Total Temporomandibular Joint Research Articles

Use of Alloplastic Total Joint Replacement of the Temporomandibular Joint of Growing Patients: A Scoping Review

Temporomandibular joint (TMJ) disorders pose unique challenges in pediatric patients undergoing craniofacial growth. Alloplastic total temporomandibular joint reconstruction (ATJR) techniques have emerged as promising solutions, offering immediate joint function and symptom relief. However, the efficacy and safety of ATJR in this population remain under scrutiny. This scoping review aims to comprehensively summarize the evolving literature on ATJR in growing patients with end-stage TMJ pathology. Our methodology adhered to PRISMA-ScR guidelines, identifying 9 relevant articles. The discussion emphasizes preoperative considerations, treatment selection criteria, and potential complications. While ATJR offers short-term benefits, concerns regarding long-term outcomes persist, necessitating further research. Collaboration among multidisciplinary teams is crucial for optimal patient care. Future research should focus on comparative efficacy and safety, refining treatment algorithms, and long-term follow-up to enhance outcomes and minimize complications in pediatric TMJ pathology.

Influence of preoperative anatomy and functional status on outcomes after total temporomandibular joint replacement with patient-specific endoprostheses: A retrospective cohort study.

Temporomandibular joint (TMJ) replacement may be indicated for various pathological conditions, and the type of condition can affect the surgical procedure and outcomes. The causes of limited range of motion after alloplastic TMJ replacement have not been extensively studied. The present study aimed to evaluate the impact of preoperative jaw anatomy and functional status on the immediate and long-term outcomes of total TMJ replacement using a two-component patient-specific TMJ endoprosthesis. This retrospective study included 31 patients who underwent total TMJ replacement surgery between 2016 and 2020. The main outcome variable was the maximal incisal opening (MIO) after treatment. Secondary outcome variables included MIO improvement and the presence and type of postoperative complications. The primary predictive variable was the preoperative initial MIO. Secondary predictive variables included sex, age, indications for TMJ replacement, preoperative occlusion, condition of the glenoid fossa and/or condyle, shortening of the mandibular ramus, sagittal mandible position, lateral chin deviation, shape of the coronoid process, and type of surgery. The mean preoperative MIO was 13.0 ±8.0 mm, while the mean MIO 1 month after surgery was 20.6 ±5.5 mm, which was not statistically significant. However, at a later follow-up, functional parameters showed a significant improvement (p = 0.003), with a mean MIO of 32.5 ±5.0 mm 3 years after surgery. Statistical analysis indicated that the initial mouth opening is the strongest predictor of long-term functional recovery after TMJ replacement. Postoperative complications occurred in 4 cases (12.9%) following patient-specific endoprosthesis (PSE) placement. The use of PSEs for TMJ replacement has enabled the restoration of anatomical relationships in complex clinical cases and an improvement in mouth opening. The preoperative MIO was the only factor that significantly influenced long-term functional outcomes.

Muscle and joint mechanics during maximum force biting following total temporomandibular joint replacement surgery

Total temporomandibular joint replacement (TMJR) surgery is the established treatment for severe temporomandibular joint disorders. While TMJR surgery is known to increase mouth-opening capacity, reduce pain and improve quality of life, little is known about post-surgical jaw function during activities of daily living such as biting and chewing. The aim of this study was to use subject-specific 3D bite force measurements to evaluate the magnitude and direction of joint loading in unilateral total TMJR patients and compare these data to those in healthy control subjects. An optoelectronic tracking system was used to measure jaw kinematics while biting a rubber sample for 5 unilateral total TMJR patients and 8 controls. Finite element simulations driven by the measured kinematics were employed to calculate the resultant bite force generated when compressing the rubber between teeth during biting tasks. Subject-specific musculoskeletal models were subsequently used to calculate muscle and TMJ loading. Unilateral total TMJR patients generated a bite force of 249.6 ± 24.4 N and 164.2 ± 62.3 N when biting on the contralateral and ipsilateral molars, respectively. In contrast, controls generated a bite force of 317.1 ± 206.6 N. Unilateral total TMJR patients biting on the contralateral molars had a significantly higher lateral TMJ force direction (median difference: 63.6°, p = 0.028) and a significantly lower ratio of working TMJ force to bite force (median difference: 0.17, p = 0.049) than controls. Results of this study may guide TMJ prosthesis design and evaluation of dental implants.

