the sinus. Additionally, the sinus can be irrigated through the OAC and suction placed at the opening in an attempt to flush the tooth or root segment out. If the segment is visualized, the opening can be enlarged to allow retrieval. If this is unsuccessful, the surgeon should abandon further attempts at removal through the socket and remove the tooth segment via a Caldwell–Luc approach into the maxillary sinus. This can be completed at the time of initial surgery or in a delayed secondary procedure. If delayed retrieval is planned, the patient should be placed on antibiotics and decongestants, and the OAC closed as described previously [3, 4].
The retrieval of a maxillary third molar displaced into the infratemporal fossa can be complicated by bleeding from the pterygoid plexus, poor visualization, and inability to locate and stabilize the tooth [25]. In general, the tooth is located lateral to the lateral pterygoid plate and inferior to the lateral pterygoid muscle. Lateral and posteroanterior cephalometric films can assist in localizing the tooth, but computed tomography (CT) is preferred if available (Figure 2.7a–f). The surgeon should extend the original incision distally to the tonsillar fauces and, with blunt dissection, attempt to locate the tooth. If this attempt is unsuccessful, the tooth should be left in place and the patient placed on antibiotics. Blind, or limited visualization, attempts to grab or probe for the tooth should be avoided since injury to adjacent structures or further displacement of the tooth can occur. If asymptomatic, the tooth can be left in place and the patient followed closely. Pain, infection, limitation of opening (from tooth impingement on the coronoid process), and patient desire are all indications for removal. This is completed in four to six weeks to allow for fibrosis to occur, the tooth to stabilize, and appropriate imaging (CT, cone‐beam CT [CBCT]) to be obtained. Multiple approaches have been described in the literature, including CT‐guided surgery, needle‐guided fluoroscopic retrieval, transoral retrieval, and hemicoronal flaps [3, 4, 25].
Fig. 2.7. (a) Coronal view CT demonstrating tooth #16 displacement into the infratemporal fossa. (b) Axial view CT demonstrating tooth #16 displacement into the infratemporal fossa and located between the coronoid process and zygoma, limiting maximum incisal opening. (c) Positioning for planned intraoperative navigation. (d) Utilizing a small incision, the navigation system is utilized to locate the displaced tooth. (e) Intraoperative navigation to triangulate the position for removal with minimal dissection. (f) Removed tooth #16 specimen.
Displaced mandibular third molars are most often located in the submandibular space, inferior to the mylohyoid muscle. Attempts at removal should begin with digital pressure against the lingual surface of the mandible to force the root segment back into the mouth/extraction site. The opening into the floor of the mouth can be enlarged slightly to assist in retrieval; however, this should be completed cautiously to avoid injury to the nearby LN. A lingual full thickness flap can be carefully reflected and the mylohyoid muscle incised to gain access to the submandibular space. Due to limited space, hemorrhage, and poor visibility, it may be very difficult to remove the tooth or root segment via this method. Allowing for fibrosis to occur and returning at a later date to remove the tooth or root is acceptable. Often, this is completed via an extraoral approach in the operating room and after CT scanning completed. Yeh has described an intraoral/extraoral approach where a 4‐mm skin incision allowed for insertion of a hemostat and/or Kelly forceps and stabilization of the tooth, while via an intraoral lingual full thickness flap, the tooth was located and removed [26].
Displacement of a root into the IAC should be approached with caution. Attempts at retrieval can further damage the IAN or further displace the root. If the root segment was not infected and the patient does not complain of neurological findings, leaving the root segment may be acceptable. If the root is infected, or the patient has complaints of neurological involvement, it must be removed with caution and consideration made for referral to a microneurosurgeon to evaluate whether nerve repair may be necessary [4].
Aspiration/Ingestion
Etiology: no or inappropriate use of pharyngeal packs/screens
Management: suction, Heimlich maneuver, laryngoscopy, bronchoscopy
The incidence of foreign body, or tooth, aspiration or ingestion is likely underreported in the literature. Approximately 92.5% of objects are ingested, while the remaining 7.5% are aspirated [3, 4]. Patients undergoing the surgical removal of third molars are often sedated, resulting in their gag and cough reflexes being obtunded. A pharyngeal curtain should be utilized in all patients to prevent aspiration or ingestion during surgery. If the patient is not coughing or in any respiratory distress, it is likely the tooth has been ingested and prompt referral to an emergency room for abdominal and chest radiographs to confirm the location of the object should be made. Coughing that continues or leads to respiratory distress should alert the surgeon to probable aspiration. An attempt to suction the object from the oral pharynx should be made and basic life support (BLS) and, if necessary, advanced cardiac life support (ACLS) protocols activated. The Heimlich maneuver should be used to attempt to dislodge the object. If a patient becomes cyanotic or unconscious, an attempt at retrieval under direct laryngoscopy can be made, if the surgeon's office has the necessary equipment. If this fails, emergent cricothyrotomy may be necessary to secure the airway. An object that passes through the vocal chords will most likely end up in the right main stem bronchus or right lung (right mainstem bronchus has a more vertical takeoff from the trachea than the left side), and the patient should be transported to the emergency room and arrangements should be made for bronchoscopy for object retrieval by an experienced clinician (Figure 2.8).
Fig. 2.8. Chest X‐ray demonstrating aspiration of a tooth.
Neurological Complications
Etiology: failure to recognize risk factors, individual patient anatomy, poor surgical technique
Management: monitoring, serial neurosensory examination, microneurosurgery, medical management
The incidence of neurological complications as a result of third molar surgery ranges from 0.4% to 11% [1, 2, 5, 6, 27]. Injury to the IAN is associated with spontaneous recovery in 96% of cases, and spontaneous recovery of LN injury is approximately 87% [27]. Sensory deficits that last longer than one year are likely to be permanent, and spontaneous recovery of sensation should begin within the first eight weeks following surgery [27]. According to the AAOMS White Paper on third molars, the incidence of IAN injury one to seven days postoperatively is 1–5%, while persistent alteration in sensation after six months ranges from 0% to 0.9% [1]. LN injury one day after surgery was reported in 0.4–1.5% of patients, with persistent sensory alteration at six months in 0–0.5% of patients [1]. The use of lingual retraction increased the incidence of temporary paresthesia; however, the incidence of persistent neurosensory deficit remained the same. In a study by Tay et al., 192 IANs in 170 patients were exposed during third molar surgery. Twenty percent reported paresthesia at one week follow‐up, and 6% had persistent paresthesia at one year [28, 29].
An increased risk of a persistent neurosensory deficit following an IAN injury is associated with increased age, female gender, complete bony impaction, horizontal tooth angulation, sectioning of the tooth multiple times, bone removal, surgeon experience, and duration of surgery [27]. Additionally, Rood et al. has described seven radiographic predictors of potential nerve injury [30, 31]. The most significant have been found to include diversion of the IAC, darkening of the roots, and interruption of the white line of