Etiological factors of temporomandibular joint disorders

Population Analysis of Masseter Muscle Tension Using Shear Wave Ultrasonography across Different Disease States

Objective: This study aimed to evaluate the distribution and trends of masseter muscle tension in patients with temporomandibular joint (TMJ) pain, examining gender-specific differences and the impact of various TMJ disorders. Methods: From January 2020 to June 2024, a total of 734 patients presenting with facial pain radiating to the head and neck, localized around and extending from the TMJ, were referred for ultrasonographic examination. After applying exclusion criteria, 535 patients (72.9%) were included in the study. The patient cohort consisted of 343 females (64.1%) and 192 males (35.9%), with muscle tension measured using the Aixplorer ultrasound system equipped with a shear wave device. Data were collected and analyzed across different age groups and TMJ conditions, including "no changes", "exudate", "arthrosis", and "disc displacement". Results: The study found that males exhibited higher muscle tension across all conditions, particularly in the "no changes" (40.4 kPa vs. 32.1 kPa, 25.9% higher) and "exudate" (38.5 kPa vs. 29.7 kPa, 29.6% higher) categories, indicating increased muscle strain and inflammation during middle age. In females, a trend of decreasing muscle tension with age was observed, with a significant reduction from 36.2 kPa in the 20-30 age group to 24.3 kPa in the 60-70 age group (32.9% reduction), suggesting a reduction in muscle mass or strength due to aging. Both genders showed high muscle tension in the presence of exudate, with females peaking in the 40-50 age group at 37.1 kPa and males peaking earlier in the 20-30 age group at 41.2 kPa (10.9% higher in males), highlighting potential gender differences in inflammatory response. In the arthrosis group, males displayed a consistent increase in muscle tension with age, peaking at 37.5 kPa in the 50-60 age group (50.7% increase from the 20-30 age group), while females showed high tension, particularly in the 40-50 age group at 31.0 kPa (82.4% higher compared to the 20-30 age group), indicating the need for targeted joint health interventions in middle-aged women. Conclusions: This study reveals significant gender-specific differences in masseter muscle tension among patients with TMJ pain. Males were found to be more affected by muscle strain and inflammation during middle age, whereas females showed a significant decrease in muscle tension with age. The presence of exudate significantly impacted muscle tension across all age groups for both genders. These findings underscore the importance of tailored clinical interventions and preventive strategies to manage TMJ disorders effectively.

Evaluation of tinnitus in patients with Temporomandibular Disorders through Axis II of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and the Tinnitus Handicap Inventory (THI)

BACKGROUND

Tinnitus is a quite common and bothersome disorder that results in a perceived sound or noise, without an external origin, often causing notable psychological distress. Some interconnections between tinnitus, bodily pain perception, and psychological well-being were previously reported, thus the relationships between tinnitus and temporomandibular joint (TMJ)-related muscle issues, resulting in somatosensory tinnitus, must be deeply investigated. This study aims to assess the prevalence of tinnitus in patients with temporomandibular disorders (TMD) and to examine the correlation between tinnitus and scales assessing the severity of TMD as well as psychological-related parameters.

MATERIALS AND METHODS

In this cross-sectional study, a total of 37 adults with TMD symptoms were enrolled. Diagnostic data were collected using the Axis II of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and the Tinnitus Handicap Inventory (THI) questionnaire. Statistical analysis included descriptive assessments and significance was set at p < .05.

RESULTS

Individuals with tinnitus and TMD reported a significantly higher number of body pain areas, indicating a link between tinnitus and increased bodily pain perception. Tinnitus did not significantly impact TMJ-related functions. Significantly higher levels of psychological distress were observed in individuals with tinnitus, as evidenced by elevated scores in depression, generalised anxiety and somatic symptoms.

CONCLUSION

Tinnitus is a complex condition with significant effects on health and well-being, requiring an interdisciplinary approach for effective evaluation and care. The study provides deep insights into the prevalence of tinnitus in TMD patients, underscoring the need for comprehensive treatment strategies addressing both TMD and tinnitus.

Therapeutic challenges in temporomandibular disorders

Background and aims

This study aimed at evaluating the etiology and treatment challenges of temporomandibular disorders (TMDs).

Methods

160 subjects with TMDs, 38 males (23.8%) and 122 females (76.3%) were studied. A personalized coefficient was designated, which included the resolution of the main symptom, correction of secondary symptoms, patient collaboration (emotional parameter), treatment duration, and cost.

Results

The most frequent cause for consultation was muscle impairment (42.5%), or limitation of mouth opening, followed by joint impairment (23.1%). Muscle pain was noticed, particularly in the masseter (57.5%) and lateral pterygoid muscles (51.9%). Tooth pain or gingival retraction was frequently associated with tooth wear (48.1%) and dental abfraction (31.3%). Remote symptomatology was dominated by otologic symptomatology. Iatrogenic etiology was highest (69.4%), followed by untreated missing teeth (66.9%). Treatment options included muscle relaxation, occlusal balancing (equilibration), kinesitherapy, medication, and swallowing re-education. Most patients benefited from four to seven different types of therapy, which resulted in a higher cost and a longer and more uncomfortable treatment. The primary symptom was relieved in 82.3% of cases, with recurrence occurring in 15.7%.

Conclusion

The treatment of temporomandibular joint dysfunction is time-consuming, demanding, and intricate. Most patients required four to seven different types of therapy, which increased the expense, treatment duration, and suffering.

Analysis of the Use of Sample Size and Effect Size Calculations in a Temporomandibular Disorders Randomised Controlled Trial-Short Narrative Review

BACKGROUND/OBJECTIVES

Temporomandibular disorder (TMD) is the term used to describe a pathology (dysfunction and pain) in the masticatory muscles and temporomandibular joint (TMJ). There is an apparent upward trend in the publication of dental research and a need to continually improve the quality of research. Therefore, this study was conducted to analyse the use of sample size and effect size calculations in a TMD randomised controlled trial.

METHODS

The period was restricted to the full 5 years, i.e., papers published in 2019, 2020, 2021, 2022, and 2023. The filter article type-"Randomized Controlled Trial" was used. The studies were graded on a two-level scale: 0-1. In the case of 1, sample size (SS) and effect size (ES) were calculated.

RESULTS

In the entire study sample, SS was used in 58% of studies, while ES was used in 15% of studies.

CONCLUSIONS

Quality should improve as research increases. One factor that influences quality is the level of statistics. SS and ES calculations provide a basis for understanding the results obtained by the authors. Access to formulas, online calculators and software facilitates these analyses. High-quality trials provide a solid foundation for medical progress, fostering the development of personalized therapies that provide more precise and effective treatment and increase patients' chances of recovery. Improving the quality of TMD research, and medical research in general, helps to increase public confidence in medical advances and raises the standard of patient care.

Climate temperature and seasonal influences on the prevalence of temporomandibular disorders in South Korea

This study aimed to explore seasonal variations in temporomandibular disorder (TMD) prevalence in South Korea, utilizing nationwide population-based big data. Data corresponding to the Korean Standard Classification of Diseases code of K07.6, which identifies TMD, were extracted from the Health Insurance Review and Assessment Service online platform for the period from 2010 to 2022. Additionally, we integrated these data with climate temperature records from the Korean Meteorological Administration. We subsequently conducted a statistical analysis of TMD patient data on a monthly and seasonal basis over the past 13 years to assess prevalence. Over the past 13 years, the number of TMD patients in Korea has steadily increased. The prevalence of TMD rose from 0.48% (224,708 out of a total population of 50,515,666) in 2010 to 0.94% (482,241 out of a total population of 51,439,038) in 2022, marking a 1.96-fold increase. Among children under 10 years of age, no significant differences were observed in TMD prevalence between boys and girls. However, a distinct female predominance emerged after the age of 10, with an average female-to-male ratio of 1.51:1. The peak prevalence of TMD occurred in individuals in their 20 s, followed by adolescents in their late 10 s. The majority of TMD patients were concentrated in Seoul and Gyeonggi province, with metropolitan areas accounting for 50% of the total patient count. Seasonally, TMD patient numbers showed no significant increase in winter compared with spring or summer. The temperature difference, defined as the absolute difference between the highest and lowest temperatures for each month, showed a positive correlation with TMD patient counts. A greater temperature difference was associated with higher patient counts. The strongest correlation between temperature differences and TMD patient numbers was observed in winter (r = 0.480, p < 0.01), followed by summer (r = 0.443, p < 0.01), and spring (r = 0.366, p < 0.05). Temperature differences demonstrated a significantly stronger correlation with the increase in the number of TMD patients than absolute climate temperatures. This aspect should be a key consideration when examining seasonal trends in TMD prevalence in South Korea.

