- Email: [email protected]
Minimally-invasive open reduction of intracapsular condylar fractures with preoperative simulation using computer-aided design
Available online at www.sciencedirect.com
British Journal of Oral and Maxillofacial Surgery 51 (2013) e29–e33
Minimally-invasive open reduction of intracapsular condylar fractures with preoperative simulation using computer-aided design Ming-liang Yang, Bin Zhang, Qing Zhou ∗ , Xiao-bo Gao, Qiang Liu, Li Lu Department of Oral-Maxillofacial Surgery, The Affiliated Hospital of Stomatology, China Medical University, 117 Nanjing-Bei Street, Heping District, Shenyang, 110002, China Accepted 11 March 2012 Available online 3 April 2012
Abstract Reduction of intracapsular condylar fractures is difficult, so we have based our technique on preoperative simulation using computer-aided design (CAD), which has proved useful in other surgical specialties. We have treated 11 patients with intracapsular condylar fractures. Before the operation the procedure was shown on the computer using a three-dimensional simulation system. The relation between the stump and the fragment of the condyle, and assessment of the position and the size of the screw, were made preoperatively to obtain a perfect fit. The displaced fragment was reduced by elevators, and fixed with a bicortical screw through a minimised preauricular incision under general anaesthesia. The fragments and the location of the screws were similar on the preoperative simulation and on the postoperative computed tomographic (CT) scan. The reduction and fixation of the fracture showed a perfect fit on the same view in the preoperative CAD simulation in the Mimics 10.01 software and postoperatively. Postoperative clinical examinations showed good occlusion and satisfactory mouth opening. Two patients had temporary paralysis of the occipitofrontalis muscle that recovered within 3 months. All patients regained normal mandibular movements and had short and invisible scars at 6 months’ follow up. The technique of CAD simulation could help to improve the accuracy during open treatment for intracapsular condylar fractures. © 2012 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Minimally invasion; Intracapsular condylar fractures; Open reduction; CAD
Introduction Fractures of the mandibular condyle are common and account for 25–50% of all mandibular fractures.1,2 The chief symptoms of an intracapsular condylar fracture are restriction of movement and malocclusion caused by a dislocated fragment of fracture and shortened mandibular ramus. Although no consensus has been established on whether open reduction is necessary for adult patients, non-surgical treatments cannot correctly reposition the dislocated fragment of the fracture and restore the mandibular ramus to its normal length, so various surgical techniques have been developed.3–7 ∗
Corresponding author. Tel.: +86 24 22892461; fax: +86 24 22892645. E-mail address: [email protected] (Q. Zhou).
Reduction and fixation of intracapsular condylar fractures is always a challenge because it is done in such a confined space. The traditional methods for reduction and fixation are limited, so authors have explored new ways that could resolve the problem. Expansion of the incision to explore the operative field was not a good option, because there were many important anatomic structures around the temporomandibular joint (TMJ), such as branches of the facial nerve and blood vessels, and the inside of the TMJ is never seen. Recently, computer-aided design (CAD) has been used in orthognathic surgery, and plastic and reconstructive surgery.8–11 It provides an opportunity for surgeons to simulate the operation on computer before it is done on the patient. Using simulation, surgeons can obtain more information directly on the software platform. In the present study,
0266-4356/$ – see front matter © 2012 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.bjoms.2012.03.005
M.-l. Yang et al. / British Journal of Oral and Maxillofacial Surgery 51 (2013) e29–e33 Period of nerve recovery (months)
we have used CAD preoperative simulation for the open treatment of intracapsular condylar fractures and obtained satisfactory outcomes.
3 – – – – – – 3 – – –
e30
– – –
– – – – – – √
√
3.2 3.5 3 3.7 3 3.5 3.5 3.5 3.5 3 3.5 –
– √
N – √
N – – √ √
34 42 26 47 36 34 51 48 37 32 41 1 2 3 4 5 6 7 8 9 10 11
M M M M M M M M M F F
N √ √ √ √
R √ √ √ √ L √ √
Age (years) Case No
Table 1 Patients’ clinical data.
