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Disc Displacement (disc + displacement)
Kinds of Disc Displacement Selected AbstractsThree-dimensional finite-element model of the human temporomandibular joint disc during prolonged clenchingEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2006Miho Hirose In the temporomandibular joint (TMJ), overloading induced by prolonged clenching appears to be important in the cascade of events leading to disc displacement. In this study, the effect of disc displacement on joint stresses during prolonged clenching was studied. For this purpose, finite-element models of the TMJ, with and without disc displacement, were used. Muscle forces were used as a loading condition for stress analysis during a time-period of 10 min. The TMJ disc and connective tissue were characterized as a linear viscoelastic material. In the asymptomatic model, large stresses were found in the central and lateral part of the disc through clenching. In the retrodiscal tissue, stress relaxation occurred during the first 2 min of clenching. In the symptomatic model, large stresses were observed in the posterior part of the disc and in the retrodiscal tissue, and the stress level was kept constant through clenching. This indicates that during prolonged clenching the disc functions well in the asymptomatic joint, meanwhile the retrodiscal tissue in the symptomatic joint is subject to excessive stress. As this structure is less suitable for bearing large stresses, tissue damage may occur. In addition, storage of excessive strain energy might lead to breakage of the tissue. [source] Masticatory performance in patients with anterior disk displacement without reduction in comparison with symptom-free volunteersEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2002Ingrid Peroz Masticatory function can be impaired by craniomandibular disorders. The aim of this study was to assess masticatory performance in patients with an anterior disc displacement (ADD) without reduction. In the experiments, 29 patients and 33 age- and gender-matched volunteers chewed artificial test food for 60 chewing strokes. The collected remains of the test food were filtered, dried, fractionated by a sieving procedure, and weighed. The particle size distribution was then described using a cumulative distribution function. Patients and controls were clinically examined, and patients were asked to complete a pain questionnaire. Comparison with controls, patients showed significantly reduced masticatory performance. Patients that had had a disorder longer than 3 yr tended to display less reduction of their masticatory performance. Neither the treatment methods used, nor restriction of daily life activities or pain intensity were significantly correlated with masticatory performance. Jaw mobility was significantly reduced in patients. More than half of the patients and none of the controls had joint noises and trigger points in the masticatory muscles. Pain was present, in particular, during chewing and maximal opening of the mouth. It was concluded that patients with ADD without reduction have a significantly reduced masticatory performance. [source] Clinical value of 12 occlusal features for the prediction of disc displacement with reduction (RDC/TMD Axis I group IIa)JOURNAL OF ORAL REHABILITATION, Issue 5 2009G. CHIAPPE Summary, The purpose of this study is to quantify the clinical value of 12 occlusal variables for the prediction of disc displacement with reduction diagnosed according to research diagnostic criteria (RDC)/temporomandibular disorder (TMD). Twelve occlusal features were clinically assessed by the same three operators. The sample consisted of 165 TMD patients (65 males, 100 females; mean age: 32·55 ± 11·685years) with only disc displacement with reduction (RDC/TMD Axis I group IIa) and a control sample of 145 healthy subjects (65 males, 80 females; mean age: 31·24 ± 12·436 years) diagnosed with RDC/TMD Axis I group 0. A stepwise multiple logistic regression model was used to identify the significant correlation between occlusal features and disease. The odds ratio for disc displacement was 2·84 for absence of canine guidance, 2·14 for mediotrusive interference and 1·75 for retruded contact position (RCP)/maximum intercuspation (MI) slide ,2 mm. Other occlusal variables did not reveal to be statistically significant. The percentage of the total log likelihood for disc displacement explained by the significant occlusal factors was acceptable with a Nagelkerke's R2 = 0·124. The final model including the significant occlusal features revealed an optimal discriminant capacity to predict patients with disc displacement with a sensitivity of 63·6% or