Proximal communication between the glossopharyngeal and facial nerves

The facial nerve branch termed Ramus communicans cum nervo glossopharyngeo in the current Nomina anatomica was investigated in 245 Japanese, especially as regards the frequency and pertinence as an approved definition. The communication was found in only 18.8%. It runs, if present, either medially, laterally or through the digastric posterior muscle. Teasing examination reveals that it always originates from the ninth nerve instead of the seventh and that it is destined to the back of the pinna. Its terminal bundle leaves the seventh nerve somewhat distally than the posterior auricular nerve in many examples, but the communication is likely to represent the auricular branch of the ninth nerve. As an offshoot of the seventh nerve, it is ill-defined, and should be affiliated to the ninth nerve in the Nomina anatomica. If it pierces the digastric muscle, half examples certainly give additional innervation to this muscle, but the fundamental disposition of the communication itself is not affected.