All patients were operated on under general anaesthesia. A minimised preauricular incision from the tragus to the auricular lobule was used to approach the fracture. To avoid damage to the facial nerve, the superficial temporal fascia was cut along the anterior border of the superficial temporal artery, and the branches of the facial nerve at the parotid plexus were dissected without invading the neural membrane. The facial nerve was isolated and the deep parotid was subjected to careful blunt dissection. After the capsule of the TMJ had been exposed, a T-shape incision was made. Further dissection exposed the lateral side of the condylar stump and neck. The ramus was distracted inferiorly to widen the joint space. The fractured fragment was reduced
Sex
Operative procedure
N: condylar neck fracture; S: mandibular symphyseal fracture; and P: mandibular parasymphyseal fracture. The length of the screw was measured using the AO 2.0 system.
12 12 14 12 12 12 14 12 12 12 12 9.16 8.93 10.94 9.44 8.71 9.02 11.73 8.89 9.27 8.84 10.07
Designed length of the screw (mm) Intracapsular fracture
Simultaneous mandibular fracture
Treatment Diagnosis
Practical length of the screw (mm)
6 6 7 9 10 6 6 7 8 6 9
Duration of follow up (months)
The digital imaging and communications in medicine (DICOM) files were imported into the Mimics 10.01 software (Materialize, Leuven, Belgium). Images were segmented by radiodensity and calculated into three-dimensional shapes by surface rendering on the software platform. After the three-dimensional shapes of the mandible and maxilla had been obtained, the surgical simulation was done under the guidance of the senior surgeons (Fig. 1). The craniofacial skeleton was visualised with a slice reconstruction in a threedimensional display so that the fractures could be evaluated. A single three-dimensional model of a mandible was displayed to identify the location and shape of the fragment (Fig. 2). The simulation module was used to reposition the fragment on the computer. After reduction, a cylindrical CAD shape was drawn by the MedCAD module to simulate a bicortical screw and then the cylinder CAD shape was put on to the correct place to illustrate the condylar stump and fragment fixed together. The reference data were obtained from the three-dimensional model with tools for three-dimensional measurement in the software (Fig. 3).
S – – – P – – – S – –
Preoperative simulation
Passive mouth opening (cm)
Outcome
Active mouth opening (cm)
From April to October 2010 a total of 11 patients with intracapsular condylar fractures were treated. Diagnoses were made from clinical signs and helical computed tomography (CT). All patients met the inclusion criteria: they were adult patients with unilateral or bilateral intracapsular condylar fractures, occlusal disturbance was caused by shortening of the condylar height, and the fragment of the fracture was single and big enough for fixation. The mean (range) time between the injury and the operation was 7 (5–10) days. The personal and clinical data of the patients are shown in Table 1.
4 4 3.5 4 3.5 4 4 4 4 3.5 4
Invasion of facial nerve
Patients and methods
M.-l. Yang et al. / British Journal of Oral and Maxillofacial Surgery 51 (2013) e29–e33
e31
Fig. 1. The reduction and fixation with a bicortical screw were simulated by the senior surgeons using Mimics 10.01 software, and the length of the screw can be obtained with three-dimensional measurement tools.
by two periosteal elevators, or sometimes a temporary screw.12 After the fragment had been repositioned, the point on the stump of the condyle was located from the reference data measured preoperatively on the computer. The fragment was maintained in the fixed position while the hole was drilled at the preselected point and the bicortical screw (AO 2.0 system locked bicortical screw) inserted. The screw was chosen preoperatively depending on the
surgical simulation to reduce the operating time, and it was then tightened gently to compress the gap at the fracture site. After it had been verified that the fracture was fixed with the bicortical screw, and the articular disc was correctly positioned, the capsule was carefully sutured in position and the wound closed in layers. Other simultaneous mandibular fractures were treated by rigid internal fixation (Figs. 4 and 5).
