indicates a live birth

12. Age estimation of skeletal remains- measurement of dry weight of mineralized tooth cusps- developed by Stack. Developing teeth in a child at 6 months I.U weigh abt 60mg 0.5g in a new born 1.8g at 6 months post-natal

13. LEGAL APPLICATIONS In case of foeticide and infanticide . Cases where, unborn is aborted without mother’s consent: Punishment: -- 2 years imprisonment if foetus < 6 months -- 3 years imprisonment if foetus > 6 months

14. AGE ESTIMATION IN CHILDREN AND ADOLESCENTS Two events used- -Tooth emergence -Tooth calcification TOOTH EMERGENCE -convenient clinical method -age estimation of deciduos teeth given by Nystrom -involves visual assesment of teeth in the mouth -requires little expertize and equipment. -under genetic control -relatively regular -commencing at 6 months,completing by 2.5 years.

15. TOOTH CALCIFICATION -Emergence of permanent teeth are under influence of intraoral environment-infections, arch space etc -So it is used in permanent tooth -Radiographs used to assess tooth calcification -Can be assesed for a period of several years -Not altered by local factors -study of tooth calcification also helps assess age at periods when no emergence takes place(2.5-6 years and >12 years)

16. Considered one of the three most suitable methods of estimating age by Schmeling . Technique is simple and easy to master. Accurate as a number of teeth passing through various stages of calcification are available. Better indicator of age in first two decades of life.

17. SCHOURS and MASSLER METHOD Includes 20 chronological stages of tooth development from 4 months I.U until 21 yrs of age. Charts based on histological sections and permit direct comparison with radiographs. The stages shown include the amount of age variation for each stage. This chart was later improved by UBELEKAR .

18. Dental development chart by Schour and Massler showing deciduous dentition mixed and permanent dentition Dental Age Estimation Using Schour and Massler Method in South IndianChildren . Eshitha Ebrahim , Prasanna Kumar Rao, Laxmikanth Chatra . Sch . J. App. Med. Sci., 2014; 2(5C):1669-1674

19. DEMIRJIAN’S TECHNIQUE Uses a Scoring System. It Assess Mandibular Left Side Teeth. Method makes use of 8 developmental stages(A to H). 3 rd molars are not used. Each of 7 teeth is assigned a “maturity score” for each of the developmental stages. The maturity score assigned for each tooth is added and a total maturity score is obtained. This total maturity score is then plotted on a chronologic “age conversion table”.

20. These scores are added to obtain a total maturity score. This total score is usually between 0–100 . The total maturity score (S) is then substituted in the formula to derive the age.

21. Existing Formula for Age Estimation (based on tooth development of French children reported by Chaillet and Demirjian , 2004): 1. For males, Age = (0.000055 x S3) – (0.0095 x S2) + (0.6479 x S ) – 8.4583 [Confidence Intervals: 95% = ± 1.73 years; 99% = ± 2.28 years] 2. For females, Age = (0.0000615 x S3) – (0.0106 x S2) + (0.6997 x S) – 9.3178 [Confidence Intervals: 95% = ± 2.01 years; 99% = ± 2.65 years]

22. Indian Formulas for Age Estimation (developed on a sample of 165 males and 296 females aged 7 to 25 years): 1. For males, Age = 27.4351 – (0.0097 x S2) + (0.000089 x S3) 2. For females, Age = 23.7288 – (0.0088 x S2) + (0.000085 x S3) Age Estimation in Indians Using Demirjian’s 8-teeth Method. Ashith B. Acharya. J Forensic Sci , January 2011, Vol. 56, No. 1

23. LEGAL APPLICATIONS Useful in children upto age of 16 years. May be possible to determine whether a person has attained the age of 16 or not. Law- person between 12-16 yrs commits a crime,gets only half punishment an adult would normally get. A person < 16 years is allowed to work only 6 hours per day 16 years is also the age of consent for attaining majority,eligibility for citizenship,passport and driving licence .

