Biology subjects

Krueger, K. L.

Publications and source records attributed to Krueger, K. L..

2 recordsLinked to original sources

bioRxiv2025

Tracking molar wear in captive baboons: sex and age effects using a modified Scott scoring system

ObjectivesThis study evaluates molar wear progression in a captive baboon population under controlled dietary and environmental conditions. By comparing the dentin exposure ratio (DER) with a newly developed quadrant-based modification of Scotts dental wear scoring system (Krueger-Scott method), we evaluate how wear patterns vary by age, sex, and occlusal region. Materials and MethodsMandibular second molars (M2) were assessed at two timepoints, during life and postmortem, in 201 captive baboons from the Southwest National Primate Research Center. Krueger-Scott and DER data were collected from 3D intraoral scans processed in MEDIT Link software. The Krueger-Scott scores assigned ordinal scores (1-10) to four equal quadrants of each M2 based on enamel facet development and dentin exposure. Statistical analyses tested relationships between wear progression, quadrant location, sex, and age. ResultsKrueger-Scott scores and DER values increased significantly between timepoints, indicating wear progression. However, Krueger-Scott scores revealed strong functional patterning: buccal and lingual cusps showed high within-group correlations and weaker cross- group correlations. Males showed significantly higher wear than females, despite being younger on average. The relationship between age and wear progression differed by sex. DiscussionThe Krueger-Scott method provided a more anatomically informative and efficient approach to tracking occlusal wear than DER. It captured regional wear variation and functional asymmetries that DER could not detect. Even under controlled conditions, sex-based differences in wear emerged, likely reflecting behavioral, morphological, or enamel structural variation. These findings offer a comparative baseline and demonstrate the utility of quadrant- level scoring for interpreting wear in extant and extinct taxa.

animal behavior and cognition↗

bioRxiv2024

Assessing tooth wear progression in primates: A longitudinal study using intraoral scanning technology

Intraoral scanners are widely used in a clinical setting for orthodontic treatments and tooth restorations, and are also useful for assessing dental wear and pathology progression. In this study, we assess the utility of using an intraoral scanner and associated software for quantifying dental tissue loss in non-human primates. An upper and lower second molar for 31 captive hamadryas baboons (Papio hamadryas) were assessed for dental tissue loss progression over multiple years (n = 62 teeth). The animals are part of the Southwest National Primate Research Center and were all fed the same monkey-chow diet over their lifetimes. Two molds of each dentition were taken at either two- or three-year intervals, and the associated casts scanned using an intraoral scanner (Medit i700). Tissue loss was calculated in WearCompare by superimposition of the two scans followed by subtraction analysis. Four individuals had dental caries, and were assessed separately. The results demonstrate the reliability of these techniques in capturing tissue loss data, evidenced by the alignment consistency between scans, lack of erroneous tissue gain between scans, and uniformity of tissue loss patterns among individuals (e.g., functional cusps showing the highest degree of wear). The average loss per mm{superscript 2} per year for all samples combined was 0.05 mm3 (0.04 mm3 for females and 0.08 mm3 for males). There was no significant difference in wear progression between upper and lower molars. Substantial variation in the amount of tissue loss among individuals was found, despite their uniform diet. These findings foster multiple avenues for future research, including the exploration of wear progression across dental crowns and arcades, correlation between different types of tissue loss (e.g., attrition, erosion, fractures, caries), interplay between tissue loss and microwear/topographic analysis, and the genetic underpinnings of tissue loss variation.

evolutionary biology↗