Alloplastic Temporomandibular Joint Replacement Research Articles

Precise modification of surgical and positioning guides for temporomandibular joint prostheses

Alloplastic temporomandibular joint (TMJ) replacement combined with orthognathic surgery has become an increasingly frequent procedure for the maxillofacial surgeon.1–3 The use of surgical guides, which mark the osteotomies and also serve as repositioning guides for the prostheses, has become absolutely indispensable in these surgeries.4

Does Maximum Voluntary Clenching Force Pose a Risk to Overloading Alloplastic Temporomandibular Joint Replacement?—A Prospective Cohort Study

The amount of maximum voluntary clenching (MVC) force may influence functional loading at the polyethylene/metal bearing surfaces in alloplastic total temporomandibular joint replacement (TMJR). The aim of this study was to measure ipsilateral MVC and estimate the risk for revision due to overloading of the TMJR. A prospective cohort study design was used to study patients who underwent alloplastic TMJR. The primary predictor was time after TMJR, the secondary predictors were age at TMJR placement, coronoidectomy, prior ipsilateral TMJ surgeries, TMJR design (custom, stock), and bite location. The primary outcome variable was MVC, the secondary outcome was need for TMJR revision. Data were collected preoperatively (T0), and 1 year (T1), 2 to 3 years (T2) and ≥4 years postoperatively (T3). Analysis of variance (ANOVA) with post hoc Tukey-HSD and regression analysis was used for statistical analysis. P < .05 was considered significant. Thirty-seven patients (58 TMJR) with unilateral (n=16) and bilateral (n=21) TMJR were enrolled; 8 males (12 TMJR) and 29 females (46 TMJR). Average age was 46.4 ± 14.9 years. MVC increased significantly over the observation period (P = .000). At all observation time points, age at TMJR placement and bite location significantly influenced MVC (P=.000). Coronoidectomy and prior ipsilateral TMJ surgeries did not demonstrate a significant influence on MVC. TMJR design influenced MVC significantly at T3 (P=.006). Regression analysis identified age as a significant factor for higher MVC. No TMJR required revision or replacement. Based on this study, ipsilateral MVC increases significantly after TMJR. However, since MVC is significantly lower than in healthy test-patients, a considerably lower functional loading at the polyethylene/metal bearing surfaces can be assumed. Lower loading at the TMJR bearing surfaces and at the cortical screw fixation sites suggest a potential longer lifespan compared to other artificial joints like hip and knee prostheses.

Alloplastic Temporomandibular Joint Replacement in Patients With Systemic Inflammatory Arthritis and Connective Tissue Disorders

We present a retrospective study to report the outcomes of total temporomandibular joint (TMJ TJR) replacement with alloplastic devices in patients suffering from systemic inflammatory arthropathies. A total of 39 patients with a diagnosis of rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PA), juvenile idiopathic rheumatoid arthritis (JIA), or systemic lupus, underwent alloplastic total joint replacement(s) (TJR) from 1999 to 2019. Maximal interincisal opening (in mm) was recorded before surgery (T0), at 1-year post-surgery (T1) and at last follow-up (T2). A visual analog scale (from 0 to 10) was used for subjective examination of pain before surgery (T0) and at last follow-up (T2). Comparisons were conducted with statistical significance set at P < .05. Seventy-four joints were replaced in 39 patients. Thirty-two were female. The mean age was 36 years old (range 18-61) and the mean follow-up was 45.9 months (SD 49.4). The most common diagnosis was RA (n = 21), followed by JIA (n = 5) and AS (n = 5), PA (n = 4), lupus (n = 3), and mixed connective tissue disorder (n = 1). The mean pain score had fallen from 6.8 (SD 3.2) at T0 to 1.3 (SD 2.4) (P < .001) at T2. The maximal interincisal opening had improved from a mean of 22.1 mm (SD 13.3) at T0 to 34.3 mm (SD 8.5) (P < .001) at T2. One patient got persistent dysesthesia in the V3 distribution. There were no serious late complications. Patients suffering from systemic inflammatory arthropathies involving the TMJs can be successfully treated by TJR with alloplastic devices. The long-term reduction of TMJ symptoms and functional improvement in this initial study suggest good predictability for this treatment.