24. AGE ESTIMATION IN ADULTS Gustafson’s method- 1950-Gosta Gustafson proposed the technique. Based on Regressive changes in teeth. it includes: Attrition(A) Secondary dentine deposition (S) Loss of pdl attachment(P) Cementum deposition at root apex(C) Root resorption (R) Dentin translucency (T)

25. For each regressive changes , diff scores ranging from 0-3 were assigned . ( eg - A0 , A1, A2, A3 ) And similar four grades for the other variables. Total score X=A+S+P+C+R+T Eg: X= A3+S2+P2+C1+R2+T1 AGE=11.43+(4.56X) Pillai and Bhaskar estimated in indian population –merely 50% result

26. Maples & Rice correction: --- AGE = 13.45 + 4.56X Johanson’s improvements: --- proposed 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)

27. DENTINE TRANSLUCENCY Bang and Ramm used root dentine translucency alone to estimate age. Root dentin starts to become translucent during the 3rd decade of life beginning at the apex and advancing coronally with age. Alteration is due to decreased diameter of dentinal tubules due to calcification. Diff in Refractive Index b/w intratubular organic & extratubular inorganic matter is equalized resulting in increased translucency of affected dentin.

28. The changes in the dentinal translucency could also be due to changes in the organic substance of the dentine,possibly fatty degeneration. For age estimation, translucency length( in mm) or area(mm square) may be measured on intact or sectioned teeth.

29. AGE= B0+ B1X+ B2X2(Zones of translucency<=9 mm) AGE= B0+ B1X(Zones>9 mm ) B0-regression constant B1, B2-regression coefficients X –translucency length DISADVANTAGES: - irregular junction of translucent and non transculent zones, difficulty in measuring length. -under estimation of age in older age groups.

30. BIOCHEMICAL INDICATORS OF AGE AMINOACID RACEMIZATION- Relatively new method HELFMAN AND BADA –suggested relationship b/w age and extent of amino-acid racemization in dentin Aspartic acid-rapid rate of racemization i.e. Conversion from one type to another. L-aspartic acid to D-aspartic acid with increasing age. D-L ratio used for age estimation-constant change in ratio at different ages. Racemization rate of aspartic acid- high in enamel and root dentin

31. AGE ESTIMATION FROM INCREMENTAL LINES OF CEMENTUM KAGERER AND GRUDE-age estimation from acellular cementum incremental lines Age estimation accuracy within 2-3yrs of actual chronological age REN and RADLANSKI- some teeth differ markedly in the number of incremental lines in different sections as well as in different regions of same section Requires tooth extraction in living individuals NON-DESTRUCTIVE radiographic method by KVAAL was used as alternative

32. RADIOGRAPHIC METHOD OF KVAAL Pulp size measurement of 6 Teeth were observed Max CI, LI, II PM, Mand CI, LI, Canine in IOPA Measurements- ( P)- pulp-root length (R)-pulp-tooth length (T)-tooth-root length

33. ( A)-pulp-root width at CEJ (C)- pulp-root width at mid-root level (B)- pulp-root width at mid point level between A and C Mean value of all ratio excluding T (M), Mean value of B and C (W) Mean value of length ratio P and R (L) AGE=129.8-(3.164×M)-(66.8×(W-L))

34. BITE MARKS Mac Donald defines it as “a mark caused by teeth either alone or in combination with other mouth parts”. Humans /animals-on tissue /objects. Results when Teeth employed -as weapon in act of dominance . Asso with sex crimes,violent fight,child abuse,theft .

35. Matching of bite mark to suspect’s dentition is done for law enforcement. Sweet and Pretty considered size, shape and pattern of incisal or biting edges of U/L anterior teeth-unique and specific to individual. A forensic dentist is usually consulted when bite marks are visible

36. CLASSIFICATION Cameron and Sims: 1. Agents a. Humans b. Animals c. Mechanical 2. Materials a. Skin and body tissues b. Food substances c . Other materials chewed habitually

37. Mc Donald’s classification Tooth pressure marks Tongue pressure marks Tooth scrape marks Complex marks Webster’s Classification Type I ‐Limited depth of tooth penetration. eg -hard chocolate Type II – Considerable depth of tooth penetration. eg -apple Type III – Complete or near complete penetration. eg -cheese

38. TYPES OF BITE MARK INJURY Indentations Contusions or Bruises Lacerations Avulsions

39. Contusions or Bruises: Reddish / purplish discoloration of skin surface due to blood escape in to subcutaneous tissue Lacerations : Break in integrity of skin surface due to the bite Indentations: Compression of the skin surface due to tooth pressure during a bite

40. IDENTIFICATION OF BITE MARK Gross features Class features Individual features Represents teeth with fractures or rotations Pattern present in the bite mark Circular / Elliptical mark

