Chapter 17 — Self-Check Quiz

24 questions: multiple choice and short answer. Try them closed-book. The answer key is in the collapsed block at the bottom.

Multiple choice

1. Forensic odontology's one valid, reliable core contribution is: - A. Matching a suspect's teeth to a bite mark in skin - B. Identifying human remains by comparing antemortem dental records to a postmortem examination - C. Estimating time of death from tooth wear - D. Determining cause of death from the teeth

2. Teeth are the identifying tissue of last resort mainly because: - A. They are colorful and easy to photograph - B. Enamel is the hardest, most mineralized tissue in the body, so teeth survive fire, decomposition, water, and time - C. Everyone has exactly 32 of them - D. They contain a complete DNA profile that nothing else does

3. In a dental-identification comparison, the antemortem record is: - A. The examination the odontologist performs on the body - B. The "questioned" sample - C. The dental record created during the person's life (the "known" side) - D. A bite mark left at the scene

4. After intense fire, teeth become extremely friable, which means a recovery team must: - A. Rinse them immediately in water - B. Handle the jaws like ordinary bone to save time - C. Stabilize, document, and remove them slowly, because they can shatter at a touch - D. Discard fragmented teeth as useless

5. The same upper-right first molar is "3" in one system, "16" in another. This illustrates that: - A. The body has two of that tooth - B. Different numbering systems label the same tooth differently, so a chart that omits its system can be misread - C. The antemortem record is forged - D. Dental charts are meaningless

6. The best-case antemortem material for a confident identification is usually: - A. A billing record alone - B. The patient's verbal description of their teeth - C. Recent radiographs (X-rays), because they show roots, bone, and restorations and can be overlaid against postmortem films - D. A photograph of the person smiling

7. A tooth recorded as present in a two-year-old antemortem film is absent in the body. This is most likely: - A. An unexplainable discrepancy that excludes the identity - B. An explainable discrepancy — a tooth present earlier can be extracted since (present→missing is biologically possible) - C. Proof the records were swapped - D. Irrelevant to the comparison

8. A tooth recorded as extracted in the antemortem record is present and intact in the body. This is: - A. An explainable discrepancy - B. An unexplainable discrepancy that can exclude the identity (missing→present is not biologically possible) - C. A normal finding - D. Evidence of a positive identification

9. The most objective single technique in dental identification is: - A. Asking the family if it looks like their relative - B. Comparing two written charts side by side - C. Radiographic overlay — superimposing antemortem and postmortem films to compare root morphology, sinus outlines, and trabecular bone - D. Counting the total number of fillings

10. An "Identification (positive)" conclusion requires: - A. At least one matching filling - B. Concordant features of sufficient quantity and specificity, with no unexplainable discrepancies - C. A confession from a relative - D. A DNA match in addition

11. In Interpol DVI practice, the three primary identifiers are: - A. Clothing, jewelry, and tattoos - B. Fingerprints, dental records, and DNA - C. Eyewitness accounts, dental records, and personal effects - D. Facial recognition, dental records, and height

12. A single dental concordance is less discriminating in a 300-victim disaster than in a two-person problem because: - A. Teeth change in disasters - B. In a large enough pool, mouths with broadly similar restoration patterns occur by chance, so the candidate-pool size affects the strength - C. DVI does not use dental evidence - D. The math is identical regardless of pool size

13. Bite-mark comparison asks a fundamentally different question from dental identification, namely: - A. Whose body is this? - B. Did this person's teeth make this mark in skin? - C. How old is the decedent? - D. What did the victim eat?