Total Temporomandibular Joint Prosthetic Reconstruction: The Importance of Lateral Pterygoid Muscle Reattachment to Lateral Excursive and Protrusive Mandibular Movement

AbstractSevere temporomandibular joint (TMJ) disorders result in structural changes that can significantly and negatively impact the jaw and airway, resulting in pain, difficulty chewing, dietary restrictions, sleep apnea, and other functional changes.1 For more than 5 decades, alloplastic total TMJ replacement has been used to treat end-stage intra-articular TMJ disorders. Commonly accepted measures of postsurgical success include maximal incisal opening (MIO), pain relief, and dietary and functional improvement.1Diminished or unimproved lateral and protrusive jaw movement is a commonly accepted consequence of complete TMJ replacement.2 Lateral excursive and protrusive function should, however, be considered and reported as an important measure of success after alloplastic TMJ replacement. To achieve such success, surgeons must comprehensively plan the reconstruction and reattach the lateral pterygoid muscle's inferior head (LPM-IH) to the prosthetic TMJ to support normal functional occlusion and mandibular motion.

An International Survey on Temporomandibular Joint Surgeon’s Implementation and Management of Discectomy in Treating Temporomandibular Joint Internal Derangement

To survey temporomandibular joint (TMJ) surgeons to determine current practice trends and perceptions regarding the role of discectomy for the treatment of TMJ internal derangements. An anonymous 5-part web-based survey was sent to TMJ surgeons. The survey was created and distributed, and the data were collected with the University of Michigan Qualtrics platform. Responses were compared based on operative volume, tendency to replace the disc, and likelihood of requiring temporomandibular joint replacement (TJR) after discectomy. Spearman correlations were used to test statistically significant differences. Domain-level analyses were also performed by summarizing items into 3 domain scores. Analyses were performed in SAS V9.4 (SAS Institute Inc., Cary, NC, USA). Fifty-nine surgeons (33.9%) completed the survey. Discectomy was not considered to be a useful procedure by 85% of respondents, and 74% would not consider discectomy as a first surgical option. Most would consider discectomy (64%) before alloplastic total joint replacement. Discectomy was preferred over discopexy for the management of anterior disc displacement with reduction by high volume surgeons (89%), but most (72%) did not feel that discectomy was beneficial over arthroscopy in the treatment of anterior disc displacement without reduction and concomitant degenerative bony changes. In managing symptomatic disc perforation, 66% agreed that discectomy is the procedure of choice and 49% felt that interpositional tissue is indicated in most cases after discectomy. Respondents who reported fewer re-operations requiring alloplastic TJR after discectomy had, onaverage, more positive perceptions of discectomy on the benefits domain (P=.03), better than alternatives domain (P=.03), and fewer concerns on the perceived adverse effects domain (P=.03). TMJ surgeons do not employ TMJ discectomy in most cases of TMJ internal derangement. However, discectomy is considered useful in cases of disc perforation or for persistent symptomatic disc displacement without reduction, in an attempt to avoid alloplastic TJR. Common adverse effects included joint noises and osteoarthrosis, and the use of interpositional disc replacement tissue did not alter the incidence of adverse effects or complications reported.

Evaluation of fit feasibility of TJR standard stock prosthesis in TMJ ankylosis patients of Indian population – a radiographic study

Introduction: Stock alloplastic temporomandibular joint (TMJ) replacement is challenging particularly in TMJ ankylosis patients due to the limited ramus height, undulating lateral ramus and root of zygomatic arch. Despite efforts made to standardize the sizes in available stock joint (BIOMET LORENZ), this system throw challenges in the ankylosis patients of Indian population. It limits the applicability as the system was designed based on the anatomy of American population.