Jaws of knowledge: an analysis of temporomandibular joint insights in dental training-a quasi-experiment study

Objectives

To access the knowledge of undergraduate and postgraduate students of the dental college on basic anatomy, physiology, clinical examination, and pathology of the temporomandibular joint (TMJ).

Materials and Methods

A total of 610 undergraduate and postgraduate students of dental college, were included in this study. The questionnaire was pretested for validation and distributed online through Google forms.

Results

A pairwise comparison showed that the percentage of correct answers for interns significantly differed from that of IV Bachelor of Dental Surgery (P=0.050) and postgraduate students (P=0.048) (below average: up to 6 correct answers, good: 7-11 correct answers, excellent: 12 or more correct answers).

Conclusion

TMJ diseases are common in daily life but frequently go undiagnosed and untreated due to a lack of clinical expertise. This demonstrates the necessity of providing instructions that give students in-depth knowledge and abilities for TMJ issues in clinical practice.

Performance of key physical tests for temporomandibular disorder via telehealth: Establishing validity and reliability

BACKGROUND

During the COVID-19 pandemic, many individuals sought healthcare virtually. Physiotherapy is integral in managing temporomandibular disorders (TMDs); therefore, establishing how key physical tests can be appropriately adapted to telehealth is paramount.

OBJECTIVES

To establish the validity and reliability of telehealth (specifically videoconferencing) assessments against in-person assessments on a battery of TMD physical tests.

METHOD

A repeated-measures study design was undertaken. Thirty-six adult participants (19 healthy and 17 TMD) underwent concurrent temporomandibular joint (TMJ) physiological movement measurements via videoconferencing and in-person as per standard clinical practice. Inclusion criteria included the presence of central incisors and no significant comorbidities precluding a safe telehealth examination. Participants with TMD completed seven additional pain provocation physical tests.

RESULTS

Agreement between telehealth and in-person physiological movement measures was excellent (ICC >0.90, 95% CI: 0.53 to >0.99). Inter- and intra-rater reliability for telehealth measures indicated excellent reliability (ICC >0.97, 95% CI: 0.91 to >0.99). Exact agreement between telehealth and in-person for provocation tests ranged between 58.8% and 94.1%. Fourteen of the twenty-six individual measures produced substantial to near perfect agreement (PABAK = 0.65-0.88), seven produced moderate agreement (PABAK = 0.53), while five produced poor to fair agreement (PABAK = 0.18-0.29).

CONCLUSION

There is high level of agreement between telehealth and in-person measurements of TMJ physiological movement and pain provocation tests.

Comparison of ultrasonography-based masticatory muscle thickness between temporomandibular disorders bruxers and temporomandibular disorders non-bruxers

To compare masticatory muscle thickness in patients with temporomandibular disorders (TMDs) during rest and clenching, and by body position, using ultrasonography. This prospective study included 96 patients with TMD (67 females, 29 males; mean age: 40.41 ± 17.88 years): group 1, comprising 66 patients with TMD without bruxism (TMD_nonbruxer), and group 2, comprising 30 patients with concurrent TMD and bruxism (TMD_bruxer). In patients with TMD, bruxism was correlated with the presence of tinnitus, muscle stiffness, sleep problems, psychological stress, and restricted mouth opening. The masseter muscle significantly thickened during clenching (11.16 ± 3.03 mm vs 14.04 ± 3.47 mm, p < 0.001), whereas the temporalis muscle showed no significant increase in thickness from resting to clenching in an upright position (7.91 ± 1.98 vs 8.39 ± 2.08, p = 0.103). Similarly, during clenching in the supine position, the masseter muscle was significantly thicker compared with rest (11.24 ± 2.42 vs 13.49 ± 3.09, p < 0.001), but no significant difference was observed in temporal muscle thickness (8.21 ± 2.16 vs 8.43 ± 1.94, p = 0.464). In comparison between two groups, the average thickness of the masseter muscle was greater among TMD_bruxers than among TMD_nonbruxers in both the upright and supine positions (all p < 0.05). In the generalized lineal model, female sex (B = - 1.018, 95% confidence interval [CI] - 1.855 to - 0.181, p = 0.017) and bruxism (B = 0.868, 95% CI 0.567 to 1.169, p = 0.048) significantly predicted changes in masseter muscle thickness. Female sex (B = - 0.201, 95% CI - 0.299 to - 0.103, p = 0.011), increased age (B = - 0.003, 95% CI - 0.005 to 0.000, p = 0.038), and muscle stiffness (B = - 1.373, 95% CI - 2.369 to - 0.376, p = 0.007) were linked to decreased temporal muscle thickness. Comparing TMD nonbruxer and bruxer muscle thicknesses in upright and supine positions revealed significant increased thickness in the masseter muscle during clenching but not in the temporalis muscle. Masseter muscle thickness varied significantly by sex, body position, and resting/clenching, notably influenced by bruxism. These findings emphasize the relevance of these factors in clinical examinations of patients with TMD.

Platelet-Rich Plasma in the Management of Temporomandibular Joint Pain in Young Adults With Temporomandibular Disorder

BACKGROUND

Temporomandibular disorder (TMD) encompasses a range of conditions affecting the temporomandibular joint (TMJ) and associated structures, with TMJ pain being a prevalent symptom. Conventional management strategies have limitations, which require the exploration of innovative interventions. Platelet-rich plasma (PRP), known for its regenerative properties, presents a potential therapeutic avenue. This study aims to investigate the effectiveness of PRP in reducing the pain associated with mild TMJ in young adults.

METHODOLOGY

Participants (n = 128) aged 18 to 35 years with mild TMD were evenly randomized into PRP treatment and placebo control groups. PRP was prepared using a standardized protocol, and intra-articular injections were administered. Placebo injections mimic PRP. Follow-up evaluations were carried out at four and eight weeks after the intervention.

RESULTS

The study successfully randomized comparable groups, and the PRP treatment group experienced a significant reduction in TMJ pain (visual analog scale [VAS] score: 6.8 ± 1.2 to 2.1 ± 1.0 at eight weeks, P < 0.001). The PRP treatment also increased the largest opening of the mouth (from 38.2 ± 2.5 to 43.5 ± 3.1, P < 0.001) and the number of lateral movements (12.3 ± 1.5 to 14.9 ± 2.0, P < 0.001), while the placebo group had very few changes. Positive patient-reported outcomes on daily activities were observed, with no serious complications reported in either group.

CONCLUSIONS

This study provides evidence supporting the efficacy of PRP in reducing TMJ pain, improving jaw function, and improving quality of life in young adults with mild TMD. The results underscore the potential of PRP as a minimally invasive intervention for TMJ disorders.

Prevalence of temporomandibular disorders in clear aligner patients using orthodontic intermaxillary elastics assessed with diagnostic criteria for temporomandibular disorders (DC/TMD) axis II evaluation: A cross-sectional study

BACKGROUND

The objective of this investigation is to assess the relationship between the utilisation of orthodontic intermaxillary elastics and temporomandibular disorder (TMD) symptoms in clear aligner patients and to examine the correlation between the elastic usage time with the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD)-Axis II Evaluation Forms.

METHODS

This study was carried out on a total of 40 clear aligner patients using intermaxillary elastics in the experimental group and 30 clear aligner patients who did not use any intermaxillary elastics in the control group. The data were evaluated using the Mann-Whitney U, chi-square, Fisher's exact chi-square, and Fisher Freeman Halton exact chi-square tests.

RESULTS

The characteristic pain intensity, mastication, mobility, communication, global and PHQ-9 scores of the experimental group were significantly higher than those of the control group (p < .05). The characteristic pain intensity score, interference score and chronic pain grade score of patients using Class III elastics were statistically significantly higher than those of patients using Class II elastics (p < .05). Patients who used elastics for less than 6 months had statistically significantly higher PHQ-9 scores than those who used elastics for more than 6 months (p < .05).

CONCLUSIONS

Orthodontic treatment may affect occlusion, bite force and jaw movement, which may cause or worsen TMD symptoms, and the DC/TMD questionnaires can determine if orthodontic patients acquire TMD by assessing their psychosocial state and pain-related problems.

