Voice changes after thyroidectomy without recurrent laryngeal nerve injury.

Background: Injury of the inferior laryngeal nerve is not the only cause of voice alteration after thyroidectomy; many patients notice minimal changes immediately after operation, without evidence of inferior laryngeal nerve damage. We hypothesized that there may be other causes for voice modification, such as injuries of the superior laryngeal nerve, prethyroid strap muscles, and cricothyroid muscles. We describe voice changes after total thyroidectomy, without inferior laryngeal nerve injury, using a computer program to objectively compare different patterns of voice.