CLINICAL STUDY
Endoscope-Assisted Conservative Condylectomy Combined With Orthognathic Surgery in the Treatment of Mandibular Condylar Osteochondroma Hongbo Yu, DDS, MD,* Feifei Jiao, MB,† Biao Li, DDS,* Lei Zhang, DDS, MD,* Steve Guofang Shen, DDS, MD,* and Xudong Wang, DDS, MD*
Abstract: Mandibular condylar osteochondroma (OC) results in asymmetric prognathism with facial morphologic and functional disturbance. The aim of this study was to explore the feasibility of endoscope-assisted conservative condylectomy combined with simultaneous orthognathic surgery in the treatment of condylar OC. Thirteen patients with OC of the mandibular condyle were enrolled in this study. With the aid of endoscope, condylar OC resection and conservative condylectomy were carried out via intraoral approach. A direct vision of the magnified and illuminated operative field was realized. Simultaneous orthognathic surgery was used to correct facial asymmetry and malocclusion. All patients healed uneventfully. No facial nerve injury and salivary fistula occurred. Facial symmetry and morphology were greatly improved, and stable occlusion was obtained in all cases. The patients showed no signs of recurrence and temporomandibular joint ankylosis in the 16 to 54 months of follow-up. Endoscope-assisted tumor resection and condylectomy combined with simultaneous orthognathic surgery provide us a valuable option in the treatment of mandibular condylar OC. Key Words: Condylar osteochondroma, endoscope, conservative condylectomy, orthognathic surgery, asymmetric prognathism (J Craniofac Surg 2014;25: 1379–1382)
From the *Department of Oral and Craniomaxillofacial Science, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, People’s Republic of China; and †China-Japan Friendship Dental Clinic, Shanghai Stomatological Disease Center, Shanghai, People’s Republic of China. Received October 5, 2013. Accepted for publication February 8, 2014. Address correspondence and reprint requests to Xudong Wang, DDS, MD, and Steve Guofang Shen, DDS, MD, Department of Oral and Craniomaxillofacial Science, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, 200011, Shanghai, People’s Republic of China; E-mail: [email protected] Hongbo Yu and Feifei Jiao contributed equally to this study. Steve Guofang Shen and Xudong Wang are co–corresponding authors. Supported by grant 81101131 from the National Natural Science Foundation of China and combined Medicine and Engineering Project of Shanghai Jiao Tong University (YG2013MS56). The authors report no conflicts of interest. Copyright © 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000000862
O
steochondroma (OC), also known as osteocartilaginous exostosis, is one of the most common benign tumors of long bones but is rarely found in facial skeleton. However, mandibular condylar OC can result in morphologic and functional disturbance, including facial asymmetry, malocclusion, and temporomandibular joint (TMJ) dysfunction.1,2 Therefore, the treatment of condylar OC should include not only surgical excision of the lesion but also the correction of dentomaxillofacial deformities.3,4 At present, condylar OC resection and condylectomy combined with orthognathic surgery are a proposed option for the treatment of condylar OC.1,5 For condylectomy, the preauricular approach, either on its own or in combination with cervical incisions, is the most popular used. However, the conventional resection has a risk for facial nerve injury and sometimes leaves a prominent scar on the face.6 Endoscopic surgery has been used more frequently in the head and neck area since the end of the 1990s.7,8 Recently, there were a few reports of its application in the treatment of TMJ ankylosis, condylectomy, and condylar reconstruction.9–11 For the reason that endoscope has advantages including small incisions, minor tissue damage, and direct vision of a magnified and illuminated operative field, we tried its application in the treatment of condylar OC. To correct facial asymmetry and malocclusion, orthognathic surgery is an essential option.1 In different situations, mandibular sagittal split ramus osteotomies (SSROs), Le Fort I maxillary osteotomies, genioplasties, and lower border osteotomies might be required.12 For the reason that the secondary deformities are complex and variable, individualized preoperative surgical planning is indispensable. In this study, endoscope-assisted condylar OC resection combined with simultaneous orthognathic surgery was attempted in the treatment of asymmetric prognathism secondary to condylar OC.
