Infrahyoid myotomy is defined as a surgery in which the sternohyoid, omohyoid and sternothyroid muscles are sectioned bilaterally at their insertions to the hyoid bone or to the thyroid cartilage. The purpose of the operation is to elevate the hyoid bone and the larynx with ease during deglutition and articulation. Animal experiments revealed that the degree of elevation of the hyoid bone and the larynx during deglutition was increased after the section the sternohyoid and sternothyroid muscles. Infrahyoid myotomy in three clinical cases resulted in improvement in swallowing and speech to some extent.
