Dimensions of 65 extracted equine first premolar (Wolf) teeth

Reasons for performing study:

The maxillary first premolar (wolf tooth) is present in a significant proportion (13–40%) of horses and is frequently extracted. The size of these teeth has been reported to vary but the authors are not aware of published descriptions of the dimensions of these teeth.

Objectives:

To measure the dimensions of a sample of equine first premolar teeth and to seek correlations between dimensions of the crown and the root.

Study design:

A retrospective descriptive study.

Methods:

Calipers were used to measure total length, root length, crown height, and crown width of 65 first premolar teeth extracted in their entirety from 2 populations of horses (UK population: n = 30, USA population: n = 35). Most of the variables were not normally distributed so nonparametric statistics (Spearman correlation coefficients) were used to describe tooth size and seek correlations between different measurements.

Results:

Dimensions expressed as median (range) were total length: 21 (12–34) mm; root length: 13.2 (0–19.6) mm; crown height 7 (2–20) mm; and crown width 7 (2.6–16) mm. Root length was longer than crown height in 61/65 teeth. Total length was poorly correlated with crown height (r = 0.443) but had a good correlation with root length (r = 0.799). Crown height and crown width were poorly correlated with root length (r = -0.093 and r = 0.463), respectively.

Conclusions:

The dimensions of 65 first premolar teeth indicate that the root is usually longer than the crown but that the dimensions of the clinical crown of the tooth do not provide a good estimate of the length of the root