Abstract：
It is well known that the digastric posterior belly is one of the essential landmarks for facial nerve identification during parotid surgery. While there were multiple reports about variations of the digastric anterior belly, only a few anatomical variations of the posterior belly of the digastric muscle have been described.In this article, we describe an anatomical variation of the posterior belly of digastric muscle found during superficial parotidectomy of a patient with pleomorphic adenoma. This anatomical variation also led to an anatomical variation in the position of the facial nerve.To our knowledge, this is the first report of an absent posterior belly of digastric muscle found during live parotid surgery. The knowledge of current anatomical variation may help to avoid facial nerve injury during parotid surgery and preserve the function of muscles of facial expression.
摘要：
众所周知，腹部后腹部是腮腺手术中识别面神经的重要标志之一。虽然有许多关于腹前腹部变化的报道，仅描述了腹肌后腹的一些解剖学变化。在这篇文章中,我们描述了在多形性腺瘤患者的浅表腮腺切除术中发现的腹肌后腹部的解剖变异。这种解剖变化也导致面神经位置的解剖变化。据我们所知,这是在腮腺活体手术中发现的腹肌后腹部缺失的首次报道。了解当前解剖变异可能有助于避免腮腺手术中的面神经损伤，并保留面部表情肌肉的功能。
