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

Total temporomandibular joint reconstruction prosthesis in hemifacial microsomia: A systematic review

Hypoplastic asymmetry due to hemifacial microsomia (HFM) often represents the most difficult reconstruction in the craniomaxillofacial clinic. Although autogenous grafts are generally used for temporomandibular joint reconstruction (TMJR), the use of TMJR prostheses is not well established. The aim of this review was to identify, collect and analyse the use of extended TMJR (eTMJR) prostheses in patients with HFM, describing clinical features, surgical procedures and postoperative complications. Online searches of all major databases were performed according to PRISMA guidelines. All studies with HFM patients treated with the eTMJR prostheses were included. Descriptive statistics were used for data analysis. A total of 19 studies, including 08 case studies, 06 case series and 05 retrospective cohort studies, met the inclusion criteria, where a total of 42 HFM patients were reported from 18 countries, mostly from the United States (05; 26%). Fifteen of the 42 cases (~36%) were male. The mean ± SD (range) age of patients in all studies was 19.79 ± 5.81 (9-36) years. The mean ± SD (range) of patient follow-up was 41.30 ± 35.50 (6-136) months. A total of 5 (10.6%) patients were implanted with bilateral eTMJR prostheses. The Pruzansky classification was used in 18 (~89.5%) studies, OMENS classification in 01 (~5%) study, whereas no classification was reported in one study. Only 01 (7.1%) study had documented the eTMJR classification for the prosthesis used. In growing patients with or without a history of failed autogenous tissues, TMJR prostheses may provide a viable alternative. Randomized studies with large cohorts are warranted to validate these preliminary results.

Extended Total Temporomandibular Joint Replacement - A Feasible Option for Functional and Aesthetic Reconstruction of Mandibular Defects Involving the Temporomandibular Joint

Study design: Retrospective case series. Objective: Alloplastic temporomandibular joint replacement has been established as a standard technique for end- stage temporomandibular (TMJ) pathologies. Joint replacement when there are extensive mandibular defects remains a challenging clinical problem. Custom-made extended temporomandibular joint replacement is a feasible option but there is limited information about this emerging technique. Methods: Included were all patients undergoing extended TMJ-replacements (TMJe), all operatrions were carried out by the senior author. Surgical technique was either single stage or two stage protocol. Surgical details and pitfalls and outcome of more than 2 years follow-up with reference to thirteen including twelve patients were recorded. Results: The most common diagnosis was ameloblastoma of the mandibular ramus. Single stage or two stagge regime were carried out depending on resection requirements and involvement of teeth. Improved mouth opening of more than 30mm was achieved in 10 of 12 patients. One patient with previous TMJ replacement reported temporary weakness of the facial nerve, which resolved after 10 months. Conclusions: The authors suggest a simplified anatomically based single-stage or two-stage regime, with both regimes achieved excellent anatomic reconstruction, facial appearance and function with low surgical morbidity. Custom-made extended temporomandibular joint protheses appear an advanced and reliable solution for reconstruction of combined complex mandibular defects including the temporomandibular joint. If surgical clearance of the pathology can be achieved, a single-stage regime is favoured.

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.

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.

Extended Complex Temporomandibular Joint Reconstructions Exploiting Virtual Surgical Planning, Navigation Assistance, and Custom-Made Prosthesis: A Comprehensive Protocol and Workflow

BACKGROUND

Alloplastic temporomandibular joint (TMJ) replacement is a well-established procedure in maxillo-facial surgery. However, the surgical management of large excision in this area requires complex reconstruction beyond the standard TMJ prosthesis.

OBJECTIVE

This study aims to describe the design and the consequential application of a protocol which involves the use of computer-assisted surgery tools to best face complex TMJ reconstruction (TMJR). Preoperative accurate study of every single case and intraoperative check of the surgical act are nowadays essential to perform such delicate surgical procedures.

MATERIALS AND METHODS

The study is a retrospective and single institution case series. The various processes of the management and planning of extended TMJ reconstruction (eTMJR) are extensively described, from the preoperative clinical evaluation, imaging acquisition protocols and virtual surgical planning (VSP), focusing also on the intraoperative transfer of VSP using navigation and surgical guides.

RESULTS

We included nine patients with different pathologies which were candidates for eTMJR. Overall, the application of our protocol and workflow permitted the reduction of complications and pain, and the improvement of the maximum interincisal opening (MIO) of the patients, restoring patients' masticatory function and esthetics.

CONCLUSIONS

The eTMJR should be considered as a safe and reliable surgical management modality in selected patients with large temporomandibular joint and skull base (TMJ-SB) lesions. An accurate preoperative protocol and workflow is essential to perform such insidious and complex reconstruction. However, more extensive studies on this type of device have to be conducted in order to validate its real usefulness and indications.

Application of Patient-Specific Implants as Alternative Approach to Zygoma Defect Management - A Retrospective Study

Introduction:

Zygoma defects are a challenging clinical problem and are frequently connected with the alteration of facial harmony, horizontal asymmetry of the face, and significant functional deficit. The application of patient-specific implants (PSIs) has the potential to improve the effectiveness of zygoma defect management. The aim of this study was to evaluate the anatomic, esthetic, and functional outcomes of PSI application for zygoma reconstruction.

Materials and Methods:

A retrospective study was conducted on data from 11 patients with zygoma defects who underwent a reconstruction procedure in which a PSI was applied and was followed for >1 year after surgery with the evaluation of esthetic and functional outcomes. Precision of PSI position and anatomy reconstruction was estimated by superimposition of the models with automatic point-to-point measurement and determination of the existing deviations between models.

Results:

The mean follow-up period in our study was 21.6 ± 6.2 months (range 14–39 months). No major complications occurred in the postoperative period: There were no clinical or computed tomography symptoms of maxillary sinusitis, implant-related infection, or implant exposure. The mean deviation between the planned and real positions of PSIs in our series was 0.72 ± 0.41 mm. The mean deviation between the reconstructed zygomatic complex and the mirrored intact side in our series was 1.45 ± 0.7 mm. The mean volume difference between the intact and damaged orbits was 1.7 ± 0.8 mm³.

Discussion:

The results of the present study support the wider clinical application of PSIs in orbital and zygoma reconstructions, as it is an effective option to achieve precise reconstruction of the complex zygoma anatomy.

Validation of an extended total joint replacement (eTJR) classification system for the temporomandibular joint (TMJ)

The aim of this paper was to validate a previously described classification system for extended total joint replacements (eTJRs) of the temporomandibular joint (TMJ). We engaged an expert panel to review 60 TMJ eTJR devices and classify them using the system, examining their responses for inter-rater agreement and concordance with the correct response as determined by the authors. Conger's kappa was 0.34 for the fossa (F) component sub-classification and 0.67 for the mandibular (M) component. A posthoc analysis showed improvements in inter-rater agreement for a modified three-tiered F sub-classification system which is suggested in a revised version of the TMJ eTJR classification system.