Exam 3 Flashcards
Population Variation (4 types)
1) age
2) sex
3) ancestry
4) stature
Individual Variability (4 types)
1) Normal Anatomical
2) Skeletal Anomalies
3) Pathological Conditions
4) Repetitive Mechanical Stress
Differential Diagnosis (def)
systematic method for narrowing down the identity of a condition
Pathogenesis (def)
process by which a disease forms/develops
Pathology - def & 2 important people)
(def) study of disease
1) Earnest A Hootan: epidemiological approach
2) Marc Armand Ruffer: paleopathology (egyptian mummies)
Pathology Limitations in Forensics (4)
1) most diseases have no affect on bone
2) different diseases leave the same effects
3) few disease are pathognomonic on bone
4) etiology (cause of disease) is not often the cause of death
Antemortem Conditions (4)
1) Identification
2) time since injury
3) reconstruction of behaviors (MSM)
4) differentiates normal/abnormal skeletal morphology
Proliferative Signs
(def of peri + osteom)
(def) umbrella term for various skeletal conditions
1) periostitis: term for unspecified infection
2) Osteomyelitis: sign of nonspecific bacterial infection
Periostitis vs Osteomyelitis (def) (PF)
Peri: term for unspecified disease
Osteo: sign of nonspecific bacterial infection
Lytic Lesions & Osteoporosis
LL: eating away of the bone
Osteo: lower than normal bone density
Reformative Lesions (2 types)
1) Rickets: bowing of legs due to lack of vitamin D
2) Scoliosis/Kyphosis: abnormal curving of spine
Dental Pathologies (2 types)
1) Dental Caries (cavaties)
2) enamel hypoplasia: line on tooth from stunted growth
Musculoskeletal Stress Markers (MSM/MSO)
repetitive mechanical stress on the bone (from work, sports, etc)
Methods of Personal ID (5)
1) biological profile
2) skeletal dental anomalies
3) radiographs
4) surgical implants
5) DNA (nuclear/mitochondria)
FA trauma consults can determine… (6)
1) mechanism of trauma/MOD
2) timing of trauma (anti, peri, post)
3) directionality
4) # of events
5) sequence of events
6) possible tool (class) ID
Tentative & Presumptive ID (3)
1) based on context/association
2) strong consistencies w/ remains of suspected ID
3) circumstantial ID
Levels of ID (5)
1) tentative
2) presumptive
3) probable (preponderance of evidence)
4) exclusion (evidence proves it is NOT individual)
5) positive
Mitochondrial Forensic DNA Typing
(def) used when primary DNA is nonexistent (ID from older/degraded samples)
- cannot result in a positive ID
- high mutation rate leads to high variability
Facial Approximation (overview and 2 people)
- computer reconstruction; low success rate; NEVER a positive ID
1) Wilhelm His: tissue depth method
2) Gerasimov: anatomical method
Photo Superimposition
imposes photo over a skull
- more accurate than facial approx.
- never a positive ID
ID by Exclusion
used for closed populations by process of elimination
-ex. plane crash victims, rule individuals out based on flight manifest
Comparative Radiography (RADid)
-Xrays, CTs, MRIs
-narrows down possibilities
-relies on skeletal variation
-used for exclusion
Dental Radiograph Comparisons (Forensic Odontology)
-must have suspected ID for comparison w/ dental records
-match dental Xrays
-limitations due to lack of dental care
Comparative Radiology
-must have suspected ID for comparison
-compares frontal sinuses
Problems w/ Comparison (based IDs) (4)
1) relies on evidence for skeletal variation
2) need an AM record
3) # of points of similarity
4) no current standards
Quantitative Methods of ID (def & 3 points)
(def) statistical means of assessing uniqueness of skeletal features
1) probability evidence supporting or disproving a hypothesis
2) population frequencies of variation
3) based on stats/calculations of posteriors probabilities
CODIS
Combined DNA Index System
- standardized database by FBI
- 3 levels (national, state, & local)
- 3 databases (unknown, past offenders, missing person)
NamUs
national missing and unidentified person system
Perimortem Trauma
(def) physical disruption of living tissue by outside force at/around the time of death
Viscoelastic vs Anrostopic
Viscoelastic: bendiness of bone before breaking
Anisotropic: having different mechanical properties in different directions
Types of Forces (4)
1) tension: pulling apart/stretching bone
2) compression: squeezing/pushing bone
3) shear: slides portion of bone
4) torsion: twisting of bone
Trauma Categories (4)
1) blunt force (BFT)
2) gun-shot (GST)
3) sharp force (SFT)
4) Thermal
Sharp Force Trauma
(def) narrow focused, dynamic, & slow compressive force w/ a sharp object
-beveled age & kerf
-1+ straight line
-knives/saws
-puncture wound
Thermal Trauma (4 reasons)
1) accidental
2) concealment of crime
3) concealment of identity
4) concealment of other trauma (BFT, SFT, GST)
Fire Trauma Issues (2)
1) recovery
2) distinguishing perimortem & antemortem injuries
Carbonization & Calcination
Carb: breakdown of organic molecules leaving carbon behind
Calc: loss of organic bone/carbon
Gunshot Wound Trauma (GSW) Features (3)
1) high velocity, small focal area
2) affects cranium vs postcranium differently
3) becomes BFT at low velocity
GSW Cranial Features (3)
1) radiating fxs
2) plug/spall defects
3) beveling
GST Reconstructions Indicate (4)
1) # of impacts
2) sequence (puppe’s law)
3) direction of fire/distance if close range
4) type/caliber of bullet
GSW Postcranium Features (3)
1) most variable, depend on bone thickness
2) entrances/exits are more irregular
3) false butterfly fractures
Blunt Force Trauma (BFT) (3)
1) slow loading impact to focal point
2) greater chance for bone bending
3) large amount of radiating/concentric fractures
Info Derived from BFT (5)
1) amount of energy/force
2) directionality
3) # of events
4) sequence of events
5) tool class
Signatures of non-accidental pediatric injury (4)
1) cranial/retinal hemorrhage
2) rib fracture of verbal ends
3) antemortem fxs (diff stages of healing)
4) Classic metaphysical lesions (CML’s)
Butterfly Fxs (BFT)
bending force causes tension/compression on opposite sides