Fig. 2. The model is rotated and the location of the implants calculated.
e32
M.-l. Yang et al. / British Journal of Oral and Maxillofacial Surgery 51 (2013) e29–e33
Fig. 3. The operation was done through the approach of the minimised preauricular incision. The bicortical screw has been inserted to fix the fracture, and produced satisfactory stability.
postoperative pictures on the computer. The relation between the screw and the cortical bones was clearly shown on CT, and the sizes of the bicortical screws were suitable with no injury to the articular cartilage or surrounding tissue. The three-dimensional objects showed that the screw was in the designated position and the condyle had been replaced and fixed in the normal position. The height of the ramus on the fractured side was restored immediately postoperatively. The malocclusion was corrected and the passive mouth opening of each patient was never less than 3.5 cm. Postoperative clinical examination showed good occlusion and mouth opening of at least 3 cm in all patients. Two patients had temporary paralysis of the frontalis muscle postoperatively, but recovered gradually within 3 months. All patients regained normal mandibular movements and had short and invisible scars at 6 months’ follow-up. All patients were satisfied with the outcomes.
Discussion
Fig. 4. The coronal slice of the preoperative helical computed tomography shows that the fragment of the condylar fracture was displaced and the ramus was shortened.
Fig. 5. The coronal slice of the postoperative helical computed tomography showing that the fragment was reduced and fixed with a bicortical screw and the height of the ramus was restored.
Results A helical CT scan was done immediately after the operation. The reduction of the fragments and the location of the screws were checked on the same view in the preoperative and
The management of fractured condyles has always been controversial. Early on, the open treatment of condylar fractures meant that the fragment was used as a free bone graft. Without blood supply, infection and necrosis would cause serious complications. A period of intermaxillary fixation followed by physiotherapy was a main treatment advocated when closed treatment was used. In recent years, with the wide availability of plate and screw fixation systems, surgical treatments for intracapsular condylar fractures have attracted increasing interest. Palmieri et al. found that no benefit followed closed reduction of mandibular condylar fractures, as they were not truly reduced.13 Ellis et al. concluded that the condyle was tilted medially after conservative management.14 Worsaae and Thorn concluded that surgical was superior to non-surgical management.15 The survey initiated by Baker AW involved about 70 surgeons, most of which were from North American. And 57% of those surgeons responding to this survey favored an open approach to displaced fractures of the condylar process in adult patients indicating widespread use of such techniques.16 Although some authors considered that the dislocated fragment was associated with serious complications (including ankylosis of the TMJ)17–19 and anatomical repositioning could not be achieved in non-surgical ways, the surgical treatment was limited.3–7,17–20 Conventional internal fixation, using screws, or titanium miniplates, or both, is difficult without free grafting because the view from the lateral side of the condylar stump is confined. The data from traditional CT films are limited. However, CAD preoperative simulation supports a platform for surgeons to gain more information about the operative site. It can give them any view of the condyle on the fractured side, and provide an opportunity to evaluate the reduction and fixation of the fragment and the stump. It can even provide reference data such as the position and the angle of the hole to be drilled
M.-l. Yang et al. / British Journal of Oral and Maxillofacial Surgery 51 (2013) e29–e33
and the length of the screw. Before the operation surgeons can get a clear image of the inside view, which cannot be seen through the preauricular incision, and it can avoid unnecessary attempts to explore only the operative view. During the drilling of the hole on the stump, the condition of the fragment cannot be seen. Drilling too far could cause serious damage to the inside tissue and damage to blood vessels, and an incorrect drilling position on the fragment cannot supply sufficient stability, particularly when it is fixed with a screw. When the fragment is repositioned anatomically it will look similar to the simulation on the computer. Surgeons can operate as if in the preoperative design. This technique therefore ensures shorter operating time, fewer operational errors, more precise fit, and much better stability postoperatively. Invasion of the frontal branch of the facial nerve, which happened in the first 2 patients, was caused by excessive pull when the tension of the surrounding tissue had not been released enough, and paying more attention to the anatomy can avoid it effectively. However, the reduction and fixation of some comminuted fractures and others without obvious anatomical references, were too difficult to do surgically. Although this technique can simulate the preoperative reduction, the fixation of a comminuted fracture is still a big problem. The indication for this technique is therefore confined to unbroken fracture fragments that are big enough to be fixed, as well as having an obvious anatomical reference point. For the complexity of the operation, the experience of the surgeon is also important.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
References 1. Rowe NL, Killey HC. Fractures of the facial skeleton. 2nd ed. Edinburgh: Churchill Livingstone; 1968. p. 80–92. 2. Silvennoinen U, Iizuka T, Lindquist C, Oikarinen K. Different patterns of condylar fractures: an analysis of 382 patients in a 3-year period. J Oral Maxillofac Surg 1992;50:1032–7. 3. Loukota RA. Fixation of dicapitular fractures of the mandibular condyle with a headless bone screw. Br J Oral Maxillofac Surg 2007;45: 399–401. 4. Pilling E, Schneider M, Mai R, Loukota RA, Eckelt U. Minimally invasive fracture treatment with cannulated lag screws in intracapsular fractures of the condyle. J Oral Maxillofac Surg 2006;64:868–72. 5. Iizuka T, Lindqvist C, Hallikainen D, Mikkonen P, Paukku P. Severe bone resorption and osteoarthrosis after miniplate fixation of high condylar
17.
