Computed assisted surgery for replacement of the temporomandibular joint with customized prostheses. Can we validate the results?

Oral and Maxillofacial Surgery -     

Total reconstruction of the temporomandibular joint. Up to 8 years of follow-up of patients treated with Biomet® total joint prostheses

12 patients underwent temporomandibular joint (TMJ) reconstruction with Biomet total joint prostheses. Indications for TMJ reconstruction included ankylosis, rheumatoid arthritis, degenerative joint disease and condylar resorption. Five patients had unilateral procedures, seven had bilateral. The follow-up ranged between 2 and 8 years. Amongst the ankylotic patients the mean jaw-opening capacity increased from 3.8 mm preoperatively to 30.2 mm 1 year after surgery, and in most of those patients the opening capacity remained stable over the years. The other patients maintained a mean opening capacity of more than 35 mm. Joint related pain and interference with eating were eliminated after TMJ reconstruction. There were no permanent facial nerve disturbance, no postoperative infections and no device related complications. The outcome supports prosthetic TMJ reconstruction as a useful treatment modality in patients with advanced TMJ disease.     

Biomaterials in temporomandibular joint replacement: current status and future perspectives—a narrative review

The alloplastic total temporomandibular joint (TMJ) prosthesis has a long history, with many different materials and designs used. While several of these materials have proven valuable over time, many others have not been suitable for implantation, resulting in failure and the need for explantation of the implant. Because of the failure of several of these systems, the use of alloplastic prostheses has reduced dramatically, despite their advantages over autogenous restoration. The aim of this narrative review is to discuss the criteria that must be met by a biomaterial in order for it to be considered suitable for implantation, as well as the common complications that can occur. Currently used materials are highlighted, as well as potential future materials that might prove better suitable for implantation. Several surface modification techniques are proposed as an alternative to the materials used in current TMJ prosthesis systems.     

Juvenile porcine temporomandibular joint: Three different cartilaginous structures?

ObjectiveThe temporomandibular joint (TMJ) consists of three cartilaginous structures: the fossa, disc, and condyle. In juvenile idiopathic arthritis (JIA), inflammation of the TMJ leads to destruction of the condyle, but not of the fossa or the disc. Such a different effect of inflammation might be related to differences in matrix composition of the cartilaginous structures.MethodsThe matrix composition of the three TMJ structures was analyzed in juvenile porcine samples and in an in vitro system of cells isolated from each anatomical structure embedded in 3% agarose gels.ResultsThe matrix of all three anatomical structures of the TMJ contained collagen type I and its gene expression was maintained after isolation. The condyle and the fossa stained positive for collagen type II and proteoglycans, but the condyle contained considerably more collagen type II and proteoglycans than the fossa. The disc contained neither collagen type II protein nor expression of its gene, and the disc did not stain positive for proteoglycans. Aggrecan gene expression was lower in the disc compared to condyle and fossa cell-isolates. In general, the cell-isolates in vitro closely mimicked the characteristic features found in the tissue.ConclusionThe collagen type II content of the condyle clearly distinguished this cartilaginous structure from the disc and fossa. Since autoimmunity against collagen type II is associated with JIA, the relatively abundant presence of this type of collagen in the condyle might provide an explanation why primarily this cartilaginous structure of the TMJ is affected in JIA patients.     

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).     

Do signs of an effusion of the temporomandibular joint on magnetic resonance imaging correlate with signs and symptoms of temporomandibular joint disease?