Specific tissue engineering for temporomandibular joint disc perforation

BACKGROUND

The temporomandibular joint (TMJ) disc is a critical fibrocartilaginous structure with limited regenerative capacity in the oral system. Perforation of the TMJ disc can lead to osteoarthritis and ankylosis of the TMJ because of the lack of disc protection. Clinical treatments for TMJ disc perforation, such as discectomy, hyaluronic acid injection, endoscopic surgery and high position arthroplasty of TMJ, are questionable with regard to long-term outcomes, and only three fourths of TMJ disc perforations are repairable by surgery, even in the short-term. Tissue engineering offers the potential for cure of repairable TMJ disc perforations and regeneration of unrepairable ones.

OBJECTIVES

This review discusses the classification of TMJ disc perforation and defines typical TMJ disc perforation. Advancements in the engineering-based repair of TMJ disc perforation by stem cell therapy, construction of a disc-like scaffold and functionalization by offering bioactive stimuli are also summarized in the review, and the barriers developing engineering technologies need to overcome to be popularized are discussed.

Effectiveness of Rehabilitation for Disk Displacement of the Temporomandibular Joint-A Cross-Sectional Study

(1) Background: Dislocations of articular disk can occur as a result of parafunctions in the Temporo Mandibular Joint (TMJ), which limits the opening of the mandible and other movements. The aim of this study was to evaluate the effectiveness of rehabilitation in patients with disk displacement of the TMJ. A total of 327 subjects with Temporo Mandibular Disorders underwent stomathognatic physiotherapy. (2) Methods: Based on the results obtained by a manual functional analysis, 35 patients who were identified with articular disk locking (disk displacement without reduction) were included in the study. The study group (N = 35) was subjected to passive repositioning of the articular disk, reposition splints, and physiotherapy. The patient's TMJs were then examined before the therapy, immediately after the therapy, and during the follow-up visit 3-6 weeks after the therapy. The Diagnostic Criteria for the Most Common Intra-articular Temporomandibular Disorders was used to evaluate the effects of rehabilitation on the patients' range of motions and the Numeric Pain Rating Scale (NPRS). For the statistical analysis, Pearson's r correlation coefficient test and Wilcoxon signed-rank test were used. (3) Results: The results showed a significant improvement in the range of motion of the mandible movements. The level of improvement was dependent on the time from the incident until undergoing rehabilitation. (4) Conclusions: The stomatognathic physiotherapy applied increased the range of motion of the mandible and reduced pain levels to the expected range.

Proprioceptive neuromuscular facilitation stretching exercises for treatment of temporomandibular dysfunction in patients with forward head posture: A double-blinded, randomized, controlled trial

BACKGROUND

Proprioceptive neuromuscular facilitation (PNF) stretching exercises have been widely advocated for the management of patients with different musculoskeletal conditions. However, its effect on the treatment of temporomandibular dysfunction (TMD) in patients with forward head posture (FHP) has not been fully investigated.

OBJECTIVE

To investigate the effect of PNF stretching exercises on the treatment of TMD in patients with FHP.

METHODS

A prospective, randomized, double-blinded clinical trial. Twenty-four patients with TMD and FHP aged from 18-40 years were randomly assigned to PNF or control group. The PNF group composed of 12 patients received PNF stretching exercises of masticatory muscles in addition to routine physical therapy treatment (FHP correction exercises and ultrasound for the temporomandibular joint); the control group composed of 12 patients received routine physical therapy treatment only. Interventions were conducted twice a week for six weeks. Craniovertebral angle, pain threshold, pain intensity, temporomandibular joint ROM, and temporomandibular joint function were assessed for all participants before and after the intervention. The outcomes were analyzed using Two-way mixed MANOVA. For further multiple comparisons, post-hoc tests with the Bonferroni correction were performed.

RESULTS

There was no significant difference between both groups pre-treatment (p> 0.05). Comparison between groups post-treatment revealed statistically significant differences in all outcome measures (p< 0.05) in favor of the PNF group.

CONCLUSION

Adding PNF stretching exercises of masticatory muscles to routine physical therapy programs is an effective method for management of TMD in patients with FHP more than routine physical therapy programs alone.

Efficacy of the transcutaneous electrostimulation in treatment dysfunctions of the TMJ associated with occlusion distortions

BACKGROUND

The study evaluation of the effectiveness the method of electrostimulation in treatment TMJ associated with occlusion disorders with the use of a patches by the company "Aganyan''.

METHODS

The study included 54 patients with temporomandibular dysfunction syndrome who had previously undergone endodontic dental treatment. In patients temporomandibular disorders (TMD) determined on the basis of Diagnostic criteria for temporomandibular disorders(DC/TMD).All patients had occlusion disorders due to errors after dental filling restoration. To diagnose the TMJ, a CT scan was used. The complex therapy also included therapy and with the use of a patches by the company "Aganyan''. The wearable patch includes a flexible substrate, a binder an adhesive layer, with an electrode foil attached to it. Patients applied one patch behind each TMJ. The patches were applied for eight hours every third day for three months. All the patients were given full-fledged endodontic treatment and restoration of the crown part, taking into account anatomical features.

RESULTS

The dynamics of the complex treatment of patients diagnosed with TMJ dysfunction syndrome showed that after treatment, the clinical symptoms gradually decreased and disappeared at the end of treatment. CT scan a year after treatment showed a normal ratio of TMJ elements. Сomplex treatment was effective in 87% of patients, after 3-5 months gradually decreased pain, noise in the joints, restriction of opening and closing of the mouth disappeared. Patients recovered their chewing functions, psycho-emotional state.

CONCLUSION

The results of the studies revealed a positive effects for the complex treatment dysfunctions syndrome TMJ the using the patches by the company "Aganyan" through electrical stimulation with low intensity.

Short-term heart rate variability at rest in individuals with temporomandibular disorder: a comparative analysis

OBJECTIVE

Compare heart rate variability (HRV) indices in participants with and without myogenic temporomandibular disorder (TMD). Secondarily, we correlated HRV indices with pain and quality of life variables.

METHODS

This is a comparative observational cross-sectional study. Individuals of both genders with and without a history of TMD were included. Short-term heart rate variability was assessed using a Polar V800. Central sensitization was assessed using the Central Sensitization Inventory. Pain through the numeric pain scale and the impact of oral health on quality of life using the OHIP-14 questionnaire.

RESULTS

A total of 80 participants were enrolled in the study: most individuals included in both groups were young adults, women and slightly overweight. We observed a decrease in HRV in the TMD group (p < 0.01) when compared to the control group. In addition, we observed a greater impact of oral health on quality of life, central sensitization in addition to high resting pain scores (p < 0.01). We observed significant correlation between the LF index of HRV and the FAI score (r = 0.311; p = 0.05). The NPS, CSI and OHIP-14 scores did not correlate with any of the HRV indices (p > 0.05).

CONCLUSION

The short-term HRV in individuals with TMD is significantly lower when compared to a control group. Furthermore, there seems to be a relationship between the severity of the dysfunction and the HRV variables.

CLINICAL RELEVANCE

Using portable and low-cost devices, the HRV can be easily collected and analyzed, without the need for an arsenal of equipment such as the conventional electrocardiogram. This measure can contribute to the therapy adopted and identify individuals prone to unfavorable outcomes involving ANS modulation.

Assessment of condylar anatomy and degenerative changes in temporomandibular joint disorders - A scoping review

Temporomandibular disorders (TMDs) are a group of conditions that cause pain and dysfunction in the temporomandibular joint (TMJ) and muscles that control mandibular movement. In most cases, the etiology is unclear and is considered multifactorial. Recent research suggests that some forms of TMD could be associated with specific TMJ morphological characteristics. This study aims to provide a review of the reported anatomical and degenerative morphological condylar characteristics of subjects with a clinical diagnosis of TMD as described with the use of CBCT imaging, as well as the detection of potential predisposing anatomical factors. This review was developed and reported in accordance with the PRISMA-ScR Checklist. A comprehensive search was performed in five databases. Reports were screened by two independent reviewers based on preselected inclusion and exclusion criteria. 45 studies were included in this review. The most frequently reported degenerative changes associated with TMD were condylar surface erosion, flattening, osteophytes, and sclerosis. Anatomical characteristics included a small condylar size and a posterior position of the condylar head in the TMJ. The anterosuperior area of the condylar head appears to be the most frequently affected. More studies are required to determine potential specific predisposing anatomical characteristics.

