1 / 35

Forensic Odontology

Forensic Odontology. Students Will Be Able To:. Distinguish between odontology and forensic odontology. Describe the structure of a typical tooth. Compare and contrast permanent and deciduous human dentition. Odontology.

layne
Télécharger la présentation

Forensic Odontology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Forensic Odontology

  2. Students Will Be Able To: • Distinguish between odontology and forensic odontology. • Describe the structure of a typical tooth. • Compare and contrast permanent and deciduous human dentition.

  3. Odontology • It is the study of the anatomy and growth of teeth and diseases associated with the teeth and gums.

  4. Forensic Odontology • It is the application of dentistry in legal proceedings deriving from ANY evidence that pertains to teeth

  5. The Field • Requirements • Must have DDS degree • Should have specialized training in the field through lectures (not required) • Help • Identify human remains (individual and mass) • Analyze bite marks • Bite marks are compared to known teeth molds to find origin of bite injuries • Estimate age of the victim and perpetrator • Trace dental malpractice

  6. Why Teeth? • Every human body ages in a similar manner, the teeth also follow a semi-standardized pattern • Help establish relative age of person • Each human has an individual set of teeth which can be traced back to established dental records to find missing individuals • Teeth aremade of enamel (hardest tissue of the body) so it can withstand trauma (decomposition, heat degradation, water immersion, and desiccation) better than other tissues in body • Teeth are a source of DNA: dental pulp or a crushed tooth can provide nuclear or mitochondrial DNA that to help identify a person

  7. Physiology of Teeth • Digestion begins in the mouth as enzymes in saliva break down food particles as the teeth grind and crush large pieces of food

  8. Anatomy of Teeth • Typical tooth has three parts • Crown • Is the part of the tooth above the gum line • Neck • Is the place where the crown and the root meet at the gum line • Root • Is embedded in the bony socket of the jawbone

  9. Anatomy of Teeth • Teeth are contained in the alveolar process of the maxilla and mandible • Maxilla= upper jawbone • Mandible= lower jawbone

  10. Anatomy of Teeth • Composed of dentin • Gives the tooth its shape • Can be calcified or hardened • Often covered by enamel on the crown • Is calcium carbonate and calcium phosphate that helps protect the dentin from acid erosion • Covered by cementum in the root of the tooth • Anchors the tooth to the periodontal ligament • Ensures that teeth stay in proper location • Inside of tooth filled with tissue called pulp • Contains nerves and blood vessels

  11. Anatomy of Teeth • Two forms of teeth exist • Deciduous (baby) • Erupt from the gum around 6 months of age • 20 in all • Begin to fall out around age 6 • Adult (permanent) • Replace deciduous teeth • 32 in all

  12. Anatomy of Teeth • Shape and size of each tooth reflects its functions • Molars • Are broad flat teeth in the back of the mouth that are used to crush and grind food • Premolars • Have two pointed surfaces with which to grind and crush • Canine/Cuspids • Have one pointed surface and are used for tearing and shredding food • Incisors • Are the sharp cutting teeth in the front

  13. Students Will Be Able To: • Recognize the value of odontology in forensic investigations. • Explain how teeth and craniofacial features are helpful in estimating age, ancestry, and sex. • Differentiate between the dentition of humans and other animals.

  14. Use of Teeth to Estimate Physical Characteristics • Are more resistant to burning and decomposition than other tissues • Dental fillings, caps, and bridges often remain intact after death

  15. Physical Characteristics of Teeth • Include • Staining • Enamel erosion • Wear on the surface of the teeth • Shape of teeth • Gaps between teeth • Placement of fillings or dental work • Missing teeth • Broken teeth • Tooth alignment • Can be used to develop a biological profile of a decedent based off personal habits that can be used to match a missing person

  16. Age Estimation • Teeth emerge before age 25 in a predictable pattern • Can be used to develop accurate estimates of the age of victims younger than age 25 • After age 25, estimation is more difficult due to teeth being fully emerged • Less accurate estimate involves looking at eating habits, teeth grinding, dental work, and receding gums • Can be off by 4 years

  17. Ancestry Estimation • Certain craniofacial characteristics can be used to estimate a person’s ancestry • Includes • Prognathism • Orthognathism • Chin point • Size and shape of teeth

  18. Ancestry Estimation • Prognathism • Is the forward projection of the alveolar processes that contain the upper and lower teeth • Exhibited by individuals of Australian and African descent

  19. Ancestry Estimation • Orthognathism • Is the absence of the forward projection of the alveolar processes • Exhibited by individuals of European descent

  20. Ancestry Estimation • Chin point • Is projected in individuals of European and Asian descent • Is rounded in Australian aborigines and South Pacific islanders • Often called rocker jaw • Is intermediate in individuals of African descent

  21. Ancestry Estimation • Size and shape of teeth (incisors) • Individuals of Asian descent have shovel-shaped incisors instead of straight incisors

  22. Sex Estimation • Is difficult • Can be based off size and shape of teeth • Males have larger teeth than females • Canines in females are more pointed than in males

  23. Use of Teeth to Determine Identification • Identifications using dental records and photographs showing teeth are important when personal effects are not present on the person or if the remains have become skeletonized

  24. Dental Records • Teeth, skull, and jawbones are sent to forensic odontologist to make a positive identification • Antemortem records taken during life are compared to postmortem records after death • Dental implants and other dental work are useful for identification due to the presence of serial numbers on them

  25. Analyzing Teeth • The Universal System • Teeth are given a specific number • Primary teeth are given specific capital letter • Any dental work done on surface is noted • Sheets kept on dental file forever • When person is missing, files are transferred to the missing person’s office

  26. Bite Marks • Are impressions left on food, skin or other items left at a scene from an individual’s teeth • Porous surfaces that absorb the impact enough to make an impression • Impressions vary • Depending on the pressure applied, the impression will show accordingly • The more pressure there is, the more detail to the bite

  27. Analyzing Bite Marks • Bite marks are photographed with a scale • Bite marks on skin are taken over repeated intervals • Casts of impression are taken • Impression traced onto transparencies • Casts of suspects teeth are taken • Comparison between suspect cast and bite mark

  28. Animal Bite Marks • Nonhuman bite marks have a different dentition pattern than human bite marks • D0gs have 42 teeth while humans have 32 teeth • Shape of the mouth of an animal is more clearly distinguishable from the shape of a human mouth • Dog has a long, narrow arch compared to a C- or U-shaped arch of humans

More Related