Variation in enamel prism size in primate molars

Area of Science:

• Paleontology
• Comparative Anatomy
• Dental Biology

Background:

• Enamel prism diameter variation is crucial for understanding tooth structure and function.
• Primate molar enamel exhibits complex structural organization.
• The relationship between enamel prism size and enamel volume from the enamel-dentine junction (EDJ) to the outer-enamel surface (OES) requires further investigation.

Purpose of the Study:

• To investigate if larger enamel prism diameters accommodate greater enamel volume in primate molars.
• To determine how enamel prism size relates to enamel thickness and crown location.
• To analyze enamel prism diameter variation across different positions within the enamel layer.

Main Methods:

• Examined enamel prism diameter variation in lower molars from 14 catarrhine species and one platyrrhine.
• Measured prism diameter and enamel thickness in four locations: lingual lateral, lingual cuspal, buccal cuspal, and buccal lateral.
• Collected ten prism diameter readings at inner (near EDJ), outer (near OES), and middle enamel for each location.

Main Results:

• Mean enamel prism diameters were consistent across species (4.06–5.81 µm).
• Prism diameter increased from the EDJ towards the OES, indicating adaptation to increasing enamel volume.
• Average prism diameter did not correlate with enamel thickness; cuspal positions showed smaller prism diameters at the EDJ but larger ones at the OES compared to lateral positions.

Conclusions:

• Consistent average enamel prism diameters were observed across various lower primate molar crown locations.
• The observed pattern of prism diameter increase from EDJ to OES suggests a role in mechanical integrity and functional optimization of primate enamel.