Podcast
Questions and Answers
What does the term "forensic" mean?
What does the term "forensic" mean?
Legal
Who is considered the "Father of Forensic Odontology"?
Who is considered the "Father of Forensic Odontology"?
Dr. Oscar Amoedo
What are the three major fields of activity in forensic odontology?
What are the three major fields of activity in forensic odontology?
What is the scientific term for the study of enamel rod end patterns?
What is the scientific term for the study of enamel rod end patterns?
Signup and view all the answers
Dental evidence is the method of choice for establishing the identity of badly burned individuals.
Dental evidence is the method of choice for establishing the identity of badly burned individuals.
Signup and view all the answers
Which of the following is NOT a reason for the identification of human remains?
Which of the following is NOT a reason for the identification of human remains?
Signup and view all the answers
What is the term for the total of all characteristics of the teeth and their associated structures that, while not individually unique, create a unique whole?
What is the term for the total of all characteristics of the teeth and their associated structures that, while not individually unique, create a unique whole?
Signup and view all the answers
What is the general orientation of enamel rods in relation to the dentin surface?
What is the general orientation of enamel rods in relation to the dentin surface?
Signup and view all the answers
The shape of the human species has been categorized into only two races.
The shape of the human species has been categorized into only two races.
Signup and view all the answers
Which of the following features are commonly used to identify ethnic origin?
Which of the following features are commonly used to identify ethnic origin?
Signup and view all the answers
What are the two main types of DNA?
What are the two main types of DNA?
Signup and view all the answers
The success rate of determining sex using the mandibular canine index (MCI) is about 94%.
The success rate of determining sex using the mandibular canine index (MCI) is about 94%.
Signup and view all the answers
What is the most commonly used acid to condition enamel for in-vivo studies?
What is the most commonly used acid to condition enamel for in-vivo studies?
Signup and view all the answers
What method is used to make replicas of acid-etched mineral surfaces?
What method is used to make replicas of acid-etched mineral surfaces?
Signup and view all the answers
What type of forensic analysis software can be used to compare dental prints for similarities and dissimilarities?
What type of forensic analysis software can be used to compare dental prints for similarities and dissimilarities?
Signup and view all the answers
Fingerprints are considered a long-term marker of human identity.
Fingerprints are considered a long-term marker of human identity.
Signup and view all the answers
What is the term for the condition characterized by the absence of fingerprints?
What is the term for the condition characterized by the absence of fingerprints?
Signup and view all the answers
What are the three basic fingerprint patterns?
What are the three basic fingerprint patterns?
Signup and view all the answers
Fingerprints undergo significant changes after death, making them unreliable for identification.
Fingerprints undergo significant changes after death, making them unreliable for identification.
Signup and view all the answers
What is the term for any act of commission that endangers or impairs a child's physical or emotional health?
What is the term for any act of commission that endangers or impairs a child's physical or emotional health?
Signup and view all the answers
The majority of child abusers are strangers to the children.
The majority of child abusers are strangers to the children.
Signup and view all the answers
The oral cavity is not a common site for physical abuse in children.
The oral cavity is not a common site for physical abuse in children.
Signup and view all the answers
What type of injury is often seen in the oral cavity of child abuse victims?
What type of injury is often seen in the oral cavity of child abuse victims?
Signup and view all the answers
Healed bite marks can be an indication of child abuse.
Healed bite marks can be an indication of child abuse.
Signup and view all the answers
Documentation of child abuse should include which of the following?
Documentation of child abuse should include which of the following?
Signup and view all the answers
What is the purpose of using radiographs in forensic dentistry?
What is the purpose of using radiographs in forensic dentistry?
Signup and view all the answers
Radiographs can be used to determine the age of a victim by assessing the stage of tooth eruption.
Radiographs can be used to determine the age of a victim by assessing the stage of tooth eruption.
Signup and view all the answers
Which of the following factors can influence the appearance of a bite mark?
Which of the following factors can influence the appearance of a bite mark?
