Epidemiological analysis on 2375 patients with TMJ disorders: basic statistical aspects

Data analysis for differentiating temporo mandibular disorders (TMD) pain from tooth pain

The factors differentiating temporomandibular disorders (TMD) pain from tooth pain is of interest to dentists. Prior to receiving therapy, participants answered the six-question TMD Pain Screener questionnaire. Applying validated Diagnostic Guidelines for TMD (DC/TMD), an orofacial pain specialist and endodontic resident with board certification performed endodontic and TMD examinations. In our study, sensitivity was higher for TMD screener regarding identification of all types of TMDs (0.94 (0.80-0.97), TMD pain not referring to teeth (0.94 (0.76-0.98), TMD pain referring to teeth only (0.94 (0.64-1.00)). TMD Pain Screener questionnaire can be applied in identification of TMDS in patient seeking endodontic therapy.

Neurobiology of bruxism: The impact of stress (Review)

Bruxism is a non-functional involuntary muscle activity that affects more than one-third of the population at some point in their lives. A number of factors have been found to be related to the etiopathogenesis of bruxism; therefore, the condition is considered multifactorial. The most commonly accepted factor is stress. Stress has long been considered to increase muscle tone and to reduce the pain threshold. Current evidence indicates that exposure to chronic stress, distress and allostatic load ignite neurological degeneration and the attenuation of critical neuronal pathways that are highly implicated in the orofacial involuntary muscle activity. The present review discusses the negative effects that chronic stress exerts on certain parts of the central nervous system and the mechanisms through which these changes are involved in the etiopathogenesis of bruxism. The extent of these morphological and functional changes on nerves and neuronal tracts provides valuable insight into the obstacles that need to be overcome in order to achieve successful treatment. Additionally, particular emphasis is given on the effects of bruxism on the central nervous system, particularly the activation of the hypothalamic-pituitary-adrenal axis, as this subsequently induces an increase in circulating corticosterone levels, also evidenced by increased levels of salivary cortisol, thereby transforming bruxism into a self-reinforcing loop.

Platelet-rich plasma injections for the treatment of temporomandibular joint disorders: A systematic review

OBJECTIVE

This systematic review aimed to investigate and examine whether intra-articular injections of platelet-rich plasma (PRP) after arthrocentesis are beneficial for the treatment of temporomandibular disorders, when compared to other treatments, such as injections of hyaluronic acid (HA) or saline after arthrocentesis.

METHODS

An electronic search on PubMed was performed using combinations of the terms 'temporomandibular' and 'platelet rich plasma', to identify studies reported in English and published up until 2017. The initial screening identified 222 records, of which only seven fulfilled the inclusion criteria and were included in this review. Of these studies, three compared injection of PRP after arthrocentesis with the injection of HA after arthrocentesis, while two compared injection of PRP after arthrocentesis with Ringer's lactate after arthrocentesis and one compared injection of PRP after arthrocentesis to sodium chloride.

RESULTS

Five of the studies found that PRP injections have led to significant improvements in mandibular range of motion and pain intensity up to 12 months after treatment, while the remaining two studies found similar results for the different treatments.

CONCLUSION

However, a standardized protocol for PRP preparation and application needs to be established.

Is Irritable Bowel Syndrome Considered in Clinical Trials on Physical Therapy Applied to Patients with Temporo-Mandibular Disorders? A Scoping Review

The aim of the current scoping review was to identify if the presence of irritable bowel syndrome was included as eligibility criteria of participants included in clinical trials investigating the effects of physical therapy in individuals with temporomandibular pain disorders (TMDs). A systematic electronic literature search in the Web of Science database was conducted. Scientifically relevant, randomized clinical trials (those cited in other studies at least 5 times, or clinical trials published in high-impact journals, i.e., first and second quartiles (Q1-Q2) of any category of the Journal Citation Report (JCR)) evaluating the effects of any physical therapy intervention in patients with TMDs were included. The Physiotherapy Evidence Database (PEDro) scale was used to evaluate the methodological quality of the selected trials. Authors affiliated to a clinical or non-clinical institution, total number of citations, objective, sex/gender, age, and eligibility criteria in each article were extracted and analyzed independently by two authors. From a total of 98 identified articles, 12 and 19 clinical trials were included according to the journal citation criterion or JCR criterion, respectively. After removing duplicates, a total of 23 trials were included. The PEDro score ranged from 4 to 8 (mean: 6.26, SD: 1.48). Based on the eligibility criteria of the trials systematically reviewed, none considered the presence of comorbid irritable bowel syndrome in patients with TMDs. The comorbidity between TMDs and irritable bowel syndrome is not considered within the eligibility criteria of participants in highly cited clinical trials, or published in a high-impact journal, investigating the effects of physical therapy in TMDs.

