PRAME is a useful marker for the differential diagnosis of melanocytic tumours and histological mimics.

AIMS: Although the morphological assessment of melanoma is generally straightforward, diagnosis can be especially difficult when the significant morphological and immunohistochemical results overlap with those of benign and malignant melanocytic tumours and histological mimics. This study assessed the potential diagnostic utility of measuring PReferentially expressed Antigen in MElanoma (PRAME) immunohistochemically in naevi, melanomas and clear cell sarcomas (CCSs) in Chinese patients. METHODS: We examined the immunohistochemical expression of PRAME in 317 melanocytic naevi, 178 primary melanomas, 72 metastatic melanomas and 19 CCSs and compared the sensitivity and specificity of PRAME immunohistochemistry (IHC) in the differential diagnosis of melanocytic tumours and histological mimics. RESULTS: Of the 317 melanocytic naevi, 98.1%were completely negative for PRAME; six cases showed focal PRAME immunoreactivity in a minor population of lesional melanocytes. Diffuse nuclear immunoreactivity for PRAME was found in 89.9% of primary melanomas and 93.1% of metastatic melanomas. Regarding melanoma subtypes, PRAME was expressed in 100% of superficial spreading melanomas, 100% of melanomas arise in congenital naevus, 91.4% of nodular melanomas, 87.8% of acral lentigo melanomas, 80.0% of lentigo malignant melanomas, 60.0% of Spitz melanomas, 96.2% of mucosal melanomas and 80.0% of uveal melanomas. None of the two desmoplastic melanomas expressed PRAME. Of the 19 CCS cases, 89.5% were negative for PRAME and 10.5% showed focal weak PRAME immunoreactivity in a minor population of tumour cells. CONCLUSIONS: Our findings indicate that PRAME may be a useful marker to support a suspected diagnosis of melanoma. In addition, lack of PRAME expression is a valuable hint to CCS in a suspected case, and then molecular confirmation of the presence of EWSR1 rearrangement is necessary.

[Influence of bilateral coronoidectomy on temporomandibular joint stress distribution after costochondral graft reconstruction: a finite element analysis].

PURPOSE: To explore the effect of bilateral coronoidectomy on stress distribution after reconstruction of temporomandibular joint (TMJ) by costochondral graft. METHODS: Ten groups of models were established to simulate costochondral graft reconstruction with simultaneously different distances (0, 2, 4, 6, 8 mm) of mandibular advancement, with or without coronoidectomy. Force and stress distribution in the rib-cartilage area were analyzed by finite element analysis. RESULTS: In the process of bilateral joint reconstruction with simultaneously mandible advancement ranging from 0 mm to 8 mm, when the coronoid processes were retained, the forward deformation of the cartilage occurred and the shear force decreased in turn, from 113.2 N to 26.7 N on the left side and from 133.7 N to 1.9 N on the right side. When the coronoid processes were removed, the cartilage deformed backward and the shear force increased successively, from 94.6 N to 188.5 N on the left and 70.1 N to 157.7 N on the right. The stress in the neck was obviously concentrated when mandible advanced 8 mm. CONCLUSIONS: Coronoidectomy has an important impact on stress distribution in the TMJ area, and keeping the coronoid process is beneficial to maintain the mechanical balance. Bilateral CCG reconstruction with coronoidectomy for lengthy mandible advancement (≥ 8 mm) may lead to prominent increase in shear force beyond CCG resistance, resulting in a costal-cartilage junction fracture.

Changes of the condylar position after modified disk repositioning: A retrospective study based on magnetic resonance imaging.

OBJECTIVE: This study aimed to explain the malocclusion resulting from the changes in condylar position after unilateral open disk repositioning surgery. STUDY DESIGN: Patients treated with unilaterally modified temporomandibular joint disk repositioning were reviewed. All patients underwent magnetic resonance imaging (MRI) before and immediately after surgery. Occlusion was checked, and the changes in the joint space and condylar position were measured by using MRI. The paired t test was used for analysis. RESULTS: Thirty-two patients were included in the final analysis. The incidence rates of the posterior open bite in the affected side were 100%, 87.5%, 71.9%, 9.4%, 3.1%, and 3.1% at 0, 3, and 7 days and 3 and 6 months, and at the last follow-up after surgery, respectively. Mean distances of the condylar movements were 2.67 and 0.32 mm in the affected joints and normal joints, respectively. There were significant differences for the anterior (P = .03), superior (P < .001), and posterior (P < .001) joint spaces of the affected joints as demonstrated by MRI. CONCLUSIONS: The joint spaces significantly increased postoperatively, in addition to the changes in condylar position in anterior and inferior movements, leading to posterior open bite; however, the position returns to normal 3 months after surgery. We concluded that disk repositioning, when done unilaterally, results in stable occlusion over time.

