[The origin and function of the enamel cup, infundibulum dentis, on the incisors of the horse].

This research article examines the origin and function of the enamel cup, also known as infundibulum dentis, on the incisors of horses. The study finds that these enamel cups evolved as ancient horses adapted their diet from hard to soft leaf food and from mixed nutrition (leaves and grass) to exclusively grass.

Origins of the Enamel Cup

• The research traces the origin of the enamel cups on horse teeth back to the Oligocene and Miocene epochs. These are periods dating from 34 million to 5.3 million years ago, during which ancient horse species had to adapt their diets due to environmental changes.
• This shift in diet required morphological changes in their teeth, resulting in the development of the enamel cups. This evolutionary adaptation was crucial as it facilitated the consumption of softer leaf food and grass.

Function of the Enamel Cup

• The infundibulum dentis, or enamel cup, plays a significant role in the incisors’ structure. The occlusal surface (the part of the tooth that comes into contact with other teeth) continually changes due to erosion that follows the pattern of the enamel crests.
• This continuous reshaping of the incisors throughout the life cycle of an equid (a family of animals that includes horses, donkeys, and zebras) is vital for efficient feeding.

Impact of Infundibulum Dentis on Equid Life Cycle

• The research highlights that this evacuation patterns of occlusal surfaces of the incisor optimises the horse’s grip on food, which directly influences the efficiency of ingestion.
• The improved ingestion capacity is particularly beneficial during the sexual maturity stage, which is the optimal period for their food intake. Therefore, this dental adaptation can be seen as contributing significantly to their survival and reproduction success.