with a specificity of 64·8% for healthy subjects and an accuracy of 64·2%. Occlusal features showed a low predictive value for detecting disc displacement. Multifactorial complex pathologies such as TMD should be investigated using a multivariate statistical analysis; moreover, the future of aetiopathogenic research in this matter requires a multifactorial approach. [source] Diagnostic sub-types, psychological distress and psychosocial dysfunction in southern Chinese people with temporomandibular disordersJOURNAL OF ORAL REHABILITATION, Issue 3 2008L. T. K. LEE Summary, The study aimed to assess the distribution of temporomandibular disorders (TMD) sub-types, psychological distress and psychosocial dysfunction in southern Chinese people seeking treatment for TMD using Research Diagnostic Criteria for TMD (RDC/TMD) and investigate potential cross-cultural differences in sub-type prevalence and psychosocial impact. Eighty-seven consecutive patients (77 females; 10 males) with a mean age of 39·3 years (s.d. 12·8) newly referred to the specialist TMD clinic at the Prince Philip Dental Hospital, Hong Kong over a 20-month period took part in the study. RDC/TMD history questionnaire and clinical assessment data were used to derive Axis I and II findings. Group I muscle disorders were the most common and found in 57·5% of patients. Group II (disc displacement) disorders were found in 42·5% and 47·1% of the right and left temporomandibular joints (TMJ) respectively. Group III disorders (arthralgia/arthrosis/arthritis) were revealed in 19·5% and 23·0% of right and left TMJ's respectively. In the Axis II assessment, 42·5% of patients had moderate/severe depression scores, 59·7% had moderate/severe somatization scores and based on graded chronic pain scores 15·0% had psychosocial dysfunction (grade III and IV). While acknowledging the small sample size, the distribution of RDC/TMD Axis I and II diagnoses was fairly similar in Chinese TMD patients compared with Western and other Asian patient groups. However, in Chinese patients, myofascial pain with limited jaw opening and TMJ disc displacement with reduction were more common and a significant number experienced psychological distress and psychosocial dysfunction. The findings have implications for the management of TMD in Chinese people. [source] Comparative prospective study on splint therapy of anterior disc displacement without reductionJOURNAL OF ORAL REHABILITATION, Issue 7 2005M. STIESCH-SCHOLZ summary A prospective randomized study was carried out to compare the therapeutic success of two different types of splint in patients with painful anterior disc displacement of the temporomandibular joint. The patients in Group I (n = 20) received stabilization splint therapy and the patients in Group II (n = 20) pivot splint therapy. Clinical investigation of the craniomandibular system was performed before and 1, 2 and 3 months after therapy and this was accompanied by subjective evaluation by the patients of their symptoms, using a validated questionnaire with visual analogue scales (VAS). There was a significant increase in maximum jaw opening and a significant reduction in subjective pain in both groups during the course of therapy (Wilcoxon test, P < 0·05). Active jaw opening increased by a mean of 8·05 mm in the group of patients treated with a stabilization splint (Group I). The comparable figure with pivot splint therapy (Group II) was 8·26 mm. The VAS scale value in Group I was reduced by 30·54 units and in Group II by 39·36 scale units. However, neither of these differences between the groups was statistically significant (Mann,WhitneyU -test, P > 0·05). It can be concluded that both types of splint provided effective therapy in patients with anterior disc displacement. [source] Comparison of ultrasonography and magnetic resonance imaging in the evaluation of temporomandibular joint disc displacementJOURNAL OF ORAL REHABILITATION, Issue 4 2005F. TOGNINI summary, The aim of this work was to evaluate the accuracy and reliability of ultrasonography in the diagnosis of temporomandibular joint (TMJ) disc position abnormalities compared with magnetic resonance imaging (MRI). Participants in this study were 41 consecutive patients with signs and symptoms of temporomandibular disorders. All 82 TMJs were evaluated to detect disc position abnormalities by means of ultrasonography and MRI, performed by blinded operators. The accuracy of ultrasonography was evaluated with respect to MRI. Ultrasonography demonstrated good accuracy in the evaluation of disc position, showing a sensitivity of 65·8% and a specificity of 80·4%, resulting in a positive likelihood ratio of 3·35, a negative likelihood ratio of 