Variability of the extracranian branches of the facial nerve (Morphoclinical aspects)

Abstract

Introduction: Numerical and trajectory variability of facial nerve branches is one of the main causes of failed surgery, which determine neurologists and surgeons to perform systematic studies o f variants of branching path and extracranial portion of the facial nerve. Purpose and Objectives: To study the variability of the extracranial facial nerve branches and create morphological path way maps of facial nerve. Material and methods: The variants of branching of the extracranial part of the facial nerve were studied in 12 anatomical parts. Results: The facial nerve variants branching of two primary trunks and cervicofacial temporofacial was predominant in 10 cases out of 12 studied cases, nerve trifurcation was observed only in one case, as evidenced by the case of the nerve branch fan-shaped. The length of the predominant average criteria was in eight cases, followed by three short length and long-term cases in a single case. In five cases the nerve trunk had an upward trajectory, in four cases the trajectory was downward and in three cases there was a horizontal trajectory. In eight cases predominate thick upper torso (temporofacial), in three cases by thick trunks were equal and only in one case the thickness of the lower torso prevailed over the upper torso. The anatomical parts were made on cadaveric material belonging to the same person, in one case we noticed the obvious difference in how right branching nerve is located on the left side of the face, and in the second case differences were not very pronounced. The results show that the distance between the primary trunks between 10 and 70°, the extent of the upper torso (temporofacial) is between 30 and 130°, the extent of the lower torso is between 25 and 70°, the angles of the branches of the upper torso are between 10° and 70°, lower torso angles between branches vary between 20 and 40°. Conclusions: (1) The variability of the extracranial portion of the facial nerve branches falls into a wide range of options. (2) Predominant after branching options -fork in primary trunks and cervicofacial temporofacial after long-stem of medium length, as thick - temporofacial trunk are after Ferry - upward. (3) According to surgical anatomical maps, distances between primary trunks between 10 and 70°, the extent of the upper torso ( temporofacial ) is between 30 and 130°, the extent of the lower torso is between 25 and 70°, the angles of the branches of the upper torso are between 10° and 70°, the angles of the lower trunk branches vary between 20 and 40°.