Signup and view all the answers
Infants bruise more easily from bite marks than adults.
Infants bruise more easily from bite marks than adults.
Signup and view all the answers
What is the name of the condition characterized by a lack of sensitivity to pain?
What is the name of the condition characterized by a lack of sensitivity to pain?
Signup and view all the answers
What are the three main categories used to classify bite marks?
What are the three main categories used to classify bite marks?
Signup and view all the answers
The use of lipsticks has become less important in crime scenes due to the development of lipsticks that leave no visible trace.
The use of lipsticks has become less important in crime scenes due to the development of lipsticks that leave no visible trace.
Signup and view all the answers
What is the term for the study of lip prints?
What is the term for the study of lip prints?
Signup and view all the answers
What is the key tooth for personal identification in sex determination based on tooth size?
What is the key tooth for personal identification in sex determination based on tooth size?
Signup and view all the answers
In the context of dental age estimation, what is the term for the regressive change that occurs with advancing age and is characterized by a translucent appearance of root dentin?
In the context of dental age estimation, what is the term for the regressive change that occurs with advancing age and is characterized by a translucent appearance of root dentin?
Signup and view all the answers
Study Notes
Forensic Odontology
- Forensic odontology is a branch of forensic medicine
- It deals with the handling and examination of dental evidence
- It encompasses the evaluation and presentation of dental findings
- It's a vital area in the interest of justice
- Forensic odontology involves the management, examination, and evaluation of dental evidence in criminal or civil proceedings
Historical Evidence
- Dr. Oscar Amoedo from Paris is considered the "Father of Forensic Odontology"
- Dental evidence played a crucial role in the identification of Adolf Hitler
- Dentition was a significant factor in identifying various leaders, including Zia Ul Haq and Rajiv Gandhi
Scope and Purpose
- Management and maintenance of compliant dental records
- Identification of human remains by comparing antemortem and postmortem dental information
- Collection and analysis of patterned marks (bite marks) on inanimate or injured tissue
- Recognition of signs and symptoms of human abuse
- Assessment of the person’s age
- Determination of the person’s sex
Reasons for Identification
- Criminal: A crime investigation can't proceed until the victim is identified.
- Marriage: Many religious backgrounds require deceased partners' identities to be confirmed for remarriage.
- Monetary: Payment of pensions, life insurance, or other benefits often requires positive death confirmation.
- Burial: Some religions necessitate positive identification before burial in designated locations.
- Social: Preserving human rights and dignity demands positive identification after death.
- Closure: Identifying missing individuals brings relief to family members.
Personal Identification
- Identification means establishing a person's individuality
- Characteristics by which a person can be recognized are considered personal identification factors
- Traditional methods involve visually recognizing the body or personal items
- Identifying burned or decomposed bodies can be challenging
Analyze Physical features
- Physical features include inherited and acquired characteristics
- Inherited features include ethnicity
- Acquired features involve surgical scars, fractures and dental restorations
Basis for Dental Identification
- Human dentition is unique in each individual
- Morphology and arrangement of teeth vary between persons
- Dental identity is a combination of all characteristics of teeth and their associated structures
- Teeth are resistant to environmental factors after death
Techniques of Identification
- Comparative Dental Identification: Comparing the deceased's teeth to existing records. This involves obtaining dental records, comparing postmortem and antemortem data, and writing a report and conclusions.
- Reconstructive Groups: Using available data (age, sex, race, occupation, etc.) to make a probable identification.
DNA Profiling
- This method is utilized when dental records aren't available.
- This uses modern forensic DNA profiling for oral tissues to establish identity
Oral Autopsy
- Oral autopsy is a specialized surgical procedure
- It involves a thorough examination of a corpse
- The aim is to determine the cause and manner of death as well as evaluate any injuries or diseases present
- It is performed for legal or medical purposes
Critical Examination
- Critical examination of remains includes observations of gender, ethnicity, build, wounds, scars, and tattoos
- Photographs, radiographs, fingerprints, and fingernail scrapings, along with hair samples, are collected as required.
