Anatomical reasons for problems after neurectomy for blepharospasm: a study in cadavers.

The purpose of this study is to clarify the mechanisms of the problems that develop after neurectomy for blepharospasm. The left facial nerves in 10 Japanese cadavers were dissected under a surgical microscope. The temporal, zygomatic, and buccal branches innervated to the orbicularis oculi muscle. These three groups formed a well-communicating plexus posterior to the orbicularis. The most inferior buccal branch curved in the deep layer in the lower part of the cheek. In the cheek, both the buccal and the temporal branches had ramifications of other facial muscles. The information given in previous anatomical textbooks did not specifically define the denervation of the orbicularis. When neurectomy was done in the past, the inferior buccal branch may have been kept intact, or other facial muscles as well as the orbicularis may have been denervated which caused the blepharospasm to recur and complications to develop after neurectomy.