Identification of Biomechanical Properties of Temporomandibular Discs

Material

Experimental and model tests were conducted on ten fresh porcine temporomandibular joint discs. The average thickness of disc tissue was, accordingly, 2.77 mm for the anterior zone, 3.98 mm for the posterior, and 1.54 mm for the intermediate. The selection of research material in the form of porcine discs was due to the similarity to human discs.

Methods

Discs were loaded in cycles, a temporary course with the amplitude 3 N and frequency 0.07 Hz, and growth in the load was 1 N/s. The selection of load frequency was due to real conditions of temporomandibular joint functioning during mastication. The necessary experimental research was conducted on a testing machine with a measurement range of 2.5 kN.

Results

The obtained numeric calculation results indicate that the number of load cycles has a decisive impact on the limitation of energy dispersion capacity through disc tissue. This phenomenon was observed in all the studies on the disc areas. Along with the growth in load cycles, discs are stiffened, and the most significant stiffness was observed in the intermediate area.

Conclusions

Based on the conducted research, it should be concluded that excessive load affecting temporomandibular joints caused by the act of mastication and occlusal forces generated during parafunction and in people with defined long-term bruxism has crucial importance on biomechanical disc properties and hence the course of temporomandibular joint conditions.

Increased Risk of Temporomandibular Joint Disorder in Patients with Rheumatoid Arthritis: A Longitudinal Follow-Up Study

We evaluated the incidence of temporomandibular disorder (TMD) in patients with rheumatoid arthritis (RA) and examined the association between TMD and RA, through longitudinal follow-up. Population data from the Korean National Health Insurance Service-Health Screening Cohort from 2002 to 2015 was used. From 514,866 subjects, 3122 with RA were matched with 12,488 controls in a 1:4 ratio. The crude and adjusted models (for obesity, smoking, alcohol consumption, blood pressure, blood glucose, total cholesterol, and Charlson Comorbidity Index scores) were calculated. Chi-square tests, Kaplan-Meier (KM) analysis, and two-tailed analyses were used for statistical analysis. Stratified Cox proportional hazard models were used to assess the hazard ratios (HR) and 95% confidence intervals (CI) for TMD in the RA group, compared to those in the control group. The adjusted HR for TMD in RA was 2.52 (95% CI = 1.70–3.74), compared to the control group. The results were consistent with the subgroup analyses, according to age and sex, except in men older than 60 years of age. KM analysis showed similar results. Hence, we found that patients with RA have a higher risk of TMD, and should be observed for symptoms of the initial stage of TMD to prevent the risk of aggravation.

The role of the styloid apophysis of the temporal bone in the biomechanics of the tongue, mandible, hyoid system: a case study

Temporomandibular disorders are characterized by ear pain, tinnitus, difficulty in chewing, dysphagia and dizziness, cervical limitation of range of movement (ROM) and other less common disorders. Numerous recent studies associate the presence of these signs and symptoms with an elongated styloid apophysis, as in the case of Eagle syndrome. The purpose of this clinical case is to support the thesis of a common syndrome that temporomandibular joint (TMJ) disorders with an elongated styloid process affirming the relationship between temporal bone, mandible, hyoid bone and tongue. The patient was a 57-year-old woman who reported having ear algia and tinnitus all on the right side with difficulty chewing accompanied by odynophagia and dysphagia of solid and liquid foods, as well as cervical disorders. Computed tomography (CT) scans of the neck showed elongation and ossification of the styloid processes of the temporal bone. Magnetic resonance imaging (MRI) showed an anterior right dislocation of the TMJ articular disc. The patient presented classic symptoms of temporomandibular disorders, with the primary examinations showing an anterior right dislocation of the articular disc of the TMJ, as well as a longer styloid process on the same side. We therefore suggested that, in this case report, TMJ disorders might be associated with a longer styloid process on the same side.