0·42, and a diagnostic odds ratio of 7·97. The predictive positive and negatives values were respectively 77·1% and 70·2% and the overall agreement between the two radiological techniques was 73·1%. Ultrasonography proved to be accurate in detecting normal disc position and the presence of abnormalities in disc,condyle relationship but not so useful for the distinction between disc displacement with and without reduction. [source] Body posture during sleep and disc displacement in the temporomandibular joint: a pilot studyJOURNAL OF ORAL REHABILITATION, Issue 2 2005H. HIBI summary, ,Many possible factors associated with internal derangement of the temporomandibular joint (TMJ) have been discussed, but the causal factors remain unproven. The present study aimed to investigate habitual body posture during sleep (HBP) of patients with anterior disc displacement (ADD) in the TMJ. The sample comprised 87 patients (12 males, 75 females) aged 13,68 years (mean 25 years) and diagnosed by magnetic resonance imaging as having unilateral or bilateral ADD in the TMJ. The HBPs were classified into five categories: supine, prone, right lateral, left lateral, and no-dominant positions. Of the 50 patients with the unilateral ADD, 33 (66%) had the ipsilateral HBP to the affected joint while none (0%) had the contralateral HBP. This contrast showed that the HBP was a possible contributing factor to the ADD. It was suggested that HBP allows the ipsilateral condyle to displace posteriorly and this posterior position causes relative ADD. [source] Mood and anxiety psychopathology and temporomandibular disorder: a spectrum approachJOURNAL OF ORAL REHABILITATION, Issue 10 2004D. Manfredini summary, Psychological factors play an important role in the aetiopathogenesis of temporomandibular disorders (TMD), as demonstrated by an increase in stress, anxiety, depression and somatization in TMD patients. The aim of this work was to investigate the presence of mood and panic-agoraphobic symptoms in different groups of TMD patients by means of a spectrum approach to psychopathology. A total of 131 subjects were included in this study and TMD signs and symptoms were investigated by means of a standardized clinical examination. Two self-report questionnaires were used to evaluate mood (MOODS-SR) and panic-agoraphobic (PAS-SR) spectrum. anova and Bonferroni's post hoc test for multiple comparisons were used to compare mean scores of all TMD groups for MOODS-SR, PAS-SR and all their domains. Results revealed a significantly higher prevalence of both mood (P < 0·001) and panic-agoraphobic (P < 0·01) symptoms in myofascial pain patients than in all other diagnostic groups (TMD-free, disc displacement and joint disorders). With regard to mood spectrum, strong differences emerged for all domains evaluating depressive symptoms. As for the panic-agoraphobic spectrum, myofascial pain patients differed from the other groups for the presence of stress sensitivity, panic, separation anxiety, hypochondriac and agoraphobic symptoms. It was concluded that myofascial pain patients differed from those with disc displacement, joint disorders and no TMD in relation to some psychopathological symptoms, while the last three groups presented very similar profiles. [source] Validation of the clinical diagnostic criteria for temporomandibular disorders for the diagnostic subgroup , disc derangement with reductionJOURNAL OF ORAL REHABILITATION, Issue 12 2002R. Emshoff summary, Research is needed to assess the validity of the clinical diagnostic criteria for temporomandibular disorders (CDC/TMD). The purpose of this study was to test the reliability of the clinical diagnosis of temporomandibular joint (TMJ) internal derangement type (ID)-I as compared with the magnetic resonance imaging (MRI) ,gold standard'. The study comprised 168 TMJs in 84 patients, who were assigned a clinical TMJ-related diagnosis of ID-I (disc displacement with reduction) in at least one TMJ. Bilateral sagittal and coronal MR images were obtained subsequently to establish the corresponding diagnosis of the disc,condyle relationship. For the CDC/TMD interpretations, the positive predictive value (PPV) of ID-I for disc displacement with reduction (DDR) was 44%, and for the presence of an ID 69%. The overall diagnostic agreement for ID-I was 47·6% with a corresponding K -value of 0·05. Most of the disagreement was the result of the false-positive interpretations of ID-I, and false-negative interpretations of an ,absence of ID'. The results suggest CDC/TMD for ID-I to be insufficient reliable for determination of ID and/or DDR. Patients assigned a clinical TMJ-related diagnosis of ID-I may need to be supplemented by evidence from