Temporomandibular disorders and mandibular vertical asymmetry

Objective To analyze the association between mandibular vertical asymmetry and the presence of TMD in adult patients.

Methods This case-control study recruited patients from the orthodontic clinic at FEBUAP. Patients were classified on the basis of diagnostic criteria for temporomandibular disorders (DC/TMD). Panoramic radiographs were measured to determine mandibular vertical asymmetry indices according to criteria described by Kjellberg and Habets. Both methods (DC/TMD and index criteria) were standardized a priori.

Results A total of 56 patients were analyzed, of whom 25 (44.6%) met the inclusion criteria and were divided into two groups (TMD group, n = 15; non-TMD group, n = 10). The highest asymmetry index was observed in the condylar neck, followed by the total condylar asymmetry index, but without significant differences between groups (p > .05).

Conclusion There is no association (p > .05) between temporomandibular disorders and mandibular vertical asymmetry.     

Kinematic analysis of mandibular motion before and after orthognathic surgery for skeletal Class III malocclusion: A pilot study

Objectives: The aim of the study was to detect the changes in 3D mandibular motion after orthognathic surgery for skeletal Class III malocclusion.

Method: Using a 3D motion analyzer, free mandibular border movements were recorded in nine patients successfully treated for skeletal Class III malocclusion and in nine patients scheduled for orthognathic surgery. Data were compared using Mann–Whitney non-parametric U-test.

Results: The results showed no differences between the groups in the total amount of mouth opening, protrusion, and in lateral excursions, but the percentage of mandibular movement explained by condylar translation was significantly increased after surgery (20% vs. 23.6%). During opening, the post-surgery patients showed a more symmetrical mandibular interincisal point and condylar path than pre-surgery patients (p < 0.01).

Discussion: Patients treated with orthognathic surgery for skeletal Class III malocclusion recover a good and symmetric temporomandibular joint function.     

A comparative clinical study of temporomandibular disorder patients in the otolaryngology clinic versus a rheumatology clinic

Objective Temporomandibular disorders (TMD) may be associated with local or widespread symptoms, including pain. The aim of this study was to compare clinical features of TMD patients presenting to an otolaryngology clinic with TMD patients presenting to a rheumatology clinic.

Methods The study included 107 patients in the otolaryngology setting and 103 patients in the rheumatology setting. A comparison between both groups was made regarding the clinical data.

Results Patients in the otolaryngology setting featured more otological symptoms, compared with those in the rheumatology setting. Otological symptoms were affirmed in 70 patients (65.4%) in the otolaryngology setting but in only 18 patients (17.5%) in the rheumatology setting (p = 0.001). Patients in the rheumatology setting showed more structural TMJ changes, compared with those in the otolaryngology setting (p < 0.01).

Conclusion Patients presenting to the otolaryngologist may clinically and pathologically represent a different cohort from those presenting to the rheumatologist.     

Immunohistochemical expression of TLR-4 in temporomandibular joint dysfunction

Objective Toll-like receptor 4 (TLR-4) is a transmembrane protein involved in the innate immune system and has been implicated in the pathogenesis of temporomandibular joint dysfunction (TMD). The purpose of this study was to histologically examine the level of expression of TLR-4 relative to severity of TMD.

Methods Thirty-one human TMJ disc samples were immunostained for TLR-4 and evaluated for intensity of stain. Among the samples, 8 were control samples, 16 were from patients with anterior disc displacement with reduction (ADDwR), and 7 were from patients with anterior disc displacement without reduction (ADDwoR).

Results There was no statistically significant difference in intensity of stain between groupings (p = 0.673).

Conclusions The results indicate a negative correlation between TMD and the expression of TLR-4.     

Impact of pain-related temporomandibular disorders on jaw functional limitation,psychological distress and quality of life in postoperative class III East Asian patients

Objectives

This cross-sectional study determined the prevalence of painful TMD and its impact on jaw function, psychological status and oral health-related quality of life (OHRQoL) in postoperative Chinese patients. It also assessed factors influencing OHRQoL of these patients.

Materials and methods

Subjects were recruited from the National Dental Centre Singapore dentofacial deformity registry. Invitations to participate in the study were sent to patients who sought treatment from March 2011 to November 2017. Patients who consented were directed to an online link to complete a series of questionnaires based on the Diagnostic Criteria for TMD (DC-TMD) and the orthognathic quality of life questionnaire (OQLQ).

