Topography of the ductus parotideus opening in thoroughbred horses

Abstract

The AA. studied the ductus parotideus opening in 117 heads of thoroughbred horses, 69 males and 48 females and related it to the vestibular surface of the upper cheek teeth, or better, to:
1st) the ridge that demarcates the grooves of the vestibular surface of the upper 2nd premolar — 73 pairs (62.4% ± 4.5 — 42 males and 31 females, from 2 to 4 years old).
2nd) the contact line between the 2nd and 3rd upper premolars — 37 pairs (31.6% ± 4.3 — 23 males and 14 females, from 4 to 6 years old).
3rd) the contact line between the 1st and 2nd upper premolars — 5 pairs (4.3% ± 1.9 — 3 males and 2 females, from 3 days to 1 year old).
4th) the ridge that demarcates the grooves of the vestibular surface of the upper 3rd premolar — 2 pairs (1.7% < ± 1 .2 — 1 male and 1 female, from 8 to 13 years old).
The bi-lateral symmetry of the opening of the ductus pnrotideus was always evident.
Sex did not influence the opening of the ductus parotideus.