Will they fit? Determinants of the adaptability of stock TMJ prostheses where custom TMJ prostheses were utilized

Currently only two alloplastic temporomandibular joint (TMJ) total joint replacement (TJR) systems are available in the United States. The aim of this study was to define variables that determine whether a Biomet stock prosthesis could have been used to reconstruct a TMJ previously reconstructed with a TMJ Concepts patient-fitted prosthesis. All of the TMJ Concepts prostheses placed between 2010 and 2018 at the University of Texas – Health at San Antonio were analyzed retrospectively. There were 128 cases (241 joints) with intact stereolithographic models analyzed for successful adaptation of the Biomet stock TMJ prosthesis. Anatomical, demographic, etiological, and perioperative data were gathered for each joint to investigate possible causes of failure of stock adaptation. The majority of joints, 74% (178/241), could have had a stock prosthesis adapt. All joints with ≥40 mm gap arthroplasty failed stock prosthesis adaptation. Only 50% (32/64) of the joints with at least one previous open TMJ surgery and 60% (58/96) of the joints with concomitant orthognathic surgery could have had a stock TMJ prosthesis. The stock prosthesis could not be adapted for any of the patients requiring TMJ replacement for congenital disorders or those requiring TMJ salvage. Overall, the majority of cases treated with a patient-specific TMJ TJR could have been treated with a stock prosthesis.     

Temporomandibular joint reconstruction with total alloplastic joint replacement

This paper is a preliminary paper which presents the early findings of an ongoing prospective trial on the use of the TMJ Concepts and Biomet Lorenz total joint replacement systems for the reconstruction of the temporomandibular joint (TMJ). Total alloplastic replacement of the TMJ has become a viable option for many people who suffer from TMJ disease where surgical reconstruction is indicated. Degenerative joint diseases such as osteoarthritis, rheumatoid arthritis, psoriatic arthritis, TMJ ankylosis, malunited condylar fractures and tumours can be successfully treated using this technique. There are a number of TMJ prostheses available. Two of the joint replacement products, which have been found to be most reliable and have FDA approval in the United States, are the TMJ Concepts system and the Biomet Lorenz system, and for this reason they are being investigated in this study. This study presents the findings of seven patients with a total of 12 joint replacements using either the TMJ Concepts system or the Biomet Lorenz joint system. Two patients (3 joints) had the TMJ Concepts system and five patients (9 joints) had the Biomet Lorenz system. Although still early, the results were generally pleasing, with the longest replacement having been in position for three years and the most recent six months. The average postoperative mouth opening was 29.7 mm (range 25-35 mm) with an average pain score of 1.7 (range 0-3, minimum score of 0 and maximum 10). Complications were minimal and related to sensory disturbance to the lip in one patient and joint dislocation in two patients.     

Total alloplastic temporomandibular joint reconstruction using Biomet stock prostheses: the University of Florida experience

The purpose of this study was to report the subjective and objective outcomes of temporomandibular joint (TMJ) replacement with Biomet stock prostheses at a single institution in Florida. In this retrospective study, patients who underwent TMJ replacement using a Biomet stock prosthesis from 2005 to 2012 were analyzed. Subjective (pain, diet) and objective (maximal incisal opening) information was obtained. In addition, a quality of life measure was obtained pre- and postoperatively. Significance was set at <0.01. Thirty-six patients (26 bilateral, 6 left, and 4 right) who underwent TMJ replacement using a Biomet stock prosthesis were eligible for the study. Maximal incisal opening improved from 26.1 mm preoperatively to a mean of 34.4 mm postoperatively. The pain score decreased from 7.9 preoperatively to a mean of 3.8 postoperatively. Diet restriction decreased from 6.8 preoperatively to a mean of 3.5 postoperatively. Quality of life improved from a median of 4 preoperatively to a postoperative median of 2. Four implants were removed/replaced because of heterotopic bone formation, infection, and/or loose hardware. Follow-up ranged from 6 to 83 months. Overall, TMJ reconstruction using the Biomet stock joint is effective and safe in this patient population.     

