Dental Polish Analysis

Dental polish analysis is used in determining the seasonality and nature of occupations of archaeological sites. This involves assessing tooth eruption and wear stages, and dental polish analysis. Atlatl offers these components individually or as complementary analyses.

Dental polish analysis analyzes microscopic features on bison teeth enamel including reflectivity, surface texture, and surface features. These characteristics can be correlated to seasonal categorizations based upon the moisture and exogenous grit content of grasses consumed by the animals immediately prior to death, both factors which fluctuate seasonally in a predictable pattern. Dental polish is an indicator of seasonality linked only to environmental conditions and not variations in individual growth and is, therefore, more reliable.

Tooth eruption and wear is quick and efficient for analyzing seasonality based on regular patterns in tooth eruption, growth, and wear in bison. The stage of wear on each tooth in each mandible is measured; the sample is then assigned a seasonality as narrow as one month. This method is less reliable than dental polish as it is based on individual growth patterns which can exhibit variation. However, it provides direct information regarding herd composition by offering a season at death and the age of the individual being analyzed, something not possible using dental polish. Combining both dental polish and tooth eruption and wear stages has the potential to narrow seasonality assessments for any given sample, providing a more refined and accurate seasonality than by using either method alone.

The information obtained can provide insight about archaeological site seasonality and herd composition. This can then be used to make broader inferences regarding the recurrent use of the archaeological sites, the nature and intensity of occupation at these sites, and prehistoric hunting practices.

Tooth Eruption and Wear Methods (TEWS):

TEWS analysis involves the use of mandibles and identifiable lower teeth only. This technique is combined with the analysis of exostyle wear and metaconid height measurements to provide a more reliable assessment of seasonality based on tooth wear.

For each sample, each cusp (protocone, metacone, entocone, hypocone [all molars], and hypoconulid from the first, second, and third molar is assessed to determine if it exhibits light (<1 mm) or great wear (>1 mm), if any. These patterns are compared to diagrams presented by Brumley (1990) and a TEWS age assigned. This method is particularly useful for assessing the age and seasonality of younger individuals.

Tooth exostyle wear is also considered by observing the degree of wear on each molar present in the mandible. These are then assigned an approximate age.

Finally, the metaconid height measurement of the first molar is determined from the base of the enamel to the highest point of the metacone. These measurements are compared with mandibles from the Glenrock and Casper sites to equate these with an age estimation. These references are useful for comparison as metaconid height averages which correlate with specific age groups are provided in both contexts.

Dental Polish Methods:

Two cusps from each tooth are analysed for polish, the metacone and entocone whenever possible. Polish is observed using an inverted microscope with reflected light at 400X magnification. Descriptions combine observations from both cusps.

Descriptions of polish include reflectivity and texture of the polish on each tooth, and the frequency and nature of striations, pits, and any other features present. Reflectivity is the intensity by which the surface reflects light (bright versus dull), while surface texture refers to the smoothness/roughness of the surface. The frequency of both striations (coarseness and length) and pits (size) are noted. These descriptions are correlated to the moisture and grit content of the grass consumed prior to death based on the signatures which most closely match the categories outlined by Ewald (2018).

Ewald (2018) demonstrated differences in bison dental polish correlate to differences in moisture and exogenous grit content of grasses consumed by them, factors which vary seasonally in a predictable pattern on the northern Plains.


Sample ProcessingCost Per Sample (CAD)
Tooth Eruption & Wear (Includes cleaning, descriptions, identification, eruption & wear analysis)$75
Dental Polish Analysis (Includes cleaning, descriptions, identification, dental polish analysis & photographs)$125
Analysis & ReportingCosts Per Project (CAD)
Report Writing – entire assemblage$1000 – $2000
Lab Supplies$25 (1 – 20 samples) $50 (21 – 50 samples)
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