Intra- and Interexaminer Measurement Variability Analysis of an Orthodontic Gauge Device to Determine Incisor Occlusal Surface Angles in the Horse
Authors: S. Kau, Katharina S. Motter, Viktoria J. Moser, J. R. Kunz, Matteo Pellachin, Bettina Hartl
Journal: Veterinary Sciences
Summary
# Editorial Summary Incisor malocclusion affects many horses, yet objective clinical assessment methods for occlusal surface angles remain largely unvalidated—a significant gap when determining treatment need and tracking outcomes. Researchers evaluated the reliability of the MaPHorse orthodontic gauge device by having five examiners (varying in experience) perform repeated sagittal and transversal angle measurements on six cadaver heads over two days, generating 16 measurements per examiner per head. Sagittal angle measurements demonstrated excellent reproducibility, with low intraexaminer variability (standard deviation 0.58°) and minimal interexaminer differences (maximum 0.51° ± 0.35°), whilst transversal measurements showed good intraexaminer consistency (0.69°) but greater interexaminer spread, suggesting procedural standardisation would strengthen transversal assessment. Notably, measurement accuracy plateaued rapidly—within 24–96 repetitions—indicating that both experienced and inexperienced practitioners could achieve consistent results with brief familiarisation. For equine dental professionals, this validation of a standardised measuring device offers a practical tool for objectively documenting incisor occlusal angles, establishing population-level normative data, and objectively evaluating treatment response to rasping and orthodontic interventions.
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Practical Takeaways
- •This validated orthodontic gauge device can reliably measure incisor occlusal surface angles in clinical practice, particularly for sagittal angles, enabling objective assessment of treatment needs and monitoring of outcomes over time
- •Both experienced and inexperienced practitioners can achieve consistent measurements with this device after minimal repetition (24-96 measurements), making it practical for routine dental examinations
- •Sagittal angle measurements are more reliable than transversal measurements with the current landmarks; practitioners should prioritize sagittal assessment or await refinement of transversal measurement technique
Key Findings
- •Sagittal incisor occlusal surface angle measurements showed low intraexaminer variability (SD 0.58°) and low interexaminer variability (max 0.51° ± 0.35° difference)
- •Transversal angle measures had comparable mean interexaminer differences but 2.2-fold higher interquartile range spread than sagittal measures
- •Measurement performance did not systematically differ between experienced and inexperienced examiners
- •The orthodontic gauge device (MaPHorse1) demonstrated high reproducibility for sagittal angle assessment with clinical applicability