Five-Year Experience with the Transoral Endoscopically Assisted Treatment of Displaced Condylar Mandible Fractures

Five-Year Experience with the Transoral Endoscopically Assisted Treatment of Displaced Condylar Mandible Fractures Ralf Schön, M.D., D.M.D., Otto Fakler, M.D., D.M.D., Nils-Claudius Gellrich, M.D., D.M.D., and Rainer Schmelzeisen, M.D., D.M.D. Freiburg, Germany Background: From April of 1998 to May of 2003, the minimally invasive transoral approach for endoscopically assisted reduction and osteosynthesis of 62 displaced condylar mandible fractures was performed in 58 patients. Methods: By means of limited transoral incision, the endoscopically assisted reduction and fixation of condylar fractures was performed using 30- and 45-degree angled endoscopes. Twenty-five fractures were condylar and 37 were subcondylar. The condylar neck of the proximal fragment was displaced medially in 17 fractures and laterally in 45 fractures. Four patients presented bilateral condylar mandible fractures. Using angled endoscopes, good visibility of the fracture site was obtained, which allowed for precise anatomical reduction in all patients. An angulated drill and screwdriver facilitated miniplate fixation by means of the transoral approach. The mean operating time was measured in the last 30 consecutive cases: 1 hour 5 minutes. Results: Postoperatively, all patients showed quick recovery to preinjury occlusion. Normal temporomandibular joint function was noted 6 months after surgery in all patients. Conclusions: The transoral endoscopically assisted treatment using an angulated drill and screwdriver is the method of choice for surgical management of displaced condylar fractures, even in fractures with medial override. Facial nerve injury and visible scars are avoided by using the transoral approach. (Plast. Reconstr. Surg. 116: 44, 2005.) Fractures of the mandibular condyle are common and account for 9 to 45 percent of all mandibular fractures. 1,2 Because of possible complications such as risk of facial nerve injury and creation of visible scars, the indication for surgical reduction or nonsurgical treatment remains controversial, and closed reduction is still the most widely used method. 3 7 Superior functional results following anatomical reduction compared with nonsurgical treatment are reported for displaced fractures. 5,7 9 The transoral approach for reduction of condylar mandible fractures has been described to reduce the risk of facial nerve injury without visible scars. 10 13 However, because of limited visibility of the fracture site, this technique has not gained wide acceptance. Using an endoscopically assisted technique for transoral surgical reduction of condyle fractures, excellent visibility can be achieved through limited incisions. 13 15 Initially, transoral endoscopically assisted treatment was only recommended for laterally displaced subcondylar fractures. 13,16,17 After satisfying initial results and experience with this technically demanding method, we From the Department of Oral and Maxillofacial Surgery, University Hospital. Received for publication October 21, 2003; revised January 12, 2004. DOI: 10.1097/01.PRS.0000169690.78547.0C 44

Vol. 116, No. 1 / DISPLACED CONDYLAR MANDIBLE FRACTURES 45 have been using the transoral endoscopically assisted approach routinely also for the treatment of displaced condylar fractures with medial override for 5 years. 14,15 Refinements of the minimally invasive transoral technique for the treatment of condylar fractures and postoperative results are demonstrated. PATIENTS AND METHODS From April of 1998 to May of 2003, the transoral approach for endoscopically assisted reduction and osteosynthesis of 62 displaced condylar mandible fractures was performed in 58 patients using an angulated drill and screwdriver (Stryker Howmedica, Leibinger, Mühlheim a.d. Ruhr, Germany). Forty-two patients were male patients and 16 were female patients, with an average age of 28 years. Only dislocated condylar fractures in patients with malocclusion and functional impairment such as open-bite deformity and malocclusion caused by shortening of the mandibular ramal height were treated surgically. Nonsurgical treatment was performed in the majority of pediatric patients and in all patients who presented fractures without functional disturbances or