Temporomandibular disorders (TMD) are a class of degenerative musculoskeletal conditions associated with morphologic and functional deformities that affect up to 25% of the population, but their ...etiology and progression are poorly understood and, as a result, treatment options are limited. In up to 70% of cases, TMD are accompanied by malpositioning of the temporomandibular joint (TMJ) disc, termed "internal derangement." Although the onset is not well characterized, correlations between internal derangement and osteoarthritic change have been identified. Because of the complex and unique nature of each TMD case, diagnosis requires patient-specific analysis accompanied by various diagnostic modalities. Likewise, treatment requires customized plans to address the specific characteristics of each patient's disease. In the mechanically demanding and biochemically active environment of the TMJ, therapeutic approaches that can restore joint functionality while responding to changes in the joint have become a necessity. One such approach, tissue engineering, which may be capable of integration and adaptation in the TMJ, carries significant potential for the development of repair and replacement tissues. The following review presents a synopsis of etiology, current treatment methods, and the future of tissue engineering for repairing and/or replacing diseased joint components, specifically the mandibular condyle and TMJ disc. An analysis of native tissue characterization to assist clinicians in identifying tissue engineering objectives and validation metrics for restoring healthy and functional structures of the TMJ is followed by a discussion of current trends in tissue engineering.
Temporomandibular disorders (TMDs) have the highest prevalence in women of reproductive age. The role of estrogen in TMDs and especially in TMDs related pain is not fully elucidated. Voltage-gated ...sodium channel 1.7 (Nav1.7) plays a prominent role in pain perception and Nav1.7 in trigeminal ganglion (TG) is involved in the hyperalgesia of inflamed Temporomandibular joint (TMJ). Whether estrogen could upregulate trigeminal ganglionic Nav1.7 expression to enhance hyperalgesia of inflamed TMJ remains to be explored.
Estrous cycle and plasma levels of 17β-estradiol in female rats were evaluated with vaginal smear and enzyme linked immunosorbent assay, respectively. Female rats were ovariectomized and treated with 17β-estradiol at 0 μg, 20 μg and 80 μg, respectively, for 10 days. TMJ inflammation was induced using complete Freund's adjuvant. Head withdrawal thresholds and food intake were measured to evaluate the TMJ nociceptive responses. The expression of Nav1.7 in TG was examined using real-time PCR and western blot. The activity of Nav1.7 promoter was examined using luciferase reporter assay. The locations of estrogen receptors (ERα and ERβ), the G protein coupled estrogen receptor (GPR30), and Nav1.7 in TG were examined using immunohistofluorescence.
Upregulation of Nav1.7 in TG and decrease in head withdrawal threshold were observed with the highest plasma 17β-estradiol in the proestrus of female rats. Ovariectomized rats treated with 80 μg 17β-estradiol showed upregulation of Nav1.7 in TG and decrease in head withdrawal threshold as compared with that of the control or ovariectomized rats treated with 0 μg or 20 μg. Moreover, 17β-estradiol dose-dependently potentiated TMJ inflammation-induced upregulation of Nav1.7 in TG and also enhanced TMJ inflammation-induced decrease of head withdrawal threshold in ovariectomized rats. In addition, the estrogen receptor antagonist, ICI 182,780, partially blocked the 17β-estradiol effect on Nav1.7 expression and head withdrawal threshold in ovariectomized rats. ERα and ERβ, but not GPR30, were mostly co-localized with Nav1.7 in neurons in TG. In the nerve growth factor-induced and ERα-transfected PC12 cells, 17β-estradiol dose-dependently enhanced Nav1.7 promoter activity, whereas mutations of the estrogen response element at -1269/-1282 and -1214/-1227 in the promoter completely abolished its effect on the promoter activity.
Estradiol could upregulate trigeminal ganglionic Nav1.7 expression to contribute to hyperalgesia of inflamed TMJ.
Objectives
To review the literature and summarize the evidence of temporomandibualar joint (TMJ) disorders (TMDs) in older adults, focusing on clinical manifestations of TMDs in older adults, ...highlighting the incidence and sexual dimorphism of TMJ degeneration and the role of sex hormones in this process, and providing potential treatment options for TMD in older adults.
Design
Two review authors performed the literature search, study inclusion, and data extraction. PubMed, Embase, and Google scholar were searched for literature until August 2017 (Figure ). We adopted a combination of Medical Subject Headings with related free text words for the search in PubMed and optimized the search in other search engines.
Results
Traditionally, it was believed that TMDs predominantly affected women of childbearing age, but recent large studies in Europe and the United States have shown that the prevalence of TMD peaks after childbearing age (45–64) and then gradually decreases with age, although not much is known about the disease in older adults.
Conclusion
Most older adults have TMJ degeneration, which affects women more than men. In most older adults, the symptoms of TMD are mild and self‐limiting and can usually be treated with self management.
