Temporomandibular Joint Disorders and Orofacial Pain

Is there an association between rheumatoid arthritis and bone changes in the temporomandibular joint diagnosed by cone-beam computed tomography? A systematic review and meta-analysis

OBJECTIVES

Evaluate the relation of rheumatoid arthritis (RA) and bone changes in the temporomandibular joint diagnosed by cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

This systematic review and meta-analysis were recorded in the PROSPERO database, using the CRD42020153246 protocol. The electronic searches were performed in the following databases: Pubmed, Scopus, Web of Science, Lilacs, Cochrane, and Open Grey. Cross-sectional studies that evaluated patients with RA with bone changes in the temporomandibular joint diagnosed by CBCT, without language restriction or publication date, were included. Meta-analysis was performed in Stata Software (StataCorp, TX, USA, version 12.0), using the metan, and a random effects model, and the risk of different bone alterations occurring in adults with and without arthritis was estimated using odds ratios (ORs) as a pooled measure of effect. Forest plots were used to present the isolated and the pooled effects (ORs and 95% CI).

RESULTS

Six studies were used for qualitative synthesis and 2 studies for quantitative synthesis. All studies diagnosed higher prevalence changes in the bone structures of the TMJ of RA patients, described as erosion, flattening, sclerosis, and osteophytes. Meta-analysis showed that the chance of bone changes occurring in components of the TMJ is greater in individuals who have RA.

CONCLUSION

There is an association between RA and bone changes in TMJ structures diagnosed through CBCT, as RA patients were more likely to have osteoarthritic changes in this joint.

CLINICAL RELEVANCE

Understanding the existence of an association between bone alterations in TMJ and RA can assist in the management of patients.

Tuina therapy for temporomandibular joint disorder syndrome: A protocol for systematic review and meta-analysis

BACKGROUND

Temporomandibular joint disorders (TMD) is common in clinic at present, which seriously affects the mental health and quality of life of patients. With the development of society, the incidence of TMD is gradually increasing. At present, there are many treatment methods, Tuina as a characteristic traditional Chinese medicine therapy, clinical treatment of TMD has a significant effect. In recent years, there are many clinical studies on Tuina in the treatment of TMD, but the clinical efficacy of Tuina in the treatment of TMD has not been systematically evaluated. In this study, we systematically evaluated the relevant literature of Tuina in the treatment of TMD by using the method of evidence-based medicine, in order to provide reference for clinical research in this direction in the future.

METHODS

VIP Chinese database, China knowledge Network, Wanfang, China Biomedical Database, PubMed, Embase, Cochrane Library and Web of Science were searched for clinical randomized controlled trials of Tuina in the treatment of TMD from the establishment of the database to December 2020. The 2 researchers independently screened the literature and carried out quality assessment and data extraction for the included study, and used RevMan5.3 software for risk assessment and Meta analysis.

RESULTS

In this study, the efficacy and safety of Tuina in the treatment of TMD were evaluated by effective rate, visual analog score (VAS) of temporomandibular joint pain, dysfunction index ((DI), palpation index (PI), craniomandibular index (CMI), maximum mouth opening (MMO), incidence of adverse reactions and so on.

CONCLUSION

This protocol can provide evidence-based basis for the treatment of TMD, with Tuina to significantly improve the symptoms and function of patients with TMD.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/J75A8.

BRD4 inhibition alleviates mechanical stress-induced TMJ OA-like pathological changes and attenuates TREM1-mediated inflammatory response

The aim of this paper was to investigate the protective effects of bromodomain containing 4 (BRD4) inhibition on the temporomandibular joint osteoarthritis (TMJ OA) induced by compressive mechanical stress and to explore the underlying mechanism. In vivo, a rat model of TMJ compressive loading device was used and BRD4 inhibitor was injected into the TMJ region. HE staining and micro-CT analysis were used for histological and radiographic assessment. Immunohistochemistry and qPCR were performed to detect inflammatory cytokines expressions. High-throughput ChIP-sequencing screening was performed to compare the BRD4 and H3K27ac binding patterns between condylar cartilage from control and mechanical force groups. In vitro, the mandibular condylar chondrocytes were treated with IL-1β. Small Interference RNA (siRNA) infection was used to silencing BRD4 or TREM1. qPCR was performed to detect inflammatory cytokines expressions. Our study showed that BRD4 inhibition can alleviate the thinning of condylar cartilage and subchondral bone resorption, as well as decrease the inflammatory factors expression both in vivo and in vitro. ChIP-seq analysis showed that BRD4 was more enriched in the promoter region of genes related to the stress and inflammatory pathways under mechanical stress in vivo. Trem1, a pro-inflammatory gene, was screened out from the overlapped BRD4 and H3K27ac increased binding sites, and Trem1 mRNA was found to be regulated by BRD4 inhibition both in vivo and in vitro. TREM1 inhibition reduced the expression of inflammatory factors induced by IL-1β in vitro. In summary, we concluded that BRD4 inhibition can protect TMJ OA-like pathological changes induced by mechanical stress and attenuate TREM1-mediated inflammatory response.

The relation of cephalometric features to internal derangements of the temporomandibular joint: A systematic review and meta-analysis of observational studies

PURPOSE

To review and summarize the data on the relationship between craniofacial morphology features and internal derangement (ID) of the temporomandibular joint (TMJ).

