The effect of age and gender on the onset of symptomatic temporomandibular joint disk displacement

Temporomandibular joint disc repositioning and occlusal splint for adolescents with skeletal class II malocclusion: a single-center, randomized, open-label trial

BACKGROUND

Temporomandibular joint (TMJ) disc repositioning through open suturing (OSu) is a new disc repositioning method. Its result for adolescents with condylar resorption and dentofacial deformities combined with and without postoperative occlusal splints (POS) has not been well studied.

OBJECTIVE

This study was to evaluate and compare the effects of OSu with and without POS in the treatment of TMJ anterior disc displacement without reduction (ADDwoR) in adolescent skeletal Class II malocclusion.

METHODS

A total of 60 adolescents with bilateral ADDwoR were enrolled in this study. They were randomly allocated into two groups: OSu with and without POS. Magnetic resonance imaging (MRI) and lateral cephalometric radiographs were used to measure changes in condylar height and the degree of skeletal Class II malocclusion from before operation and at 12 months postoperatively. Changes in these indicators were compared within and between the two groups.

RESULTS

After OSu, both groups exhibited significant improvements in condylar height and occlusion at the end of 12 months follow-up (P < 0.05). The group of OSu with POS had significantly more new bone formation (2.83 ± 0.75 mm vs. 1.42 ± 0.81 mm, P < 0.001) and improvement in dentofacial deformity than the group of OSu only (P < 0.05). The new bone height was significantly correlated with POS (P < 0.001), the changes of SNB (P = 0.018), overjet (P = 0.012), and Wits appraisal (P < 0.001).

CONCLUSION

These findings indicated that OSu can effectively stimulate condylar regeneration and improve skeletal Class II malocclusion in adolescents with bilateral ADDwoR. The results are better when combined with POS.

TRIAL REGISTRATION

This trial was prospectively registered on the chictr.org.cn registry with ID: ChiCTR1900021821 on 11/03/2019.

Magnetic resonance imaging assessment of articular disc position in temporomandibular disorder subjects with various bite registrations

Objective

This study aimed to evaluate the validity and reliability of three bite registrations on articular disc position in temporomandibular disorder patients using magnetic resonance imaging (MRI).

Materials and Methods

Fifteen clinically symptomatic and orthodontically untreated temporomandibular disorder patients within the age range of 17-40 years (mean age: 28.5 years) were examined. Each patient was subjected to three bite registrations, namely maximum intercuspation, initial contact bite and Roth power centric bite, and evaluated with MRI.

Results

On the right side, the mean vertical and horizontal measurement values of the point in the most posterior aspect of the posterior band of the articular disc in relation to horizontal reference line (HRL) and vertical reference line (VRL) in the sagittal view in the Roth power centric bite were lesser (2.720 ± 1.239 mm and 2.380 ± 1.185 mm, respectively), in comparison with the other two bites, and on the left side too, it was lesser in the Roth power centric bite (2.293 ± 0.979 mm and 2.360 ± 1.078 mm, respectively), when compared to the other two bites. Statistical analysis also showed the significance of Roth power centric bite over the other two bites.

Conclusions

Favourable articular disc positional changes were observed in the Roth power centric bite followed by the initial contact bite and that maximum disc recapture was observed in most patients with the Roth power centric bite rather than in initial contact bite and maximum intercuspation positions. The Roth power centric bite could be assumed to be the ideal method for articulation and fabrication of gnathological splints for treating patients with temporomandibular disorders.

Nonlinear Relationship between Temporomandibular Joint Disc Displacement Distance and Disc Length: A Magnetic Resonance Imaging Analysis

