Int. J. Oral Maxillofac. Surg. 2015; 44: 864–870 http://dx.doi.org/10.1016/j.ijom.2014.12.016, available online at http://www.sciencedirect.com Case Report TMJ Disorders 1 1, 1 Y. He , Y. Zhang , Z.-L. Li , 1 2 2 J.-G. An , Z.-Q. Yi , S.-D. Bao Treatment of traumatic 1 Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Haidian District, 2 dislocation of the mandibular Beijing, PR China; Department of Neurosurgery, Peking University First Hospital, Xicheng District, Beijing, PR China condyle into the cranial fossa: development of a probable treatment algorithm Y. He, Y. Zhang, Z.-L. Li, J.-G. An, Z.-Q. Yi, S.-D. Bao: Treatment of traumatic dislocation of the mandibular condyle into the cranial fossa: development of a probable treatment algorithm. Int. J. Oral Maxillofac. Surg. 2015; 44: 864–870. # 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. This study summarizes our experience of treating three rare cases of traumatic superior dislocation of the mandibular condyle into the cranial fossa and provides a potential treatment algorithm. Between the years 2002 and 2012, three patients with traumatic superior dislocation of the mandibular condyle into the cranial fossa were admitted to our department. After evaluating the interval from injury to treatment, the associated facial injuries including neurological complications, and the computed tomography imaging findings, an individualized treatment plan was developed for each patient. One patient underwent closed reduction under general anaesthesia. Two patients underwent open reduction with craniotomy and glenoid fossa reconstruction. All three patients were followed up for 1 year. Mouth opening and occlusal function recovered well, but all patients had mandibular deviation during mouth opening. Closed reduction under general anaesthesia, open surgical reduction with craniotomy, and mandibular condylotomy Key words: mandibular condyle; superior dis- are the three main treatment methods for traumatic superior dislocation of the location; middle cranial fossa. mandibular condyle into the cranial fossa. The treatment method should be selected on the basis of the interval from injury to treatment, associated facial injuries Accepted for publication 23 December 2014 including neurological complications, and computed tomography imaging findings. Available online 7 February 2015 When the mandibular condyle collides the anatomical ‘safety mechanism’ for the certain anatomical or physiological con- with the top of the glenoid fossa of the skull base. For this reason, the incidence ditions, the mandibular condyle may pen- temporomandibular joint (TMJ) under rel- of mandibular condylar fracture is rela- etrate the mandibular fossa superiorly into atively strong external force, mandibular tively high, representing 27–43% of man- the cranial fossa, and result in dislocation 1–3 condylar neck fractures often occur due to dibular fractures. However, under of the mandibular condyle into the cranial 0901-5027/070864 + 07 # 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Traumatic dislocation of the mandibular condyle 865 fossa (DMCCF). Such a situation is ex- rological complications, but other injuries had also suffered a delayed fracture of the tremely rare. DMCCF was first reported in may include mandibular fracture, brain mandibular body. 1963, and up until 2012, only 45 cases had concussion, brain contusion, intracranial Spiral CT was carried out for all three been reported sporadically in the English haemorrhage, epidural haematoma, cere- patients on admission. After evaluating 4 language literature. The average age of brospinal fluid leakage, hearing loss, ear the time interval between injury and these patients at the time of injury was canal injury, and facial nerve injury. Neu- treatment, the associated facial injuries, 23.4 years and more than half were minors rological complications and other associ- and the CT imaging findings such as the younger than 18 years of age. This injury ated facial injuries are important factors depth of penetration of the condyle into is more common in female patients and the affecting the treatment strategy for the cranial fossa, we developed different main cause is high-energy and high-speed DMCCF. treatment plans for the patients. One traffic accidents. Three procedures have been reported patient underwent closed reduction un- 4,8–23 Some special anatomical and physio- for the treatment of DMCCF : (1) der general anaesthesia and the other logical states may help explain the mech- closed reduction under general anaesthe- two patients underwent open surgical anism of this injury. Firstly, a small, round sia, (2) open surgical reduction with