Disc derangements of the temporomandibular joint

Synovial Matrix Remodeling and Inflammatory Profile in Disc Displacement of the Temporomandibular Joint: An Observational Case-Control Study

Background: Pain-related temporomandibular joint disorders (TMJD) are a major public health problem, including the diagnoses of disc displacement (DD) with and without reduction (DDwR/DDwoR). Objectives: The study aimed to examine the matrix remodeling and the inflammatory profile in synovial tissues of patients with TMJ-DD, with a view to understand the pathophysiology, and to contribute to the development of tissue-based diagnostic criteria. Methods: This laboratory-based observational case-control study included 30 synovial tissue samples obtained from 30 patients, diagnosed with delayed (DO) or sudden (SO) onset of DDwoR, which were compared against the reference patient material, DDwR (n = 10/diagnosis group). Tissue samples were investigated histologically and via quantitative immunohistochemistry for a panel of antibodies targeted against extracellular matrix proteins and inflammatory markers. The data were analyzed using a generalized linear model with a gamma family distribution (p < 0.05). Results: Quantification of immunostaining revealed significant differences in the distribution of collagen type III (DO, p < 0.001), lumican (DO, p < 0.05), matrix metalloproteinase-2 (DO, p < 0.05), CD4 T-helper cells (DO, p < 0.01; SO, p < 0.001), and CD68 monocytic immune cells (both SO and DO, p < 0.001) in DDwoR groups compared to the reference patient material, DDwR. Conclusions: The observations confirmed differences in matrix remodeling and an increase in local inflammatory activity in the DDwoR diagnosis compared to the reference patient material, DDwR. The study highlighted the importance of synovial tissue characterization to unite micropathology and clinical findings, leading to more reliable diagnostic tools.

Pre-surgical radiographic and clinical features as predictors for temporomandibular joint discectomy prognosis

OBJECTIVES

This study aimed to identify potential clinical and radiological predictors associated with the outcome of discectomies.

METHODS

In this retrospective observational study, the material comprised preoperative CBCT images and medical records of 62 patients with disc derangement disorders, who had undergone discectomy because of disc displacement with reduction (DDwR), disc displacement without reduction (DDwoR), systemic arthritis (SA), or joint hypermobility. Clinical and radiographic variables were analysed in relation to success rate determined by subjective, objective and combined outcomes.

RESULTS

The success odds ratio was 11 times higher in patients with painful DDwR versus that of SA (p = 0.03), and even 25.9 times higher when considering solely objective outcome (p = 0.03). In the absence of subchondral pseudocyst, there were 5.2 times higher odds to have a successful subjective outcome (p = 0.04). Extensive bone apposition on the temporal joint component indicated a 9.3 times higher likelihood of a failed objective outcome (p = 0.04).

CONCLUSIONS

There is a significant higher risk for combined outcome failure for the diagnosis SA involving the TMJ compared with DDwR. Predictors of importance based on CBCT findings related to the objective outcome failure were extensive bone apposition on the temporal joint component and condylar subchondral pseudocysts for the subjective outcome failure.

Synovial Tissue Proteins and Patient-Specific Variables as Predictive Factors for Temporomandibular Joint Surgery

Our knowledge of synovial tissues in patients that are scheduled for surgery as a result of temporomandibular joint (TMJ) disorders is limited. Characterising the protein profile, as well as mapping clinical preoperative variables, might increase our understanding of pathogenesis and forecast surgical outcome. A cohort of 100 patients with either disc displacement, osteoarthritis, or chronic inflammatory arthritis (CIA) was prospectively investigated for a set of preoperative clinical variables. During surgery, a synovial tissue biopsy was sampled and analysed via multi-analytic profiling. The surgical outcome was classified according to a predefined set of outcome criteria six months postoperatively. Higher concentrations of interleukin 8 (p = 0.049), matrix metalloproteinase 7 (p = 0.038), lumican (p = 0.037), and tissue inhibitor of metalloproteinase 2 (p = 0.015) were significantly related to an inferior surgical outcome. Several other proteins, which were not described earlier in the TMJ synovia, were detected but not related to surgical outcome. Bilateral masticatory muscle palpation pain had strong association to a poor outcome that was related to the diagnoses disc displacement and osteoarthritis. CIA and the patient-reported variable TMJ disability might be related to an unfavourable outcome according to the multivariate model. These findings of surgical predictors show potential in aiding clinical decision-making and they might enhance the understanding of aetiopathogenesis in TMJ disorders.

