Bony Ankylosis Of Temporomandibular Joint Research Articles

YAP promotes the early development of temporomandibular joint bony ankylosis by regulating mesenchymal stem cell function

To explore the role of YAP, a key effector of the Hippo pathway, in temporomandibular joint (TMJ) ankylosis. The temporal and spatial expression of YAP was detected via immunohistochemistry and multiplex immunohistochemistry on postoperative Days 1, 4, 7, 9, 11, 14 and 28 in a sheep model. Isolated mesenchymal stem cells (MSCs) from samples of the Day 14. The relative mRNA expression of YAP was examined before and after the osteogenic induction of MSCs. A YAP-silenced MSC model was constructed, and the effect of YAP knockdown on MSC function was examined. YAP is expressed in the nucleus of the key sites that determine the ankylosis formation, indicating that YAP is activated in a physiological state. The expression of YAP increased gradually over time. Moreover, the number of cells coexpressing of RUNX2 and YAP—with the osteogenic active zone labelled by RUNX2—tended to increase after Day 9. After the osteogenic induction of MSCs, the expression of YAP increased. After silencing YAP, the osteogenic, proliferative and migratory abilities of the MSCs were inhibited. YAP is involved in the early development of TMJ bony ankylosis. Inhibition of YAP using shRNA might be a promising way to prevent or treat TMJ ankylosis.

IRE1α inhibits osteogenic differentiation of mouse embryonic fibroblasts by limiting Shh signaling.

This study aimed to investigate the effect of endoplasmic reticulum (ER) stress sensor inositol-requiring enzyme 1α (IRE1α) on the sonic hedgehog N-terminus (N-Shh)-enhanced-osteogenic differentiation process in mouse embryonic fibroblasts (MEFs). Osteogenesis of MEFs was observed by alkaline phosphatase (ALP) staining, alizarin red staining, and Von Kossa staining assays. Activation of unfolded protein response and Shh signaling were examined using real-time quantitative PCR and western blot assays. IRE1α-deficient MEFs were used to explore the effect of IRE1α on N-Shh-driven osteogenesis. N-Shh increased ALP activity, matrix mineralization, and the expression of Alp and Col-I in MEFs under osteogenic conditions; notably, this was reversed when combined with the ER stress activator Tm treatment. Interestingly, the administration of N-Shh decreased the expression of IRE1α. Abrogation of IRE1α increased the expression of Shh pathway factors in osteogenesis-induced MEFs, contributing to the osteogenic effect of N-Shh. Moreover, IRE1α-deficient MEFs exhibited elevated levels of osteogenic markers. Our findings suggest that the IRE1α-mediated unfolded protein response may alleviate the ossification of MEFs by attenuating Shh signaling. Our research has identified a strategy to inhibit excessive ossification, which may have clinical significance in preventing temporomandibular joint bony ankylosis.

Temporal gene expression profiling during early-stage traumatic temporomandibular joint bony ankylosis in a sheep model

BackgroundInvestigating the molecular biology underpinning the early-stage of traumatic temporomandibular joint (TMJ) ankylosis is crucial for discovering new ways to prevent the disease. This study aimed to explore the dynamic changes of transcriptome from the intra-articular hematoma or the newly generated ankylosed callus during the onset and early progression of TMJ ankylosis.MethodsBased on a well-established sheep model of TMJ bony ankylosis, the genome-wide microarray data were obtained from samples at postoperative Days 1, 4, 7, 9, 11, 14 and 28, with intra-articular hematoma at Day 1 serving as controls. Fold changes in gene expression values were measured, and genes were identified via clustering based on time series analysis and further categorised into three major temporal classes: increased, variable and decreased expression groups. The genes in these three temporal groups were further analysed to reveal pathways and establish their biological significance.ResultsOsteoblastic and angiogenetic genes were found to be significantly expressed in the increased expression group. Genes linked to inflammation and osteoclasts were found in the decreased expression group. The various biological processes and pathways related to each temporal expression group were identified, and the increased expression group comprised genes exclusively involved in the following pathways: Hippo signaling pathway, Wnt signaling pathway and Rap 1 signaling pathway. The decreased expression group comprised genes exclusively involved in immune-related pathways and osteoclast differentiation. The variable expression group consisted of genes associated with DNA replication, DNA repair and DNA recombination. Significant biological pathways and transcription factors expressed at each time point postoperatively were also identified.ConclusionsThese data, for the first time, presented the temporal gene expression profiling and reveal the important process of molecular biology in the early-stage of traumatic TMJ bony ankylosis. The findings might contributed to identifying potential targets for the treatment of TMJ ankylosis.

