The Relationship Between Temporomandibular Joint Synovitis and Adhesions: Pathogenic Mechanisms and Clinical Implications for Surgical Management

Otological symptoms in patients with rheumatoid arthritis of the temporomandibular joint

OBJECTIVE

The aim of the current study was to describe the pattern of otological symptoms in patients with rheumatoid arthritis (RA), having clinical temporomandibular joint (TMJ) involvement. This issue had not been previously addressed.

METHODS

A questionnaire and examination findings protocol was applied for 141 patients with RA and 141 control subjects.

RESULTS

Otological symptoms (otalgia, hearing loss, tinnitus, and vertigo), all had a significantly higher incidence in RA patients, compared to control subjects (P = .001).

CONCLUSION

The onset and maintenance of otological symptoms in patients with TMJ involvement by RA probably result from peripheral, as well as central nervous system alterations in sensory stimuli programming.

A comparative analysis between intra articular injections of injectable platelet rich fibrin versus platelet rich plasma in the management of temporomandibular disorders: A randomized control trial

Background

Platelet concentrate has become an increasingly popular alternative source of growth factors for several types of dental and surgical procedures. It improves healing and stimulates cell proliferation, matrix remodeling, and angiogenesis. The injectable platelet-rich fibrin (i-PRF) has various advantages over platelet-rich plasma (PRP). The aim of our study was to evaluate the efficacy of intra-articular injections of i-PRF versus PRP in the management of temporomandibular disorders (TDMs).

Method

The prospective randomized study involved 14 patients (N = 28 joints) of internal derangement between the age groups of 20 to 50 years divided randomly into two groups with seven patients (N = 14 joints) in each group. For all the patients, arthrocentesis was carried out in the first sitting followed by intra-articular injections of PRP and i-PRF in group I and group II, respectively, at 1-month interval for 6 months. A single surgeon has performed the procedure. All patients were assessed clinically for pain, maximal mouth opening (MMO), lateral movement, protrusive movement, and joint sounds and radiographically for disc position and joint effusion (JE).

Results

Pain reduction, MMO, lateral movement, protrusive movement, and joint sounds were significant in both groups with more significance in group II. Disc position had improved toward normal in both groups and showed significant changes in both groups at the 9-month follow-up with better results in group II.

Conclusion

PRP and i-PRF injections are regarded as simple and safe methods with potential beneficial effects and are cost-effective. In this preliminary study, i-PRF has been found to be scoring better in terms of efficacy over PRP across all set parameters.

Temporomandibular disorder: A previously unreported complication of chronic suppurative otitis media

OBJECTIVE

The aim of the current clinical study was to test the hypothesis that chronic suppurative otitis media (CSOM) might be significantly associated with signs of temporomandibular joint (TMJ) internal derangement.

METHODS

The study involved 79 patients with CSOM and 79 control subjects. The TMJ was clinically examined in both groups.

RESULTS

Signs of internal derangement of the TMJ(s) were found in 67.1% of CSOM patients versus 26.6% of control subjects (p = .001).

CONCLUSION

CSOM may be associated with the extension of the inflammatory process into the TMJ, thereby predisposing to internal derangement of the joint.

Mechanical Loading Disrupts Focal Adhesion Kinase Activation in Mandibular Fibrochondrocytes During Murine Temporomandibular Joint Osteoarthritis

PURPOSE

Mechanical overloading is a key initiating condition for temporomandibular joint (TMJ) osteoarthritis (OA). The integrin-focal adhesion kinase (FAK) signaling axis is implicated in the mechanobiological response of cells through phosphorylation at Tyr397 (pFAK) but poorly defined in TMJ health and disease. We hypothesize that mechanical overloading disrupts TMJ homeostasis through dysregulation of FAK signaling.

MATERIALS AND METHODS

To assess if FAK and pFAK are viable clinical targets for TMJ OA, peri-articular tissues were collected from patients with TMJ OA receiving a total TMJ replacement. To compare clinical samples with preclinical in vivo studies of TMJ OA, the joints of c57/bl6 mice were surgically destabilized and treated with and without inhibitor of pFAK (iFAK). FAK signaling and TMJ OA progression was evaluated and compared using RT-PCR, western blot, immunohistochemistry, and histomorphometry. To evaluate mechanical overloading in vitro, primary murine mandibular fibrochondrocytes were seeded in a 4% agarose-collagen scaffold and loaded in a compression bioreactor with and without iFAK.

