Two-point time-series of dental wear scores for baboon mandibular second molars
Data files
Nov 18, 2025 version files 75.15 KB
-
DER_measurements.txt
11.86 KB
-
KruegerScottScores.txt
59.43 KB
-
README.md
3.86 KB
Abstract
The pattern and rate of dental wear is often used in paleontology, paleoanthropology, and osteoarchaeology to infer age of the individual, abrasiveness of diet, masticatory function, etc. There are numerous hypotheses as to the relative impact of various parameters on the rate of dental wear in primates. However, these studies are complicated by the fact that most samples of dental wear are derived from wild populations. Here, we investigated the rate of molar wear in a captive colony of baboons (Papio hamadryas) from the Southwest National Primate Research Center (San Antonio, Texas). These animals lived in similar group cages and had access to the same uniform diet of monkey chow. Thereby, many of the potential contributing factors to tooth wear have been held constant. We investigated rate of wear with data from two time-points in the life of each animal. The first time-point was captured during life when the individual was anesthetized, a high-resolution dental mold was taken, and from which a high-resolution plaster cast was made. The second time-point was captured from the skeletonized skull of the individual after death. We made high-resolution oral scans of the plaster casts and the skulls. We characterized the occlusal wear using two different methods. First, we applied a modified wear scoring system that we developed for use on baboon molar morphology. We scored the wear for four quadrants of lower second molars for 202 individuals. The second method is the dentin exposure ratio (DER). With these data, we analyzed the rate of wear, sex, and age-by-sex effects. Our results indicate that males have higher wear scores on average than females, and that males have a higher rate of wear compared to females. We also found that the two buccal cusps had a higher correlation in wear score compared to the lingual cusps, and vice versa. When we consider the information that was gained from the the Krueger-Scott scores compared to DER, the DER measurements took much more time to collect and provided much less information about occlusal molar wear.
https://doi.org/10.5061/dryad.3j9kd51vf
Description of the data and file structure
The data file has eleven columns and 808 rows of data. We collected data from 202 individuals. Each individual has four rows of data, reporting the wear score for each of the four molar quadrants.
File: KruegerScottScores.txt
Description: Each variable is described below.
Variables
- Specimen number (W#): This reports the identification number of the individual baboon that was given when the skull was entered into the collection at Washington University St. Louis.
- Sex: This reports either "male" or "female", and is based on the sex designation by the veterinarians at the Southwest National Primate Research Center (SNPRC).
- Tooth position: Data were collected by molar quadrant. Therefore, each individual animal has four rows of data, one for each molar quadrant. This column indicates one of four quadrants: buccal-mesial, buccal-distal, lingual-mesial, or lingual-distal.
- First Scott Score (mold): This is the modified Scott Score for the specific quadrant at time-point one. More specifically, this is the wear shown on the plaster cast that was made from the mold taken during life. The cells in this column contain numerical whole numbers ranging from 1 to 10.
- Second Scott Score (after death - osteological specimen): This is the modified Scott Score for the specific quadrant at time-point two. More specifically, this is the wear shown on the skull, and thereby represents the wear of the molar quadrant at the time of death. The cells in this column contain numerical whole numbers ranging from 1 to 10.
- Date of Birth: This is the date of birth for the individual based on the SNPRC records. The date is reported as Month/Day/Year.
- Date of mold: This is the date when Leslea Hlusko made the dental mold from the living baboon. The date is reported as Month/Day/Year.
- Date of death: This is the date of death for the individual based on the SNPRC records. The date is reported as Month/Day/Year.
- Age at mold months: This is calculated from the date of birth and the date of mold values. Values are reported in months.
- Age at death months: This is calculated from the date of birth and the date of death. Values are reported in months.
- Months between mold and death: This value reports the number of months between when the mold was made and when the animal died. It was calculated from the Date of mold and the Date of death columns. Values are reported in months.
File: DER_measurements.txt
Variables
- W#: This reports the identification number of the individual baboon that was given when the skull was entered into the skeletal collection.
- Left or Right M2?: This provides which mandibular second molar was used for analysis.
- Death Dentin area: This is the area in mm2 of dentin found on the occlusal surface at death.
- Death Occlusal area: This is the area in mm2 of the total occlusal surface at death.
- SKEL DER: This is the Death Dentin area divided by the Death Occlusal area to provide the dentin exposure ratio (DER) at death.
- SKEL PED: This is the DER at death multiplied by 100 to provide the percent of exposed dentin (PED) at death.
- Cast dentin area: This is the area in mm2 of dentin found on the occlusal surface at casting.
- Cast occlusal area: This is the area in mm2 of the total occlusal surface at casting.
- CAST DER: This is the Cast dentin area divided by the Cast occlusal area to provide the dentin exposure ratio (DER) at casting.
- CAST PED: This is the DER at casting multiplied by 100 to provide the percent of exposed dentin (PED) at casting.
We provide tab-delimited text files that contain the data analyzed for the published study.
For information on the scoring system, see Krueger et al. (2025).
The KruegerScottScore.txt file includes the sex, date-of-birth, date-of-death, date-of-dental-casting, and a qualitative score that reflects the degree of wear on each of the four quadrants of the mandibular second molar of 202 baboons from the captive colony at the Southwest National Primate Research Center (SNPRC). Individual baboons are refered to by W# (an identification number assigned to them when the skulls were incorporated into a collection then-curated at Washington University in St. Louis). The birth and death dates are from the SNPRC. The date of the dental-mold/dental-casting is from the records of Leslea Hlusko, as she took the molds in coordination with the SNPRC.
The scoring system was developed by Kristin Krueger, modifying the method of Scott (1979) to conform to the shape of baboons molars. The degree of wear was scored from 1 to 10, with 1 being the least worn, and 10 being the most worn. All scores were taken from high-resolution surface scans of the plaster casts (time-point-one) and the skulls (time-point-two). Details of the scoring method are reported in Krueger et al. (2025).
The dataset includes ages and the number of months between the two time-points. These values were calculated based on the dates also reported in the dataset. No other data processing has been done.
The DER.txt file includes the same W# for each individual, the anatomic side of the tooth measured, the dentine and occlusal areas at death (measurements from the skeletonized skulls), and the dentin and occlusal areas from the cast made during life ("cast").
Dentin and occlusal areas are reported in mm2.
References:
Krueger, K.L., Towle, I., Matthews, G.J., Álvarez-Fernández, A., Hlusko, L.J. 2025. Tracking molar wear in captive baboons: sex and age effects using a modified Scott scoring system. American Journal of Biological Anthropology 188:e70126. DOI: 10.1002/ajpa.70126
Scott, E. C. 1979. “Dental Wear Scoring Technique.” American Journal of Physical Anthropology 51, no. 2: 213–218. DOI:10.1002/ajpa.1330510208