Antibiotic prophylaxis in alloplastic temporomandibular joint replacement surgery: A multi-national survey of temporomandibular joint surgeons.

Temporomandibular disorders include a wide spectrum of extra-articular and intra-articular conditions affecting the temporomandibular joint (TMJ). In salvage cases involving intra-articular end-stage disease, alloplastic temporomandibular joint replacement (TMJR) is a management option which can be utilised to rehabilitate a disabled joint's function and form. Whilst post-TMJR infection is rare, it is one of the most serious complications. The principles governing TMJR surgery antibiotic prophylaxis have been based on those established in orthopaedic surgery literature. Antibiotic resistance due to antibiotic over-use is a significant concern, therefore antibiotic stewardship has been developed to deal with this world-wide public health concern. The TMJ's anatomical proximity to the external auditory canal and oral cavity creates the potential for bacterial contamination. The aim of this study was to explore the views of 39 sub-specialist TMJ surgeons across nine nations usual approach to antibiotic prophylaxis and their management of TMJR infection. To accomplish this, an international survey was developed and conducted using Google Forms. The results demonstrated that 97.4% of the respondents employ prophylactic antibiotics at TMJR surgery, 83.8% on discharge. Variability in antibiotic choice with additional antimicrobial perioperative practices were also reported. Opinions on the management of a TMJR infection also varied. This survey establishes there is an agreement on the use of antibiotic prophylaxis, However the variability in choice, timing, course, duration of antibiotic use as well as the management of a postoperative TMJR infection demonstrates the need for further study leading to development of standardised antibiotic prophylaxis and infection management protocols for TMJR surgery.

Peri-articular bone formation involving the temporomandibular joint: a narrative summary and Delphi consensus of a new classification system.

Heterotopic ossification (HO) is defined as 'bone where it does not belong'. Given the historical variety of nomenclature and eponyms, there is significant confusion about the etiology, pathogenesis, classification, and treatment of HO related to the temporomandibular joint (TMJ). The existing classifications for TMJ HO have shortcomings: they relate to specific populations, use differing imaging studies and demographic data, do not universally include alloplastic/autologous replacements, are based variously on radiological and/or clinical presentations that cannot always be combined, and were largely developed to assist oral and maxillofacial surgeons in surgical management. These deficiencies make it problematic to compare studies, draw valid conclusions, and pursue research. The aim of this study was to develop a new, more inclusive classification for TMJ HO. Currently available classifications were evaluated and a Delphi-type system used to build consensus from clinicians and researchers to develop a new system. Fourteen unique classifications for TMJ ankylosis/HO were identified. In light of the biological specifics related to heterotopic calcification of extracellular matrix versus heterotopic formation of actual bone, the group recommends a more unambiguous term - peri-articular bone formation - and proposes a new classification. This will help clinicians and researchers to study, describe, and manage various types of ectopic bone associated with the TMJ.

Is the risk of chronic pain after total temporomandibular joint replacement independent of its indications? A prospective cohort study.

Chronic pain is a possible long-term complication after alloplastic temporomandibular joint reconstruction (TMJR). This study was developed to evaluate various subjective and objective measurements to determine the presence and degree of TMJ pain in patients treated with TMJR regardless of the indication for the operation. A prospective, single-centre study was performed. Data on 36 patients (56 TMJR) were collected preoperatively and at follow up two to three years postoperatively. The primary outcome variable was subjective TMJ pain (none/mild, moderate/severe) at follow up. The predictor variables were objective pressure pain thresholds (PPTs) at the ipsilateral joint(s) and muscle(s), functional parameters (incisal range of motion, maximum voluntary clenching), subjective oral health-related quality of life (OHRQoL), and demographic and surgical variables. The number of patients with moderate/severe pain decreased from 17 preoperatively to 10 at follow up. Self-reported TMJ pain was significantly reduced in the entire group (p = 0.001). Patients with moderate/severe pain at follow up were more restricted in their OHRQoL but did not differ in PPT and functional parameters from the no/mild pain group. Moderate/severe TMJ pain at follow up was associated with unilateral TMJR and more preoperative pain. This study provides preliminary evidence that despite good pain reduction in most patients, persistent pain after TMJR is common and, in rare cases, may even worsen regardless of the original diagnosis. At follow up there was a close relation between OHRQoL and TMJ pain. TMJ pain after TMJR cannot be confirmed by objective measurement methods (PPTs and functional parameters).

Alloplastic temporomandibular joint replacement: present status and future perspectives of the elements of embodiment.

Medical device embodiment involves the following elements: materials, design, and manufacturing. Failure of any one of these elements can result in failure of the device, despite the others being satisfactory. The abundance of clinical and basic science literature published since 1986, demonstrates the safety and efficacy of alloplastic temporomandibular joint replacement (TMJR). Currently, there are 19 countries producing 41 TMJR devices. More than 75% are custom designed, and 27% are additively manufactured. In light of the increasing number of TMJR devices being designed and manufactured around the world, this paper will discuss TMJR embodiment so that clinicians understand their present status as well as the prospects for the future of new and/or improved TMJR devices, to ensure that these devices continue to be safe and effective long-term surgical options for the management of end-stage TMJ pathologies.

