Kumar R, Borthakur D, Rani N, Singh S
Department of Anatomy, All India Institute of Medical Sciences, New Delhi 110029, India.
Department of Anatomy, All India Institute of Medical Sciences, New Delhi 110029, India.
Morphologie. 2023 Mar;107(356):142-146. doi: 10.1016/j.morpho.2022.01.003. Epub 2022 Feb 9.
Omohyoid muscle is one of the infrahyoid muscles of the neck which consists of two bellies combined at an angle by an intermediate tendon. The inferior belly is a flat, narrow band, which inclines forwards and upwards in the lower part of the neck. It generally originates from the upper border of the scapula, medial to scapular notch. The present case showed unilateral anomalous attachment of the inferior belly of the omohyoid on the medial part of clavicle on left side. Inferior belly was 2.2cm lateral to left sternoclavicular joint with 3.2 and 1.5cm in length and breadth, innervated by ansa cervicalis. Only 3% of this type of variation has been observed until now according to previous literature. Anterior and posterior triangles of neck on both sides of the cadaver were dissected during routine dissection for undergraduate teaching. There was no scapular attachment of inferior belly of the omohyoid on the left side. It was directly originating from the upper surface of the medial side of the left clavicle. Variation in the attachment of inferior belly can have a direct impact on the internal jugular vein and brachial plexus during neck surgeries or trauma due to its close relation to the mentioned structures. This variation should also be taken care during infrahyoid myocutaneus flap extraction for reconstruction surgery of tongue in cases of lingual carcinoma.
肩胛舌骨肌是颈部舌骨下肌群之一，由两个肌腹通过中间腱以一定角度相连组成。下腹是一条扁平、狭窄的带状肌，在颈部下部向前上方倾斜。它通常起自肩胛骨上缘，肩胛切迹内侧。本病例显示左侧肩胛舌骨肌下腹在锁骨内侧部分有单侧异常附着。下腹位于左胸锁关节外侧2.2cm处，长3.2cm，宽1.5cm，由颈袢支配。根据以往文献，迄今为止仅观察到3%的这种类型变异。在本科教学的常规解剖过程中，对尸体两侧的颈前三角和颈后三角进行了解剖。左侧肩胛舌骨肌下腹没有附着于肩胛骨，而是直接起自左锁骨内侧上表面。下腹附着点的变异在颈部手术或创伤时，由于其与颈内静脉和臂丛神经关系密切，可能会对它们产生直接影响。在舌癌病例行舌再造手术取舌骨下肌皮瓣时，也应注意这种变异。
