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Odontology

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Forensic Medicine

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Odontology

  1. 1. FORENSIC ODONTOLOGY
  2. 2. Forensic odontology • Forensic odontology is a branch of forensic medicine, and in the interest of justice deals with the proper examination, handling and presentation of dental evidence in the court of law.
  3. 3. Features which can be established by dental examination; 1. Age 2. Sex 3. Race 4. Blood group ( from saliva) 5. Economic Status ( sometimes) 6. Occupation 7. Use of specific medicines 8. General facial characteristics
  4. 4. Stage of tooth development has two periods. 1. Pre-natal period 2. Post-natal period.
  5. 5. Pre-natal period • Calcification of tooth starts in incisors at the tips of milky teeth at 5th month of intrauterine phase. • At time of birth calcification occur; Incisors = 2/3 Canines = 1/3 molars = tip.
  6. 6. 1. Age 1. Eruption of temporary and permanent teeth. 2. Gustafson’s criteria.
  7. 7. Two sets of teeth 1. Temporary, deciduous or milk teeth. 2. Permanent teeth.
  8. 8. Temporary teeth • These are 20 in numbers including ( in each jaw) : Incisors = 4 Canines = 2 molars = 4
  9. 9. Permanent teeth • 32 in number, including (16 in each jaw): Incisors = 4 Canines = 2 Premolars = 4 Molar = 6
  10. 10. Temporary teeth Permanent teeth 1. Small, narrow & light Big, broad & heavy 2. China white in color Ivory white in color 3. Neck is more constricted Neck is less constricted 4. Edges serrated Edges not serrated 5. Anterior teeth vertical Anterior teeth inclined somewhat forward 6. Molars are usually larger Premolars which replace the temporary molars are smaller.
  11. 11. Age of eruption of temporary teeth TOOTH AGE Lower central incisor 6-8 month Upper central incisor 7-9 month Upper lateral incisor 9 month Lower lateral incisor 10 month First molars 12th month Canines 18 month Second molars 2 years
  12. 12. Temporary teeth • Temporary dentition start at = 6 month • completed = 2.5 years • in 1 year total teeth = 8-12 • 1.5 year total teeth = 16 • Calcification of roots completed by the end of third year.
  13. 13. Permanent teeth eruption TEETH Years of eruption First molars 6 Central incisors 7 Lateral incisors 8 First premolar 9 Second premolar 10 Canines 11 second molars 11-12 Third molars 17-18 ( variable)
  14. 14. Permanent teeth • If the 4 wisdom teeth are present, then the age is > 17 years • MIX dentition period is = 6 – 12 years. • Calcification of roots is completed within 3-4 years of eruption.
  15. 15. Gustafson`s method • This method is used for age estimation in adults by studying the progressive changes in an individual tooth.
  16. 16. Gustafson`s criteria 1. Degree of Attrition (wearing off teeth ) 2. Periodontosis ( loosing of teeth ) 3. Secondary dentine formation 4. Cementum deposition. 5. Root resorption 6. Root trasperency.
  17. 17. • MILES ( 1963) suggested that transparency of root is most reliable criteria. • BOYD ( 1963 ) devised a age estimation from incremental lines of enamel. • These lines can be seen on histological section of teeth and represent daily increments of growth. • A well marked line known as NEONATAL LINE, is formed at birth.
  18. 18. DIFFERENCES IN MALE AND FEMALE DENTITION FINDINGS MALE FEMALE Size of upper central & lateral incisors Different Same Size & shape of teeth Mandibular teeth are less pointed & bigger mandibular teeth are more pointed and smaller Mandibular 1st molar Has a fifth cusp Fifth cusp is absent
  19. 19. Race of person • Characterestics of Mongoloids teeth: 1. Shovel shaped upper incisors. 2. Enamel pearls: are small nodules of enamel on the surface. 3.Taurodontism ( bull tooth): the pulp cavity of molars is wide and deep and the roots are fused and bent. 4. Congenital lack of third upper molars is common.
  20. 20. • Carbelli’s cusp: Small nodules on lingual surfaces of maxillary molar is common in WHITE RACES. • Large teeth with more cusps in molars are common in NEGROID.
  21. 21. Common identifying features of teeth • 1. Faulty development; Teeth may be undersized (small), oversized, notched, or present some other irregularities as a result of faulty development and malformation. • 2. Faulty alignment; the defect in the alignment may be 1. In the space b/w the teeth eg. Widely spaced teeth, overriding teeth. 2. b/w the teeth of upper and lower jaw.
  22. 22. Stains; • * Pan (betel leaf, tobacco) chewing habit stains the teeth with dark brown or black deposit. • * Yellowish or dark brown stains on the back of incisor teeth are common in cigarette smokers. • * Chalky white or yellowish brown areas of discoloration on enamel, are found in FLOROSIS. • * COPPER causes green, and MERCURY and LEAD causes blue-black line on the gums. • * PHENYTOIN induces hyperplasia of gums. May indicates and suggests epileptic seizures as a cause of death.
  23. 23. • Localised attrition: Pipe smokers may have localized wear off teeth, either on incisors or at the angles of the mouth due to position of pipe. Notched incisors from holding thread and pins b/w teeth suggest that person was tailor or hair-dresser or a cobbler.
  24. 24. • Medico-legal aspects of dental study • Identification of the individual • Cause of death. The teeth resists putrefaction and the amount of deposition of heavy metals can be detected for a considerable period after death that is especially helpful in poisoning cases • In chronic phosphorus poisoning; evidence of phossy jaw is characteristic. • Bite marks suggest sexual assault. • Artificial dentures; when dislodged can sometimes cause choking in the elderly. • Pink teeth; in putrefied bodies near gum line, teeth are of pink color, it is due to dentine being stained by heamoglobin products.
  25. 25. • Charting of teeth: • Any extractions, recent or old from the condition of the socket. • Any fillings, number and position. • Artificial teeth, whether of gold. Porcelain or stainless stain. • Prosthetic work.
  26. 26. • Any crowned teeth. • Any broken teeth • Pathological conditions in teeth, jaws and gums. • Congenital defects, such as enamel pearls, carbelli`s cusps or ectopic teeth. • Malpositioned teeth, rotated or tilted • General state of care and hygiene like caries. Plaque. Tobacco staining, gingivitis ets.

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