Age estimation using the ratio of dental pulp to tooth volume by CT scan in dogs.

Importance: Accurate age estimations in dogs are essential for various veterinary and clinical applications. Traditional methods based on dental appearance are error-prone because of external influences, necessitating the development of more precise methodologies.

Objective: This study examined the association between chronological age and pulp to tooth (P/T) volume ratio in dogs using computed tomography (CT) of the right maxillary canine and right maxillary fourth premolar (PM4) teeth.

Methods: Ninety-five canine skulls, aged five to 216 months, were examined using a two-slice CT scan machine. Volumetric analyses of the right maxillary canine and PM4 were performed. Statistical analysis, including Spearman's correlation and regression analysis, was conducted to assess the relationship between age and the P/T volume ratio.

Results: This study included 60 male and 35 female dogs, with no significant age difference between genders (p = 0.655). A strong negative correlation was observed between age and the P/T volume ratio for the right maxillary canine (r = 0.88, p < 0.001) and PM4 (r = 0.77, p < 0.001) teeth. Logarithmic regression models provided a better fit for age prediction (R² = 0.78 for the right maxillary canine, R² = 0.67 for PM4) compared to linear models.

Conclusions and relevance: CT-based volumetric analysis of the P/T ratio in the right maxillary canine and PM4 teeth offers a precise, non-invasive method for estimating the age of dogs. This technique can improve the accuracy of age estimations, particularly in forensic and clinical settings, providing valuable insights for veterinarians and researchers.