A ten-year experience and follow-up of three hundred patients fitted with the Biomet/Lorenz Microfixation TMJ replacement system

The purpose of this paper is to present the postoperative results obtained after full temporomandibular joint (TMJ) reconstruction employing the Biomet/Lorenz Microfixation TMJ replacement system (Jacksonville, FL, USA) in 300 patients (201 unilateral, 99 bilateral). Objective data (maximum inter-incisal opening; MIO) and subjective data (function and speech, diet, and pain) were collected preoperatively and at postoperative evaluations performed over a 10-year period (mean 3.5, standard deviation 2.1 years). The MIO measures were obtained using a calliper rule. Subjective data were evaluated using a visual analogue scale with scores ranging from 0 to 5 for each variable. The results were analyzed with the paired t-test (two-sided, α = 5%). Each patient showed significant improvements for all of the variables at evaluation on postoperative day 7. The results for MIO, function and speech, and diet, showed improvements at each postoperative evaluation over a maximum of 3 years, with stabilization of the results from the fourth year. Complaints of pain decreased considerably up to the 1-month postoperative evaluation, and no patient reported severe pain at 6 months after surgery. The results presented show that the reconstruction of the TMJ through the installation of the Biomet/Lorenz system prosthesis is a safe and effective option for proper reestablishment of the joint and stomatognathic system function; significant long-term improvements in mandibular range of motion are promoted and pain levels decrease.     

标准型人工颞下颌关节置换术应用效果初步报告

目的:介绍标准型人工全关节置换术应用于颞下颌关节重建的方法,初步评价其疗效及应用价值。方法:6例(10侧)颞下颌关节病患者,年龄49～66岁,平均59岁。3例(5侧)有既往颞下颌关节手术治疗史,3例(5侧)为内紊乱伴骨关节炎。术前均有明显开口受限及关节区疼痛,开口度1.0～2.9cm,平均1.9cm。采用标准型人工关节置换术,术后定期观察开口度及关节疼痛等变化,结合影像学检查等评价治疗效果。结果:成功完成6例(10侧)人工关节置换术。术后随访7～49个月,平均17.5个月。植入关节未出现因感染、排异、松动或断裂等导致的失败。有既往手术的病例中,1例(2侧)发生假体内侧异位成骨,1例(2侧)耳颞区疼痛无法缓解,其余4例(6侧)开口受限及关节区疼痛均有较明显改善。影像学检查均未见假体松动等异常情况。结论:标准型人工全关节置换术对缓解关节疼痛有明显效果,可有效改善开口度及提高咀嚼能力,但对咀嚼肌疼痛的缓解效果不理想。     

Cryoanalgesia in the management of intractable pain in the temporomandibular joint: a five-year retrospective review

Cryoanalgesia is a controversial adjunct to the management of chronic pain, but we know of no studies that have investigated its effect in the management of temporomandibular joint (TMJ) pain. In this five-year retrospective study we treated 17 patients who had severe pain that had failed to respond to all forms of conventional conservative treatment and were not appropriate for simple open operation. None had a clear indication for open operation on the joint or had too severe disease to warrant a simple procedure. Preliminary diagnostic injections of bupivacaine to the TMJ relieved the pain. We applied the cryoprobe in the region of the auriculotemporal nerve and TMJ capsule. There was a small but insignificant improvement in mean mouth opening together with a significant (p = 0.000) improvement in visual analogue pain scores (VAS) from 6.8 (range 4–10) to 2.0 (range 0–7). Two patients had no change in their pain scores, and 2 had complete resolution of their pain. The mean number of pain-free months after treatment was 7 (IQR 3–15). Three patients had long-term pain relief, and 12 temporary relief; 6 of these subsequently had successful relief after total replacement of the TMJ. One patient had further cryoanalgesia, one was referred for specialist pain management, and one controlled the pain with nortriptyline. Of the 17 cases studied, 2 had temporary complications after cryoanalgesia. Cryoanalgesia is a useful adjunct to the management of intractable pain in the TMJ. Short-term pain relief can be achieved, and long-term relief is possible in some, deferring more complex and costly treatments.     

Outcomes of open temporomandibular joint surgery following failure to improve after arthroscopy: is there an algorithm for success?

