Guelfguat M, Nurbhai N, Solounias N
Department of Gross Anatomy, New York College of Osteopathic Medicine, Old Westbury, New York, USA.
Clin Anat. 2001;14(1):42-6. doi: 10.1002/1098-2353(200101)14:1<42::AID-CA1007>3.0.CO;2-O.
A median accessory digastric muscle was revealed during a dissection of the submental region. The muscle was located between the anterior bellies of the digastrics, external to the mylohyoid and deep to the platysma. It appeared as a flat quadrilateral sheet. Its base arose from the front of the body of the hyoid bone near its upper border. Lower portion of the fibers, at the right base of the muscle, initially traveled perpendicular to the lower fibers of the right mylohyoid. The rest of the muscle had a median course, with the cranial end inserting into the mandible between the digastric fossae. The muscle elevated the hyoid bone and depressed the mandible when appropriate stress was applied. No other morphologic abnormalities were found in this region. Aberrant anterior bellies of the digastric muscles are uncommon and occur bilaterally or unilaterally. This observation of a median accessory digastric muscle has not previously been reported. Knowledge of this variant will help to avoid confusion with pathological conditions of the floor of the mouth and the submental region. It is relevant both for the interpretation of radiological images and during surgical procedures such as dissection of the anterior belly of the digastric for a malignant disease and graft positioning.
在颏下区解剖过程中发现了一块中位副二腹肌。该肌肉位于二腹肌前腹之间，下颌舌骨肌外侧，颈阔肌深面。它呈扁平四边形薄片。其基部起自舌骨体靠近上缘的前面。在肌肉右侧基部，纤维的下部最初垂直于右侧下颌舌骨肌的下部纤维走行。肌肉其余部分沿中线走行，其头端插入二腹肌窝之间的下颌骨。当施加适当压力时，该肌肉可上提舌骨并下压下颌骨。该区域未发现其他形态异常。二腹肌前腹异常并不常见，可双侧或单侧出现。此前尚未有关于中位副二腹肌的这种观察报告。了解这种变异将有助于避免与口底和颏下区的病理状况相混淆。这对于解读放射影像以及在诸如因恶性疾病而解剖二腹肌前腹和移植定位等外科手术过程中都具有重要意义。