Therapeutic effects of kartogenin on temporomandibular joint injury by activating the TGF-β/SMAD pathway in rats

Patients with temporomandibular dysfunction (TMD) usually suffer from pathology or malpositioning of the temporomandibular joint (TMJ) disk, leading to the degenerative lesion of condyles. Kartogenin can promote the repair of damaged cartilage. This study aimed to explore whether intra-articular injection of kartogenin could alleviate the TMJ injury induced by type II collagenase. We measured the head withdrawal threshold and found that kartogenin alleviated the pain around TMD induced by type II collagenase. We observed the morphology of the condylar surface and found that kartogenin protected the integration of the condylar surface. We analyzed the density of the subchondral bone and found that kartogenin minimized the damage of TMJ injury to the subchondral bone. We next explored the histological changes and found that kartogenin increased the thickness of the proliferative layer and more collagen formation in the superficial layer. Then, to further ensure whether kartogenin promotes cell proliferation in the condyle, we performed immunohistochemistry of proliferating cell nuclear antigen (PCNA). The ratio of PCNA-positive cells was significantly increased in the kartogenin group. Next, immunofluorescence of TGF-β1 and SMAD3 was performed to reveal that kartogenin activated the TGF-β/SMAD pathway in the proliferative layer. In conclusion, kartogenin may have a therapeutic effect on TMJ injury by promoting cell proliferation in cartilage and subchondral bone. Kartogenin may be promising as an intra-articular injection agent to treat TMD.

Effects of a program consisting of strain/counterstrain technique, phonophoresis, heat therapy, and stretching in patients with temporomandibular joint dysfunction: A pilot study

BACKGROUND

The present study was conceptualized as a pilot study to examine the effects of a 3-week program consisting of strain/counterstrain technique (SCST), phonophoresis, heat therapy, and stretching exercises on pain and functions in patients with temporomandibular dysfunction (TMD).

METHODS

Seven participants (mean age 25.85 years) diagnosed with TMD having pain in the temporomandibular joint (TMJ) area with decreased jaw opening were recruited for the study. Treatment interventions consisting of SCST, phonophoresis (ultrasound gel mixed with diclofenac gel), heat therapy, and stretching (mouth-opening) exercises were performed 3 days a week for 3 weeks. SCST was performed on the masseter, medial, and lateral pterygoid muscles. No control group was present in the study.

RESULTS

Paired samples t test revealed a significant difference in numerical pain rating scale (NPRS) (decreased by 50%, P < .001) and jaw functional limitation scale (JFLS) (reduced by 59.58%, P < .001) scores after 3 weeks of intervention. A large effect size (Cohen d = -3.00 for NPRS and -3.16 for JFLS) was observed for both variables. No correlation (R = 0) was found between the baseline values of NPRS and JFLS.

CONCLUSION

A 3-week program consisting of SCST, phonophoresis, heat therapy, and stretching exercises was effective in reducing the pain and improving the functions related to TMJ in patients suffering from TMD. However, a randomized controlled trial is needed to reach a definite conclusion.

Impact of molar teeth distalization by clear aligners on temporomandibular joint: a three-dimensional study

BACKGROUND

Maxillary molar distalization is a common technique used in the non-extraction treatment of Angle Class II malocclusion that can effectively correct the molar relationship and create spaces for anterior teeth alignment. However, this approach may also impact the temporomandibular joint (TMJ) due to predictable changes in the posterior vertical dimension. Despite its widespread use, Class II malocclusions correction by molar distalization with clear aligners has not been investigated for their effects on the TMJ. Therefore, this study aimed to analyze the impact of sequential molar distalization using clear aligners on the TMJ.

METHODS

Three-dimensional CBCT scans of 23 non-growing patients (7 males, 16 females; mean age 29.8 ± 4.6 years) with skeletal class I or II malocclusion and a bilateral molar class II relationship treated by sequential upper molars distalization with orthodontic clear aligners (Invisalign, Align Technology, San Josè, Ca, USA). A total of 46 joints were examined before and after molar distalization using Anatomage InvivoDental 6.0.3. Linear and angular measurements of the mandibular joint were measured, including joint parameters, inclination, position, and the dimension of the condyle and articular fossa. In addition, 3D volumetric spaces of the joint were analyzed. All data were statistically analyzed by paired T test to determine the differences between the pre-and post-orthodontic procedures.

RESULTS

No statistically significant differences were found in all primary effects resulting from maxillary molars distalization by clear aligners on TMJ components measurements and joint spaces between T0 and T1. Meanwhile, statistically significant differences were observed in the linear position of the upper molars and the molar relationship parameter with at least P ≤ 0.05.

CONCLUSION

Treatment by sequential upper molars distalization with clear aligners does not lead to significant TMJ parameters changes in condyle and fossa spaces, dimensions, and positions.

Prevalence and severity of temporomandibular joint disorder in partially versus completely edentulous patients: A systematic review

Temporomandibular joint disorders (TMDs) following tooth loss may or may not be prevalent, but the risk of developing these disorders is always there due to changes in occlusion and vertical dimension, leading to changes in the disc-fossa relationship. The purpose of this systematic review was to evaluate the prevalence and severity of temporomandibular joint (TMJ) disorder in partially versus completely edentulous patients. An elaborated literature search was conducted in PubMed/Medline, Scopus, Web of Science, Lilacs, and Google Scholar databases including all articles about varied effects of partial and complete edentulism on the TMJ published from January 1, 2000, to January 1, 2022. After the meticulous screening, only publications which fulfilled the inclusion parameters were ultimately selected for full-text evaluation and tested for bias using the Joana Briggs Institute Appraisal tools for cross-sectional, case-control, and cohort studies. A total of 547 articles from various electronic databases and manual searches were found. After eliminating the duplicates and thorough screening, 13 studies were included for qualitative synthesis. Most of the studies demonstrated at least one or two signs of the presence of TMDs following tooth loss, the intensity/frequency of which increased in proportion to the number of missing teeth.

Degenerative Disorder of the Temporomandibular Joint Treated With Autologous Bone Marrow-Derived Stem Cells Using the Regentime Technique: A Case Report

Temporomandibular joint (TMJ) disease is a type of degenerative musculoskeletal disorder that leads to morphological and functional abnormalities. It has a poorly understood progression with numerous independent and interrelated factors, which makes it difficult for the available treatment options to meet long-term demands.  We present the case of a 37-year-old woman who suffered from excruciating pain in the right temporomandibular joint, associated with limited mandibular movement. She was found to have imaging features of TMJ disorder. She underwent the Regentime procedure which uses autologous bone marrow-derived stem cells that are partially differentiated and redirected to the targeted tissue. Clinical follow-up showed total clinical recovery.

Mesenchymal stem cells-derived microvesicles versus platelet-rich plasma in the treatment of monoiodoacetate-induced temporomandibular joint osteoarthritis in Albino rats

Temporomandibular joint osteoarthritis (TMJ-OA) is a serious disease, designated by severe joint pain and dysfunction. Limitations of current therapeutics have led to an increased interest in regenerative strategies. Recently, the non-surgical treatment of OA has seen increased use of biologic injectable therapies like mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP). Although these biotherapies represent an admirable effort, more studies are necessary to determine their efficacy. Thus, the aim of this study was to assess the curative potential of a single intra-articular injection of bone marrow MSCs-derived microvesicles (BM-MSCs-MVs) versus a single intra-articular injection of PRP in monoiodoacetate (MIA)-induced TMJ-OA model in Albino rats. Forty-eight male rats were used. A single intra-articular unilateral MIA injection was utilized to induce TMJ-OA. One week post induction, rats were sorted into 3 groups (16 rats each): group (I): received no treatment, groups (II) & (III): received BM-MSCs-MVs and PRP respectively. Scarification was done at 2 and 4 weeks from onset of treatment. Histological changes of the condylar TMJ were examined with H&E staining. Expression of IL-1β, TNF-α, NF-κB, MMP-13, MMP-3, and collagen ΙΙ markers was detected using real-time PCR. Histologically, the osteoarthritic group exhibited degenerated condylar tissues which were aggravated at 4 weeks. Oppositely, a marked improvement in the condylar TMJ histology was noticed in both the BM-MSCs-MVs-and PRP-treated groups at both time intervals. Additionally, the treated groups showed a decrease in IL-1β, TNF-α, NF-κB, MMP-13 and MMP-3 and an increase in collagen ΙΙ genes expression in contrast to the untreated group. Moreover, this difference was significant in the BM-MSCs-MVs group as compared to the PRP-treated group. Our results concluded that BM-MSCs-MVs as well as PRP treatments were able to target the key pathological features in OA, mainly inflammation and matrix degradation, and helped in restoring condylar structure in TMJ-OA rat model. However, BM-MSCs-MVs treatment exhibited more efficient therapeutic potential as compared to PRP treatment.