nondisplaced condylar fractures. Surgical treatment was only performed when at least two screws could be anchored in the condylar fragment. High condylar fractures such as intracapsular and condylar head fractures were treated nonsurgically. The type of fracture, degree of displacement, and result of reduction were evaluated intraoperatively with the endoscope, preoperatively and postoperatively, by Townes and panoramic radiographs and in selected cases by computed tomography (Figs. 1 through 6). Twenty-five fractures were condylar and 37 fractures were subcondylar; the condylar neck of the proximal fragment was displaced medially in 17 fractures and laterally in 45 fractures (Fig. 6, above, left). In four patients, bilateral condylar mandible fractures were treated by means of the transoral approach (Figs. 3 through 6). Additional mandibular fractures were treated in 21 patients by transoral osteosynthesis. Using 30-degree and 45-degree angled endoscopes and a xenon light source (Karl Storz, Tuttlingen, Germany), the endoscopically assisted reduction and fixation of displaced condylar fractures was performed by means of a limited transoral incision 15,16 (Fig. 6). Six months after surgery, the function of the mandible and temporomandibular joint was evaluated by measurements of maximal incisal opening, deviation on mouth opening, the degree of lateral excursion, and the presence of temporomandibular joint pain. Surgical Technique The transoral incision was lined out along the anterior aspect of the ascending mandibular ramus. Subperiosteal preparation without damaging the masseter muscle and preoperative infiltration of local anesthesia were performed to avoid bleeding in the optical cavity. 13 15 Mandibulomaxillary fixation was not performed intraoperatively to allow retrieval and repositioning of the condylar fragment by distraction of the temporomandibular joint region. Pressure was applied manually onto the posterior teeth of the mandible and the mandible was rotated forward to distract the temporomandibular joint region. In condylar fractures with medial override, the condylar neck was first reduced into a lateral position. This procedure can be facilitated by inserting an elevator subperiosteally at the lingual aspect of the ascending ramus to push the fragment into a lateral position during distraction of the temporomandibular joint region. When the elevator is carefully inserted subperiosteally cranial to the mandibular foramen, damage of the mandibular nerve and branches of the maxillary artery is avoided. Using an angulated screwdriver with a plate screw-holding device (Stryker Howmedica), the insertion of the first screw together with a 2.0 AO/ASIF noncompression miniplate (Synthes, Paoli, Pa.) was performed in the proximal fragment 13,15 (Fig. 6, above, right). The fracture was then reduced by pulling the plate caudally using a modified nerve hook inserted into an empty screw hole. After endoscopic control of the fracture reduction, the second screw was inserted in the ascending ramus of the mandible. Occlusion was controlled to ensure that the condylar head was located in the glenoid fossa following distraction of the temporomandibular joint region and fracture fixation. When preinjury occlusion and anatomical reduction were obtained, osteosynthesis was completed. Two miniplates are recommended to allow for adequate fixation in this mechanically demanding area. When there is sufficient bone surface that two miniplates can be placed in the condylar and subcondylar areas, the first miniplate is preferably placed at the cranial

46 PLASTIC AND RECONSTRUCTIVE SURGERY, July 2005 FIG. 1. Townes radiographs obtained preoperatively (left) and postoperatively (right) demonstrate a medially displaced condylar fracture before and after minimally invasive transoral anatomical reduction and osteosynthesis. Maxillomandibular fixation was used intraoperatively for the osteosynthesis of an additional mandibular fracture. FIG. 2. Same patient as shown in Figure 1. Panoramic radiographs obtained preoperatively (above) and postoperatively (below) demonstrate a medially displaced condylar fracture before and after minimally invasive transoral anatomical reduction and osteosynthesis. Maxillomandibular fixation was used intraoperatively for the osteosynthesis of an additional mandibular fracture.

