Fig. 2From: Is identification and dissection of the external laryngeal nerve necessary during thyroidectomy? A prospective studyCernea classification. Type I: The EBSLN crosses the STA more than 1 cm above the upper edge of the superior thyroid pole. Type IIa: The EBSLN crosses the STA less than 1 cm above the upper edge of the superior thyroid pole. Type IIb: The EBSLN crosses the STA below the upper edge of the superior thyroid poleBack to article page