14. The decisive reason bite-mark comparison fails where dental identification succeeds is the substrate and the premise: - A. Bite marks are compared against stable, mineralized teeth and a documented record - B. Bite marks are compared against human skin — which stretches, swells, bruises, and heals — under an unvalidated premise that skin faithfully records a unique dentition - C. Bite marks use radiographic overlay - D. There is no difference

15. On the NAS 2009 / PCAST 2016 validity spectrum, dental identification is best placed as: - A. At the very top, identical in rigor to single-source DNA - B. Fully discredited, like bite marks - C. A valid, sound method in the better-grounded middle — below rigorously quantified DNA, well above bite marks — with error dominated by human factors - D. Having no scientific basis

16. The structural confirmation-bias trap in dental identification is that: - A. Odontologists are paid by the body - B. The work almost always begins with a presumed identity, so the examiner usually knows the answer they are expected to produce - C. Teeth cannot be charted objectively - D. Antemortem records are always missing

17. In the cold case, the dental identification most defensibly establishes: - A. Who killed Marcus Diallo - B. When and how Diallo died - C. That the burned body is Marcus Diallo (closing the "someone else's body" fraud theory) - D. That the fire was arson

18. A board certification in forensic odontology, by itself, tells a juror: - A. That all of the witness's testimony is valid - B. Nothing about whether a particular claim is valid — the credential does not travel with the validity of the specific task - C. That bite-mark testimony is reliable - D. That the witness cannot be cross-examined

Short answer

19. Explain, in two sentences, why dental identification's power is a property of "teeth plus a record," not teeth alone. Give one case in which odontology would be defeated despite a perfectly intact dentition.

20. State the directional rule that distinguishes an explainable from an unexplainable dental discrepancy, and explain why that rule is a logical check the method "leans on heavily."

21. Why can a single unexplainable discrepancy exclude an identity more confidently than a dozen concordant restorations can establish one? Connect this to the book's "exclusion over proof" theme.

22. The same expert specialty produces valid identification and discredited bite-mark testimony. State the one question a juror, attorney, or judge should ask instead of "Is this witness a qualified odontologist?"

23. In the cold case, the dental identification confirmed the victim is Marcus Diallo. State precisely what this does establish and one important thing it does not — and name the provenance caveat a careful analyst keeps in view.

24. Write one sentence an honest odontologist could say on the stand about a positive dental identification, and one sentence that would be an overstatement if said about a bite mark.

Answer key (click to expand) **Multiple choice:** 1-B · 2-B · 3-C · 4-C · 5-B · 6-C · 7-B · 8-B · 9-C · 10-B · 11-B · 12-B · 13-B · 14-B · 15-C · 16-B · 17-C · 18-B **Short answer (model points):** **19.** Dental identification is a *comparison* method: it matches the body's teeth against a documented record of that living person's dental care, so its strength depends entirely on that record existing and being good. A decedent with perfect, fully untreated teeth and *no dentist of record* may be unidentifiable by odontology, because there is nothing documented to compare against — the teeth are intact but the record is absent. **20.** **Rule:** a tooth recorded as present can later be missing (present→missing is biologically possible, so *explainable*, e.g., a later extraction); a tooth recorded as extracted cannot reappear intact (missing→present is impossible, so *unexplainable*). The method leans on this because the *direction* of change is a hard logical constraint: it lets an examiner tell a stale record from a genuine mismatch, preventing a naive reader from misreading later dental work as an exclusion. **21.** Concordance is *shared* by an unknown number of similar mouths, so any number of matches only makes the identity *probable*; a genuine irreconcilable difference, by contrast, can come from only one place — the wrong body — so it *excludes* with near-certainty. This is the chapter's instance of "exclusion over proof": the method's surest voice is the one that says *not this person.* **22.** "Which question is this odontologist answering, and is *that question* one the method can validly answer?" (Identification — yes; individualizing a bite mark in skin — no.) The credential certifies the expert, not the validity of the specific claim. **23.** It *establishes*, on valid grounds, the identity of the decedent — the burned body is Marcus Diallo — and thereby kills the "substituted body / faked death" theory. It does *not* establish how, when, or by whom he died (those are the autopsy's, arson's, and the suspects' questions). **Provenance caveat:** the conclusion rests on the antemortem records being genuinely Diallo's and correctly filed — a chain the investigation must verify and keep in view. **24.** **Honest (identification):** "The antemortem and postmortem dental records exhibit concordant features and no unexplainable discrepancies; in my opinion they are from the same individual." **Overstated (bite mark):** "The defendant's teeth made this mark on the victim's skin, to the exclusion of all other people, to a reasonable degree of dental certainty."