Objective: to explore the association between the distance of disc displacement and disc morphology in patients with temporomandibular disorders (TMDs). Methods: a total of 717 joints in 473 subjects were enrolled in this cross-sectional study. The magnetic resonance imaging (MRI) of each patient was evaluated for temporomandibular joint (TMJ) disc morphology classification and position. The distance of the disc displacement and disc length were measured for smoothing spline prediction. A stratified analysis was performed based on the types of disc positions. The disc width and length-width ratio (L/W) were also measured. Descriptive statistics, one-way analysis of variance, smoothing spline analysis, threshold analysis, and two piecewise linear regression were performed to investigate the association between the displacement distance and length of discs. Results: the differences in displacement distance among morphological categories and among different disc positions were statistically significant. Nonlinear relationships were found between distance and length in all subjects. Two turning points of distance (−1.8 mm and 1.7 mm) were found, dividing the curve into three segments. Disc width and L/W were significantly different among discs in the three segments of the curve. The correlation coefficient (β) for the three segments were as follows: −0.6 [95% confidence interval (CI) = −0.9 to −0.3, p < 0.001], 0.0 (95% CI = −0.1 to 0.0, p = 0.027), and −0.7 (95% CI = −0.8 to −0.7, p < 0.001). Nonlinear relationships were also found between the distance and length in cases with anterior disc displacement (ADD), anterior disc displacement with reduction (ADDWR), and without reduction (ADDWoR). Conclusion: the turning points of the disc displacement distance may be considered as a potential reference value for high-risk disc deformation and ADD. Disc length decreases sharply with anterior disc displacement when the disc displacement distance is over 1.7 mm. Prospective and long-term studies are required to clarify the natural course of the disc at different stages of the regression curve.

Effects of occlusal splint and exercise therapy, respectively, for the painful temporomandibular disorder in patients seeking for orthodontic treatment: a retrospective study

OBJECTIVE

To evaluate the effect of hard stabilization splints (HSS), counselling and exercise therapies, respectively, for the painful temporomandibular disorder (TMD) in patients seeking for orthodontic treatment through magnetic resonance imaging (MRI) and clinical examination.

MATERIALS AND METHODS

Eighty-seven TMD patients were divided into two groups according to their therapies: the HSS group (n = 43) comprising of patients treated with HSS, counselling and masticatory muscle exercises; the control group (n = 44) comprising of patients treated with counselling and masticatory muscle exercises alone. All patients had orthodontic therapies after the first treatment phase. The joint pain and clicking of all patients were recorded via clinical examination. MRIs of HSS groups were taken before (T₀), after the first phase (T₁), and after the orthodontic treatment (T₂). Parameters indicating the condyles and articular discs were evaluated. Clinical symptom (pain and clicking) changes among T₀, T₁ and T₂ time point were detected in the two groups respectively. The significant differences between HSS and control groups, as well as between male and female were tested at T₁ and T₂. Position changes of condyles and discs in HSS group among T₀, T₁ and T₂ were detected in male and female respectively.

RESULTS

After the first treatment phase, there was no difference in the decrease of facial pain between the two group, as well as between male and female in the two groups (P > 0.05). Clicking decreasing was not statistically significant. After the whole orthodontic periods, the TMJ pain relapsed in female of the control group, and the number of female's pain joints was more than male's (P < 0.05). In the HSS group, the posterosuperior movements of discs and the anteroposterior movements of condyles were recorded in closing position (P < 0.05). After the whole orthodontic periods, female's disc-condyle angles increased, the discs to HRP distance decreased and condyles to VRP distance increased when compared with the data of T₁ (P < 0.05).

CONCLUSIONS

For the orthodontic patients with painful TMD, HSS combined with counselling and exercise therapies before orthodontic treatment could provide pain relief. HSS is helpful to improve the position and relation of discs and condyles. In addition, male's prognosis is better than female's in terms of stability.

Inclination of the osseous components of the temporomandibular joint related with disc displacement: Magnetic resonance and cone beam computed tomography imaging-based study

OBJECTIVE

To assess the association between three-dimensional inclination of the osseous structures of temporomandibular joints (TMJ) and the risk of disc displacement (DD).

METHODS

The 120 TMJs of 60 patients were evaluated. According to magnetic resonance images, disc position was classified as normal, anterior DD with reduction (ADDWR) and without reduction (ADDWoR) and as normal, medial DD (MDD), and lateral DD (LDD) on the sagittal and coronal views, respectively. Condyle and eminence inclinations were measured using cone beam computed tomography.