Can a Novel Surgical Approach to the Temporomandibular Joint Improve Access and Reduce Complications?

PURPOSE: This clinical study investigated whether the vascular-guided multilayer preauricular approach (VMPA) to the temporomandibular joint (TMJ) could improve access and decrease complications. PATIENTS AND METHODS: This retrospective evaluation consisted of a consecutive series of patients who underwent TMJ surgeries through the VMPA from January through December 2013. Patients with a history of TMJ surgery were excluded. Clinical data, including operating times, subjective complaints of incision scars, functional conditions of the auriculotemporal nerve and facial nerve, and other complications, were recorded and analyzed. All patients in this study were followed for at least 6 months. RESULTS: All patients (606 joints) had successful TMJ surgeries through the VMPA. All incisions healed favorably with an uneventful recovery. No patient developed permanent weakness of the facial nerve or other severe complications. CONCLUSION: The VMPA can provide direct access and favorable visibility to the TMJ region and yield good esthetic and functional results. The VMPA can be considered the approach of choice for common TMJ surgeries.

Primary intra- and juxta-articular vascular malformations of the temporomandibular joint: a clinical analysis of 8 consecutive patients.

OBJECTIVE: To analyze primary intra- and juxta-articular vascular malformations of the temporomandibular joint. PATIENTS AND METHODS: This study retrospectively reviewed eight patients (seven venous malformations and one lymphatico-venous malformation) who were treated for intra- or juxta-articular vascular malformations of the temporomandibular joint from November 2005 to January 2011. All patients underwent magnetic resonance imaging (MRI) preoperatively. RESULTS: According to MRI findings, vascular malformations involving TMJ could be divided into 3 types; homogenous, lacunar and mixed types. All patients underwent surgical resection, and the final clinical diagnoses were confirmed by postoperative histopathology and immunohistochemical examinations. All treated patients had no clinical or radiographic signs of recurrence. CONCLUSION: Owing to the lower incidence and nonspecific clinical presentations, preoperative diagnosis of vascular malformations involving the TMJ region is very difficult. The classification based on MRI manifestations is proposed first, then it may greatly help in the initial diagnosis. Surgical resection is considered the first option for these TMJ lesions with excellent results.

Pigmented villonodular synovitis of the temporomandibular joint with intracranial extension.

Pigmented villonodular synovitis is an uncommon benign tumor-like proliferative lesion with an undetermined origin. Involvement of the temporomandibular joint is uncommon. Although pigmented villonodular synovitis is a benign lesion, it can grow with an aggressive pattern, and it extends extra-articularly in most of the reported cases, about one-third of them exhibiting intracranial involvement. The authors reported an additional case of a 47-year-old woman with intracranial extension, who had a history of joint pain and trismus. The preoperative diagnosis was made with arthroscopy. The lesion was completely excised via preauricular approach and condylotomy. The bone defect was covered by the pedicled temporalis myofascial fat flap. The patient has been symptom-free for 40 months postoperatively.

Synovial chondromatosis of the tempromandibular joint: relationship between MRI information and potential aggressive behavior.

PURPOSE: To evaluate the types of synovial condromatosis (SC) of tempromandibular joint (TMJ) on MRI and their potential aggressive behavior. METHODS: 144 patients with pure SC of TMJ were included in. On MRI, 3 types of the lesion included loose body, homogeneous mass, and mixture of both loose body and homogeneous mass. Bony evaluations included 4 stages of erosion: without erosion, chondral breakdown, bony absorption and bony perforation. RESULTS: 47 (32.6%) cases were categorized in the type of loose body, 71 (49.3%) cases in the type of homogeneous mass, and 26 (18.1%) cases in the type of mixture. 80% of bony perforation belonged to the type of homogeneous mass and 20% belonged to the type of mixture. 2 patients were found recurrence. CONCLUSION: The types of homogeneous mass and mixture of both on MRI were more aggressive. Homogeneous mass with bony erosion on MRI had potential recurrence.

Post-infectious myositis ossificans in medial, lateral pterygoid muscles: A case report and review of the literature.