MRI to determine the functional ,disc,condyle relationship'. [source] A case,control study of temporomandibular disorders: symptomatic disc displacementJOURNAL OF ORAL REHABILITATION, Issue 5 2002A. M. Velly This case,control study was designed to investigate the risk factors for disc displacement (DD) without myofascial pain (MFP). The study population included 59 cases with DD without MFP, selected in two hospital dental clinics, and 100 concurrent controls selected in one of these clinics. The association with DD was evaluated for bruxism, head,neck trauma, orthodontic treatment, and sociodemographic characteristics by using unconditional logistic regression. In the multivariate analysis, excluding psychological factors, an association was found between DD and clenching,grinding (OR=3·57; 95% CI: 1·27,9·98). This association persisted when anxiety (OR=3·07; 95% CI: 1·08,8·70) or depression (OR=4·02; 95% CI: 1·43,11·31) was included in the model. A positive association was noted between orthodontic treatment and DD (OR=3·10; 95% CI: 1·06,9·65). The effect between orthodontic treatment and DD remained and increased with the inclusion of anxiety (OR=3·65; 95% CI: 1·15,11·61) or depression (OR=3·20; 95% CI: 1·06,9·65). A high level of anxiety (OR=2·40; 95% CI: 1·01,5·73), was positively related to DD. We concluded that clenching combined with grinding, and orthodontic treatment are factors related to DD. The interpretation of these associations, however, requires caution because of the inclusion of prevalent cases. [source] Relationship between functional disc position and mandibular displacement in adolescent females: posteroanterior cephalograms and magnetic resonance imaging retrospective studyJOURNAL OF ORAL REHABILITATION, Issue 5 2002S. Nakagawa The purpose of this study was to investigate the relationship between the disc positions of temporomandibular joints (TMJ), the vertical and lateral mandibular displacement (VMD and LMD, respectively) and age in female adolescents with signs and symptoms of the temporomandibular disorders (TMD). The VMD and LMD were assessed, using posteroanterior (PA) cephalograms. The disc positions were assessed by magnetic resonance imaging (MRI) and categorized as follows: normal disc position, functional disc displacement and functional disc dislocation. Excluding patients with osteoarthritis, the total number of subjects was 54 female adolescents who were grouped into three: the bilateral normal disc position group, the unilateral or bilateral functional disc displacement group, and the unilateral or bilateral functional disc dislocation group. We compared the extent of VMD and LMD between the three groups, and investigated their correlation with age. Results indicate that functional disc displacement and dislocation are related to mandibular displacement, and VMD did not correlate with age but LMD did correlate with age. This study suggests that the onset of disc displacement is related to the mandibular displacement and disturbs normal growth of the mandible three-dimensionally. [source] Effectiveness of exercise therapy in patients with internal derangement of the temporomandibular jointJOURNAL OF ORAL REHABILITATION, Issue 12 2001P. Nicolakis This study intended in evaluating the effectiveness of exercise therapy in patients with craniomandibular disorders (CMD). Twenty consecutive patients suffering from CMD with anterior disc displacement without reduction consulting a CMD service were included in the study if they met following criteria: (i) pain in the temporomandibular region, (ii) reduced incisal edge clearance (<35 mm), (iii) magnet resonance imaging confirmed anterior disc displacement without reduction and (iv) evidence of postural dysfunction. All patients were assigned to a waiting list, serving as a no-treatment control period, according to a before,after trial. The treatment consisted of active and passive jaw movement exercises, correction of body posture and relaxation techniques. A total of 18 patients completed the study, no adverse effects occurred. Following main outcome measures were evaluated: (1) pain at rest (2) pain at stress (3) impairment (4) mouth opening at base-line, before and after treatment and at 6 month follow-up. As a result of treatment pain, impairment and mouth opening improved significantly more than during control period (paired samples t -test P < 0·05). After treatment four patients had no pain at all (chi-square: P < 0·05) and only seven patients revealed an impaired incisal edge clearance after treatment. (chi-square Test, P < 0·001). At follow up, seven patients had no pain and experienced no impairment. Exercise therapy seems to be useful in the treatment of