Alloplastic Total Temporomandibular Joint Replacement Research Articles

Hybrid total alloplastic temporomandibular joint replacement prosthesis: a pilot study to evaluate feasibility, functional performance and impact on post-operative quality of life.

The aim of the present study was to investigate the clinical efficiency of hybrid alloplastic temporomandibular joint (TMJ) prosthesis in patients undergoing TMJ total alloplastic joint replacement (TMJR). The prosthesis utilized for this study for TMJR is a hybrid variant with combination of stock prototype design and a partial customization of components. A prospective clinical study was conducted involving five patients with unilateral TMJ ankylosis or end-stage joint disease (ESJD) indicated for and requiring TMJR. The patients underwent resection of the joint or gap arthroplasty followed by TMJR using the hybrid alloplastic TMJ prosthesis. The subjective and objective variables that included the jaw function (JF), inter-incisal opening (IO), diet intake (DI) and quality of life (QoL) were assessed using the psychometric modified Likert scale. The nutritional status of the patients was evaluated using the mid-upper arm circumference (MUAC) as reference. The assessed study variables demonstrated functional and observational improvement in the post-operative follow-up when compared to the pre-operative period. The patients showed an improvement in overall QoL and nutritional status post-operatively. The follow-up period showed subjective and objective improvement in the parameters assessed among the study population. There is a technical and clinical feasibility to utilize the hybrid alloplastic TMJ prosthesis as a reliable alloplastic option for treating patients requiring TMJR, with prudent indications.

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.

Total temporomandibular mandibular joint alloplastic replacement as first line treatment for condylar fracture

The treatment of condylar fractures has been the subject of debate and controversy. Open reduction and internal fixation, along with closed reduction, are the 2 main treatment modalities when well indicated and performed. In specific situations, however, the success of both treatment modalities can be challenged by local or systemic conditions. Alloplastic total temporomandibular joint replacement (TMJR) with the current systems, Biomet and Stryker, has proven to be successful in the long-term. The authors present 2 cases and propose the consideration of TMJR as a first-line treatment for condylar fractures in the following situations: fractures older than 4 weeks; 2) elderly patients with severely dislocated or displaced condyles; 3) condylar dislocation into the cranial fossa; 4) maxillomandibular fixation is not a viable option.

Extended total temporomandibular joint reconstruction prosthesis: A comprehensive analysis

Alloplastic total temporomandibular joint replacement (TMJR) is the treatment of choice for end-stage temporomandibular joint diseases. Extended TMJR (eTMJR) is a modification of the standard alloplastic fossa-condyle joint that includes components extending further to the skull base or the mandible. The aim of this study is to review the use of the eTMJR prosthesis for the treatment of large craniomaxillofacial defects. Data mining was performed according to the PRISMA statement using online search in databases such as PubMed (Medline), Google Scholar, Dimensions, Semantic Scholar and Web of Science. A total of 19 case reports, 08 case series and 03 retrospective studies were identified. A total of 49 patients were presented in the case reports and case series, who were implanted with 56 eTMJR prostheses (07 bilateral and 42 unilateral procedures). The mean age of the patients was 36.02±16.54 years, the male to female patient ratio was 1:1.72 and the mean follow-up time was 23.74 ± 19.83 months. The eTMJR prosthesis was most frequently used to treat ameloblastoma and hemifacial microsomia. Analysis of the retrospective studies was performed in three domains: the baseline characteristic of patients, treatment outcomes in terms of functional variables and complications after eTMJR prostheses implantation. This study concluded that the implantion of the eTMJR prosthesis was uncommon, that appropriate class of eTMJR prosthesis was not reported, and that the width of the mandibular component (like the length) of eTMJR prosthesis has substantial variations.