- Oral examination is key in post-mortem procedures.
- Jaw separation requires oral myotomy (gags) due to rigor mortis.
Dental Status of Human Remains (Form)
- A form is provided for recording specific dental characteristics for documentation
Obtaining Dental Records
- Dental records document treatments and dental status of a person during their lifetime.
- These records are important antemortem data and should be transcribed onto a standard Interpol antemortem form.
Comparing Post Mortem and Ante Mortem Records
- Comparing postmortem with antemortem records is important
- Tooth morphology and associated bony structures, as well as pathology, are among the factors to consider.
- Individuals with significant previous dental treatment and unusual features are easier to identify
Results/Conclusion
- Positive Identification: Unique, matching characteristics between the comparable items.
- Probable Identification: High concordance between data, lacking radiographic support.
- Presumptive (Possible) Identification: Missing info.
- Insufficient Identification: Lack of supportive evidence.
- Exclusion of Identification: Clearly inconsistent features.
Problems with Dental Identification
- Absence of antemortem records,
- Absence of acquired dental tracings,
- Limitations to records storage duration or poor quality of records,
- Loss of PDL (periodontal ligament) after death,
- Damage to restorations or teeth.
Identification in Mass Disaster
- Mass disasters are often chaotic events.
- Dental identification process is similar to other cases but with greater magnitude.
- Mass disasters are classified as natural, accidental, or criminal.
- Large numbers of fragmented or incinerated remains are typical scenarios
Natural Mass Disaster
- Natural mass disasters include disasters like earthquakes, tornados, volcanic eruptions, firestorms, and floods
- Environmental infrastructure is often compromised.
- Dental records containing antemortem records may be destroyed.
Accidental Mass Disaster
- Accidental mass disasters are often associated with incidents like transportation accidents, fires, and industrial accidents
- These accidents usually affect a closed population and occur over short time periods
Intentional Mass Disaster
- Intentional mass disasters typically include incidents like bombing of buildings or attacks like the World Trade Center attacks
Forensic Odontology Team
- 50% of identifications are from dental evidence
- Dental examinations are usually done after other procedures like photography, fingerprinting, and autopsy.
- The postmortem unit handles dental radiographs and arranging photos
- The antemortem unit collects as much relevant information as possible quickly.
- Software like IDENTIFY, ODONTID, CAPMI, and IDIS helps analyze and compare data
Reconstructive Post Mortem (Dental Profiling)
- Dental profiling determines race, gender, occupation, and age.
- This information aids in narrowing searches for antemortem records.
Identifying Ethnic Origin from Teeth
- Traditionally, humans are categorized into Caucasian, Mongoloid, and Negroid races.
- Traits for race estimation are found in the middle facial skeleton (nose, mouth, and cheek bones).
- Landmarks include the shape of the cranium, lateral projection of zygomatic arches, shape and contour of the orbits, and nasal aperture.
Genetic and Environmental Influences on Teeth
- Dental features have evolved over time due to genetic and environmental factors.
- There's a complex inheritance pattern, affecting populations.
- Environmental factors, along with hereditary factors, strongly influence features.
- Some features have stronger genetic influences than environmental ones.
- Dental features, like tooth size (metric), and tooth shape (non-metric), are important
Metric and non-metric features
- Metric features are based on measurements, strongly influenced by environmental factors
- Non-metric features involve the presence/absence of specific traits, further analyzed in relation to the upper/lower premolar/molars, canine, and upper central incisors
Identification from Dental DNA
- Teeth resist extreme conditions
- Teeth are a good DNA source.
- Polymerase chain reaction (PCR) allows amplification of DNA from degraded sources.
- DNA can be compared to antemortem sources like hair, epithelial (cells)
- This technique provides a useful advantage for identification of parents, siblings, etc., from biological records
Types of DNA
- Genomic or Nuclear DNA is found in cell nuclei.