PATIENTS AND METHODS Patients From November 2007 to December 2010, a total of 13 patients with mandibular condylar OC were treated at the Department of Oral and Craniomaxillofacial Science, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine. Patients (9 women and 4 men) had a median age of 26.5 years (range, 15–40 y). The first symptom noticed was a gradual facial asymmetry and chin deviation over the years. The mean duration of facial asymmetry before treatment was 4.6 years (range, 0.5–10 y). Occlusal canting and disorders were noted in all patients preoperatively. All patients had an open bite or locked occlusion on the affected side and a cross-bite on the other side (Fig. 1; Table 1). This study was approved by the hospital’s institutional review board, and informed consent agreement was signed.
The Journal of Craniofacial Surgery • Volume 25, Number 4, July 2014
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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After simulation, virtual wafers and guides for intraoperative use were manufactured by rapid phototyping technology.
Surgery
FIGURE 1. Presurgical facial view, occlusion, and radiologic images. A, Front facial view. B, Locked occlusion on the right side and cross-bite on the left side. C, Axial CT showed a lesion developing from the medial aspect of the left condylar head. D, Panoramic radiograph showed a radiopacity located medial to the left condyle.
Preoperative Planning and Simulation A preoperative thin-cut (1.25 mm), spiral, computed tomographic (CT) scan (Light speed 16; GE, Gloucestershire, United Kingdom) was obtained for all 13 patients. The patients’ individual anatomy and OC were assessed using Surgicase software, version 5.0 (Materialise, Leuven, Belgium) in multiplanar (axial, coronal, and sagittal) and three-dimensional views. The boundary of the tumor and the osteotomy line were delineated on a three-dimensional reconstruction model based on CT scan. Orthognathic surgical planning was designed on the basis of cephalometric analysis and threedimensional reconstruction model evaluation. Virtual condylectomy and orthognathic surgery were performed on the model. To correct the remaining facial asymmetry, median sagittal plane was used as reference plane. The normal anatomic structures were mirrored from the contralateral side, such that the desired contour of the affected side was visualized. With the side-to-side comparison, the asymmetric regions to be revised were defined and displayed on the threedimensional reconstruction image with different colors (Fig. 2).
Preoperative orthodontic treatment was carried out for alignment and decompensation of dentition before surgery. The operations were performed under general anesthesia through nasoendotracheal intubation. According to preoperative surgical planning, maxillary Le Fort I osteotomy was performed for decanting and/or advancement. Osteochondroma resection and condylectomy were carried out endoscopically via intraoral approach. The maximum mouth opening was maintained by a standard mouth prop. A buccal maxillary incision was made from the level of the mandibular second molar to the level of the maxillary teeth. Buccal and lingual mucoperiosteal flaps were elevated. Subperiosteal dissection along the condylar neck and head was carried out until the condyle was fully exposed. Two malleable retractors were placed laterally and medially to protect the buccal and lingual soft tissue. The coronoid process was osteotomized at the level of the mandibular notch using a reciprocating saw and osteotome and was then removed to expose the condyle. With a 4-mm–diameter, 30-degree endoscope (Stryker Corporation; Kalamazoo, Michigan) in the wound, bony anatomic landmarks of the ramus-condyle unit were identified. A direct vision of the magnified and illuminated operative field was realized under the assistance of endoscope. A titanium screw tied with a stainless steel wire was fixed on the exostosis, which can be used to facilitate the dissection and removal of tumors. The osteotomy was performed according to presurgical planning using a long-shafted reciprocating blade. The TMJ capsule and the lateral pterygoid muscle were dissected off the condylar head and neck. Then, the lesion with the affected condyle was removed (Fig. 3). After completion of contralateral SSRO, the mandibular dentition was repositioned and fixed with the guidance of dental wafer. Genioplasty was needed in some cases with chin deviation. Using virtual guide, facial recontouring and revision were performed in patients with mandibular body bowing according to presurgical planning.