An evaluation of clinical outcome of total alloplastic temporomandibular joint replacement and costochondral graft in temporomandibular joint ankylosis cases – A retrospective study

Background: The temporomandibular joint (TMJ) ankylosis management incorporates various modalities. Total alloplastic temporomandibular joint replacement (TJR) has opened a new avenue in TMJ reconstruction. Costochondral grafts (CCGs) are the gold standard treatment option. Aim: This study was designed to compare the clinical outcome between total alloplastic TJR and CCG in TMJ ankylosis cases. Materials and Methods: The retrospective data of patients were collected between 2017 and 2020. A total of 12 TJR cases and 8 cases of CCG were included in the study. Maximum mouth opening was recorded in mm and pain score/diet score was recorded on a Visual Analog Score system where 0 was no pain/normal diet and 10 was worse pain/liquid diet. The data were statistically analyzed using the “two-sample t-test (Welch's t-test).” Results: The mean interincisal opening in the TJR group was 32.67 (±2.19) and in the CCG group was 33.71 (±4.77). The pain reduction score was better in the TJR group with 0.5 (±0.90) and the diet score was better in the CCG group with 0.714 (±0.95). Conclusion: The stock TJR devices have a predictable outcome with a good pain reduction score and an acceptable diet score; however, the autogenous CCG is still better in terms of maximum mouth opening. Although failed CCG cases can be taken up for further correction with the TJR.

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.

Stability of the Natural Joint Side in Unilateral Alloplastic Total Temporomandibular Joint Replacement Using a Ready-Made System

An alloplastic total joint replacement (TJR) is an effective and reliable treatment option in non-salvageable end-stage temporomandibular joint (TMJ) disease. However, unilateral alloplastic TJR of the TMJ (TMJ TJR) could affect the other side natural joint because the physiologic action of both condyles is quite different during mandibular movement. In this study, we examined whether the unilaterally replaced alloplastic TMJ TJR affects the other side natural joint condition over long periods of time. Eight patients who received alloplastic TJR on one side were subjects in this study. All alloplastic TJR implants were stable in situ. The average maximum mouth opening was 37.5 mm (range 19–49 mm) pre-operatively and 44.1 mm (range 34–57 mm) post-operatively. This parameter gradually increased and reached the maximum at about twelve months after surgery. The post-operative change of pain level was significantly reduced from 3.5 to 0 on a pain scale of zero to ten. No significant complications in any joints were observed within the follow-up period. The shape of the natural joint sides showed slight changes but were functionally stable during the observation period. In this study, unilateral alloplastic TJR showed stable and reliable clinical results, either alloplastic TJR or healthy joint sides for quite long period of time.

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.

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.

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.

Evaluation of complications following stock replacement of the temporomandibular joint performed between the years 2006 and 2015: a retrospective study.

Alloplastic total temporomandibular joint replacement (TMJR) is now considered to be a standard procedure for temporomandibular joint (TMJ) reconstruction. TMJR can improve mandibular mobility, restore the dental occlusion and improve facial aesthetics. The purpose was to assess the presence of intraoperative and post-operative complications, including the presence of post-operative chronic pain. This retrospective study evaluated the use of 62 stock TMJR devices implanted in 45 patients who underwent surgery between the years 2006 and 2015 by the same surgeon at the Department of Oral and Maxillofacial Surgery, Stomatology Clinic, General Teaching Hospital (VFN) Charles University, Prague, Czech Republic. Intraoperative and post-operative complications recorded were facial nerve dysfunction (14-22%), open bite/malocclusion (2-3.2%), condylar component dislocation (1-1.6%), infection requiring revision surgery (1-1.6%) and (27-43%) reported chronic pain 24months after surgery. As with any surgical procedure, TMJR can have complications. The results of this study demonstrate that the most common post-operative complication was continued pain. Chronic pain after TMJR was more common in patients with a preoperative diagnosis of degenerative joint disease. Also, the incidence of post-operative TMJR pain increased with the duration of symptoms prior to TMJR, leading to a question of the best timing for TMJR.

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.

