ODONTOLOGY Forensic Dentistry

Definition of Odontology “The application of the arts & sciences of dentistry to the legal system.” –Identification of individuals –Bite mark analysis –Analysis of personal injury to head/neck –Dental malpractice

Dentition Descriptions Primary Dentition –“Baby” teeth; 20 total –Develop in utero around 16 weeks –Eruptions begins around 6 months Secondary Dentition –“Permanent” Teeth –32 teeth total

Teeth Type Incisors 8 total; used to cut food Cuspids 4 total; used to tear food. “Eye teeth” or “Canines” Bicuspids 8 total; used to crush food. “Pre-molars”; primary larger than secondary. Molars 12 total; used to grind food. No primary molars.

DNA

Primary Dentition Labeling From the midline to the posterior the teeth are: –Central Incisor –Lateral Incisor –Cuspid –Bicuspid (premolar 1) –Biscuspid (premolar 2)

Primary Dentition Labeling Looking at the child, starting at the top right working clockwise, the teeth are labeled A - T.

Secondary Dentition Labeling From the midline to the posterior the teeth are: –Central Incisor –Lateral Incisor –Cuspid –Bicuspid (premolar 1) –Bicuspid (premolar 2) –Molar (6 year old) –Molar (12 year old) –Molar (wisdom tooth)

Secondary Dentition Labeling Looking at the adult, starting at the top right and working clockwise, the teeth are labeled # 1-32.

Secondary Dentition 1. 3rd Molar (wisdom tooth) 2. 2nd Molar (12-yr molar) 3. 1st Molar (6-yr molar) 4. 2nd Bicuspid 5. 1st Bicuspid 6. Cuspid (canine/eye tooth) 7. Lateral incisor 8. Central incisor 9. Central incisor 10. Lateral incisor 11. Cuspid (canine/eye tooth) 12. 1st Bicuspid 13. 2nd Bicuspid 14. 1st Molar (6-yr molar) 15. 2nd Molar (12-yr molar) 16. 3rd Molar (wisdom tooth) 17. 3rd Molar (wisdom tooth) 18. 2nd Molar (12-yr molar) 19. 1st Molar (6-yr molar) 20. 2nd Bicuspid 21. 1st Bicuspid 22. Cuspid (canine/eye tooth) 23. Lateral incisor 24. Central incisor 25. Central incisor 26. Lateral incisor 27. Cuspid (canine/eye tooth) 28. 1st Bicuspid 29. 2nd Bicuspid 30. 1st Molar (6-yr molar) 31. 2nd Molar (12-yr molar) 32. 3rd Molar (wisdom tooth) Source: American Dental Association "Current Dental Terminology Third Edition (CDT-3)" (c) 1999.

Primary Eruption Guidelines

Secondary Eruption Guidelines

Mixed Dentition - Skulls

2 year old

5 year old

X-rays of Mixed Dentition

Newborn Boy 6 month old Girl

1 year old Girl 9 month old Girl

2 year old Girl 3 year old Girl

4 year old Boy5 year old Boy

6 year old Boy7 year old Boy

9 year old Boy 10 year old Boy

Postmortem Examination FOR IDENTIFICATION –If the body can be viewed at a funeral, the forensic dentist examines in the mouth. Rigor mortis must be broken. –Myotomy (cutting of facial muscles) –Jaws are removed if the body is not fit for viewing. 30% H 2 O 2 for 24 hours to remove any remaining soft tissue.

Postmortem Examination State presence or absence of each tooth –If missing, socket or healed? (Socket implies tooth was recently lost). –If present, erupted or unerupted? Filled? What materials? –Gum disease? General anatomy? X-rays to compare to antemortem records.

Antemortem Examination Found at dental offices, military, prisons & hospitals. Need preliminary identification to search for antemortem records. –Driver’s license, photo ID, etc…

Website for practice! re_Folder/case1.htmhttp:// re_Folder/case1.htm

Mass Disasters Team 1 –removal of jaws/teeth from the scene. Team 2 –postmortem exams at the morgue. –Shift <3 hours, max every other day. Team 3 –Antemortem exams & record collection. Team 4 –Data posting into exams; both post & antemortem. Chief Forensic Dentist –Makes the actual identification.

Profiling Using the characteristics of the teeth to reduce the population from which one searches for the unidentified decedent.

Profiling 1 Dental erosion on the inside (tongue side) of the teeth. Caused by excessive vomiting: –Bulimia –Alcoholism –Gastric problems

Profiling 2 Severe staining –Top & bottom teeth Caused by antibiotic tetracycline. –Taken while teeth were developing.

Profiling 3 Abnormal tooth wear from pipe smoking.

Profiling 4 Occupational Hazard…..? –Electrician –Uses teeth to strip plastic coating from wires.

Profiling 5 Country of residence –Performed in Russia. –Evidence of dentistry in the former Soviet Union.

Profiling 6 Personal Habits –Smoker –Poor personal oral hygiene habits.

Bitemark Analysis Used to identify victims & assailants. Most common in cases of rape, murder, child abuse, & spousal abuse. –Attacker – bites on hands, shoulders –Victim – bites on breasts & buttocks. More useful on dead victims because of the lack of inflammatory response.

Bitemark Patterns Two (2) horseshoe patterns Shape depends upon surface bitten, biting force, & victim resistance. –Muscle = distinct pattern –Fat = less distinct pattern –Defensive bite = less distinct, more bruising, tearing. –Offensive bite = distinct bite

Bitemark Severity & Significance Scale 1) Very mild bruising, no individual tooth marks present Diffuse arches visible; may be caused by something other than teeth Low forensic significance

Bitemark Severity & Significance Scale 2) Obvious bruising with individual, discrete areas associated with teeth. Skin remains intact. Moderate forensic significance

Bitemark Severity & Significance Scale 3. Very obvious bruising with small lacerations. Likely to be assessed as definite bitemark. High forensic significance

Bitemark Severity & Significance Scale 4) Numerous areas of laceration, with some bruising, some areas of the wound may be incised. Unlikely to be confused with any other injury mechanism. High forensic significance.

Bitemark Severity & Significance Scale 5) Partial avulsion of tissue, some lacerations present indicating teeth as the probable cause of the injury. Moderate forensic significance.

Bitemark Severity & Significance Scale 6) Complete avulsion of tissue, possibly some scalloping of the injury margins suggested that teeth may have been responsible for the injury. May not be an obvious bite injury. Low forensic significance

Ted Bundy Conviction - Victim

Ted Bundy Case