RESULTS Orthognathic-orthodontic joint treatment combined with endoscopic condylar OC resection was successfully achieved in all patients. The preoperative planning, including OC resection, maxillomandibular
TABLE 1. Patient Characteristics
Case No. 1 2 3 4 5 6 7 8 9 10 11 12 13 Mean (SD)
Age
Sex
Affected Side
22 28 21 26 24 44 24 15 32 21 20 27 40 26.5 (8.1)
M F F F F F M M F M F F F
L R R R R R L R L L R R L
Duration of Facial Asymmetry, y 5 4 4 0.5 10 3 3 4 10 3 7 5 1 4.6 (2.9)
Occlusion Canting
Concomitant Orthognathic Surgery
Follow-up, mo
Y Y Y Y Y Y Y Y Y Y Y Y Y
Le Fort I osteotomy, rSSRO, genioplasty, mandibular contouring Le Fort I osteotomy, lSSRO Le Fort I osteotomy, lSSRO, genioplasty, mandibular contouring Le Fort I osteotomy, lSSRO, mandibular subapical osteotomy Le Fort I osteotomy, lSSRO, mandibular contouring Le Fort I osteotomy, lSSRO Le Fort I osteotomy, rSSRO Le Fort I osteotomy, lSSRO, mandibular contouring Le Fort I osteotomy, rSSRO, mandibular contouring Le Fort I osteotomy, rSSRO, mandibular contouring Le Fort I osteotomy, lSSRO Le Fort I osteotomy, lSSRO, mandibular contouring Le Fort I osteotomy, rSSRO
20 16 28 54 50 47 45 33 27 44 32 43 37 36.6 (11.8)
F, female; L, left; M, male; R, right; Y, yes; rSSRO, right side sagittal split ramus osteotomy; lSSRO, left side sagittal split ramus osteotomy.
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© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 25, Number 4, July 2014
The Treatment of Condylar Osteochondroma
FIGURE 2. Surgical planning and simulation: condylectomy of the left side, Le Fort I osteotomy, right SSRO, and left mandibular body trimming were simulated on the three-dimensional model. A, Frontal view. B, Lateral view.
repositioning, and mandibular revision, was made on the basis of cephalometric analysis and three-dimensional reconstruction model evaluation. Good consistency between preoperative planning and surgery was obtained in all patients. Virtual splints and guides were applied accurately in the positioning and recontouring of jaws, respectively. Osteochondroma resection and conservative condylectomy were successfully carried out in all patients. All operations were performed endoscopically, and no conventional extraoral incision was needed. The magnified endoscopic view allowed the condylar head and neck to be easily dissected from the surrounding soft tissues. A direct vision of the magnified and illuminated operative field was realized under the assistance of endoscope. All patients underwent uneventful healing without any serious complications. No facial nerve injury and salivary fistula occurred. The diagnosis of condylar OC was verified by postoperative pathologic examination. The patients showed no signs of recurrence and TMJ ankylosis in the 16 to 54 months of follow-up. Facial symmetry and morphology were greatly improved, and stable occlusion was obtained in all cases (Fig. 4).
DISCUSSION Clinical features of condylar OC include progressive increasing facial asymmetry, vertical elongation of the face on the affected side, prognathic deviation of the chin, cross-bite on the contralateral side and lateral open bite on the affected side, loss of condylar
FIGURE 3. Endoscope-assisted condylectomy. A, Full exposure of the mandibular condyle and OC. B, A titanium screw tied with a stainless steel wire was fixed on the exostosis to facilitate its removal. C, The osteotomy was performed using a long-shafted reciprocating blade. D, The TMJ capsule and the lateral pterygoid muscle were dissected off the condylar head and neck.
FIGURE 4. Postoperative facial view, occlusion, and radiologic images. A, Front facial view. B, Stable occlusion. C, Axial CT. D, Panoramic radiograph.