Results

The subjects (n = 99) had a mean age of 25.2 ± 6.0 years and postoperative time of 29.4 ± 22.7 months. 18.2% were found to suffer from pain-related TMD postorthognathic surgery and these patients (n = 18) had significantly higher median JFLS-8 score than those without TMD pain (p = 0.008). Time since surgery was significantly associated with OHRQoL (p = 0.00000026).

Conclusions

Prevalence of painful TMD and psychological distress was low while prevalence of jaw functional limitation was moderately high in postoperative class III Chinese patients.

Clinical relevance

Painful TMD impacted jaw function especially when subjects open wide enough to drink, yawn, talk and smile but had no significant consequence on psychological status and OHRQoL.

     

The effect of orthognathic surgery on temporomandibular disorder

This study aimed to evaluate the difference in prevalence of temporomandibular disorder (TMD) before and after orthognathic surgery (OGS), particularly in patients with mandibular asymmetry.A prospective cohort study of patients undergoing corrective orthognathic surgery was conducted. Pre-operative and post-operative (3 months, 6 months and 1 year) TMD assessment were performed according to the Diagnostic Criteria for TMD (DC/TMD) protocol.64 patients were included in the study. Overall, there was a significant reduction of 26.5% in TMD prevalence from 60.9% pre-operatively to 34.4% 1-year post-operatively (p = 0.003). In all, 37.5% of patients had their TMD condition treated, 50% had no change in their symptoms while 12.5% experienced a worsening of their symptoms. No significant difference in terms of change in TMJ status was observed among the different ramus procedures, the type and magnitude of mandibular movement, skeletal class, and presence of mandibular asymmetry.In conclusion, it appears that corrective orthognathic surgery for dentofacial deformities might provide a secondary benefit of treating TMD. However, surgeons have to be aware that a small percentage of patients might experience a deterioration of their TMD condition, and that those who were previously asymptomatic may develop TMD symptoms after surgery.     

Reliability of mandibular movement assessments depending on TMD

Objective: This study determines the effect of temporomandibular disorders (TMD) on the reliability of mandibular movement assessments.

Methods: The vertical and horizontal jaw movements, as well as overjet and overbite, were measured twice in 56 consecutively recruited adult subjects with TMD according to the RDC/TMD and 29 controls without TMD diagnosis by experienced dentists utilizing a millimeter ruler. The reliability was determined by intraclass correlation coefficient (ICC).

Results: Neither statistically nor clinically relevant differences in the repeatability between both subgroups could be detected (all p ≥ 0.077). The mouth opening and overjet proved an excellent reliability (ICC 0.85–0.92). Overbite and laterotrusion showed good to excellent reliable results (ICC 0.74–0.82). The second measurement of the vertical jaw movement resulted in systematically higher values (p < 0.003).

Discussion: The assessment of the mandibular movement with a millimeter ruler is a reliable procedure irrespective of TMD. To decrease the variances in the mouth opening measurements, the patient should be asked beforehand to practice this movement.     

The potential etiologic factors influencing tinnitus intensity in patients with temporomandibular disorders

Objectives: To investigate the potential relationships between the intensity of tinnitus associated with temporomandibular disorders (TMD) and potential etiologic factors, including age, gender, freeway space, sleep bruxism (SB), joint clicking, and headache.

Methods: The sample was comprised of 90 patients without any hearing loss, as confirmed by otorhinolaryngology, who self-reported subjective tinnitus and simultaneous TMD, based on the Research Diagnostic Criteria for TMD (RDC/TMD).

Results: The results showed a positive, weak correlation between the intensity of tinnitus and age (r = 0.225, p = 0.033). The presence of SB and headache were seen in higher proportions in the present sample, at 75.5% (n = 68) and 66.6% (n = 60), respectively.

Conclusions: In a population of patients with subjective tinnitus and TMD, no significant associations were found between tinnitus intensity and age, freeway space, SB, clicking presence, and headache, though gender did show a weak correlation with tinnitus intensity.     

Prevalence of temporomandibular joint disorder among North Saudi University students

The aim of the current investigation was to study the prevalence of temporomandibular disorder (TMD) among university students of North Saudi Arabia.