Effect of duration of preoperative pain on outcomes of total temporomandibular joint replacement

The purpose of the study was to determine whether the duration of preoperative pain affects outcomes of temporomandibular joint replacement (TMJR). Twenty-seven patients who underwent primary TMJR between 1 July 2020 and 31 October 2022 were retrospectively assessed for duration of preoperative pain, level of preoperative and postoperative pain on a visual analogue scale (VAS; 0, none; 10, severe), preoperative and postoperative range of motion (ROM), and net change in quality of life (much better, better, same, worse, much worse), reporting the longest available follow up for each patient. Surgical success was defined as postoperative pain of ≤4 and postoperative ROM of ≥30 mm, or net change (Δ) in ROM of ≥10 mm. Regression analyses evaluated associations between independent variables and postoperative pain and ROM. At a mean follow-up of 17.8 (SD: 6.8, range 3-32) months , pain (5.1, SD: 2.2, p < 0.001) and ROM (9.3 mm, SD: 8.0, p<0.001) significantly improved. Quality of life was much better in 16 patients, better in eight, the same in one, and worse in two. Longer duration of preoperative pain tended to be negatively associated with postoperative ROM (β = −0.27; 95% CI −0.6 to 0.0; p = 0.078) but was not associated with severity of postoperative pain. Surgical success was achieved in 23/27 patients. The successful group tended to have lower pain on VAS preoperatively (5.9, SD: 1.9) vs 7.5, SD: 1.3) and postoperatively (0.4, SD: 0.8 vs 4.8, SD: 2.6), and greater improvement in quality of life (much better: 14/23 vs 2/4). In conclusion, longer duration of preoperative pain tended to be associated with worse postoperative ROM following TMJR. Higher preoperative pain may be a predictor for unsuccessful surgery.

Novel Use of Virtual Reality and Augmented Reality in Temporomandibular Total Joint Replacement Using Stock Prosthesis

This technical innovation demonstrates the use of ImmersiveTouch Virtual Reality (VR) and Augmented Reality (AR)-guided total temporomandibular joint replacement (TJR) using Biomet stock prosthesis in 2 patients with condylar degeneration. TJR VR planning includes condylar resection, prosthesis selection and positioning, and interference identification. AR provides real-time guidance for osteotomies, placement of prostheses and fixation screws, occlusion verification, and flexibility to modify the surgical course. Radiographic analysis demonstrated high correspondence between the preoperative plan and postoperative result. The average differences in the positioning of the condylar and fossa prosthesis are 1.252±0.269mm and 1.393±0.335mm, respectively. The main challenges include a steep learning curve, intraoperative technical difficulties, added surgical time, and additional costs. In conclusion, the case report demonstrates the advantages of implementing AR and VR technology in TJR's using stock prostheses as a pilot study. Further clinical trials are needed prior to this innovation becoming a mainstream practice.

Stock versus custom-made joint prostheses for total temporomandibular joint reconstruction

Stock versus custom-made joint prostheses for total temporomandibular joint reconstruction

Survival of temporomandibular total joint replacement: A systematic review and meta-analysis.

Prosthetic total joint replacement has been incorporated as a treatment for complex temporomandibular disorder; however, the survival of those devices is unknown. To assess the survival rate of the total temporomandibular joint (TMJ) prothesis and their main causes of failure. An electronic search was conducted in eight databases until March 2023. Prospective studies reporting the survival rate of total TMJ prothesis with a minimum follow-up of 12 months were included. Studies with partial TMJ prostheses or those no longer available on the market were excluded. Two reviewers assessed the individual risk of bias using the JBI Systematic Reviews for Quasi-experimental studies tool. Meta-analysis of proportions was conducted to summarise the survival rate, using 95% confidence intervals (CI). The GRADE approach assessed the certainty of the body of evidence. Data from 320 patients were collected from six prospective studies. The number of prothesis losses varied from none to four. All studies presented sources of bias related to follow-up description of the patients. The follow-up time varied from 12 months to 21 years. In most of the studies, prosthesis failure occurred within the first 6 months after surgery due to infection. The overall survival of total TMJ protheses was 97% (95% CI: 95%; 99%), with low heterogeneity (I2 = 29%) and a very low certainty of evidence. TMJ total prosthesis apparently is a safe procedure with a high survival rate and the evidence is very uncertain and presents important sources of bias.