METHOD

A systematic review was designed and registered at PROSPERO, CRD42019132731. The PubMed, Embase and Scopus databases were searched for cephalometric studies comparing craniofacial morphology between female patients with TMJ ID and controls. The Newcastle-Ottawa Scale (NOS) was used for quality assessment. Weighted mean differences for cephalometric measurements were pooled for subsequent meta-analysis.

RESULT

From the establishment date to August 2020, 14 of 1038 collected records were selected, which consisted of 772 patients with TMJ ID and 423 controls. These records were eventually pooled for the designed statistical analysis after the NOS quality assessment. Compared with the controls, TMJ ID patients had obviously smaller, retruded and clockwise-rotated mandible, showing significantly decreased S-Na, S-Go, Go-Me, Ar-Pog, Ar-Go, SNB, Na perp Pog, and increased FH-MP, SN-MP, PP-MP, SN to Ar-Go, S-Ar-Go and ANB.

CONCLUSION

Certain craniofacial morphology features were found strongly associated with the presence of TMJ ID, especially the size and position of the mandible.

Association between Anatomical Features of Petrotympanic Fissure and Tinnitus in Patients with Temporomandibular Joint Disorder Using CBCT Imaging: An Exploratory Study

Mandible displacement is known to correlate with otological conditions such as pain in the ear canal, hearing loss, or tinnitus. The present work aimed to determine the association between the displacement of the condyle in a temporomandibular joint, the structure and position of the petrotympanic fissure (PTF), and comorbid tinnitus in patients affected by temporomandibular joint and muscle disorder (TMD). We enrolled 331 subjects with TMD (268 women and 63 men). The average age of women was 40.8 ± 16.8 years (range 13–88), whereas the average age of the examined men was 38 ± 14 years (range 13–74). We performed imaging studies of the facial part of the skull in the sagittal plane using a volumetric imaging method and a large imaging field (FOV) of 17 cm × 23 cm. The habitual position of the mandible was determined and used as a reference. Based on the imaging results, we developed a classification for the topography and the structure of the petrotympanic fissure. Thirty-three TMD patients (about 10% of the sample) reported having tinnitus. These patients had PTF configurations characterized by a rear (36.59%) or intracranial-cranial (63.41%) condylar displacement of the temporomandibular joint. Our findings imply that the TMJ- and tinnitus-positive group of patients possibly represents a distinct phenotype of tinnitus. We concluded that for such patients, the therapeutic approach for tinnitus should include TMD treatment.

Efficacy of arthrocentesis and lavage for treatment of post-traumatic arthritis in temporomandibular joints

Objectives

Joint injuries frequently lead to progressive joint degeneration that causes articular disc derangement, joint inflammation, and osteoarthritis. Such arthropathies that arise after trauma are defined as post-traumatic arthritis (PTA). Although PTA is well recognized in knee and elbow joints, PTA in the temporomandibular joint (TMJ) has not been clearly defined. Interestingly, patients experiencing head and neck trauma without direct jaw fracture have displayed TMJ disease symptoms; however, definitive diagnosis and treatment options are not available. This study will analyze clinical aspects of PTA in TMJ and their treatment outcomes after joint arthrocentesis and lavage.

Materials and Methods

Twenty patients with history of trauma to the head and neck especially without jaw fracture were retrospectively studied. Those patients developed TMJ disease symptoms and were diagnosed by computed tomography or magnetic resonance imaging. To decrease TMJ discomfort, arthrocentesis and lavage with or without conservative therapy were applied, and efficacy was evaluated by amount of mouth opening and pain scale. Statistical differences between pre- and post-treatment values were evaluated by Wilcoxon signed-rank test.

Results

Patient age varied widely between 20 and 80 years, and causes of trauma were diverse. Duration of disease onset was measured as 508 posttrauma days, and 85% of the patients sought clinic visit within 2 years after trauma. In addition, 85% of the patients showed TMJ disc derangement without reduction, and osteoarthritis was accompanied at the traumatized side or at both sides in 40% of the patients. After arthrocentesis or lavage, maximal mouth opening was significantly increased (28-44 mm on average, P<0.001) and pain scale was dramatically decreased (7.8-3.5 of 10, P<0.001); however, concomitant conservative therapy showed no difference in treatment outcome.

Conclusion

The results of this study clarify the disease identity of PTA in TMJ and suggest early diagnosis and treatment options to manage PTA in TMJ.

Platelet Concentrate Treatments for Temporomandibular Disorders: A Systematic Review and Meta-analysis

OBJECTIVES

This systematic review compared platelet concentrates (PCs) versus hyaluronic acid (HA) or saline/Ringer's solution injections as treatments of temporomandibular osteoarthritis and disc displacement in terms of pain and maximum mouth opening (MMO).

METHODS

PubMed, Cochrane, and Scopus were searched up to March 6, 2020. Inclusion criteria were randomized clinical trials (RCTs). Exclusion criteria were case series, observational studies, animal studies, and reviews. The Effective Public Health Practice Project (EPHPP) quality assessment tool was used to assess the risk of bias in the included studies. The weighted mean difference was used to compare the results.

RESULTS

Nine RCTs were included with a total of 407 patients. The numbers of joints treated were 262, 112, and 112 in the PC, HA, and saline groups, respectively. The quality of studies was rated as strong in 4 studies, moderate in 4 studies, and weak in 1 study. The meta-analysis revealed that PCs decreased pain visual analogue scale (VAS) scores compared to HA by an average of -1.11 (CI, -1.62 to -0.60; P < 0.0001) and -0.57 (CI, -1.55 to 0.41; P = 0.26) at 3 and 12 mo follow-up respectively. Also, the average decrease in pain scores with PC compared to saline was -1.33 (CI, -2.61 to -0.06; P = 0.04), -2.07 (CI, -3.46 to -0.69; P = 0.003), and -2.71 (CI, -4.69 to -0.72; P = 0.008) at 3, 6, and 12 mo, respectively. Regarding MMO measurements, PC was comparable to HA, but it was significantly better than saline after 3 and 6 mo [2.9 mm (CI,1.47 to 4.3; P < 0.0001), and 1.69 mm (CI, 0.13 to 3.25; P = 0.03) respectively].

