RESUMEN
BACKGROUND AND OBJECTIVES: Classical concept of the laryngeal neuroanatomy has been questioned by some authors. Double innervation of some intrinsic laryngeal muscles has been suggested but controversy still exists. This study investigates the possibility of double innervation of thyroarytenoid and interarytenoid muscle and also the proportion of motor component in the external and internal branch of the superior laryngeal nerve. MATERIALS AND METHODS: Horse radish peroxidase (HRP) retrograde labeling in dogs, and choline acetyltransferase (ChAT) immunohistochemistry in feline and human laryngeal nerves were used. RESULTS: Evidences suggesting the existence of double innervation in thyroarytenoid and interarytenoid muscle and the existence of sensory component in external branch and motor component in internal branch of the superior laryngeal nerve have been observed. CONCLUSION: This new concept of the laryngeal neuroanatomy may be helpeful for understanding some of the neurologic diseases of the larynx such as spasmodic disphonia or variability of the vocal cord position in vocal cord paralysis. Further neuroanatomic and physiologic study is needed.