Age estimation of Arabian mares by incisors morphometry and dentition changes

Accurate estimation of a horse's age based on the condition of the tooth status is necessary as a scientific and artistic technique, which has not been performed so far in pure Arabian horses of Khuzestan (southern west of Iran). This study aimed to investigate the age-dependent changes in the morphology and morphometry of the incisors in Arabian mares of Khuzestan to estimate age and to compare the estimated dental age and actual age. In this study, 78 Arabian mares of Khuzestan were examined in several equestrian clubs. Then, images were taken with a digital camera from the vestibular and occlusal surfaces of the lower incisors. Parameters of deciduous and permanent teeth eruption and their number, occlusal surface changes in the lower incisors including appearance and disappearance of the cup, enamel spot, dental star and appearance, and changes of Galvayne's groove in the upper corner incisor were investigated. Comparison of the clinical crown length of incisors in each group showed that first, second and third incisors (I_1, I_2, and I₃) had the maximum to minimum crown length, respectively. The correlation between actual age and clinical crown length was strong in I₁ (r = 0.73, p ≤ 0.001), I₂ (r = 0.8, p ≤ 0.001), and I₃ (r = 0.81, p ≤ 0.001) in the Arabian mares of Khuzestan. The correlation of estimated dental age with actual age in the Arabian mares of Khuzestan was very strong (r = 0.992, p ≤ 0.001). Therefore, the dental age estimation in the Arabian mares of Khuzestan appears to be very close to the actual age of the animal.