function, and other features.5,13 The presentation varies with the size of the tumor and its main vector of growth. In some cases, asymmetric prognathism may occur along with bowing of the lower border of the mandible on the ipsilateral side, whereas compensatory downgrowth of the maxilla due to open bite may give rise to a canting of the maxillary occlusal plane.12 Medical imaging shows great value in clinical diagnosis of condylar OC. From panoramic radiography, we can see exophytic masses with mixed density and sclerotic appearance. Computed tomography and magnetic resonance imaging examination can be used in evaluating the lesion and associated structures. Although a preliminary tentative diagnosis can be made on the basis of clinical and radiographic findings, confirmation can be obtained only after histopathologic analysis of the specimen. To correct asymmetric deformity and malocclusion, individual surgical planning is indispensable. Besides condylectomy, in different situations, SSRO, Le Fort I maxillary osteotomy, genioplasty, and lower border osteotomy might be required. Three-dimensional virtual surgical planning and simulation allow surgeons to try out different surgical procedures to find the optimal method before operation.14 The boundary of the tumor was defined and osteotomy line was delineated on the three-dimensional reconstruction model based on CT scan. Through mirroring comparison, the scope and amount of asymmetry that need to be revised can be displayed, and therefore, facial symmetry can be maximally guaranteed. There are various surgical approaches for the treatment of condylar OC.15 The preauricular entry into the joint, alone or in combination with other incisions, is the most often used.16 However, for the reason that most OCs are located medially to the condyle, the preauricular approach has its disadvantages. The surgical entry can be limited by the zygomatic arch, and the articular capsule needs to be opened for tumor resection. Therefore, an intraoral surgical incision was tried to excise the tumor.6 The argument against this approach is the possible concern of inadequate removal of the tumor with recurrence of lesion or possible malignant change. Although a general recurrence rate of approximately 2% has been reported for OC, no case of either recurrence or malignant transformation has been reported in the mandible.17 In this study, 13 conservative condylectomies were performed intraorally, and no tumor recurrence was found in the 16 to 54 months of follow-up. With the aid of endoscope, the condyle and lesion can be exposed and visualized intraorally. The tumor resection and conservative condylectomy combined with condylar reshaping were performed
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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successfully. Facial nerve injury and salivary fistula were avoided by intraoral approach. The benefits of endoscopic surgery still include small and inconspicuous incisions and scars, minimal dissection, and direct visualization of an illuminated and magnified operative field.9,18 The results of this preliminary and ongoing case series indicate that this minimally invasive approach to the ramus-condyle unit is feasible and can be carried out with decreased morbidity and rapid recovery. Long-term stability of facial morphology and occlusion is the goal we have been pursuing. Tumor recurrence and occlusion are the 2 main factors related to postoperative stability. In this study, all patients showed no signs of relapse in the follow-up. Preoperative accurate definition of tumor boundary, direct visualization of the illuminated and magnified operative field, and en bloc resection can reduce the risk for tumor recurrence. Ideal occlusion can be obtained by orthognathic and orthodontic joint treatment. Thus, good occlusal function and facial morphology accompanied with long-term stability can be realized. Currently, endoscopic condylectomy combined with orthognathic surgery in the treatment of asymmetric prognathism caused by condylar OC is still in its infancy, and few studies have been reported.6 However, endoscope-assisted condylar OC resection via intraoral approach offers great advantages with no significant complications compared with conventional extraoral incisions. The secondary deformities and malocclusion can be corrected by simultaneous orthognathic surgery. Therefore, endoscope-assisted condylectomy combined with orthognathic surgery provides us a valuable option for this complicated procedure.
REFERENCES 1. Wolford LM. Clinical indications for simultaneous TMJ and orthognathic surgery. Cranio 2007;25:273–282 2. Koga M, Toyofuku S, Nakamura Y, et al. Osteochondroma in the mandibular condyle that caused facial asymmetry: a case report. Cranio 2006;24:67–70 3. Iizuka T, Schroth G, Laeng RH, et al. Osteochondroma of the mandibular condyle: report of a case. J Oral Maxillofac Surg 1996;54:495–501