Quality of life, chronic pain, insomnia, and jaw malfunction in patients after alloplastic temporomandibular joint replacement: a questionnaire-based pilot study

Studies of patients undergoing alloplastic total temporomandibular joint replacement seldom report on quality of life (QoL) and sleep. The aim of this pilot study was to assess these factors in such a patient cohort using validated psychometric questionnaires. Data were collected via online surveys comprising the following six questionnaires: Short Form-12 Health Survey (SF-12), Patient Health Questionnaire-15, European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30, Insomnia Severity Index, Graded Chronic Pain Scale, and Jaw Disability List. Pain intensity, limitation in nutrition, and treatment satisfaction were assessed using numerical rating scales. Mouth opening was measured at follow-up. The SF-12 Physical Composite Score was markedly lower than that of the age-matched general population, whereas the Mental Composite Score did not differ significantly. Participants indicated a low somatization level and low level of disability due to pain, but reduced QoL. Clinically relevant insomnia was reported by 36% of participants. In conclusion, the results of this pilot study indicate that QoL and sleep in patients with a total temporomandibular joint replacement differ from those in the general population, indicating the need for a comprehensive outcome assessment utilizing validated psychometric tools in accordance with the current biopsychosocial model of chronic disorders.

Predictors of Trigeminal Nerve Neurosensory Deficit Following Alloplastic Temporomandibular Joint Replacement

The purpose of this study was to identify factors associated with trigeminal nerve injury following alloplastic temporomandibular joint (TMJ) replacement. The sample included subjects who underwent alloplastic TMJ replacement surgery from 2010 through 2019 at the University of Texas Health Science Center at San Antonio. Operative interventions consisted of TMJ reconstruction with patient-fitted total joint replacement (TMJ TJR) either with or without orthognathic surgery. Eligible subjects included those who were evaluated for a neurosensory deficit at longest follow-up with a follow-up time of at least 6 months. The primary outcome variable was a neurosensory deficit (NSD) (i.e., trigeminal nerve sensory deficit, yes or no) defined as a score of greater than 0 on a Likert scale from 0-4 (0 = no deficit, 4 = complete deficit). Outcome variables were categorized as demographic, anatomic, and operative. Descriptive and bivariate statistics were used to identify associations between the predictor and outcome variables. P < .05 was considered statistically significant. A total of 346 joints were replaced within the defined temporal period. Of those, 176 met the necessary criteria to be included in the sample. Twenty-three subjects had unilateral TMJ TJR while 75 had bilateral replacement. Of the 98 subjects, 28 (29%) had a maxillary osteotomy in addition to the TMJ TJR. The mean age at the time of the operation was 38 + 18 years (min: 16, max: 79), and the majority of the subjects were female (n = 92, 94%). At the immediate follow-up appointment, 50 (51%) NSDs were reported, 16 of those fully recovered by the time of the longest follow-up (mean: 23 months). The maxillary division (V2) was involved in 21% (n = 7) of cases, the mandibular division (V3) in 44% (n = 15) of cases, and both divisions were involved in 35% of cases (n = 12). Specifically, the lower lip was the region most often affected. The prevalence of an NSD was significantly greater in subjects who underwent TJR with concomitant orthognathic surgery (n = 28, P = .036) compared to TJR alone (n = 70). Additionally, subjects with the diagnosis of degenerative joint disease (51%) had a statistically significant higher risk of trigeminal nerve deficits compared with all other diagnoses (P = .049). Age and gender were not statically correlated with prevalence of an NSD. Many patients undergoing alloplastic TMJ replacement who report a trigeminal nerve injury completely recover by the time of longest follow-up. A persistent NSD is associated with temporomandibular joint pathology and the extent of the operative procedure performed.

Ankylosis of the temporomandibular joint—impression free CAD/CAM based joint replacement using patient-specific implants

In recent years, alloplastic temporomandibular joint (TMJ) replacement has become a permissible procedure for the reconstruction of severely destroyed TMJs. The use of computer-aided design/computer-aided manufacturing (CAD/CAM) has extended the range of applications to complex anatomical situations. The aim of the treatment is to improve the usually restricted mouth opening and thus oral hygiene and nutrition, which leads to a regular improvement in the general quality of life. The following case report describes the bilateral replacement of ankylotically destroyed TMJs using patient-specific endoprostheses with simultaneous displacement of the maxilla. Innovative in the case described is the impression-free CAD/CAM planning, whereby the upper and lower prostheses were produced on the basis of 3D printed patient models.

