Morphological characteristics of the facial muscles in wild boar (Sus scrofa)

Abstract

The observations of the study were focused on the facial musculature in wild boar in order to describe and observe their peculiarities. The study was realized by dissection on a head of a wild boar, 1,5-2 years old, in two layers, a superficial and a deep one. There were analyzed the muscles of the mouth, of the nose and of the eye, and the masseter muscle. It was noticed a large cutaneous muscle of the face, especially the ventral part (risorius muscle), that inserts on the commissure of the lips. The main particular aspects were remarked for the muscles of the upper lip and nostrils. In this way it was found that the levator muscle of the upper lip is very developed, occupying the dorsal half of the canine fossa and has a very strong tendon inserted in the dorsal part of the upper lip. The depressor muscle of the upper lip is also developed, but less than the levator one, placed in the ventral part of the canine fossa. Its tendon ramifies before insertion in the ventral part of the upper lip. The canine muscle is also massive, placed dorsally to the depressor muscle of the upper lip, in the ventral half of the canine fossa, being partially covered by the levator muscle of the upper lip. It has a large area of insertion, in the lateral wing of the nostril, by a lot on tendinous branches, the main one being the most dorsally placed. The three muscles from canine fossa are partially covered by the nasolabial levator muscle, which is large oro-aborally, and short dorsoventrally, being thin and having the fibers oblique disposed. The buccal muscle and depressor muscle of the lower lip are short due to the deep commissure of the lips. The buccal muscle is covered dorsally by the zygomatic muscle which is relatively short. The orbicular muscle of the mouth is large and thin. The orbicular muscle of the eye is also thin, as the malar muscle is. For the masseter muscle it was remarked a superficial and a deep layer, reversely disposed. The superficial layer includes many tendinous fibers. The study revealed a large development especially for the muscles that act on the snout, respectively on the upper lip. The aspect is similar with that of domestic pig, but more evident.