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4. Peroz I, Scholman HJ, Hell B. Osteochondroma of the mandibular condyle: a case report. Int J Oral Maxillofac Surg 2002;31:455–456 5. Wolford LM, Mehra P, Franco P. Use of conservative condylectomy for treatment of osteochondroma of the mandibular condyle. J Oral Maxillofac Surg 2002;60:262–268 6. Eller DJ, Blakemore JR, Stein M. Transoral resection of a condylar osteochondroma: report of case. J Oral Surg 1977;5:409–413 7. Chen L, Sun W, Wu PN, et al. Endoscope-assisted versus conventional second branchial cleft cyst resection. Surg Endosc 2012;26:13971402 8. Hüscher CS, Chiodini S, Napolitano C, et al. Endoscopic right thyroid lobectomy. Surg Endosc 1997;11:877 9. Troulis MJ, Williams WB, Kaban LB. Endoscopic mandibular condylectomy and reconstruction: early clinical results. J Oral Maxillofac Surg 2004;62:460–465 10. Sembronio S, Albiero AM, Polini F, et al. Intraoral endoscopically assisted treatment of temporomandibular joint ankylosis: preliminary report. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104:e7–e10 11. Deng M, Long X, Cheng AH, et al. Modified trans-oral approach for mandibular condylectomy. Int J Oral Maxillofac Surg 2009; 38:374–377 12. Ord RA, Warburton G, Caccamese JF. Osteochondroma of the condyle: review of 8 cases. Int J Oral Maxillofac Surg 2010;39:523–528 13. Seki H, Fukuda M, Takahashi T, et al. Condylar osteochondroma with complete hearing loss: report of a case. Int J Oral Maxillofac Surg 2004;33:549–553 14. Yang X, Hu J, Zhu S, et al. Computer-assisted surgical planning and simulation for condylar reconstruction in patients with osteochondroma. Br J Oral Maxillofac Surg, 2011;49:203–208 15. Roychoudhury A, Bhatt K, Yadav R, et al. Review of osteochondroma of mandibular condyle and report of a case series. J Oral Maxillofac Surg 2011;69:2815–2823 16. Ward BB, Pires CA, Feinberg SE. Osteochondromas of the mandible: case reports and rationale for treatment. J Oral Maxillofac Surg 2005;63:1039–1044 17. Holmlund AB, Gynther GW, Reinholt FP. Surgical treatment of osteochondroma of the mandibular condyle in the adult. A 5-year follow-up. Int J Oral Maxillofac Surg 2004; 33:549–553 18. Troulis MJ, Kaban LB. Endoscopic approach to the ramus/condyle unit: clinical applications. J Oral Maxillofac Surg 2001;59:503–509
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
Endoscope-Assisted Conservative Condylectomy Combined With Orthognathic Surgery in the Treatment of Mandibular Condylar Osteochondroma Hongbo Yu, DDS, MD,* Feifei Jiao, MB,† Biao Li, DDS,* Lei Zhang, DDS, MD,* Steve Guofang Shen, DDS, MD,* and Xudong Wang, DDS, MD*
Abstract: Mandibular condylar osteochondroma (OC) results in asymmetric prognathism with facial morphologic and functional disturbance. The aim of this study was to explore the feasibility of endoscope-assisted conservative condylectomy combined with simultaneous orthognathic surgery in the treatment of condylar OC. Thirteen patients with OC of the mandibular condyle were enrolled in this study. With the aid of endoscope, condylar OC resection and conservative condylectomy were carried out via intraoral approach. A direct vision of the magnified and illuminated operative field was realized. Simultaneous orthognathic surgery was used to correct facial asymmetry and malocclusion. All patients healed uneventfully. No facial nerve injury and salivary fistula occurred. Facial symmetry and morphology were greatly improved, and stable occlusion was obtained in all cases. The patients showed no signs of recurrence and temporomandibular joint ankylosis in the 16 to 54 months of follow-up. Endoscope-assisted tumor resection and condylectomy combined with simultaneous orthognathic surgery provide us a valuable option in the treatment of mandibular condylar OC. Key Words: Condylar osteochondroma, endoscope, conservative condylectomy, orthognathic surgery, asymmetric prognathism (J Craniofac Surg 2014;25: 1379–1382)
From the *Department of Oral and Craniomaxillofacial Science, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, People’s Republic of China; and †China-Japan Friendship Dental Clinic, Shanghai Stomatological Disease Center, Shanghai, People’s Republic of China. Received October 5, 2013. Accepted for publication February 8, 2014. Address correspondence and reprint requests to Xudong Wang, DDS, MD, and Steve Guofang Shen, DDS, MD, Department of Oral and Craniomaxillofacial Science, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, 200011, Shanghai, People’s Republic of China; E-mail: [email protected] Hongbo Yu and Feifei Jiao contributed equally to this study. Steve Guofang Shen and Xudong Wang are co–corresponding authors. Supported by grant 81101131 from the National Natural Science Foundation of China and combined Medicine and Engineering Project of Shanghai Jiao Tong University (YG2013MS56). The authors report no conflicts of interest. Copyright © 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000000862