Vol. 116, No. 1 / DISPLACED CONDYLAR MANDIBLE FRACTURES 47 FIG. 3. Computed tomographic scan, coronal view, shows bilateral displaced condylar neck fracture. aspect of the fracture using screws 4 mm in length (Fig. 6, above, right, and below, left). After placement of the first plate in the cranial aspect of the fracture, the visibility of the fracture site, especially at the posterior aspect of the ascending ramus, was superior compared with the placement of the first plate at the posterior aspect of the ascending ramus. The exact reduction and fixation at the posterior aspect of the ascending ramus was facilitated following the initial fixation of the fracture with one plate at the cranial aspect. The precise placement of the posterior plate in the area with an increased thickness of cortical bone is most important to allow for secure anchorage of the plate and a functional, stable fixation. Exact control of the anatomical reduction and fixation was achieved intraoperatively by endoscopic means (Fig. 6, below, left and right). Preferably, a 2.0 AO/ASIF noncompression miniplate (modified zygoma plate; Synthes, no. 443.451) and screws 6 mm in length were used for osteosynthesis in this mechanically demanding area 15,18 (Figs. 1, right,2,below,4,right, 5, and 6, below, left). Precise bending of the plates was not always possible in this area, and the use of those less rigid plates compared with 2.0 mandible plates (Synthes) may be advantageous. 18 More rigid plates may cause dislocation of the fracture when tightening the screws when precise bending cannot be performed. The 2.0 compact four-hole plates with space were used as our second choice, using twoplate fixation when there was not sufficient room for placement of a modified zygoma plate (Figs. 4, 5, and 6, below, left and right). RESULTS Osteosynthesis was performed in all patients by the transoral approach only. 17 Good visualization by endoscopic means allowed for precise control of reduction and fixation. The angulated drill and screwdriver facilitated transoral osteosynthesis. The insertion of the first screw together with the plate proved to be helpful. 13 15 Two 2.0 AO-ASIF miniplates (Synthes) were placed in 34 of 62 fractures. Postoperatively, the position of the condylar fragment was confirmed by panoramic and Townes radiographs (Figs. 1, right, 2, below, and 4, right, 5). Anatomical reduction and restoration of the vertical height of the ascending mandibular ramus without malocclusion was achieved in all patients. The mean operating time was 1 hour 5 minutes for the minimally invasive transoral treatment of condylar fractures measured in the last 30 consecutive cases. Immediate postoperative movement was achieved in all patients, and a soft diet was maintained for 10 days after surgery. After 6 months, none of the patients presented postoperative malocclusion, and mouth opening in all patients was more than 40 mm, without deviation on opening. Lateral excursion was not limited and there were no signs of temporomandibular joint dysfunction. 15 In two patients, removal of the osteosynthesis material was indicated because of plate fracture after 4 months in one patient and screw loosening 12 months postoperatively in another patient (Fig. 5). Uneventful healing and good temporomandibular joint function were noted in both patients. In one patient with a dislocated condylar fracture with medial override, the fragment could not be retrieved intraoperatively. The patient was then treated by mandibulomaxillary fixation for 7 days. Functional treatment using an orthodontic appliance such as an activator was performed. 19 Good temporomandibular joint function without malocclusion was achieved after 12 months of activator treatment. DISCUSSION Nonsurgical treatment of condylar mandible fractures is most widely performed. Open-bite deformity or malocclusion may occur following nonsurgical treatment because of shortening of the ascending ramus. 8,14,15,20 To avoid these complications in displaced fractures, open reduction for anatomical reduction is recommended. 4,5,7 9,21 The indication for surgical reduction versus nonsurgical treatment of displaced condylar fractures remains controversial in maxillofacial surgery because of pos-

