DEMIRJIAN'S METHOD

One of the most widely used methods of forensic age estimation via dentition was derived in 1973 by Demirjian, Goldstein, and Tanner.^[1] Commonly referred to as "Demirjian's Technique," the changes from initial calcium deposition to complete apex are divided into eight observable stages. Each stage is further characterized by up to three additional qualifying criteria (a,b,c). If only criterion (a) is listed, then it must be met. If (a) and (b) are listed, then at least (a) must be satisfied. If (a), (b), and (c) are listed, then both (a) and (b) must be met. Additionally, "at each stage . . . the criteria for the previous stage must be satisfied" ^[ibid]. The technique is applied to 7 observed teeth, with the individual "score" from each tooth being added. The resulting sum is then referenced on a corresponding conversion chart with ages ranging from 3 to 17 years, in increments of one-tenth. 

Though the Demirjian method worked well with the original French Canadian subject sample, more recent studies have questioned its effectiveness when applied to sample groups of varied descent. A 2007 study by Tunc and Koyuturk revealed that the technique was less accurate with regard to sampled Turkish children, who   displayed more advanced dental maturity.^[2] 

A 2001 article using Belgian children as the sample group confirmed popular findings that the Demirjian method has a tendency to result in over-estimation of age, but employed new adaptations to the scoring system to achieve an increase in accuracy.^[3] 

The Demirjian technique remains a well-regarded forensic tool for determining age in sub-adults. As with all estimation methods, there is a discernible margin of error, but overall the technique still provides advantages over other dentition methods, especially those based on tooth eruption, which can be highly influenced by health and environmental factors. It should be remembered that in practical application, a synthesis of various age-estimation methods generally yields the best overall results.    

REFERENCES:

1. Demirjian, A., et al. A New System of Dental Age Assessment. Human Biology 45(2): 211. 1973.

    http://www.bristol.ac.uk/cmm/team/hg/full-publications/1973/dental-age-assessment.pdf

2. Tunc, E.S.; Koyuturk, A.E. Dental age assessment using Demirjian's method on northern Turkish
    children. Forensic Science International. 175(1): 23-26. 2008.
   http://www.mendeley.com/research/dental-age-assessment-using-demirjians-method-on-northern-turkish-
   children/

3. Willems G., et al. Dental Age Estimation in Belgian Children: Demirjian’s Technique Revisited.
  Journal of Forensic Science 46(4): 893-895. 2001.
  http://www.kuleuven.be/fortand/MFO/articles/01_JFS_Willems_demirjian.pdf 

HAITI

Haiti, with all of its misfortune -- the atrocious sanitary conditions, profound socioeconomic disparity, and recent natural disasters -- serves as an ideal case study for epidemiologists. The U.N.'s ongoing role there provides an example of how organizational interaction can severely affect the health of a population, for better or worse.   

Global Failures on a Haitian Epidemic

Infectious Diseases of Haiti (E-Book)


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SOME PITHY TITLE ALLUDING TO WINDS OF CHANGE, BLA BLA BLA

I haven't been posting as much as I would like, but some exciting developments are underway. I'm currently finishing my last semester as an Anthropology/Linguistics undergrad, and have decided to forego law school to pursue an MPH in Epidemiology. Of course, this rather recent decision means my plans have been eviscerated. Instead of the LSAT, I need to prepare (rather tardily) for the GRE, and I'm scrambling to put my admissions material together in time to meet application deadlines. All this on top of composing my senior project on Native land rights in the Americas. Still, I haven't been this excited about the future for years, and I'm standing firmly behind my gut feeling on this decision. Though I'm versed in some rudimentary science  and statistics through formal coursework and personal study, I've got a long path ahead of me. As I immerse myself in this academic pursuit, expect the postings to reflect continued exploration of subjects like biostatistics, public health concerns, and infectious diseases, in addition to the topics already covered. I'm not sure where this new direction will spit me out, but I'm certain it will be one hell of an interesting ride!

NEW HUMAN SPECIES?

A new PLoS ONE journal article studies recently-discovered humanoid remains which may be an evolutionary offshoot of Homo sapiens. The skeletons, discovered in caverns in the South-west of China, feature large jaws  (absent chin) and molars, eminent brow ridges, robust bone structure, and flat faces. Caches of fossilized remains from giant prehistoric deer suggest that venison comprised a significant portion of these early humans' diet. The big question now is one of taxonomy: will the "red deer cave people" be classified as a phenotypic anomaly, or a new human species? 

Read the full journal article here:
Human Remains from the Pleistocene-Holocene Transition of Southwest China Suggest a Complex Evolutionary History for East Asians

Related secondary sources:
National Geographic
Live Science


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MUMMIES OF GUANAJUATO

The Museo de las Momias in Guanajuato, Mexico, features a 56-body collection of incredibly well-preserved mummies. Most of the mummies date to around 1833, when they were "accidentally" interred during an outbreak of disease, most likely cholera. The collection has captivated artists and writers, including Werner Herzog and Ray Bradbury. The latter wrote of his visit, "The experience so wounded and terrified me, I could hardly wait to flee Mexico. I had nightmares about dying and having to remain in the halls of the dead with those propped and wired bodies. In order to purge my terror, instantly, I wrote 'The Next in Line.' One of the few times that an experience yielded results almost on the spot."

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