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Medico-legal Investigation. Skeletalization &Forensic Odontology. Skeletalization. The environment is more important than the time in this process. 12-18 months: bone and tendon tags After 3 yrs : bare bone .
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Medico-legal Investigation Skeletalization &Forensic Odontology
Theenvironment is more important than the time in this process. • 12-18 months:bone and tendon tags • After 3 yrs: bare bone. • In temperate zones the bones will remain solid & heavy with the preservation of bone marrow in long bones for a number of years. • After 40-50 years : • Surface of the bone becomes dry & brittle • Marrow cavity will be empty.
The individual was recovered in a home with rats. Post-mortem bite marks are yellow, bloodless defects with scalloped edges.
Post-mortem vulture activity on a woman discovered in a wooded area. The tendon is visible through the hole while much of the muscle is absent. The yellow discoloration around the hole is consistent with beak marks
The skeleton is that of an adult male who was missing 1.5 months during late fall in the southeastern US. He was found in a wooded area. Gnaw marks are evident on several ribs.
Forensic Odontology is the application of dentistry in legal proceedings deriving from ANY evidence that pertains to teeth. Forensic Odontology
Hardest part of body attached to jaws. Teeth serves to help digest food, act as a defense mechanism, etc. Teeth
Teeth Basics • Tooth consists of • Root • Root canal • Dentin • Enamel Types of teeth. Left to right: Incisor, Canine, Premolar, molar.
Forensic Odontology • Human Dentition and Dental Anatomy • Enamel is the hardest substance in the human body • Full compliment of adult dentition of 32 teeth • Each tooth presents 5 surfaces in a visual examination for a total of 160 surfaces • Arranged in 2 Dental Sets called “arches” • One Upper Arch = Maxillary Jaw • One Lower Arch = Mandibular Jaw
Forensic Odontology • Human Dentition and Dental Anatomy • Dental Arches are Symmetrical • Each Quadrant contains the same “number and type” of teeth
Adulthood Teeth through the years Childhood Primary teeth sprout from milk buds and are temporary. Once they fall out, permanent teeth as seen on the other side appear. Permanent adult teeth come in when primary teeth fall out; they are permanent because they establish roots inside the gums. Third molars come in around the mid teenage years.
Forensic Odontology • The Human has the following: • 2 Incisors = sharp, flat, wide teeth for cutting • Cuspid = tearing, ripping and gripping • 2 Premolar = 2 cusps for biting and crushing • 3 Molar = 3-5 cusps (wide biting area) • Third molar = Wisdom (last tooth in arch)
Forensic Odontology • Key to Dental Anatomy is: • Orientation • Tooth Surface • Landmarks and Structures • M = mesial • O = occlusal • D = distal • L = lingual • B = buccal distal ←, mesial →, coronal ↑, apical ↓.
Individual Characteristics • Size of tooth • Shape of tooth • Shape of root • Placement of tooth • Quantity of teeth • Combinations of dental work done: • Crowns • Extractions • Bridge • Fillings • Root canals Various dental work
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
Why Teeth? • Every human body ages in a similar manner, the teeth also follow a semi-standardized pattern. These quantitative measurements help establish relative age of person. • Each human has an individual set of teethwhich can be traced back to established dental records to find missing individuals. • Teeth are made of enamel (hardest tissue of the body) so they 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 to help identify a person.
Forensic Odontology • Scope of FO is the following: • Identification of unknown decedents by analyzing dentition (teeth), jaw structure, craniofacial bones, maxillofacial bones • Bite mark investigation • Examination of oral-facial trauma involving person/child abuse • Medico-legal jurisprudence and expert witness testimony
Who practices Forensic Odontology and what do they do? • Forensic Odontologists • Must have DDS degree • Should have specialized training in the field through lectures (not required) • Forensic dentists 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 Top: Forensic Odontologist analyzing animal teeth for comparison. Side: Seal for American Board of Forensic Odontology.
History • The earliest known identification from teeth is in 1775 by Paul Revere. • Paul Revere made a silver bridge for one man. The man was killed in the Revolutionary War. • Body was in a mass grave and identified by his silver dental work and hippo tusk.
History of Forensic Odontology • 66AD – First body identified using teeth • Lollia Paulina • 1849 – Mass deaths at Vienna Opera House Fire • Dental evidence is first admitted into court system in US
Organizations of Forensic Odontology Bureau of Legal Dentistry (BOLD) American Board of Forensic Odontology (ABFO) International Organization for Forensic Odonto-Stomatology (IOFOS)
Forensic Odontology • Postmortem dental examination should include examination of: • Missing, unerupted or extracted teeth • Restorations and prosthesis • Decay and broken teeth • Malposition, overlapping, crowding and spacing
Identifying factors such as cavities, tooth pattern, and general dental health neglect
Forensic Odontology • Peculiar shapes of teeth • Root canal on x-ray • Bone pattern on x-ray • Bite patterns
Impressions from teeth found on skin or items left at a scene. Usually outline teeth placement. Bite Marks
Forensic Odontology • Forensic Odontology may include the study of bite mark patterns on the victim. • Digital overlay is used to make a comparison.
List of Skull Bones for You to Know • Frontal • Parietal • Occipital • Temporal • Zygomatic (and arch) • Orbit • Maxilla • Mandible