An Alternative Approach for Treating Severe Injured Temporomandibular Joints by Gunshot Wounds.

Temporomandibular joint (TMJ) reconstruction is a challenging clinical problem that has been revolutionized due to the development of total alloplastic TMJ replacement (TMJ-TJR); however, the costs are still very high. We used an alternative approach to treat comminuted mandibular condyle fracture with an unviable condyle head caused by gunshot wounds. Our surgical technique consisted of an extended preauricular incision; removal of the fractured condyle, bone fragments, and foreign bodies; reshape/flattening of the fracture edge; fixation of the articular disc (if viable); lining of the TMJ with temporalis muscle/fascia; application of Erich arch bars; and early elastic therapy. We successfully used this approach in five sequential cases that resulted in a good mouth opening (>35 mm) and satisfactory occlusion with teeth in maximum intercuspation. We believe that this technique is an excellent option for treating severe injured TMJs in places where TMJ-TJR is not available.

Evaluation of Total Alloplastic Temporomandibular Joint Replacement in TMJ Ankylosis.

Total joint reconstruction using autologous or alloplastic materials is one of the treatment options for the reconstruction of the affected joint in TMJ ankylosis. The clinical results of alloplastic TM joint replacement (Biomet Microfixation system) that was carried out for the treatment and reconstruction of TMJ ankylosis have been summarised. A retrospective analysis of eight cases clinically and radiographically diagnosed as TMJ ankylosis with minimal facial asymmetry presenting beyond the growth period and willing for at least 12months of follow-up who have been taken up for gap arthroplasty and reconstruction using Biomet Microfixation TMJ replacement system was carried out. Follow-up of these patients was carried out at regular intervals and assessed on the following criteria: maximal interincisal mouth opening, TM joint pain on the affected side (on VAS), lateral mandibular excursions to the unaffected side deviation on mouth opening, occlusal discrepancy and neuromotor deficit of peripheral branches of facial nerve. The mean maximal interincisal mouth opening pre-surgery and 1year post-surgery was 2 and 31.8mm, respectively. The mean lateral excursive movement to the unaffected side was found to be 5.5mm with mean deviation on mouth opening to be 4.6mm. No pain, occlusal discrepancy or neurological deficit existed at the end of 1year. Biomet Microfixation system is a viable treatment option for reconstruction of TMJ in cases of ankylosis with no major complications.

One-Stage Treatment of Giant Condylar Osteoma: Alloplastic Total Temporomandibular Joint Replacement Aided by Digital Templates

To introduce the surgical techniques and evaluate the effect of alloplastic total temporomandibular joint (TMJ) replacement aided by digital templates in giant condylar osteoma. Three patients with giant condylar osteoma were enrolled in this study. The maximal mouth opening was 1.9 cm on average. All the patients were underwent the computed tomography scan (slice thickness 1 mm) and the data were imported to Proplan 1.3 software for 3-dimensional bony segmentation and reconstruction. Osteotomy line and digital template according the 3-dimensional measurement were designed. All the joints were replaced with Biomet standard prosthesis under general anesthesia. All the operations were successfully performed. The follow-up period was from 6 to 18 months (average, 12 months). Pain relief of the joint and mouth-opening improvement were significant in 3 patients. No infection or loosening the prostheses was occurred. The occlusal relationship kept stable in all patients. Total TMJ replacement with standard prosthesis is a good strategy for TMJ reconstruction after giant condylar osteoma excision. The joint pain and the mouth-opening limitation resulted from giant condylar osteoma were markedly improved. Long-term effect remains to be evaluated based on a long-term follow-up.

Patient Perception following Alloplastic Total Temporomandibular Joint Replacement.

