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Home / Equine Research Bank / Animals (Basel) / Odontoblasts in Equine Hypsodont Teeth-How They Cope with Pe...
Animals : an open access journal from MDPI2026; 16(2); 341; doi: 10.3390/ani16020341

Odontoblasts in Equine Hypsodont Teeth-How They Cope with Permanent Occlusal Wear.

Abstract: Horses' hypsodont (high-crowned) teeth face permanent dental wear. This is compensated for by a continuous eruption, which requires a high adaptability of odontoblasts; otherwise, the dental pulp would be exposed. Here, we report on how equine odontoblasts respond to the challenge of maintaining a high production rate of dentin. We analyzed CD90, a marker of odontoblastic differentiation, and nestin, a marker of mature odontoblasts, in equine pulpal tissue via immunofluorescence. For comparison, we examined the hypselodont (ever-growing) incisors and brachydont (short-crowned) molars of rats. Immunofluorescence and Western blot analysis of pulpal tissue revealed a higher content of CD90-positive cells in hypsodont equine teeth than in brachydont and hypselodont rat teeth. The odontoblastic layer of hypsodont teeth was positive for CD90 (marker for differentiating odontoblasts), which was not the case for brachydont and hypselodont rat teeth. Most samples of hypsodont teeth were negative for nestin, whereas in hypselodont and brachydont teeth, odontoblasts were positive for nestin (marker for mature odontoblasts). Our findings suggest that there is a constant replacement of odontoblasts in the equine dentition, enabling a continuous high production rate of dentin. These results contradict the idea of lifelong vital, postmitotic and productive odontoblasts.
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Publication Date: 2026-01-22 PubMed ID: 41594529PubMed Central: PMC12838237DOI: 10.3390/ani16020341Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

Overview

  • This research investigates how odontoblast cells in horse teeth, which endure constant wear, maintain their ability to produce dentin continuously.
  • The study compares equine hypsodont (high-crowned) teeth with rat hypselodont (ever-growing) and brachydont (short-crowned) teeth to understand differences in odontoblast activity and differentiation.

Background and Purpose

  • Horses have hypsodont teeth that experience permanent occlusal wear due to grinding during chewing.
  • To counteract this wear, horse teeth continuously erupt, requiring sustained dentin production from odontoblasts to prevent pulp exposure.
  • Odontoblasts are specialized cells responsible for dentin formation; their lifelong activity and adaptability are crucial for maintaining tooth integrity in horses.
  • The research aims to understand how equine odontoblasts cope with the continuous demand for dentin, focusing on cell differentiation and maturity markers.

Methodology

  • Researchers analyzed equine dental pulp tissue using immunofluorescence to detect two key markers:
    • CD90: a marker indicating differentiating odontoblasts.
    • Nestin: a marker associated with mature odontoblasts.
  • For comparison, the study included rat teeth:
    • Hypselodont incisors: teeth that grow continuously.
    • Brachydont molars: teeth with limited growth, similar to human teeth.
  • Immunofluorescence and Western blot analyses were conducted to evaluate the presence and levels of CD90 and nestin in the samples.

Key Findings

  • Equine hypsodont teeth exhibited a significantly higher number of CD90-positive cells compared to rat brachydont and hypselodont teeth, indicating a greater population of differentiating odontoblasts.
  • In the equine samples, the odontoblastic layer stained positively for CD90, suggesting active continuous differentiation of odontoblasts to sustain dentin production.
  • Conversely, the brachydont and hypselodont rat teeth did not show CD90 positivity in the odontoblastic layer, suggesting less reliance on differentiation for sustained dentin production.
  • Most equine hypsodont teeth samples were negative for nestin, implying fewer mature odontoblasts, while rat teeth showed nestin positivity, indicating mature odontoblast populations.

Interpretation and Implications

  • The presence of many CD90-positive cells and fewer nestin-positive cells in horse teeth suggests a mechanism where odontoblasts are continually replaced rather than remaining as long-lived, mature cells.
  • This continuous replacement allows the horse teeth to maintain a high production rate of dentin necessary for coping with permanent occlusal wear from chewing.
  • The findings challenge the previously held notion that odontoblasts are lifelong, non-dividing (postmitotic), and maintain dentin production without replacement.
  • Understanding this process provides insight into equine dental biology and may influence veterinary dental treatments or inform biomimetic dental repair strategies.

Conclusion

  • Equine hypsodont teeth adapt to continuous wear through ongoing odontoblast differentiation and replacement, ensuring persistent dentin formation.
  • This study highlights fundamental differences between species and tooth types in odontoblast dynamics and suggests a paradigm shift in how we view odontoblast longevity and function in high-wear dental systems like those of horses.

Cite This Article

APA
Heilen LB, Roßgardt J, Dern-Wieloch J, Vogelsberg J, Staszyk C. (2026). Odontoblasts in Equine Hypsodont Teeth-How They Cope with Permanent Occlusal Wear. Animals (Basel), 16(2), 341. https://doi.org/10.3390/ani16020341

Publication

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 16
Issue: 2
PII: 341

Researcher Affiliations

Heilen, Laura Beate
  • Institute of Veterinary-Anatomy, -Histology and -Embryology, Faculty of Veterinary Medicine, Justus-Liebig-University, 35392 Giessen, Germany.
Roßgardt, Jessica
  • Institute of Veterinary-Anatomy, -Histology and -Embryology, Faculty of Veterinary Medicine, Justus-Liebig-University, 35392 Giessen, Germany.
Dern-Wieloch, Jutta
  • Institute of Veterinary-Anatomy, -Histology and -Embryology, Faculty of Veterinary Medicine, Justus-Liebig-University, 35392 Giessen, Germany.
Vogelsberg, Jörg
  • Institute of Veterinary-Anatomy, -Histology and -Embryology, Faculty of Veterinary Medicine, Justus-Liebig-University, 35392 Giessen, Germany.
Staszyk, Carsten
  • Institute of Veterinary-Anatomy, -Histology and -Embryology, Faculty of Veterinary Medicine, Justus-Liebig-University, 35392 Giessen, Germany.

Conflict of Interest Statement

The authors declare no conflicts of interest.

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