Evaluation of total alloplastic temporo-mandibular joint replacement with two different types of prostheses: A three-year prospective study

Abstract

BackgroundTemporo-Mandibular Joint (TMJ) replacement has been used clinically for years. The objective of this study was to evaluate outcomes achieved in patients with two different categories of TMJ prostheses.Material and MethodsAll patients who had a TMJ replacement (TMJR) implanted during the study period from 2006 through 2012 were included in this 3-year prospective study. All procedures were performed using the Biomet Microfixation TMJ Replacement System, and all involved replacing both the skull base component (glenoid fossa) and the mandibular condyle.ResultsFifty-seven patients (38 females and 19 males), involving 75 TMJs with severe disease requiring reconstruction (39 unilateral, 18 bilateral) were operated on consecutively, and 68 stock prostheses and 7 custom-made prostheses were implanted. The mean age at surgery was 52.6±11.5 years in the stock group and 51.8±11.7 years in the custom-made group. In the stock group, after three years of TMJR, results showed a reduction in pain intensity from 6.4±1.4 to 1.6±1.2 (p<0.001), and an improvement in jaw opening from 2.7±0.9 cm to 4.2±0.7 cm (p<0.001). In the custom-made group, after three years of TMJR, results showed a reduction in pain intensity from 6.0±1.6 to 2.2±0.4 (p<0.001), and an improvement in jaw opening from 1.5±0.5 cm to 4.3±0.6 cm (p<0.001). No statistically significant differences between two groups were detected.ConclusionsThe results of this three-year prospective study support the surgical placement of TMJ prostheses (stock prosthetic, and custom-made systems), and show that the approach is efficacious and safe, reduces pain, and improves maximum mouth opening movement, with few complications. As such, TMJR represents a viable technique and a stable long-term solution for cranio-mandibular reconstruction in patients with irreversible end-stage TMJ disease. Comparing stock and custom-made groups, no statistically significant differences were detected with respect to pain intensity reduction and maximum mouth opening improvement. Key words:Temporo-mandibular joint, temporo-mandibular joint replacement, prosthesis, biomaterials, biomedical engineering, computer-aided design and manufacturing.

Prospective study of five-year outcomes and postoperative complications after total temporomandibular joint replacement with two stock prosthetic systems

“…For such cases, we think that the use of customised prostheses is essential. 12,13,17,20,25 In conclusion, the findings of this prospective clinical study have suggested that TMJ replacement with stock pros-theses is a safe, effective, and not unduly expensive procedure for joint reconstruction in cases with irreversible end-stage TMJ disease when there is sufficient bone available to allow proper stabilisation and fixation of the implant system. Improvement of functionality as well as reduction in pain persisted for five years after completion of the joint replacement.…”

“…Similarly, the quality and quantity of bone varies considerably, meaning that fixation techniques must be suitable for different conditions. [11][12][13] In recent years, only a few systems have been available: the TMJ Concepts, the Zimmer-Biomet ® , and the Christensen System and now the Nexus CMF. Although it has been widely used, the latter has not been available since 2015 when the Food and Drug Administration withdrew its approval and, currently, there is only one stock model approved: the Biomet ® System.…”

“…Our findings correlate well with results from other studies on total joint prostheses. 13,14,[19][20][21] The strength and biocompatibility of the metal-on-ultrahigh-molecular-weight polyethylene prosthesis (BS), with its excellent wear characteristics, make it the current standard for articular surfaces of devices for total TMJ replacement. The BS implant had a lower long-term failure rate than the metalon-metal CS implant, which is not available at the present time because it is associated with several complications, including metallosis, wear of the condyle and fossa (lead-ing to fracture of the fossa), articulating wear debris-induced osteolysis, and loosening of joint replacement.…”

“…12,16,[19][20][21] Although the fit of the temporal and condylar components improves the stability of prostheses, there is no valid argument to support the fact that because a custom replacement is based on an exact adjustment to the bone it will likely offer greater durability. 13 Without doubt, one deficiency in planning a joint prosthesis is the inability to produce difficult profiles using commercially accessible stock devices. In the most complicated patients with a complex structure, it can be timeconsuming to shape the joint replacement to fit the contour of the patient's bone, and these manipulations to adapt the device to fit complex anatomical confines might make the device susceptible to fatigue fractures.…”

On the Analysis of the Contact Conditions in Temporomandibular Joint Prostheses

“…Currently, there exist 44 models depending on different sizes and dimensions for the particular configuration of the Christensen implant. On the other hand, customised TMJR devices can be represented by the ultrahigh-molecular weight polyethylene (UHMWPE) on metal (Cr-Co) Biomet Microfixation TMJ Replacement System ® [12], being the glenoid fossa cup made of UHMWPE and the mandibular condyle of Cr-Co. Figure 1 depicts the 2 mentioned TMJR types, whereas the main characteristics and differences between stock and custom-made TMJ prostheses can be found in previous research works as [17].…”