Introduction:A retrospective analysis was done on patients who had undergone unilateral temporomandibular joint reconstruction using alloplastic temporomandibular prostheses.Aim:The study wished to highlight patient perceptions after surgery; specifically relating to pain, function, and aesthetics.Material and Method:Twenty three patients were assessed using a visual analogue scale (VAS) for pain, ability to eat, quality of life and scar appraisal.Results:Patients Vas scores were favourable for all parameters save for scar appreciation.Conclusion:Total temporomandibular alloplastic joint replacement is a viable treatment option, with generally positive surgical outcomes for patients.

Mandibular kinematics and maximum voluntary bite force following segmental resection of the mandible without or with reconstruction

The purpose was to analyze mandibular kinematics and maximum voluntary bite force in patients following segmental resection of the mandible without and with reconstruction (autologous bone, alloplastic total temporomandibular joint replacement (TMJ TJR)). Subjects operated from April 2002 to August 2014 were enrolled in the study. Condylar (CRoM) and incisal (InRoM) range of motion and deflection during opening, condylar retrusion, incisal lateral excursion, mandibular rotation angle during opening, and maximum voluntary bite force were determined on the non-affected site and compared between groups. Influence of co-factors (defect size, soft tissue deficit, neck dissection, radiotherapy, occlusal contact zones (OCZ), and time) was determined. Twelve non-reconstructed and 26 reconstructed patients (13 autologous, 13 TMJ TJR) were included in the study. InRoM opening and bite force were significantly higher (P≤.024), and both condylar and incisal deflection during opening significantly lower (P≤.027) in reconstructed patients compared with non-reconstructed. Differences between the autologous and the TMJ TJR group were statistically not significant. Co-factors defect size, soft tissue deficit, and neck dissection had the greatest impact on kinematics and number of OCZs on bite force. Reconstructed patients (both autologous and TMJ TJR) have better overall function than non-reconstructed patients. Reconstruction of segmental mandibular resection has positive effects on mandibular function. TMJ TJR seems to be a suitable technique for the reconstruction of mandibular defects including the TMJ complex.

A custom-made temporomandibular joint prosthesis for fabrication by selective laser melting: Finite element analysis

A novel and custom-made selective laser melting (SLM) 3D-printed alloplastic temporomandibular joint (TMJ) prosthesis is proposed. The titanium-6aluminium-4vanadium (Ti-6Al-4V) condyle component and ultra-high molecular weight polyethylene (UHMWPE) fossa component comprised the total alloplastic TMJ replacement prosthesis. For the condyle component, an optimized tetrahedral open-porous scaffold with combined connection structures, i.e. an inlay rod and an onlay plate, between the prosthesis and remaining mandible was designed. The trajectory of movement of the intact condyle was assessed via kinematic analysis to facilitate the design of the fossa component. The behaviours of the intact mandible and mandible with the prosthesis were compared. The biomechanical behaviour was analysed by assessing the stress distribution on the prosthesis and strain distribution on the mandible. After muscle force was applied, the magnitude of the compressive strain on the condyle neck of the mandible with the prosthesis was lower than that on the condyle neck of the intact mandible, with the exception of the area about the screws; additionally, the magnitude of the strain at the scaffold–bone interface was relatively high.

Status of alloplastic total temporomandibular joint replacement procedures performed by members of the American Society of Temporomandibular Joint Surgeons

The purpose of this study was to assess the number of alloplastic total temporomandibular joint replacement (TMJ TJR) devices implanted and the complications encountered by members of the American Society of Temporomandibular Joint Surgeons (ASTMJS). A questionnaire was developed using REDCap (Chicago, IL) and an on-line link was e-mailed four times over a 6-week period (February to March 2015) to all members of the ASTMJS. The questionnaire included eight questions related to the surgeon's TMJ TJR experience. A Likert scale was included to assess the respondents’ opinions concerning the future demand for TMJ TJR and their thoughts on potential device improvements. The study sample was composed of 36 ASTMJS respondents (42.4%). TMJ TJR is performed successfully and in relatively high numbers by members of the American Society of Temporomandibular Joint Surgeons.