Is an extended alloplastic replacement (eTMJR) device an option for the management of mandibular defects involving the temporomandibular joint? - A prospective cohort study

The reconstruction of large mandibular deficits involving the temporomandibular joint (TMJ) can be challenging. Extended alloplastic total temporomandibular joint reconstruction (eTMJR) is one treatment option.This single center, prospective, long-term observational study evaluates the objective and subjective outcomes of 21 eTMJR subjects followed >5 years postoperatively. The long-term stability of the eTMJR was determined by collecting objective data (mandibular kinematics, contralateral surface electromyography (sEMG), maximum voluntary clenching (MVC)) and subjective oral health related quality of life (oHrQoL).Except for mandibular deviation on opening, the objective variables markedly improved. A statistically significant decrease was found for ipsilateral condylar hypermobility (P = 0.001), and an increase in bilateral MVC (ipsilateral P = 0.029, contralateral P = 0.015). The subjective outcomes 'diet consistency’ (P = 0.001) and 'physical distress' (P = 0.043) improved significantly.Based on the stability of the eTMJR devices over the study period, improved objective and subjective variables, eTMJR appears to be a safe and effective predictable management option for patients with large mandibular deficits including the TMJ.

Role of Temporomandibular Total Joint Replacement in Correction of Facial Deformities.

Individuals suffering from facial deformities experience esthetic, functional and social setback in their lives every day. These patients benefit greatly with single-stage temporomandibular joint replacement along with orthognathic surgical procedures to correct functional as well as esthetic components. Five individuals with facial deformities due to hemifacial macrosomia, fibrous dysplasia, idiopathic condylar resorption, ankylosis, etc., were treated with total joint replacement along with orthognathic surgical procedures for functional and esthetic correction. The customized temporomandibular joint was digitally custom designed, and the orthognathic procedures were virtually planned on NemoFAB software before performing the surgical procedure. Intraoperatively, the overall time was reduced considerably with minimal unpredictable complications. One-week postoperative computed tomographs were obtained and superimposed on preoperative virtual surgical planning which showed minimal discrepancy. Follow-up period of 18-30months was maintained for all the patients with stable results, minimal relapse and satisfactory functional abilities. Total joint replacement along with orthognathic procedure provides single-stage functional and esthetic corrections for the patients, considerably improving their quality of life. Precise preoperative surgical planning proves to be an indispensable step for achieving desired results with minimal margin of error and avoid any unseen complications during the surgical procedure.

Alloplastic temporomandibular joint replacement – past, present, and future: “Learn from the past, prepare for the future, live in the present.” Thomas S. Monson

Based on evidence from the orthopaedic, biomedical engineering, and oral and maxillofacial surgical literature, this paper discusses reported successes and failures of past alloplastic temporomandibular joint (TMJ) devices that have led to the development of present total temporomandibular joint replacement (TMJR) devices. The paper concludes with discussion of the ongoing research that will lead to future embodiment (materials, designs, and manufacture) advances in TMJR management of severe and debilitating end-stage TMJ disease, further improving patients’ mandibular function, form, and overall quality of life.

Computational modelling of the fossa component fixation associated with alloplastic total temporomandibular joint replacements

The alloplastic total temporomandibular joint (TMJ) replacement is a complex surgical approach to end-stage TMJ disorders. The fixation of TMJ prostheses remains a critical issue for implant design and performance. For the fossa component, it is generally considered to use fixation screws to achieve tripod stability. However, the fossa may still come loose, and the mechanism remains unknown. A computational framework, consisting of a musculoskeletal model for calculating muscle and TMJ forces, and a finite element model for the fossa fixation simulation, was developed. A polyethylene (PE) fossa with stock prosthesis design was analyzed to predict contact pressures at the fixation interfaces, and stresses/strains in the fossa implant and bone during the static loading of normal chewing bite and maximum-force bite. The predicted maximum von Mises stresses were 33 MPa and 44 MPa for the bone, 13 MPa and 28 MPa for the PE fossa, and 131 MPa and 244 MPa for the screws, for the normal and maximum bites, respectively; the peak minimum principal strain was in the range of -2514 ∼ -3545 με for the bone. The results show that the sufficient initial mechanical strength of the fossa component fixation can be established using the screws in combination with bone support. The functional loads applied through the prosthetic TMJ bearing can be largely transferred to supporting bone without causing high level stresses. Tightening fixation screws with a pretension of 100 N can reduce transverse load to the screws and help prevent screw loosening. Further research is recommended to accurately quantify the transverse load and its influence on screw loosening during dynamic loading, and the frictional properties at the bone-implant interface.