Incidental findings involving the temporomandibular joint on computed tomography and magnetic resonance imaging.

The temporomandibular joint (TMJ) is frequently imaged in head and neck computed tomography (CT) and magnetic resonance imaging (MRI) studies. Depending on the indication for the study, an abnormality of the TMJ may be an incidental finding. These findings encompass both intra- and extra-articular disorders. They may also be related to local, regional or systemic conditions. Familiarity with these findings along with pertinent clinical information helps narrow the list of differential diagnoses. While definitive diagnosis may not be immediately apparent, a systematic approach contributes to improved discussions between clinicians and radiologists and better patient management.

Traumatic temporomandibular joint bony ankylosis in growing rats.

The pathogenesis of traumatic temporomandibular joint (TMJ) bony ankylosis remains unknown. This study aimed to explore the pathogenesis of traumatic TMJ bony ankylosis in a rat model. Twenty-four 3-week-old male Sprague-Dawley rats were used in this study. Excision of the whole disc, the fibrocartilage damage of the condyle and glenoid fossa, and narrowed joint space were performed in the left TMJ of the operation group to induce TMJ bony ankylosis (experimental side). The right TMJ underwent a sham operation (sham side). The control group did not undergo any operations. At 1, 4, and 8weeks postoperatively, rats of the operation group were sacrificed and TMJ complexes were evaluated by gross observation, Micro-CT, histological examinations, and immunofluorescence microscopy. Total RNA of TMJ complexes in the operation group were analyzed using RNA-seq. Gross observations revealed TMJ bony ankylosis on the experimental side. Micro-CT analysis demonstrated that compared to the sham side, the experimental side showed a larger volume of growth, and a considerable calcified bone callus formation in the narrowed joint space and on the rougher articular surfaces. Histological examinations indicated that endochondral ossification was observed on the experimental side, but not on the sham side. RNA-seq analysis and immunofluorescence revealed that Matrix metallopeptidase 13 (MMP13) and Runt-related transcription factor 2 (RUNX2) genes of endochondral ossification were significantly more downregulated on the experimental side than on the sham side. The primary pathways related to endochondral ossification were Parathyroid hormone synthesis, secretion and action, Relaxin signaling pathway, and IL-17 signaling pathway. The present study provided an innovative and reliable rat model of TMJ bony ankylosis by compound trauma and narrowed joint space. Furthermore, we demonstrated the downregulation of MMP13 and RUNX2 in the process of endochondral ossification in TMJ bony ankylosis.