How Does a Unilateral Temporomandibular Joint Replacement Affect Bilateral Masseter and Temporalis Muscle Activity?—A Prospective Study

Total alloplastic temporomandibular joint replacement (TMJR) requires the detachment of the masseter muscle (MM) at its insertion to the lateral ramus and often the resection of the coronoid process (insertion of the temporalis muscle). There is little literature on how a detachment affects the muscles. The present study evaluates the long-term masticatory muscle activities and maximum voluntary bite force (MVC) in patients with unilateral TMJR. Surface electromyography of the MM and anterior temporalis muscle during bite force testing and MVC were evaluated bilateral preoperatively (T0), 1 (T3), 2 (T4), 3 (T5), and 4years (T6) postoperatively. The percentage overlapping coefficient (index of the symmetric distribution of muscular activity) was calculated. Differences between stock or custom devices were evaluated. Fourteen patients were enrolled, 4 males and 10 females, age 47.3±14.3years at TMJR placement. In 11 patients, the coronoid process was resected, 5 patients received stock, and 9 custom prostheses. After surgery, a trend in the improvement of bilateral surface electromyography activities and MVC was found without statistical significance for the side comparison or the time of the investigation. The percentage overlapping coefficient values showed postoperatively relative (>72%) symmetry in both muscles. Up to T5 on the TMJR side, MM showed higher activity when custom prostheses were used. There was no significant difference between stock and custom prostheses. The vertical (anterior) fibers of the temporalis muscle are preserved despite the resection of the coronoid process. The anterior temporalis muscle, as a synergist of the MM on the TMJR side, postoperatively partially assumes its abduction function. The detached MM appears to reattach. Generally, the bilateral increase in muscle activity and MVC of both muscles suggests regeneration of the investigated muscles. Custom prostheses seem to have an initial advantage for the reattachment of the MM compared with stock prostheses.

The healthcare burden and associated adverse events from total alloplastic temporomandibular joint replacement: a national United States perspective

The purpose of this study was to provide a United States perspective on alloplastic total joint replacement. We sought to estimate the inpatient burden and report the most common adverse events using two administrative datasets. The National Inpatient Sample was queried from October 2015 to December 2016 for total joint replacement admissions using International Classification of Diseases 10th revision codes, and the Manufacturer and User Facility Device Experience registry was queried from January 2009 to September 2019 using manufacturer brands. The combined final sample included 114 inpatient admissions and 392 adverse events. Mean age was 43.1 years, and most patients were white (82.7%) and female (86.0%). The mean hospital charge was $108,709.43 and the mean length of stay was 2.6 days. The most common adverse events were infection (26.3%), heterotopic bone (20.9%), and poor intraoperative fit (14.0%). Fifty-four percent of cases had bilateral total joint replacements, 24.6% had simultaneous subcutaneous abdominal fat grafting, and 11.4% had simultaneous maxillary repositioning. Fat grafting and maxillary repositioning were not associated with any significant difference in the length of stay or cost. Compared to unilateral cases, bilateral total joint replacements carried significantly greater charges (P<0.01), but no increased length of stay (P=0.70), suggesting that bilateral and unilateral cases may experience a similar postoperative course.

Alloplastic temporomandibular joint replacement—what does the future hold?

: Salvage management of end-stage TMJ pathologic conditions are considered indications for alloplastic temporomandibular joint replacement (TMJR). The primary goal of TMJR is the safe and effective restoration of mandibular function and form. In order to provide successful function, form, as well as long-term subjective and objective outcomes, any present or future TMJR device must be able to safely and effectively manage the anatomic, functional, and aesthetic discrepancies presented to it for reconstruction. To accomplish this, all TMJR devices, present and future, must demonstrate that they are constructed using biologically compatible materials, designed and manufactured to bear the loads imposed on their components by function, and that they are accurately analyzed biomechanically and clinically tested to assure long-term efficacy for patients. In the future, biomechanical laboratory and clinical outcome studies should be a guide not only to surgeons and patients, but also regulatory, health care and the indemnification communities of interest. Additive manufacturing (3D printing), augmented reality (AR), artificial intelligence (AI) and robot-assisted surgery (RAS) will become important tools for the general growth and development of the specialty of oral and maxillofacial surgery. What role these will play in the future of TMJ disorder diagnosis, non-surgical and surgical management remains to be determined. This paper will discuss the past and present iterations of TMJR devices, the embodiments, the successes, and failures as a guide to what the future may hold for researchers and clinicians with regard to the development of the next generation of TMJR devices.

