Dental Wear and Molar Pulp Volume Reduction in Macaca fascicularis

Area of Science:

• Paleontology
• Comparative Anatomy
• Dental Anthropology

Background:

• Odontoblasts continuously deposit dentine, leading to a natural decrease in molar pulp cavity volume with age.
• Primate species consuming more abrasive diets exhibit larger molar pulp volumes in unworn teeth.
• It is hypothesized that abrasive diets trigger increased dentine deposition to enhance molar wear resistance and longevity.

Purpose of the Study:

• To investigate whether age or tooth wear is a stronger determinant of molar pulp volume reduction in primates.
• To test the hypothesis that species with more abrasive diets deposit more dentine throughout life.

Main Methods:

• Micro-computed tomography (micro-CT) scans were used to measure molar pulp volume and assess wear in Macaca fascicularis molars.
• Reduced major axis regressions were employed to analyze the relationship between age, wear, and pulp volume.

Main Results:

• Both increasing age and increasing molar wear were significantly correlated with decreased pulp volume.
• Molar wear demonstrated a stronger negative correlation with pulp volume (R² = 0.890) compared to age (R² = 0.546).
• A mixed linear model confirmed significant negative impacts of both age and wear on pulp volume.

Conclusions:

• Tooth wear is a more significant factor than chronological age in reducing molar pulp volume.
• Findings suggest odontoblast activity is responsive to wear, potentially mediated by sensory feedback, and highlight the link between diet and tooth structure.
• The strong correlation between wear and pulp volume reduction has implications for estimating age at death, particularly in paleontological contexts.