Outcomes of total joint alloplastic reconstruction in TMJ ankylosis

The purpose of this study was to evaluate subjective and objective outcomes in patients with temporomandibular joint (TMJ) ankylosis treated with TMJ alloplastic reconstruction (TMJR). All patients diagnosed with TMJ ankylosis that underwent TMJR at our institution between 2010 and 2019 were retrospectively reviewed. Patients were divided into 2 cohorts: bony and fibrous ankylosis. Subjective variables assessed were facial pain and headaches, TMJ pain, jaw function, diet, and disability. Objective variables assessed were maximum interincisal opening and lateral excursions. The Mann-Whitney test was employed to analyze subjective variables and an unpaired t-test was used to analyze the objective variables. P < .05 was considered statistically significant. Twenty-eight patients met the inclusion criteria (21 female, 7 male). The mean age at the time of surgery was 42 years, and the mean number of prior TMJ surgeries was 3. A total of 52 TMJRs were performed in the 28 patients, and the mean follow-up time was 46 months. All subjective variables were significantly improved, and the mean maximum interincisal opening increased from 16.9 mm to 37.25 mm. The results of the study demonstrate that TMJR is an effective and reliable method for the management of both fibrous and bony TMJ ankylosis.

Simultaneous Gap Arthroplasty and Distraction Osteogenesis in the Management of Unilateral Bony TMJ Reankylosis – A Case Report

Temporomandibular Joint ankylosis is the adhesion of the condyle of the mandible to the base of the skull. It is the most common cause of hypoplasia of the mandible and eventual facial asymmetry. This case report describes the management of unilateral bony re-ankylosis of temporomandibular joint after the failure of a costochondral graft in an eight-year-old girl. The management of temporomandibular ankylosis presents a major challenge due to its increased reoccurrence rate. In the present case, simultaneous gap arthroplasty and distraction osteogenesis were performed to separate the ankylotic mass and lengthen the ramus-condyle unit. The one year follow-up of the patient showed adequate mouth opening. We recommend concomitant gap arthroplasty and distraction osteogenesis for effectively managing temporomandibular joint bony ankylosis.

Long-term effects of autogenous coronoid grafts on the facial growth of children with unilateral temporomandibular joint ankylosis and reconstructed mandibular condyle

Mandibular condyle injury usually results in malocclusion and disharmony of facial growth in growing children. This study aimed to evaluate the long-term effects of autogenous coronoid grafts on the facial growth of children with unilateral temporomandibular joint (TMJ) ankylosis who underwent mandibular condyle reconstruction. Ten growing patients with unilateral bony TMJ ankylosis admitted in West China Hospital of Stomatology, Sichuan University between January 1st, 2008 and December 31st, 2016 were followed up and evaluated. These patients include three males and seven females with ages ranging from 5 years to 12 years at the time of surgery. Each patient underwent gap arthroplasty, condyle reconstruction with ipsilateral coronoid, and interposition of the pedicled temporalis fascial flap in a single operation. The postoperative follow-up ranged from 3 years to 8 years with an average of 4.9 years. Postoperative panoramic radiographs determined the growth of the mandibular height and length on the affected side and compared it with those of the healthy side. All patients recovered uneventfully after surgery. At the end of follow-up period, the maximal mouth opening ranged from 32 mm to 41 mm with an average of 35.6 mm. Mandibular height and length continued to grow after the successful treatment of ankylosis using autogenous coronoid grafts for condyle reconstruction. However, growth deficit still existed. The final ramus height and mandibular length of the affected side at the end of follow-up increased by 25.3% (P<0.05) and 26.1% (P<0.05), respectively, compared with the initial values measured immediately after surgery. Growth rates of ramus height and mandibular length of the affected side were 47.1% and 27.2% lower (P<0.05) than those of the healthy side, respectively. Mandibular height and length continued to grow after the successful treatment of ankylosis by using autogenous coronoid grafts for condyle reconstruction. However, growth deficit still existed. The growth rate of the affected mandible was reduced compared with that of the undisturbed side even after treatment of ankylosis.

Interpositional arthroplasty with temporalis myofascial flap reconstruction in a case of temporomandibular joint bony ankylosis: a case report and review of literature

The report describes the treatment of a 30 year old female patient having unilateral right temporomandibular joint (TMJ) bony ankylosis whose mouth opening was restricted to 5 mm and had additional mandibular retrognathism causing severe mastication problems besides speech difficulties and low morale. The ankylosis had resulted in facial asymmetry due to bony hard swelling in front of right tragus. The patient was taken up for right interpositional arthroplasty with temporalis myofascial flap reconstruction by pre auricular approach and left coronoidectomy by intraoral approach as a preferred technique. A satisfactory mouth opening of 33 mm was achieved in immediate post-operative. Patient was followed up with aggressive mouth opening exercises in postoperative period.