Effects of Contact Sports on Temporomandibular Disorders: An Observational Study

The study investigated the prevalence of temporomandibular disorders in 100 competitive athletes in contact sports, equally grouped by the practiced game: Soccer (SoG), Rugby (RG), American Football (AFG), Boxing (BoG), Basketball (BaG), compared to a randomly control group of 20 non-athletes (CG). Symptoms and signs were examined according to the standardized Diagnostic Criteria for Temporomandibular Disorders through a questionnaire and clinical evaluation. Arthralgia showed significant differences between RG and CG and between AFG and CG (p < 0.05). Study groups reported masticatory muscle pain during function, neck and shoulder pain more frequently than CG, except for BoG. Closing click was significantly more present in study groups than CG, while crepitation was significantly higher only in RG and AFG. The deviation was wider in SoG, RG and AFG compared to CG (p < 0.05). Tukey’s multiple comparisons test showed a statistically significant reduction in right laterotrusion in RG vs. CG (p < 0.05); the comparison showed a decrease in right laterotrusion in RG vs. SoG and BoG (p < 0.05), a decrease in endfeel in RG vs. CG, BaG and AFG (p < 0.05). The data seem to support a relationship between the prevalence of TMD symptoms and signs in competitive athletes in contact sports, especially in RG and AFG compared to CG.

sEMG and Vibration System Monitoring for Differential Diagnosis in Temporomandibular Joint Disorders

The stomatognathic system represents an important element of human physiology, constituting a part of the digestive, respiratory, and sensory systems. One of the signs of temporomandibular joint disorders (TMD) can be the formation of vibroacoustic and electromyographic (sEMG) phenomena. The aim of the study was to evaluate the effectiveness of temporomandibular joint rehabilitation in patients suffering from locking of the temporomandibular joint (TMJ) articular disc by analysis of vibrations, sEMG registration of masseter muscles, and hypertension of masticatory muscles. In this paper, a new system for the diagnosis of TMD during rehabilitation is proposed, based on the use of vibration and sEMG signals. The operation of the system was illustrated in a case study, a 27-year-old woman with articular dysfunction of the TMJ. The first results of TMD diagnostics using the k-nearest neighbors method are also presented on a group of fifteen people (ten women and five men). Vibroacoustic registration of temporomandibular joints, sEMG registration of masseter muscles, and functional manual analysis of the TMJ were simultaneously assessed before employing splint therapy with stomatognathic physiotherapy. Analysis of vibrations with the monitoring of sEMG in dysfunctions of the TMJ can lead to improve differential diagnosis and can be an objective way of monitoring the rehabilitation process of TMD.

The Impact of Wearing a Face Mask during the COVID-19 Pandemic on Temporomandibular Joint: A Radiological and Questionnaire Assessment

Aim  Several health problems have been reported to be triggered or facilitated by prolonged mask usage during the coronavirus disease 2019 (COVID-19) pandemic. While wearing a face mask, people tend to push their jaws forward and downward in a repetitive manner to hold their masks in the right position; these jaw motions may induce temporomandibular joint disorder (TMD). In this study, we aimed to investigate these repetitive jaw movements while wearing face masks and their effects on TMD. Patients and Methods  Patients who applied with TMD signs between June 2020 and May 2021 were evaluated prospectively. A survey using a questionnaire was conducted to define patients with TMD that caused only by mask-related repetitive jaw movements. Demographic data (age and gender), mean duration of daily mask usage, mask type, and magnetic resonance imaging results were recorded. Results  Prolonged daily mask usage (≥8 hours/day) was significantly higher in patients with mask-related habits (group a) with a rate of 40.4% ( p ≈ 0.001). Also, in this group, the disc displacement with reduction rate (54.6%) was higher compared with other groups ( p ≈ 0.010). On the contrary, patients with no underlying risk factor (group c) showed an unexpected high osteoarthritis rate ( p ≈ 0.029). Conclusions  In this study, we demonstrate that correcting the position of a face mask by repetitive jaw movements can increase the occurrence of TMD. Informing individuals wearing face masks about the risk of TMD and the importance of choosing the appropriate mask size according to the face shape are important issues to be addressed in the near future.

Depth-dependent patterns in shear modulus of temporomandibular joint cartilage correspond to tissue structure and anatomic location

To fully understand TMJ cartilage degeneration and appropriate repair mechanisms, it is critical to understand the native structure-mechanics relationships of TMJ cartilage and any local variation that may occur in the tissue. Here, we used confocal elastography and digital image correlation to measure the depth-dependent shear properties as well as the structural properties of TMJ cartilage at different anatomic locations on the condyle to identify depth-dependent changes in shear mechanics and structure. We found that samples at every anatomic location showed qualitatively similar shear modulus profiles as a function of depth. In every sample, four distinct zones of mechanical behavior were observed, with shear modulus values spanning 3-5 orders of magnitude across zones. However, quantitative characteristics of shear modulus profiles varied by anatomic location, particularly zone size and location, with the most significant variation in zonal width occurring in the fibrocartilage surface layer (zone 1). This anatomic variation suggests that different locations on the TMJ condyle may play unique mechanical roles in TMJ function. Furthermore, zones identified in the mechanical data corresponded on a sample-by-sample basis to zones identified in the structural data, indicating the known structural zones of TMJ cartilage may also play unique mechanical roles in TMJ function.

Temporomandibular disorder treatment algorithm for otolaryngologists

OBJECTIVE

To review current literature describing the management of temporomandibular disorder (TMD) and to propose an evidence-based algorithm for otolaryngologists.

DATA SOURCES

A literature review using PubMed and Scopus was conducted to identify manuscripts that describe TMJ disorder etiology, diagnostic methods, and management across the fields of otolaryngology, general practice medicine, physical therapy, dentistry, and maxillofacial surgery.

REVIEW METHODS

Two reviewers subjectively evaluated the studies based on the inclusion criteria, incorporating them into a comprehensive algorithm.

CONCLUSIONS

TMD is one of the most common conditions presenting to otolaryngology outpatient clinics. Etiologies of TMD vary widely, including myofascial, intraarticular, neurologic, traumatic, or psychiatric in origin. When conservative measures fail to produce symptom relief, alternative treatments and referral to outside specialists including psychiatry, physical therapy, dentistry, and maxillofacial surgery may be indicated. Premature or inappropriate referrals may lead to patients suffering TMD for extended periods of time, with alternating referrals between various specialists. Thus, we present a TMD treatment algorithm for otolaryngologists to aid in the decision-making process in managing TMD.

IMPLICATIONS FOR PRACTICE

Patients frequently present to otolaryngology outpatient clinics for symptoms of TMD. Multidisciplinary practice may be necessary to effectively treat TMD of varying etiology and severity. Following conservative treatment, appropriate referrals and treatment plans will reduce ineffective use of resources, deferral of treatment, and patient suffering. For this reason, a comprehensive algorithm for otolaryngologists will improve resource utilization and efficiency of treatment to ultimately provide improved treatment outcomes for patients.

The Relationship between Stress and Masticatory Muscle Activity in Female Students

The aim of the study was to analyze the relationship between stress measured by the perceived stress scale (PSS-10) questionnaire and masticatory muscle activity. Experimental design assumed the study of healthy young women without temporomandibular disorders, dividing them into three groups depending on the result of the stress level and then comparing these groups in terms of bioelectrical activity of the masticatory muscles. After the exclusion criteria were applied, 63 female students (mean age: 22.3 ± 2.4 years) from Medical University of Lublin were included in the study. The subjects were then divided into 3 groups: with low (n = 18), medium (n = 18) and high stress level (n = 27), according to PSS-10 results. Resting and functional activity of temporalis anterior (TA) and masseter (MM) muscles were measured by electromyograph BioEMG III. There were statistically significant effects of group on the absolute value of asymmetry index (AsI) of TA and MM during maximum voluntary clenching on dental cotton rollers (both p = 0.02). Post hoc analysis shows that there were statistically significant differences between medium and high stress groups in AsI TA (p = 0.01) and between low and high stress groups in AsI MM (p = 0.02). Perceived stress measured by PSS-10 questionnaire seems to be associated with changes in muscular asymmetry in functional clenching activity.