Cross-Sectional Study of Serum Metal Ions in Patients With Metal Implants in the Maxillofacial Region.

The purpose of the present study was to measure the serum metal ion levels (titanium, cobalt, chromium) in patients who have metal implants in the maxillofacial region. The investigators implemented a cross sectional study on patients treated with procedures requiring metal implants for management of maxillofacial trauma, fixation for orthognathic surgery, and total temporomandibular joint replacement (TJR). Inductively coupled plasma mass spectrometry was used as an analytical method to detect metal ions in serum samples. The study comprised of 50 patients who were divided into 4 groups- group I- total TJR (n = 18), group II- orthognathic (n = 8), group III- trauma (n = 8), and group IV- control (n = 16). The mean values of metal ions level were raised than the control group. The present study's results suggest a rise in serum metal ion levels after the metal implantation in maxillofacial region. None of the patients had any abnormal signs and symptoms due to raised metal levels. Further studies are warranted to correlate the serum metal ion levels and their clinical relevance.

Design and development of a patient-specific temporomandibular joint implant: Probing the influence of bone condition on biomechanical response.

Total temporomandibular joint (TMJ) replacement is widely recognized as an effective treatment for TMJ disorders. The long-term stability of TMJ implants depends on two important factors which are design concepts for fixation to anatomical locations in the mandible and bone conditions. Other factors include stress distribution, microstrain in the peri-implant, bone attributes like bone conditions leading to the clinical complications and failures. This study addresses these limitations by examining the influence of patient-specific design concepts and bone conditions on TMJ implant performance. Clinical evidences support the importance of implant design on healing ability. Previous studies have focused on achieving precise implant fit based on geometric considerations, however those published studies did not explore the impact of such. Against this perspective, the present study reports the extensive finite element analysis (FEA) results, while analyzing the impact of a newly designed patient-specific TMJ implant to address clinical complications associated with various bone conditions, particularly osteoporotic bone. In validating the FEA results, the performance of additively manufactured patient-specific TMJ implants was compared with designs resembling two commonly used clinically approved implant designs. By addressing the limitations of previous research and emphasizing the importance of bone conditions, the study provides valuable guidelines for the development of next-generation TMJ implants. These findings contribute to enhanced clinical outcomes and long-term success in the treatment of TMJ disorders.

Recent Advances in Temporomandibular Joint Surgery.

Temporomandibular disorders (TMDs) affect a high percentage of children and adults worldwide. Surgery may be indicated in severe or recalcitrant cases. Several recent advancements in TMD and temporomandibular joint (TMJ) surgery have elevated understanding and the ability to treat affected patients. We discuss recent advances in TMD epidemiology, juvenile idiopathic arthritis (JIA) of the TMJ, and surgical techniques and technologies. Technical advancements have been identified in TMJ arthroscopy, the treatment of TMJ subluxation and dislocation, and extended prosthetic total TMJ reconstruction (eTMJR). Overall, this review provides valuable insights into significant recent advancements in TMJ disorders and their surgical management.

Kinematics of the jaw following total temporomandibular joint replacement surgery