We reviewed the results of one surgeon's experience of open surgical management of the temporomandibular joint (TMJ) in patients who fail to respond to arthroscopy and aimed to identify groups of patients that may or may not benefit from the intervention. Over a 7-year period (2005–2012) we retrospectively collected data from the medical notes of patients who underwent discectomy, disc plication, eminectomy, eminoplasty, and adhesiolysis, according to the clinical findings for joint pain, restriction, and locking. A total of 22 patients (71%) reported improvement in pain score and 19 (61%) reported an improvement in mouth opening 12 months postoperatively. Overall, 12 patients (39%) ultimately needed TMJ replacement. This group included 5/6 patients in Wilkes’ stage IV and 6/15 in stage V, 5/7 patients with a preoperative pain score of 90–100, and half of those with preoperative mouth opening of 20–29 mm (7/14). Open surgical management of the TMJ can benefit patients despite the previous failure of arthroscopy to manage pain, restriction, and locking. Arthroscopy seems to reduce the percentage of patients that need open TMJ surgery, but also the success of subsequent operations compared with previous studies. TMJ replacement is increasingly being done successfully to treat end-stage disease. These results may be used when obtaining a patient's consent for open TMJ surgery, particularly if they are in the groups considered to have a high risk of subsequently requiring a replacement joint.     

数字化导板在标准型人工颞下颌关节置换术中的应用

目的 设计并制作数字化导板（digital template）,指导标准型人工颞下颌关节置换术中的骨修整和假体定位并评价其应用效果。方法 选择2013年11月—2014年3月间收治的人工关节置换病例6例,术前将Biomet标准型人工关节假体激光扫描后导入ProPlan CMF 1.4软件,模拟假体摆放位置并据此确定骨修整范围,设计、制作多块数字化导板,分别用于术中指示骨修整范围、方向及深度,并定位假体安放位置。术后进行CT扫描,评价假体植入准确性及其与术前设计的吻合情况。结果 导板术中就位顺利,与骨面贴合,引导截骨及骨修整准确,未伤及颅底及下牙槽神经血管束等重要解剖结构。术后CT拟合结果显示,假体植入位置与术前设计的平均误差为（1.139±0.183）mm。结论 数字化导板可以准确指导标准型人工颞下颌关节置换术中的骨修整和假体定位,有利于确保假体植入的稳定性,避免了颅底及下牙槽神经血管束的损伤。     

Prospective study of the long-term outcomes and complications after total temporomandibular joint replacement: analysis at 10 years

This prospective analysis was performed to assess the long-term benefits of the TMJ Concepts joint replacement system in the UK. All patients who had replacement temporomandibular joints (TMJ) with at least 10 years of follow-up were included. The most common primary diagnoses were trauma, multiple previous operations, psoriatic arthritis, rheumatoid arthritis, degenerative disease, and ankylosis. A total of 43 patients (62 joints) were followed up for 10 years (mean age 45, range 22–70 years); 39 were female and four were male. The mean number of previous TMJ procedures was 2.5 (range 0–10). Over the 10 years of follow-up, there were significant improvements in pain score (10-point scale; decreased from 7.4 to 1.7), maximum mouth opening (increased from 21.0 mm to 34.7 mm), and dietary score (10-point scale; increased from 4.1 to 9.5). Joints in two patients failed, one secondary to a local dental infection and one due to reankylosis. None failed due to wear of the prosthesis, whether the prosthesis was standard cobalt–chrome or all-titanium. Total TMJ replacement gives good long-term improvements, both lessening pain and improving function, and is an effective form of management for irreparably damaged joints.     

Adaptability of stock TMJ prosthesis to joints that were previously treated with custom joint prosthesis

The purpose of this study was to determine if a temporomandibular joint (TMJ) replaced by a custom joint prosthesis could have been replaced by a stock joint prosthesis. Stereolithic models of patients treated with TMJ Concepts^® patient fitted joint prosthesis (e.g. custom) were obtained. Biomet Microfixation^® TMJ prostheses (e.g. stock) were adapted to these models. Intra-operative insertion of prosthesis, fit and size of stock joints were simulated and evaluated. Adaptability and stability of condyle and fossa as well as their articulation were recorded. 20 models consisting of 34 joints were examined by two oral and maxillofacial surgeons who were blinded to the patient's diagnosis. Overall, 77% of the stock TMJ system fit the stereolithic models. 3 mm or less of bone modification was necessary to achieve an acceptable fit. In the majority of the cases examined, a stock TMJ prosthesis had good anatomical adaptation to stereolithic models of patients previously treated with custom TMJ prosthesis, so a stock TMJ prosthesis could have been an acceptable option for these patients. Further prospective clinical studies to compare both systems are necessary.     