CONCLUSION

PC reduces pain VAS scores compared to HA during the first 3 m after treatment, and when compared to saline, it reduces pain and increases MMO for longer durations. However, due to differences between groups regarding PC preparation protocols and study heterogeneity, further standardized RCTs are required.

KNOWLEDGE TRANSFER STATEMENT

This study provides researchers and clinicians with quantitative and qualitative analyses of the current evidence regarding the clinical outcomes of platelet concentrate injections in the treatment of temporomandibular joint osteoarthritis and disc displacement in terms of pain control and maximum mouth opening.

Temporomandibular Joints' Morphology and Osteoarthritic Changes in Cone-Beam Computed Tomography Images in Patients with and without Reciprocal Clicking-A Case Control Study

Background: Patients referred for orthodontic treatment often present symptoms of temporomandibular joints’ disorders (TMD), predominantly clicking. The objective was to analyze the morphology of the temporomandibular joints in cone-beam computed tomography (CBCT) images based on the presence of reciprocal clicking before orthodontic treatment. Methods: 105 participants took part in the study. 210 temporomandibular joints (TMJs) were allocated into one of two groups regarding the presence of reciprocal clicking. Morphology of condyle’s head, glenoid fossa, and articular eminence as well as condylar head position in the glenoid fossa and osteoarthritic changes in the area of the condylar head were examined for each TMJ in the CBCT images. Statistical analysis was performed with STATISTICA version 12.0. The following tests were performed: U-Mann Whitney, Kruskal-Wallis, t-Student, and chi-square. The statistical significance level was p = 0.05 for all the measurements included. Results: Significantly smaller condylar A-P dimension (p = 0.040) characterized temporomandibular joints with reciprocal clicking. Condyles were substantially more often positioned posteriorly (p = 0.043) and were significantly more often accompanied by subcortical cysts and pathologic osteoarthritic bone changes (p < 0.001). Conclusions: The early stages of internal derangements stay with alterations in morphology and position of TMJs as well as with the presence of osteoarthritic changes.

Morphology of the Temporomandibular Joints Regarding the Presence of Osteoarthritic Changes

(1) Osteoarthritis, the most common disease of the temporomandibular joints (TMJs), is diagnosed by clinical and radiographic examination. Cone beam computed tomography (CBCT) is a method of choice for the imaging of osteoarthritic changes. The objective was to compare the morphology of the TMJs in CBCT images regarding the number of the osteoarthritic changes diagnosed in the area of the condyle. (2) A total of 105 patients participated in the study; their 210 TMJs were allocated into one of three groups regarding the number of diagnosed osteoarthritic changes: 1 (none or 1 type), 2 (2 types), 3 (3 or more types). The morphology of the TMJ was examined for each TMJ in the CBCT images. Statistical analysis was performed with STATISTICA version 12.0. The statistical significance level was p = 0.05 for all the measurements included. (3) The articular surface flattening was the most common type of the osteoarthritic changes (90%). The condylar A-P dimension differed significantly among the groups (p = 0.0001). The bigger the number of osteoarthritic changes diagnosed in one joint, the smaller the condylar A-P dimension that was observed. (4) The temporomandibular joints’ osteoarthritic changes occur very often, even among asymptomatic patients. The increased number of osteoarthritic changes seems to have an impact on the condylar anteroposterior dimension.

Facial Pain: A Comprehensive Review and Proposal for a Pragmatic Diagnostic Approach

BACKGROUND

Facial pain, alone or combined with other symptoms, is a frequent complaint. Moreover, it is a symptom situated at, more than any other pain condition, a crosspoint where several disciplines meet, for example, dentists; manual therapists; ophthalmologists; psychologists; and ear-nose-throat, pain, and internal medicine physicians besides neurologists and neurosurgeons. Recently, a new version of the most widely used classification system among neurologists for headache and facial pain, the International Classification of Headache Disorders, has been published.

OBJECTIVE

The aims of this study were to provide an overview of the most prevalent etiologies of facial pain and to provide a generic framework for the neurologist on how to manage patients presenting with facial pain.

METHODS

An overview of the different etiologies of facial pain is provided from the viewpoint of the respective clinical specialties that are confronted with facial pain. Key message: Caregivers should "think outside their own box" and refer to other disciplines when indicated. If not, a correct diagnosis can be delayed and unnecessary treatments might be given. The presented framework is aimed at excluding life- or organ-threatening diseases, providing several clinical clues and indications for technical investigations, and ultimately leading to the correct diagnosis and/or referral to other disciplines.

Painful clicking jaw: a pictorial review of internal derangement of the temporomandibular joint

Temporomandibular joint disorders are a common cause of chronic musculoskeletal pain worldwide. Among these, internal disc derangement is the most frequent type of disorder. Internal derangement is defined as an abnormal positional and functional relationship between the disc and articulating surfaces. Common clinical symptoms include pain and clicking.

