Effects of aging on the endodontic system, reserve crown, and roots of equine mandibular cheek teeth.

This study investigates the changes that occur with age in the endodontic system, reserve crown, and roots of horse cheek teeth. By examining and comparing teeth from horses of a variety of ages, the research identifies significant morphological changes over time and discusses their potential impact on endodontic treatment in horses.

Research Methods

• The research used 48 right hemi-mandibles from horses aged from 2 to 9 years old. These hemi-mandibles were gathered and studied using a variety of methods, including radiography, x-ray computed tomography, and histologic examinations. These combined methods ensured thoroughness in the identification and comparison of tissue types.
• Computational tomography reconstruction and reformatting were used to capture images of the cheek teeth structure, efficiently helping to understand and analyze their morphological transformations.

Results Summary

• The study found that in younger horses, around the time of eruption, cheek teeth appeared as an exposed crown and a reserve crown with an extensive dilated apex. There was no distinct pulp chamber or roots. The teeth’s endodontic system consisted of 5 or 6 pulp horns (where nerves enter the tooth) that were connected to a wide pulp in the reserve crown, extending to the primordial pulp bulb surrounding the apex.
• However, within 2 years after eruption, the formation of mesial and distal roots (the parts of the tooth embedded in the jaw) and a pulp chamber occurs. This distinct pulp chamber, which communicates with the pulp horns and both root pulp canals, can be identified for around 4 to 5 years from the time of root formation.
• Further change happens 6 to 8 years after eruption, where the endodontic system of the cheek teeth now consists of two unconnected compartments, each consisting of a root canal, pulp chamber, and 2 or 3 pulp horns.

Conclusions and Implications

• The research concluded that age-related morphological changes in equine mandibular cheek teeth are significant and must be taken into consideration when performing endodontic therapy in horses. This suggests that a horse’s age could directly impact the approach to, and success of, endodontic treatments and therapies.