RESULTS

FAK/pFAK was mostly absent from the articular cartilage layer in the clinical sample and suppressed on the central condyle and elevated on the lateral and medial condyle in murine TMJ OA. In vitro, compressive loading lowered FAK/pFAK levels and elevated the expression of TGFβ, NG2, and MMP-13. iFAK treatment suppressed MMP13 and Col6 and elevated TGFβ, NG2, and ACAN in a load independent manner. In vivo, iFAK treatment moderately attenuated OA progression and increased collagen maturation.

CONCLUSION

These data illustrate that FAK/pFAK is implicated in the signaled dysfunction of excessive mechanical loading during TMJ OA and that iFAK treatment can moderately attenuate the progression of cartilage degeneration in the mandibular condyle.

Is There a Relationship Between Age, Personal Factors or Surgical Findings, and Outcome After Temporomandibular Joint Arthroscopy?

PURPOSE

The variables involved in prognosis after treatment of internal derangement (ID) of the temporomandibular joint (TMJ) are unclear. The purpose of this study was to estimate the frequency and identify which factors are associated with treatment success (or failure) among patients with ID managed with arthroscopy.

MATERIAL AND METHODS

A retrospective cohort study was carried out of patients undergoing TMJ arthroscopy over a 9-year-period. The predictor variable was composed of a set of demographic, clinical, and operative findings, including, as primary variable, the patient's age. The primary outcome variable was based on the American Association of Oral and Maxillofacial Surgery (AAOMS) criteria of pain (measured by visual analogue scale (VAS)) and maximal interincisal opening (MIO) defined as VAS ≤ 3 and MIO greater 35 mm and grouped as success or failure. The improvement in pain and functional values were compared with the age by using the Pearson correlation coefficient, whereas categorical variables were tested using chi-squared analysis, and mean values were compared with Student t-test or ANOVA. Subsequently, a logistic regression model was used, and the odds ratios (OR) of the evaluated comparisons were calculated.

RESULTS

A total of 212 patients were included in this study. In terms of arthroscopic findings, the presence of severe chondromalacia, adhesions or disc perforation (P < .001), was related with older patients. However, there was no statistically significant correlation between age and the postoperative improvement referred to pain or MIO. According to the AAOMS criteria, the procedure was successful in 54.24% of the cases. Two factors were related with a favorable outcome in the adjusted regression analysis: a higher presurgical MIO (OR 0.91, P < .001) and the presence of adhesions (OR 0.41, P = .003).

CONCLUSION

Age has no influence on the outcome after arthroscopy. A higher presurgical MIO and the presence of adhesions provide, in the long-term, a favorable prognosis.

Effect of dextrose phonophoresis versus pulsed electromagnetic field on temporomandibular dysfunction: A randomized, controlled study

OBJECTIVE

This study investigated and compared the efficacy of dextrose phonophoresis and Pulsed Electromagnetic Field (PEMF) on pain, range of motion (ROM) and function in patients with Temporomandibular Dysfunction (TMD).

METHODS

45 patients with TMD aging from 25 to 45 years, with mean age 29 ± 2.5 years were included in this study, they were assigned randomly into 3 equal groups each contain fifteen TMJ dysfunction patients. Group (A) in which each patient received 50% dextrose phonophoresis for 5 min and therapeutic ultrasound for 5 min, Group (B) in which each patient received Pulsed Electromagnetic Field (PEMF) with frequency of 50 HZ for 50 min, and traditional physiotherapy ultrasound for 5 min, while in the control group (C) the patients received traditional physiotherapy ultrasound for 5 min only, the frequency of treatment session in the three groups was 3 days per week for 4 weeks. The assessment tools were visual analog scale (VAS) for pain evaluation, plastic ruler for TMJ ROM measurements while Fonseca's questionnaire was used for evaluation of TM function at baseline and 4 weeks later.

RESULTS

Paired t-test for comparison between pre and post treatment measurements in each group showed significant decrease pain as well as improvement of ROM and Fonseca's questionnaire in group A and B than placebo group.

CONCLUSIONS

The results found that both dextrose phonophoresis and PEMF have beneficial effects considering pain, ROM and function in patients with (TMD).