Imaging plays a key role in diagnosing temporomandibular joint disorders. It is important for the radiologist to detect early imaging signs of internal derangement, thereby avoiding the evolution of this condition to degenerative joint disease. The aim of this article is to familiarise the reader with the spectrum of imaging findings that are encountered at different stages of the disease.

Muscle-Bone Crosstalk in the Masticatory System: From Biomechanical to Molecular Interactions

The masticatory system is a complex and highly organized group of structures, including craniofacial bones (maxillae and mandible), muscles, teeth, joints, and neurovascular elements. While the musculoskeletal structures of the head and neck are known to have a different embryonic origin, morphology, biomechanical demands, and biochemical characteristics than the trunk and limbs, their particular molecular basis and cell biology have been much less explored. In the last decade, the concept of muscle-bone crosstalk has emerged, comprising both the loads generated during muscle contraction and a biochemical component through soluble molecules. Bone cells embedded in the mineralized tissue respond to the biomechanical input by releasing molecular factors that impact the homeostasis of the attaching skeletal muscle. In the same way, muscle-derived factors act as soluble signals that modulate the remodeling process of the underlying bones. This concept of muscle-bone crosstalk at a molecular level is particularly interesting in the mandible, due to its tight anatomical relationship with one of the biggest and strongest masticatory muscles, the masseter. However, despite the close physical and physiological interaction of both tissues for proper functioning, this topic has been poorly addressed. Here we present one of the most detailed reviews of the literature to date regarding the biomechanical and biochemical interaction between muscles and bones of the masticatory system, both during development and in physiological or pathological remodeling processes. Evidence related to how masticatory function shapes the craniofacial bones is discussed, and a proposal presented that the masticatory muscles and craniofacial bones serve as secretory tissues. We furthermore discuss our current findings of myokines-release from masseter muscle in physiological conditions, during functional adaptation or pathology, and their putative role as bone-modulators in the craniofacial system. Finally, we address the physiological implications of the crosstalk between muscles and bones in the masticatory system, analyzing pathologies or clinical procedures in which the alteration of one of them affects the homeostasis of the other. Unveiling the mechanisms of muscle-bone crosstalk in the masticatory system opens broad possibilities for understanding and treating temporomandibular disorders, which severely impair the quality of life, with a high cost for diagnosis and management.

Management of temporomandibular joint disorders: A surgeon's perspective

Disorders of the Temporomandibular joint (TMJ) may clinically present with jaw pain and restricted mouth opening that may limit a patient's access to comprehensive dental care. The aim of this article is to provide a general overview of the current treatment strategies available in the management of disorders of the TMJ. Both conservative and surgical treatment options will be discussed as there is no one treatment for temporomandibular disorders (TMD) which encompasses a wide range of diagnoses. A multidisciplinary team approach to management is essential in the fundamental care of all TMD patients so that treatment can be specifically tailored to individual patient needs.

Regenerative Effect of Platelet Concentrates in Oral and Craniofacial Regeneration

Platelet concentrates (PCs) are biological autologous products derived from the patient's whole blood and consist mainly of supraphysiologic concentration of platelets and growth factors (GFs). These GFs have anti-inflammatory and healing enhancing properties. Overall, PCs seem to enhance bone and soft tissue healing in alveolar ridge augmentation, periodontal surgery, socket preservation, implant surgery, endodontic regeneration, sinus augmentation, bisphosphonate related osteonecrosis of the jaw (BRONJ), osteoradionecrosis, closure of oroantral communication (OAC), and oral ulcers. On the other hand, no effect was reported for gingival recession and guided tissue regeneration (GTR) procedures. Also, PCs could reduce pain and inflammatory complications in temporomandibular disorders (TMDs), oral ulcers, and extraction sockets. However, these effects have been clinically inconsistent across the literature. Differences in study designs and types of PCs used with variable concentration of platelets, GFs, and leucocytes, as well as different application forms and techniques could explain these contradictory results. This study aims to review the clinical applications of PCs in oral and craniofacial tissue regeneration and the role of their molecular components in tissue healing.

Alternative cone-beam CT method for the analysis of mandibular condylar bone in patients with degenerative joint disease

OBJECTIVE

The aim of this study was to investigate the use of 3D microstructural bone analysis in patients with degenerative joint disorder (DJD) to enhance the diagnostic capacity of cone beam computed tomography (CBCT) in the evaluation of bone tissue.

METHODS

147 TMJ CBCT images of 88 participants were assessed with regard to DJD in the mandibular condyle. We divided each condyle into 3 groups (0, 1, 2) according to diagnosis of DJD: 0 indicates normal condyles (control individuals), 1 indicates mild erosive osteoarthritic change (EOC) and 2 indicates severe EOC. 3D fractal dimension (FD) was calculated on CBCT images of mandibular condyle and were compared with the radiographic diagnosis of patients.

RESULTS

ANOVA test showed that there was statistically significant difference in FD values among each groups. The average FD value of group 0 was 1.971, group 1 was 1.918 and group 2 was 1.863. Lower FD values and more severe degenerative changes were seen in patient group 2. To evaluate the reliability of fractal analysis (FA) method, receiver operating characteristic (ROC) curve analysis was performed. Area under the curve (AUC) was 0.717 (p < 0.001).

CONCLUSION

This study provides a preliminary conclusion that fractal analysis may be a helpful tool to enhance the diagnostic capacity of CBCT in the evaluation of DJD.

