Necdet KOCABIYIK, Bülent YALÇIN, Nurcan ERÇIKTI, R. Shane TUBBS, Selda YILDIZ, Sedat DEVELİ

Anatomical and Clinical Relevance of the Thyroid Foramen

Objective: The thyroid foramen (TF) is an opening on the lamina of the thyroid cartilage. It may be located on the posterosuperiorpart of the lamina or below the superior tubercle. The aim of the present study was to determine the incidence of the foramen in anadult Turkish population and the morphometry, topography, and structures within it, thereby aiding surgeons working in this area.Methods: In 57 formalin-fixed cadaveric laryngeal specimens, 113 (56 right and 57 left) sides were dissected using a surgical microscope.Results: The TF was observed in 6 out of 57 (10.5%) specimens. It was bilateral in 3 (5.3%) specimens; thus, it was observed in 9sides. It was located at (33.3%) or posterior to (66.7%) the oblique line and below the superior tubercle. It was crossed by only anerve in 2 (22.2%) left sides, an artery with a vein in 2 (22.2%) sides, or a neurovascular bundle in 5 (55.6%) sides.Conclusion: The TF is a variation located on the lamina of the thyroid cartilage with an incidence of 2% to 57% in adults. Neurovascularstructures can pass through it. It is important in two aspects: surgical exposure and spread of laryngeal tumors.

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Standring S. Gray’s anatomy : the anatomical basis of clinical practice. Forty-first edition. ed. New York: Elsevier Limited; 2016.
Gilliam C, Renner G. The thyroid foramen: a case report and literature review of a largely unrecognized laryngeal anomaly. Ear Nose Throat J 2009; 88: E4-7.
Raikos A, Paraskevas GK. The thyroid foramen: a systematic review and surgical considerations. Clin Anat 2013; 26: 700-8.
He X, Ye C, Carrat X, Traissac L. Anatomical study of the thyroid foramen in human larynx: a study of 100 dissections. Rev Laryngol Otol Rhinol (Bord) 1999; 120: 127-9.
Kirchner JC, Kirchner JA, Sasaki CT. Anatomic foramina in the thyroid cartilage: incidence and implications for the spread of laryngeal cancer. Ann Otol Rhinol Laryngol 1989; 98: 421-5.
Leon X, Maranillo E, Mirapeix RM, Quer M, Sanudo JR. Foramen thyroideum: a comparative study in embryos, fetuses, and adults. Laryngoscope 1997; 107: 1146-50.
Ramsaroop L, Hurrinarain K, Partab P, Satyapal K. The Incidence of the Foramen Thyroideum in the South African Population. Int J Morphol 2010; 28: 433-8.
Sanudo JR, Maranillo E, Leon X, Mirapeix RM, Orus C, Quer M. An anatomical study of anastomoses between the laryngeal nerves. Laryngoscope 1999; 109: 983-7.
Tanaka S, Shoumura S, Chen H, Nakatani T, Mizukami S. Aberrant branch of the superior laryngeal nerve passing through the thyroid foramen: a macroscopical study. Kaibogaku Zasshi 1997; 72: 251-6.
Partab P, Hurrinarain K, Ramsaroop L, Satyapal KS. Atypical anastomosis of laryngeal nerves. Clin Anat 2006; 19: 651-6.
Muller F, O’Rahilly R, Tucker JA. The human larynx at the end of the embryonic period proper. I. The laryngeal and infrahyoid muscles and their innervation. Acta Otolaryngol 1981; 91: 323-36.
Ortug C, Gunduz T, Sam B. The incidence of the foramen thyroideum in Turkish population. Surg Radiol Anat 2005; 27: 491-4.
Rusu MC, Nimigean V, Banu MA, Cergan R, Niculescu V. The morphology and topography of the superior laryngeal artery. Surg Radiol Anat 2007; 29: 653-60.
Joshi MM, Joshi SS, Joshi SD. The presence of the foramen thyroideum: A cadaveric study in western region of the India. Calicut Med J 2011; 9: e3.
Zemlin WR, Simmon A, Hammel D. The frequency of occurrence of foramen thyroideum in the human larynx. Folia Phoniatr (Basel) 1984; 36: 296-300.
Silva RB, Dias MVF, Fernandes RMP, Babinski MA. A unilateral anomaly of the superior laryngeal artery passing through the thyroid cartilage lamina. Braz J morphol Sci 2005; 22: 41-2.