Myositis ossificans (MO) is a disease where heterotropic bone forms within a muscle or other type of soft tissue. MO is classified into two groups, MO progressiva and post-traumatic MO. It rarely occurs in the masticatory muscles and thus, only 20 cases involving the masticatory muscles have been reported since 2001. The majority of the reported cases occurred due to trauma, repeated injury or surgical manipulation. However, in a small number of cases, no specific traumatic event was identified as the cause of MO. To the best of our knowledge, this is the first case of post-infectious MO to be reported in the medial and lateral pterygoid muscles.

Osteochondroma of the mandibular condyle: a classification system based on computed tomographic appearances.

OBJECTIVE: The objectives of this study were to introduce the classification of osteochondroma of the mandibular condyle based on computed tomographic images and to present our treatment experiences. MATERIALS AND METHODS: From January 2002 and December 2012, a total of 61 patients with condylar osteochondroma were treated in our division. Both clinical and radiologic aspects were reviewed. The average follow-up period was 24.3 months with a range of 6 to 120 months. RESULTS: Two types of condylar osteochondroma were presented: type 1 (protruding expansion) in 50 patients (82.0%) and type 2 (globular expansion) in 11 patients (18.0%). Type 1 condylar osteochondroma presented 5 forms: anterior/anteromedial (58%), posterior/posteromedial (6%), medial (16%), lateral (6%), and gigantic (14%). Local resection was performed on patients with type 1 condylar osteochondroma. Subtotal condylectomy/total condylectomy using costochondral graft reconstruction with/without orthognathic surgeries was performed on patients with type 2 condylar osteochondroma. During the follow-up period, tumor reformation, condyle absorption, and new deformity were not detected. The patients almost reattained facial symmetry. CONCLUSIONS: Preoperative classification based on computed tomographic images will help surgeons to choose the suitable surgical procedure to treat the condylar osteochondroma.

Local resection of the mass to treat the osteochondroma of the mandibular condyle: indications and different methods with 38-case series.

BACKGROUND: Local resection of the mass was reported to treat the condylar osteochodroma in some cases. The purpose of this study was to evaluate the feasibility and the indications of the local resection. METHODS: In all, 47 patients with osteochondroma of the mandibular condyle were treated from January 2002 to March 2012. The decision to perform local resection depended on 2 factors: there was a stalk existing between the mass and the condyle, and the condylar surface was involved less than 1/2. RESULTS: Local resection of the mass was performed in 38 cases (80.1%). These masses were removed by 4 methods: direct removal (18 cases), pushed-out by a screw and steel wire (14 cases), excision in multiple pieces (3 cases), and temporary osteotomy of the zygomatic arch (3 cases). In the follow-up period, there was no recurrence. CONCLUSION: Local resection of the mass was a more conservative procedure to treat the solitary osteochondroma with a stalk.

Metastatic spread to the mandibular condyle as initial clinical presentation: radiographic diagnosis and surgical experience.

PURPOSE: Metastatic spread to the mandibular condyle is uncommon. The authors retrospectively evaluated a series of consecutive cases of condylar metastases presenting as the initial clinical event to increase awareness and provide a better understanding of this occurrence. PATIENTS AND METHODS: This study consisted of 6 cases of metastatic tumor of the mandibular condyle presenting as the initial clinical event from July 2004 to May 2011. Primary sites included the bladder, prostate, lung, penis, colon, and breast. In 3 cases, positron emission tomographic/computed tomographic scans were performed to detect the primary lesions, which stayed occult at presentation. Surgical removal of the metastatic condylar lesions was performed in 3 patients, and palliative therapy was provided to all patients except a patient with a solitary metastasis. RESULTS: Five patients developed disseminated systemic metastases and died within 12 months. Only the patient with a solitary metastasis stayed alive, without any sign or symptom of tumor recurrence or metastasis at the most recent follow-up visit. CONCLUSIONS: For adult patients without a history of cancer, metastasis should be taken into consideration when the mandibular condyle is irregularly disrupted. Positron emission tomography/computed tomography is effective for detecting occult malignant lesions, whereas surgery might be indicated only for a solitary condylar metastasis.

Synovial TGF-ß1 and MMP-3 levels and their correlation with the progression of temporomandibular joint osteoarthritis combined with disc displacement: A preliminary study.