RESULTS

Smaller horizontal condylar inclination was associated with ADDWoR (p < 0.05). Larger coronal condylar inclination was associated with ADDWR (p < 0.05) and LDD (p < 0.05). There was no association between sagittal eminence inclination and DD (p < 0.05).

CONCLUSION

Medial condylar rotation in the axial view may be associated with ADDWoR. The condyle head horizontally inclined in the coronal view may be associated with ADDWR and LDD.

MRI investigation of TMJ disc and articular eminence morphology in patients with disc displacement

PURPOSE

The aim of this study was to evaluate the morphology of the temporomandibular joint (TMJ) articular eminence and disc and the relationship between morphology and inclination in patients with disc displacement.

METHODS

TMJ magnetic resonance images (MRI) of 30 patients with disc displacement with reduction (DDWR) on one side and disc displacement without reduction (DDWOR) on the other side were analyzed. Articular eminence morphology was subdivided as box, sigmoid, flattened and deformed. Articular disc configuration was characterized as biconcave, biplanar, biconvex, hemiconvex and folded. The articular eminence inclination was measured as the angle between the Frankfurt plane and a line drawn from the glenoid fossa roof to the lowest point of the articular eminence.

RESULTS

Regarding articular eminence shape, in both DDWR and DDWOR groups, the most frequent articular eminence shape was flattened shape. Regarding to the disc morphology, biplanar shape was the most frequently observed in both DDWR side and DDWOR side. The mean articular eminence inclination was 32.62 and 33.85 in the DDWR and DDWOR side, respectively.

CONCLUSIONS

Disc and articular eminence morphology was found to have no relationship with TMJ internal derangement except the relationship between flattened type and internal derangement. The articular eminence inclination have no influence on disc reduction.

Temporomandibular joint anterior disc displacement with reduction in a young population: Prevalence and risk indicators

BACKGROUND

Temporomandibular joint (TMJ) anterior disc displacements with reduction (ADDR) are commonly found in the young population and often found to be associated with biomechanical and anatomical factors. Until now, most knowledge on ADDR among children and adolescents comes from studies performed on Caucasian subjects.

AIMS

To assess the clinically determined prevalence rates of ADDR among the young Indonesian population and to evaluate its risk indicators.

DESIGN

In this cross-sectional study, 1562 pupils and students of 7-21 years old completed a questionnaire and underwent a clinical examination.

RESULTS

The prevalence rates of ADDR were 7.0% among children (7-12 years), 14.4% among adolescents (13-18 years), and 12.3% among young adults (19-21 years). Logistic regression analyses revealed that increasing age and lip biting were associated with ADDR in children, whereas pen biting was associated with ADDR in the adolescent population. None of the included factors were found to be associated with ADDR in the young adult population.

CONCLUSIONS

The present findings indicate that prevalence of ADDR increases with age, with a peak during the years of adolescence. Biomechanical factors seem to play a significant role in ADDR development.

Evaluation of occlusion types, pain severity, and onset of complaints in 127 patients with temporomandibular disorders: A retrospective study

Objective: The aims of this study are to evaluate if occlusal types affect the type of temporomandibular disorders and if the onset of complaints are related to the type of internal derangements. Methods: One hundred thirty-four patients were evaluated. Occlusion types were grouped as Angle Class I, II, and III. The temporomandibular disorders were classified as masticatory muscle disorders, anterior disc dislocation with reduction, and anterior disc dislocation without reduction. Results: No significant relationships were found between the occlusion types, pain severity, the onset of the complaints, and the temporomandibular disorders. Premature contacts were found to be significantly higher in Class II and Class III patients, but no significant relations were found between premature contacts and temporomandibular disorders. Discussion: Occlusal features are not discriminant factors in the occurrence of temporomandibular disorders. Also, it cannot be concluded that the longer the patients have temporomandibular disorders, the higher their pain scores will be.

Correlation between age, gender, and the number of diagnoses of temporomandibular disorders through magnetic resonance imaging: A retrospective observational study

OBJECTIVE

The aim of this study was to evaluate the correlation among age, gender and the number of temporomandibular disorder (TMD) findings.

