Related Experiment Video
Updated: Aug 7, 2026
06:16
Microhardness Measurements on Tooth and Alveolar Bone in Rodent Oral Disease Models
Published on: April 26, 2024
Modern human molar enamel thickness and enamel-dentine junction shape
T M Smith1, A J Olejniczak, D J Reid
1Human Evolution Department, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany. tsmith@eva.mpg.de <tsmith@eva.mpg.de>
Archives of Oral Biology
|July 4, 2006
Summary
Human molar enamel thickness and shape vary significantly by tooth type, sex, and population. These variations are crucial for accurately comparing modern humans with fossil apes and hominins.
Area of Science:
- Paleoanthropology
- Human Anatomy
- Dental Morphology
Background:
- Understanding variation in human dental morphology is key to interpreting the fossil record.
- Enamel thickness and enamel-dentine junction (EDJ) shape are important traits for distinguishing hominoid taxa.
Purpose of the Study:
- To quantify variation in enamel thickness and EDJ shape in a diverse modern human sample.
- To assess how these variations differ between molar types, sexes, and populations.
Main Methods:
- Histological sections of human molars were analyzed.
- Measurements of enamel cap area, dentine area, EDJ length, and bi-cervical diameter were taken.
- EDJ shape was quantified using digitized landmark coordinates.
Main Results:
- Upper molars exhibited greater enamel thickness than lower molars.
- Enamel thickness increased from M1 to M3, influenced by changes in enamel cap and dentine areas.
- Significant differences in EDJ shape and enamel thickness were observed between sexes and among populations.
Conclusions:
- Molar enamel thickness and EDJ shape display considerable variation within modern humans.
- These factors are critical for the taxonomic classification and comparison of fossil hominoids.
- Human enamel thickness ranges broadly, potentially limiting its sole taxonomic utility for fossil comparisons.
Related Concept Videos
01:15Teeth
The formation of teeth, also known as odontogenesis, is a complex process that begins in utero, around the sixth week of embryonic development. There are three stages to this process: the bud stage, the cap stage, and the bell stage.
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
01:21Tooth Anatomy
The human tooth enables us to eat a variety of foods, speak clearly, and even aid in shaping our faces. Teeth are composed of various elements that work together. Here's a detailed look at the anatomy of a human tooth.
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or grinding food.
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or grinding food.