The communication between the auriculotemporal and the facial nerves,
i.e. the communicating auriculotemporal nerves (CATN), was studied in
55 facial sides from Thai cadavers. CATN only joined the temporofacial
(upper) division of the facial nerve. CATN patterns were classified a
s follows: (1) the facial nerve was joined by 1 CATN (20.7%), (2) by 2
separate CATN branches (60.4%), (3) by 3 separate CATNs (15.1%); (4)
several CATNs ran parallel to the zygomatic and buccal nerves to the m
uscles of facial expression (3.8%). The 4 types of CATN pattern showed
further variations according to the site of union with the facial ner
ve. The superficial temporal artery was crossed by CATN branches anter
iorly in 47.1%, posteriorly in 18.9%, and anteriorly and posteriorly i
n 34.0% of the cases. The facial nerve branches that were joined by CA
TNs were observed to supply the upper muscles of facial expression, i.
e. frontalis, orbicularis oculi and zygomaticus major. Some offshoots
from CATNs were seen to innervate orbicularis oculi. On the basis of o
ur results we suggest that CATNs may convey proprioceptive impulses fr
om orbicularis oculi.