Temporomandibular disorders (TMD) are a heterogeneous group of musculoskeletal and neuromuscular conditions involving the temporomandibular joint complex, and surrounding musculature and osseous ...components. TMD affects up to 15% of adults, with a peak incidence at 20 to 40 years of age. TMD is classified as intra-articular or extra-articular. Common symptoms include jaw pain or dysfunction, earache, headache, and facial pain. The etiology of TMD is multifactorial and includes biologic, environmental, social, emotional, and cognitive triggers. Diagnosis is most often based on history and physical examination. Diagnostic imaging may be beneficial when malocclusion or intra-articular abnormalities are suspected. Most patients improve with a combination of noninvasive therapies, including patient education, self-care, cognitive behavior therapy, pharmacotherapy, physical therapy, and occlusal devices. Nonsteroidal anti-inflammatory drugs and muscle relaxants are recommended initially, and benzodiazepines or antidepressants may be added for chronic cases. Referral to an oral and maxillofacial surgeon is indicated for refractory cases.
Tissue engineering potentially offers new treatments for disorders of the temporomandibular joint which frequently afflict patients. Damage or disease in this area adversely affects masticatory ...function and speaking, reducing patients' quality of life. Effective treatment options for patients suffering from severe temporomandibular joint disorders are in high demand because surgical options are restricted to removal of damaged tissue or complete replacement of the joint with prosthetics. Tissue engineering approaches for the temporomandibular joint are a promising alternative to the limited clinical treatment options. However, tissue engineering is still a developing field and only in its formative years for the temporomandibular joint. This review outlines the anatomical and physiological characteristics of the temporomandibular joint, clinical management of temporomandibular joint disorder, and current perspectives in the tissue engineering approach for the temporomandibular joint disorder. The tissue engineering perspectives have been categorized according to the primary structures of the temporomandibular joint: the disc, the mandibular condyle, and the glenoid fossa. In each section, contemporary approaches in cellularization, growth factor selection, and scaffold fabrication strategies are reviewed in detail along with their achievements and challenges.
The aim of this study was to assess the various outcomes of arthroscopic discopexy compared to the natural course of anterior disc displacement (ADD) longitudinally in the same patients. A ...retrospective review was performed of 108 patients (152 joints) who experienced the natural course of ADD for a period of time and then underwent arthroscopic discopexy. The outcome was evaluated clinically and by magnetic resonance imaging. The natural course of ADD showed significant deterioration in pain, diet, and quality of life, and also a significant reduction in inter-incisal opening (all P < 0.001), while significant improvements in all clinical parameters were observed at the final postoperative follow-up (all P < 0.001, compared to the last preoperative visit). During the natural course, there was a significant shortening of condylar height, mandibular height, and disc length, and an increase in disc displacement distance (all P < 0.001). Postoperative follow-up revealed the restoration of condylar height and mandibular height, and all discs were significantly repositioned with an increased disc length (unfolded) (all P < 0.001). Bearing in mind the assumption of a low evidence base due to bias resulting from the retrospective non-double-blinded study design and the variable duration of the natural disease course prior to surgery, this study found that the natural course of ADD led to degenerative changes in the joint structures and clinical symptoms, whereas arthroscopic discopexy led to a restoration of the bony structures and the alleviation of clinical symptoms.
To evaluate the effect of temporomandibular joint (TMJ) disc repositioning and post-operative functional splint for the treatment of anterior disc displacement (ADD) in juvenile patients with Class ...II malocclusion.
Juvenile patients (≤20 years) who had bilateral TMJ ADD with and Class II malocclusion treated by disc repositioning and functional splints were included in the study. Magnetic resonance imaging (MRI) and cephalometric radiographs before surgery (T0), immediately after surgery (T1) and more than 3 months after surgery (T3) were obtained in all patients. Cephalometric values including condylar height, overjet, SNA, SNB and pogonion position etc. were measured and compared before and after disc repositioning by statistical analysis. Fourteen patients (13 female, 1 male) were included in this study. Their average age was 16.7 years (range, 12–20 years).
Seven patients with 14 joints had an MRI at least 6 months (6–24 months, mean 14.3) prior to disc repositioning. When compared to the MRI taken just prior to surgery, of those 14 joints, 9 condyles (64.3%) had evidence of bone resorption, 5 condyles (35.7%) had new bone formation mostly at the posterior part of the condyle (21.4%). These MRIs showed the condylar height was reduced 0.81 mm ± 0.61 (P = 0.013). Pre-operative cephalometric radiographs showed increased overjet (P = 0.039). The mean post-operative follow-up was 9.4 months (range, 4–13 months). Postoperative MRI showed the condylar height increased 1.74 ± 0.98 mm after disc repositioning (P < 0.001). Newly generated bone was observed on all condyles. 84.6% of the new bone was formed on the superior and posterior-anterior surfaces. Postoperative cephalometric radiographs showed the SNB angle increased 1.83 ± 1.56°(P < 0.001), pogonion position (pg’-G′) moved anteriorly 2.18 ± 3.13 mm (P = 0.028) and incisor overjet decreased 3.55 ± 1.86 mm (P < 0.001), whereas significant changes were not found in SNA, Sn - G Vert, Y-Axis, U1 SN, IMPA (L1-MP) and U1-L1 (P > 0.05).