Outcomes of office-based temporomandibular joint arthroscopy: a 5-year retrospective study

Temporomandibular joint (TMJ) arthroscopy is a minimally invasive surgical approach for intra-articular TMJ diseases. Office-based arthroscopy using the smallest TMJ scope allows for good visualization, as well as the ability to lavage the joint in an office setting. This study aimed to assess the efficacy of an office-based TMJ arthroscopic technique. A retrospective evaluation of 363 patients with a TMJ disorder was performed. These patients underwent office-based arthroscopy using the OnPoint 1.2 mm Scope System (Biomet Microfixation, Jacksonville, FL, USA) in Florida, USA, from July 2007. The following outcomes of the procedure were assessed: improvement in painless range of mandibular motion, pain on loading, and functional jaw pain; these were evaluated using a visual analog scale (VAS) over an average follow-up period of 263.81 ± 142.1 days. The statistical analysis was performed using IBM SPSS Statistics version 20. Statistically significant improvements in TMJ pain and function, and other variables (P = 0.001) were shown following TMJ arthroscopic lysis and lavage. Office-based arthroscopy using the OnPoint System was demonstrated to be a safe and efficient procedure for the treatment of patients with TMJ disorders as the first level of the algorithm of care.     

Histological findings in soft tissues around temporomandibular joint prostheses after up to eight years of function

Early temporomandibular joint (TMJ) prostheses articulated on material with poor wear resistance. Wear debris was deposited in the surrounding tissues, causing severe foreign body cell reactions. Recent TMJ prostheses use modern orthopaedic materials, such as ultra high molecular weight polyethylene (UHMWPE) for the fossa component, and cobalt-chromium, or cobalt-chromium-molybdenum for the condylar head. These designs are reliable in long-term follow-up studies. The authors report histological findings in soft tissue samples obtained from around two types of TMJ prostheses after up to 8 years of function. The devices were four Biomet (Biomet Microfixation, Jacksonville, FL, USA), and two TMJ Concepts (TMJ Concepts, Ventura, CA, USA). All joint capsule samples demonstrated dense, fibrous connective tissue with no inflammatory cells or foreign body reactions. The joint disc tissues showed even denser fibrous connective tissue, free from inflammatory reactions. Some samples from the junction between capsule and disk demonstrated synovial-like tissue. The observations reported in this paper indicate that modern TMJ prostheses with Cr-Co-Mb or Cr-Co articular condyles articulating on UHMWPE fossa components appear to function without foreign body reactions in he surrounding tissues.     

One-year prospective outcome analysis and complications following total replacement of the temporomandibular joint with the TMJ Concepts system

Total replacement of the temporomandibular joint (TMJ) is increasingly accepted as the gold standard for reconstruction of irreparably damaged or ankylosed joints. The TMJ Concepts system (TMJ Concepts, Ventura, USA) has the longest follow-up of the 2 systems used in the UK. A total of 74 patients had placement of TMJ Concepts prostheses. The primary diagnoses were degenerative disease, multiple previous operations, injury, rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and ankylosis. Of these, 12 were revisions of previous replacements (3 after multiple operations). Over the year there was a significant mean (SD) reduction in pain score (10 cm visual analogue scale) from 72 (2.5) to 8 (1.7) (p < 0.0001), and mean (SD) improvements in mouth opening from 22.4 mm (9.4) to 33.7 mm (6.2) (p < 0.0001), and dietary consistency (10 cm analogue liquid 0 to solid 100) from 38 (23) to 93 (16) (p < 0.0001). No patient had worse symptoms postoperatively. Joints in 2 patients failed because of biofilm infections. Two patients required blood transfusion and one required ligation of the external carotid artery. Five had perioperative dislocation, which responded to elastic intermaxillary fixation for one week. A total of 31 patients had partial, and 2 had total weakness of the facial nerve. All resolved fully except weakness of the temporal branch in one patient, which required brow lift. Total TMJ replacement gives good early improvements in function and pain with few complications. Of the 74 patients, 71 were very pleased to have had the procedure. One was dissatisfied despite complete pain relief and improvement in mouth opening from 3 to 30 mm, and 2 were ambivalent (one had infection, revision, and permanent weakness of the temporal branch of the facial nerve).     

