Relation between the external branch of the superior laryngeal nerve and the superior thyroid artery: a study in 101 nerves.

Objective: This paper aims to propose a protocol with the topographical relations of the ESLN and the superior thyroid artery in order to minimize the number of flaws in the proposals found in the literature.

Methods: the cervical regions of 57 human cadavers from the Forensic Medicine Institute were dissected bilaterally, with photographic identification of the ESLNs and their relation to the superior thyroid artery. These data were used to propose the following classification: Type 1: unidentified ESLN; Type 2: the ESLN crosses the superior thyroid artery 1.