AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI N E AN D SUR G E RY 3 5 ( 2 0 14 ) 25 1–2 5 3

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Traumatic dislocation of intact mandibular condyle into middle cranial fossa Ben Oberman, MD⁎, Dhave Setabutr, MD, David Goldenberg, MD Penn State Hershey Medical Center, Hershey, PA

ARTI CLE I NFO

A BS TRACT

Article history:

Introduction: A 10-year-old girl presented to the Emergency Department with

Received 22 September 2013

temporomandibular joint pain, malocclusion, and trismus after a bicycle accident. Methods: CT of the temporal bones showed displacement of the right mandibular condyle into the middle cranial fossa with small intraparenchymal hemorrhage. The condyle was reduced using closed reduction technique and the patient was placed in maxillomandibular fixation. Results: Complete reduction of the displaced condyle with resultant normal occlusion and persistent bony defect in the temporal bone. Conclusion: In early follow-up assessments the patient has had complete resolution of symptoms with residual bony defect from the site of fracture in the temporal bone. © 2014 Elsevier Inc. All rights reserved.

1.

Introduction

It has been well established in the literature that mandibular condyle injuries after trauma tend to result in fracture at the condylar neck or dislocation of the temporomandibular joint [1,2]. A rarer event is fracturing of the glenoid fossa with mandibular condyle dislocation into the middle cranial fossa. To date, review of the English language shows only 41 case reports of displacement of the intact mandibular condyle into the middle cranial fossa in the Oral and Maxillofacial Surgery literature and one case report in the Neurosurgical literature [2–4]. The authors present a case of a 10-year-old girl who fell off a bicycle with subsequent impact on the chin causing dislocation of the right intact mandibular condyle into the middle cranial fossa.

⁎ Corresponding author. Division of Otolaryngology, Penn State Hershey Medical Center, 500 University Drive, Box H091, Hershey, PA 17033. Tel.: + 1 7175318945. E-mail address: [email protected] (B. Oberman).

2.

Case reports

A previously healthy 10 year old girl sustained facial trauma during a bicycle ride. She was unhelmeted with a friend seated directly behind her on a single-person bicycle. The patient lost control of the bike and subsequently fell over the handlebars landing on concrete with her chin hitting the ground first. She was transferred to the Division of Otolaryngology at Penn State Hershey Medical Center for further care the day of the incident. She denied any loss of consciousness, amnesia, nausea, or vomiting. She complained of an initial rush of air in her right ear and questionable muffled hearing on the right side which had resolved by the time of initial examination. She complained of bilateral temporomandibular joint pain and premature contact of her teeth on the right without any contact of her teeth on the left. Neurosurgery was consulted and determined no neurosurgical intervention was indicated. Significant physical findings were right greater than left tenderness at the temporomandibular joints. Her auricular exam showed a slight blue hue of the right tympanic membrane without frank hemotympanum. Oral exam showed trismus with 1.6 cm inter-incisor distance and posterior displacement of the mandible with deviation to the right, premature contact

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AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI NE AN D SUR G E RY 3 5 ( 2 0 14 ) 25 1–2 5 3

of the right molars, and otherwise intact dentition. There was a 0.6 cm overbite. Her neurological exam was without any focal deficits or signs of cerebrospinal fluid leak. A computed tomography (CT) scan was obtained (Figs. 1 and 2). The patient was taken to the operating room for closed reduction of the mandibular condyle. With downward traction, the posterior molars were depressed and the right mandibular condyle was reduced back into the glenoid fossa. Arch bars were placed using 24-gauge wire and the patient was put into maxillomandibular fixation (MMF). An immediate post-operative CT panorex and facial bones showed reduction of the condyle with about 7 mm gap between the right condyle and fossa joint surfaces (Fig. 3). Post-operatively the patient was able to maintain occlusion while in MMF. She was discharged from the hospital within 48 h after surgery. One week after the patient was placed in MMF the rubber bands were removed in clinic. CT imaging on post-op day 37 showed the right condyle was sitting appropriately in the fossa (Fig. 4).

3.

Discussion

The first case of mandibular condyle displacement into the middle cranial fossa was reported in 1963 by Dingman and Grabb [5]. Including this case, there have been a total of 43 reported cases of displacement of an intact mandibular condyle into the middle cranial fossa. Multiple reviews of prior literature have shown a pediatric and female predilection for this type of injury [2–4,6]. Twentyfour of 43 (56%) cases have been in the pediatric population. Thirty of 43 (70%) cases have been in females. Specifically in the pediatric population, 18 of 24 (75%) cases have occurred in female patients. This type of injury most commonly occurs with high-speed accidents, such as motor vehicle and bicycle accidents [2–4,6]. Despite these commonalities, the structure of the condyle and glenoid fossa is thought to be more of a determinant for this rare type of injury. Da Fonseca indicated that a small, round condyle without accentuated medial or lateral poles could more readily penetrate the glenoid fossa. The typical condyle has a more scroll-shaped appearance to contact the elevated medial and lateral margins of the glenoid fossa. Additionally, a rounded condyle has less surface area available for ligamentous attachment [7]. In these circumstances, a superiorly directed force may allow for an intact condyle to penetrate the thinnest part of the glenoid fossa. Other proposed factors which could predispose a patient for this type of injury include: thicker condylar neck in children compared to adults, increased pneumatization of the temporal bone, lack of posterior dentition, and impact with an open mouth [1,3,4,7–10]. There are mechanisms which may prevent displacement into the cranial cavity as well. A relatively weak condylar neck typically results in subcondylar mandible fractures; this is widely considered to be a "safety mechanism" [2,4,7,11,12]. As aforementioned, the normal scroll shaped condylar head is typically secured by its ligamentous attachments and is larger than the genoid fossa [7]. The meniscus and musculature of the joint additionally help dissipate the impact forces.