18.
19.
20.
e33
fractures. A clinical and radiologic study of thirteen patients. Oral Surg Oral Med Oral Pathol 1991;72:400–7. Kermer Ch, Undt G, Rasse M. Surgical reduction and fixation of intracapsular condylar fractures. A follow up study. Int J Oral Maxillofac Surg 1998;27:191–4. Huang S, Fan H, Zhang C, Zhou X, Chen P. Clinical application of lateral lag screw in fixing intracapsular saggital condylar fracture. Zhonghua Kou Qiang Yi Xue Za Zhi 2004;39:481–3 [in Chinese]. Aboul-Hosn Centenero S, Hernández-Alfaro F. 3D planning in orthognathic surgery: CAD/CAM surgical splints and prediction of the soft and hard tissues results—our experience in 16 cases. J Craniomaxillofac Surg 2012;40:162–8. Motohashi N, Kuroda T. A 3D computer-aided design system applied to diagnosis and treatment planning in orthodontics and orthognathic surgery. Eur J Orthod 1999;21:263–74. Wang G, Li J, Khadka A, Hsu Y, Li W, Hu J. CAD/CAM and rapid prototyped titanium for reconstruction of ramus defect and condylar fracture caused by mandibular reduction. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; Jun 17 [Epub ahead of print]. Li J, Hsu Y, Luo E, Khadka A, Hu J. Computer-aided design and manufacturing and rapid prototyped nanoscale hydroxyapatite/polyamide (n-HA/PA) construction for condylar defect caused by mandibular angle ostectomy. Aesthetic Plast Surg 2011;35:636–40. Meng FW, Liu YP, Hu KJ, Kong L. Use of a temporary screw for alignment and fixation of sagittal mandibular condylar fractures with lateral screws. Int J Oral Maxillofac Surg 2010;39:548–53. Palmieri C, Ellis III E, Throckmorton G. Mandibular motion after closed and open treatment of mandibular condylar process fractures. J Oral Maxillofac Surg 1999;57:764–75. Ellis III E, Palmieri C, Throckmorton G. Further displacement of condylar process fractures with closed treatment. J Oral Maxillofac Surg 1999;57:1307–17. Worsaae N, Thorn JJ. Surgical versus nonsurgical treatment of unilateral dislocated low subcondylar fractures—a clinical study of 52 cases. J Oral Maxillofac Surg 1994;52:353–61. Baker AW, McMahon J, Moos KF. Current consensus on the management of fractures of the mandibular condyle. A method by questionnaire. Int J Oral Maxillofac Surg 1998;27:258–66. Ferretti C, Bryant R, Becker P, Lawrence C. Temporomandibular joint morphology following post-traumatic ankylosis in 26 patients. Int J Oral Maxillofac Surg 2005;34:376–81. Hlawitschka M, Eckelt U. Assessment of patients treated for intracapsular fractures of the mandibular condyle by closed techniques. J Oral Maxillofac Surg 2002;60:784–92. Hlawitschka M, Loukota R, Eckelt U. Functional and radiological results of open and closed treatment of intracapsular (diacapitular) condylar fractures of the mandible. Int J Oral Maxillofac Surg 2005;34: 597–604. Davis BR, Powell JE, Morrison AD. Free-grafting of mandibular condyle fractures: clinical outcomes in 10 consecutive patients. Int J Oral Maxillofac Surg 2005;34:871–6.