41. HISTOPATHOLOGICAL STAGES Stage 1 – 0 to 18 hrs –Scab formation Stage 2 – 30 to 70 hrs -Epithelial regeneration Stage 3 – 5 to 12 days ‐ Subepidermal granulation tissue formation Stage 4 – after 12 days –Regression

42. HISTOPATHOLOGICAL CHANGES IN BITE MARKS

43. BITE MARK APPEARANCE TYPE OF INJURY-compression of skin surface due tooth pressure bite causes indentations Indentations disappear due to elastic nature of skin Edema and subcutaneous bleeding-CONTUSIONS OR BRUISES-purple /red in colour When intensity great –LACERATIONS AVULSION-when part of tissue is bitten off

44. IDENTIFYING THE BITE MARK Acc to SWEET,it is identified by following features 1.GROSS-circular/elliptical with central ecchymosis 2.CLASS FEATURES- Incisors-rectangular Canine-triangle/rectangular PM and molars-spherical/point shaped 3.INDIVIDUAL FEATURES- Rotations,spacing,fractures

45. BITE MARK EVIDENCE COLLECTION Should be collected when 1 st observed. If criminal in nature report to law enforcement. Primary concern should be patient care-to prevent infection Protocol followed for bite mark collection that follows AMERICAN BOARD OF FORENSIC ODONTOLOGY (ABFO)

46. PROCEDURE

47. 1. CASE DEMOGRAPHS NAME,AGE,SEX OF VICTIM 2. VISUAL EXAMINATION Orientation and location Type of injury Colour,size,shape Contour,texture,elasticity Difference b/w u/l arches and between individual teeth 3. PHOTOGRAPHY permanent record orientation and close up photographs

48. Orientation photograph-photographs that depict the location of bite mark on the body Close up photograph-made with rigid referance scale such as ABFO No.2 scale that is placed on same plane as bite mark 2nd photograph taken without scale-so no part of mark has been masked by scale.

49. 4. SALIVA SWAB- Saliva deposited have DNA,WBCs,sloughed epithelial cells -Use cotton swab moistened with distilled water. –Applications: Salivary DNA ANALYSIS 5. IMPRESSIONS-uses vinyl polysiloxane , reinforced with dental stone Pre-moistened swab

50. EVIDENCE COLLECTION FROM SUSPECT Obtained after court order Includes- Photograph of suspects teeth in occlusion and in open bite B) Maxillary and mandibular impressions C) Saliva swab

51. BITE MARK ANALYSIS AND COMPARISON Recognize uncommon characters- frature , diastema,rotation,loss of particular teeth. Measurement of mark done by METRIC ANALYSIS-using vernier caliper /computer software-compare Match the configuration of bite injury to arrangement of teeth on suspect’s dentition-”PATTERN ASSOCIATION”.

52. Metric Analysis – odontometric triangle method Test bites Other methods 1. Trans illumination of tissue 2. Scanning electron microscopy 3. video superimposition 4. stereomicroscopy

53. Direct method : by CIAPPARRELLI Suspects model is placed directly over the bite mark photograph or on bite mark itself. Indirect method - incisal and occlusal edges of suspects teeth traced onto clear acetate paper and super imposed on life size bitemark photographs JOHANSEN AND BOWERS-use of Adobe photoshop

54. Odontometric triangle method Triangle are made on bite marks and teeth models by marking three points Two reference points on outer most convex point of canines and one in the center of centrals Three angles measured and compared

55. Other metric analysis: Length and width of teeth Overall size of mark Inter-canine distance Spacing between two marks Rotation from normal arch form

56. Pattern Association Models from suspect Bite mark photograph from victim Comparison

57. CONCLUSION Positive Identification - indicates that there are characteristic matches between the bite mark pattern and the pattern of 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 bite mark indicate that the suspect’s teeth could definitely not have caused them,it represents a negative or exclusion.

58. 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 2: Teeth as weapons of violence —identification of bitemark perpetrators. D. Sweet and I. A. Pretty . British Dental Journal, volume 190, no. 8, april 28, 2001 . Age Estimation in Indians Using Demirjian’s 8-teeth Method. Ashith B. Acharya. J Forensic Sci , January 2011, Vol. 56, No. 1. Dental Age Estimation Using Schour and Massler Method in South IndianChildren . Eshitha Ebrahim , Prasanna Kumar Rao, Laxmikanth Chatra.Sch . J. App. Med. Sci., 2014; 2(5C):1669-1674