Effectiveness of Intraoperative Neuromonitoring of External Branch of Superior Laryngeal Nerve in Thyroid Surgery

Inclusion Criteria: * Patients who are scheduled to undergo thyroid surgery * Patients who understand and agree to take part in this study Exclusion Criteria: * If the thyroid tumor is suspected to invade adjacent organs (esophagus, trachea, carotid artery, jugular vein etc.) * Patients who are required with lateral compartment neck dissection * Patients with recurrent thyroid cancer * Patients with palsy of recurrent laryngeal nerve or superior laryngeal nerve external branch in the past or present * Patients with a history of vocal cord and larynx disease * History of hyperthyroidism (e.g., Graves' disease) * Taking anticoagulants (aspirin, warfarin, etc.) before surgery * Disorders of coagulation * In the case of women, pregnant women and breastfeeding patients * Patients judged inappropriate by clinical trial researcher