Description of a communication between the facial and zygomaticotemporal nerves.

Communicating branches between the facial and the trigeminal nerves are known to exist; however, both their frequency and significance are incompletely understood. In our anatomic dissections, we observed a consistent anastomosis between the temporal branch of the facial nerve and the zygomaticotemporal branch of the trigeminal nerve. The facial nerves were dissected in 17 cadaveric half faces. The communicating facial-zygomaticotemporal nerve branches piercing the superficial layer of the deep temporal fascia were identified and followed through the fascial and muscular planes. Fourteen out of 17 dissected cadaveric half faces contained communications between trigeminal and facial nerves. In these specimens, one or two branches from the temporal branch of the facial nerve would penetrate the superficial layer of the deep temporal fascia to join the zygomaticotemporal nerve. These communications were found at an average of 36 mm lateral and 2 mm superior to the lateral canthus. Due to the cadaveric nature of the study it is difficult to ascertain the function of the described communication. Our histochemical analysis suggests that these connections contain myelinated fibers, which could either be proprioceptive or motor fibers.