TECHNICAL STRATEGY
Modified Condylar Distraction Osteogenesis via Single Preauricular Incision for Treatment of Temporomandibular Joint Ankylosis Jie Xu, PhD,* Xing Long, DDS, PhD,* Andrew Hua-an Cheng, BDS, MBBS,† Hengxing Cai, PhD,* Mohong Deng, PhD,* and Qinggong Meng, PhD* Background: Temporomandibular joint (TMJ) ankylosis with facial asymmetry is still controversial to deal with. This study describes a modified condylar distraction osteogenesis protocol via preauricular approach for the treatment of this condition. Methods: From 2006 to 2013, 18 patients with TMJ ankylosis were enrolled. The Wuhan TMJ Ankylosis treatment protocol includes as follows: (1) preauricular approach is the only surgical access; (2) TMJ arthroplasty is used to recontour the condylar head, and the vertical height of condyle is maintained; (3) distractor placement with distractor port exiting via preauricular incision; (4) distraction after 5 to 7 days of latency period with 0.5 mm twice daily; and (5) distractor removal after 3-month consolidation through preauricular incision. All patients had clinical follow-up and detailed examination. Results: All patients had satisfactory results postoperatively. The mean (range) mouth opening increased from 7.1 (0–18) to 32.1 (28–43) mm during 37 (6–81) months of follow-up period (P < 0.01). Facial asymmetry was corrected in all patients, and all patients had minimal postoperative scar perception of the preauricular incision. Conclusions: The Wuhan TMJ ankylosis protocol provides a safe and effective treatment alternative in managing TMJ ankylosis, especially in young women who are anxious about perceptive extraoral scar. Key Words: TMJ ankylosis, distraction osteogenesis, preauricular incision (J Craniofac Surg 2015;26: 509–511)
T
emporomandibular joint (TMJ) ankylosis is an uncommon condition in developed countries. However, it is still a common condition that affects patients in developing countries. Trauma and infection are the main causes of this devastating condition.1 Functionally, TMJ ankylosis severely restricts patient's mouth opening and causes difficulty in speech, mastication, and oral hygiene. Structurally, ankylosed TMJ often results in mandibular deformity,
From the *Department of Oral and Maxillofacial Surgery, The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine, Ministry of Education, School & Hospital of Stomatology, Wuhan University, Hubei, P.R. China; and †Oral and Maxillofacial Surgery Unit, Royal Adelaide Hospital, Adelaide, Australia. Received June 2, 2014. Accepted for publication July 31, 2014. Address correspondence and reprint requests to Xing Long, DDS, PhD, Key Laboratory of Oral Biomedical Engineering of Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan 430079, P.R. China; E-mail: [email protected] The authors report no conflicts of interest. Copyright © 2015 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001291
facial asymmetry, and obstructive sleep apnea in growing patients. Release of ankylosis, restoration of functional ramus height, and long-term maintenance of TMJ mobility are important elements of TMJ ankylosis management. Bone graft,2 alloplastic TMJ replacement,3 and distraction osteogenesis4 (DO) were all documented treatment modalities for the treatment of TMJ ankylosis with facial asymmetry. In recent years, DO has become an established treatment modality in treating TMJ ankylosis. The DO has the advantages of avoiding donor-site morbidity, gradual soft tissue adaptation, and predictable bone lengthening.5 Kaban et al6 has documented the Massachusetts General Hospital TMJ Ankylosis Protocol, which is a 7-step protocol. The protocol involves aggressive resection, coronoidectomy, lining of articular surface with temporalis flap or remaining TMJ disc, DO/ costochondral graft, early mobilization, and aggressive physiotherapy. It is a well-established protocol, but arthroplasty has been reported by other authors in releasing TMJ ankylosis.7 It reduces the amount of the condylar/ramus height that needed to be restored with DO. The Kaban protocol also requires a combination of preauricular and submandibular incisions. The extraoral incisions in the Chinese population often result in hypertrophic or keloid scarring. Many of the patients who seek reconstruction of TMJ ankylosis were young women who are concerned about postoperative scar. The distractor removal is often difficult, if not impossible, with the current condylar distraction protocol. Therefore, we present the Wuhan TMJ Ankylosis Protocol and its results of 18 cases using modified arthroplasty and condylar DO via preauricular incision.