Therapeutic effect of low-intensity pulsed ultrasound on temporomandibular joint injury induced by chronic sleep deprivation in rats

Low-intensity pulsed ultrasound (LIPUS) treatment is an emerging physical therapy for treating bone, nerve, and muscle disorders. However, there have been no reports on the effectiveness of LIPUS for the treatment of temporomandibular joint injury, and the mechanisms of LIPUS remain unclear. The purpose of this study was to examine the therapeutic effects of LIPUS on temporomandibular joint injury in rats subjected to chronic sleep deprivation (CSD). In this study, after 2 weeks of chronic sleep deprivation in rats, the condylar cartilage exhibited rough surfaces, with a disorganized arrangement and partial sloughing of collagen fibers, decreased proliferation of chondrocytes, increased osteoclast activity in the calcified cartilage layer, and increased ratios of MMP-3/TIMP-1 and RANKL/OPG expression. After 4 weeks of LIPUS intervention in rats, the condylar cartilage displayed prominent reductions in these pathological changes, including noticeable repair of the injured cartilage structure, increased chondrocyte proliferation, a reduced number of osteoclasts, and marked reductions in the expression ratios of MMP-3/TIMP-1 and RANKL/OPG. These results demonstrated that LIPUS can effectively inhibit CSD-induced injury to condylar cartilage in rats. The therapeutic mechanism of LIPUS may involve promoting the repair function of chondrocytes and reducing the expression ratios of MMP-3/TIMP-1 and RANKL/OPG in condylar tissue, thus inhibiting the cleavage activity of MMP-3 on the condylar cartilage matrix and inhibiting osteoclast activation.

Temporomandibular joint morphology does not influence the presence of arthralgia in patients with disk displacement with reduction: a magnetic resonance imaging-based study

OBJECTIVE

The aim of this study was to compare, by using magnetic resonance imaging (MRI), temporomandibular joint (TMJ) morphology between patients with disk displacement with reduction (DDWR) with or without arthralgia and a control group and to identify which factors are associated with the concomitant presence of arthralgia in DDWR patients.

STUDY DESIGN

In this investigation, 36 TMJ MRIs were divided into 3 groups. Group 1 (n = 12) comprised patients with DDWR and arthralgia; group 2 (n = 12) comprised patients with DDWR without arthralgia; and group 3 (n = 12) was the control group. Disk and mandibular condyle morphologies; articular eminence morphology and inclination; size of the mandibular fossa; joint space size; joint effusion; bone marrow of the mandibular condyle; and the relative signal intensity of retrodiscal tissue were evaluated.

RESULTS

Fisher's exact test and 1-way analysis of variance (ANOVA) revealed no significant differences (P > .05) between groups for any variable. Logistic regression analysis showed that no anatomic variables were related to the concomitant presence of arthralgia in patients with DDWR (P > .05).

CONCLUSIONS

As evaluated on MRI scans, no significant differences in the anatomic characteristics of the TMJ were detected between DDWR patients with or without concomitant arthralgia and the control group. There were no factors associated with the concomitant presence of arthralgia in patients with DDWR.

Changes in temporomandibular joint anatomy, changes in condylar translation, and their relationship with disc displacement: magnetic resonance imaging study

Objective

To assess changes in the articular surfaces of the temporomandibular joint (TMJ) and in condylar translation, as detected by magnetic resonance imaging (MRI), determining whether such changes correlate with disc displacement.

Materials and Methods

We retrospectively analyzed the MRI scans of 2076 TMJs of 1038 patients with symptoms of temporomandibular disorder. We attempted to determine whether articular disc deformity and changes in condylar translation, as well as changes in the articular surfaces of the condyle, glenoid fossa, and articular eminence, correlated with disc displacement.

Results

Disc displacement with reduction was associated with changes in the shape of the articular eminence. Disc displacement without reduction was most strongly associated with disc deformity, condylar degeneration, glenoid fossa degeneration, and effusion. Neither decreases nor increases in condylar translation were associated with disc deformity, degenerative bone changes, or disc displacement.

Conclusion

Changes in the shape of the articular eminence seem to predispose to progression of internal derangement of the TMJ.

Mandibular Bone Loss after Masticatory Muscles Intervention with Botulinum Toxin: An Approach from Basic Research to Clinical Findings

The injection of botulinum toxin type A (BoNT/A) in the masticatory muscles, to cause its temporary paralysis, is a widely used intervention for clinical disorders such as oromandibular dystonia, sleep bruxism, and aesthetics (i.e., masseteric hypertrophy). Considering that muscle contraction is required for mechano-transduction to maintain bone homeostasis, it is relevant to address the bone adverse effects associated with muscle condition after this intervention. Our aim is to condense the current and relevant literature about mandibular bone loss in fully mature mammals after BoNT/A intervention in the masticatory muscles. Here, we compile evidence from animal models (mice, rats, and rabbits) to clinical studies, demonstrating that BoNT/A-induced masticatory muscle atrophy promotes mandibular bone loss. Mandibular bone-related adverse effects involve cellular and metabolic changes, microstructure degradation, and morphological alterations. While bone loss has been detected at the mandibular condyle or alveolar bone, cellular and molecular mechanisms involved in this process must still be elucidated. Further basic research could provide evidence for designing strategies to control the undesired effects on bone during the therapeutic use of BoNT/A. However, in the meantime, we consider it essential that patients treated with BoNT/A in the masticatory muscles be warned about a putative collateral mandibular bone damage.

CBCT characteristics and interpretation challenges of temporomandibular joint osteoarthritis in a hand osteoarthritis cohort

OBJECTIVES

To characterise osteoarthritis (OA) in the temporomandibular joints (TMJs) by means of cone beam CT in a hand OA population, and identify interpretation challenges.