Total reconstruction of the temporomandibular joint. Up to 8 years of follow-up of patients treated with Biomet® total joint prostheses

12 patients underwent temporomandibular joint (TMJ) reconstruction with Biomet total joint prostheses. Indications for TMJ reconstruction included ankylosis, rheumatoid arthritis, degenerative joint disease and condylar resorption. Five patients had unilateral procedures, seven had bilateral. The follow-up ranged between 2 and 8 years. Amongst the ankylotic patients the mean jaw-opening capacity increased from 3.8 mm preoperatively to 30.2 mm 1 year after surgery, and in most of those patients the opening capacity remained stable over the years. The other patients maintained a mean opening capacity of more than 35 mm. Joint related pain and interference with eating were eliminated after TMJ reconstruction. There were no permanent facial nerve disturbance, no postoperative infections and no device related complications. The outcome supports prosthetic TMJ reconstruction as a useful treatment modality in patients with advanced TMJ disease.     

Maximum voluntary bite force in patients with alloplastic total TMJ replacement – A prospective study

Alloplastic temporomandibular total joint replacement (TJR) for end-stage disease, congenital disorders and following ablative oncological surgery has been shown to reduce pain and improve function. The purpose was to assess the maximum voluntary bite force and maximum interincisal opening (MIO) in patients undergoing alloplastic total temporomandibular joint replacement (TJR).Seventeen patients with different diagnoses resulting in condylar hypomobility (8 patients; 15 joints) and condylar instability (9 patients; 12 joints) had undergone alloplastic TMJ reconstruction. Maximum voluntary bite force and MIO were measured at pre-operatively (T0), 2 (T1), 6 (T2) and 12 (T3) months. For ordinal data comparison at different time-points, the Wilcoxon signed-ranks test was used.There was a significant improvement in maximum voluntary bite force for both, patients with condylar hypomobility (P = 0.003) and condylar instability (P = 0.007). Analysis of MIO revealed a significant improvement at T3 (P = 0.002).Alloplastic TJR would appear to increase maximum voluntary bite force and MIO. Biomechanical integrity of the stomatognathic system and the ability of the patient to triturate food could be improved by alloplastic temporomandibular joint (TMJ) replacement.     

A new three-dimensional,print-on-demand temporomandibular prosthetic total joint replacement system: Preliminary outcomes

Purpose

The aim of this study is to present the preliminary clinical data on the OMX Temporomandibular Joint (TMJ) Prosthetic total joint replacement system.

Comparative clinical outcomes between stock vs custom temporomandibular total joint replacement systems

With the evolution of temporomandibular (TMJ) prosthetic total joint replacement, there has been much debate around the advantages of custom over stock prostheses. The aim of this study is to compare the clinical outcomes of a TMJ stock prosthesis (Zimmer-Biomet) to a custom prosthesis (OMX).Clinical data from 139 prosthetic joints placed in 117 patients was retrospectively collected and analysed. All patients were diagnosed with end-stage joint osteoarthritis and were treated by a single surgeon. Minimum follow up was 2 years post-surgery.The cohort was divided into 2 groups, 60 stock prosthetic joints in 54 patients and 79 custom prosthetic joints in 63 patients. This comprised of 110 males and 7 females. The average age at the time of surgery was 53.4yr ± 12.7yr. There was no statistical difference in pre-operative MIO and pain scores between the two groups. Post-operatively, patients fitted with a custom prosthesis showed statistically significant (P = 0.013) improvement in Maximum Interincisal Opening (MIO) (+6.33 mm vs +2.53 mm) and fewer complications. Following surgery, no difference noted in pain scores and patient satisfaction between the two groups.In experienced hands, both stock and custom TMJ implants work well. However, the added advantages of custom prostheses together with growing access to digital technology is likely to result in custom devices dominating the market in TMJ total joint replacement systems.     