MATERIALS AND METHODS From 2006 to 2013, 18 patients (7 women and 11 men) with TMJ ankylosis who presented to the Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, China, were enrolled into this study. All patients have been given informed consents, and the treatment protocol and study design were approved by the ethics committee of the School and Hospital of Stomatology, Wuhan University. There were 13 unilateral and 5 bilateral TMJ ankylosis cases in the study. Fifteen patients with TMJ ankylosis had previous mandibular trauma, and the other 3 patients had no clear identifiable cause for their TMJ ankylosis. The patients were aged 15 to 36 years (mean, 20.4 y). All patients had preoperative and postoperative clinical examination, radiographs, and CT scan. All patients were followed up with a postoperative regimen for a mean of 37 months (range, 6–81 mo).
Surgical Technique The patient was anesthetized and intubated with nasoendotracheal tube. The affected TMJ was exposed with preauricular incision as described by Al-Kayat and Bramley.8 The lateral aspect of the ankylosed bony mass was osteotomized and removed with saw and bur to expose the junction between the condyle and glenoid
The Journal of Craniofacial Surgery • Volume 26, Number 2, March 2015
Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
509
The Journal of Craniofacial Surgery • Volume 26, Number 2, March 2015
Xu et al
fossa. The condyle and glenoid fossa were carefully separated with a combination of osteotome and periosteal elevator. The medial aspect of the mandibular condyle and glenoid fossa could be inspected and recontoured, respectively, to form a new joint articulation. The ipsilateral coronoidectomy was performed to increase interincisal distance. If the mouth opening was not more than 30 mm, then contralateral coronoidectomy was performed if necessary. If there was a residual disk that can be identified, the disk should be repositioned and sutured to the lateral TMJ capsule. The distraction vector was determined by the direction of the mandibular posterior border. A distractor (Ningbo Cibei, China) was chosen and fixated parallel to the posterior border of mandible. The distractor was positioned to have the distractor port exiting through the preauricular incision (Fig. 1). Osteotomy of the condylar stump was made at the level of sigmoid notch after the positioning of distractor. The length of the condylar stump needed to be greater than 10 mm to ensure adequate bulk. The osteotomy was perpendicular to the posterior border of mandible. The distractor port was protected with a plastic tube to facilitate postoperative drainage and also make the activation of distractor port less painful. The tube was secured with nylon skin suture and removed when distraction protocol is completed. Mouth opening exercise was recommended on the third day postoperatively. After the latency period of 5 to 7days, the device was activated at a rate of 0.5 mm twice daily. The condylar stump was distracted until the correction of midline deviation was achieved. In bilateral cases, the distraction was completed when the desired vertical mandibular height was achieved. Weekly postoperative panoramic radiograph was taken during the distraction period. The distractor was maintained in situ as an internal fixator during the consolidation phase for at least 3 months. After 3-month consolidation, conventional helical CT was used to evaluate the extent of ossification of the distraction site. Removal of the distraction device was achieved using the same preauricular incision. In some cases, pseudo disks were found between condyle and fossa (Fig. 2).
RESULT The clinical characteristics and outcomes of patients were summarized. A total of 18 patients were enrolled, and all patients had satisfactory results postoperatively (Fig. 3). The mean (range) mouth opening significantly increased from 7.1 (0–18) to 32.1 (28– 43) mm in 37 (6–81) months of follow-up (P < 0.01). Mean (range) length increase by DO was 12.3 (6.8–21) mm. Facial asymmetry was corrected, and mean (range) length increase from condyle to
FIGURE 1. Osteotomy line was made at the condyle neck, and the distractor was reversed with its port exiting through the preauricular incision.
