PERIPHERAL BRANCHES OF THE FACIAL-NERVE I N THE LOWER FACE - ANATOMY AND CLINICAL CONSEQUENCES

The available descriptions of the innervation of the depressor anguli oris muscle and the peripheral distribution of the terminal branches o f the marginal mandibular branch and buccal branches of the facial ner ve are conflicting. Based upon dissections of 25 head halves we invest igated the courses of the terminal branches of the marginal mandibular and buccal nerves. The marginal mandibular and buccal branches were f ound to form in the area of the mental foramen the mental and buccal p lexus innervating the mimetic muscles by terminal nerve branches in th e cheek area. The buccal plexus supplied the muscles of upper lip, che ek and nose. Furthermore, the depressor anguli oris muscle was also su pplied by the buccal plexus. We also observed connections between marg inal mandibular branch and mental nerve and between buccal branches of the facial nerve and buccal nerve of the trigeminal nerve. In case of injury to the marginal mandibular branch the depressor anguli oris mu scle is not affected. Injury to the nerve branches of the depressor an guli oris muscle can be caused by operations or lesions in the area of the posterior border of this muscle.