Reasons for failure of total temporomandibular joint replacement: a systematic review and meta-analysis

The aim of this study was to evaluate the revision rate after total alloplastic temporomandibular joint replacement (TMJR) and determine whether there is a higher risk of revision surgery with stock or custom-fitted prostheses (the two most current TMJR prosthesis types). A systematic review was performed, with a search of PubMed, Google Scholar, and the Cochrane Library in November 2020. Overall, 27 articles were included in this study, describing Biomet and TMJ Concepts prostheses and including postoperative data on complications requiring a return to the operating room. A total of 2247 prostheses were analysed: 1350 stock Biomet prostheses and 897 custom-fitted TMJ Concepts and custom-fitted Biomet prostheses. The global revision rate was 1.19 per 100 prosthesis-years. The most common reason for revision was heterotopic bone formation. Stock prostheses appeared to have a lower risk of revision compared to custom prostheses: rate ratio 0.52 (95% confidence interval 0.33–0.81, P-value 0.003). Regarding causes of revision, the only significant difference between the types of devices was a higher rate of heterotopic bone formation for custom-made prostheses (P = 0.001). The results of this study revealed a low revision rate post TMJR revision, with stock devices even less prone to such risk. Nevertheless, these results can be explained by the fact that custom-made prostheses are more likely to be used for cases in which the anatomy is significantly abnormal or there is a history of multiple joint surgeries, which carry a greater risk of complications and heterotopic bone formation.     

Technique of temporomandibular joint replacement using a patient-specific reconstruction system in the edentulous patient

The dental occlusion sets the intermaxillary relation during planning, construction of a prosthesis, and surgery for total replacement of the temporomandibular joint (TMJ), and enables accurate placement of the prosthesis. However, in edentulous patients this no longer exists. We describe techniques to overcome the problems encountered in such patients having TMJ replacement using the patient-specific TMJ Concepts^® system (Ventura, California, USA).     

Long-term outcomes after total alloplastic temporomandibular joint reconstruction following exposure to failed materials.

PURPOSE: Total alloplastic temporomandibular joint (TMJ) reconstruction is often necessary because of the significant bony destruction resulting from failed Proplast-Teflon (Vitek, Houston, TX) and/or Silastic (Dow Corning, Arlington, TX) foreign body inflammatory reactions. Multiply operated and functionless, TMJ patients likewise have undergone total alloplastic reconstruction. Many of these patients were also exposed to failed TMJ implant materials. It was the purpose of this study to evaluate a population representative of both these groups of patients reconstructed with the Techmedica (now, TMJ Concepts, Ventura, CA) Total TMJ System to determine whether the long-term subjective and objective outcomes were affected by either the presence of the previously failed TMJ implant materials, the number of prior procedures, or both. PATIENTS AND METHODS: One hundred ninety-eight patients who had been implanted with 332 Techmedica System total joints between 1990 and 1994 where divided into 4 groups based on their prior exposure to failed TMJ implant materials: group I, Proplast-Teflon (82 patients, 135 joints); group II, Silastic (28 patients, 46 joints); group III, both Proplast-Teflon and Silastic (25 patients, 46 joints); and group IV, no prior exposure to Proplast-Teflon or Silastic (63 patients, 105 joints). The mean follow-up was 60.2 +/- 40.3 months (range, 2 to 120 months). To determine whether exposure to either or both failed implant materials affected the long-term subjective and objective outcome variables, the groups were compared statistically using multivariate mixed modeling with age, sex, number of prior operations, years with TMJ problem, prior implant type, and implant sides as independent variables, and the relevant baseline measure as covariates. RESULTS: For the subjective variables, patients exposed to Proplast-Teflon or Silastic had significantly higher mean pain scores long-term. The type of prior failed TMJ implant material was not statistically significant with regard to function. Patients exposed to Proplast-Teflon reported poorer diet consistency scores long-term. Objectively, patients with 5 or fewer prior TMJ surgeries exposed to neither failed implant or Silastic reported better long-term mean maximum interincisal opening than did those patients exposed to Proplast-Teflon or both failed materials. However, for patients with 6 or more prior TMJ surgeries, those exposed to Proplast-Teflon or both failed materials reported less decrease in mean maximum interincisal opening over time. CONCLUSION: These data confirm what has been observed clinically, that in the population studied, multiply operated patients previously exposed to failed Proplast-Teflon alone or both failed Proplast-Teflon and Silastic have poorer reported long-term outcomes with alloplastic reconstruction. However, the total alloplastic TMJ reconstruction devices used in this study remained functional.