Anatomical studies of maxillary cheek teeth infundibula in clinically normal horses.
Authors: Fitzgibbon C M, Du Toit N, Dixon P M
Journal: Equine veterinary journal
Summary
# Editorial Summary: Maxillary Cheek Teeth Infundibular Anatomy in Clinically Normal Horses Infundibular disease represents a significant clinical challenge in equine dentistry, yet understanding of normal anatomical variation in these structures has been limited. Fitzgibbon and colleagues examined longitudinal sections of cheek teeth extracted post mortem from 33 clinically sound horses (aged 3–30 years), measuring infundibular dimensions, cemental integrity, and microscopic characteristics across all maxillary cheek tooth positions. The most striking finding was the dramatic age-related reduction in infundibular length—from up to 89 mm in recently erupted teeth to just 2 mm in older horses—with infundibular surface area proportionally declining throughout life. Beyond this expected attrition pattern, the study revealed that cemental pathology was remarkably prevalent: only 11.7% of infundibula contained entirely normal cementum, whilst 88.3% exhibited some form of variation or defect, including complete cemental caries (8.2%), hypoplastic areas (22.6%), central defects, and localised occlusal caries (57.5% combined). The rostral maxillary positions (Triadan 06 and 09) were particularly predisposed to these changes and had notably shorter crown heights. For equine practitioners, these findings establish that cemental abnormalities in clinically normal horses are the norm rather than the exception, suggesting that localised defects—particularly hypoplastic lesions—may act as initiating factors for infundibular caries rather than representing secondary disease. This anatomical baseline should inform more targeted diagnostic and therapeutic approaches to infundibular pathology, potentially moving away from treating all variations as pathological.
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Practical Takeaways
- •Cemental abnormalities in infundibula are the norm rather than the exception in clinically normal horses—88% show some form of cemental variation or pathology
- •Tooth position matters: positions 06 and 09 are at higher risk due to shorter infundibula and increased caries susceptibility, particularly 09; these require closer monitoring
- •Cemental hypoplasia appears to be a significant predisposing factor for infundibular caries, so teeth showing this change warrant preventive intervention or closer surveillance to prevent clinical disease
Key Findings
- •Infundibular length decreases progressively with age from up to 89 mm after eruption to 2 mm in older horses
- •Only 11.7% of infundibula were filled completely with normal cementum; 88.3% showed various cemental abnormalities
- •8.2% of infundibula had complete cemental caries, particularly at the 09 tooth position
- •Triadan 06 and 09 positions had significantly shorter cheek teeth and infundibula than other positions, with 22.6% showing cemental hypoplasia that may predispose to caries development