O
steochondroma (OC), also known as osteocartilaginous exostosis, is one of the most common benign tumors of long bones but is rarely found in facial skeleton. However, mandibular condylar OC can result in morphologic and functional disturbance, including facial asymmetry, malocclusion, and temporomandibular joint (TMJ) dysfunction.1,2 Therefore, the treatment of condylar OC should include not only surgical excision of the lesion but also the correction of dentomaxillofacial deformities.3,4 At present, condylar OC resection and condylectomy combined with orthognathic surgery are a proposed option for the treatment of condylar OC.1,5 For condylectomy, the preauricular approach, either on its own or in combination with cervical incisions, is the most popular used. However, the conventional resection has a risk for facial nerve injury and sometimes leaves a prominent scar on the face.6 Endoscopic surgery has been used more frequently in the head and neck area since the end of the 1990s.7,8 Recently, there were a few reports of its application in the treatment of TMJ ankylosis, condylectomy, and condylar reconstruction.9–11 For the reason that endoscope has advantages including small incisions, minor tissue damage, and direct vision of a magnified and illuminated operative field, we tried its application in the treatment of condylar OC. To correct facial asymmetry and malocclusion, orthognathic surgery is an essential option.1 In different situations, mandibular sagittal split ramus osteotomies (SSROs), Le Fort I maxillary osteotomies, genioplasties, and lower border osteotomies might be required.12 For the reason that the secondary deformities are complex and variable, individualized preoperative surgical planning is indispensable. In this study, endoscope-assisted condylar OC resection combined with simultaneous orthognathic surgery was attempted in the treatment of asymmetric prognathism secondary to condylar OC.
PATIENTS AND METHODS Patients From November 2007 to December 2010, a total of 13 patients with mandibular condylar OC were treated at the Department of Oral and Craniomaxillofacial Science, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine. Patients (9 women and 4 men) had a median age of 26.5 years (range, 15–40 y). The first symptom noticed was a gradual facial asymmetry and chin deviation over the years. The mean duration of facial asymmetry before treatment was 4.6 years (range, 0.5–10 y). Occlusal canting and disorders were noted in all patients preoperatively. All patients had an open bite or locked occlusion on the affected side and a cross-bite on the other side (Fig. 1; Table 1). This study was approved by the hospital’s institutional review board, and informed consent agreement was signed.
The Journal of Craniofacial Surgery • Volume 25, Number 4, July 2014
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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The Journal of Craniofacial Surgery • Volume 25, Number 4, July 2014
Yu et al
After simulation, virtual wafers and guides for intraoperative use were manufactured by rapid phototyping technology.
Surgery
FIGURE 1. Presurgical facial view, occlusion, and radiologic images. A, Front facial view. B, Locked occlusion on the right side and cross-bite on the left side. C, Axial CT showed a lesion developing from the medial aspect of the left condylar head. D, Panoramic radiograph showed a radiopacity located medial to the left condyle.
Preoperative Planning and Simulation A preoperative thin-cut (1.25 mm), spiral, computed tomographic (CT) scan (Light speed 16; GE, Gloucestershire, United Kingdom) was obtained for all 13 patients. The patients’ individual anatomy and OC were assessed using Surgicase software, version 5.0 (Materialise, Leuven, Belgium) in multiplanar (axial, coronal, and sagittal) and three-dimensional views. The boundary of the tumor and the osteotomy line were delineated on a three-dimensional reconstruction model based on CT scan. Orthognathic surgical planning was designed on the basis of cephalometric analysis and threedimensional reconstruction model evaluation. Virtual condylectomy and orthognathic surgery were performed on the model. To correct the remaining facial asymmetry, median sagittal plane was used as reference plane. The normal anatomic structures were mirrored from the contralateral side, such that the desired contour of the affected side was visualized. With the side-to-side comparison, the asymmetric regions to be revised were defined and displayed on the threedimensional reconstruction image with different colors (Fig. 2).