Assessment of condylar morphology and position using MSCT in an Asian population

OBJECTIVES

The purpose of the present study was to investigate the volume, surface, morphometric index (MI), and position of the condyle in a normal population by applying Mimics 17.0 software. Then, the difference between left and right sides, sex, and age can be explored, which will contribute to establish the reference value of condylar morphology and position in normal individuals, and help us to study characteristics of condylar morphology and position in abnormal individuals.

MATERIALS AND METHODS

Three-hundred subjects were enrolled in our study from the radiology department of Shanghai Jiao Tong University Affiliated Sixth People's Hospital. They were divided into three groups according to the age: group 1 (18-24 years old), group 2 (25-34 years old), and group 3 (35-44 years old). Each group included 100 subjects (with 50 males and 50 females). They were examined using multislice computed tomography (MSCT) after that. All images of condyle were reconstructed by Mimics 17.0 software, so as to measure the volume, surface, and MI of condyle, and to analyze the position of condyle in the articular fossa by means of joint spaces.

RESULTS

The differences of condylar volume, surface, and MI between left and right sides were not obvious (P > 0.05). The condylar volume and surface were greater in males than females (P < 0.05), while their condylar MI existed no difference (P > 0.05). No statistical differences were found in volume and surface among three age groups. However, the MI of group 1 was statistically lower than that of group 3 (P < 0.05). On the other hand, no significant differences were found between left and right condylar position (P > 0.05). Nevertheless, there were significant differences of condylar position regarding the gender and age (P < 0.05).

CONCLUSIONS

This study showed no significant differences in condylar morphology and position between left and right sides, but factors of gender and age were proven to have a certain influence on the morphology and position of the condyle. This information can be clinically useful in establishing the diagnostic criteria for condylar morphology and position in the normal Asian population.

CLINICAL RELEVANCE

Examination of condylar morphology and position is important for evaluating the abnormalities and bony changes that affect the temporomandibular joint (TMJ). So, this will be conducive to the diagnosis and the evaluation of therapeutic effect of temporomandibular joint diseases. Also, it is important to evaluate these indexes prior to commencing orthodontic treatment, because TMJ abnormalities play a critical role in orthodontic treatment planning.

Temporomandibular Disorders and Headache: A Retrospective Analysis of 1198 Patients

Aim. Headache is one of the most common diseases associated with Temporomandibular Disorders (TMDs). The aim of this study was to evaluate, retrospectively, if headache influences TMD's symptoms. Material and Methods. A total sample of 1198 consecutive TMD patients was selected. After a neurological examination, a diagnosis of headache, according to the latest edition of the International Classification of Headache Disorders, was performed in 625 subjects. Patients were divided into two groups based on presence/absence of headache: Group with Headache (GwH) and Group without Headache (GwoH). Descriptive statistics and Chi-square index were performed. Results. Sociodemographic (gender, marital status, and occupation) and functional factors, occlusion (occlusal and skeletal classes, dental formula, and occlusal abnormalities), and familiar pain did not show a statistically significant correlation in either group. Intensity and frequency of neck pain, arthralgia of TMJ, and myalgia showed higher correlation values in GwH. Conclusion. This study is consistent with previous literature in showing a close relationship between headache and TMD. All data underlines that headache makes pain parameters more intense and frequent. Therefore, an early and multidisciplinary treatment of TMDs should be performed in order to avoid the overlay of painful events that could result in pain chronicity.

Splint-assisted disc plication surgery

Chronic disc displacement may lead to long-term pain. Temporomandibular joint surgery is reserved for those patients whose symptoms remain severe despite conservative treatment. We looked at the of effect of modified meniscopexy on patients with chronic disc displacement without reduction who did not respond to non-surgical pain management treatment. In this retrospective study a total of 59 joints was treated and all patients except one underwent splint assisted bilateral meniscopexy: this patient had splint assisted unilateral meniscopexy. At the time of presentation and following treatment all patients underwent clinical examination and were required to complete a pain and functional questionnaire. All patients reported improvement following treatment.

The "at-home LLLT" in temporo-mandibular disorders pain control: a pilot study

OBJECTIVES

The Temporo-Mandibular Disorders (TMD) are a set of dysfunctional patterns concerning the temporo-mandibular joints (TMJ) and the masticatory muscles; its main symptom is pain, probably caused by inflammatory changes in the synovial membrane, alterations in the bone marrow of the mandibular condyle and impingement and compression. The aim of this preliminary study was to investigate the effectiveness in the TMD pain reduction of a new laser device recently proposed by the commerce that, due to its reduced dimensions and to be a class I laser according the ANSI classification, may be used at home by the patient himself.

