Strategies for organizing and photographing articulated human teeth

I recently posted a primer outlining the strategies I find particularly useful for handling high volumes of loose human teeth during bioarchaeological analyses. However, the mortuary assemblage I worked with for my dissertation actually contained a mixture of loose teeth and dentition that was still articulated in alveolar sockets. This meant that I needed to develop strategies for dealing with teeth that were loose and teeth that were articulated.

My first day on the job, after organizing the mountain of museum storage cases that arrived for my final necropolis, I threw up my hands in exasperation and considered simply noting “teeth present” or “teeth absent” on my data spreadsheets. However, much as I adore Tom Holt and strive to emulate him in all aspects of my life, I doubt that my advisors would be pleased if I turned in a Holtsian-style dissertation.

Tom Holt author bio

Instead, I came up with a method that consists of six different steps.

High-tech screening equipment that cost $2.50.

High-tech screening equipment that cost $2.50.

1. Hand-screen and sort all of the material from one provenience in order to isolate all of the dentition and all mandibles or maxillae with alveolar sockets. I used this method when conducting what was solely a dental analysis for my final necropolis; however, during my first season of data collection, when I conducted a total bioarchaeological analysis of a series of commingled burials, I also found it to be a useful strategy. Pulling all of the teeth first ensures that you can identify and analyze them in one fell swoop, instead of succumbing to the mind-jarring and arduous process of switching back and forth between teeth and bone fragments. This method is additionally useful because it allows you to compare all of the dentition that excavators collected from a given area, examining teeth to look for mirrored matches, and refitting fragmentary mandibles and maxillae to make your MNI estimates more rigorous. I advise screening for mandibular or maxillary bone without dentition as well; scoring sockets for any signs of resorption can provide you with baseline estimates of alveolar resorption (and hence potential periodontal disease) for your population.

Pronounced alveolar resorption in a Copper Age mandible

2. Separate all of the loose dentition from the articulated dentition. Once you have everything even vaguely related to teeth pulled, separate the loose dentition from teeth articulated in fragments of mandibles and maxillae. I would usually put these two groups on separate trays in order to keep things organized.

3. Examine all mandibular and maxillary fragments to look for possible refits. Once you’ve culled all of the alveolar bone, separate the mandibular and maxillary fragments and side them. After they’re sided, compare all fragments from one side to see if any refit, and once everything on one side is refit, compare it to alveolar bone from the opposite side to look for further refits and/or dental matches. I looked for a number of different cues to signal a match, including the dimensions of the alveolar bone, taphonomic treatment (e.g. weathering, coloration) and the size and wear of the associated dentition. I did not try to match maxillae to corresponding mandibles, because the possibility of false positives was too high for most proveniences. However, if you’re working with lower volumes of material, this might be a feasible strategy if you first sort the elements into groups based on age using the eruption, development and wear of associated dentition.

Excavating a mandible from sediment, summer 2013 (this photo is staged)

Excavating a mandible from sediment, summer 2013 (this photo is staged).

4. Compare the refit and sided articulated dentition to the loose dentition. My strategies for organizing loose dentition are outlined in another post, but after I’d organized both loose dentition and articulated dentition, I compared all of the dentition to look for mirrored pairs and narrow down MNI estimates. The only loose teeth that I tried to refit to mandibles or maxillae were molars. Because molars have variables numbers of roots that demonstrate idiosyncratic curvature, you can almost never securely slot a non-associated molar into an alveolar socket it does not belong to. The same argument cannot be made for the single roots of premolars, canines and incisors; because these teeth almost always have only one root that lacks significant curvature, false positives are a far greater possibility. However, I did attempt to mirror articulated premolars, canines and incisors with the same categories of loose teeth from the opposite side, examining wear and the size and shapes of crowns in order to look for matches.

5. Enter all dentition associated with a single individual into a single spreadsheet row. I found it faster to organize my spreadsheets so that all the dentition associated with an individual mandible or maxilla could be entered in one batch, rather than entering it on a tooth by tooth basis. A spreadsheet is worth a thousand words, so at some point in the near future I plan on posting templates of the dental data collection spreadsheets I developed to demonstrate the methods that I used.

6. Photograph the buccal, lingual and mesial views of articulated denitition. Just as I did for loose teeth, I used a sandbox in order to position and orient the alveolar bone I photographed. Unless there were clearly visible caries on the mesial or distal side of observable teeth, I skipped mesial and distal photographs because the articulation of neighbouring teeth meant that most mesial and distal surfaces were not visible.

Photographing mandiblesInstead, I arranged mandibular and maxillary fragments in groups of about five or six, positioning them so that their buccal view was visible first, and then took photographs of the buccal view, the lingual view and the occlusal view, with the teeth oriented as they would be in anatomical position. This gave me visual documentation of wear, enamel hypoplasias abscesses, supernumerary dentition, and any mesial, buccal and occlusal caries that were present in those views.

As with loose teeth, I arranged elements in ascending order relative to their alphanumeric unique identifier, with the lowest number in the upper left-hand corner and the highest number in the lower right-hand corner. This means that in a given photograph, I can immediately associate the bones pictured with their identifier, a useful strategy if I ever need to go back through my photographs to double-check an identification.

Photographing maxillae

Finally, I always took photographs in the same order. This way, I knew that the lowest photo number in a given folder was the buccal view while the highest photo number was the occlusal view. I also gave each series of mandibular or maxillary photographs its own labelled folder – a necessary step when photographing twenty alveolar fragments at a time.

If any other bioarchaeologists or osteologists have their own strategies for dealing with dental predicaments of this nature, I’d love to hear them. And, if your life is currently plagued with vast numbers of human teeth, my deepest sympathies, but I hope you found this useful.

TGIF everybody!

Image Credits: All osteological images were taken at the Museo de Jaén in summer 2013 and summer 2014. The Tom Holt author bio can be found in his volume Expecting Beowulf (2002), which incidentally does touch upon the field of archaeology.

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One Response to Strategies for organizing and photographing articulated human teeth

  1. Pingback: Bone Broke Year in Review | Bone Broke

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