Forensic Odontology PDF

FORENSIC ODONTOLO GY Contents Introduction BITE MARK ANALYSIS LIP PRINTS Historical evidences AMELOGLYPHICS Scope and purpose FINGER PRINTS ROLE OF RADIOGRAPHS Personal identifi...

FORENSIC ODONTOLO GY Contents Introduction BITE MARK ANALYSIS LIP PRINTS Historical evidences AMELOGLYPHICS Scope and purpose FINGER PRINTS ROLE OF RADIOGRAPHS Personal identification DENTIST AS AN EXPERT WITNESS Basis of dental identification CONCLUSION Technique of identification Identification in mass disaster Sex differentiation Dental age estimation  INTRODUCTION: Forensic means legal: A word that comes from Latin, meaning “to the forum”. The forum was the basis of Roman law and was a place of public discussion and debate pertinent to the law. FDI defined it as “that branch of forensic medicine which in the interest of justice, deals with the proper handling and examination of dental evidence and also with proper evaluation and presentation of the dental findings”.  Forensic odontology involves the management, examination, evaluation and presentation of dental evidence in criminal or civil proceedings, all in the interest of justice. The subject can be divided roughly into three major fields of activity: Civil or noncriminal, criminal and research  Civil class - malpractice and other aspects of fraud and neglect, in which compensation is sought. Identification of the dead and living also comes under this category. Criminal sector – identification from bite marks that may be present on the victim, or on some inanimate objects such as food items. Research field encompasses academic courses for undergraduate and postgraduate training, teaching Forensic dentistry to police and new research works.  Historical evidences Dr. Oscar Amoedo, Paris, is considered as "Father of Forensic Odontology". Dental evidence played a vital role in historical case of identification of Adolf Hitler. His dental findings were compared with antemortem dental records and radiographs. Dentition was an important lead in the identification of remains of various leaders, who were killed, like Zia Ul Haq, former Pakistani President and Rajiv Gandhi, former Indian Prime Minister.  Mass disaster- World Trade Centre in September 11, 2001. Recently in Nirbaya case suspects are confirmed , By Dr. Ashith Acharya using forensic odontology. Federation Dentair International in 1968 has recommended to include forensic odontology in the curriculum of teaching institutions. First formal instructional programme in forensic dentistry was given in United States at the Armed Forces Institute of Pathology  SCOPE AND PURPOSE : Management and maintenance of dental records that comply with legal requirements Identification of human remains by comparing antemortem and postmortem dental information. Collection and analysis of patterned marks (bite marks) on inanimate material or injured tissue. Recognition of the signs and symptoms of human abuse. Assessment of the age of the person Determination of sex of a person  REASONS FOR IDENTIFICATION OF HUMAN REMAINS Criminal: Typically an investigation to a crime death cannot begin until the victim has been positively identified. Marriage: Individuals from many religious backgrounds cannot remarry unless their partners are confirmed deceased. Monetary: The payment of pension, life insurance and other benefits relies upon positive confirmation of death. Burial: Many religions require that a positive identification be made prior to burial in geographical sites  Social: Society's duty to preserve human rights and dignity beyond life begins with identity. Closure: The identification of individuals missing for prolonged periods can bring sorrowful relief to family members.  Personal identification Identification is the establishment of a person’s individuality Defined as ‘the characteristics by which a person may be recognized’. Methods Traditional methods -visually recognizing body -personal property such as clothing ,jewels etc Burned or decomposed can be very difficult for friends and relatives  tattoo jewels Eye color Analyze physical features: Physical features- inherited and acquired Inherited feature include ethnic characteristics Acquired features- surgical scars, previous fractures, dental restorations. Physical features –prone to change over time Finger prints - undergo postmortem change  Dental hard tissues and Dental materials - resistant to post mortem decomposition Dental evidence is the method of choice in establishing identity of badly burned, decomposed and skeletal remains  BASIS FOR DENTAL IDENTIFICATION: Human Dentition is never same in any two Individuals The morphology and arrangement of teeth vary from person to person Dental identity -″total of all characteristics of the teeth and their associated structures which, while not individually unique, when considered together provide a unique totality” Teeth are relatively resistant to environmental insults after death  TECHNIQUES OF IDENTIFICATION: 1)COMPARATIVE DENTAL IDENTIFICATION: attempts conclusive identification by comparing the dead individuals teeth with presumed dental records of the individual. ORAL AUTOPSY OBTAINING DENTAL RECORDS COMPARING POST AND ANTEMORTEM DENTAL DATA WRITING A REPORT AND DRAWING CONCLUSIONS 2) RECONSTRUCTIVE GROUPS: Attempts are made to elicit age, sex, race, occupation etc leading to a probable identification. 3) DNA PROFILING: This method is used when dental record is not available for comparison. The technique uses modern forensic DNA profiling methods to oral tissues to establish identity  ORAL AUTOPSY Autopsy is a highly specialized surgical procedure that consists of a thorough examination of a corpse to determine the cause and manner of death and to evaluate any disease or injury that may be present. Performed for either legal or medical purposes TYPES: 1. Forensic 2. Clinical or pathological 3. Anatomical 4. virtual RIGOR MORTIS LIVOR MORTIS DECOMPOSED BODY  Critical examination –gender, ethnicity, build, wounds, scars, tatoos Photographs, radiographs, fingerprints, finger nail scraping and hair sample may be obtained according to the requirements. Oral examination is an essential part of post mortem procedures Rigor mortis - use of mouth gags or intra oral myotomy is essential for jaw seperation. Thorough examination of soft tissues injuries, fractures, each tooth (carious, restored, missing) should be noticed.  