Traumatic Traumatic Temporomandibular Joint Ankylosis Research Articles

Pathogenesis of traumatic temporomandibular joint ankylosis: a narrative review.

ObjectiveTo comprehensively review the literature and summarize the results from human and animal studies related to the possible causes and pathogenesis of traumatic temporomandibular joint ankylosis (TMJA).Materials and MethodsThe Google Scholar, Embase, and Web of Science databases were used to search for articles related to traumatic TMJA from 2011 to 2020. All articles were screened according to the inclusion and exclusion criteria, collected, and analyzed.ResultsNineteen relevant articles were collected. These articles were classified into three groups: predisposing and etiological factors, cellular studies, and molecular studies.ConclusionThe pathological mechanisms are similar between TMJA and nonunion hypertrophy. Aberrant structural and etiological factors as well as disordered cellular and molecular mechanisms might contribute to TMJA formation. Although preclinical and clinical data have provided new evidence on the pathogenesis of traumatic TMJA, the molecular mechanisms and biological events require further exploration.

The role of lateral pterygoid muscle in the traumatic temporomandibular joint ankylosis: A gene chip based analysis.

Traumatic temporomandibular joint ankylosis (TMJA) is a common disease and disorder of the temporomandibular joint (TMJ); however, its pathogenesis has yet to be completely elucidated. In the authors' previous studies, the lateral pterygoid muscle (LPM) was confirmed to exert a function in distraction osteogenesis (DO) during the healing of a condylar fracture, which resulted in the formation of excess bone. The aim of the present study was to investigate alterations in the expression of any associated genes via an Affymetrix GeneChip method. The traumatic TMJA model was fabricated by a condylar fracture in the TMJ area of sheep with either a dissected LPM (LPD) or normal (LPN). The untreated sheep served as a control. At 4- and 12 weeks post-surgery, the condylar zone was isolated to perform the gene chip analysis, which was performed according to a standard Affymetrix protocol. The validated genes were further evaluated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The gene chip analysis indicated that the LPN gene expression pattern was similar compared with the DO process, while LPD was similar to that of normal bone fracture healing. The validated genes were collagen type II α1 chain, C-type lectin domain family 3 member A, interleukin 1A, cartilage oligomeric matrix protein, chondromodulin (LECT1), calcitonin receptor (CALCR), transforming growth factor (TGF)-β1, Fos proto-oncogene (FOS), bone γ-carboxyglutamate protein and bone morphogenic protein (BMP)7, among which, BMP7, LECT1, CALCR and FOS were confirmed by RT-qPCR. In conclusion, the present study demonstrated that LPM exerts a DO effect during the pathogenesis of traumatic TMJA, which may provide a novel target for preventing TMJA.

A comparative study of different surgical methods in the treatment of traumatic temporomandibular joint ankylosis

Two different surgical methods for the treatment of unilateral traumatic temporomandibular joint (TMJ) ankylosis with a medially displaced residual condyle are described. Eighteen patients with unilateral traumatic TMJ ankylosis and a medially displaced residual condyle, treated between 2008 and 2013, were included in this study. Group A patients (n=10) were treated with an autogenous coronoid process graft (ACPG) for reconstruction of the mandibular condyle, while group B patients (n=8) were treated by lateral arthroplasty (LAP); a temporalis myofascial flap (TMF) was used as interpositional material in both groups. The long-term results of the two treatments were compared through postoperative computed tomography and clinical follow-up examinations. The two groups were compared in terms of the recurrence rate, facial pattern change, and improvement in maximum inter-incisal opening (MIO) using SPSS 18.0 software. All patients were followed up for 12–24 months. Two patients in group A (20%) had reankylosis; no reankylosis was observed in group B patients. Compared with the ACPG, LAP improved the facial pattern and MIO significantly (P<0.05). LAP is a feasible and effective surgical method for the treatment of unilateral traumatic TMJ ankylosis when the displaced residual condyle is bigger than one third of the condylar head.

Influence of the lateral pterygoid muscle on traumatic temporomandibular joint bony ankylosis.