British Journal of Oral and Maxillofacial Surgery 51 (2013) e29–e33
Minimally-invasive open reduction of intracapsular condylar fractures with preoperative simulation using computer-aided design Ming-liang Yang, Bin Zhang, Qing Zhou ∗ , Xiao-bo Gao, Qiang Liu, Li Lu Department of Oral-Maxillofacial Surgery, The Affiliated Hospital of Stomatology, China Medical University, 117 Nanjing-Bei Street, Heping District, Shenyang, 110002, China Accepted 11 March 2012 Available online 3 April 2012
Abstract Reduction of intracapsular condylar fractures is difficult, so we have based our technique on preoperative simulation using computer-aided design (CAD), which has proved useful in other surgical specialties. We have treated 11 patients with intracapsular condylar fractures. Before the operation the procedure was shown on the computer using a three-dimensional simulation system. The relation between the stump and the fragment of the condyle, and assessment of the position and the size of the screw, were made preoperatively to obtain a perfect fit. The displaced fragment was reduced by elevators, and fixed with a bicortical screw through a minimised preauricular incision under general anaesthesia. The fragments and the location of the screws were similar on the preoperative simulation and on the postoperative computed tomographic (CT) scan. The reduction and fixation of the fracture showed a perfect fit on the same view in the preoperative CAD simulation in the Mimics 10.01 software and postoperatively. Postoperative clinical examinations showed good occlusion and satisfactory mouth opening. Two patients had temporary paralysis of the occipitofrontalis muscle that recovered within 3 months. All patients regained normal mandibular movements and had short and invisible scars at 6 months’ follow up. The technique of CAD simulation could help to improve the accuracy during open treatment for intracapsular condylar fractures. © 2012 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Minimally invasion; Intracapsular condylar fractures; Open reduction; CAD
Introduction Fractures of the mandibular condyle are common and account for 25–50% of all mandibular fractures.1,2 The chief symptoms of an intracapsular condylar fracture are restriction of movement and malocclusion caused by a dislocated fragment of fracture and shortened mandibular ramus. Although no consensus has been established on whether open reduction is necessary for adult patients, non-surgical treatments cannot correctly reposition the dislocated fragment of the fracture and restore the mandibular ramus to its normal length, so various surgical techniques have been developed.3–7 ∗
Corresponding author. Tel.: +86 24 22892461; fax: +86 24 22892645. E-mail address: [email protected] (Q. Zhou).
Reduction and fixation of intracapsular condylar fractures is always a challenge because it is done in such a confined space. The traditional methods for reduction and fixation are limited, so authors have explored new ways that could resolve the problem. Expansion of the incision to explore the operative field was not a good option, because there were many important anatomic structures around the temporomandibular joint (TMJ), such as branches of the facial nerve and blood vessels, and the inside of the TMJ is never seen. Recently, computer-aided design (CAD) has been used in orthognathic surgery, and plastic and reconstructive surgery.8–11 It provides an opportunity for surgeons to simulate the operation on computer before it is done on the patient. Using simulation, surgeons can obtain more information directly on the software platform. In the present study,
0266-4356/$ – see front matter © 2012 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.bjoms.2012.03.005
M.-l. Yang et al. / British Journal of Oral and Maxillofacial Surgery 51 (2013) e29–e33 Period of nerve recovery (months)
we have used CAD preoperative simulation for the open treatment of intracapsular condylar fractures and obtained satisfactory outcomes.
3 – – – – – – 3 – – –
e30
– – –
– – – – – – √
√
3.2 3.5 3 3.7 3 3.5 3.5 3.5 3.5 3 3.5 –
– √
N – √
N – – √ √
34 42 26 47 36 34 51 48 37 32 41 1 2 3 4 5 6 7 8 9 10 11
M M M M M M M M M F F
N √ √ √ √
R √ √ √ √ L √ √
Age (years) Case No
Table 1 Patients’ clinical data.