Synovial tissue cytokine profile in disc displacement of the temporomandibular joint

BACKGROUND

Symptomatic disc displacement (DD) of the temporomandibular joint (TMJ) may cause pain and limited mouth opening. The aetiopathogenesis is obscure and probably complex, which makes the diagnostic classification crude and mainly based on clinical criteria rather than disease mechanisms, and tissue characteristics.

OBJECTIVES

The study aim was to characterise and quantify synovial tissue in DD, where specific cytokine patterns might serve as potential biomarkers.

METHODS

An observational cohort study was performed harvesting synovial tissue from 63 patients: 44 with DD without reduction (DDwoR) and 19 with DD with reduction (DDwR). DDwoR was subdivided depending on type of onset (sudden, n = 17; delayed, n = 27), and DDwR served as the control group. Proteins were extracted from tissue samples and investigated in a multi-analytic profiling system.

RESULTS

DDwoR patients had significantly higher concentrations in 12 out of 28 analysed cytokines compared to DDwR. In the same statistical model, significantly lower concentrations of interferon gamma-induced protein (IP) 10, osteoprotegerin (OPG) and RANTES were detected in DDwoR patients. Women showed significantly higher concentrations of epidermal growth factor and interleukin (IL) 1ra compared to men. DDwoR with sudden onset had significant higher concentrations of bone morphogenetic protein 4, eotaxin and IL-8 compared to DDwoR with delayed onset.

CONCLUSIONS

Characterising the biomarker panel for TMJ conditions may serve as suggestible targets for disease classification and novel treatment options. The significantly lower concentrations of IP-10, OPG and RANTES could be proposed as putative markers for the separation of the studied conditions to other TMJ diseases.

Predictive factors in temporomandibular joint arthroscopy: a prospective cohort short-term outcome study

Improving the outcomes of surgical treatment of the temporomandibular joint (TMJ) is beneficial from a patient and health-economy perspective. Optimizing conditions for a successful result can be reached using validated, strict diagnostic criteria and by identifying patient-specific factors predicting the outcome. The aim of this study was to investigate possible predictive factors in TMJ arthroscopy. A prospective cohort study including 93 patients undergoing arthroscopy was conducted. The outcome was graded as successful (53%, n=49), good (25%, n=23), intermediate (20%, n=19), or deteriorated (2%, n=2) using a predefined set of objective and subjective outcome measures. The outcome was correlated with preoperative and perioperative variables and the diagnosis. Preoperative bilateral masticatory muscle tenderness on palpation was the only variable significantly correlated with a negative outcome in the adjusted regression analysis (odds ratio (OR) 2.56, P=0.048). Low age (OR 1.03, P=0.05) and bilateral joint surgery/operated side (OR 0.24, P=0.05) were found to correlate with an unsuccessful outcome in the unadjusted analysis. Eighty-nine percent of the patients with osteoarthritis benefited from arthroscopy, while corresponding figures were 80% for disc displacement without reduction and 64% for chronic inflammatory arthritis. Preoperative bilateral masticatory tenderness might be a useful predictive factor suggesting the consideration of revised non-invasive therapy before surgery.

