Arborization of the inferior laryngeal nerve and internal nerve on the posterior surface of the larynx.

The morphological patterns of the inferior laryngeal nerve and internal laryngeal nerve display complex arborizations. This paper attempts to identify and clarify these patterns. Dissections were performed on 105 adult Japanese cadavers, and observations were made on 201 sides. Results showed that the communications between the inferior laryngeal nerve (ILN) and internal laryngeal nerve (ITLN) could be classified into two types and three subtypes. Also, the ITLN displayed three characteristic patterns at the arytenoid cartilage. These communications produce complex arborizations of the ILN as it enters the larynx. This may explain the variety of potential clinical symptoms observed after thyroid surgery or neck dissections.