Osteoarthritis (OA) is a slow progressing degenerative disease that affects the joints, including the temporomandibular joint. In the present study, transforming growth factor-ß1 (TGF-ß1) and matrix metalloproteinase 3 (MMP-3) in synovial fluid (SF) were examined in detecting cartilage synthesis and degradation in progression of temporomandibular joint osteoarthritis (TMJ OA) combined with disc displacement (DD) diseases. SF was obtained from 16 patients with TMJ OA combined with DD and 10 normal volunteers. TGF-ß1 and MMP-3 levels were measured by enzyme-linked immunosorbent assay. In addition, TMJ OA combined with DD was classified into three stages based on radiographic signs on the preoperative tomograms and surgical findings at operation, and different treatment options were administered according to the stages. SF from TMJs with TMJ OA combined with DD showed higher levels of TGF-ß1 and MMP-3 compared with the asymptomatic control TMJs. With the progression of TMJ OA combined with DD, TGF-ß1 levels in SF were lower, while MMP-3 levels in SF were significantly higher. In conclusion, these data suggest that MMP-3 is not only involved in the pathological destruction process of TMJ OA combined with DD initially, but also has a positive correlation with the degree of pathological changes. Furthermore, a significant increase of TGF-ß1 levels was found in the SF that were able to counteract the deleterious effects of MMP-3 at the early stage of TMJ OA combined DD, providing the scientific basis on repositioning displaced disc as early as possible for these patients.

[A primary application and evaluation of temporomandibular joint replacement with stock prosthesis].

PURPOSE: To evaluate the effect of total joint replacement in treatment of temporomandibular joint(TMJ) osteoarthropathy with stock prostheses. METHODS: Six female patients involving 10 joints (2 unilateral and 4 bilateral), with an average age of 59 years old, were involved in this study. Three patients (5 joints) were diagnosed as internal derangement in V stage depending on MRI, 3D-CT findings and clinical characteristics. The other 3 patients (5 joints) had histories of failed temporomandibular joint operation using costochondral graft or temporalis fascial flap. The maximal mouth opening was 1.9 cm on average (range, 1.0 to 2.9cm). All the joints were replaced with Biomet standard prosthesis under general anesthesia. RESULTS: The follow-up period was from 7 to 49 months (average, 17.5 months). All the operations were successfully performed. Heterotopic ossification happened in a bilateral case 1 year postoperatively. One patient with bilateral joint disease complained of severe uncomfortable feeling in the region of the ears and the temples, although there was no significant positive signs according to an ENT examination. Pain relief of the joint and mouth opening improvement were significant in 4 patients. No failure was noted secondary to infection or loosening of the prostheses. The occlusal relationship kept stable postoperatively in all cases. CONCLUSIONS: Total TMJ joint replacement with standard prosthesis is a good choice for TMJ reconstruction. It can significantly reduce joint pain and the mouth opening limitation resulted from osteoarthritis. Long-term result remains to be evaluated based on a long-term follow-up.

Malignant hemangiopericytoma of the condyle.

Hemangiopericytoma (HPC) is an uncommon vascular tumor arising from pericytic cells with variable malignant potential. Primary HPCs of the bone are extremely rare; however, involvement of the condylar process has not been reported. We presented a 21-year-old female patient with low-grade malignant HPC in the right mandibular condyle. Clinical examination and imaging findings revealed a well-defined soft mass, encapsulating the mandibular condyle from behind. The lesion and mandibular condyle were removed simultaneously; then, the costochondral graft was used to reconstruct the defect. Histopathologic examinations of the specimen confirmed the diagnosis. After 2 years of follow-up, the patient is free of disease, and mouth opening returned to normal.

Synovial chondromatosis in the inferior compartment of the temporomandibular joint: different stages with different treatments.

PURPOSE: To discuss a new classification and the treatment principles of synovial chondromatosis (SC) in the inferior compartment of the temporomandibular joint (TMJ). PATIENTS AND METHODS: Five cases of SC in the inferior compartment were treated in an open manner between January 2008 and May 2011. Each case had different clinical and radiologic aspects and was treated with different surgical therapies. SC in the inferior compartment of the TMJ is classified into 3 stages. All patients were evaluated by computed tomography, magnetic resonance imaging, and clinical manifestations preoperatively and postoperatively. RESULTS: There were 3 kinds of manifestation modes from radiologic findings. Case 1 was in stage 1, in which multiple loose bodies are noted without bony erosion. This patient was treated by removal of loose bodies and affected synovium. Case 2 was in stage 2, in which multiple calcified nodules were conglutinated to the condyle; the condyle was enlarged with pressure erosions. This patient was treated by condylectomy and reconstruction with costochondral graft. Case 3, case 4, and case 5 were all in stage 3, in which the condyle was destroyed as a result of pressure erosions or by direct bony invasion of the mass and the inferior surface of the disc was involved. These patients were treated by condylectomy together with discectomy, as well as reconstruction with costochondral graft and pedicled deep temporal fascial fat flap. No recurrence occurred. The height of the ramus and the occlusion were maintained in the same condition as preoperatively. CONCLUSIONS: Our new classification of SC in the inferior compartment of the TMJ can better guide clinical treatment.