Reducing macrophage numbers alleviates temporomandibular joint ankylosis.

Temporomandibular joint (TMJ) ankylosis is a severe joint disease mainly caused by trauma that leads to a series of oral and maxillofacial function disorders and psychological problems. Our series of studies indicate that TMJ ankylosis development is similar to fracture healing and that severe trauma results in bony ankylosis instead of fibrous ankylosis. Macrophages are early infiltrating inflammatory cells in fracture and play a critical role in initiating fracture repair. We hypothesize that the large numbers of macrophages in the early phase of TMJ ankylosis trigger ankylosed bone mass formation and that the depletion of these macrophages in the early phase could inhibit the development of TMJ ankylosis. By analysing human TMJ ankylosis specimens, we found large numbers of infiltrated macrophages in the less-than-1-year ankylosis samples. A rabbit model of TMJ bony ankylosis was established and large numbers of infiltrated macrophages were found at 4days post-operation. Local clodronate liposome (CLD-lip) injection, which depleted macrophages, alleviated the severity of ankylosis compared with local phosphate-buffered saline (PBS)-loaded liposome (PBS-lip) injection (macrophage number, PBS-lips vs. CLD-lips: 626.03 ± 164.53 vs. 341.4 ± 108.88n/mm2; ankylosis calcification score, PBS-lips vs. CLD-lips: 2.11 ± 0.78 vs. 0.78 ± 0.66). Histological results showed that the cartilage area was reduced in the CLD-lip-treated side (PBS-lips vs. CLD-lips: 6.82 ± 4.42% vs. 2.71 ± 2.78%) and that the Wnt signalling regulating cartilage formation was disrupted (Wnt5a expression decreased 60% and Wnt4 expression decreased 73%). Thus, our study showed that large numbers of macrophages infiltrated during the early phase of ankylosis and that reducing macrophage numbers alleviated ankylosis development by reducing cartilage formation.

Association between maximum mouth opening and area of bony fusion in simulated temporomandibular joint bony ankylosis

The aim of this study was to investigate the quantitative association between active/passive maximum mouth opening (AMMO/PMMO) and the severity of simulated temporomandibular joint (TMJ) bony ankylosis. Twenty-eight male sheep were divided randomly and equally into surgical and control groups. Surgical group animals underwent bilateral TMJ osteotomy during which left lateral pterygoid muscle function was blocked. Control animals did not undergo surgery. Body weight, AMMO/PMMO, and TMJ morphological features were evaluated preoperatively and at 12 and 24 weeks post-surgery. In the surgical group, only the right TMJ complexes with maintained lateral pterygoid muscle function developed TMJ bony ankylosis. The AMMO/PMMO and end-feel distance in the surgical group were significantly lower than those in the control group (P < 0.001, both) at 12 and 24 weeks post-surgery. Moreover, AMMO (r = −0.940 and −0.952, P < 0.001, both) and PMMO (r = −0.944 and −0.953, P < 0.001, both) were negatively correlated with the area (mm2) of bony fusion post-surgery. These findings may be useful for the clinical treatment of early mandibular condyle fracture, with the use of occlusal pads/open-mouth plates to relax the lateral pterygoid muscle and block its function. When bony ankylosis developed in the TMJ, the greater the area of bony fusion, the more limited were AMMO/PMMO.