All patients were operated on under general anaesthesia. A minimised preauricular incision from the tragus to the auricular lobule was used to approach the fracture. To avoid damage to the facial nerve, the superficial temporal fascia was cut along the anterior border of the superficial temporal artery, and the branches of the facial nerve at the parotid plexus were dissected without invading the neural membrane. The facial nerve was isolated and the deep parotid was subjected to careful blunt dissection. After the capsule of the TMJ had been exposed, a T-shape incision was made. Further dissection exposed the lateral side of the condylar stump and neck. The ramus was distracted inferiorly to widen the joint space. The fractured fragment was reduced
Sex
Operative procedure
N: condylar neck fracture; S: mandibular symphyseal fracture; and P: mandibular parasymphyseal fracture. The length of the screw was measured using the AO 2.0 system.
12 12 14 12 12 12 14 12 12 12 12 9.16 8.93 10.94 9.44 8.71 9.02 11.73 8.89 9.27 8.84 10.07
Designed length of the screw (mm) Intracapsular fracture
Simultaneous mandibular fracture
Treatment Diagnosis
Practical length of the screw (mm)
6 6 7 9 10 6 6 7 8 6 9
Duration of follow up (months)
The digital imaging and communications in medicine (DICOM) files were imported into the Mimics 10.01 software (Materialize, Leuven, Belgium). Images were segmented by radiodensity and calculated into three-dimensional shapes by surface rendering on the software platform. After the three-dimensional shapes of the mandible and maxilla had been obtained, the surgical simulation was done under the guidance of the senior surgeons (Fig. 1). The craniofacial skeleton was visualised with a slice reconstruction in a threedimensional display so that the fractures could be evaluated. A single three-dimensional model of a mandible was displayed to identify the location and shape of the fragment (Fig. 2). The simulation module was used to reposition the fragment on the computer. After reduction, a cylindrical CAD shape was drawn by the MedCAD module to simulate a bicortical screw and then the cylinder CAD shape was put on to the correct place to illustrate the condylar stump and fragment fixed together. The reference data were obtained from the three-dimensional model with tools for three-dimensional measurement in the software (Fig. 3).
S – – – P – – – S – –
Preoperative simulation
Passive mouth opening (cm)
Outcome
Active mouth opening (cm)
From April to October 2010 a total of 11 patients with intracapsular condylar fractures were treated. Diagnoses were made from clinical signs and helical computed tomography (CT). All patients met the inclusion criteria: they were adult patients with unilateral or bilateral intracapsular condylar fractures, occlusal disturbance was caused by shortening of the condylar height, and the fragment of the fracture was single and big enough for fixation. The mean (range) time between the injury and the operation was 7 (5–10) days. The personal and clinical data of the patients are shown in Table 1.
4 4 3.5 4 3.5 4 4 4 4 3.5 4
Invasion of facial nerve
Patients and methods
M.-l. Yang et al. / British Journal of Oral and Maxillofacial Surgery 51 (2013) e29–e33
e31
Fig. 1. The reduction and fixation with a bicortical screw were simulated by the senior surgeons using Mimics 10.01 software, and the length of the screw can be obtained with three-dimensional measurement tools.
by two periosteal elevators, or sometimes a temporary screw.12 After the fragment had been repositioned, the point on the stump of the condyle was located from the reference data measured preoperatively on the computer. The fragment was maintained in the fixed position while the hole was drilled at the preselected point and the bicortical screw (AO 2.0 system locked bicortical screw) inserted. The screw was chosen preoperatively depending on the
surgical simulation to reduce the operating time, and it was then tightened gently to compress the gap at the fracture site. After it had been verified that the fracture was fixed with the bicortical screw, and the articular disc was correctly positioned, the capsule was carefully sutured in position and the wound closed in layers. Other simultaneous mandibular fractures were treated by rigid internal fixation (Figs. 4 and 5).
