C.E. Credit. Maxillary Third Molar Displacement into the Infratemporal Fossa: The Diagnosis and Management of a Rare Dentoalveolar Complication in Routine Oral and Maxillofacial Surgery

ABSTRACT

Background

The infratemporal fossa is a space located along the lateral skull into which an upper wisdom tooth can be displaced during the extraction of a maxillary third molar. Although this complication is rare, many patients remain at risk even during a routine outpatient visit with an experienced oral and maxillofacial surgeon. To retrieve the displaced wisdom tooth localized inferior and medial to the ipsilateral zygomatic arch, surgical exploration of this space can be done using a variety of techniques described in the literature and in this case.

Case Description

This article presents a case in which a right upper wisdom tooth was apically displaced into the infratemporal fossa. Cone-beam computed tomography aided in verifying the exact position of the third molar and subsequent surgical planning. In this case, an immediate approach was used with minimal intraoral dissection into the posterior maxillary vestibule. In doing so, sufficient access and visibility were established for successful retrieval of the tooth in the same visit by extending the original incision site and without the need for any additional procedures thereafter. This article also offers an overview of potential retrieval options as described by the literature.

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KEYWORDS:

• Third molar
• displacement
• cone beam
• infratemporal fossa
• dissection
• wisdom tooth

Case Report

A 15-year-old male with unremarkable medical history was scheduled for extraction of teeth #1, 16, 17, and 32. The patient had received a consultation at a prior visit. At this encounter, he arrived with nil per os (NPO) as instructed and was present with both parents in attendance at check-in.

Pre-operatively, his radiographs were examined. It was noted that his maxillary third molars were bilaterally positioned significantly apical when compared to the occlusal tables of his second and first molars. They approximated his maxillary sinuses bilaterally and demonstrated tooth buds with incompletely formed root apices. Intravenous sedation (IVS) was initiated, airway patency was maintained, and local anesthesia was applied as the procedure was initiated. A flap was released to access the patient’s right maxillary third molar, tooth #1. During application of firm and direct pressure using the offset spade elevator and matching counter-pressure by assistants, the tooth had become displaced superiorly and was now completely missing from view. It was immediately suspected that the tooth had been propelled into the right infratemporal fossa space. Localization of the missing third molar was of utmost importance. The remaining three wisdom teeth were extracted without complication. Next, IVS was reversed and a new cone-beam computed tomography (CBCT) was obtained to visualize the missing tooth. As predicted, tooth #1 laid horizontally angled and in the infratemporal space.

Subsequently, a discussion was held post-operatively with the patient and his parents which reviewed the options for treatment including immediate versus delayed approaches to retrieval. The patient agreed to go back under sedation right away to permit an attempt to retrieve the tooth buried in his right infratemporal space. Once re-sedated, the patient’s right maxillary vestibule adjacent to his second and third molar space was explored using a 15 Bard-parker blade for expansion of the initial incision and scissors to carefully dissect the soft tissue with scissors and a blunt tipped hemostat. The hidden third molar was now visualized and removed from the infratemporal. 3-0 chromic gut sutures were applied to obtain primary closure. The IVS was reversed and the patient and the family were informed of the success of the second surgery. The patient was prescribed a course of pain medications for the procedure endured as well as a course of 500 mg amoxicillin TID for 7 days.

Figure 1. Three-dimensional cone beam computed tomography showing displacement of right maxillary third molar into the infratemporal fossa (Figure 1(a) 3D reconstruction, Figure 1(b) axial view, Figure 1(c) coronal view).

Figure 2. Two-dimensional panoramic radiograph (OPG, Panorex) images of the patient (Figure 2(a) pre-operative, Figure 2(b) post-operative).

Discussion

In examining etiologies of the localization of maxillary third molars to the infratemporal fossa, a primary culprit is obscured clinical visibility intraoperatively coupled with heavy force applied during the extraction.¹ Typically, when wisdom teeth are improperly displaced, they enter the maxillary sinus. However, on occasion, they may also enter the infratemporal fossa. The risks of retrieving such a tooth include severing of vessels including the maxillary artery or causing permanent loss of sensation to the trigeminal nerve V2 distribution by direct injury to the maxillary nerve.² Risks and benefits of the procedure must be weighed when considering continuing to attempt to retrieve the molar during the procedure versus rescheduling the patient for extraction at a separate appointment or even under general anesthesia at an in-patient hospital-based operating room setting.³

There are pros and cons for immediate versus delayed retrieval. Each option must be weighed with consideration for the circumstances surrounding each individual case. Access to the displaced third molar is a major advantage of immediate retrieval as the tissues may be more visible; an incision site could be made or further extended. However, since the tooth has already been mobilized, immediate pursuit may risk further displacement via attempts to retrieve it. This risk is often managed via application of a delayed retrieval approach. In this manner, re-accessing the site two to three weeks postoperatively would allow sufficient time for the soft tissues to heal and a fibrotic capsule to form around the tooth likely increasing its stability and decreasing the odds of worsening the displacement. Additionally, decreased bleeding and edema via a delayed approach would allow for better visualization and as well as potentially palpation of the tooth. Just prior to delayed retrieval, a repeat CBCT is advised in the event that the tooth has since migrated. A final option is following up and not treating asymptomatic displaced or ectopic third molars in order to prevent serious complications.⁴

