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 incisor8. Central incisor9. Central incisor10. Lateral incisor11. 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 Bicuspid22. Cuspid (canine/eye tooth)23. Lateral incisor24. Central incisor25. Central incisor26. Lateral incisor27. 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

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2 year old

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5 year old

X-rays of Mixed Dentition

Newborn Boy6 month old Girl

1 year old Girl9 month old Girl

2 year old Girl3 year old Girl

4 year old Boy 5 year old Boy

6 year old Boy 7 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% H2O2 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!

• www.forensicdentistryonline.org

• http://www.forensicdentistryonline.org/Fire_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