BackgroundThe pathogenesis of traumatic TMJ ankylosis remains unclear. This study aimed to verify the role of the lateral pterygoid muscle in the pathogenesis of traumatic temporomandibular joint (TMJ) bony ankylosis.MethodsEight 6-month-old male sheep were used in this study. Bilateral TMJ osteotomies were performed to induce sagittal fractures of the mandibular condyle. The lateral one-fourth segment of the disc was removed to establish a model of TMJ bony ankylosis. Subsequently, the function of the left and right lateral pterygoid muscles was blocked (experimental group) or maintained (control group), respectively. At 12 weeks postoperatively, animals were sacrificed and TMJ complex samples were evaluated by gross observation, spiral computed tomography (CT), micro-CT, and histological examinations.ResultsGross observation revealed bony ankylosis in the control TMJs and fibrous adhesions in the experimental TMJs. Spiral CT and micro-CT demonstrated that, compared to the experimental group, the control group showed calcified callus formation in the joint space and roughened articular surfaces after new bone formation, which protruded into the joint space. Maximum mediolateral and anteroposterior condylar diameters were significantly larger in the control group than in the experimental group. Micro-CT also showed that the primary growth orientation of new trabeculae was consistent with the direction of lateral pterygoid traction in the control group, but not in the experimental group. Histological examination showed fibro-osseous ankylosis in the control group, but not in the experimental group.ConclusionsThe lateral pterygoid simulates the effects of distraction osteogenesis, which is an important factor in the pathogenesis of TMJ bony ankylosis during the healing of sagittal condylar fractures.

Imaging and histologic features of traumatic temporomandibular joint ankylosis.

We aimed to study the pathology underlying traumatic temporomandibular joint ankylosis (TMJA). Specimens from 10 patients with traumatic TMJA were categorized using the Sawhney classification and were decalcified and stained with hematoxylin-eosin, alcian blue/periodic acid-Schiff, alizarin red, and Masson stains. Immunostaining with anti-CD34 antibody was performed. Computed tomography and pathologic findings were compared. Ankylosed areas consisted of fibrocartilaginous tissues. Bone formation occurred by osteophyte extension from the osteochondral surface toward the mass center. Endochondral ossification and osteophyte proliferation, alone or simultaneously, participated in bony ankylosis. Sequestra in the cartilaginous ankylosis preferentially formed bony bridges. Newly formed capillaries participated in ossification from the bony surface of the bone-cartilage junction; bone formed around the capillaries. Osteoclasts were present at the capillary tips. Types II and III were cartilaginous-bony ankylosis, with similar components. Bony traumatic TMJA was formed by osteophyte proliferation and endochondral ossification.

Surgical Treatment of Traumatic Temporomandibular Joint Ankylosis With Medially Displaced Residual Condyle: Surgical Methods and Long-Term Results

We report a surgical method for the treatment of traumatic temporomandibular joint (TMJ) ankylosis with a medially displaced residual condyle and compare the long-term results with those obtained using different interpositional materials. From 2001 to 2009, 60 patients and 82 joints diagnosed with traumatic TMJ ankylosis with a medially displaced residual condyle were included in the present study. Lateral arthroplasty (LAP) was performed, and either the masseter muscle flap (MMF) or the temporalis myofascial flap (TMF) was used as interpositional material to fill the lateral space. The long-term results of these treatments were compared by performing postoperative computed tomography scans and clinical follow-up examinations. Of the 82 joints, 22 were treated with LAP, 28 with LAP and MMF, and 32 with LAP and TMF. Of the 60 patients, 38 (48 joints) participated in long-term follow-up (from 1 to 4 yr). Of the 11 joints treated with LAP, 4 (36.4%) developed reankylosis. Of the 17 joints treated with LAP and MMF, 3 (17.6%) developed reankylosis, and none of the 20 joints treated with LAP and TMF developed reankylosis. Compared with LAP alone, LAP with TMF significantly improved the maximal incisal opening during long-term follow-up. LAP can preserve the residual TMJ structure. The TMF is a reliable interpositional material in LAP for the prevention of reankylosis.