cra- reduction and glenoid reconstruction condyle may penetrate the glenoid fossa niotomy, and (3) condylotomy. An (Table 1). more easily than a normal, scroll-shaped individualized treatment based on the condyle, which has been demonstrated patient’s status has been emphasized, 5 Closed reduction experimentally by da Fonseca. Yale and many scholars recommend similar 6 4,9,21 et al. reported that 2.8% of cadavers in treatment procedures. Case 1 was a 13-year-old female patient. their study had this kind of mandibular Between the years 2002 and 2012, three The patient had accidentally fallen on her condyle. In addition, this morphology of patients with DMCCF were admitted to chin during exercise. After the injury she the mandibular condyles is also found in our hospital. These three patients had in- experienced limitations of mouth opening 7 10-year-old children, which may explain juries with different features and received and malocclusion. The patient visited our why this type of injury occurs most often individualized treatment. The treatment of hospital 6 h after the injury and no neuro- in young people. Secondly, a high degree these three patients is summarized below. logical complication was found. Physical of pneumatization of the temporal bone We also reviewed the previous literature examination showed deviation of the man- weakens the top of the glenoid fossa and on this subject and concluded that the time dible towards the right side, 15 mm of thereby reduces the resistance of the bone interval between injury and treatment, the mouth opening, an anterior open bite, 8,9 to impact. Thirdly, the absence of pos- associated facial injuries including neuro- and right-side premature contact of the terior occlusion may lead to the conse- logical complications, and CT imaging posterior teeth. CT images showed a quence that any violent force is transferred findings are the main factors affecting right-side glenoid fossa fracture and directly to the TMJ along the ramus with- the treatment strategy. superior displacement of the right-side out being distributed to the maxilla via the mandibular condyle into the skull teeth. Finally, if the patient opens the (Fig. 1). The patient was undergoing or- mouth at the time of impact to the chin, thodontic treatment. Materials and methods the violent force can be transferred direct- Intermaxillary elastic traction was ap- ly to the condyle, which as mentioned During the years 2002 to 2012, three plied for 4 days, but failed. CT showed above, lacks support from the teeth. patients with rare DMCCF were admitted incomplete intracranial displacement of Mandibular asymmetry, limited mouth to the department of oral and maxillofacial the mandibular condyle without incar- opening, and occlusal disorders are the surgery of our institution. All patients or ceration. After an evaluation of the situ- main clinical features of DMCCF. These their legal guardians agreed to inclusion in ation, a timely treatment plan of closed presentations are similar to the clinical this study and provided signed informed reduction under anaesthesia was made. manifestations of unilateral condylar frac- consent. All three patients were females, Under general anaesthesia, the right ture, which may lead to early-stage mis- aged 13 years, 25 years, and 22 years. One mandibular body was held manually diagnosis and delayed treatment. Ohura patient was injured in a fall and two were and pushed downward; force was ap- 9 10 et al. and Spanio et al. reported that injured in motor vehicle accidents (MVA). plied mainly on the right lower molars. misdiagnosis and delayed treatment occur These three patients were admitted to our After several attempts, the mandible re- in about half of these patients. Panoramic hospital 1 day, 2 weeks, and 5 months after duction was achieved. The occlusion and plain radiographs cannot provide de- they had sustained their injuries. The first was recovered and then intermaxillary tailed information for diagnosis. Comput- two patients had no neurological compli- fixation was performed. Postoperative ed tomography (CT), especially coronal cations. The third patient had a serious intermaxillary traction was applied for CT, is the main diagnostic imaging meth- contusion of the brain at the time of the 1 month, and then mouth opening exer- od. More than half of patients have no injury and presented to our hospital after cises were started. The patient was fol- associated facial injuries, including neu- recovering from the contusion; this patient lowed up closely. Table 1. Basic patient information. Age, Cause of Interval between Neurological Case Gender years injury injury and treatment complications Treatment 1