510
FIGURE 2. Between the new condyle and the fossa, a pseudodisk was found during the operation for removal of distractor (arrow).
mandibular notch was 10.7 (6–17) mm (P < 0.01) (Fig. 4). Preauricular scar was inconspicuous for all patients (Fig. 5). No patients complained about excessive pain at the distraction site. The only complication was distractor breakage in 1 patient that resulted in poor ossification at the distraction site. This was due to patient's noncompliance to nonchew hard diet during the 3-month consolidation period.
DISCUSSION In our study cohort, skin scars had been unconspicuous in all patients. No patient complained about the facial scarring. The incidence of postoperative facial scarring is usually not clearly documented. In a study of retromandibular approach for open reduction and internal fixation of condylar neck fracture, Ellis et al9 documented 7.5% of facial scarring rate. The authors would agree that the incidence of hypertrophic scar is higher in the Chinese population compared with that in the whites.10 The scarring often creates psychologic stress in patients who already experience significant facial deformities. A carefully designed and executed preauricular incision can minimize troublesome facial scarring. It is an obvious treatment alternative in treating patients with TMJ ankylosis who are anxious about postoperative unsightly scars. The arthroplasty technique of TMJ ankylosis release reduces the amount of dead space that is within the affected TMJ. The amount of bone that is needed to be regenerated from DO is significantly reduced. The lateral TMJ capsule and remaining TMJ disk can be used as sufficient liner of the glenoid fossa. In patients who had multiple operations, temporalis myofascial flap might be the only remaining option for lining the glenoid fossa. The positioning of the distractor is the major difference between the Wuhan protocol and other technique. First, the distractor is positioned at the sigmoid notch level along the posterior mandibular border. This is because the arthroplasty enables the osteotomy site to be carried out at the level of sigmoid notch. It is impossible
FIGURE 3. A, Bony mass was observed at the right condylar head, resulting in bony ankylosis. B, Osteotomy was made at the level of sigmoid notch. C, Cessation of distraction when the correction of midline deviation was achieved. D, Bone formation at the distraction gap 3 months after removal of distractor.
© 2015 Mutaz B. Habal, MD
Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 26, Number 2, March 2015
FIGURE 4. Chin midline was deviated preoperatively (A) or before distraction (B). Chin midline coincided with the maxillary midline postoperatively (C).
to achieve if a gap osteotomy was used to release the ankylosis. The modification enables and simplifies the fixation of the distractor via a preauricular incision. The distractor port is positioned in such a way that it exits via the preauricular incision. The capsular soft tissue around the foot plates of distractor is carefully approximated to reduce the chance of postoperative infection. Removal of distractor at the end of the consolidation period is another clinical problem that the surgeon encounters. The condylar stump is transported into the glenoid fossa and cannot be retrieved through a submandibular incision.11 By using the Wuhan protocol, all plates and screws can be exposed and removed via the same incision. This is a major modification from other studies because the superior foot plates are often left in situ because of access difficulty. The plastic tubing around the distractor port allows adequate drainage of the potential hematoma, which reduces the chance of developing a fibro-osseous ankylosis in the short term.7 However, early mobilization and continuous mouth opening exercise are also important in reducing reankylosis rate. The blood supply to condyle requires special consideration in managing any TMJ surgical pathology. The inferior alveolar artery and small arteries of the TMJ capsule form a complex capillary network that supplies the condylar head. The vessels penetrate the capsule in various locations and forms branches within the capsule and within the periosteum.12 Resorption, aseptic osteomyelitis, and necrosis of the condylar head are the most common postoperative complications when the surgical approach compromises the delicate TMJ blood supply.13 Using scanning electron microscope, Choi et al14 demonstrated vasculature within the bone and periosteum, which forms anastomosis at the distraction site. The vascular network can also supply the condylar stump during distraction period. In this
FIGURE 5. Facial asymmetry was significantly corrected in lateral view (A, D) or anterior view (B, E), preauricular scar was inconspicuous (D, E), and mouth opening increased significantly from 1.3 to 3.5 cm (C, F) after 6 months of follow-up.
