The Peridental Structures of Equine Cheek Teeth: An Age-Dependent Anatomical Study of Maxilla and Mandible.

Plain Language Overview

• This study examined the anatomical structures surrounding horse cheek teeth and how these structures change with age, especially focusing on differences between the upper jaw (maxilla) and lower jaw (mandible).
• Findings helped explain why younger horses, particularly in the lower jaw, are more prone to complications such as bone sequestration after tooth extraction.

Introduction and Background

• Sequestration is a common complication after extracting cheek teeth in horses, involving bone tissue death and delayed healing.
• This problem is more frequent in the mandible (lower jaw) and in younger horses.
• It is hypothesized that trauma to the peridental (around the tooth) structures during extraction impairs healing, but detailed anatomical knowledge of these regions had been limited.
• The study aimed to fill this knowledge gap by analyzing peridental anatomy in relation to age and jaw location.

Study Design and Methods

• Subjects: Six cadaver horse heads were used, representing three different age groups.
• Teeth Examined: Cheek teeth numbered 07 to 09 from both the maxilla (upper jaw) and mandible (lower jaw).
• Preparation: The peridental regions were sectioned horizontally at intervals of about 10 mm along the tooth rows.
• Data Collection: Each section was photographed.
• Quantification: Within a 1 mm zone around the peridental gap (space surrounding the tooth root), the following adjacent structures were measured:
  • Compact bone (dense cortical bone)
  • Spongy bone (trabecular or cancellous bone)
  • Maxillary sinus (upper jaw air cavity)
  • Nasal cavity (in upper jaw only)

Key Anatomical Findings

• Maxillary teeth (Upper jaw):
  • About 50% of the peridental gap area consisted of compact bone consistently throughout.
• Mandibular teeth (Lower jaw):
  • Compact bone made up a greater percentage (around 60.3%) near the occlusal (biting) surface.
  • This proportion decreased toward the apex (root tip), down to roughly 23.7%.
• Age-related trends:
  • Older horses showed generally increased amounts of compact bone surrounding the teeth.

Interpretation and Clinical Relevance

• The higher proportion of compact bone in the mandible suggests that after extraction, there is less blood supply or bleeding into the alveolus (tooth socket).
• Reduced bleeding can impair the transport of cells and nutrients critical for wound healing.
• This lack of bleeding and thick compact bone may also reduce the bone’s ability to resorb dead fragments that can accumulate, increasing the risk of sequestration.
• The age-dependent increase in compact bone may suggest older horses have comparatively better structural support, possibly influencing healing dynamics.
• Understanding these anatomical differences aids in explaining why sequestration is more common in younger horses and particularly within the mandible.
• This knowledge can impact clinical strategies for tooth extraction and postoperative care to reduce complications.

Conclusion

• This study provides detailed, novel anatomical characterization of the peridental region in equine cheek teeth, highlighting differences based on jaw location and age.
• The findings elucidate structural reasons behind clinically observed extraction complications.
• Future approaches in equine dentistry may benefit from considering these anatomical variations to improve healing outcomes.