Reduction in maximum pain after surgery in temporomandibular joint patients is associated with decreased beta-endorphin levels - a pilot study

The mechanisms of relief from persistent pain after temporomandibular joint (TMJ) surgery are not well studied. It was hypothesized that if persistent pain is relieved by TMJ surgery, up-regulated parts of the central nervous system will be desensitized and the neuroendocrine opioid release will decrease back to normal levels. Eleven female patients with a mean age of 47.4±19.4 years and with TMJ pain due to chronic closed lock were examined before and 6-24 months after TMJ discectomy. The effects on plasma β-endorphin levels, pain intensity, and pain thresholds were analyzed. Plasma β-endorphin levels (P=0.032), pain at rest (P=0.003), and movement-evoked pain (P=0.008) were all significantly reduced at follow-up. The reduction in plasma β-endorphin levels correlated with a reduction in maximum pain intensity (P=0.024) and with a longer time after surgery (P=0.041). Seven out of eight patients who reported a substantial reduction in maximum pain intensity presented a decrease in β-endorphin levels in the plasma. In conclusion, this pilot study showed a significant reduction in plasma β-endorphin levels and pain intensity at 6-24 months after TMJ surgery; plasma β-endorphin levels were correlated with time after surgery. However, the results must be interpreted with caution since this was a single-centre observational study with a small sample size. If replicated in larger sample sets, the measurement of β-endorphin levels may be of prognostic value for the treatment outcome.

Timing interventions in relation to temporomandibular joint closed lock duration: a systematic review of 'locking duration'

Temporomandibular joint (TMJ) 'closed lock' (CL) is a clinical condition causing TMJ pain and limited mouth opening (painful locking) that is mostly attributed to disc displacement without reduction (DDwoR), or less commonly to anchored disc phenomenon (ADP). Both conditions are described clinically as CL that can be 'acute' or 'chronic' depending on the duration of locking. There is, however, no consensus about the duration of locking that defines the acute state and its effect on the success of interventions. This review paper, therefore, aims to provide: (i) a narrative review of the pathophysiological need for early intervention in DDwoR and the clinical implications of acute/chronic CL stages on the management pathway; (ii) a systematic review investigating the effects of locking duration on the success of interventions for CL management. Electronic and manual searches until mid-August 2013 were conducted for English-language studies of any design investigating the effects of non-surgical and surgical interventions for acute or chronic CL (DDwoR or ADP). A total of 626 records were identified, and 113 studies were included. Data extraction and quality assessment were completed for all included studies. Included studies were, however, heterogeneous and mostly of poor-quality leading to contradictory and inconsistent evidence on the effect of the duration of locking on treatment outcomes. Future high-quality trials investigating the effect of CL duration on treatment outcome are needed. At present, early intervention by 'unlock' mandibular manipulation seems to be the most practical and realistic approach that can be attempted first in every CL patient as an initial diagnostic/therapeutic approach.

Limited fatty infiltration due to apoptosis in human degenerated temporomandibular joint disks: an immunohistochemical study

In this study, we hypothesized that caspase 3, which plays a central role in the execution phase of cell apoptosis, could be involved in limiting fatty degeneration of the temporomandibular joint (TMJ) disks and therefore inhibit the TMJ disk tissue from completely degenerating into fatty tissue. Therefore, caspase 3 immunohistochemical expression in human TMJ degenerated disks was studied. Fifty-nine degenerated TMJ disks were stained with Harry's hematoxylin, and they were then examined with light microscopy to detect any pathologic changes typical of fatty degeneration. Sections from the same TMJ disk were immunostained also by a polyclonal anti-caspase 3 antibody. On morphologic observations, 11 disks of 59 degenerated ones also presented a fatty infiltration. Immunostaining with caspase 3 antibody was detected on adipocytes in the cytoplasm as well as the nuclei. Our results sustain the hypothesis that fatty degeneration is limited by apoptosis, being adipocytes immunolabeled by caspase 3 antibody. Hence, apart from the several factors that can trigger degeneration changes in TMJ disk, their appearance, spread, and permanence, at least for fatty degeneration, seem to be influenced by apoptosis.

Reoperative temporomandibular joint surgery

TMJ surgeries are not always successful. Many potential pitfalls can occur during any phase of the treatment and can lead to complications, less than desirable results, and short- or long-term failures. Unsatisfactory results can occur for multiple reasons, including misdiagnosis of the original pathologic condition, incorrect selection of surgical technique, technical failures, complications, systemic disease, and unrealistic expectations. This article focuses on the reoperation of the TMJ primarily in cases of internal derangement and discusses TMJ arthrocentesis, arthroscopy, modified condylotomy, and open joint procedures.