Osteoimmunology of Oral and Maxillofacial Diseases: Translational Applications Based on Biological Mechanisms

The maxillofacial skeleton is highly dynamic and requires a constant equilibrium between the bone resorption and bone formation. The field of osteoimmunology explores the interactions between bone metabolism and the immune response, providing a context to study the complex cellular and molecular networks involved in oro-maxillofacial osteolytic diseases. In this review, we present a framework for understanding the potential mechanisms underlying the immuno-pathobiology in etiologically-diverse diseases that affect the oral and maxillofacial region and share bone destruction as their common clinical outcome. These otherwise different pathologies share similar inflammatory pathways mediated by central cellular players, such as macrophages, T and B cells, that promote the differentiation and activation of osteoclasts, ineffective or insufficient bone apposition by osteoblasts, and the continuous production of osteoclastogenic signals by immune and local stromal cells. We also present the potential translational applications of this knowledge based on the biological mechanisms involved in the inflammation-induced bone destruction. Such applications can be the development of immune-based therapies that promote bone healing/regeneration, the identification of host-derived inflammatory/collagenolytic biomarkers as diagnostics tools, the assessment of links between oral and systemic diseases; and the characterization of genetic polymorphisms in immune or bone-related genes that will help diagnosis of susceptible individuals.

Two-photon fluorescence and second harmonic generation characterization of extracellular matrix remodeling in post-injury murine temporomandibular joint osteoarthritis

End stage temporomandibular joint osteoarthritis (TMJ-OA) is characterized by fibrillations, fissures, clefts, and erosion of the mandibular condylar cartilage. The goal of this study was to define changes in pericellular and interterritorial delineations of the extracellular matrix (ECM) that occur preceding and concurrent with the development of this end stage degeneration in a murine surgical instability model. Two-photon fluorescence (TPF) and second harmonic generation (SHG) microscopy was used to evaluate TMJ-OA mediated changes in the ECM. We illustrate that TPF/SHG microscopy reconstructs the three-dimensional network of key fibrillar and micro-fibrillar collagens altered during the progression of TMJ-OA. This method not only generates spatially distinct pericellular and interterritorial delineations of the ECM but distinguishes early and end stage TMJ-OA by signal organization, orientation, and composition. Early stage TMJ-OA at 4- and 8-weeks post-injury is characterized by two structurally distinct regions containing dense, large fiber collagens and superficial, small fiber collagens rich in types I, III, and VI collagen oriented along the mesiodistal axis of the condyle. At 8-weeks post-injury, type VI collagen is locally diminished on the central and medial condyle, but the type I/III rich superficial layer is still present. Twelve- and 16-weeks post-injury mandibular cartilage is characteristic of end-stage disease, with hypocellularity and fibrillations, fissures, and clefts in the articular layer that propagate along the mediolateral axis of the MCC. We hypothesize that the localized depletion of interterritorial and pericellular type VI collagen may signify an early marker for the transition from early to end stage TMJ-OA, influence the injury response of the tissue, and underlie patterns of degeneration that follow attritional modes of failure.

Potential Role of Rebamipide in Osteoclast Differentiation and Mandibular Condylar Cartilage Homeostasis

Background:

Temporomandibular joint osteoarthritis (TMJ-OA) is a degenerative disease that involves changes in subchondral bone and progressive degradation of cartilage. Currently, rebamipide, a gastroprotective drug, is administered to protect gastric mucosa and accelerate ulcer healing.

Objectives:

Recent studies have shown that rebamipide also attenuates cartilage degeneration by suppressing oxidative damage and inducing homeostasis of the extracellular matrix of articular chondrocytes. Regarding the latter, reduced expression of cathepsin K, NFATc1, c-Src, and integrin β3, and increased expression of nuclear factor-kappa B, have been found to be mediated by the transcription factor, receptor activator of nuclear factor kappa-B ligand (RANKL).

Methods:

Treatment with rebamipide was also found to activate, mitogen-activated protein kinases such as p38, ERK, and JNK to reduce osteoclast differentiation. Taken together, these results strongly indicate that rebamipide mediates inhibitory effects on cartilage degradation and osteoclastogenesis in TMJ-OA.