Gap arthroplasty with custom-made acrylic mouth opener

Ankylosis of temporomandibular joint (TMJ) involves the fusion of mandibular condyle to the base of the skull. When it occurs in a child, it can have devastating effects on the future growth, development of jaws and teeth, and also has a negative influence on the psychosocial development of the patient because of the obvious facial deformity, which worsens with growth. Impairment of speech and mastication, poor oral hygiene, caries, and compromise airway pose a severe psychological burden on the tender minds of children. Hereby, we present a case of 10-year-old female who reported with inability to open mouth, diagnosed with right bony TMJ ankylosis. The surgical approach consisted of gap arthroplasty followed by vigorous physiotherapy by custom-made acrylic mouth opener. The treatment of TMJ ankylosis poses a significant challenge because of technical difficulties and a high incidence of recurrence. It includes a team of oral and maxillofacial surgeons, pediatric dentist, and anesthetist.

Does Surgical Release of TMJ Bony Ankylosis Increase the Risk of Trigeminocardiac Reflex? A Retrospective Cohort Study

The exact frequency of the trigeminocardiac (TGC) reflex in temporomandibular joint (TMJ) surgery is still controversial. The purpose of the present report was to estimate the frequency of and identify the risk factors for TGC reflex among patients undergoing operative management of TMJ ankyloses. A retrospective cohort study was conducted of patients who had undergone gap arthroplasty for TMJ ankyloses at Al-Azhar University Hospital, Cairo, Egypt, from 2001 to 2015. The predictor variables were patient demographic data (age and sex), ankylosis type, and surgery type. The outcome variable was the occurrence of the TGC reflex (yes vs no). The data analysis included descriptive statistics and χ2 tests to compare the categorical variables. Binary regression logistic model analysis was performed to identify the associated predictor variable. P values were considered statistically significant at ≤ .05. The sample included 55 subjects. The mean±standard deviation age of the patients was 21.3±9.855years, and 43.6% were males. The frequency of TGC reflex was 12.7%. The factors associated with an increased risk of TGC reflex were type IV bony ankylosis (P=.012) and the need for repeat surgery (P=.016.). A multivariable binary regression model analysis demonstrated that the recurrence of surgery was the most significant predictor factor affecting the frequency of the TGC reflex. The computed variance ranged from 13 to 25%. However, other variables, including age, gender, side, and ankylosis type, were not associated with reflex onset (odds ratio, 0.028; 95% confidence interval, 0.001 to 0.911; P=.044). Recurrent ankylosis surgery carries a high risk of TGC reflex. Preoperative risk factor identification and close monitoring are crucial to prevent the occurrence of this reflex in susceptible patients. Future research projects should include more variables in the study.

The Safety and Accuracy of Surgical Navigation Technology in the Treatment of Lesions Involving the Skull Base.

As compared with the normal anatomy, structures of the skull base and its surroundings have been dramatically altered of the lesion near the skull base. How to remove the lesion at the skull base was mainly depending on surgeon's personal experience during past years. In this study, the authors explored the safety and accuracy of the surgical navigation system in resecting lesions near the skull base. The surgical cases consisted of 15 patients who underwent surgery involving the skull base with the using of surgical navigation technology. Five patients had adenoid cystic carcinoma at minor salivary glands of the palate extending to the skull base and 10 patients were suffered from bony ankylosis of temporomandibular joint. After the system converted patient's computed tomography scans into three-dimensional reconstructive images, preoperative planning and simulation of the operation process could be made by surgeons. During the operation, the virtual images were matched with the patient through individual registration. The system provided surgeon with feedback about the operation on the screen instantly with moving the navigated pointer. The application of surgical navigation system was safe and reliable for resecting the ankylotic bone and identifying the extent of tumors resection near the skull base. No complications including cerebrospinal fluid leak, cranial nerve injuries, severe bleeding happened to those patients. Given the safety and accuracy of the surgical navigation system, surgery near the skull base appeared to be an ideal field for using with its complex anatomy.

