The teeth of the horse: evolution and anatomo-morphological and radiographic study of their development in the foetus.

The research aims to track and understand the development and evolution of horse teeth right from their first appearance in the fetus within the ossifying matrix of the mandible and maxilla.

Research Methodology

• The researchers examined the development of teeth in various foetuses at different stages, assessing the teeth’s ontogenetic process.
• They used radiographic examinations of the foetal skull and mandible hemisections, focusing on the latero-medial (LM) and dorsoventral (DV) projections for the skull and mandible.
• Exposure values varied from 35 kV/6 mAs to 58 kV/10 mAs, adjusted as per the size of the skulls and their degree of ossification.

Ossification and Teeth Development Findings

• The first dental germ observed was the P3, at around 138-140 days of pregnancy.
• Post 146 days, P2 and P4 dental germs were visible. The first deciduous incisor tooth (I1) dental germ appeared around 160-168 days of pregnancy.
• Further, the research found that at 180-188 days of pregnancy, the germ of the second incisor (I2) became detectable. By about 224 days, the germ of the third incisor (I3) could also be observed.
• The first molar tooth germ in the mandible (M1) appeared around the 275th day. The maxillary M1 at this stage, not visible radiographically, was indicated by a jelly-like amorphous body within its alveolar cavity.

Conclusion

• The research offered in-depth insights into the evolution and development of teeth in the horse fetus.
• By using radiographic examinations, the researchers were able to track and study the appearance and growth of different types of teeth in the horse fetus.
• The variety in exposure values allowed researchers to adapt the procedure to the specifics of each fetus, contributing to the reliability of the findings.