Effusions are common among patients with disorders of the temporomandibular joint (TMJ), but publications are limited and results inconsistent about the correlation between them and important clinical variables, in particular severity of pain and degenerative disease. We organised a retrospective study of patients who presented for the evaluation and management of arthralgia of the TMJ and myofascial pain at the University of Michigan between 2011 and 2014. Inclusion criteria were: patients who had pain that was primarily arthrogenous, and coexisting myogenous pain, who had had initial non-surgical treatment, and arthroscopy of the TMJ with or without intramuscular injection of onabotulinumtoxinA (Botox,^® Allegan, Weston, Fl, USA). The primary outcome variables were pain at rest as measured by visual analogue score (VAS) and the presence of degenerative disease of the joint. The secondary outcome variables included the position of the disc and whether it was perforated, signs of synovitis, maximal interincisal opening (MIO), and duration of symptoms. We studied 47 patients (94 TMJ) who met the inclusion criteria. We found no significant differences in pain at rest before or after arthroscopy, between patients with and without effusions, or in maximal MIO or duration of symptoms between the two groups. There was, however, a significant relation between effusions and degenerative joint disease. Effusions were also associated with a lower probability of the disc being in a normal position and a higher probability of anterior disc displacement without reduction.     

Comment on “Computer-assisted surgery for replacement of the temporomandibular joint with customized prostheses: can we validate the results?”

Oral and Maxillofacial Surgery -     

Temporomandibular joint internal derangement in mandibular asymmetry. What is the relationship?

The purpose of this study was to clarify the contributing factors and their influences on temporomandibular joint internal derangement (TMJ ID) symptoms in subjects with mandibular asymmetry. Postero-anterior (PA) cephalograms of 187 pre-orthodontic treatment subjects (aged 18-45 years, mean 23.9 years) were used to investigate the inclination of the frontal occlusal (FOP) and frontal mandibular (FMP) planes to determine vertical asymmetry. Mandibular dental midline shift (DMS) and mandibular midline shift (MMS) were studied to determine transverse asymmetry. The degree of asymmetry was analysed in conjunction with the results from self-administered TMJ ID history forms. A prevalence of TMJ ID was most related to the inclination of the FMP (P < 0.01), with the symptoms being notably higher when the cant was greater than 3 degrees. The symptomatic side was related only to the inclination of the FOP and FMP. Symptoms confined to the ipsilateral side were primarily found in subjects with mild asymmetry, whereas symptoms on both sides and those on the contralateral side were greater in those with moderate and severe asymmetry, respectively. No significant correlation was found for DMS and MMS. The results suggest that the degree of asymmetry in the vertical dimension is significantly correlated with TMJ ID symptoms.     

Platelet preparations in dentistry: How? Why? Where? When?

The aim of this article is to review the outcomes of platelet preparations in dentistry. A structured electronic search discovered 348 articles, which described the use of autologous platelet concentrates with a relevance to clinical dentistry. Among these articles, 220 articles investigated platelet rich plasma, 99 investigated platelet rich fibrin, 22 investigated plasma rich in growth factors and 7 investigated the use of concentrated growth factors. Several studies reported beneficial treament outcomes in terms of enhanced bone and soft tissue regeneration.     

Can infrared thermography be a diagnostic tool for arthralgia of the temporomandibular joint?

This paper presents a review of the use of infrared thermography in diagnosis of temporomandibular joint (TMJ) arthralgia. The question examined was whether the infrared thermography could be reliably used as a tool to diagnose arthralgia by objectively assessing the site of origin and the degree of irritation. Controlled studies were performed by using advanced thermographic devices to show both diagnostic validity and reliability of infrared thermography as a screening test for selecting healthy subjects from patients with unilateral TMJ arthralgia. The study revealed that thermography fails to meet the criteria of high level of evidence. Further studies are required to confirm these results in order to specify analysis of facial thermal patterns and to better understand the relationship between TMJ arthralgia and regional temperature changes. Until then infrared thermography cannot be recommended for routine use as a diagnostic technique to identify TMJ disorders.     

How do I manage restricted mouth opening secondary to problems with the temporomandibular joint?

Restricted mouth opening is a common problem that presents to secondary care, and management depends on the primary cause. The most common differential diagnoses related to the temporomandibular joint (TMJ) include muscle spasm secondary to pain, anchored disc phenomenon, irreducible anterior disc displacement, rheumatoid diseases, and ankylosis. In this paper each is considered in turn.