- Mitochondrial DNA is present in cell mitochondria.
Extraction of Dental DNA
- Tooth pulp is considered the best source for dental DNA.
- Ajayprakash and coworkers isolated DNA from tooth pulp for accurate personal identification via HLA-DQ amplification
Cytogenic Grinding
- This method, advocated by Sweet and Hildebrand, cools the whole tooth using liquid nitrogen for grinding into powder.
According to Trivedi and coworkers, there's a less destructive method for DNA isolation
- This includes opening root canals, scraping the pulp area, and flushing out debris, retaining the tooth’s morphology and physiology
Palatal Rugae in Identification
- Palatal rugae are ridges on the palate.
- Rugae pattern is useful for identification, especially in individuals with no existing teeth.
- They're often protected from damage in incidents involving fire or high impact trauma.
- Classification of rugae includes primary (>5mm), secondary (3-5mm), and fragmentary (2<3 mm) rugae.
Analysis of Rugae Pattern
- Thomas and Van Wyk traced rugae from dentures to clear acetate, then superimposed on photographs of plaster models.
- Software methods have aided in accurately analyzing rugae.
Sex Differentiation
- Sex can be determined from skull and mandible morphology, metric features of the skull and teeth, and DNA analyses.
Sexing from Craniofacial Morphology and Dimension
- Sex determination is often not reliable until puberty.
- Multiple features for accurate sex determination.
- Williams and Rogers used 6 craniofacial traits for 94% accuracy in sex determination.
Sex Differences in Tooth Size
- Measuring mesiodistal and buccolingual dimensions help differentiate sex.
- Teeth like canines, premolars, and molars show significant sex differences.
Dental Index
- Mandibualar canines exhibit significant sexual dimorphism in teeth
- Mandibular canines are less affected by plaque, calculus, abrasion, and periodontal disease (they're often the last tooth extracted).
- They are critical for personal identification.
Cut-off points/standard MCI (mandibular canine index) value
- The cut-off point obtained for MCI value is 0.274 (by Rao et al.)
- Teeth with an MCI less than or equal to 0.274 suggest a female.
- Teeth with an MCI greater than 0.274 suggest a male.
Dental Age Estimation, Prenatal, Neonatal, Early Postnatal
- Dental age is a significant physiologic development measure.
- Dental age is applicable from infancy to late adolescence
- Estimation phases: prenatal, neonatal, early postnatal, children, adolescents, and adults.
Age Estimation in Children and Adolescents
- Tooth emergence (eruption) and calcification are key events for age estimation.
- Deciduous teeth exhibit genetic control for emergence (approximately 6–2.5 years).
- Permanent teeth are influenced by oral environment and premature tooth loss
Evaluation of Radiographs
- Radiographs are a superior tool for evaluating tooth calcification due to its ability to continuously track calcification for several years.
- They aren't affected by local factors
- Assessment is helpful in age groups where tooth emergence isn't yet visible (e.g., 2.5–6 years or over 12 years)
Demirjian's Method
- Seven mandibular teeth are used for age estimation in children and adolescents
- The teeth' developmental stages are from A (mineralized cusp tips) to H. (apices completely closed)
Third Molars in Age Estimation
- Third molars are important indicators for identifying persons aged 16-23.
- 4 completely calcified third molars suggest the individual likely is 18 years old (96.3% chance for accurate determination for both males and females).
- The presence of one or two third lower molars is highly suggestive of a 18 year old.
Age Estimation in Adults
- Age estimation in adults is challenging due to diverse lifestyle factors, like diseases, nutrition, and physical strain.
- Gustafson's method, dentin translucency, incremental cement lines, and amino acid racemization are methods to consider.
- The radiographic method by Kvaal also provides useful age estimation.
Gustafson's Method (for Age Estimation in Adults)
- Gosta Gustafson, in 1950, developed an adult age estimation method based on morphological/histological changes observed in teeth.