METHODS

The TMJs of 54 individuals (mean age 71.3) recruited from the "The Oslo hand OA cohort", independently of TMJ-related symptoms, were examined with cone beam CT (ProMax MidCBCT). Images were analysed for bone change characteristics and each joint was diagnosed with either OA, no OA or as indeterminate for OA. The image analysis criteria developed for the Research Diagnostic Criteria for Temporomandibular Disorders were used. Frequencies of bone changes, joint diagnoses and severity grades (1-2) were calculated, as well as κ values for observer agreement.

RESULTS

In the OA joints, the most frequent bone changes occurred in the condyle: flattening (79%), osteophyte (72%) and subcortical sclerosis (70%). The most frequent changes in the fossa/eminence were flattening (57%), erosion (49%) and subcortical sclerosis (47%). 53 (49%) of the 108 joints were diagnosed with TMJ OA (68 % Grade 2), 29 joints (27%) with no OA, and 26 joints (24%) were indeterminate for OA. Inter- and intraobserver agreement showed mean κ values of 0.67 and 0.62, respectively.

CONCLUSIONS

TMJ changes were common in elderly with hand OA and characterised by bone productive changes. The radiologic features indicated a late stage TMJ OA. Interpretation challenges related to subtle changes were identified and are reflected by the rather low observer agreement. The diagnosis of TMJ OA should be based on evident and clear abnormalities only.

Prevalence of temporomandibular joint disorder in people with Parkinson’s disease in a public university hospital

ABSTRACT Objective: to evaluate the prevalence of temporomandibular joint disorder in people with Parkinson’s disease in a public university hospital, and relate it to sociodemographic factors, general health and oral health self-report, and phase and time of illness. Methods: the Research Diagnostic Criteria for Temporomandibular Disorders were used. The sample was classified according to the diagnosis of temporomandibular disorder and associated with the variables. The odds ratio of Chi-square was applied with a 95% confidence interval and a level of significance set at p<0.05. Results: 110 people presented with Parkinson's disease were assessed. The prevalence of temporomandibular disorder was 35%, being more frequent among males (58%), in elderly people (53%), in phase 2 of the disease (61%), click (37%) being the predominant clinical indication. Of the variables analyzed, only gender and self-perception of oral health showed to be associated with temporomandibular disorders. Conclusion: the presence of temporomandibular disorder has been observed in people with Parkinson's disease, and the fact of being male and reporting moderate oral health seen as associated factors.

Osteoarthritis of the temporomandibular joint and increase of the horizontal condylar angle: a longitudinal study

OBJECTIVE

Our previous study of patients with unilateral temporomandibular joint (TMJ) osteoarthritis (OA) showed that the affected joints had greater horizontal condylar angle (HCA) compared with the contralateral unaffected joints. However, it was unclear whether the HCA changes preceded or were the result of OA changes. The aim of this longitudinal study was to investigate the relationship between HCA and OA progression.

STUDY DESIGN

In total, 127 patients (with or without TMJ disorders) completed baseline and follow-up examinations (average time to follow-up 7.9 years). Generalized estimating equation models were used to account for correlation of observations within the same patients.

RESULTS

(1) HCA was greater in OA-affected joints than in unaffected joints (P = .04). (2) Increased HCA at follow-up was associated with change in joint status from no OA to OA. (P = .001). (3) Baseline HCA value alone did not predict future OA diagnosis. (4) All OA changes in fossa/articular eminence morphology, and some combinations of condylar changes, were associated with a greater HCA. (5) OA diagnosis was associated with pain during maximum opening (P = .005) and pain history (P = .002). (6) Aging alone was not correlated with increased HCA.

CONCLUSIONS

Clinical progression of OA preceded increases in HCA. HCA alone did not predict OA development.

Effect of Shortened Dental Arch on Temporomandibular Joint Intra-articular Disorders

AIMS

To investigate whether a shortened dental arch (SDA), as identified by reduced posterior occlusal contacts, is a risk factor for the progression of temporomandibular joint (TMJ) intra-articular disorders (ID), as identified using imaging techniques.

METHODS

This multisite, prospective observational study with a mean follow-up period of 7.9 years had a sample of 345 participants with at least 1 temporomandibular disorder (TMD) diagnosis at baseline. SDA was defined as reduced occlusal posterior support due to lack of occlusal intercuspal contacts in the molar region on the left and/or right side. SDA was assessed at baseline and at follow-up with metalized Mylar Tape. The presence or absence of a TMJ ID and the specific TMJ ID diagnoses for baseline and follow-up images were established by a calibrated, blinded radiologist at each of three sites by using bilateral magnetic resonance imaging for soft tissue imaging for disc displacement and by bilateral multidetector computed tomography or cone beam computed tomography for hard tissue imaging for degenerative joint diseases. Wilcoxon rank sum test and linear regression analyses were used to test for an impact of SDA on TMJ ID status.

RESULTS

At baseline, TMJ ID status of either side was not significantly affected by the presence of SDA on the ipsilateral or contralateral side of the jaw (all P > .05). Furthermore, the presence or absence of SDA at baseline was also not a significant predictor for progression of the TMJ ID status between baseline and follow-up (all P > .05).

CONCLUSION

The findings of this study suggest that there is no significant effect of SDA on progression of TMJ ID.