48 PLASTIC AND RECONSTRUCTIVE SURGERY, July 2005 FIG. 4. Townes radiographs obtained immediately postoperatively (left) and 1 year after surgery (right) demonstrate the bilateral displaced condylar fractures before and after transoral anatomical reduction and osteosynthesis (same patient as shown in Fig. 3). FIG. 5. Panoramic radiograph obtained 1 year after surgery demonstrates the bilateral displaced condylar fractures after transoral anatomical reduction and osteosynthesis (same patient as in Fig. 3). Note loosening of one screw in the right condylar area. Maxillomandibular fixation was performed at the time of admission for treatment of the additional mandibular fracture and for stabilization of the traumatized teeth. The surgical treatment of the condylar fractures had to be delayed by 7 days because of additional injuries. sible complications such as damage of the facial nerve and creation of visible scars when surgical treatment is performed. 4,5 8 To minimize the risk of the described complications, endoscopically assisted techniques using limited extraoral or transoral incisions have been described for various indications in the craniomaxillofacial area. 22 25 The extraoral approach for endoscopically assisted treatment of condylar fractures has previously been described by the authors as the preferred approach for fractures with medial displacement of the condylar head, for condylar fractures with medial override, and for comminuted condylar fractures. The transoral approach was recommended only for fractures with a laterally displaced condylar neck. 13 After the first promising results, the authors have been routinely using the transoral approach for displaced and dislocated condylar fractures even those with medial override for 5 years. High condylar neck fractures have been treated by the same approach, when at least two screws could be anchored in the condylar fragment. 14,17 Special instruments such as reduction forceps, angled elevators, long periosteal elevators, and modified nerve hooks have been used to facilitate the fracture reductions and osteosynthesis (Synthes and AO Development Institute, Davos, Switzerland). 13,15,17 Using the endoscopically assisted technique, precise intraoperative quality control of the fracture reduction is performed, as the exact anatomical reduction is important for preventing failure of the osteosynthesis, such as screw loosening and plate fracture, in this mechanically demanding area. 18 The transoral treatment proved to be a reliable surgical technique also for the treatment of displaced subcondylar or condylar neck fractures, even those with medial override. Good functional results 18 months after minimally invasive treatment of displaced condylar fractures were demonstrated previously. 17 A steep learning curve with significant reduction of operating time was noted when using the endoscopically assisted technique routinely. 13 15,17 In nondislocated fractures, intracapsular fractures of the condylar head, and condylar fractures without functional disturbances, nonsurgical treatment remains the treatment of choice. A close follow-up and functional treatment using orthodontic appliances such as an activator treatment is recommended for rehabilitation. 19 Satisfying functional results can be achieved using an activator for nonsurgical treatment even in severely dislocated condylar

Vol. 116, No. 1 / DISPLACED CONDYLAR MANDIBLE FRACTURES 49 FIG. 6. Endoscopic view of the left dislocated condylar fracture (same patient as in Figs. 3 through 5) after exposure of the fracture site (above, left) and following plate fixation at the cranial aspect of the fracture with one screw in the condylar fragment. (Above, right) The fracture was reduced by pulling the plate caudally, and fixation was performed with only two screws at the cranial aspect. The result of fracture reduction is controlled endoscopically before the second plate is placed parallel to the posterior aspect of the ascending mandibular ramus. (Below, left) Anatomical reduction of the fracture and placement of the second plate parallel to the posterior border of the ascending mandibular ramus are controlled endoscopically. (Below, right) Note the precise fracture reduction at the posterior aspect of ascending the mandibular ramus. fractures. However, compared with an open treatment with anatomical reduction, a prolonged postoperative functional treatment of up to 12 months may be needed to obtain satisfying and stable results. After nonsurgical treatment of severely displaced condylar fractures, long-term complications such as clicking and chronic pain in the temporomandibular joint area may occur because of distorted condylar morphology, with limitations in mobility of the condyle. 8,13,17 Compensatory hypermobility with habitual luxation of the contralateral joint may also cause chronic pain and unsatisfying functional long-term results. 14 The major advantage of open treatment of dislocated condylar fractures is the exact anatomical reduction and osteosynthesis to allow for immediate postoperative function. 4,5,8,20 Using the endoscopically assisted minimally invasive transoral technique, good visibility of the fracture site and precise intraoperative control after fixation were obtained. Anatomical fracture reduction may also lead to repositioning of the traumatized attached soft tissues in the temporomandibular joint area, such as the articulation disk and capsula, the ligaments, and the lateral pterygoideus muscle. This may increase the chance of undisturbed long-term temporomandibular joint function. 21 A retrospective long-term study to evaluate the effect of surgical and nonsurgical treatment of severely displaced condylar fractures concerning the soft tissues in the vicinity of the joint is in progress.