Association between Temporomandibular Joint Disorder and Parkinson's Disease

This study performed two different analyses using a large set of population data from the Korean National Health Insurance Service Health Screening Cohort to evaluate the interactional association between temporomandibular disorder (TMD) and Parkinson’s disease (PD). Two nested case–control population-based studies were conducted on 514,866 participants. In Study I, 4455 participants with TMD were matched with 17,820 control participants, with a ratio of 1:4. In Study II, 6076 participants with PD were matched with 24,304 control participants, with a ratio of 1:4. Obesity, smoking, alcohol consumption, systolic, diastolic blood pressure, fasting blood glucose level, and total cholesterol were adjusted. The adjusted odds ratio (OR) for TMD was 1.43 (95% confidence interval (CI) = 1.02–2.00) in PD patients compared to non-PD patients in Study I (p < 0.001). The adjusted OR for PD was 1.56 (95% CI = 1.13–2.15) in TMD patients compared to non-TMD patients in Study II (p = 0.007). This study demonstrated that patients with TMD have a significantly higher risk of developing PD and, conversely, those with PD have a significantly higher risk of developing TMD.

Otological manifestation of temporomandibular joint disorder in Ekiti, a sub-Saharan African country

OBJECTIVE

To determine the prevalence, sociodemographic features, and clinical presentation of temporomandibular joint disorder in otorhinolaryngological practice.

METHODS

This prospective hospital-based study involved patients diagnosed with temporomandibular joint disorder in our institution's ear, nose, and throat department. Data for this study were obtained from the patients using pretested interviewer-assisted questionnaires.

RESULTS

The prevalence of temporomandibular joint disorder in this study was 1.3%. The study population included 17 (26.2%) male patients with a male:female ratio of 1.0:2.8. Joint disorder accounted for 75.4% of all disorders, while both mastication muscle and joint disorder accounted for 21.5%. A majority of the patients (47.7%) presented between weeks 1 and 13 of the illness. Unilateral temporomandibular joint disorder accounted for 98.5% of all disorders. The main otologic clinical features were earache and a dull tympanic membrane in 100% and 35.4% of patients, respectively. Middle ear assessment revealed type A in 73.8% of patients and type B in 20.0% according to Jerger's classification system of tympanometry. Most patients (81.5%) were referred by their family physician. All patients had undergone prehospital treatment prior to presentation.

CONCLUSION

Temporomandibular joint disorder is a common presentation in medical practice. Common clinical features include ear, joint, and mastication muscle disorders.

Evaluation of temporomandibular disorders among dental students of Saudi Arabia using Diagnostic Criteria for Temporomandibular Disorders (DC/TMD): a cross-sectional study

BACKGROUND

Temporomandibular disorders (TMD) are a broad category of conditions arising from the various components of the temporomandibular joint complex. Bio-psychosocial model is the most accepted theory describing the etiopathogenesis of TMD. Dental students are vulnerable to psychological disorders, including anxiety, depression, and stress. Hence, the aim of the current study was to evaluate the prevalence and possible risk factors of TMD among dental students of various academic levels and explore the association of TMDs with demographic, academic, and psychosocial parameters.

METHODS

A total of 246 students of a Saudi Arabia dental school were chosen for the study. After getting consent, all students were examined according to the Diagnostic Criteria for Temporomandibular Disorders, including Axis I and II components.

RESULTS

The overall cross-sectional prevalence of TMD was found to be 36.99%. Pain arising from the jaw, temple, and the peri-auricular area were the most commonly reported symptoms and elicited signs during examination. Among the pain-related TMD, myalgia was the commonest diagnosed condition, whereas disc displacement with reduction was found prevalent in the intra-articular disorder category. Female (OR = 1.94; P = 0.004), married (OR = 1.74; P = 0.04), and students in clinical academic levels (OR = 1.65; P = 0.03) were found to have significantly increased risk of TMD. Among the psychosocial parameters, anxiety (OR = 1.55; P = 0.04) and parafunctional behaviours (OR = 2.10; P < 0.001) were shown to increase the risk of developing TMD. Students with any TMD reported to have significantly higher pain intensity levels (OR = 1.68; P = 0.01) and jaw functional limitations (OR = 1.45; P = 0.008).

CONCLUSION

Dental students, especially in clinical levels were shown to pose a higher risk of developing TMD, hence strategies such as academic counselling and objective evaluation via rubrics should be planned to modify the administration of the curriculum, training methods and evaluation process.

Fast and accurate protocol for histology and immunohistochemistry reactions in temporomandibular joint of rats

OBJECTIVE

Propose a standard, fast and accurate protocol for the processing of the temporomandibular joint (TMJ) of adults' rats for histology and immunohistochemistry reactions.

DESIGN

Wistar male rats were perfused with paraformaldehyde (4 %). The heads were fixed in formaldehyde 10 % solution for 48 h. After that, the heads were sectioned in a sagittal plane and fixed for plus 48 h. Decalcification was performed using 20 % formic acid for 96 h and delimitation of TMJ area was done. Detailed methodology to a standard extraction and processing of TMJ to histological sections is described. Different buffers, equipment, temperature and time were tested to optimize immunostaining. Morphological preservation and antigenicity were evaluated by hematoxylin and eosin staining and immunohistochemistry reaction.

RESULTS

The current findings demonstrated that TMJ fixed in 10 % formaldehyde and decalcified in 20 % formic acid optimized decalcification processing time with preservation of cell morphology. Antigen retrieval with citrate buffer in pressure cooker (2 min at 100 °C and 5 min at room temperature) demonstrated the best protocol to preservation of the structures of TMJ.

CONCLUSIONS

This work demonstrates in detail a methodology of a fast and accurate TMJ processing for histology and immunohistochemistry reactions that guarantee tissue integrity and quality of staining.

Temporomandibular joint imaging: current clinical applications, biochemical comparison with the intervertebral disc and knee meniscus, and opportunities for advancement

Temporomandibular disorders encompass multiple pathologies of the temporomandibular joint that manifest as middle/inner ear symptoms, headache, and/or localized TMJ symptoms. There is an important although somewhat limited role of imaging in the diagnostic evaluation of temporomandibular disorders. In this manuscript, we provide a comprehensive review of TMJ anatomy, outline potentially important features of TMJ disc ultrastructure and biochemistry in comparison with the intervertebral disc and knee meniscus, and provide imaging examples of the TMJ abnormalities currently evaluable with MRI and CT. In addition, we provide an overview of emerging and investigational TMJ imaging techniques in order to encourage further imaging research based on the biomechanical alterations of the TMJ disc.

The Application of Intra-Articulr Injections for Management of the Consequences of Disc Displacement without Reduction

The aim of the study was to make a comparative studies on the effectiveness of platelet rich plasma (PRP) and hyaluronic acid (HA) in intra-articular injections to the temporomandibular joints-in double blind studies application-based on the analysis of selected clinical parameters of functional efficiency and the mean value of joint's pain intensity before and after management. The study enrolled a group of 100 patients, aged 21 to 43 years, of both sexes, who came for the prosthodontic treatment. All patients had II b group of disorder according to the Research Diagnostic Criteria/Temporomandibular Disorder, and were consecutively, alternately assigned to the groups, 50 patients in each. Study group PRP was treated with intra-articular injection of platelet rich plasma and study group HA had injection with hyaluronic acid. The examination was double-blind, so that the injecting physician and the patient were not informed what kind of medicinal substance they received in the joint injection. The final selected clinical parameters did not differ statistically significantly between the groups, what means that both administered substances were effective in the repair of intra-articular structures. The results of research showed that the use of PRP and HA in intraarticular joint's injections positively affects in selected clinical parameters and decrease of the pain in temporomandibular joints in the case of disc displacement without reduction.

Ultrasonography-guided arthrocentesis versus conventional arthrocentesis in treating internal derangement of temporomandibular joint: a systematic review

OBJECTIVES

This systematic review assessed the clinical question: 'Does ultrasonography (USG)-guided arthrocentesis provide better outcomes than conventional arthrocentesis in patients with temporomandibular disorder (TMD)?'

MATERIALS AND METHODS

The review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. An initial search was performed on electronic databases-including Medline, PubMed, and Cochrane Library-followed by manual and reference searches until the date September 27, 2019. The articles selected were evaluated for study and patient characteristics, arthrocentesis procedure details, and treatment outcomes (post-operative pain, maximum mouth opening (MMO), procedure time, and attempts of needle positioning). Risk of bias was assessed with the Cochrane Consumers and Communication Review Group's data extraction template and Critical Appraisal Skills Programme (CASP).