Results and Conclusion:

Here, we highlight recent evidence regarding the potential for rebamipide to affect osteoclast differentiation and TMJ-OA pathogenesis. We also discuss the potential role of rebamipide to serve as a new strategy for the treatment of TMJ-OA.

Long-Term Outcome of Arthrocentesis Plus Hyaluronic Acid Injection in Patients With Wilkes Stage II and III Temporomandibular Joint Internal Derangement

OBJECTIVE

Arthrocentesis is a minimally invasive procedure used to manage temporomandibular joint (TMJ) internal derangement (ID). This study evaluated the outcome of arthrocentesis in patients with Wilkes stage II and III TMJ ID.

PATIENTS AND METHODS

This retrospective study enrolled 50 patients who underwent arthrocentesis in 2011 and 2012 at the Karadeniz Technical University, Faculty of Dentistry, Department of Oral and Maxillofacial Surgery, Turkey. In total, 43 patients underwent unilateral arthrocentesis, whereas 7 patients had bilateral arthrocentesis. The clinical parameters recorded were pain (visual analogue scale [VAS] 0-100 mm during movement), chewing function efficacy (VAS 0-100), clicking sounds, and mandibular movements, including maximum interincisal opening (MIO), lateral excursion, and protrusion. All the parameters were recorded preoperatively, and 1, 3, 6, and 24 months after treatment.

RESULTS

The MIO, lateral excursion, and protrusion were significantly greater than preoperatively in all the patients. Pain declined significantly postoperatively. The patients in Wilkes III group had greater improvement in mandibular movement and pain than the patients in Wilkes II group.

CONCLUSION

Arthrocentesis was reliable for treating both Wilkes II and III TMJ ID, and the treatment results were better in Wilkes III patients.

Gene Expression Profiling of IL-17A-Treated Synovial Fibroblasts from the Human Temporomandibular Joint

Synovial fibroblasts contribute to the inflammatory temporomandibular joint under pathogenic stimuli. Synovial fibroblasts and T cells participate in the perpetuation of joint inflammation in a mutual activation feedback, via secretion of cytokines and chemokines that stimulate each other. IL-17 is an inflammatory cytokine produced primarily by Th17 cells which plays critical role in the pathogenesis of numerous autoimmune and inflammatory diseases. Here, we investigated the roles of IL-17A in temporomandibular joint disorders (TMD) using genome-wide analysis of synovial fibroblasts isolated from patients with TMD. IL-17 receptors were expressed in synovial fibroblasts as assessed using real-time PCR. Microarray analysis indicated that IL-17A treatment of synovial fibroblasts upregulated the expression of IL-6 and chemokines. Real-time PCR analysis showed that the gene expression of IL-6, CXCL1, IL-8, and CCL20 was significantly higher in IL-17A-treated synovial fibroblasts compared to nontreated controls. IL-6 protein production was increased by IL-17A in a time- and a dose-dependent manner. Additionally, IL-17A simulated IL-6 protein production in synovial fibroblasts samples isolated from three patients. Furthermore, signal inhibitor experiments indicated that IL-17-mediated induction of IL-6 was transduced via activation of NFκB and phosphatidylinositol 3-kinase/Akt. These results suggest that IL-17A is associated with the inflammatory progression of TMD.

Arthroscopic discopexy is effective in managing temporomandibular joint internal derangement in patients with Wilkes stage II and III

PURPOSE

Disc repositioning for temporomandibular joint (TMJ) internal derangement (ID) is a well-established surgical technique with variable success. The purpose of the present study was to assess the outcomes after arthroscopic disc repositioning (discopexy) for TMJ ID.

PATIENTS AND METHODS

This was a prospective, cohort, single-institutional clinical study. The study included patients with TMJ ID in whom diagnostic arthroscopy had failed. These patients were presented and treated at Miami Oral and Maxillofacial Surgery, Baptist Hospital (Miami FL). The predictive variable was the Wilkes diagnostic categories, presented in 2 groups: II and III versus IV and V. The primary outcome variable was the absence of joint pain at 12 months postoperatively. The secondary outcome variables included joint function, maximum interincisal opening, medication use, joint loading sign, and muscle pain. The patients were followed for 1 year postoperatively. The statistical analyses included paired and independent sample Student's t test, χ(2) test, and logistic regression analysis.