Methods:A specifically constructed questionnaire was distributed to 489 university students to investigate the prevalence of temporomandibular joint (TMJ) findings among them. The study sample consisted of 346 males and 143 females (age range was 18–25?years). The data were analyzed, and probability values were set at p?≤?0.05.

Results:A total of 49.7% of participants had at least one sign or symptom of TMD. Clicking was the most reported finding. Pain in or about the ears/cheeks was the second most common finding. In all, 24.3% of the participants reported one TMJ finding; meanwhile, 0.4% reported the presence of five concurrent TMJ signs and symptoms. Females reported more TMJ signs and symptoms than males (p?p?Discussion:University students in north Saudi Arabia reported high prevalence of TMD. Also, students from science and health colleges reported higher prevalence of TMD findings than humanitarian college students. Clicking and pain are the most prevalent findings of TMD among university students. The results of this investigation highlight the need for additional research to shed more light on the risk factors and findings related to TMD. This will facilitate drawing adequate guidelines for prevention and management of TMD.     

Temporomandibular clinical exploration in Italian adolescents

Objective: This study investigated the prevalence of the signs and symptoms of temporomandibular disorders (TMD) among Italian adolescents.

Methods: The data were recorded from 567 subjects (246 males and 321 females; age range 11–19 years), grouped according to age and molar class relationship.

Results: Forty-four point one percent of subjects showed at least one sign or symptom of TMD, which were significantly more frequent in the 16–19 year-old group (52.9%) in respect to the 11–15 year-old group (39.8%) (χ ² = 8.78; p = 0.003). Signs and/or symptoms were about 1.6 times more frequent in subjects with Class II/1 malocclusion (χ ² = 13.3, p = 0.0003), mostly for TMJ sounds (χ ² = 1.444; p = 0.036). Myalgia was more frequent in females than in males (χ ² = 3.882; p = 0.049).

Conclusion: TMD signs and/or symptoms among Italian adolescents seem diffused (44.1%). Therefore, all adolescents should be screened thorough medical history and clinical examination.     

Longitudinal study on TMJ disk status and its effect on mandibular growth

Abstract

Objective: This longitudinal study assessed the potential contribution of temporomandibular joint (TMJ) disk status over mandibular linear and angular changes.

Design: Cohort study.

Setting: Edmonton, Alberta, Canada.

Participants: Seventy-three adolescent subjects attending TMJ or orthodontic clinics with or without TMJ disk abnormality were followed during a mean 3 years 7 months. From this sample 39 subjects underwent orthodontic treatment.

Methods: Disk displacement and disk length measurements taken from MRIs were utilized to evaluate the TMJ disk status. Mandibular changes were quantified from cephalometric radiographs by superimposing the mandible around the internal cortex of the posterior wall of the mandibular symphysis. Fishman’s skeletal maturation system was used to calculate the percentage of mandibular growth remaining during the follow-up. This expected mandibular growth was factored out through a statistical normalization process applied to the actual difference between the initial and final mandibular measurements. In addition, previous orthodontic treatment was also considered for the analysis. A multiple analysis of variance (MANOVA) was used to evaluate interaction between the independent variables (TMJ disk status and previous orthodontic treatment) over the dependent variables (mandibular ramus, mandibular body, mandibular length and gonial angle measurements).

Results: No significant contribution was found of any of the evaluated variables or its interactions over the mandibular measurements.

Conclusions: No evidence was found of TMJ disk abnormality as an associated significant factor with mandibular dimensional changes. The findings have to be evaluated with caution because of some limitations identified in this study.     

Anamnestic Index Severity and Signs and Symptoms of TMD

Abstract

The aim of this study was to determine the frequency and to characterize the symptoms and clinical signs of temporomandibular disorders (TMD) related to each severity category of Fonseca’s anamnestic index in a sample of Brazilian young adults (mean age 21.61±1.91 years, 87% females and 13% males), by the application of an anamnestic index proposed by Fonseca (1992) and by clinical examination considering mandibular range of motion and tenderness to palpation of stomatognathic system structures. A significant number of participants were classified with mild TMD (43.2%) and moderate TMD (34.8%). Pain frequency during mastication, temporomandibular joint (TMJ) pain, and TMJ sounds were shown to be good predictors of TMD severity. Neck pain, headache, difficulty during mouth opening and lateral deviation, and tenderness to palpation of masticatory sites and during protrusion accompanied the TMD severity but failed to demonstrate differences between moderate and severe groups, showing a poor ability to determine TMD severity progression. This study suggests that not only the frequency of signs and symptoms of TMD should be determined, but also symptom severity and its relationship to the presence of clinical signs in order to discriminate patients with real treatment needs in nonpatient samples.     