- Regressive changes such as occlusal attrition, secondary dentin deposition, periodontal attachment loss are evaluated.
- Data from the changes calculated using a formula such as: Age = 11.43 + 4.56X (with X being the assessed regressive change value)
Dentinal Translucency (for Age Estimation in Adults)
- Root dentin becomes translucent after the third decade
- Dentin translucency starts at the apex and progresses coronally
- Increasing diameter of dentinal tubules, and intratubular calcification, increases dentin translucency
- This method is significant for age estimation, recognized by Johnson.
- Bang and Ramm noted increased root translucency with advancing age
Age Estimation from Incremental Lines of Cementum (for Age Estimation in Adults)
- The method by Kagerer and Grupe uses acellular cementum incremental lines to reliably estimate age.
- Mandibular central incisors or third molars' mineralized, unstained cross-sections are used
- This method generally provides age accuracy to within 2-3 years
Radiographic Method of Kvaal (for Age Estimation in Adults)
- Pulp size measurements from specific teeth are utilized in Kvaal's radiographic method for establishing age.
- Teeth examined include maxillary central and lateral incisors, second premolar, mandibular lateral incisor, canine, and first premolar.
- Pulp-root length, pulp-root width, and tooth-root length measurements are necessary for the age estimation.
Amino Acid Racemisation (for Age Estimation in Adults)
- This is based on rate of racemisation of aspartic acid in teeth.
- The racemisation rate of aspartic acid is significant in root dentin.
- The change in ratio of L- and D-aspartic acid with increasing age is used for age estimation.
- This method offers estimated age accuracy to within 3 years of the actual age.
Key to Optimal Dental Estimation
- Experienced investigators, second opinions, multiple methods (not just one), multiple teeth and following established protocol are crucial for reliable dental estimations
Bite Marks
- Bite marks are marks made by teeth, either alone or with other mouth parts.
- These marks are defined as the pattern left on a surface or tissue by a person’s or animal’s dentition.
- In cases of sexual assault, including homicide, rape, and child abuse, bite marks regularly appear around areas associated with sexuality.
Classification of Bite Marks:
- Cameron and SIMS Classification: Based on the agent (human/animal) and material (skin/body tissue/food).
- Mac Donald's Classification: Identifies specific types of bite marks (pressure, scrape, tongue marks) based on the method of bite inflicted -Webster’s classification for foodstuff-theft/robbery bite marks differentiates marks based on the impact on the food item, from fractures to penetration and slide marks
Description of Some Types of Bite Marks
- Sexually-Oriented Bites: Slow, deliberate, and often characterized by suction marks.
- Child Abuse Cases: May exhibit aggressive or sexually oriented patterns.
- Self-Inflicted Bites: Often found on forearms of children (self-injuries), and mentally disturbed individuals also self inflict injury
- Lesch-Nyhan Syndrome: A rare disorder is characterized by insensitivity to pain, thus leading to frequent self-inflicted bites.
Identifying Injury as a Bite Mark
- Gross features include circular/elliptical shape, ecchymosis in center.
- Class features distinguish between teeth types (incisors, canines, premolars, molars); shapes vary with tooth type.
- Individual features in teeth include fractures, rotations, and spacing, which provide even more detailed unique characteristics
Sites of Bite Marks
- Female victims' bites typically are on breasts, abdomen, thighs, buttocks, and pubic areas.
- Male victims' bites usually include the back, arms, shoulders, and chest/pubic area.
- Cases involving self-defense, victims might have bite marks on the assailant's hands or arms
Factors Influencing Bite Marks
- Tissue Type: Loose or fatty tissues cause poor definition, and fibrous/muscle-rich tissues result in better-defined marks.
- Age: Children & older adults bruise more easily than adults, affecting bite-mark visibility.
- Sex: Females exhibit longer-lasting bite marks than males.
- Medical Status: Medical conditions (like anticoagulant therapy or skin disease) can change bruising characteristics.