Preoperative orthodontic treatment was carried out for alignment and decompensation of dentition before surgery. The operations were performed under general anesthesia through nasoendotracheal intubation. According to preoperative surgical planning, maxillary Le Fort I osteotomy was performed for decanting and/or advancement. Osteochondroma resection and condylectomy were carried out endoscopically via intraoral approach. The maximum mouth opening was maintained by a standard mouth prop. A buccal maxillary incision was made from the level of the mandibular second molar to the level of the maxillary teeth. Buccal and lingual mucoperiosteal flaps were elevated. Subperiosteal dissection along the condylar neck and head was carried out until the condyle was fully exposed. Two malleable retractors were placed laterally and medially to protect the buccal and lingual soft tissue. The coronoid process was osteotomized at the level of the mandibular notch using a reciprocating saw and osteotome and was then removed to expose the condyle. With a 4-mm–diameter, 30-degree endoscope (Stryker Corporation; Kalamazoo, Michigan) in the wound, bony anatomic landmarks of the ramus-condyle unit were identified. A direct vision of the magnified and illuminated operative field was realized under the assistance of endoscope. A titanium screw tied with a stainless steel wire was fixed on the exostosis, which can be used to facilitate the dissection and removal of tumors. The osteotomy was performed according to presurgical planning using a long-shafted reciprocating blade. The TMJ capsule and the lateral pterygoid muscle were dissected off the condylar head and neck. Then, the lesion with the affected condyle was removed (Fig. 3). After completion of contralateral SSRO, the mandibular dentition was repositioned and fixed with the guidance of dental wafer. Genioplasty was needed in some cases with chin deviation. Using virtual guide, facial recontouring and revision were performed in patients with mandibular body bowing according to presurgical planning.
RESULTS Orthognathic-orthodontic joint treatment combined with endoscopic condylar OC resection was successfully achieved in all patients. The preoperative planning, including OC resection, maxillomandibular
TABLE 1. Patient Characteristics
Case No. 1 2 3 4 5 6 7 8 9 10 11 12 13 Mean (SD)
Age
Sex
Affected Side
22 28 21 26 24 44 24 15 32 21 20 27 40 26.5 (8.1)
M F F F F F M M F M F F F
L R R R R R L R L L R R L
Duration of Facial Asymmetry, y 5 4 4 0.5 10 3 3 4 10 3 7 5 1 4.6 (2.9)
Occlusion Canting
Concomitant Orthognathic Surgery
Follow-up, mo
Y Y Y Y Y Y Y Y Y Y Y Y Y
Le Fort I osteotomy, rSSRO, genioplasty, mandibular contouring Le Fort I osteotomy, lSSRO Le Fort I osteotomy, lSSRO, genioplasty, mandibular contouring Le Fort I osteotomy, lSSRO, mandibular subapical osteotomy Le Fort I osteotomy, lSSRO, mandibular contouring Le Fort I osteotomy, lSSRO Le Fort I osteotomy, rSSRO Le Fort I osteotomy, lSSRO, mandibular contouring Le Fort I osteotomy, rSSRO, mandibular contouring Le Fort I osteotomy, rSSRO, mandibular contouring Le Fort I osteotomy, lSSRO Le Fort I osteotomy, lSSRO, mandibular contouring Le Fort I osteotomy, rSSRO
20 16 28 54 50 47 45 33 27 44 32 43 37 36.6 (11.8)
F, female; L, left; M, male; R, right; Y, yes; rSSRO, right side sagittal split ramus osteotomy; lSSRO, left side sagittal split ramus osteotomy.
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© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 25, Number 4, July 2014
The Treatment of Condylar Osteochondroma
FIGURE 2. Surgical planning and simulation: condylectomy of the left side, Le Fort I osteotomy, right SSRO, and left mandibular body trimming were simulated on the three-dimensional model. A, Frontal view. B, Lateral view.
repositioning, and mandibular revision, was made on the basis of cephalometric analysis and three-dimensional reconstruction model evaluation. Good consistency between preoperative planning and surgery was obtained in all patients. Virtual splints and guides were applied accurately in the positioning and recontouring of jaws, respectively. Osteochondroma resection and conservative condylectomy were successfully carried out in all patients. All operations were performed endoscopically, and no conventional extraoral incision was needed. The magnified endoscopic view allowed the condylar head and neck to be easily dissected from the surrounding soft tissues. A direct vision of the magnified and illuminated operative field was realized under the assistance of endoscope. All patients underwent uneventful healing without any serious complications. No facial nerve injury and salivary fistula occurred. The diagnosis of condylar OC was verified by postoperative pathologic examination. The patients showed no signs of recurrence and TMJ ankylosis in the 16 to 54 months of follow-up. Facial symmetry and morphology were greatly improved, and stable occlusion was obtained in all cases (Fig. 4).