Imaging in Orofacial Pain

Imaging usefulness in the diagnosis of orofacial pain includes all modalities that cover the soft tissue and bony structures in the region of the head and neck. Imaging techniques may include 2-dimensional and/or 3-dimensional imaging modalities. Both dentists and physicians should be aware of orofacial pain associated with a variety of sources and select the appropriate imaging technique based on the patient's medical and dental history and the clinical examination. The goal of imaging is to provide the clinician with information that will confirm or deny findings of the clinical examination and allow for the selection of an appropriate treatment.

Mechanobehavior and Ontogenesis of the Temporomandibular Joint

Craniofacial secondary cartilages of the mandibular condyle and temporomandibular joint (TMJ) eminence grow in response to the local mechanical environment. The intervening TMJ disc distributes normal loads over the cartilage surfaces and provides lubrication. A better understanding of the mechanical environment and its effects on growth, development, and degeneration of the TMJ may improve treatments aimed at modifying jaw growth and preventing or reversing degenerative joint disease (DJD). This review highlights data recorded in human subjects and from computer modeling that elucidate the role of mechanics in TMJ ontogeny. Presented data provide an approximation of the age-related changes in jaw-loading behaviors and TMJ contact mechanics. The cells of the mandibular condyle, eminence, and disc respond to the mechanical environment associated with behaviors and ultimately determine the TMJ components' mature morphologies and susceptibility to precocious development of DJD compared to postcranial joints. The TMJ disc may be especially prone to degenerative change due to its avascularity and steep oxygen and glucose gradients consequent to high cell density and rate of nutrient consumption, as well as low solute diffusivities. The combined effects of strain-related hypoxia and limited glucose concentrations dramatically affect synthesis of the extracellular matrix (ECM), which limit repair capabilities. Magnitude and frequency of jaw loading influence this localized in situ environment, including stem and fibrocartilage cell chemistry, as well as the rate of ECM mechanical fatigue. Key in vivo measurements to characterize the mechanical environment include the concentration of work input to articulating tissues, known as energy density, and the percentage of time that muscles are used to load the jaws out of a total recording time, known as duty factor. Combining these measurements into a mechanobehavioral score and linking these to results of computer models of strain-regulated biochemical events may elucidate the mechanisms responsible for growth, maintenance, and deterioration of TMJ tissues.

The Efficiency of Anterior Repositioning Splints in the Management of Pain Related to Temporomandibular Joint Disc Displacement with Reduction

Background and Objective

Intra-articular temporomandibular disorders are often related to pain in the area of the temporomandibular joint, ear, and temple. The aim of the study was to investigate the efficiency of anterior repositioning splints in decreasing pain related to temporomandibular joint disc displacement with reduction.

Methods

The research material consisted of 112 patients, aged 24 to 45 years, of both genders, who reported for treatment at the Consulting Room of Temporomandibular Joint Dysfunctions at the Jagiellonian University in Cracow between 2014 and 2016 due to pain in the area of the temporomandibular joint(s) and noise(s) of temporomandibular joint(s) present during jaw movements with comorbid contracture of masticatory muscles. Subjects were examined according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) protocol and, after diagnosis of painful disc displacement with reduction and masticatory muscle contracture, they were assigned randomly to either the study or control groups (56 patients in each). In the study group, we used an anterior repositioning splint on the full lower arch for about 20 hours usage over a 4-month period. In the control group, a noninvasive therapy was applied using a biostimulation laser over 12 sessions performed every second day on the area of both temporomandibular joints with mouth open and while performing muscle self-exercises with a dominant protrusive position of the mandible. Pain intensity was evaluated using the Verbal Numerical Rating Scale (VNRS) immediately before the treatment and then after 4 and 16 weeks. The obtained data were analyzed using the Mann–Whitney U test (p ≤ 0.005).

Results

The VNRS values reported during the final examination for the study group were significantly lower than for the control group (p=0.0004).

Conclusions

The anterior repositioning splint is an efficient tool in decreasing pain related to disc displacement with reduction. This trial is registered with Clinicaltrials.gov NCT03057262.

A Young Patient with Temporomandibular Joint Osteoarthritis: Case Report

This paper describes a case of a young patient who sought help because of pain in the right temporomandibular joint (TMJ). She also reported increasing of pain during chewing. Clinical examination revealed limited mouth opening with uncorrected deviation to the ipsilateral side. Palpation of the lateral pole of the right condyle discovered crepitus, and maximum assisted opening elicited a report of "familiar pain". The diagnosis of osteoarthritis of the TMJ (RDC / TMD criteria, Axis I, Group III) was confirmed by CBCT of TMJ. There is no "gold standard" for the management of TMD, but the need for TMD treatment has to be based on precise indications related to the presence of pain, limitation in function of the lower jaw and signs of degenerative joint disease. Conservative, reversible therapeutic procedures are considered as the first choice for TMD treatment and their task is to improve the function of the entire masticatory system. In this case patient was treated with the combination of physical therapy and stabilization splint, in order to reduce the pain and restore the normal function of the lower jaw. At 6 months’ follow-up symptoms have almost completely disappeared, while 3 years later, the patient still has no significant subjective symptoms. In the present case non-invasive therapy was sufficient to bring, otherwise recurrent nature of osteoarthritis, in complete remission and keep it like that for years.