- Time: Bite mark effects typically diminish (swelling, discoloration) within 10–20 minutes
Bite Mark Cases -- Step-by-Step
- Step 1: Description of bite marks (shape, size, color, etc.)
- Step 2: Evidence collection from the victim (often with photographs)
- Step 3: Evidence collection from the suspect (including dental models/photography)
- Step 4: Bite mark comparison to determine if the marks match suspect’s bite patterns.
Data Collection From The Victim
- Visual assessment of the bite mark location, contours, texture, and physical appearance.
- Photography of bite marks (orientation & close-up) is critical for documentation, especially in cases where the victim is deceased
- Saliva swabbing, when possible, can provide a DNA link
Examination of the Suspect
- Obtaining dental history (treatments, injuries).
- Photographs of their face, frontal, occlusal, lateral dental arch and teeth need to be recorded
- Examination of the TMJ (temporomandibular joint), facial, muscle tone, and maximum mouth opening/movement should be documented
- Recording the periodontal (tissues around the teeth), and tooth arrangements with saliva swabbing.
- Dental models should be prepared for possible future comparison.
Evaluation of Evidence
- Determining if bite marks are from human or nonhuman sources is essential
- Characteristics need to be analyzed critically for match confirmation
Histopathological Changes in Bite Marks
- Bite marks' histopathological changes alter over time with stages including scab formation, epithelial regeneration, subepidermal granulation, and regression.
Methods of Bite Mark Analysis
- Odontometric Triangle Method: Three points define a triangle using bite and dental model tracings, matching to areas of upper and lower canine teeth, and central incisors;
- Metric Analysis: Utilizes Vernier calipers or computer digitization methods to measure bite & suspect’s teeth' dimensions.
Pattern Association
- Direct Method: Suspect’s model is directly superimposed over the victim's bite marks photo.
- Indirect Method: Traces of suspect’s teeth are transferred to clear acetate for superimposition.
Conclusions of Bite Mark Analysis
- Positive Identification: Matches between bite mark and suspect's teeth.
- Possible Identification: Bite mark could match suspect but no conclusive characteristics.
- Exclusion of Identification: Bite mark shows that suspect’s teeth definitely do not match.
Cheiloscopy
- Lip prints’ study (cheiloscopy) aids in human identification.
- Lip prints are needed within 24 hours of death
- Accuracy depends on mouth position (open/closed) when the lip print occurred.
- Different classifications, like Santos (1967) and Suzuki and Tsuchihashi (1970) exist for lip prints.
Ameloglyphics
- The study of enamel rod end patterns is called ameloglyphics.
- Enamel rods are the basic structural units of enamel.
- Tooth prints are unique and aid forensic identification of otherwise unrecoverable bodies.
Classification of Lip Prints
- Simple Wrinkles include straight, curved, angled, and sine-shaped grooves.
- Compound Wrinkles involve bifurcated, trifurcated, or anomalous patterns.
- Suzuki and Tsuchihashi (1970): Types I, I', II, III, IV, and V for different lip print types
Radiological Methodology in Forensic Odontology
-
Radiographs are crucial for accurate identification
-
They aid in determining the age of victims (stages of tooth eruption) and identifying potentially concealed injuries in teeth/body
-
Radiographs are useful in identifying bullets or other foreign objects that might be present in trauma or death victims
-
Faulty teeth charting during postmortem data collection or recording needs to be considered
-
Expert witness testimony should be clear, simple, and straightforward
Conclusion
- Forensic scientists are responsible for gathering, preserving, and interpreting evidence, relaying findings clearly to legal authorities.
- Forensic odontology deals with dental evidence for identification purposes.
- Dental records during patients’ treatment can assist in legal identification processes and should be properly documented
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz explores the critical field of forensic odontology, which involves the examination and evaluation of dental evidence within legal contexts. Learn about the historical significance, key figures, and the scope of dental identification methods used in criminal and civil investigations. Test your understanding of how dental records and bite mark analysis contribute to justice.