Traumatic Temporomandibular Joint Ankylosis: Our Classification and Treatment Experience

This article studies the classification of traumatic temporomandibular joint (TMJ) ankylosis based on coronal computed tomographic (CT) scan and presents our treatment experience in the TMJ division of Shanghai Ninth People's Hospital. From 2001 to 2009, 130 patients diagnosed with TMJ ankylosis were treated in the TMJ division. Among them, 84 patients with 124 joint injuries caused by trauma were treated first by our group of surgeons and were included in this study. All of them had CT scans, especially coronal reconstruction through the TMJ area before and after surgery. A new classification based on the coronal CT scan was proposed: type A1 is fibrous ankylosis without bony fusion of the joint; type A2 is ankylosis with bony fusion on the lateral side of the joint, while the residual condyle fragment is bigger than 0.5 of the condylar head in the medial side; type A3 is similar to A2 but the residual condylar fragment is smaller than 0.5 of the condylar head; type A4 is ankylosis with complete bony fusion of the joint. Our treatment protocol for type A1 ankylosis is fibrous tissue release or condylar head resection with costochondral graft (CCG) and temporalis myofascial flap (TMF). For type A2 and A3 ankylosis, the lateral bony fusion is resected, while the intact residual condylar fragment, displaced medially, is retained. We call it "lateral arthroplasty" (LAP). TMF or masseter muscle flap (MMF) is used as a barrier in the lateral gap between the TMJ fossa and the stump of the mandibular ramus. If the medial condylar fragment in type A3 ankylosis is too small to bear the load, it is resected with the bony mass. The joint is then reconstructed with CCG and TMF or MMF. For type A4 ankylosis, the bony fusion is completely removed and the joint is reconstructed with CCG and TMF or MMF. The result of the treatment was evaluated by CT scan and clinical follow-up. Among the 124 ankylotic joints, there were 14 type A1 ankylosis (11.3%); 43 type A2 ankylosis (34.7%); 46 type A3 ankylosis (37.1%); and 21 type A4 ankylosis (16.9%). Part of type A1, and all of type A2 and A3 ankylosis had the residual condylar head displaced medially, which accounted for 75% (93/124) of the TMJ ankylosis. Eighty-two joints (66.1%) had LAP treatment; 33 joints (26.6%) had CCG joint reconstruction; and 3 joints (2.4%) had TMJ fibrous tissue release. In our case, 1 joint (0.8%) had condylectomy and TMF; 3 joints (2.4%) with fibrous ankylosis had mouth opening treatment; and 2 joints had gap arthroplasty (1.6%). Forty-eight patients with 68 joints had long follow-ups from 10 months to 4 years. Among them, 4 of 17 joints reconstructed with CCG had reankylosis (23.5%), and 7 of 48 joints treated with LAP had reankylosis (14.6%). The new classification of TMJ ankylosis based on coronal CT scan is valuable in guiding clinical treatment. LAP with TMF is a good way to treat traumatic TMJ ankylosis when the medially displaced condylar head and disc are intact. CCG with TMF has a good result for type A4 ankylosis.

Preservation of Disc for Treatment of Traumatic Temporomandibular Joint Ankylosis

A new operating method was used to treat traumatic temporomandibular joint (TMJ) ankylosis, to restore the structure of the TMJ, to improve the secondary maxillofacial deformity, and prevent recurrence of TMJ ankylosis. Thirty-six patients (20 females, 16 males; aged 5 to 54 years old) with TMJ ankylosis type II or III of 1 to 16 years' duration, with a maximal mouth opening from 0 to 15 mm preoperatively participated. The new method was to separate bony fusion between condyle and glenoid fossa, remove the condylar fragment that displaced medially or anteroinferiorly, mobilize the remains of the disc over the condylar stump and suture it with articular capsule, and shave the surface of the condylar stump and glenoid fossa smooth. Follow-up was performed from 1 to 7 years postoperatively in 21 cases. No recurrences occurred in patients whose TMJ disc was retained during operation. Patients had an average maximal mouth opening of 33.7 mm postoperatively. An 11-year-old patient showed an improved facial symmetry after surgery. By restoring the normal structure of the TMJ and preservation of the disc, recurrence of traumatic TMJ ankylosis and facial deformity in younger patients can be prevented.