Conservative treatment for ADD with Class II malocclusion in juvenile patients may cause condyle resorption and aggravate the dentofacial deformity. Disc repositioning combined with post-operative functional splints can effectively promote condylar growth and help correct the dentofacial deformity.
•Disc repositioning and functional splint as a new treatment of anterior disc displacement in juvenile patients with class II malocclusion.•Through MRI and cephalometric radiograph evaluation, this therapy can stimulate condylar regeneration and alleviate facial-oral deformity to make the further treatment easy.
The aim of this study was to determine the association between more advanced stages of temporomandibular joint (TMJ) intra-articular disorders (“TMJ intra-articular status”), representing a ...transition from normal joint structure to TMJ disc displacement with and without reduction (DDwR and DDwoR) to degenerative joint disease (DJD), and patient-reported outcomes of jaw pain, function, and disability (“TMD impact”). This cross-sectional study included 614 cases from the RDC/TMD Validation Project with at least one temporomandibular disorder (TMD) diagnosis. TMJ intra-articular status was determined by 3 blinded, calibrated radiologists using magnetic resonance imaging and computed tomography as one of normal joint structure, DDwR, DDwoR, or DJD, representing the subject’s most advanced TMJ diagnosis. TMD impact was conceptualized as a latent variable consisting of 1) pain intensity (Characteristic Pain Index from the Graded Chronic Pain Scale GCPS), 2) jaw function (Jaw Functional Limitation Scale), and 3) disability (Disability Points from GCPS). A structural equation model estimated the association of TMJ intra-articular status with the latent measure TMD impact as a correlation coefficient in all TMD cases (n = 614) and in cases with a TMD pain diagnosis (n = 500). The correlations between TMJ intra-articular status and TMD impact were 0.05 (95% confidence interval CI, −0.04 to 0.13) for all TMD cases and 0.07 (95% CI, −0.04 to 0.17) for cases with a pain diagnosis, which are neither statistically significant nor clinically relevant. Conceptualizing worsening of TMJ intra-articular disorders as 4 stages and characterizing impact from TMD as a composite of jaw pain, function, and disability, this cross-sectional study found no clinically significant association. Models of TMJ intra-articular status other than ours (normal structure → DDwR → DDwoR → DJD) should be explored.
Background
Foramen tympanicum (FT) is a defect located anterior‐inferior to the external acoustic meatus. We evaluated its prevalence, location, size, and relationship with temporomandibular joint ...(TMJ) disorders.
Methods
Cone beam computed tomography was performed for 200 patients who presented to the Karamanoğlu Mehmetbey University Ahmet Keleşoğlu Faculty of Dentistry Hospital. The location and size of the FT in the axial and sagittal planes were evaluated. Descriptive statistics were used to compare the study parameters among age and sex groups. Patients with FT were reevaluated by two maxillofacial surgeons at the study centre.
Results
In total, 200 images from 400 joints were examined. Unilateral and bilateral FT (19 9.5% and 8 4%, respectively) was detected in 35 (17.5%) images from 27 (13.5%) patients. Examinations were performed for TMJ disorders in 24 patients. Participants with bilateral defects had the highest rates of presence of sounds and ear pain on the left and right sides (p < .05).
Conclusion
Foramen tympanicum can lead to TMJ disorders and spread of tumours or infections from the external auditory canal to the infratemporal fossa. The increased prevalence of such disorders in patients with bilateral FT suggests an association between them.
Purpose: Interleukin-1 beta (IL-1β) is a cytokine that participates in the regulation of immune responses and inflammatory reactions. It is hypothesized that IL-1 levels may be elevated in patients ...suffering from temporomandibular joint dysfunction. The purpose of this study was to determine the association of IL-1β expression with TMD using an immunohistochemical approach to evaluate the joint disc.
Materials and methods: A total of 39 human temporomandibular joint disc samples were collected, with 31 samples in the test group. Nineteen of the test group samples were from discs of patients with anterior disc displacement with reduction, and 12 of the samples were from patients with anterior disc displacement without reduction. Eight control samples were used in the control group. The samples were immunostained and evaluated on both quantity and intensity of staining.
Results: There was a statistically significant difference (p < 0.05) between the control and test groups for both quantity and intensity of staining.
Conclusion: IL-1β plays a role in the inflammatory process and degradation of TMJ discs in patients with TMJ dysfunctions.