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.

Impact of COVID-19 on maxillofacial surgery practice: a worldwide survey.

The outbreak of coronavirus disease 2019 (COVID-19) is rapidly changing our habits. To date, April 12, 2020, the virus has reached 209 nations, affecting 1.8 million people and causing more than 110,000 deaths. Maxillofacial surgery represents an example of a specialty that has had to adapt to this outbreak, because of the subspecialties of oncology and traumatology. The aim of this study was to examine the effect of this outbreak on the specialty of maxillofacial surgery and how the current situation is being managed on a worldwide scale. To achieve this goal, the authors developed an anonymous questionnaire which was posted on the internet and also sent to maxillofacial surgeons around the globe using membership lists from various subspecialty associations. The questionnaire asked for information about the COVID-19 situation in the respondent's country and in their workplace, and what changes they were facing in their practices in light of the outbreak. The objective was not only to collect and analyse data, but also to highlight what the specialty is facing and how it is handling the situation, in the hope that this information will be useful as a reference in the future, not only for this specialty, but also for others, should COVID-19 or a similar global threat arise again.

Alloplastic total temporomandibular joint replacement in skeletally immature patients: a pilot survey.

The aim of this study was to survey an international group of temporomandibular joint surgeons regarding their outcomes with alloplastic total joint replacement in skeletally immature patients and to review the literature linked to autogenous reconstruction and alloplastic replacement of the temporomandibular joint (TMJR) in this population. A total of 24 custom/patient-specific TMJ Concepts devices were implanted into 14 patients (eight male and six female). Their mean age was 14 years (range 7-17 years). Nine (64.3%) had bilateral devices and five (35.7%) had unilateral devices. The most prevalent diagnosis was idiopathic condylar resorption (33.3%), followed by ankylosis (16.7%). Concurrent orthognathic surgery was performed in four patients (28.6%). The TMJR was completed as a one-stage procedure in 11 patients (78.6%) and in two stages in three patients (21.4%). All surgeons reported improvements in maximum incisal opening with good function. The respondents reported no asymmetric mandibular growth or retrognathia after either bilateral or unilateral TMJR implantation. This pilot study indicates that the use of TMJR in the growing patient may be a useful modality in select cases. The encouraging results of experienced surgeons demonstrate and support the need for further studies on the utilization of TMJR in this patient population.

Review of emerging temporomandibular joint total joint replacement systems.

Total temporomandibular joint (TMJ) replacement has been documented as a viable option for the management of end-stage TMJ disease, but data on long-term outcomes have been reported for only two established systems: TMJ Concepts, and Zimmer Biomet. Other devices are now emerging globally, but reports of preclinical laboratory and clinical outcomes are limited. We retrieved information on the design, material composition, preclinical laboratory tests, regulatory status, and clinical outcomes of new TMJ replacement systems from PubMed and Google, and from personal correspondence with surgeons worldwide. Fifteen countries have developed, or are developing, 27 TMJ replacement systems, of which 21 are custom-designed, but to date, only four have been given regulatory approval. All the devices are designed to have both a skull-based glenoid fossa component and a mandibular ramus or condyle, and 22/27 are similar to the designs of the two established systems. Twenty-one devices use an ultra-high-molecular-weight polyethylene (UHMWPE) fossa-bearing surface, and 10 have a titanium alloy condyle. Nineteen manufacturers report that a titanium alloy is used for the ramus portion of the condyle/ramus component. Preclinical laboratory tests on 12 of the systems have been reported but, to our knowledge, no outcomes have yet been reported on nine of the 27 reviewed. Not all systems are equal in terms of design, material composition, preclinical laboratory testing, manufacturing methods, regulatory status, and reports of clinical outcomes.

Prevention and detection of prosthetic temporomandibular joint infections-update.

Prosthetic joint infections are not only distressing complications for patients and surgeons, but also have an enormous financial impact on healthcare systems. The reported incidence of prosthetic joint infection is likely underestimated due to difficulties in their diagnosis. This unfortunate complication has challenged joint replacement surgeons for years, despite all the advances made in this surgical discipline. Since eradication of these infections can be very difficult, prevention remains the primary objective. Identifying recipient risk factors, adopting a proper surgical technique, appropriate wound care, optimizing the operating room environment, and appropriate postoperative care have become some of the core elements that can help to minimize the overall incidence of this complication. The purpose of this article is to provide the temporomandibular joint replacement surgeon with an update on the prevention and detection of prosthetic joint infections based on a review of the most recent information published in the orthopedic and surgical literature.

Extended total temporomandibular joint replacements: a classification system.