Modified Condylar DO for TMJ Ankylosis
series, there was no adverse TMJ condylar head complication; the authors postulated that careful preservation of the medial pterygoid and masseter muscle attachment can be achieved using this technique. The ankylosis site and medial aspect of the ankylosis can be accessed without difficulty. The common dreaded complication of DO is infection around the distraction device. Norholt et al15 reported 12% of infection rate at the distraction site. However, the cohorts in this study did not have any postoperative infection. In this study, the only 1 case with distractor breakage is due to noncompliance to the nonchew hard diet protocol. This highlighted the importance of preoperative patient selection and patient education. Careful treatment planning, surgical execution, and meticulous postoperative care are all essential in the management of such patients.
CONCLUSIONS The Wuhan TMJ Ankylosis Protocol is a safe and effective treatment alternative in the management of TMJ ankylosis with facial asymmetry, especially in young female patients who are anxious about postoperative scars.
REFERENCES 1. Atac MS, Cakir M, Yucel E, et al. Early treatment of unilateral temporomandibular joint ankylosis: a multidisciplinary approach. J Craniofac Surg 2014;25:e213–e216 2. Kummoona R. Temporomandibular joint reconstruction with a 2-part chrome-cobalt prosthesis, chondro-osseous graft, and silastic: clinical and experimental studies. J Craniofac Surg 2009;20:2125–2135 3. Cascone P, Gennaro P, Gabriele G, et al. Functional outcomes in bilateral temporomandibular joint ankylosis treated with stock prosthesis. J Craniofac Surg 2013;24:E139–E141 4. Singh DJ, Glick PH, Bartlett SP. Mandibular deformities: single-vector distraction techniques for a multivector problem. J Craniofac Surg 2009;20:1468–1472 5. Pereira MA, Luiz de Freitas PH, da Rosa TF, et al. Understanding distraction osteogenesis on the maxillofacial complex: a literature review. J Oral Maxillofac Surg 2007;65:2518–2523 6. Kaban LB, Bouchard C, Troulis MJ. A protocol for management of temporomandibular joint ankylosis in children. J Oral Maxillofac Surg 2009;67:1966–1978 7. Long X, Li X, Cheng Y, et al. Preservation of disc for treatment of traumatic temporomandibular joint ankylosis. J Oral Maxillofac Surg 2005;63:897–902 8. Al-Kayat A, Bramley P. A modified pre-auricular approach to the temporomandibular joint and malar arch. Br J Oral Surg 1979;17:91–103 9. Ellis E III, McFadden D, Simon P, et al. Surgical complications with open treatment of mandibular condylar process fractures. J Oral Maxillofac Surg 2000;58:950–958 10. Li-Tsang CW, Lau JC, Chan CC. Prevalence of hypertrophic scar formation and its characteristics among the Chinese population. Burns 2005;31:610–616 11. Shang H, Xue Y, Liu Y, et al. Modified internal mandibular distraction osteogenesis in the treatment of micrognathia secondary to temporomandibular joint ankylosis: 4-year follow-up of a case. J Craniomaxillofac Surg 2012;40:373–378 12. Wysocki J, Reymond J, Krasucki K. Vascularization of the mandibular condylar head with respect to intracapsular fractures of mandible. J Craniomaxillofac Surg 2012;40:112–115 13. Long X, Goss AN. Pathological changes after the surgical creation of a vertical intracapsular condylar fracture. Int J Oral Maxillofac Surg 2007;36:834–837 14. Choi IH, Ahn JH, Chung CY, et al. Vascular proliferation and blood supply during distraction osteogenesis: a scanning electron microscopic observation. J Orthop Res 2000;18:698–705 15. Norholt SE, Jensen J, Schou S, et al. Complications after mandibular distraction osteogenesis: a retrospective study of 131 patients. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;111:420–427
© 2015 Mutaz B. Habal, MD
Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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Modified Condylar Distraction Osteogenesis via Single Preauricular Incision for Treatment of Temporomandibular Joint Ankylosis Jie Xu, PhD,* Xing Long, DDS, PhD,* Andrew Hua-an Cheng, BDS, MBBS,† Hengxing Cai, PhD,* Mohong Deng, PhD,* and Qinggong Meng, PhD* Background: Temporomandibular joint (TMJ) ankylosis with facial asymmetry is still controversial to deal with. This study describes a modified condylar distraction osteogenesis protocol via preauricular approach for the treatment of this condition. Methods: From 2006 to 2013, 18 patients with TMJ ankylosis were enrolled. The Wuhan TMJ Ankylosis treatment protocol includes as follows: (1) preauricular approach is the only surgical access; (2) TMJ arthroplasty is used to recontour the condylar head, and the vertical height of condyle is maintained; (3) distractor placement with distractor port exiting via preauricular incision; (4) distraction after 5 to 7 days of latency period with 0.5 mm twice daily; and (5) distractor removal after 3-month consolidation through preauricular incision. All patients had clinical follow-up and detailed examination. Results: All patients had satisfactory results postoperatively. The mean (range) mouth opening increased from 7.1 (0–18) to 32.1 (28–43) mm during 37 (6–81) months of follow-up period (P < 0.01). Facial asymmetry was corrected in all patients, and all patients had minimal postoperative scar perception of the preauricular incision. Conclusions: The Wuhan TMJ ankylosis protocol provides a safe and effective treatment alternative in managing TMJ ankylosis, especially in young women who are anxious about perceptive extraoral scar. Key Words: TMJ ankylosis, distraction osteogenesis, preauricular incision (J Craniofac Surg 2015;26: 509–511)
T
emporomandibular joint (TMJ) ankylosis is an uncommon condition in developed countries. However, it is still a common condition that affects patients in developing countries. Trauma and infection are the main causes of this devastating condition.1 Functionally, TMJ ankylosis severely restricts patient's mouth opening and causes difficulty in speech, mastication, and oral hygiene. Structurally, ankylosed TMJ often results in mandibular deformity,
From the *Department of Oral and Maxillofacial Surgery, The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine, Ministry of Education, School & Hospital of Stomatology, Wuhan University, Hubei, P.R. China; and †Oral and Maxillofacial Surgery Unit, Royal Adelaide Hospital, Adelaide, Australia. Received June 2, 2014. Accepted for publication July 31, 2014. Address correspondence and reprint requests to Xing Long, DDS, PhD, Key Laboratory of Oral Biomedical Engineering of Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan 430079, P.R. China; E-mail: [email protected] The authors report no conflicts of interest. Copyright © 2015 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001291
facial asymmetry, and obstructive sleep apnea in growing patients. Release of ankylosis, restoration of functional ramus height, and long-term maintenance of TMJ mobility are important elements of TMJ ankylosis management. Bone graft,2 alloplastic TMJ replacement,3 and distraction osteogenesis4 (DO) were all documented treatment modalities for the treatment of TMJ ankylosis with facial asymmetry. In recent years, DO has become an established treatment modality in treating TMJ ankylosis. The DO has the advantages of avoiding donor-site morbidity, gradual soft tissue adaptation, and predictable bone lengthening.5 Kaban et al6 has documented the Massachusetts General Hospital TMJ Ankylosis Protocol, which is a 7-step protocol. The protocol involves aggressive resection, coronoidectomy, lining of articular surface with temporalis flap or remaining TMJ disc, DO/ costochondral graft, early mobilization, and aggressive physiotherapy. It is a well-established protocol, but arthroplasty has been reported by other authors in releasing TMJ ankylosis.7 It reduces the amount of the condylar/ramus height that needed to be restored with DO. The Kaban protocol also requires a combination of preauricular and submandibular incisions. The extraoral incisions in the Chinese population often result in hypertrophic or keloid scarring. Many of the patients who seek reconstruction of TMJ ankylosis were young women who are concerned about postoperative scar. The distractor removal is often difficult, if not impossible, with the current condylar distraction protocol. Therefore, we present the Wuhan TMJ Ankylosis Protocol and its results of 18 cases using modified arthroplasty and condylar DO via preauricular incision.