50 PLASTIC AND RECONSTRUCTIVE SURGERY, July 2005 CONCLUSIONS The transoral endoscopically assisted treatment using an angulated drill and screwdriver is the method of choice for surgical management of displaced condylar fractures, even in fractures with medial override. Facial nerve injury and visible scars are avoided using this minimally invasive technique. Intensive training in endoscopic techniques is mandatory before the endoscopically assisted transoral treatment of condylar fractures can be performed. Ralf Schön, M.D., D.M.D. Klinik und Poliklinik für Mund-, Kiefer- und Gesichtschirurgie Universitätsklinik Freiburg Hugstetter Str. 55 D-79106 Freiburg i. Br., Germany schoen@zmk2.ukl.uni-freiburg.de REFERENCES 1. Tasanen, A., and Lamberg, M. A. Transosseous wiring in the treatment of condylar fractures of the mandible. J. Maxillofac. Surg. 4: 200, 1976. 2. Schön, R., Roveda, S. I. L., and Carter, B. Mandibular fractures in Townsville, Australia: Incidence, etiology and treatment using the 2.0 AO/ASIF Miniplate system. Br. J. Oral Maxillofac. Surg. 39: 145, 2001. 3. Walker, R. V. Condylar fractures: Nonsurgical management. J. Oral Maxillofac. Surg. 52: 1185, 1994. 4. Ellis, E., III, and Dean, J. Rigid fixation of mandibular condyle fractures. Oral Surg. Oral Med. Oral Pathol. 76: 6, 1993. 5. Zide, M. F., and Kent, J. N. Indications for open reduction of mandibular condyle fractures. Oral Maxillofac. Surg. 41: 89, 1983. 6. Weinberg, M. J., Merx, P., Antonymshyn, O., and Farb, R. Facial nerve palsy after mandibular fractures. Ann. Plast. Surg. 34: 546, 1995. 7. Hall, M. B. Condylar fractures: Surgical management. J. Oral Maxillofac. Surg. 52: 1189, 1994. 8. Ellis, E., III, Simon, P., and Throckmorton, G. S. Occlusal results after open or closed treatment of fractures of the mandibular condylar process. Int. J. Oral Maxillofac. Surg. 58: 260, 2000. 9. Widmark, G., Bagenholm, T., Kahnberg, K. E., and Lindahl, L. Open reduction of subcondylar fractures. Int. J. Oral Maxillofac. Surg. 25: 107, 1996. 10. Silverman, S. A new operation for displaced fractures at the neck of the mandibular condyle. Dental Cosmos. 67: 876, 1925. 11. Steinhäuser, E. W. Eingriffe am Processus articulaaris auf dem oralen Weg. Dtsch. Zahnärztl. Z. 19: 694, 1964. 12. Fritzemeier, C. U., and Bechthold, H. Die Osteosynthese von Unterkiefergelenkfortsatzfrakturen mit alleinigem Zugang von intraoral. Dtsch. Z. Mund. Kiefer Gesichtschir. 17: 66, 1993. 13. Schön, R., Gutwald, R., Schramm, A., Gellrich, N.-C., and Schmelzeisen, R. Endoscopic assisted treatment of condylar fractures: Extraoral versus intraoral approach. Int. J. Oral Maxillofac. Surg. 31: 237, 2002. 14. Schön, R., Gellrich, N. C., and Schmelzeisen, R. Frontiers in maxillofacial endoscopic surgery. Atlas Oral Maxillofac. Surg. Clin. North Am. 11: 209, 2003. 15. Schön, R., and Schmelzeisen, R. Endoscopic fracture treatment. Ann. R. Australas. Coll. Dent. Surg. 16: 40, 2002. 16. Chen, C.-T., Lai, J.-P., Tung, T.-C., and Chen, Y.-R. Endoscopically assisted mandibular subcondylar fracture repair. Plast. Reconstr. Surg. 103: 160, 1998. 17. Schön, R., Schramm, A., Gellrich, N.-C., and Schmelzeisen, R. Follow up 18 months after transoral endoscopic assisted treatment of condylar fractures. J. Oral Maxillofac. Surg. 61: 49, 2003. 18. Haug, R. H., Gilman, P. P., and Goltz, M. A biomechanical evaluation of mandibular condyle fracture plating technique. J. Oral Maxillofac. Surg. 60: 73, 2002. 19. Basdra, E. K., Stellzig, A., and Komposch, G. Functional treatment of condylar fractures in adult patients. Am. J. Orthod. Dentofacial Orthop. 113: 641, 1998. 20. Dahlstrom, L., Kahnberg, K. E., and Lindahl, L. 5 years follow-up on condylar fractures. Int. J. Oral Maxillofac. Surg. 18: 18, 1989. 21. Umstadt, H. E., Ellers, M., Müller, H.-H., and Austermann, K. H. Functional reconstruction of the TM joint of severely displaced fractures and fracture dislocation. J. Craniomaxillofac. Surg. 28: 97, 2000. 22. Vasconez, L. O., Core, G. B., and Oslin, B. Endoscopy in plastic surgery: An overview. Clin. Plast. Surg. 22: 585, 1995. 23. Schön, R., Gellrich, N.-C., Schramm, A., and Schmelzeisen, R. Endoskopische Chirurgie im Mund-, Kiefer- und Gesichtsbereich: Videodemonstration einer endoskopisch assistierten Versorgung einer dislozierten Jochbeinfraktur. J. D.G.P.W. 12:12, 2000. 24. Graham, H. D., and Spring, P. Endoscopic repair of frontal sinus fracture: Case report. J. Craniomaxillofac. Trauma 2: 52, 1996. 25. Jacobovicz, J., Lee, C., and Trabulsky, P. P. Endoscopic repair of mandibular subcondylar fracture. Plast. Reconstr. Surg. 101: 160, 1998.