Improper retrieval technique could lead to exacerbation and further displacement of the tooth into the lateral pharyngeal space, which extends superiorly from the inferior portion of the sphenoid bone and inferiorly to the hyoid.⁵ To prevent this and to ensure a successful surgery for the management of this complication, sufficient visibility must be ensured when retrieving teeth displaced into the infratemporal fossa.² Firstly proper imaging should be obtained pre-operatively and immediately after the occurrence of the complication to localize the tooth. This includes panorex and CBCT. If available, image-guided retrieval could be applied in diagnostics to reveal the location intraoperatively.⁶ This is accomplished by the correct application of full-thickness flap designs and accesses including but are not limited to vertical releasing incisions, marginal incision from the maxillary tuberosity to the mesial papilla of the first molar, the use of fluoroscopic imaging and the Gillies approach through a small incision when retrieving a tooth displaced into the infratemporal space,⁷ a trans-sinusoidal approach, image-guided active navigation,⁸ or even extraoral approaches as deemed necessary.⁹ In the case of an exacerbated complication such as further displacement into the lateral pharyngeal space,⁵ a transoral approach could be applied via one of two approaches: 1) A dissection along the anterior border of the mandibular ramus medial to the medial masseter and lateral to the superior constrictor muscle of the pharynx, or 2) often less traumatically, access via the tonsillar fossa. Finally, a review of the literature also revealed use of an intraoral flap with subsequent coronoid process resection to extend the field of view in severe cases.²

Major risk factors contributing to the occurrence of this complication include a relatively young patient age, due to early development of the tooth, as well as high degree of impaction. Variables that contribute to a relatively young age being a strong risk factor for displacement of a third molar into the infratemporal space include the following: 1) Relatively softer alveolar bone, 2) higher degree of vertical impaction of maxillary third molars prior to eruption, and 3) commonly incomplete tooth root formation and therefore higher rate of mobilization on attempts to extract the third molar. In addition, if the procedure is attempted under local anesthesia only, behavioral management comes into consideration including risks of intraoperative head movement which could ultimately contribute to infratemporal space displacement of a maxillary third molar.

To prevent this type of complication, certain precautions must be taken. These include during initial extraction of the non-displaced wisdom tooth and in treatment of the aforementioned complication itself, an adequate flap design must be formed in order to ensure sufficient visibility to the operator.¹⁰ Intravenous sedation is preferred over local anesthesia depending on the degree of impaction, root development, and angulation. Finally, the assistants should be well trained to maintain ideally positioned retraction and to support the patient’s head position in a fixed and sturdy position that allows for maximum visibility to the oral surgeon while minimizing any intraoperative movement.

Postoperative management whether the treatment is via immediate or delayed retrieval should include antibiotics for a minimum of 7–10 days, which have shown to reduce swelling and pain after such a procedure.¹¹ The preferred options include augmentin 875/125 mg PO BID. Alternatively, if the patient has a penicillin allergy, appropriate options include clindamycin 300 mg PO TID or azithromycin 500 mg PO QD for day 1 followed by 250 mg PO QD for the remaining course. However, prolonged administration of antibiotics is typically not justified and may result in serious health consequences. In the case of this complication, antibiotic use benefits vastly outweigh their risks as contaminated oral flora is introduced into the infratemporal space for days or weeks.

This is moreso the case in the delayed retrieval approach as a nidus for infection would remain in situ until the third molar is finally extracted weeks later. On the other hand, if the tooth is retrieved immediately, typically a larger incision is applied for the exploration of the infratemporal fossa, which would also necessitate antibiotic use postoperatively, but to a lesser degree. Overall, whether the surgeon applies an immediate or delayed approach is dependent on patient and clinician factors. If the third molar is localized in position and angulation that may safely permit its immediate retrieval, an attempt could be made such as in this case. However, consideration must also be given to the delayed retrieval approach and postoperative management is largely the same.

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/19424396.2024.2313777

Additional information

Notes on contributors

Alexander Litrel

Alexander Litrel, DDS, is a resident doctor graduate of Columbia University (DDS). He is a currently completing his internship in Oral and Maxillofacial Surgery at Montefiore Medical Center and received training in general dentistry at Jacobi Medical Center with the completion of general practice residency.

Shahrokh C. Bagheri

Shahrokh C. Bagheri, DMD, MD, FACS, FICD, is a dual doctor graduate of Harvard University (DMD, cum laude, class marshal) and Emory University (MD). He is an internationally recognized surgeon and leader in the field of Oral and Maxillofacial Surgery (OMFS). His current and past positions include Division Chief of Northside Hospital in Atlanta, University faculty appointments, Editorial Board member of the Journal of Oral and Maxillofacial Surgery and Consultant to American Dental Association Council on Scientific Affairs.