A, The detail shows the site of the scalp incision. The C-shaped retroauricular incision provides access for the mastoidectomy, neck dissection, and parotid gland displacement. The scalp flap has been reflected forward to expose the sternocleidomastoid and the posterior part of the parotid gland. B, The more superficial muscles and the posterior belly of the digastric have been reflected to expose the internal jugular vein and the attachment of the superior and inferior oblique to the transverse process of C1. A mastoidectomy has been completed to expose the facial nerve, sigmoid sinus, and capsule of the semicircular canals. C, Enlarged view of the mastoidectomy. The jugular bulb is exposed below the semicircular canals. The chorda tympani arises from the mastoid segment of the facial nerve and passes upward and forward. The tympanic segment of the facial nerve courses below the lateral canal. D, Enlarged view of the caudal part of the exposure shown in C. The facial nerve and styloid process cover the extracranial orifice of the jugular foramen. The facial nerve crosses the lateral surface of the styloid process. The stylomastoid artery arises from the postauricular artery. The rectus capitis lateralis attaches to the jugular process of the occipital bone behind the jugular foramen. (Images courtesy of AL Rhoton, Jr.)