Forensic Odontology Textbook Chapter 4 (pp ) Handout, Chapter 2: Dental Identification (supplemental source) J. For. Sci.: Tenerife Revisited: the critical role of dentistry Teeth characteristics~ Crown, neck, rootCrown, neck, root 20 deciduous teeth: 10 maxillary, 10 mandibular arch20 deciduous teeth: 10 maxillary, 10 mandibular arch 2 incisors, 1 canine, 2 molars (5 teeth x 4 = 20 baby teeth)2 incisors, 1 canine, 2 molars (5 teeth x 4 = 20 baby teeth) 32 adult teeth: 16 maxillary, 16 mandibular arch32 adult teeth: 16 maxillary, 16 mandibular arch 2 incisors, 1 canines, 2 bicuspids (premolars), & 3 molars (8 teeth x 4 = 32 permanent teeth)2 incisors, 1 canines, 2 bicuspids (premolars), & 3 molars (8 teeth x 4 = 32 permanent teeth) Number of roots depends on tooth type & location (upper –vs- lower arch)Number of roots depends on tooth type & location (upper –vs- lower arch)

Teeth Characteristics (cont.) Teeth characteristics~ Dentine= calcified connective tissue w/ Ca 2+ salts ~70% dry wgtDentine= calcified connective tissue w/ Ca 2+ salts ~70% dry wgt Layer of enamel (95% Ca 2+ salts) covers crownLayer of enamel (95% Ca 2+ salts) covers crown Layer of bone-like cementum covers rootLayer of bone-like cementum covers root Center of tooth is the pulp cavity, containing connective tissue, bld vessels, nerve endingsCenter of tooth is the pulp cavity, containing connective tissue, bld vessels, nerve endings Emergence of 2 sets of dentitions~ Deciduous teeth: ~6 months first emergence occurs, then a pair monthly until 20 teeth have eruptedDeciduous teeth: ~6 months first emergence occurs, then a pair monthly until 20 teeth have erupted Begin loosing baby teeth ~6 yrs until ~12 yrs, while being replaced w/ permanent teethBegin loosing baby teeth ~6 yrs until ~12 yrs, while being replaced w/ permanent teeth Permanent teeth: additional molars erupt Wisdom teeth (3 rd molars) may erupt after ~17 yrs, or not at all

When to Use a Forensic Odontologist Identifications~ Victim is decomposed, mutilated, burned, or skeletonized such that photo/visual ID is of no assistanceVictim is decomposed, mutilated, burned, or skeletonized such that photo/visual ID is of no assistance Dentition may be virtually unaffected & ID made w/ great certaintyDentition may be virtually unaffected & ID made w/ great certainty Other forms of ID produce conflicting conclusionsOther forms of ID produce conflicting conclusions No fingerprints available (ante- or postmortem)No fingerprints available (ante- or postmortem) Dental records can be obtainedDental records can be obtained Bone trabeculation patterns &/or sinus cavity configuration of edentulous (no teeth) or partially edentulous victims can provide possible-to-positive IDBone trabeculation patterns &/or sinus cavity configuration of edentulous (no teeth) or partially edentulous victims can provide possible-to-positive ID

When to Use a Forensic Odontologist Identifications (cont.)~ Estimation of ageEstimation of age ‘neonatal line’: enamel deposited in a series of striae‘neonatal line’: enamel deposited in a series of striae Subadult emergence of teeth (Table 4.1)Subadult emergence of teeth (Table 4.1) Potential to age individual teeth??Potential to age individual teeth?? Gender and racial originGender and racial origin Difficult to ID gender, yet DNA in pulp may possibly availableDifficult to ID gender, yet DNA in pulp may possibly available Some morphological (slight) differences can be used as traits to suggest raceSome morphological (slight) differences can be used as traits to suggest race Shovel-shaped incisors of mongoloid ancestryShovel-shaped incisors of mongoloid ancestry Dentition, mandibular arch, etc.Dentition, mandibular arch, etc.