Fig. 2. The model is rotated and the location of the implants calculated.
e32
M.-l. Yang et al. / British Journal of Oral and Maxillofacial Surgery 51 (2013) e29–e33
Fig. 3. The operation was done through the approach of the minimised preauricular incision. The bicortical screw has been inserted to fix the fracture, and produced satisfactory stability.
postoperative pictures on the computer. The relation between the screw and the cortical bones was clearly shown on CT, and the sizes of the bicortical screws were suitable with no injury to the articular cartilage or surrounding tissue. The three-dimensional objects showed that the screw was in the designated position and the condyle had been replaced and fixed in the normal position. The height of the ramus on the fractured side was restored immediately postoperatively. The malocclusion was corrected and the passive mouth opening of each patient was never less than 3.5 cm. Postoperative clinical examination showed good occlusion and mouth opening of at least 3 cm in all patients. Two patients had temporary paralysis of the frontalis muscle postoperatively, but recovered gradually within 3 months. All patients regained normal mandibular movements and had short and invisible scars at 6 months’ follow-up. All patients were satisfied with the outcomes.
Discussion
Fig. 4. The coronal slice of the preoperative helical computed tomography shows that the fragment of the condylar fracture was displaced and the ramus was shortened.
Fig. 5. The coronal slice of the postoperative helical computed tomography showing that the fragment was reduced and fixed with a bicortical screw and the height of the ramus was restored.
Results A helical CT scan was done immediately after the operation. The reduction of the fragments and the location of the screws were checked on the same view in the preoperative and
The management of fractured condyles has always been controversial. Early on, the open treatment of condylar fractures meant that the fragment was used as a free bone graft. Without blood supply, infection and necrosis would cause serious complications. A period of intermaxillary fixation followed by physiotherapy was a main treatment advocated when closed treatment was used. In recent years, with the wide availability of plate and screw fixation systems, surgical treatments for intracapsular condylar fractures have attracted increasing interest. Palmieri et al. found that no benefit followed closed reduction of mandibular condylar fractures, as they were not truly reduced.13 Ellis et al. concluded that the condyle was tilted medially after conservative management.14 Worsaae and Thorn concluded that surgical was superior to non-surgical management.15 The survey initiated by Baker AW involved about 70 surgeons, most of which were from North American. And 57% of those surgeons responding to this survey favored an open approach to displaced fractures of the condylar process in adult patients indicating widespread use of such techniques.16 Although some authors considered that the dislocated fragment was associated with serious complications (including ankylosis of the TMJ)17–19 and anatomical repositioning could not be achieved in non-surgical ways, the surgical treatment was limited.3–7,17–20 Conventional internal fixation, using screws, or titanium miniplates, or both, is difficult without free grafting because the view from the lateral side of the condylar stump is confined. The data from traditional CT films are limited. However, CAD preoperative simulation supports a platform for surgeons to gain more information about the operative site. It can give them any view of the condyle on the fractured side, and provide an opportunity to evaluate the reduction and fixation of the fragment and the stump. It can even provide reference data such as the position and the angle of the hole to be drilled
M.-l. Yang et al. / British Journal of Oral and Maxillofacial Surgery 51 (2013) e29–e33
and the length of the screw. Before the operation surgeons can get a clear image of the inside view, which cannot be seen through the preauricular incision, and it can avoid unnecessary attempts to explore only the operative view. During the drilling of the hole on the stump, the condition of the fragment cannot be seen. Drilling too far could cause serious damage to the inside tissue and damage to blood vessels, and an incorrect drilling position on the fragment cannot supply sufficient stability, particularly when it is fixed with a screw. When the fragment is repositioned anatomically it will look similar to the simulation on the computer. Surgeons can operate as if in the preoperative design. This technique therefore ensures shorter operating time, fewer operational errors, more precise fit, and much better stability postoperatively. Invasion of the frontal branch of the facial nerve, which happened in the first 2 patients, was caused by excessive pull when the tension of the surrounding tissue had not been released enough, and paying more attention to the anatomy can avoid it effectively. However, the reduction and fixation of some comminuted fractures and others without obvious anatomical references, were too difficult to do surgically. Although this technique can simulate the preoperative reduction, the fixation of a comminuted fracture is still a big problem. The indication for this technique is therefore confined to unbroken fracture fragments that are big enough to be fixed, as well as having an obvious anatomical reference point. For the complexity of the operation, the experience of the surgeon is also important.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
References 1. Rowe NL, Killey HC. Fractures of the facial skeleton. 2nd ed. Edinburgh: Churchill Livingstone; 1968. p. 80–92. 2. Silvennoinen U, Iizuka T, Lindquist C, Oikarinen K. Different patterns of condylar fractures: an analysis of 382 patients in a 3-year period. J Oral Maxillofac Surg 1992;50:1032–7. 3. Loukota RA. Fixation of dicapitular fractures of the mandibular condyle with a headless bone screw. Br J Oral Maxillofac Surg 2007;45: 399–401. 4. Pilling E, Schneider M, Mai R, Loukota RA, Eckelt U. Minimally invasive fracture treatment with cannulated lag screws in intracapsular fractures of the condyle. J Oral Maxillofac Surg 2006;64:868–72. 5. Iizuka T, Lindqvist C, Hallikainen D, Mikkonen P, Paukku P. Severe bone resorption and osteoarthrosis after miniplate fixation of high condylar
17.