Preauricular transcondylar approach for basal cell adenoma of parotid coexist with ganglion cyst of the ipsilateral temporomandibular joint.

The concurrence of 2 independent neoplasias in the ipsilateral parotid and the temporomandibular joint (TMJ) region was infrequently reported. In this article, we present a unique case characterized by the coexistence of a rare salivary gland tumor, basal cell adenoma, of the parotid gland with a ganglion cyst in the ipsilateral TMJ region. A special surgical procedure was also presented here using a modified preauricular incision and transcondylar approach for extracapsular dissection of both lesions. Previously published literature are about the traditional treatment of benign parotid tumors using partial or total parotidectomy with the preservation of facial nerve mainly via an S-shaped submandibular incision and approach. Here, for the first time, a special surgical method using preauricular transcondylar approach for this unique case of synchronous occurrence of parotid tumor and TMJ cyst is reported.

Synovial chondromatosis originally arising in the lower compartment of temporomandibular joint: a case report and literature review.

INTRODUCTION: More than 200 cases of synovial chondromatosis (SC) in the TMJ were reported. Most of SC described exclusively involved the upper compartment of the joint. SC originally arising in the lower compartment is rarely found. MATERIAL AND METHODS: This article presents a 50-year-old man with a slow growing, pain, preauricular swelling in left side and the limitation of mouth-opening. Panoramic radiograph, CT scans and MR images were taken. An arthroscopic examination and a surgical intervention were performed. RESULTS: Panoramic radiograph and CT scans didn't reveal the calcifying lesions in left TMJ region. Sagittal MR images and the arthroscopic examination demonstrated distinct nodules within an extremely expanded lower joint compartment and a normal position of the articular disc. All loose bodies and grossly abnormal synovium were removed. The diagnosis of SC was confirmed by histologic examination. CONCLUSION: MRI and arthroscopy may be helpful diagnostically. Removal of all involved synovium, and loose cartilaginous bodies may be required for adequate treatment.

Endoscopically assisted reconstruction of the mandibular condyle with a costochondral graft through a modified preauricular approach.

We describe our experience with reconstruction of the mandibular condyle with a costrochondral graft (CCG). We retrospectively evaluated 122 patients with diagnoses including osteoarthrosis, ankylosis, tumours, idiopathic condylar resorption, comminuted condylar fracture, and chronic osteomyelitis of the temporomandibular joint (TMJ). We used a modified preauricular approach and an endoscopically assisted technique. The grafts were followed-up by computed tomograms (CTs) and magnetic resonance (MR) examinations. All patients had successful reconstruction of the mandibular condyle with a CCG. No patient had permanent weakness of the facial nerve or any other severe complication. With its wide range of indications, the endoscopically assisted reconstruction of the mandibular condyle with a CCG through a modified preauricular approach can produce good aesthetic and functional results while reducing operating time and tissue damage.

[The clinical application of arthroscope-assisted reconstruction of the mandibular condyle with costochondral graft].

OBJECTIVE: This is a preliminary study of the endoscopic technique on open surgery. The purpose of this study is to introduce the use of endoscopic technique for the reconstruction of the condyle with costochondral graft through a preauricular incision. METHODS: 33 patients of temporomandibular joint diseases (n=49) underwent reconstruction of mandibular condyle with costochondral graft. After preparation of the recipient site through a preauricular incision, maxillo-mandibular fixation, and preparation of the costochondral graft, the graft was fixed to the lateral side of the mandible ramus under the supervision of arthroscope. RESULTS: All the patients had successful reconstruction of the condyle with costochondral graft without any severe bleeding or craniocerebral injury. CONCLUSION: This case series demonstrates the feasibility of endoscopic technique for the reconstruction of the condyle through a preauricular incision. It has the advantage of high efficiency, minimal postoperative morbidity, great patient comfort, and little appearance impairment. The endoscopic technique has a promising future.