When to Use a FO (cont.) Mass Fatalities~ Lrg # of IDs occur simultaneously, sorting & ID of possible co- mingled remainsLrg # of IDs occur simultaneously, sorting & ID of possible co- mingled remains Bitemark Evidence~ Child abuse, rape, aggravated assaults, homicidesChild abuse, rape, aggravated assaults, homicides Comparison of teeth (& position in arch) can provide:Comparison of teeth (& position in arch) can provide: Aging of 2+ bitesAging of 2+ bites Inclusion or exclusion of an individual from a grp of possible bitersInclusion or exclusion of an individual from a grp of possible biters Determination of human –vs- non-humanDetermination of human –vs- non-human Analysis of other materials (gum, food, non-foodstuffs) that may have been bitten & crime sceneAnalysis of other materials (gum, food, non-foodstuffs) that may have been bitten & crime scene FO should inspect potential victim bite(s) on the suspected perpetrator, thus, preserving the bitemark evidenceFO should inspect potential victim bite(s) on the suspected perpetrator, thus, preserving the bitemark evidence Photograph & study models of the victim’s dentitionPhotograph & study models of the victim’s dentition

When to Use a FO (cont.) Child Abuse~ Examination of intraoral & extraoral injuries, as well as, pre- existing oral conditions indicating neglect or previous traumaExamination of intraoral & extraoral injuries, as well as, pre- existing oral conditions indicating neglect or previous trauma Bitemarks found on child abuse victims should be photographed & documented immediately by a FO to preserve the evidenceBitemarks found on child abuse victims should be photographed & documented immediately by a FO to preserve the evidence Other~ Pieces or a whole tooth found at a crime scene can be analyzed regarding:Pieces or a whole tooth found at a crime scene can be analyzed regarding: Human or animal; belonging to victim or perpetrator; & potentially placing individual(s) at the crime sceneHuman or animal; belonging to victim or perpetrator; & potentially placing individual(s) at the crime scene Estimations of age, sex, & ethnicityEstimations of age, sex, & ethnicity Charting dental info for unID persons into federal computer program (FBI) for use of comparing missing persons dataCharting dental info for unID persons into federal computer program (FBI) for use of comparing missing persons data

Scientific Methods of ID Visual~ Not scientific & often unreliable, but most frequent means of IDNot scientific & often unreliable, but most frequent means of ID Fingerprints~ Most widely method used if available, but begin to deathMost widely method used if available, but begin to death Requires previous record (antemortem) & sufficient postmortem fingerprint materialRequires previous record (antemortem) & sufficient postmortem fingerprint material DNA~ New technology that will eventually replace dental & fingerprint IDs as the most definitive means of identifying remainsNew technology that will eventually replace dental & fingerprint IDs as the most definitive means of identifying remains BUT expensive & time consumingBUT expensive & time consuming Must have antemortem genetic material for positive ID (material from family members only prove relationship)Must have antemortem genetic material for positive ID (material from family members only prove relationship) Methods exist for extracting DNA from teethMethods exist for extracting DNA from teeth

Scientific Methods of ID (cont.) Dental~ A scientifically reliable method of ID providing the greatest accuracy in the most timely mannerA scientifically reliable method of ID providing the greatest accuracy in the most timely manner Postmortem changes are very slow…thus, survivability of dental evidence is tremendousPostmortem changes are very slow…thus, survivability of dental evidence is tremendous Resistant to environmental effects & destruction by fire (i.e., can w/ stand harsh environments)Resistant to environmental effects & destruction by fire (i.e., can w/ stand harsh environments) Found intact in fires ~1600 o F due to protections by soft tissue & alveolar boneFound intact in fires ~1600 o F due to protections by soft tissue & alveolar bone Dental restorations & prostheses even more resistant to physical & chemical deteriorationsDental restorations & prostheses even more resistant to physical & chemical deteriorations Potentially infinite # of points of comparison (i.e., individual characteristics)Potentially infinite # of points of comparison (i.e., individual characteristics) Each tooth could be: unrestored, restored, missing; the 160 tooth surfaces may have restorations, prosthetic applicances, etc.; tooth/crown morphology, pulp/root formEach tooth could be: unrestored, restored, missing; the 160 tooth surfaces may have restorations, prosthetic applicances, etc.; tooth/crown morphology, pulp/root form

