The thyroid foramen

Abstract

This study presents an analytic review about the trait of the thyroid foramen. A detailed description about the demographics, frequency, embryology, morphometry, possible content, topography, clinical and surgical considerations is provided. The overall frequency was 28.3% in adults, 15% in children and neonates, 40.6% in embryos and fetuses. The content of the thyroid foramina was a neurovascular bundle in 41.2% of studies. An equal number of studies define a nerve as the common content, while only in 17.6% the usual content was a vessel. Interestingly, in 11.8% the content was just connective tissue or a pit. An updated classification is presented taking into account all the possible content that can cross through a thyroid foramen. The variant is of high interest for surgeons intervening in the larynx due to potential complications such as local bleeding and unwanted neural impairment. The oblique line of the thyroid lamina acts as the best topographical landmark to identify any aberrant anatomy related to a thyroid foramen.

Injuries of the isolated larynx-hyoid complex in post-mortem computed tomography (PMCT) and post-mortem fine preparation (PMFP) - a comparison of 54 forensic cases

“…The rather high incidence of 38.9% in the cohort is probably due to the ability of PMCT to visualize bony and cartilaginous samples, while observations based on X-rays alone miss these cartilaginous samples. The incidence of foramina thyroidea due to irregular ossification of the thyroidal shields was comparable to the literature (33.3% vs. 28.3%) [ 16 ]. An agenesis of the thyroidal horn or an aplasia of the hyoidal horns is comparatively rare but may also imitate dislocated fractures, especially in cases of advanced decay or in victims with deep snags [ 29 ].…”

“…The degree of dislocation was documented for each fracture in each subarea on a 4-point Likert scale [ 14 ]: 0 = no fracture, 1 = incomplete fracture (fissure), 2 = non-displaced fracture, and 3 = displaced fracture. The windowing that was used to find a definite diagnosis (bone or soft tissue window or both) and common normal variants (foramen thyroideum, cartilago triticea, asymmetry/agenesis/aplasia of a thyroidal or hyoidal horn, Eagle syndrome) were documented [ 15 , 16 ].…”

Foramen in the Shield: Foramen Thyroideum

“…Interestingly, in 11.8%, the content was just connective tissue or a pit. (7) In the present study, foramen thyroideum was found in seven larynges. In the seven larynges, there were ten foramens.…”

“…The oblique line of the thyroid lamina acts as the best topographical landmark to identify any aberrant anatomy related to a thyroid foramen. (7) CONCLUSION Foramen thyroideum is present in significant number of cases (11%), so it requires further studies in different part of Indian population to establish its incidence as a whole. It cannot be neglected due to surgical and other clinical significance.…”

Early Internal Branch of Superior Laryngeal Nerve Bifurcation Passes Through Double Thyroid Foramen

“…1 Dimensions, incidence, and content vary. [2][3][4] The presence of bilateral foramen was observed in 9% of studied specimens, whereas double thyroid foramen (on the same side) was detected only in a few occasions with its frequency ranging from 0.6% to 3.3% across studies. 4 Awareness of the possible presence of a thyroid foramen is extremely beneficial to the head and neck surgeon.…”