Forensic Odontology Teeth and Bite Mark Evidence What

Forensic Odontology Teeth and Bite Mark Evidence

What is a Forensic Odontologist? Most forensic odontologists are practicing dentists. However, they have gone through specialized training to understand how to apply forensic science to dentistry. Most are members of a professional organization.

The Importance of Forensic Odontology A forensic investigation of teeth will help to determine: • -Individual Identification • -Mass Disaster Identification • -Bite mark analysis • -Dental Malpractice

An Understanding of Teeth • Teeth begin to appear at 6 months of age and all should have emerged by age 3. • Humans have 20 deciduous (baby) teeth. • Between the ages of 7 -21 years all of the deciduous teeth should have been replaced with permanent teeth. • Adults have 32 permanent teeth. This includes the four wisdom teeth. • Teeth are the hardest substance in the body.

Age Chart for Deciduous and Permanent teeth

Teeth Numbering System • Teeth are numbered from 1 to 32 starting from the upper right (1), to upper left (16), down to lower left (17) to lower right (32).

The 4 types of the Teeth • • • The 4 types of teeth: Incisors Canines Premolars Molars

The 5 Surfaces of the Teeth • Each tooth has 5 surfaces: – M – mesial (front) – D - distal (backside) – O - occlusal (biting surface) – F – facial (cheek side) – L - lingual (tongue side)

Tooth Composition

Identification using Teeth Many times identity of a skeleton can be determined by comparing the teeth features in the skull to dental records. Unusual features including the number and types of teeth and fillings, the spacing of the teeth, and/or special dental work (bridges, false teeth, root canals) help to make a positive identification.

Example of a Dental Record • Today, most people have a dental record. • Dental records have information about the condition of each tooth and this information is compared to the postmortem report.

Dental Work That Makes Teeth Unique Dental Crown Dental Fillings

Dental Work That Makes Teeth Unique (cont) Dental Extraction Dental Bridge

Postmortem Dental Information will include any unique dental features

Lifestyle Effect on Teeth will also help to identify the body • First, the antemortem (before death) and postmortem (after death) X-rays are compared. • Next, the investigator will look for other lifestyle indications from the teeth. For example, smoking.

Example of X-ray comparison.

Example of X-ray Comparison

Lifestyles and Teeth • Mouth of a smoker • Mouth of a Meth user

Dentures • There are cases where the victim no longer had teeth and wore dentures. • Records are also kept for dentures so this dental appliance is a very good source.

Cases of Identification using Teeth • The first case – Roman Emperor Claudius to recognize his beheaded mistress. • First U. S. Court case- in 1849 the incinerated remains of George Parkman were identified using a partial denture. • First case using dental records- identified the victims of the Vienna Opera House fire in 1878.

Cases of Identification using Teeth • In more recent times, teeth identification has been used in mass disasters such as plane crashes, fires and bombings. • Approximately half of the victims from the September 11, 2001 attack on the World Trade Center were identified using DNA, jewelry and dental records.

Bite Mark Evidence • Forensic odontologists will also work on cases that involve bite mark evidence. • Bite marks are found when teeth are used as weapons.

Bite Mark Evidence • Bite mark evidence is controversial because skin is elastic and distortable. • The accuracy of this evidence is often questioned by the court. • Many bite mark cases are overturned. • However, this evidence is very helpful in excluding suspects. • Many times the saliva on the bite mark allows DNA analysis.

Ted Bundy • The Ted Bundy Case is a very famous bite mark case. Bundy had a very unusual bite and was convicted on this evidence.

Ted Bundy and his teeth configuration that caused the unusual bite