Scientific Methods of ID (cont.) Dental (cont.)~ Excellent antemortem data base since large % of general pop visits a dentistExcellent antemortem data base since large % of general pop visits a dentist Routinely take radiographs and make dental records which detail antemortem dental conditionsRoutinely take radiographs and make dental records which detail antemortem dental conditions Records are usually maintained for long periods of time & radiographs provide ‘hard’ evidence not subject to human errorRecords are usually maintained for long periods of time & radiographs provide ‘hard’ evidence not subject to human error Relatively fast & easy to obtainRelatively fast & easy to obtain Skeletal Remains~ Comparisons of ante- & postmortem images (healed fractures, unique bone morphology, etc.)Comparisons of ante- & postmortem images (healed fractures, unique bone morphology, etc.) Anthropologist can estimate sex, age, raceAnthropologist can estimate sex, age, race

Scientific Methods of ID (cont.) Identification by Exclusion~ Method refers to comparison of postmortem data of deceased to known antemortem data from a finite # of suspect possibilitesMethod refers to comparison of postmortem data of deceased to known antemortem data from a finite # of suspect possibilites Not definite & used as a last resortNot definite & used as a last resort

Necessary Dental Information Data Gathering~ Antemortem data~ Dental x-rays, charts Military records, prison records Medical charts, x-rays Dental appliances, study models Postmortem data~ Dental remains collected from severely fragmented, decomposed, severely burned, or skeletonized bodies Charting & x-rays Data Comparison~ Identification based on comparison antemortem records to postmortem remains

Final Verification Positive ID~ Ante- & postmortem data match w/ sufficient detail to establish from same individualAnte- & postmortem data match w/ sufficient detail to establish from same individual No irreconcilable discrepanciesNo irreconcilable discrepancies Possible ID~ Ante- & postmortem data have consistent features, but due to quality of either postmortem remains or antemortem evidence, it’s not possible to positively establish dental IDAnte- & postmortem data have consistent features, but due to quality of either postmortem remains or antemortem evidence, it’s not possible to positively establish dental ID Insufficient ID~ Insufficient info available to form the basis of a conclusionInsufficient info available to form the basis of a conclusion Exclusion~ Ante- & postmortem data are clearly inconsistentAnte- & postmortem data are clearly inconsistent If victim is unidentified, then dental data submitted to program

Dental Radiographs Panorex~ Panoramic or whole mouth x-rayPanoramic or whole mouth x-ray Shows teeth & supporting bone, maxillary sinuses, TMJ, nasal aperature, & inferior eye orbitShows teeth & supporting bone, maxillary sinuses, TMJ, nasal aperature, & inferior eye orbit Bitewing X-rays~ Most common dental x-rayMost common dental x-ray Shows crown portion of posterior teethShows crown portion of posterior teeth May not show unerupted or impacted teeth, root canal treated teeth, or bone pathology & anomaliesMay not show unerupted or impacted teeth, root canal treated teeth, or bone pathology & anomalies Periapical X-rays~ Detailed x-rays of individual teeth that displays entire tooth & supporting boneDetailed x-rays of individual teeth that displays entire tooth & supporting bone

Equipment & Techniques for ID Equipment & personnel~ Dental identification kit (instruments & supplies)Dental identification kit (instruments & supplies) Dental forensic forms (ante- & postmortem forms, ID summary forms)Dental forensic forms (ante- & postmortem forms, ID summary forms) Portable x-ray unit & film developing/processing equipmentPortable x-ray unit & film developing/processing equipment Dental ancillary support (dental radiology techs, hygienists, assistants)Dental ancillary support (dental radiology techs, hygienists, assistants) Processing remains includes: Cleaned w/ H 2 O 2 or bleachCleaned w/ H 2 O 2 or bleach Thorough charting of existing oral & dental conditionsThorough charting of existing oral & dental conditions Radiology of remainsRadiology of remains Acquire antemortem recordsAcquire antemortem records

Points of Comparison Most common points for comparison~ # of teeth (lost teeth PM need to be noted)# of teeth (lost teeth PM need to be noted) Malposition & rotation of teethMalposition & rotation of teeth Restorations & prosthesesRestorations & prostheses Dental cariesDental caries Anomalous tooth formationAnomalous tooth formation Root canal therapyRoot canal therapy Bone patternBone pattern OcclusionOcclusion Oral pathologyOral pathology Occupational & socioeconomic pattern of dentitionOccupational & socioeconomic pattern of dentition