Changes in craniocervical angulation in patients with temporomandibular joint bony ankylosis

Changes in craniocervical angulation in patients with temporomandibular joint bony ankylosis

Assessment of the Effect of Temporomandibular Joint Bony Ankylosis on Eustachian Tube Functions

Objective: This study was designed to evaluate the effect of temporomandibular joint (TMJ) bony ankylosis on Eustachian tube (ET) functions. Subjects and Methods: Twelve patients suffering from TMJ bony ankylosis were selected from those attending the out-patient Clinic of Oral and Maxillofacial Surgery Department, Faculty of Oral and Dental Medicine, Cairo University. Twelve subjects (control group) underwent Eustachian tube function test were selected also. Tympanometry was utilized to assess Eustachian tube function. Three pressure reading (P1, P2, and P3) of the middle ear and external ear canal volume were recorded by the use of tympanometry. Comparisons were performed between patient and control group to evaluate the change of pressure. Results: Throughout the results, four ears showed type (C) tympanogram representing Eustachian tube dysfunction, two ears showed type (B) tympanogram which represent otitis media with effusion. While other ears showed type (A) tympanogram. On comparing the pressure values between the patients and the control, significant decrease was recorded in (P2) value in the patients group and no significant difference existed in the external canal volume. Conclusions: The Eustachian tube function is affected in patients of temporomandibular joint bony ankylosis, it cannot adapt to changes in pressure effectively. Patients of TMJ ankylosis are more liable to develop otitis media. Inflation-deflation test is a reliable method for evaluating Eustachian tube function in patients of (TMJ) ankylosis. The external ear canal volume was not affected in this group of patients.

Cephalometric evaluation of soft-tissue changes in the upper and lower lips and chin after gap arthroplasty for the correction of temporomandibular joint bony ankylosis

Cephalometric evaluation of soft-tissue changes in the upper and lower lips and chin after gap arthroplasty for the correction of temporomandibular joint bony ankylosis

Effect of Temporomandibular Joint Bony Ankylosis on Maxillary Sinus Wall Thickness

<i><span>Objectives:</span></i><span> </span><span>This study was designed to clarify the changes that might be induced in the maxillary sinus walls thickness in response to TMJ bony ankylosis</span><span> </span><i><span>Subjects and methods:</span></i><span> </span><span>Forty five </span><span>(45</span><span>) subjects were included in the study. They were divided into two groups Group I, (patients group) comprised</span><span> fifteen 15</span><span> patients were suffering from temporomandibular joint bony ankylosis (26 maxillary sinuses involved) and Group II, (control group) contained thirty (30) healthy volunteer.</span><span> Maxillary sinus walls thickness</span><span> has been measured by computerized tomography scan for both groups and was compared. </span><i><span>Results:</span></i><span> </span><span>There was significant increase in mean thickness of all walls of maxillary sinus in patients group. The thickness of lateral wall of recurrent cases of TMJ ankylosis showed significant de</span><span>crease when compared with the non-recurrent cases.</span><span> </span><i><span>Conclusion:</span></i><span> </span><span>Observable Increase in the thickness of maxillary sinus walls. This may be attributed to bone apposition from outer side without resorption from inner side. This explanation is ascribed to lack of pneumatization associated with hindrance of upper air way that usually existing with cases of TMJ bony ankylosis

Assessment of the effect of gap arthroplasty on serum interleukin-1β in patients with temporomandibular joint bony ankylosis

Assessment of the effect of gap arthroplasty on serum interleukin-1β in patients with temporomandibular joint bony ankylosis

Temporomandibular joint ankylosis

Trauma to the chin is the most common cause of temporomandibular joint (TMJ) ankylosis along with other causes which include infections and inflammatory destruction of the synovial lining of the joint. Inflammation of the joint may be primary resulting from infection of the joint itself or may result from extension of neighboring infection. The clinical features of ankylosis are limited mouth opening, with no pain and joint sounds, and marked deflection of the mandible to the affected side. This article highlights the clinical and radiographic features of TMJ bony ankylosis.