A STUDY OF FORAMINA THYROIDEUM

Background: A foramen in the lamina of thyroid cartilage is an occasional opening existing in one or both thyroid laminae which may or may not contain a neurovascular component. Foramen was first described by Segond in 1847. Materials and methods: Larynx specimens were collected from Department of Forensic Medicine Mysore Medical College. 62 Larynx specimens were collected, 31 male and 31 female, and fixed in 10% formalin solution for 2-3 weeks. Careful dissection was done to separate thyroid cartilage and following observations were made. Location of foramen, regarding the side of lamina and its relation to oblique line was noted. Size, shape and measurements were noted. Results: Foramina were observed in the laminae of 9 thyroid cartilages in females and 6 in male specimens. 1 male specimen showed bilateral foramina thyroideum. Among 16 Foramina Thyroideum (FT), 13 were on right lamina and 3 on left lamina. Shape of FT was round in 9 specimens and oval in 7 specimens. 10 FT were located in front of oblique line, 5 were behind and 1 was on the line. Size of FT range from 1mm - 5.67mm, close to upper boarder in 13 specimens and 3 were in the middle.1 specimen showed presence of superior laryngeal vessels in FT. Conclusions: Incidence of FT in the present study was 25.8%.To conclude presence of FT being a rare variation clinicians need to be aware of the possible contents such as external and internal laryngeal nerve communication and presence of superior laryngeal vessels before undertaking surgical procedures.