MATERIAL AND METHODS

Twenty-four patients with TMD were randomly selected: the inclusion criteria for the sample was the diagnosis of mono- or bi-lateral TMD, with acute pain restricted to the joint area, associated with the absence of any muscle tenderness during palpation. The patients were randomly assigned to two groups: Group 1 (12 patients): patients receiving real LLLT (experimental group). Group 2 (12 patients): patients receiving inactive laser (placebo group). The treatment was performed once a day for two weeks with an 808 nm diode laser by the patient himself with irradiation of the cutaneous zone corresponding to the TMJ for 15 minutes each side. Each patient was instructed to express its pain in a visual analogue scale (VAS) making a perpendicular line between the two extremes representing the felt pain level. Statistical analysis was realized with GraphPad Instat Software, where P<0.05 was considered significant and P<0.01 very significant.

RESULTS

The patient's pain evaluation was expressed in the two study groups before the treatment, 1 week and two weeks after the treatment. The differences between the two groups result extremely significant with p<0.0001 for the comparison of VAS value after 1 and 2 weeks.

CONCLUSION

This study, even if it may be considered such a pilot study, investigated a new way to control the pain in the temporo-mandibular diseases by an at home self administered laser device. RESULTS are encouraging but they will have to be confirmed by greater studies.

Psychosocial aspects of bruxism: the most paramount factor influencing teeth grinding

In clinical practice, patients suffering from an occlusal parafunctional activity have increased. It can be observed that a negative influence of environment aggravates patient's health. The aim of this paper is to present the impact of environment and development of human civilization on the prevalence of bruxism and the correlation between them. The authors grasp the most relevant aspects of psychological and anthropological factors changing over time as well as their interactions and describe a relationship between chronic stress and bruxism. Current literature shows how contemporary lifestyle, working environment, diet, and habits influence the patient's psychoemotional situation and the way these factors affect the occluso-muscle condition.

Prevalence and correlation between TMD based on RDC/TMD diagnoses, oral parafunctions and psychoemotional stress in Polish university students

The aim of the study was to assess the prevalence of temporomandibular disorders (TMD) and oral parafunctions, as well as their correlation with psychoemotional factors in Polish university students. The research was conducted in a group of 456 students (N = 456). The examination form comprised of two parts: survey and clinical examination. The research diagnostic criteria for temporomandibular disorders (RDC/TMD) was used in order to assess TMD. Symptoms of TMD were observed in 246 (54%) students after clinical examination. The largest group involved students with disc displacement (women: 132, 29%; men: 70, 15%). Women (164; 36%) suffered more frequently than men (82; 18%) from problems related to the stomatognathic system (P < 0.05), described themselves as easily excitable and emotionally burdened, and reported symptoms as tightness of the facial and neck muscles (P < 0.05). In 289 (64%) students intraoral symptoms concerning occlusal parafunctions were observed. In 404 (89%) examined students, nonocclusal parafunctions were recorded. A significant correlation between TMD and psychoemotional problems could be detected. TMD symptoms more often concern women. Emotional burden and excitability are factors predisposing muscular disorders.

Comparison of selected kinematic facebows applied to mandibular tracing

The study focused on the comparison between mechanical and computerized registration methods used by the two selected kinematic facebows. The material consisted of 35 women aged 18 to 35, studied using the Gerber Dynamic Facebow and the computerized ARCUSdigma II axiograph. To compare the devices the condylar path inclination (CPI) was recorded according to the Camper's line, enabling the acquisition of easily comparable values based on which the devices were objectively and subjectively analyzed. Statistics was performed for the obtained data. The study showed that the values for the CPI registrated by the ARCUSdigma II are significantly higher than those obtained by using the Gerber Dynamic Facebow. The significant difference in the records of the CPI is most likely a result of the differences in the registration techniques assumptions. ARCUSdigma II provides the user with more diagnostic options than Gerber Dynamic Facebow. Mechanical facebow handling has a higher risk of hand-measuring errors in tracing procedure. Due to high discrepancy of achieved results from different systems the authors recommend to use articulator compatible with facebow whose measurement has been done.