A) Anterior border of the posterior belly of the digastric muscle.
B) Posterior border of the posterior belly of the digastric muscle.
C) Superior border of the posterior belly of the digastric muscle.
D) Inferior border of the posterior belly of the digastric muscle.
✅ Correct Answer: C) Superior border of the posterior belly of the digastric muscle.
Explanation:
The superior aspect of the posterior belly of the digastric muscle serves as a reliable intraoperative landmark for locating the facial nerve. Understanding this landmark enhances surgical precision and reduces complications.
Key Anatomical Landmarks for Facial Nerve Identification:
- Facial nerve lies 2-4 mm inferior to the tympanomastoid suture line, making the superior border a consistent guide.
- Tragal “pointer” provides a reference about 1 cm deep, slightly anterior and inferior.
- Tendon of posterior belly attaches to mastoid bone hiding the nerve about 1 cm deep.
- Tympanomastoid suture marks a critical point 6-8 mm deep.
- Proximity to the styloid process is important during surgery.
Mastering these landmarks improves surgical safety and outcomes.