MATERIALS AND METHODS From 2006 to 2013, 18 patients (7 women and 11 men) with TMJ ankylosis who presented to the Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, China, were enrolled into this study. All patients have been given informed consents, and the treatment protocol and study design were approved by the ethics committee of the School and Hospital of Stomatology, Wuhan University. There were 13 unilateral and 5 bilateral TMJ ankylosis cases in the study. Fifteen patients with TMJ ankylosis had previous mandibular trauma, and the other 3 patients had no clear identifiable cause for their TMJ ankylosis. The patients were aged 15 to 36 years (mean, 20.4 y). All patients had preoperative and postoperative clinical examination, radiographs, and CT scan. All patients were followed up with a postoperative regimen for a mean of 37 months (range, 6–81 mo).
Surgical Technique The patient was anesthetized and intubated with nasoendotracheal tube. The affected TMJ was exposed with preauricular incision as described by Al-Kayat and Bramley.8 The lateral aspect of the ankylosed bony mass was osteotomized and removed with saw and bur to expose the junction between the condyle and glenoid
The Journal of Craniofacial Surgery • Volume 26, Number 2, March 2015
Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
509
The Journal of Craniofacial Surgery • Volume 26, Number 2, March 2015
Xu et al
fossa. The condyle and glenoid fossa were carefully separated with a combination of osteotome and periosteal elevator. The medial aspect of the mandibular condyle and glenoid fossa could be inspected and recontoured, respectively, to form a new joint articulation. The ipsilateral coronoidectomy was performed to increase interincisal distance. If the mouth opening was not more than 30 mm, then contralateral coronoidectomy was performed if necessary. If there was a residual disk that can be identified, the disk should be repositioned and sutured to the lateral TMJ capsule. The distraction vector was determined by the direction of the mandibular posterior border. A distractor (Ningbo Cibei, China) was chosen and fixated parallel to the posterior border of mandible. The distractor was positioned to have the distractor port exiting through the preauricular incision (Fig. 1). Osteotomy of the condylar stump was made at the level of sigmoid notch after the positioning of distractor. The length of the condylar stump needed to be greater than 10 mm to ensure adequate bulk. The osteotomy was perpendicular to the posterior border of mandible. The distractor port was protected with a plastic tube to facilitate postoperative drainage and also make the activation of distractor port less painful. The tube was secured with nylon skin suture and removed when distraction protocol is completed. Mouth opening exercise was recommended on the third day postoperatively. After the latency period of 5 to 7days, the device was activated at a rate of 0.5 mm twice daily. The condylar stump was distracted until the correction of midline deviation was achieved. In bilateral cases, the distraction was completed when the desired vertical mandibular height was achieved. Weekly postoperative panoramic radiograph was taken during the distraction period. The distractor was maintained in situ as an internal fixator during the consolidation phase for at least 3 months. After 3-month consolidation, conventional helical CT was used to evaluate the extent of ossification of the distraction site. Removal of the distraction device was achieved using the same preauricular incision. In some cases, pseudo disks were found between condyle and fossa (Fig. 2).
RESULT The clinical characteristics and outcomes of patients were summarized. A total of 18 patients were enrolled, and all patients had satisfactory results postoperatively (Fig. 3). The mean (range) mouth opening significantly increased from 7.1 (0–18) to 32.1 (28– 43) mm in 37 (6–81) months of follow-up (P < 0.01). Mean (range) length increase by DO was 12.3 (6.8–21) mm. Facial asymmetry was corrected, and mean (range) length increase from condyle to
FIGURE 1. Osteotomy line was made at the condyle neck, and the distractor was reversed with its port exiting through the preauricular incision.