ASSESSMENT OF TEMPOROMANDIBULAR DISORDER AND OCCLUSION IN TREATED CLASS III MALOCCLUSION PATIENTS

Objective:

The aims of this study were to compare the prevalence of temporomandibular disorders (TMD) in individuals submitted to either orthodontic or ortho-surgical Class III malocclusion treatment and to assess the influence of occlusal aspects on TMD severity.

Material and methods:

The sample consisted of 50 individuals divided into two groups, according to the type of treatment (orthodontic or orthodontic with orthognathic surgery). The presence of signs and symptoms of TMD was evaluated by an anamnestic questionnaire and a clinical examination, including TMJ and muscle palpation, active mandibular range of motion, joint noises and occlusal examination.

Results:

Based on the anamnestic questionnaire, 48% had no TMD, 42% had mild TMD and 10% had moderate TMD. The presence and severity of TMD did not show any relationship with the type of orthodontic treatment (p>0.05). The chi-square test showed a positive association (p<0.05) between TMD and non-working side occlusal interferences.

Conclusion:

Based on the methodology used and the results obtained, it may be concluded that Class III orthodontic treatment was not associated with the presence of TMD signs and symptoms and the non-working side contacts can be occlusal factors of risk. There was no significant difference in TMD prevalence between the studied groups (orthodontically treated patients and patients treated with orthodontics followed by orthognathic surgery).     

Progressive condylar resorption after mandibular advancement

Progressive condylar resorption is an irreversible complication and a factor in the development of late skeletal relapse after orthognathic surgery. We have evaluated cephalometric characteristics, signs and symptoms in the temporomandibular joint (TMJ), and surgical factors in six patients (one man and five women) who developed it after orthognathic surgery. The findings in preoperative cephalograms indicated that the patients had clockwise rotation of the mandible and retrognathism because of a small SNB angle, a wide mandibular plane angle, and a "minus" value for inclination of the ramus. There were erosions or deformities of the condyles, or both, on three-dimensional computed tomography (CT) taken before treatment. The mean (SD) anterior movement of the mandible at operation was 12.1 (3.9)mm and the mean relapse was -6.4 (2.5)mm. The mean change in posterior facial height was 4.5 (2.1)mm at operation and the mean relapse was -5.3 (1.8)mm. Two patients had click, or pain, or both, preoperatively. The click disappeared in one patient postoperatively, but one of the patients who had been symptom-free developed crepitus postoperatively. In the classified resorption pattern, posterior-superior bone loss was seen in three cases, anterior-superior bone loss in two, and superior bone loss in one. Progressive condylar resorption after orthognathic surgery is multifactorial, and some of the risk factors are inter-related. Patients with clockwise rotation of the mandible and retrognathism in preoperative cephalograms; erosion, or deformity of the condyle, or both, on preoperative CT; and wide mandibular advancement and counterclockwise rotation of the mandibular proximal segment at operation, seemed to be at risk. The mandible should therefore be advanced only when the condyles are stable on radiographs, and careful attention should be paid to postoperative mechanical loading on the TMJ in high-risk patients.     

Temporomandibular dysfunction post-craniotomy: Evaluation between pre- and post-operative status

ObjectiveTo identify risk factors associated with post-operative temporomandibular joint dysfunction after craniotomy.MethodsThe study sample included 24 patients, mean age of 37.3 ± 10 years; eligible for surgery for refractory epilepsy, evaluated according to RDC/TMD before and after surgery. The primary predictor was the time after the surgery. The primary outcome variable was maximal mouth opening. Other outcome variables were: disc displacement, bruxism, TMJ sound, TMJ pain, and pain associated to mandibular movements. Data analyses were performed using bivariate and multiple regression methods.ResultsThe maximal mouth opening was significantly reduced after surgery in all patients (p = 0.03). In the multiple regression model, time of evaluation and pre-operative bruxism were significantly (p < .05) associated with an increased risk for TMD post-surgery.ConclusionA significant correlation between surgery follow-up time and maximal opening mouth was found. Pre-operative bruxism was associated with increased risk for temporomandibular joint dysfunction after craniotomy.     

