An Unusual Case of Trismus and Epistaxis

Abstract

Surgical access to the ITF is difficult secondary to its relatively concealed location. The anterior and posterior borders of the ITF include posterior surface of the maxilla and the mastoid and tympanic portions of the temporal bone respectively. Superiorly the space is defined by the greater wing of the sphenoid bone and the squamous portion of the temporal bone while the inferior limit is defined by the angle of the mandible and superior extent of the posterior belly of the digastric muscle. The medial limit of the space is the pterygoid process of the sphenoid bone, the lateral limit is the clivus and the inferior surface of the petrous portion of the temporal bone, and the lateral extent is further framed by the zygomatic arch and the ascending ramus of the mandible (1). The nature of the surgical pathology will determine the most suitable approach to maximize the exposure and minimize the surgical morbidity. Surgical approaches to the ITF can be divided into anterior (transfacial, transmaxillary and transoral), lateral (transzygomatic and lateral infratemporal) and inferior (transmandibular and transcervical) (2,3). There are several approaches to the ITF that have been described in foreign body removal. The most reported ITF foreign bodies are displaced third maxillary molar teeth. Orr described removal of a displaced molar through an intraoral approach combined with the insertion of needle behind the zygomatic arch to manipulate the tooth into the intraoral incision (4). There are reports of maxillary molars displaced into the ITF being removed utilizing a temporal approach and a hemicoronal approach (5,6). In a case report by Lee et al. describing a nail gun injury in which a nail passed through the right superior sublabial sulcus and terminated in the ITF a preauricular approach was used to access this space. After disarticulation of the zygomatic arch and reflection of the temporalis muscle the head of the nail was visualized just lateral to the orbital wall. Ultimately the nail was removed along its original vector of entrance through the sublabial sulcus (7). Removal of long, thin foreign bodies that are introduced by impalement is best accomplished using the vector in which they are introduced to avoid unnecessary damage to adjacent tissues. The location and apparent course of the piece of glass in our case were suitable for a modified Blair approach. This was the safest and least morbid way to identify the large foreign body that traversed the plane of the facial nerve. This permitted minimal sacrifice of a small zygomatic branch of the facial nerve in a controlled fashion and facilitated primary neurorrhaphy. This can be done safely if the appropriate surgical approach and dissection have been carried out such that control of bleeding at the distal end of the foreign body can be readily achieved if needed upon the object’s removal. In our case nasal endoscopy was utilized to visualize the distal tip of the glass shard within the nasal cavity and instruments were available for potential epistaxis control. Shemen et al. described the removal of a pen tip under local anesthesia after needle wire localization (8). They employed a vertical incision in the hairline just above the level of the zygoma and approached the ITF through the temporalis muscle. Needle localization was helpful given the small size of the foreign body. Neff et al. described endoscopic removal of a bullet fragment from the ITF with intraoperative fluoroscopy (9). The large size of the piece of glass and entrance scar on the cheek in our case obviated the need for fluoroscopic or needle wire localization. Preoperative imaging was essential to establishing a diagnosis and informative in surgical planning in this case. Given the intimate association with cranial nerves and major vascular structures computed tomography or magnetic resonance imaging should be used to define the trajectory of the foreign body and assess the extent of injury. DISCUSSION (Cont)