510
FIGURE 2. Between the new condyle and the fossa, a pseudodisk was found during the operation for removal of distractor (arrow).
mandibular notch was 10.7 (6–17) mm (P < 0.01) (Fig. 4). Preauricular scar was inconspicuous for all patients (Fig. 5). No patients complained about excessive pain at the distraction site. The only complication was distractor breakage in 1 patient that resulted in poor ossification at the distraction site. This was due to patient's noncompliance to nonchew hard diet during the 3-month consolidation period.
DISCUSSION In our study cohort, skin scars had been unconspicuous in all patients. No patient complained about the facial scarring. The incidence of postoperative facial scarring is usually not clearly documented. In a study of retromandibular approach for open reduction and internal fixation of condylar neck fracture, Ellis et al9 documented 7.5% of facial scarring rate. The authors would agree that the incidence of hypertrophic scar is higher in the Chinese population compared with that in the whites.10 The scarring often creates psychologic stress in patients who already experience significant facial deformities. A carefully designed and executed preauricular incision can minimize troublesome facial scarring. It is an obvious treatment alternative in treating patients with TMJ ankylosis who are anxious about postoperative unsightly scars. The arthroplasty technique of TMJ ankylosis release reduces the amount of dead space that is within the affected TMJ. The amount of bone that is needed to be regenerated from DO is significantly reduced. The lateral TMJ capsule and remaining TMJ disk can be used as sufficient liner of the glenoid fossa. In patients who had multiple operations, temporalis myofascial flap might be the only remaining option for lining the glenoid fossa. The positioning of the distractor is the major difference between the Wuhan protocol and other technique. First, the distractor is positioned at the sigmoid notch level along the posterior mandibular border. This is because the arthroplasty enables the osteotomy site to be carried out at the level of sigmoid notch. It is impossible
FIGURE 3. A, Bony mass was observed at the right condylar head, resulting in bony ankylosis. B, Osteotomy was made at the level of sigmoid notch. C, Cessation of distraction when the correction of midline deviation was achieved. D, Bone formation at the distraction gap 3 months after removal of distractor.
© 2015 Mutaz B. Habal, MD
Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 26, Number 2, March 2015
FIGURE 4. Chin midline was deviated preoperatively (A) or before distraction (B). Chin midline coincided with the maxillary midline postoperatively (C).
to achieve if a gap osteotomy was used to release the ankylosis. The modification enables and simplifies the fixation of the distractor via a preauricular incision. The distractor port is positioned in such a way that it exits via the preauricular incision. The capsular soft tissue around the foot plates of distractor is carefully approximated to reduce the chance of postoperative infection. Removal of distractor at the end of the consolidation period is another clinical problem that the surgeon encounters. The condylar stump is transported into the glenoid fossa and cannot be retrieved through a submandibular incision.11 By using the Wuhan protocol, all plates and screws can be exposed and removed via the same incision. This is a major modification from other studies because the superior foot plates are often left in situ because of access difficulty. The plastic tubing around the distractor port allows adequate drainage of the potential hematoma, which reduces the chance of developing a fibro-osseous ankylosis in the short term.7 However, early mobilization and continuous mouth opening exercise are also important in reducing reankylosis rate. The blood supply to condyle requires special consideration in managing any TMJ surgical pathology. The inferior alveolar artery and small arteries of the TMJ capsule form a complex capillary network that supplies the condylar head. The vessels penetrate the capsule in various locations and forms branches within the capsule and within the periosteum.12 Resorption, aseptic osteomyelitis, and necrosis of the condylar head are the most common postoperative complications when the surgical approach compromises the delicate TMJ blood supply.13 Using scanning electron microscope, Choi et al14 demonstrated vasculature within the bone and periosteum, which forms anastomosis at the distraction site. The vascular network can also supply the condylar stump during distraction period. In this
FIGURE 5. Facial asymmetry was significantly corrected in lateral view (A, D) or anterior view (B, E), preauricular scar was inconspicuous (D, E), and mouth opening increased significantly from 1.3 to 3.5 cm (C, F) after 6 months of follow-up.