RESULTS

Out of the 325 initially identified articles, four studies with 144 patients were included in the final qualitative analysis. No significant differences were found in pain reduction and improved MMO between sample groups receiving conventional arthrocentesis and USG-guided arthrocentesis. Needle positioning attempts and procedural times were conflicting between the two groups.

CONCLUSIONS

This systematic review found that the outcomes of USG-guided arthrocentesis were not superior to conventional arthrocentesis. Conflicting data was found in the attempts of needle positioning and procedural time. Standardized treatment protocols and data from well-designed USG-guided arthrocentesis randomized clinical trials were lacking.

CLINICAL RELEVANCE

Arthrocentesis with or without USG guidance are both effective for treating patients with TMD to reduce pain and to improve MMO. USG-guided arthrocentesis was not found to be superior to conventional arthrocentesis.

Association between oxidative stress and temporomandibular joint dysfunction: A narrative review

BACKGROUND

The role of oxidative stress in temporomandibular disorders (TMDs) has been studied using synovial fluid, to evaluate oxidative stress (im)balance and its potential role in the onset and/or progression of the disease.

OBJECTIVE

This review aimed to evaluate the association between oxidative stress markers and the etiopathogenesis of TMJ dysfunction by means of synovial fluid analysis.

METHODS

Two independent reviewers searched the electronic databases from inception to March 2019: PubMed/MEDLINE, LILACS, SciELO, EMBASE, TRIPDATABASE, SCOPUS, and Google Scholar. The following key search terms were used: Temporomandibular Joint Disorders OR Temporomandibular Joint Disc OR Temporomandibular Joint Dysfunction Syndrome OR Temporomandibular Joint OR Facial Pain AND Free Radicals OR Oxidative Stress. Data were extracted from the selected articles, including study design, sample profile, TMJ disease reported, diagnostic method, reactive oxygen and nitrogen species evaluated, enzymatic and non-enzymatic antioxidants evaluated, and techniques used to measure free radicals and antioxidants.

RESULTS

After title and abstract screening of 6974 results, and full-text reading, 19 studies were included. All selected articles were cross-sectional observational studies. Enzymatic and non-enzymatic antioxidant defences appeared to be reduced in these patients, resulting in the establishment of the oxidative stress process. In addition, the studies showed a positive correlation between the severity of the intra-articular TMD and the increase in oxidative damage.

CONCLUSION

The establishment of oxidative stress, whether by an increase in reactive oxygen/nitrogen species or by a decrease in antioxidant defences, or a combination of both, may be associated with the establishment and maintenance of intra-articular damage.

Psychological Factors that Influence Decision-Making Regarding Trauma-Related Pain in Adolescents with Temporomandibular Disorder

We evaluated the clinical, magnetic resonance imaging (MRI), and psychological characteristics of adolescents with temporomandibular disorder (TMD) and compared facial macrotrauma effects between young and older adolescents. This case–control study included 70 randomly selected patients (35 young adolescents aged 12–16 years and 35 older adolescents aged 17–19 years) who had been diagnosed with TMD. Each age group was further subdivided according to the presence (T1) or absence (T0) of a macrotrauma history. All patients completed questionnaires on temporomandibular joint (TMJ) pain and dysfunction. We analyzed TMD severity symptoms using TMD-related indexes and the physical changes of TMJ using TMJ MR images. The Symptom Checklist-90-Revised was used to evaluate the patients’ psychological status. Anterior disc displacement was the most frequently observed MRI finding, occurring in a significant proportion of young (47 joints, 67.1%) and older adolescents (40 joints, 57.1%). The prevalence of all the MRI findings (disc displacement, disc deformity, condylar degeneration, and effusion) did not differ between the T0 and T1 subgroups among young and older adolescents. Conversely, the psychological factors differed significantly between the subgroups. Among young adolescents, the mean scores of somatization, obsessive-compulsiveness, hostility, phobic ideation, and psychosis were significantly higher in the T1 subgroup than in the T0 subgroup (all p < 0.05). Furthermore, these increased psychological scores positively correlated with TMD indexes. Clinicians should consider that a weakened psychological status could be an aggravating factor in young adolescents with TMD and should consider the implications in future assessment of such patients.

Impact of Temporomandibular Joint Complaints on Tinnitus-Related Distress

There is increasing evidence of associations between the presence of temporomandibular joint (TMJ) disorders and tinnitus. It has been recently proposed that tinnitus patients with TMJ complaints could constitute a subtype, meaning a subgroup of tinnitus patients responsive to specific treatments. Tinnitus patients with TMJ complaints are often young women with somatosensory features of their tinnitus. Here, we investigate the socio-economic factors, phenotypic characteristics and psychological variables of tinnitus subjects from the Swedish Tinnitus Outreach Project, with (n = 486) or without (n = 1,996) TMJ complaints. The prevalence of TMJ complaints was greater in tinnitus subjects with severe tinnitus (36%) when compared to those with any tinnitus (19%), strongly indicating the contribution of TMJ problems to the severity of tinnitus. Comparing subgroups with or without TMJ complaints in the whole sample, differences were found regarding a large number of socioeconomic, phenotypic, and psychological characteristics. Subjects with TMJ complaints were more often women, more often reported stress as the cause of tinnitus, were more severely affected by tinnitus, scored worse in measures of psychological well-being and life quality, and were more often affected by problems tolerating sounds, headache, vertigo/dizziness, and neck pain. In addition, they more often reported pulsating and tonal tinnitus, somatic modulation of tinnitus, and aggravation of tinnitus by loud sounds and stress. When focusing the analysis in subjects with tinnitus as a big problem using the Tinnitus Functional Index cut-off ≥ 48, or with severe tinnitus according to the Tinnitus Handicap Inventory cut-off ≥ 58, the impact of somatosensory modulations and stress on tinnitus were greater in subjects with TMJ complaints in comparison to those without. In light of these results, we hypothesize that stress could contribute to the co-occurrence of TMJ problems and tinnitus and also to the development of severe tinnitus. Our study supports the need of involving dental care and stress management in the holistic treatment of patients with severe tinnitus.

Síndrome da disfunção da articulação temporomandibular e o estresse presente no trabalho policial: revisão integrativa

Resumo O estudo objetivou investigar se o estresse presente nas atividades dos trabalhadores da polícia brasileira pode ter relação com o desenvolvimento da síndrome da disfunção da articulação temporomandibular (DTM), uma doença comumente associada a condições estressantes. Realizou-se uma revisão integrativa de literatura sobre os temas estresse, DTM e atividade policial. Foram identificadas diversas fontes estressoras no trabalho do policial brasileiro e observou-se que o estresse influencia no desenvolvimento, agravamento e tratamento dos sintomas da síndrome. Há comprometimento na qualidade de vida e saúde dos portadores de DTM. O fato de estudos terem mostrado associação entre estresse e atividades desenvolvidas pelos policiais brasileiros, bem como relação entre estresse e DTM, levou à suposição de que é possível haver relação entre o estresse gerado pelo trabalho executado por policiais e o risco de desenvolvimento da DTM por essa classe de trabalhadores. É recomendado que o indivíduo portador da síndrome seja avaliado como um todo antes da execução do tratamento e que esse tratamento seja multidisciplinar. A literatura sobre DTM em policiais ainda é incipiente, motivo pelo qual sugere-se o desenvolvimento de estudos sobre o tema.

Condylar dysfunctional remodeling and recortication: a case-control study

BACKGROUND

Temporo-mandibular disorders (TMD) is a collective term comprehending different clinical issues involving masticatory muscles, temporo-mandibular joint (TMJ) and other associated structures. TMD diagnosis is not made for its pathogenesis or etiology, but mainly on clinical symptoms. Primary dysfunction develops mostly on four factors: individual predisposition, high psychomotor activity (due to stress or parafunction), occlusal instability and low or absent tissue adaptation capability. On the other hand, secondary disorders can be caused by hereditary or congenital diseases, rheumatic inflammatory diseases, autoimmune and tumoral diseases. During their function, the condyles undergo a structural adaptive and physiological remodeling, but when mechanical stress exceeds adaptive capability, dysfunctional remodeling phenomena may occur. It is characterized by significant condylar morphological modifications at the level of the head of the condyle (smaller condyle), break of cortical integrity and reduced mandibular ramus height with subsequent mandibular retrusion and articular function alteration. The aim of this study is to compare condylar recortication amount, and pain reduction after two different therapeutic protocols.

