ABSTRACT
Background: Thyroid gland is one of the vital organs in neck region. It is highly vascularized and variations of the thyroid arteries are frequent and have been well documented in literature. This fact increases the significance of being cautious about thyroid gland while performing surgery in neck region. Objective: To study the morphological anatomy of Inferior thyroid artery and to report the origin of the Inferior thyroid artery, to measure the length of the Inferior thyroid artery from its origin to its entry into the gland, to measure the distance from the midline of the neck to the entry of the Inferior thyroid artery into the thyroid gland and to trace its branches. Method: A total of fifty human cadavers were dissected at anatomy department dissection hall of MGM Medical College, Navi Mumbai, Maharashtra and the measurements were taken as per objective of the study. Results: Inferior thyroid artery originated from the thyrocervical trunk in all cases on the left side. On right side in 48 out of 50 cadavers, it originated from thyrocervical trunk (96%) and in rest two cases it originated from the subclavian artery (4%). Statistically significant variation (p<0.001) of mean length of inferior thyroid artery between the right and left side of cadaver was found, indicating mean length was more on left side. Statistically significant variation (p<0.001) of mean distance from midline to entry of inferior thyroid artery into gland between the right and left side of cadaver was found signifying mean distance from midline was more on the right when compared to the left side. Conclusions: Variations of inferior thyroid arteries are well documented in literature. To keep morbidity to minimum, surgeons should have extensive knowledge of the topographic anatomy and its variations.