456 Dr. Turner on Variations in the origin of the Long [June 1 8; 



X. Notes on Variations in the origin of the Long Buccal Branch 

 of the Fifth Cranial Nerve/' By Wm. Turner, M.B. (Lond.) , 

 Professor of Anatomy, University of Edinburgh. Communi- 

 cated by Dr. Sharpey. Received June 9, 1868. 



In the; Journal of Anatomy and Physiology, November 1866, I gave a 

 description of a specimen from the dissecting-room in which the long buc- 

 cal nerve, instead of proceeding from the third division of the fifth nerve, 

 arose from the superior maxillary trunk in the spheno-maxillary fossa. 



This transposition of the origin of the nerve from its proper trunk to 

 one which is sensory in function, seemed to me to be a strong additional 

 argument, and from a new point of view, to those which had previously 

 been urged by various writers on physiological and pathological grounds, 

 in favour of the purely sensory nature of this nerve. 



In a subject dissected during the month of March of the present year, 

 variations of an interesting kind in connexion with this nerve were ob- 

 served, which afford additional proof of its sensory nature. 



The occurrence within so short a period of two subjects presenting varia- 

 tions of so important a nature in their bearings on the much disputed ques- 

 tion of the physiology of this nerve, leads me to offer these notes to the Royal 

 Society, in the hope that, if inserted in its Proceedings, the attention of 

 anatomists may be more generally directed to the matter, and lead perhaps 

 to further observations of a similar nature. 



When the superior maxillary trunk was exposed on the left side of the 

 head in the spheno-maxillary fossa, in addition to the orbital and palatine 

 nerves usually arising from it in this locality, a branch of some size arose, 

 which descended behind the posterior surface of the superior maxilla. In 

 ,its course it gave origin to two distinct superior dental nerves, which 

 o entered foramina in the bone for the supply of the upper teeth. The 

 .upper of these dental nerves was joined immediately before entering its 

 foramen by another superior dental branch, arising independently from the 

 superior maxillary trunk. After giving origin to these superior dental 

 nerves, the branch, now considerably diminished in size, passed downwards 

 . to the cheek, where some of its fibres pierced the substance of the bucci- 

 nator muscle at the spot where it is usual for the long buccal nerve to enter 

 it, whilst others formed a distinct anastomosis with branches of the portio 

 dura in the fat over the surface of |^that muscle. No buccal nerve from 

 the inferior maxillary was observed on this side. This arrangement cor- 

 ' responds almost exactly to the specimen above referred to, as described 

 in the Journal of Anatomy and Physiology, and the two are, I believe, the 

 only examples of the kind up to this time recorded. 



On the right side of the same subject a different arrangement was ob- 

 served. From the superior maxillary trunk in the spheno-maxillary fossa, 

 in addition to its proper branches, two slender nerves arose, which passed 

 obKquely downwards and forwards through the mass of fat beneath the ramus 