MODIFIED INTERPOL POSTMORTE M ODONTOGRA PH  Obtaining dental records Dental records contain information of treatment undergone and dental status of a person during his/her life time and constitute the antemortem dental data. Content of all available records should be transcribed on to the standard ‘interpol antemortem form’ which is colour coded in yellow Comparing post mortem and ante mortem dental records Features compared include tooth morphology and associated bony structures, pathology and restorations An individual with multiple dental treatment and unusual features has a better likelihood of being identified than someone with no extraordinary dental characteristics RESULTS/ CONCLUSION: Positive identification: sufficient uniqueness among the comparable items. Probable identification: high level of concordance among datas, may lack radiograph support. Presumptive (possible) identification: enough information may be missing from either source. Insufficient identification: insufficient supportive evidence. Exclusion of identification: clearly inconsistent.  Problems with dental identification 1) Absence of antemortem records. 2) Absence of acquired dental tracts for identification. 3) Limitations for storing dental records for certain period. 4) Poor quality dental records. 5) In post mortem situation, all of the teeth may not be recovered as a result of post mortem trauma or loss of Pdl. 6) Fire can result in irreversible changes to restorations and teeth which can reduce the amount of information available for comparison.  Identification in mass disaster The term "mass disaster" evokes images of a chaotic event. The process of dental identification is same except the magnitude of event is far greater. Mass disasters can be classified in one of three ways: I. Natural Tsunami in 2004 2. Accidental 3. Criminal  Large number of human remains  Fragmented and  incinerated or commingled  Natural mass disasters include earthquakes, tornadoes, volcanic eruptions, fire storms and floods. Principal problem for the dental identification team → environmental infrastructure is often compromised. Dental offices containing antemortem records may be destroyed  Accidental mass disasters are most often associated with transportation accidents, fires, industrial and mining accidents, and military accidents. Occur over short periods, closed populations  INTENTIONAL MASS DISASTERS Bombing of buildings World trade center attack in 2001  According to clark, 50% of identification are from dental evidence. So odontology is a part of team. Clarke states- ‘dental examination is usually done after most other procedures such as photography, fingerprinting, and autopsy’. Postmortem unit is responsible for processing the radiograph and also need to arrange photography of teeth. Antemortem unit is most difficult. Dentist need to collect as mush information as possible in the shortest period of time. Comparison by- IDENTIFY, ODONTID, CAPMI, IDIS softwares. Reconstructive post mortem (dental profiling) Dental profiling includes extracting a triad of information- race, gender, occupation & age. According to Sweet and pretty- “The information from this process will enable a more focused search for ante mortem records”. IDENTIFYING ETHNIC ORIGIN FROM TEETH Traditionally, the human species has been categorized into three ‘races’ – Caucasoid, Mongoloid, Negroid. Many of the best traits of estimation of race are found in the mid facial skeleton, including the area of nose, mouth and cheek bones. Landmarks – a)shape of the cranium, b)lateral projection of zygomatic arches, c)shape and contour of the orbits and d)nasal aperture. GENETIC AND ENVIRONMENTAL INFLUENCES ON TEETH: Scott and turner suggest - dental features have evolved over time as a result of genetic and environmental forces that have influenced different population groups. complex mode of inheritance combination of hereditary factors and environmental effects to which a person is exposed. Dental features that have a stronger genetic and weak environmental influence are useful. Dental features – metric (tooth size) and non metric (tooth shape).  Metric features are based on measurements - considerably influenced by local environmental factors Non metric in terms of presence or absence of Two a particular feature - are more rooted upper inheritable.  Shovelling, premolar  Carabelli’s cusp, Two rooted upper molar  3 cusped maxillary 2nd molar Two rooted lower  4 cusped mandibular molars canine  Odontome  IDENTIFICATION FROM DENTAL DNA: Teeth can resist extreme condition. Pretty and Sweet state that teeth are an excellent source of DNA Applied technique → polymerase chain reaction- allows amplification of highly degraded DNA. This facilitates comparison with a known biological antemortem sample of the decedent such as hair from a comb, epithelial cells from a toothbrush or biopsy specimen. Advantage: - DNA pattern can be compared to the parents or siblings, thus facilitating positive identification  Types of DNA: Pretty and Sweet pointed out 2 types of DNA:  Genomic or Nuclear DNA: located in the nucleus of a cell and commonly used in nuclear studies.  Mitochondrial DNA: present in the mitochondria of cells.  Extraction of dental DNA: Tooth pulp is considered as the best source of dental DNA. Ajayprakash and co-workers isolated DNA from dental pulp and accurately determined personal identity using HLA-DQ amplification. Cytogenic grinding: Advocated by Sweet and Hildebrand. Technique: cooling the whole tooth to extremely low temperatures using liquid nitrogen mechanically grinding it to fine powder. sufficient amount of DNA (intact, carious as well root-filled teeth). Disadvantage: - tooth needs to be completely crushed.  According to Trivedi and coworkers  less destruction method for DNA isolation. opening of the root canals, scraping the pulp area with a notched medical needle subsequently flushing of the tissue debris.  This authors claim, ‘retains the morphology and physiology of the tooth’.  PALATAL RUGAE IN IDENTIFICATION: Palatal rugae are ridges on the anterior part of the palatal mucosa on each side of the mid- palatal raphe behind the incisive papilla A useful method of identification in edentate individuals. The rugae pattern on the deceased’s maxilla or maxillary denture may be compared to old dentures well protected by lips, check, tongue, buccal pad of fat and teeth in incident of fire and high impact trauma.  Can resist decomposition to an extent Unique to an individual. Seldom change shape with age and reappear after trauma or surgical procedures. Classification of palatal rugae: Acc to lysell, Primary rugae (>5mm) Secondary rugae (3-5 mm) Fragmentary rugae (2