Total temporomandibular joint (TMJ) replacement surgery aims to improve mandibular function, reduce pain and enhance quality of life in patients suffering from end-stage TMJ disorders. Traditional post-operative jaw evaluation is carried out using measurement of maximum interincisal opening distance; however, this can correlate poorly to joint function. The present study aimed to evaluate three-dimensional (3D) jaw motion during border movements and chewing in unilateral total TMJ replacement patients and healthy controls. Motion analysis experiments were performed on six unilateral total TMJ replacement patients and ten age-matched healthy controls. Subject-specific motion tracking plates worn by each participant were registered to CT scans of each participant’s skull and mandible to enable anatomical mandibular kinematics measurement using an optoelectronic system. Participants performed 15 repetitions of maximal opening, protrusion, lateral excursions, and chewing cycles. Total TMJ replacement patients had significantly smaller incisal displacements at maximum mouth opening relative to the controls (median difference: 7.1 mm, p = 0.002) and decreased anterior translation of the prosthetic condyle (median difference: 10.5 mm, p = 0.002). When TMJ replacement subjects chewed using their contralateral molars, there was a significant increase in inferior condylar translation of the non-working condyle (median difference: 9.7 mm, p = 0.016). This study found that unilateral total TMJ replacement surgery was associated with mouth opening capacity within the range of healthy individuals, but reduced anterior movement of the prosthetic condyle and restricted protrusion and lateral excursions. The results provide future direction for prosthetic TMJ design to enhance postsurgical implant functionality and improve long-term clinical outcomes for prosthesis recipients.

Major clinical approaches of prefabricated and customized prostheses for the temporomandibular joint: a systematic review

Introduction: The temporomandibular joint (TMJ) is composed of dense fibrocartilage formed between the mandibular condyle and the temporal bone. The high collagen content of this disc provides great rigidity and durability. Osteoarthritis-like degenerative joint disease belonging to temporomandibular disorder (TMD) is a destruction of bone and cartilage with a consequent inflammation that enhances tissue destruction. As a treatment, the implantation of a total alloplastic TMJ prosthesis is an innovative approach to the treatment of TMD. There are two types of prefabricated (stock) and custom computer-aided design/computer-aided manufacturing (CAD/CAM) systems. Objective: The present study aimed to carry out a concise systematic review of the major clinical approaches of prefabricated and customized prostheses for the temporomandibular joint. Methods: The systematic review rules of the PRISMA Platform were followed. The search was carried out from February to May 2023 in the Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases, using articles from 2018 to 2023. Results and Conclusion: A total of 107 articles were found, 34 articles were evaluated and 19 were included and developed in this systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 21 studies with a high risk of bias and 15 studies that did not meet GRADE. It was concluded that the clinical results of the stock and CAD/CAM prostheses suggested major improvements in mouth opening and reduced pain as a result of the rehabilitation of temporomandibular joint function. The results showed comparable data for the two types of prosthesis design at 6 months postoperatively. Thus, both temporomandibular joint and custom implants work well despite the additional advantages of custom prostheses, along with increasing access to digital technology, which may result in custom devices dominating the market in total temporomandibular joint replacement systems.

Technical approaches and clinical outcomes of the treatment of temporomandibular dysfunction with prostheses: a systematic review

Introduction: Temporomandibular joint (TMJ) replacement is usually a last resort in the surgical treatment of end-stage joint disease. For all this gear to work efficiently, occlusion, articulation, musculature, ligaments, and psychological factors must be in complete harmony. As a treatment, implantation of a total alloplastic TMJ prosthesis. Objective: It was to demonstrate, through a systematic review, the main considerations and clinical outcomes of the treatment of temporomandibular disorders with different types of prostheses. Methods: The systematic review rules of the PRISMA Platform were followed. The search was carried out from February to April 2023 in the Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases, using articles from 2013 to 2023. Results and Conclusion: A total of 127 articles were found, 60 articles were evaluated and 31 were included and developed in this systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 12 studies with a high risk of bias and 33 studies that did not meet GRADE. Based on the results, temporomandibular disorders (TMD) treatment is diverse and depends on the type of disease, as well as the duration and subjective level of pain. Alloplastic reconstruction can be advantageous in obtaining a rapid improvement in symptoms and rapid rehabilitation of masticatory function. Treatment of functional TMD is commonly based on conservative therapy, including physical therapy, pain therapy, and splinting therapy. Depending on the severity of TMD, treatment varies according to the degree of surgical invasion. Thus, the TMJ prosthesis seems to be reserved for patients with persistent pain, bone or fibrous ankylosis, or osteomyelitis after primary closed or open treatment of mandibular condyle fractures. Quality of life, mouth opening, and daily eating improved significantly after total TMJ prosthesis.

Which comorbid conditions and risk factors affect the outcome of and progression to total temporomandibular joint replacement?

