Forensics: Unit 2 - Forensic odontology

The term for anything referring to the mouth, or oral cavity, is known as

buccal

The scientific term for your gums is

gingiva

What are the three names for your baby teeth?

• Primary teeth 

• Deciduous teeth 

• Milk teeth 

Dentition

arrangement of different teeth

Central/lateral Incisor

a broad flat sharp tooth found at the front of the mouth. Designed for biting and cutting food

Canine/cuspid

a sharp pointed tooth for piercing flesh and tearing

Pre-molar/bicuspids & molar (general)

a broad flat tooth with many cupsid. Its rough surface is used for crushing, grinding, and chewing food 

Pre-molars

smaller than molars, bicuspids, 2 points

Molars

4 points/cuspids, come after pre-molars

How many of each tooth does an adult have?

• 32 teeth, if you get wisdom teeth out then 28 

• 16 in the upper jaw, 16 lower jaw

• 2 incisors, a canine, 2 premolars, and three molars on each jaw

The last 4 molars in an adult’s mouth have a special name. What is it?

Wisdom teeth

The protective outer white layer of the tooth is known as the

enamel

• Protection layer, the hardest part

The brown/yellow second layer of the tooth is called the

dentin

An adult has BLANK teeth, while a baby only has BLANK teeth.

32,20

Two names for your adult teeth are your BLANK teeth and BLANK teeth

Secondary, permanent

Secondary teeth that are not yet mature and are located below the gum line are known as BLANK

buds

Around what age do baby teeth ERUPT? Around what age do they SHED?

Erupt: 6 months, shed: 6 years old

According to your lab, around what age should an adult have a full set of secondary teeth?

21-22

What is bruxing?

The tendency to gnash and grind teeth

Bruxing symptoms

• Cracking enamel 

• Shortened tooth which may cause strain on other teeth

• Cause cavities very easily 

• Fillings or crowns 

• Fractured teeth 

What can dental impressions be used for in Forensics?

• Bite marks for identification 

  • Unique per person 

  • Saliva contains DNA and/or ABO antigens 

• Used a lot in missing child cases 

• Postmortem identification

Bite mark

a patterned injury in the skin or other substances produced by teeth

What does a Forensic Odontologist do?

Collect, examine, and preserve evidence and compare it to unique dental characteristics of exemplars. 

exemplar

Impressions taken from a suspect (only known suspects)

List the 4 steps in processing a bitemark

• Photograph 

  • With and without scale

• Swab (for possible DNA)

  • Moistened swabs with sterile water 

  • Air dry 

• Photograph again 

• Cast (if possible)

  • Only done with an impression mark 

When taking pictures of a bitemark, why do you think it’s important to take 90° photographs of the upper and lower jaw of the bitemark?

To get the whole jaw in the picture

What are some reasons as to why obtaining a saliva sample can be more beneficial than obtaining a blood sample?

• Can detect levels of steroids in the body better than blood or urine 

• Easy test collection 

  • Allows CSI unit to control the time better 

  • Noninvasive, simple, safe, stress-free, and painless

• Hormones remain stable in saliva at room temperature for weeks 

• Less expensive than blood testing