Perspective view of the left presigmoid region and suboccipital region after petrosectomy. In this dissection the trapezius muscle inserts on the superior nuchal line of the occiput. The suboccipital triangle is visualized - bordered superiorly by the obliquus capitis superior muscle, inferiorly by the obliquus capitis inferior muscle, and medially by the rectus capitis posterior major. The suboccipital triangle contains the V3 segment of the vertebral artery and the dorsal ramus of the first cervical nerve (suboccipital nerve). The occipital artery runs between the digastric muscle’s insertion on the digastric groove and the obliquus capitis superior. The spinal accessory nerve courses along the levator scapulae muscle. The stylohyoid muscle is also visible here just posterior to the angle of the mandible with its insertion on the styloid process. (Image courtesy of AL Rhoton, Jr.)