Communicating root of auriculotemporal nerve with inferior alveolar nerve-looping around accessory meningeal artery

Abstract

Background: The auriculotemporal nerve has been described as having two roots in standard textbooks of anatomy. It lies on the tensor veli palatini muscle while passing backwards behind the lateral pterygoid muscle. It runs behind the temporomandibular joint after passing between the sphenomandibular ligament and the neck of mandible. It ascends over the posterior root of zygoma posterior to superficial temporal vessels. It gives superficial temporal branches and also branches to facial nerve and otic ganglion. The branches to the facial nerve join at the posterior border of masseter. On the face the cutaneous branches supply the tragus, part of the adjoining auricle of the ear and posterior part of temple. Methods: Variations in the origin of the auriculotemporal nerve have been described by many authors in the past and this prompted the study of the auriculotemporal nerve, its origin and course, in 36 specimens (18 cadaveric heads) in bodies that were allotted for dissection purpose to first year medical students in the department of anatomy in P.E.S Medical College, Kuppam. Results: It was seen that the auriculotemporal nerve had two roots of origin and they formed a loop to enclose the middle meningeal artery in all the 35 specimens except in one side of the cadaveric heads. In only one half of a cadaveric head it was found to arise by three roots which formed two nerve loops. The first and second nerve roots joined with each other to form a nerve loop. The third root joined with the inferior alveolar nerve and formed the second nerve loop. The accessory meningeal artery passed through the second nerve loop. The normal presentation of two roots enclosing the middle meningeal artery was not present. Instead the accessory meningeal artery was enclosed between the third root and the inferior alveolar nerve. The middle meningeal artery entered the skull through the foramen spinosum as usual but was not enclosed by the nerve roots. The trunk of the auriculo temporal nerve was seen between the middle meningeal artery and inferior alveolar nerve and the study reports the presence of variant nerve loops encircling the accessory meningeal artery. Conclusion: The variations in the roots of auriculotemporal nerve have been reported in the past and since it is important in the clinical implications of the region especially for the facio-maxillary surgeons and dental surgeons. The incidence of variation has to be documented as this helps in updating the clinical database for surgical procedures and treatment in the region of infratemporal fossa.