Modified Condylar DO for TMJ Ankylosis
series, there was no adverse TMJ condylar head complication; the authors postulated that careful preservation of the medial pterygoid and masseter muscle attachment can be achieved using this technique. The ankylosis site and medial aspect of the ankylosis can be accessed without difficulty. The common dreaded complication of DO is infection around the distraction device. Norholt et al15 reported 12% of infection rate at the distraction site. However, the cohorts in this study did not have any postoperative infection. In this study, the only 1 case with distractor breakage is due to noncompliance to the nonchew hard diet protocol. This highlighted the importance of preoperative patient selection and patient education. Careful treatment planning, surgical execution, and meticulous postoperative care are all essential in the management of such patients.
CONCLUSIONS The Wuhan TMJ Ankylosis Protocol is a safe and effective treatment alternative in the management of TMJ ankylosis with facial asymmetry, especially in young female patients who are anxious about postoperative scars.
REFERENCES 1. Atac MS, Cakir M, Yucel E, et al. Early treatment of unilateral temporomandibular joint ankylosis: a multidisciplinary approach. J Craniofac Surg 2014;25:e213–e216 2. Kummoona R. Temporomandibular joint reconstruction with a 2-part chrome-cobalt prosthesis, chondro-osseous graft, and silastic: clinical and experimental studies. J Craniofac Surg 2009;20:2125–2135 3. Cascone P, Gennaro P, Gabriele G, et al. Functional outcomes in bilateral temporomandibular joint ankylosis treated with stock prosthesis. J Craniofac Surg 2013;24:E139–E141 4. Singh DJ, Glick PH, Bartlett SP. Mandibular deformities: single-vector distraction techniques for a multivector problem. J Craniofac Surg 2009;20:1468–1472 5. Pereira MA, Luiz de Freitas PH, da Rosa TF, et al. Understanding distraction osteogenesis on the maxillofacial complex: a literature review. J Oral Maxillofac Surg 2007;65:2518–2523 6. Kaban LB, Bouchard C, Troulis MJ. A protocol for management of temporomandibular joint ankylosis in children. J Oral Maxillofac Surg 2009;67:1966–1978 7. Long X, Li X, Cheng Y, et al. Preservation of disc for treatment of traumatic temporomandibular joint ankylosis. J Oral Maxillofac Surg 2005;63:897–902 8. Al-Kayat A, Bramley P. A modified pre-auricular approach to the temporomandibular joint and malar arch. Br J Oral Surg 1979;17:91–103 9. Ellis E III, McFadden D, Simon P, et al. Surgical complications with open treatment of mandibular condylar process fractures. J Oral Maxillofac Surg 2000;58:950–958 10. Li-Tsang CW, Lau JC, Chan CC. Prevalence of hypertrophic scar formation and its characteristics among the Chinese population. Burns 2005;31:610–616 11. Shang H, Xue Y, Liu Y, et al. Modified internal mandibular distraction osteogenesis in the treatment of micrognathia secondary to temporomandibular joint ankylosis: 4-year follow-up of a case. J Craniomaxillofac Surg 2012;40:373–378 12. Wysocki J, Reymond J, Krasucki K. Vascularization of the mandibular condylar head with respect to intracapsular fractures of mandible. J Craniomaxillofac Surg 2012;40:112–115 13. Long X, Goss AN. Pathological changes after the surgical creation of a vertical intracapsular condylar fracture. Int J Oral Maxillofac Surg 2007;36:834–837 14. Choi IH, Ahn JH, Chung CY, et al. Vascular proliferation and blood supply during distraction osteogenesis: a scanning electron microscopic observation. J Orthop Res 2000;18:698–705 15. Norholt SE, Jensen J, Schou S, et al. Complications after mandibular distraction osteogenesis: a retrospective study of 131 patients. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;111:420–427
© 2015 Mutaz B. Habal, MD
Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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