Accuracy of orthopantomograms in the assessment of implant position following alloplastic temporomandibular joint replacement.

The aim of this study was to determine the accuracy of orthopantomograms (OPGs) when assessing post-operative temporomandibular joint (TMJ) implant position, compared with cone beam computerized tomography (CBCT). A retrospective analysis was undertaken on six adult patients who were implanted with a custom TMJ prosthesis due to end-stage TMJ disease. Post-operative CBCT was compared with post-operative OPGs. Overall magnification of each OPG was calculated and used to linearly rescale each image. Implant position was assessed by measuring the gonion angle and the distance between each surgical screw and the mandibular gonion (SG length). Mean magnification for OPGs was 24.2%. There were no significant differences (p > 0.05) in the gonion angle on OPGs compared with CBCT images. There was a mean decrease in SG lengths of 0.02mm on OPGs, corresponding to error level of 5.31%. The 95% limits of agreement between OPGs and CBCT images for SG lengths were 1.65mm and - 1.73mm. This study presents a clinically applicable and accurate first-line radiographic screening tool to assess TMJ implant position. When combined with clinical assessment, OPGs can help reduce the need for further imaging and radiation exposure post-operatively.

Extended Total Temporomandibular Joint Replacement with Occlusal Adjustments: Pitfalls, Patient-reported Outcomes, Subclassification, and a New Paradigm.

Context:Alloplastic temporomandibular joint (TMJ) replacement is a treatment strategy for segmental mandibular defects with occlusal abnormalities.Aims:To describe our experience with extended total TMJ replacement (eTMJR) by reporting operative obstacles, complications, and patient-reported outcomes, as well as to suggest a subclassification system and paradigm shift.Setting and Design:University hospital and private clinic; case series with retrospective follow-up.Methods and Materials:Five patients (6 eTMJRs) were followed for more than 1 year after surgery. Patient-reported outcomes were assessed using FACE-Q™ “Satisfaction with Outcome” questionnaires (sum and corresponding transformed Rasch scores).Statistical Analysis:Descriptive analyses were performed.Results:Problems were related to contralateral mandibular osteotomy healing (if performed), keying the prosthetic condyle into the fossa component, intra- and postoperative prosthetic lag, and intraoperative proper establishment of the occlusion when unilateral replacement was performed. Patients reported high satisfaction with the outcome, with a mean Rasch score of 89.2/100.Conclusions:Unilateral eTMJR obstacles related to three-dimensional rotational repositioning of the remaining mandible. We suggest a paradigm shift, considering primary alloplastic replacement instead of microvascular osseous transplantation for reconstruction when radiotherapy is not required. This can avoid donor site morbidity and long reconstructive surgery. An autologous osseous transplant is still available in case of implant failure. A subclassification system is proposed for eTMJR, which accounts for contour corrections, occlusal adjustments, and simultaneous contralateral mandibular osteotomy.

In Vitro Biomechanical Simulation Testing of Custom Fabricated Temporomandibular Joint Parts Made of Electron Beam Melted Titanium, Zirconia, and Poly-Methyl Methacrylate

Total alloplastic temporomandibular joint (TMJ) replacement has become common. This in vitro study aimed to evaluate wear response of custom-fabricated electron beam melted titanium (EBM-Ti), zirconia, and acrylic TMJ parts when subjected to biomechanical simulation testing. Eighteen prosthetic TMJ parts (condyle, glenoid fossa) were custom-fabricated using computer aided design and manufacturing (CAD/CAM) techniques based on patient’s radiographic images. Biomechanical simulation testing of TMJ parts (in different combinations) were done in a modified chewing simulator (108,000 cycles, 1 Hz frequency, 45–60 N compression, strokes-downward 0.15–0.25 s/horizontal, 0.4–0.5 s/upward, 0.25–0.45 s/displacement, 1.5–2.0 mm). Qualitative analysis using scanning electron microscopy revealed wear facets on leading edges of vertical and horizontal simulation strokes. Measurement of pre-test and post-test weights of TMJ parts revealed non-significant reduction in weights due to wear. EBM-Ti and acrylic TMJ glenoid fossae articulating against zirconia condyles during simulation testing had significantly higher wear, evidenced by greater mean reduction in weights. Based on results of this preliminary study, custom-fabricated alloplastic prosthetic TMJ are a viable alternative to stock alloplastic joints. While EBM-Ti and acrylic are suitable biomaterials for custom-fabrication, use of zirconia results in greater wear and requires further studies to optimize their role in customized alloplastic TMJ.