Microneedles enhance topical delivery of 15-deoxy-Δ12,14-prostaglandin J2 and reduce nociception in temporomandibular joint of rats

The pain arising from temporomandibular disorders is often treated with opioids and agents that inhibit the immune response and are associated with substantial adverse effects and long-term risks. Thus, the development of new therapies that are safer and more effective is of great interest to patients and clinicians. 15-deoxy-Δ^12,14-prostaglandin J₂ (15d-PGJ₂) is naturally produced in the human body and has anti-inflammatory properties. We have previously shown in a rat temporomandibular joint (TMJ) model that injection of 15d-PGJ₂ into the rat TMJ can provide antinociceptive relief against a subsequent noxious challenge from formalin injection into the same TMJ. However, intra-TMJ injections are painful. Thus, to make the treatment patient friendly, this study aimed to evaluate whether the antinociceptive property of 15d-PGJ₂ cream can be enhanced with microneedles (MNs). We found that topical application of 15d-PGJ₂ cream for 15min directly on the rat TMJ skin did not induce any significant antinociceptive effect. However, if MNs were inserted in the skin for 5min, removed, and then 15d-PGJ₂ cream was applied, a significant reduction in formalin-induced nociceptive behavior was observed. This reduction in nociception was comparable to an intra-TMJ injection of 15d-PGJ₂. A concentration-dependent effect of 15d-PGJ₂ was observed, with higher concentrations of 15d-PGJ₂ in the cream showing a more durable effect up to 8h. 15d-PGJ₂ cream associated with MNs also significantly reduced the release of tumor necrosis factor-α and interleukin-1 beta, which are pro-inflammatory cytokines. Our findings suggest that 15d-PGJ₂ cream associated with MNs provides antinociceptive and anti-inflammatory effect, and can offer a potential patient-friendly therapeutic option for pain control related to inflammatory disorders of the TMJ.

Association of Condylar Bone Quality with TMJ Osteoarthritis

The etiology and treatment of temporomandibular joint (TMJ) osteoarthritis (TMJOA) remain complex and unclear. Based on clinical observations, we hypothesized that low condylar bone quality is significantly correlated with TMJOA and explored this association in a cross-sectional study with human patients. A total of 254 postmenopausal female participants were included in this study. Radiographic findings from cone beam computed tomography (CBCT) and clinical symptoms were used to classify each TMJ data sample as healthy control ( n = 124) or TMJOA ( n = 130). Condylar bone mineral density (BMD) (computed tomography Hounsfield unit [CT HU]) and bone volume fraction (BV/TV) were measured and modeled as predictors of healthy control versus TMJOA status in multilevel logistic regression analyses. Both CT HU (adjusted odds ratio [AOR] = 0.9989, interquartile odds ratio [IOR] = 0.4206) and BV/TV (AOR= 0.8096, IOR = 0.1769) were negatively associated with TMJOA ( P = 0.049, 0.011, respectively). To assess the diagnostic performance of CT HU and BV/TV for identification of TMJOA, receiver operating characteristic (ROC) curves were plotted. The estimated areas under the curve (AUC) were 0.6622 for BV/TV alone, 0.6074 for CT HU alone, and 0.7136 for CT HU and BV/TV together. The model incorporating CT HU and BV/TV together had a significantly higher AUC than the models using BV/TV alone ( P = 0.038) or HU alone ( P = 0.021). In conclusion, we found that low condylar bone quality was significantly correlated with TMJOA development and that condylar CT HU and BV/TV can be used together as a potential diagnostic tool for TMJOA. Careful clinical evaluation of the condyle coupled with appropriate radiographic interpretation would thus be critical for the early detection of TMJOA.

Longitudinal Stability of Common TMJ Structural Disorders

The longitudinal course of temporomandibular joint (TMJ) disc displacement (DD) and degenerative joint disease (DJD) has never been conclusively described with magnetic resonance imaging and computed tomography, respectively. This 8-y observational study's objective was to assess the longitudinal stability of DD and DJD among 401 subjects. The Validation Project provided baseline measures; follow-up was performed in the TMJ Impact Project. With magnetic resonance imaging, 2 radiologists rendered a consensus diagnosis of normal/indeterminate, DD with reduction, or DD without reduction. Computed tomography consensus diagnoses included normal/indeterminate, grade 1 DJD, or grade 2 DJD. Radiologist reliability was assessed by kappa; a Hui-Walter model was used to estimate, after accounting for diagnostic disagreement, the frequency of diagnostic progression and reversal. Permutation tests were used to test the statistical influence of concurrent baseline diagnoses on diagnostic changes at follow-up. Of 789 baseline joint-specific soft tissue diagnoses of DD, 598 (76%) joints showed no change; 109 (14%) demonstrated progression; and 82 (10%) had reversal. Of 794 joints with baseline joint-specific hard tissue diagnoses of DJD, progression was observed in 122 (15%) joints, no change in 564 (71%), and reversal in 108 (14%). Radiologist reliability (kappa) was 0.73 (95% CI, 0.64 to 0.83) for DD and 0.76 (95% CI, 0.68 to 0.83) for DJD. After accounting for the influence of diagnostic disagreement, progression of hard tissue diagnoses in the right TMJ occurred in 15.2% of subjects (95% CI, 10.5% to 20.8%) and reversal in 8.3% (95% CI, 4.9% to 12.3%); results were similar for soft tissue diagnoses and the left TMJ. Concurrent baseline soft tissue diagnoses were associated with hard tissue diagnostic changes at follow-up ( P < 0.0001). Baseline hard tissue diagnoses showed no statistical association with soft tissue changes at follow-up ( P = 0.11). Longitudinally, 76% of baseline TMJ soft tissue diagnoses and 71% of the baseline hard tissue diagnoses remained stable. Diagnostic reversal and progression were confirmed for both soft and hard tissues.