Personality traits are potentially associated with the presence of chronic temporomandibular joint pain in patients without effusion as determined by T-2 weighted magnetic resonance

Objective: The study aimed at investigating personality traits in chronic temporomandibular joints (TMJ) pain patients with and without joint effusion.

Methods: Two groups of chronic TMJ pain patients were recruited. The TMJ pain control group was composed of patients showing magnetic resonance imaging (MRI) signs of TMJ effusion, while the TMJ pain test group included patients with chronic TMJ pain seemingly not justified, due to the absence of MRI-detected disorders. A third set of pain free individuals was selected as a comparison group. All patients completed a personality assessment with the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) instrument, and the between-group differences were assessed for significance by performing an analysis of variance test.

Results: Patients of the TMJ pain test group had higher scores than subjects belonging to the TMJ pain and pain-free control groups in almost all of the MMPI-2 clinical scales. A significant difference was shown for the scales related to concerns about physical health (Scale 1-Hs; F = 7.74; p = .001) and physical symptoms (Scale 3-Hy; F = 8.43; p = .001).

Conclusions: Chronic TMJ pain patients without MRI-detected TMJ effusion have a different personality profile than patients with TMJ effusion and pain-free individuals, regarding high levels of concerns about physical health and physical symptoms.

Clinical implications: This study has important clinical implications for temporomandibular disorders practitioners, providing suggestions that symptoms in the TMJ area are not only related to a physical disorder. The possible existence of a psychologically modulated condition in patients who refer pain in the TMJ area without signs of effusion should be carefully taken into consideration.     

Frequency of temporomandibular disorder signs and symptoms among call center employees

Objective: The current study aimed to investigate the frequency of signs and symptoms of temporomandibular disorders (TMD) among call center employees.

Methods: Workers from four call centers (CC) were invited to participate in this study. The examination was based on the Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD). The tenderness of the masticator muscles was assessed on both sides by bilateral palpation. The mobility of the mandible was measured with a plastic millimeter ruler on opening, lateral excursions, and protrusion.

Results: In total, 124 call center employees with a mean age of 28.61 ± 4.71 (between 22 and 47 years of age) were enrolled in this study. There was no statistically significant relation between the numbers of calls answered in a day and teeth clenching, teeth grinding, earache, tinnitus, or pain on yawning/chewing. Only protrusive movement pain and joint noise were significantly higher among employees who answered more than 140 calls/day (p < 0.01). An evaluation of the TMD signs and symptoms in relation to job stress level revealed that job stress level significantly affected the incidence of headaches among call center employees (p < 0.01).

Conclusion: The present study demonstrated no statistically significant relation between TMD signs and symptoms and call center employees except protrusive movement pain and joint noise. This relation was seen only in the employees who answered more than 140 calls per day. Headache, teeth clenching, and TMJ noise were the signs and symptoms encountered most often in this study. Multicentered studies in different geographic locations should be conducted to eliminate the limitation of this study.     

Sex differences in pharyngeal airway morphology in adults with skeletal Class III malocclusion

Objectives: To compare the pharyngeal airway dimensions in adults with skeletal Class III malocclusion and well-balanced faces, to ascertain whether sex can influence such measurements and to correlate skeletal pattern with pharyngeal dimensions.

Methodology: Fifty adults were recruited and assigned to two groups: skeletal Class III (n = 25; 12 males and 13 females, mean age = 26.1 years), and skeletal Class I (n = 25; 11 males and 14 females, mean age = 26.0 years), with well-balanced faces. Pharyngeal measurements were made using cone beam computed tomography and analyzed with Dolphin Imaging software 11.5.

Results: Pharyngeal sagittal area, length, retroglossal area and width were statistically greater for males. Pharyngeal volume was greater for Class III patients (p = .0245), due to enlarged male dimensions. A significant but moderate correlation was observed between pharyngeal airway volume and ANB angle (r = ?.4917) and effective mandibular length (Co-Gn, r = .5181).

Conclusion: There is sexual differentiation in the pharyngeal airway morphology for Class III adults. As females present similar pharynx volume compared to a normal skeletal pattern, mandibular setback surgery should be carefully planned because of the risk of airway constriction.