Progressive Facial Paralysis Caused by Heterotopic Ossification of the Stylohyoid Ligament

A 56-year-old man with a history of a right skull base fracture from a fall in the military 30 years ago presented to clinic with 6 months of progressive right-sided facial paralysis and a 1-year history of worsening odynophagia and dysphagia. He had been previously diagnosed at an outside facility with Bell’s palsy. Upon examination, the patient had House-Brackmann grade IV facial palsy on the right, tenderness to palpation over the right mastoid tip, and a palpable firm mass below the right mandible with fixation of the hyoid bone. Computed tomography of the neck showed a calcified mass extending from the right posterior skull base to the hyoid (Figure 1). There was narrowing of the facial canal as the nerve exits the stylomastoid foramen. The patient underwent transcervical resection of the calcified mass and mastoidectomy with facial nerve drill-out. During the mastoidectomy, there was evidence of facial nerve impingement as it exited the skull base. Although the nerve was grossly intact, it could not be stimulated. A partial parotidectomy and level II-IV neck dissection were performed to provide access for removal of the mass (Figure 2). Eighteen months postoperatively, the patient still has House-Brackmann grade IV on the right. His dysphagia and odynophagia improved but did not completely resolve. University of Florida Institutional Review Board exemption was obtained for this case report.