Fig. 1 – Intact intracranial dislocation of the right mandibular condyle with a comminuted fracture of the temporal bone.

Clinical features can vary but may include preauricular pain, trismus, unilateral loss in height, laterognathism, premature occlusion on the side of injury, CSF leak, laceration of the external auditory canal, facial nerve paralysis, nausea, hearing deficit, and altered level of consciousness. Diagnosis of the injury is achieved in conjunction with clinical signs and radiographic evidence. Computed tomography (CT) is the preferred imaging study given that diagnosis can be difficult or missed on panorex radiographs [1,4]. If any of the neurologic clinical findings are present, or imaging shows displacement of the condyle into the middle cranial fossa, then Neurosurgical evaluation is indicated. Although unlikely, it is possible to have dural tears, hemorrhage from the middle meningeal artery, or subdural or epidural hematomas [1]. Treatment goals focus on reduction of the condylar head back into the glenoid fossa to prevent cerebral complications while normalizing the occlusion of the patient, re-establishing facial symmetry, and preventing joint ankylosis. Various methods to achieve these goals exist, including closed and open reduction. The type of treatment used is highly individualized. Many types of traction and lever techniques have been reported for closed reduction. Closed reduction is typically considered first as it is reported to be the simplest, safest, and least traumatic [11]. In general, if this method is unsuccessful then open reduction is used. Open reduction is comprised of direct manipulation methods, condylectomy, or condylotomy [4]. Subcondylar osteotomy has been described as well [2]. Various autologous and synthetic materials have been used to reconstruct the fossa if needed [1–4,11].

Fig. 2 – Axial CT scan showing intracranial dislocation of the right mandibular condyle with pneumocephalus.

AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI N E AN D SUR G E RY 3 5 ( 2 0 14 ) 25 1–2 5 3

4.

Fig. 3 – Post-operative reduction of displaced intact right mandibular condyle within the temporomandibular joint.

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Conclusion

We report the case of a 10-year-old girl who suffered dislocation of the right mandibular condyle into the middle cranial fossa after facial trauma. She was treated with closed reduction and MMF with elastics for 7 days. To date, the patient has not had any physical or mechanical sequelae from her injury. This case demonstrates the combination of factors necessary for this type of injury to occur. Early diagnosis and treatment are essential to avoid long-term complications from temporomandibular joint injury.

REFERENCES

Fig. 4 – Post-operative day 37 showing appropriate location of right mandibular condyle within the temporomandibular joint.

Many reports suggest placing patients in maxillomandibular fixation with wires or elastics for at least 10–14 days to maintain occlusion and prevent recurrence of dislocation [2]. Some authors advocate the use of elastics as functional training can be performed simultaneously [11]. A CT scan post-operatively should also be obtained to show position of the condyle within the glenoid fossa and rule out any iatrogenic intracranial injuries. In pediatric patients, particularly those less than 10 years of age, mandibular growth asymmetry has been reported [2,10]. This is believed to be due to damage of the growth center of the condyle. This may require further surgical intervention but currently there are no reports regarding surgical correction.

[1] Barron R, Kainulainen V, Gusenbauer A, et al. Management of traumatic dislocation of the mandibular condyle into the middle cranial fossa. J Can Dent Assoc 2002;68:676–80. [2] Harstall R, Gratz K, Zwahlen R. Mandibular condyle dislocation into the middle cranial fossa: a case report and review of literature. J Trauma 2005;59:1495–503. [3] Magge S, Chen HI, Heuer G, et al. Dislocation of the mandible into the middle cranial fossa: case report. J Neurosurg 2007;107(Suppl 1):75–8. [4] Ohura N, Ichioka S, Sudo T, et al. Dislocation of the bilateral mandibular condyle into the middle cranial fossa: review of the literature and clinical experience. J Oral Maxillofac Surg 2006;64:1165–72. [5] Dingman RO, Grabb WE. Mandibular laterognathism. Plast Reconstr Surg 1963;31:563–75. [6] Kroetsch L, Brook AL, Kader A, et al. Traumatic dislocation of the mandibular condyle into the middle cranial fossa: report of a case, review of the literature, and a proposal management protocol. J Oral Maxillofac Surg 2001;59:88–94. [7] Da Fonseca GD. Experimental study on fractures of the mandibular condylar process. Int J Oral Surg 1974;3:89–101. [8] Smith RR. Essentials of neurosurgery. Philadelphia (PA): Lippincott; 1980. p. 6, 108, 118-123. [9] Chuong R. Management of mandibular condyle penetration into the middle cranial fossa: case report. J Oral Maxillofac Surg 1994;52:880–4. [10] Musgrove BT. Dislocation of the mandibular condyle into the middle cranial fossa. Br J Oral Maxillofac Surg 1986;24:22–7. [11] Man C, Zhu SS, Chen S, et al. Dislocation of the intact mandibular condyle into the middle cranial fossa: a case report. Int J Oral Maxillofac Surg 2011;40:118–20. [12] Vaezi T, Rajaei SA, Abrishami MH, et al. Dislocation of the mandibular condyle into the middle cranial fossa: a case report. J Oral Maxillofac Surg 2013.

Traumatic dislocation of intact mandibular condyle into middle cranial fossa.

A 10-year-old girl presented to the Emergency Department with temporomandibular joint pain, malocclusion, and trismus after a bicycle accident...
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