DISCUSSION Clinical features of condylar OC include progressive increasing facial asymmetry, vertical elongation of the face on the affected side, prognathic deviation of the chin, cross-bite on the contralateral side and lateral open bite on the affected side, loss of condylar
FIGURE 3. Endoscope-assisted condylectomy. A, Full exposure of the mandibular condyle and OC. B, A titanium screw tied with a stainless steel wire was fixed on the exostosis to facilitate its removal. C, The osteotomy was performed using a long-shafted reciprocating blade. D, The TMJ capsule and the lateral pterygoid muscle were dissected off the condylar head and neck.
FIGURE 4. Postoperative facial view, occlusion, and radiologic images. A, Front facial view. B, Stable occlusion. C, Axial CT. D, Panoramic radiograph.
function, and other features.5,13 The presentation varies with the size of the tumor and its main vector of growth. In some cases, asymmetric prognathism may occur along with bowing of the lower border of the mandible on the ipsilateral side, whereas compensatory downgrowth of the maxilla due to open bite may give rise to a canting of the maxillary occlusal plane.12 Medical imaging shows great value in clinical diagnosis of condylar OC. From panoramic radiography, we can see exophytic masses with mixed density and sclerotic appearance. Computed tomography and magnetic resonance imaging examination can be used in evaluating the lesion and associated structures. Although a preliminary tentative diagnosis can be made on the basis of clinical and radiographic findings, confirmation can be obtained only after histopathologic analysis of the specimen. To correct asymmetric deformity and malocclusion, individual surgical planning is indispensable. Besides condylectomy, in different situations, SSRO, Le Fort I maxillary osteotomy, genioplasty, and lower border osteotomy might be required. Three-dimensional virtual surgical planning and simulation allow surgeons to try out different surgical procedures to find the optimal method before operation.14 The boundary of the tumor was defined and osteotomy line was delineated on the three-dimensional reconstruction model based on CT scan. Through mirroring comparison, the scope and amount of asymmetry that need to be revised can be displayed, and therefore, facial symmetry can be maximally guaranteed. There are various surgical approaches for the treatment of condylar OC.15 The preauricular entry into the joint, alone or in combination with other incisions, is the most often used.16 However, for the reason that most OCs are located medially to the condyle, the preauricular approach has its disadvantages. The surgical entry can be limited by the zygomatic arch, and the articular capsule needs to be opened for tumor resection. Therefore, an intraoral surgical incision was tried to excise the tumor.6 The argument against this approach is the possible concern of inadequate removal of the tumor with recurrence of lesion or possible malignant change. Although a general recurrence rate of approximately 2% has been reported for OC, no case of either recurrence or malignant transformation has been reported in the mandible.17 In this study, 13 conservative condylectomies were performed intraorally, and no tumor recurrence was found in the 16 to 54 months of follow-up. With the aid of endoscope, the condyle and lesion can be exposed and visualized intraorally. The tumor resection and conservative condylectomy combined with condylar reshaping were performed
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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successfully. Facial nerve injury and salivary fistula were avoided by intraoral approach. The benefits of endoscopic surgery still include small and inconspicuous incisions and scars, minimal dissection, and direct visualization of an illuminated and magnified operative field.9,18 The results of this preliminary and ongoing case series indicate that this minimally invasive approach to the ramus-condyle unit is feasible and can be carried out with decreased morbidity and rapid recovery. Long-term stability of facial morphology and occlusion is the goal we have been pursuing. Tumor recurrence and occlusion are the 2 main factors related to postoperative stability. In this study, all patients showed no signs of relapse in the follow-up. Preoperative accurate definition of tumor boundary, direct visualization of the illuminated and magnified operative field, and en bloc resection can reduce the risk for tumor recurrence. Ideal occlusion can be obtained by orthognathic and orthodontic joint treatment. Thus, good occlusal function and facial morphology accompanied with long-term stability can be realized. Currently, endoscopic condylectomy combined with orthognathic surgery in the treatment of asymmetric prognathism caused by condylar OC is still in its infancy, and few studies have been reported.6 However, endoscope-assisted condylar OC resection via intraoral approach offers great advantages with no significant complications compared with conventional extraoral incisions. The secondary deformities and malocclusion can be corrected by simultaneous orthognathic surgery. Therefore, endoscope-assisted condylectomy combined with orthognathic surgery provides us a valuable option for this complicated procedure.
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© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