RESULTS

A total of 32 subjects (42 joints), with a mean age of 31 years, were included in the present study; 28 (87.5%) were women. Of the 42 joints, 71.4% were classified as Wilkes stage II and III. A successful outcome was seen in 69% of the studied subjects and in 86.7% of the Wilkes II and III group versus 25% of the Wilkes IV and V group (P = .001).

CONCLUSION

The results of the present study have shown that TMJ arthroscopic discopexy is an effective and predictable treatment of patients with TMJ ID in whom primary TMJ arthroscopy failed. Our results have also shown that patients with Wilkes II or III TMD will have the most successful outcome.

Arthrocentesis and temporomandibular joint disorders: clinical and radiological results of a prospective study

Purpose. We evaluated the efficacy of arthrocentesis in the treatment of temporomandibular joint (TMJ) disorders. Material and Methods. In this prospective clinical case series, 30 consecutive patients with TMJ disorders underwent arthrocentesis using saline and sodium hyaluronate injections. Outcome measures were TMJ pain, maximum mouth opening (MMO), joint noises, and anatomical changes in the TMJ architecture. Patients were evaluated using cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI) at the beginning of treatment and 60 days after the last arthrocentesis. Pretreatment and posttreatment clinical parameters were compared using paired and unpaired t-tests, and McNemar's test was used to evaluate CBCT and MRI changes (P < 0.05). Results. At 1-year follow-up examinations, visual analogue scale scores indicated that pain was reduced significantly and mean postoperative MMO was increased significantly. CBCT findings showed no significant change, and MRI showed only slight reductions in inflammatory signs. Conclusions. Within the limitations of this study, we can conclude that arthrocentesis is a simple, minimally invasive procedure with a relatively low risk of complications and significant clinical benefits in patients with TMJ disorders. This trial is registered with NCT01903512.

Evaluation of efficacy of arthrocentesis (with normal saline) with or without sodium hyaluronate in treatment of internal derangement of TMJ - A prospective randomized study in 20 patients

PURPOSE

To compare the outcome of arthrocentesis alone and arthrocentesis with sodium hyaluronate in internal derangement of TMJ.

MATERIALS AND METHODS

20 patients of disc displacement with reduction of TMJ were randomized into 2 experimental groups. Control group of patients received arthrocentesis alone and study group of patients received arthrocentesis with sodium hyaluronate. Patients TMJ status and clinical symptoms were evaluated for 6 months follow up. The clinical parameter recorded were maximal mouth opening (MMO), lateral excursions (right and left side), protrusive movement, joint noises, and pain (at rest, at function).

RESULTS

When 2 groups are compared there was no statistically significant difference in terms of inter-incisal opening, lateral excursion, protrusive movement, joint noises and pain however the group with sodium hyaluronidase has shown better results than the control group.

CONCLUSION

Both study and control group found to be statistically insignificant but patient who were in the group of arthrocentesis with admission of sodium hyaluronidase had better results.

Expression of VEGF-receptors in TMJ synovium of rabbits with experimentally induced internal derangement

Our aim was to evaluate the expression of vascular endothelial growth factor receptors (VEGFRs) in the synovium of the temporomandibular joints (TMJ) of rabbits with experimentally induced internal derangement. Internal derangement was experimentally induced in 52 rabbit TMJ, and established on the right side of TMJ while the left side was used as the control. Each joint and its control was evaluated by magnetic resonance imaging (MRI) and endoscopy. The synovial tissues on both sides were harvested after one, two, three, and four weeks. The expression of VEGFRs mRNA was investigated in the experimental joint and its control using real-time polymerase chain reaction (PCR). Internal derangement was successfully confirmed in 45 of the 52 of the experimental joints (87%) on the right side by MRI and endoscopy. In the first and fourth week, the VEGFR-2 mRNA expression was higher in the experimental joints than in the controls (P=0.008 and P=0.02). Meanwhile, the VEGFR-1 mRNA expression was up-regulated in the experimental group compared with the controls during the fourth week (P=0.02). However, we found no significant differences in VEGFR-3 mRNA expression in the two groups during the first and fourth weeks. During the second and third weeks, the mRNA expression of the three receptors did not differ significantly among the groups. Our data have shown increased expression of VEGFR-1 and VEGFR-2 mRNA in the synovium of rabbit TMJ with internal derangement, which indicates that VEGFR-1 and VEGFR-2 may have important roles in the processes of internal derangement and formation of adhesions.