METHODS

The records from 228 patients with TMD were analyzed for the presence of these findings: morphological changes, disc displacement with reduction (DDWR) and without reduction (DDWOR), bone edema, effusion, and avascular necrosis. Statistical analyses were conducted using multinomial regression with a 5% significance level.

RESULTS

DDWR was the most frequent finding. Group 1 was composed of 94 patients (41.22%), Group 2, of 67 patients (29.38%), and Group 3, of 67 patients (29.38%). Men were significantly less likely to belong to Group 3 than women (p = 0.5517). Older patients were slightly more likely to fall in Groups 2 and 3 than in Group 1.

DISCUSSION

Women were shown to be more susceptible to developing a higher number of concomitant conditions than men, and the number of findings tended to increase with age.

Correlation between clinical variables and magnetic resonance imaging findings in symptomatic patients with chronic temporomandibular articular disc displacement with reduction: A retrospective analytical study

Objective: To correlate the clinical aspects of symptomatic patients with chronic articular disc displacement with reduction with alterations in the articular disc (AD) morphology and sagittal position. Methods: Records from 109 patients were selected that included data on AD morphology and sagittal position as determined by MRI. According to the MRI results, the sagittal position and AD morphology with opened and closed mouth were correlated with many clinical variables. Results: More than half of the patients studied were female, and the biconcave and hemiconvex morphologies were most common. Thirty-four patients (31.3%) presented with restricted maximum interincisal distance (MID). The biplanar morphology was associated with eccentric bruxism and MID (p < 0.05). Visual analog scale (VAS) scores between 2 and 7 were shown to be risk factors (p < 0.05). Conclusion: The mouth position can influence AD morphology and eccentric bruxism. VAS scores and unknown etiology were risk factors.

The Prevalence of Oropharyngeal Dysphagia in Adults Presenting with Temporomandibular Disorders Associated with Rheumatoid Arthritis: A Systematic Review and Meta-analysis

Temporomandibular disorders (TMDs) are the most frequent non-dental orofacial pain disorders and may be associated with rheumatoid arthritis (RA), resulting in oropharyngeal dysphagia (OD). However, clinicians' understanding of involvement with OD caused by RA-related TMDs is limited and the methodological quality of research in this field has been criticised. Therefore, the aim of this study was to systematically review the prevalence of oral preparatory and oral stage signs and symptoms of OD in adults presenting with TMDs associated with RA. A systematic review of the literature was completed. The following electronic databases were searched from inception to February 2016, with no date/language restriction: EMBASE, PubMed, CINAHL, Web of Science, Elsevier Scopus, Science Direct, AMED, The Cochrane Database of Systematic Reviews, and ProQuest Dissertations and Theses A & I. Grey literature and reference lists of the included studies were also searched. Studies reporting the frequency of OD in adults presenting with TMD and RA were included. Study eligibility and quality were assessed by three independent reviewers. Methodological quality was assessed using the Down's and Black tool. The search yielded 19 eligible studies. Typical difficulties experienced by RA patients included impaired swallowing (24.63%), impaired masticatory ability (30.69%), masticatory pain (35.58%), and masticatory fatigue (21.26%). No eligible studies reported figures relating to the prevalence of weight loss. Eligible studies were deemed on average to be of moderate quality. Study limitations included the small number of studies which met the inclusion criteria and the limited amount of studies utilising objective assessments. Valid and reliable prospective research is urgently required to address the assessment and treatment of swallowing difficulties in RA as TMJ involvement may produce signs and symptoms of OD.

Internal derangement in the temporomandibular joint of juveniles with clinical signs of TMD : MRI-assessed association with skeletal and dental classes

AIM

The aim of this study was to investigate possible correlation of specific skeletal or dental class in children and adolescents with clinical signs of temporomandibular dysfunction (TMD) with the severity of internal derangement (ID) of the temporomandibular joint.

MATERIALS AND METHODS

Based on MRI images, the ID of 232 juvenile temporomandibular joints in 116 patients were retrospectively recorded. The distribution of the ID stages within the skeletal and dental classes was compared by means of the χ ² test.