METHODS

This is a case-control study. Twenty TMD patients were chosen and each of them underwent a documentation protocol including extraoral and intraoral photographs, dental casts, casts mounting on the articulator to evaluate CPI (CO-CR discrepancy index) and cone beam computed tomography (CBCT) of the mandibular condyles taken in closed mouth position. For the radiographic evaluation, a Planmeca ProMax 3D Mid system was utilized with an acquiring volume of 80×80 mm dimension, exposition 90 kV, 10.0 mA, 12 seconds with a DAP (Dose Area Product) of 1094 mGy·cm2 for each condyle. The acquired volume was elaborated by the Planmeca Romexis software v. 3.2.0.R and TMJ module. Seven coronal cuts and 10 sagittal cuts were performed on the head of the condyle to highlight the amount of cortication, before and after the application of two different therapeutic protocols. Protocol number 1 (N.=10 patients) included the exclusive use of a splint, while protocol number 2 (N.=10 patients) included the use of a splint associated with pharmacological therapy (NSAIDs, antioxidant, omega 3). The revaluation was performed on asymptomatic patient after a period of 6-8 months. The pain for each patient was assessed by a Visual Analogue Scale (VAS) from 0 to 10, 0 meaning no pain and 10 the worst pain ever felt. The VAS was evaluated after 10 days from the beginning of the treatment, after 3 months and after 8 months at the end of the treatment. Statistical analyses were carried using a χ2 test (P value <0.05).

RESULTS

No significant differences in the amount of cortication were found in the radiographic revaluation between the two different therapeutic protocols, even though it was noticed that the use of medicaments brought to a resolution of the symptoms in a shorter period of time (P=0.00001 after 10 days; P=0.0251 after 3 months).

CONCLUSIONS

According to this study, pharmacological protocol in the therapy of TMD does not seem to affect condylar cortication. Medicaments although seem to accelerate the disappearance of clinic symptomatology, but more researches are needed to valid these findings.

Advancements in temporomandibular joint total joint replacements (TMJR)

The goal of this paper is to review the advantages and disadvantages of the various treatment options of temporomandibular joint (TMJ) total joint replacement (TJR). TMJ articles published within the last 20 years were reviewed to collect the information on non-invasive and invasive TMD treatment methods. Recent technological advancements helped the evolution of treatment methods and offered significant value to TMD patients and surgeons. Considering the TMD levels, the therapeutic procedures can involve general health examiniations, physical therapy, medication, oral rehabilation or as an end stage clinical invention, temporomandibular joint replacement. In fact when intra-articular TMD is present, the effective treatment method appears to be TJR. However, concern for infection, material hypersensitivity, device longevity and screws loosening issues still exists. Further combined research utilizing the knowledge and expertise of, surgeons, material scientists, and bioengineers is needed for the development of improved TMD therapeutic treatment.

Temporomandibular Disorder: An Important Cause of Temporal Headache in Patients Unlikely to Have Giant Cell Arteritis

INTRODUCTION

Temporal headache often results in an Ophthalmology referral to rule out giant cell arteritis (GCA). When clinical suspicion of GCA is low, alternative diagnoses should be considered. Temporomandibular disorder (TMD) commonly causes a temporal headache.

MATERIALS AND METHODS

Patients referred with a temporal headache attending the Friday emergency ophthalmology clinic from February to July 2017 were assessed for GCA using the American College of Rheumatology (ACR) diagnostic criteria and TMD using a validated screening questionnaire.

RESULTS

Ten symptomatic patients presented and were screened for TMD during this period. Four had mild TMD, two moderate, and three severe. The mean TMD score in patients with less than 3 ACR GCA criteria was 14.75 (SD 4.03) versus 6.8 (SD 3.06) in patients with 3 or more criteria (p = 0.0075).

CONCLUSION

TMD is an important cause of a temporal headache in patients unlikely to have GCA. Onward referral to dentistry for further management may be merited.

Tissue Engineering for the Temporomandibular Joint

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.

Ultrasonographic evaluation of masseter muscle thickness in patients with disk displacement with reduction

OBJECTIVES

This study was performed to ultrasonographically assess the masseter muscle thicknesses of individuals with disk displacement with reduction.

METHODS

The thickness of the masseter muscle in 100 patients (28 male, 72 female; average age 34 years) who presented with one-sided temporomandibular joint pain and a clicking sound and were diagnosed with disk displacement with reduction was measured in relaxation and at maximum contraction using ultrasonography.

RESULTS

In the contracted position, the difference in the masseter muscle thickness between the healthy side and the side with disk displacement with reduction was statistically significant (p < 0.05). However, no statistically significant difference was found between the two sides in the relaxed position.

CONCLUSIONS

Obvious ultrasonographic changes of the masseter muscle were found in patients with temporomandibular disk displacement with reduction, and these changes might be related to unilateral chewing. Individuals with anterior disc displacement probably chew unilaterally because of pain and clicking.

Salivary Oxidant/Antioxidant Status in Chronic Temporomandibular Disorders Is Dependent on Source and Intensity of Pain - A Pilot Study

Temporomandibular disorders (TMD) have been associated with altered salivary oxidative status, but the relation with pain source and pain severity isn't clarified. With the aim to assess their interaction with TMD, we compared levels of selected salivary oxidative stress (OS) markers (glutathione peroxidase, superoxide dismutase, total antioxidant capacity (TAC), uric acid, 8-hydroxydeoxyguanosine, malondialdehyde) and salivary cortisol (SC) as a stress indicator, between 20 TMD patients and 15 healthy control subjects. In order to record differences relating to pain source and severity, patients were respectively classified according to specific diagnoses (myofascial pain or disc displacement (DD)), and pain intensity (high or low). TAC was significantly higher in TMD patients than in controls (morning p = 0.015; afternoon p = 0.005). Significant differences were also observed when TAC levels between high-intensity pain patients and controls were compared, as well as between DD patients and controls. In logistic regression analysis, higher levels of TAC were related to DD (morning OR: 1.66, 95%CI: 1.05-2.64, p = 0.029; afternoon OR: 2.10, 95%CI: 1.11-3.98, p = 0.021) and to high-intensity pain (morning OR: 1.81, 95%CI: 1.04-3.15, p = 0.037; afternoon OR: 1.79, 95%CI: 1.02-3.14, p = 0.043). We also found that morning SC was positively correlated with antioxidant parameters in TMD patients. Our data suggest compensatory mechanism as response to higher level of stress. This stress could be extrinsic and lead toward TMD, or intrinsic, emerging from established TMD, or could be both. The intensity and the source of pain should be considered important factors in future investigations evaluating salivary OS markers in TMD patients.

TMD symptoms and vertical mandibular symmetry in young adult orthodontic patients in North Sumatra, Indonesia: a cross-sectional study

Background: Temporomandibular joint disorder (TMD) includes symptoms of pain and dysfunction in the muscles of mastication and the temporomandibular joint. Differences in vertical condylar height, observed in the assessment of mandibular asymmetry, is a structural alteration that represents a risk factor for TMD. The study aimed to evaluate the association between TMD symptoms and vertical mandibular symmetry in young adult orthodontic patients in North Sumatra, Indonesia.  Methods: The cross-sectional study included 18-25-year-old (mean ± SD, 21.9 ± 2.0 years) old orthodontic patients admitted to the Dental Hospital of Universitas Sumatera Utara, Medan, between June 2016 and March 2017. Vertical mandibular asymmetry was assessed from all 106 subjects using Kjellberg's technique from pre-treatment panoramic radiographs. The TMD symptoms were assessed by structural interviews using modified questionnaires based on Temporomandibular Disorder Diagnostic Index and Fonseca's Anamnestic Index. Results: Of the 106 subjects, 26 (24.5% of the total) with vertical mandibular symmetry and 39 (36.8%) with vertical mandibular asymmetry were positive for TMD symptoms. By contrast, 17 patients (16.0% of the total) with vertical condylar symmetry and 24 patients (22.6%) with vertical mandibular asymmetry were regarded negative for TMD symptoms. There was no significant difference (p=0.520) in TMD symptoms based on vertical mandibular symmetry. Conclusion: The results from this studied Sumatran population indicate that there are common TMD symptoms in young adult orthodontic patients, but there is no significant association between vertical mandibular asymmetry and TMD symptoms. Further study on the development of TMD, mandibular asymmetry and treatment planning for growing patients is suggested, using longitudinal and transitional approaches.