Arthrocentesis for the treatment of internal derangement of the temporomandibular joint

OBJECTIVE

The study aims to evaluate the efficacy of arthrocentesis in the treatment of internal derangement of the temporomandibular joint (TMJ).

STUDY DESIGN

Thirty patients with TMJ internal derangement underwent arthrocentesis using saline. Pain using visual analog scale, maximum mouth opening, joint noises and mandible deviation were documented pre-operatively and post-operatively. Patients were followed for 1 year. Statistical analysis of pain was done by Wilcoxon signed Rank's test and dysfunction by students paired t test.

RESULTS

The mean pre-operative pain was 4.8 ± 2.65 and post-operatively at 1 year was 0.27 ± 0.45 with an average decrease of 4.72 (P = 0.000). The mean maximal mouth opening pre-operatively was 29.8 ± 2.35 mm and post-operatively 41.9 ± 2.48 mm at 1 year. The mean increase in the mouth opening was 12.1 ± 3.0 mm (P = 0.000).

CONCLUSION

Arthrocentesis is simple, minimally invasive procedure with less risk of complications and significant benefits in patients with TMJ internal derangement.

Temporomandibular joint pain and synovial fluid analysis: a review of the literature

The pathophysiology of temporomandibular joint pain is not well understood. A significant amount of research has been conducted to evaluate synovial fluid in these patients and in healthy controls. Qualitative and quantitative analyses of the synovial fluid have shown a significant difference between these groups. A multitude of inflammatory mediators and degradation products have been identified. The concentration of these products has been shown to correlate with several clinical parameters including pain, chronicity, severity of degenerative change, and response to treatment. A common inflammatory pathway would appear to be involved in most patients. At the present time, synovial fluid analysis does not have the sensitivity or specificity to allow specific diagnoses and targeted treatment. Continued research with the specific aim of establishing more appropriate therapeutic modalities based on the biochemical pathways is warranted.

Internal derangements of the temporomandibular joint

This article discusses several types of internal derangements of the temporomandibular joint. It includes definitions, clinical characteristics, and management options. Nonsurgical and surgical treatment strategies are discussed taking into consideration the latest evidence-based literature.

Association between anterior tooth wear and temporomandibular disorder pain in a German population

STATEMENT OF PROBLEM

Bruxism is purported to be a risk factor for temporomandibular disorder (TMD) pain, but the association requires clarification.

PURPOSE

The purpose of this study was to investigate the relation between anterior tooth wear as an indicator for bruxism and the presence of TMD pain.

MATERIAL AND METHODS

Study subjects included 646 participants (age range 35 to 44 years) of a national oral health survey in Germany. Anterior tooth wear was registered for each anterior tooth with a 4-point scale (none, mild, moderate, and severe wear). Temporomandibular disorder was defined as self-reported pain in the face, jaw muscles, and/or temporomandibular joint (TMJ) during the last month, according to either the German version of the Research Diagnostic Criteria for Temporomandibular Disorders or the response to a question about pain in the masticatory muscles or the TMJ according to the Helkimo-Index. A multiple logistic regression analysis, controlling for the effects of age and gender, investigated the linear relationship between increased tooth wear and the risk of TMD pain.

RESULTS

After adjusting for age and gender, an odds ratio of 1.11 (95% confidence interval: 0.7-1.8) indicated that the risk of TMD pain increased an estimated 11% per unit increase of tooth wear. There was no statistically significant or clinically relevant relationship between a linear increase of tooth wear and risk of TMD pain.

CONCLUSION

Anterior tooth wear was not associated with self-reported TMD pain in 35- to 44-year-old subjects. Using anterior tooth wear as an indicator for long-term bruxing behavior, a clinically relevant dose-response relationship between this type of bruxism and TMD pain does not appear to exist.

Temporomandibular joint pain and dysfunction

Pain caused by temporomandibular disorders originates from either muscular or articular conditions, or both. Distinguishing the precise source of the pain is a significant diagnostic challenge to clinicians, and effective management hinges on establishing a correct diagnosis. This paper examines terminology and regional anatomy as it pertains to functional and dysfunctional states of the temporomandibular joint and muscles of mastication. A review of the pathophysiology of the most common disorders is provided. Trends in evaluation, diagnosis, treatment, and research are presented.