18.
19.
20.
e33
fractures. A clinical and radiologic study of thirteen patients. Oral Surg Oral Med Oral Pathol 1991;72:400–7. Kermer Ch, Undt G, Rasse M. Surgical reduction and fixation of intracapsular condylar fractures. A follow up study. Int J Oral Maxillofac Surg 1998;27:191–4. Huang S, Fan H, Zhang C, Zhou X, Chen P. Clinical application of lateral lag screw in fixing intracapsular saggital condylar fracture. Zhonghua Kou Qiang Yi Xue Za Zhi 2004;39:481–3 [in Chinese]. Aboul-Hosn Centenero S, Hernández-Alfaro F. 3D planning in orthognathic surgery: CAD/CAM surgical splints and prediction of the soft and hard tissues results—our experience in 16 cases. J Craniomaxillofac Surg 2012;40:162–8. Motohashi N, Kuroda T. A 3D computer-aided design system applied to diagnosis and treatment planning in orthodontics and orthognathic surgery. Eur J Orthod 1999;21:263–74. Wang G, Li J, Khadka A, Hsu Y, Li W, Hu J. CAD/CAM and rapid prototyped titanium for reconstruction of ramus defect and condylar fracture caused by mandibular reduction. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; Jun 17 [Epub ahead of print]. Li J, Hsu Y, Luo E, Khadka A, Hu J. Computer-aided design and manufacturing and rapid prototyped nanoscale hydroxyapatite/polyamide (n-HA/PA) construction for condylar defect caused by mandibular angle ostectomy. Aesthetic Plast Surg 2011;35:636–40. Meng FW, Liu YP, Hu KJ, Kong L. Use of a temporary screw for alignment and fixation of sagittal mandibular condylar fractures with lateral screws. Int J Oral Maxillofac Surg 2010;39:548–53. Palmieri C, Ellis III E, Throckmorton G. Mandibular motion after closed and open treatment of mandibular condylar process fractures. J Oral Maxillofac Surg 1999;57:764–75. Ellis III E, Palmieri C, Throckmorton G. Further displacement of condylar process fractures with closed treatment. J Oral Maxillofac Surg 1999;57:1307–17. Worsaae N, Thorn JJ. Surgical versus nonsurgical treatment of unilateral dislocated low subcondylar fractures—a clinical study of 52 cases. J Oral Maxillofac Surg 1994;52:353–61. Baker AW, McMahon J, Moos KF. Current consensus on the management of fractures of the mandibular condyle. A method by questionnaire. Int J Oral Maxillofac Surg 1998;27:258–66. Ferretti C, Bryant R, Becker P, Lawrence C. Temporomandibular joint morphology following post-traumatic ankylosis in 26 patients. Int J Oral Maxillofac Surg 2005;34:376–81. Hlawitschka M, Eckelt U. Assessment of patients treated for intracapsular fractures of the mandibular condyle by closed techniques. J Oral Maxillofac Surg 2002;60:784–92. Hlawitschka M, Loukota R, Eckelt U. Functional and radiological results of open and closed treatment of intracapsular (diacapitular) condylar fractures of the mandible. Int J Oral Maxillofac Surg 2005;34: 597–604. Davis BR, Powell JE, Morrison AD. Free-grafting of mandibular condyle fractures: clinical outcomes in 10 consecutive patients. Int J Oral Maxillofac Surg 2005;34:871–6.