Surgery is an effective modality to reduce pain and increase range of motion (ROM) in TMJ disorders. The aim of this study was to determine which comorbidities and risk factors affect outcomes and progression to total joint replacement (TJR). A retrospective cohort study of patients who underwent TJR between 2000- 2018 at MGH was conducted. Primary outcome was successful vs unsuccessful surgery. Success was defined as pain score ≤ 4 and ROM ≥ 30 mm; failure was defined as lack of either or both. Secondary outcome was differences between patients undergoing TJR only (group A) and those undergoing multiple surgeries progressing to TJR (group B). 99 patients (82 females, 17 males) were included. Mean follow-up was 4.1 years; mean age at first surgery was 34.2 (range 14–71) years. Unsuccessful outcomes were associated with high preoperative pain, low preoperative ROM, and higher number of surgeries. Male sex favored successful outcome. 75.0% group A and 47.6% group B had successful outcome. Group B had more females, higher postoperative pain, lower postoperative ROM, and used more opioids compared to group A. High preoperative pain, low preoperative ROM, and more surgeries were associated with poorer outcomes and frequent opioid use.

Do Case Reports on Total Mandibular, Extended, and Bilateral Total Temporomandibular Joint Reconstruction Prostheses Adhere to the Surgical CAse REport Guidelines?

The Surgical CAse REport (SCARE) guidelines are a standardized format for reporting surgical cases. The aim of this study was to evaluate the completeness of case reports documenting alloplastic reconstruction of large craniomaxillofacial defects involving total mandibular, bilateral, and extended temporomandibular joint in major high-quality craniomaxillofacial journals, based on the SCARE guidelines. An extensive online search was performed according to the Priority Reporting Items for Systematic Reviews and Meta-Analyses statement in PubMed, Embase, Scopus, Google Scholar, and Dimensions databases to identify relevant case reports. Each selected case report was assessed on 16 topics (38 items) of the SCARE guidelines, using a scoring scale of "0" (No/noncompliance), "1" (Yes/compliance), and "2" (unclear). The completeness of reporting (COR) score was calculated as the ratio of "yes" responses to "total" (ie, yes+no+unclear) responses. Adequacy of case reporting was denoted by a COR score of 70% or more. A total of 35 case reports were selected, where the male to female patients ratio was 3:4 cases, mean±standard deviation (SD) age: 34.9±16.7years, mean±SD follow-up duration: 17.0±12.9months, and number of patients with left, right, and bilateral temporomandibular joint reconstruction prostheses were 16, 10, and 09, respectively. The mean±SD COR score for all 35 case reports and the individual item of the SCARE guidelines was 70.2±10.5% and 66.5±31.2%, respectively. The minimum and maximum COR score was found for "Keywords" (0.0%) and "Introduction" (100%) and "Clinical Findings" (100%), respectively. Adequate reporting was found for 20/35 (57%) case reports. This study revealed that case reports in major high-quality craniomaxillofacial journals suffer from insufficient reporting. Widespread adoption of available standards, such as SCARE guidelines, is proposed to improve the quality and robustness of case reporting.

Longitudinal surveillance of serum titanium ion levels in patients with indigenous 3D printed total temporomandibular joint replacement

The purpose of this longitudinal study was to surveil the serum titanium ion levels at various time intervals in patients with indigenous 3D-printed total temporomandibular joint replacement (TMJ TJR). The study was conducted on 11 patients (male: 8; female: 3) who had undergone unilateral or bilateral TMJ TJR. Blood samples were drawn preoperatively (T0), 3 months (T1), 6 months (T2), and 1 year (T3) postoperatively. Data were analyzed and a p value of < 0.05 was considered statistically significant. The mean serum titanium ion levels at T0, T1, T2, and T3 was 9.34 ± 8.70 µg/L (mcg/L), 35.97 ± 20.27 mcg/L, 31.68 ± 17.03 mcg/L, and 47.91 ± 15.47 mcg/L respectively. The mean serum titanium ion levels increased significantly at T1 (p = 0.009), T2 (p = 0.032), and T3 (p = 0.00) interval. There was no significant difference between unilateral and bilateral groups. Serum titanium ion continued to show increased levels till the last follow-up of 1 year. These initial serum titanium ion levels increase is due to the initial wear phase of the prosthesis which manifests over 1 year. Further studies with large sample sizes and long-term follow-ups are required to see the deleterious effect if any on the TMJ TJR.