anterior disc displacement without reduction. [source] Stress distribution in the temporomandibular joint affected by anterior disc displacement: a three-dimensional analytic approach with the finite-element methodJOURNAL OF ORAL REHABILITATION, Issue 9 2000Tanaka E. The purpose of this study was to investigate the influences of anterior disc displacement on TMJ loading during maximum clenching by use of finite-element analysis. Based on a young human dry skull, an analytic model of the mandible including the TMJ was developed. In addition to the standard model with normal disc,condyle relation, two models were designed to simulate various degrees of anterior disc displacement. In the standard model, compressive stresses were induced in the anterior, middle and lateral areas on the condyle and glenoid fossa, whereas tensile stresses were observed in the posterior and medial regions. In the models with anterior disc displacement, compressive stresses were recognized in all the areas of TMJ components excluding the bilaminar zone. Shear stresses in the articular disc and bilaminar zone significantly increased in most areas. In conclusion, stress distributions in the TMJ with a normal disc position was substantially different from those with anterior disc displacement, suggesting that the progress in disc displacement may have some association with the nature of stress distributions in the TMJ, in the articular disc in particular. [source] Static and dynamic mechanics of the temporomandibular joint: plowing forces, joint load and tissue stressORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 3 2009J Nickel Structured Abstract Authors,,, Nickel J, Spilker R, Iwasaki L, Gonzalez Y, McCall WD, Ohrbach R, Beatty MW, Marx D Objectives,,, To determine the combined effects 1) of stress-field aspect ratio and velocity and compressive strain and 2) joint load, on temporomandibular joint (TMJ) disc mechanics. Setting and Sample Population,,, Fifty-two subjects (30 ,; 22 ,) participated in the TMJ load experiments. Material and Methods,,, In the absence of human tissue, pig TMJ discs were used to determine the effects of variables 1) on surface plowing forces, and to build a biphasic finite element model (bFEM) to test the effect of human joint loads and 2) on tissue stresses. In the laboratory, discs received a 7.6 N static load via an acrylic indenter before cyclic movement. Data were recorded and analysed using anova. To determine human joint loads, Research Diagnostic Criteria calibrated investigators classified subjects based on signs of disc displacement (DD) and pain (+DD/+pain, n = 18; +DD/,pain, n = 17; ,DD/,pain, n = 17). Three-dimensional geometries were produced for each subject and used in a computer model to calculate joint loads. Results,,, The combined effects of compressive strain, and aspect ratio and velocity of stress-field translation correlated with plowing forces (R2 = 0.85). +DD/,pain subjects produced 60% higher joint loads (anova, p < 0.05), which increased bFEM-calculated compressive strain and peak total normal stress. Conclusions,,, Static and dynamic variables of the stress-field and subject-dependent joint load significantly affect disc mechanics. [source] Temporomandibular joint sound evaluation with an electronic device and clinical evaluationORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 2 2001R. A. Tanzilli Sound analysis to diagnose internal derangement has received much attention as an alternative to radiographic examination. The purpose of this study was to compare findings with an electronic device (sonography) and clinical examination to magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ). Twenty-three symptomatic patients (46 joints) were evaluated for this study. All patients had jaw joint pain and one or more of the following findings; limitation of jaw opening, painful mandibular movement with or without clicking or crepitation. The presence or absence of joint sounds was evaluated clinically by palpation and auscultation and with sonography. If sounds were present (clicking or crepitation) on either examination the patient was considered positive for disc displacement for that examination. Two by two tables were constructed comparing sonography and clinical examination with MRI findings. The sensitivity of the sonogram was 84% and the specificity was 33% when compared with MRI findings. The sensitivity of the clinical examination was 70% and the specificity was 40% when compared with MRI findings. This study suggests that clinical and sonographic examination has a high sensitivity (low false negative examinations) but low specificity (high false positive examinations). [source] | ||||||||||