Treatment of Progressive Condylar Resorption with Alloplastic Temporomandibular Joint Replacement

Treatment of Progressive Condylar Resorption with Alloplastic Temporomandibular Joint Replacement

Management of Anterior Open Bite secondary to TMJ disease with Custom Alloplastic TMJ Replacement

Background: Occlusal changes can occur secondary to some temporomandibular joint (TMJ) disorders. An anterior open bite (AOB) is a common finding in patients with resorptive TMJ disease. Other TMJ conditions such as trauma and paediatric ankylosis can also lead to an anterior open bite. There are several proposed treatment options including total alloplastic TMJ replacement.

Idiopathic Condylar Resorption: What Should We Do?

Idiopathic condylar resorption (ICR), alternatively called progressive condylar resorption, is an uncommon aggressive form of degenerative disease of the temporomandibular joint seen mostly in adolescent and young women. ICR occurring before the completion of growth results in a shorter mandibular condyloid process, ramus and body, compensatory growth at the gonial angle and coronoid process, as well as an increase in anterior facial vertical dimension. Management options discussed include oral appliances, orthodontics, medical management, orthognathic surgery with and without disc repositioning, and alloplastic temporomandibular joint replacement.

Are Rib Grafts Still Used for Temporomandibular Joint Reconstruction?

Patients with end-stage temporomandibular joint (TMJ) pathology require TMJ reconstruction, which can be accomplished with autogenous tissue or alloplastic materials. This survey study evaluates experienced TMJ surgeons' preferences for autogenous costochondral grafts (CCGs) and/or alloplastic prostheses for TMJ reconstruction. This cross-sectional study used an online public survey domain to query an anonymous cohort of volunteer surgeons from the American and European Societies of Temporomandibular Joint Surgeons about their TMJ reconstruction preferences. The survey questioned these surgeons' current and previous use of CCG for TMJ reconstruction, changes in practice pattern in this regard over the years, indications for CCG, and postoperative CCG outcomes. The responses were subsequently catalogued, means were calculated, descriptive statistics were analyzed, and trends were identified. Of 150 surgeons contacted, 92 responded to the survey. Of the respondents, 84 (91.3%) reported that they had performed total TMJ reconstruction in the past or continue to perform total TMJ reconstruction. However, only the 66 surgeons who completed the survey in its entirety were included in the analysis. Among these surgeons, 95.5% (63 of 66) reported that their current preferred method for TMJ reconstruction was an alloplastic TMJ replacement prosthesis; 86.4% (57 of 66) preferred a custom TMJ prosthesis, whereas 9.1% (6 of 66) preferred a stock TMJ prosthesis. Only 4.5% of the respondents (3 of 66) currently preferred CCG for TMJ reconstruction. Of the respondents, 95.5% preferred alloplastic TMJ replacement. This preference was reported based on fewer postoperative complications and more predictable outcomes using alloplastic TMJ prostheses. In cases in which CCG revision was indicated, an alloplastic TMJ prosthesis was used, indicating that surgeons should consider an alloplastic TMJ replacement device as the primary option for TMJ reconstruction for the management of most end-stage TMJ diseases.

Prevention, detection and management of prosthetic tmj infection

Background: Although uncommon, prosthetic joint infection (PJI) is one of the most distressing complications to manage for patients and surgeons following total alloplastic temporomandibular joint (TMJ) replacement. The clinical, psychological, and economic consequences of this complication can be irreversible. Since the eradication of these infections can be very difficult despite optimal care, prevention remains the primary objective.