Prosthetic total temporomandibular joint (TMJ) replacement (TJR) is well established in the United Kingdom, with clear guidelines for indications and nationally published outcomes. CAD/CAM technology has made it possible to push the boundaries of custom-made TJR to include extended versions (eTJR), which may replace segmental mandibular defects or defects in the skull base with extended components for the ramus and fossa, respectively. Such prostheses are uncommon, and published reports are restricted to isolated cases and series of cases. We know of no previous attempts to classify such prostheses, and here we suggest a bipartite classification system for use in communications between surgeons and manufacturers based on a review of 19 prostheses provided by one manufacturer (TMJ Concepts, Ventura, CA).

Biomechanical simulation of temporomandibular joint replacement (TMJR) devices: a scoping review of the finite element method.

The aim of this study was to perform a literature review on the use of finite element modeling (FEM) for the evaluation of the biomechanical behavior of temporomandibular joint replacement (TMJR) devices. An electronic search of online medical and scientific literature database was conducted using selected search terms. The search identified 307 studies, of which 19 were considered relevant to this study. Of the 19 selected studies, 10 (52.6%) investigated the influence of geometry and fixation methods, while two (10.5%) evaluated the behavior of artificial condyle-fossa structures. The TMJR devices assessed in these studies included TMJ Inc. (aka Christensen; 63.2%), Zimmer Biomet (15.7%), Stryker (10.5%), and a theoretical intramedullary condylar component (5.3%); 26.3% of the studies evaluated custom TMJR devices. Such studies provided important data on the distribution of strain and stress through TMJR structural components and surrounding bone by using different software systems and methods. The mean stress values were lower on a custom TMJR condyle-ramus component and the supporting bone than on the stock device. FEM proved to be an accurate and valuable biomechanical simulation tool for studying the current TMJR devices and should be considered a useful tool for the improvement and development of future joint replacement devices.

Acquired heterotopic ossification of the temporomandibular joint.

Although the risk factors and diagnosis of heterotopic ossification (HO) are discussed in the orthopedics literature, the etiology of HO, as well as its prevention and management, remain theoretical. Furthermore, there is a lack of information in the literature regarding HO in temporomandibular joint replacement (TMJR). This article provides a qualitative review of information relative to the etiology, diagnosis, and management of HO to inform and encourage further investigation in TMJR. The orthopedic HO literature considered for this qualitative review was drawn from a comprehensive examination of the subject published previously by one of the authors. Using the key words "heterotopic ossification" or "heterotopic bone", citations in the PubMed database from both the dental and oral and maxillofacial surgery literature were reviewed. Based on this, it appears that the etiology, diagnosis, imaging, laboratory testing, risk factors, prophylaxis, and non-surgical and surgical options available for the management of TMJR-related HO are similar to those for orthopedic HO, but further elucidation is required for TMJR. There is a lack of published information in the literature on TMJR. Therefore, using the literature from this review as a foundation, studies should be developed and reported so that alloplastic TMJ surgeons have evidence-based protocols that will lead to the early detection and potential prevention of HO.

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.

Temporomandibular joint replacement periprosthetic joint infections: a review of early diagnostic testing options.

The incidence of a periprosthetic joint infection is uncommon after total joint replacement. Since the clinical, psychological, and economic consequences of this complication are substantial, the development of management algorithms based on early diagnostic testing has been the subject of continued exploration in the orthopaedic literature. While there has been discussion of this topic in the total temporomandibular joint replacement literature and preliminary management algorithms have been established, no diagnostic testing protocols have been proposed or studied for the management of early and/or late periprosthetic joint infections. This paper will review the classification of periprosthetic joint infections, the associated risk factors, the clinical sensitivity and specificity of laboratory and imaging diagnostic studies and their utility in the management of early and late onset orthopaedic periprosthetic joint infections. This review may provide an initial framework for the use of early diagnostic testing for the management of total temporomandibular joint replacement periprosthetic joint infections and stimulate further investigation into this topic.

Alloplastic temporomandibular joint replacement: rationale for the use of custom devices.

The essential life functions of mastication, speech, airway support and deglutition are supported by temporomandibular joint (TMJ) function and form. Over a lifetime, this puts the TMJ complex under more cyclical loading and unloading than any other joint. Therefore, to provide long-term effective outcomes, the TMJ total joint replacement (TJR) device selected must be capable of managing the anatomical, functional and aesthetic discrepancies that dictated its use. The primary goal of TMJ TJR is the restoration of mandibular function and form. Outcomes data confirm that any pain relief attained must be considered of only secondary benefit. Despite persistent but reduced chronic pain, increased mandibular function and form improvement have been reported, resulting in quality of life improvement for 85% of custom TMJ TJR patients studied long-term. Based on the literature and the accepted orthopaedic criteria for the development and utilisation of successful TJR devices, this paper presents a rationale for the use of custom TMJ TJR devices as a 'fitting' management option for end-stage TMJ disorders.