RESULTS

Excluding the comparison between skeletal Class I (S I) and skeletal Class II (S II; p < 0.05), no statistically significant differences in the distribution of the ID stages were found between the skeletal classes (p > 0.05). No statistically significant differences were found when comparing the distribution of the ID stages between the dental classes (p > 0.05).

CONCLUSION

According to these findings, there is no skeletal or dental class that is related to higher degrees of internal derangement in the TMJs of children and adolescents presenting clinical signs of TMD. Therefore, it is not possible to draw conclusions about the severity of the ID in relation to the dental and skeletal class in symptomatic juvenile TMJs.

Bilateral TMJ Disk Displacement Induces Mandibular Retrognathia

Unilateral non-reducing TMJ disk displacement has been shown to retard mandibular growth on the ipsilateral side, with facial asymmetry a sequela. We hypothesized that bilateral affliction would impair mandibular growth bilaterally, generating mandibular retrognathia. Non-reducing TMJ disk displacement was surgically created in 10 growing New Zealand White rabbits. Ten additional rabbits served as a sham-operated control group. Facial growth was followed in serial cephalograms, with tantalum implants, during a period corresponding to childhood and adolescence in man. The results verified that bilateral non-reducing TMJ disk displacement retarded mandibular growth bilaterally, the extent corresponding to mandibular retrognathia in man. Maxillary growth was also retarded, but to a lesser degree. Growth impairment fluctuated over time, the most striking retardation occurring during periods of general growth acceleration. This should be taken into consideration when orthodontic treatment, aimed at stimulating mandibular growth, is initiated in adolescent individuals with non-reducing TMJ disk displacement.

Changes in disc status in the reducing and nonreducing anterior disc displacement of temporomandibular joint: a longitudinal retrospective study

Treatment procedures for anterior disc displacement (ADD) of temporomandibular joint (TMJ) are far from reaching a consensus. The aim of the study was to evaluate disc status changes of anterior disc displacement with reduction (ADDWR) and without reduction (ADDWoR) comparatively, to get a better understanding of the disease progress without intervention. This longitudinal retrospective study included 217 joints in 165 patients, which were divided into ADDWR group and ADDWoR group based on magnetic resonance imaging (MRI) examination. The joints were assessed quantitatively for disc length and displacement distance at initial and follow-up visits. Disc morphology, which was classified in 5 types, was also evaluated. Paired t-test and Wilcoxon signed rank test were used to assess intra-group differences and independent t-test for inter-group differences. Moreover, analysis of covariance was applied to analyze influential factors for changes in disc length and displacement distance. According to our results, discs tended to become shorter, move further forward and distort more seriously in ADDWoR group than in ADDWR group after follow-up. Moreover, discs were prone to become shorter and more anteriorly displaced in teenagers, type I and III morphologies, advanced Wilkes stages, or those with joint effusion. Follow-up period seemed to be not critical.

Directional characteristics of incipient temporomandibular joint disc displacements: A magnetic resonance imaging study

INTRODUCTION

Disc displacement (DD) is common in adolescents, but not much is understood about its cause. Assessment of the directionality of incipient DDs may provide clues about the etiology.

METHODS

The sample consisted of magnetic resonance images of 143 temporomandibular joints with incipient DD from 89 preorthodontic patients (mean age, 10.8 years). The severity of DD was evaluated by grading the degree of displacement depicted in the images in the sagittal and coronal planes, and each incipient DD was categorized based on the directionality.

RESULTS

Of the 143 incipient DDs, rotational anterolateral DD (43.36%) and partial anterior DD in the lateral portion (27.27%) were the most common; rotational anteromedial DD (9.09%) and partial anterior DD in the medial portion (1.40%) accounted for only 10.49%. Anterior DD was seen in 12.59%. Pure sideways shift was rare; lateral DD was seen in 2.80%, and medial DD in 3.50%. Thus, the lateral part of the joint was involved in a majority of the incipient DDs and the medial part far less. No sex difference was noted in this trend, but the difference between the right and left sides was statistically significant.

CONCLUSIONS

These results indicate a predilection for the lateral part of the joint in incipient DDs and may have etiologic implications.

Imaging Approach to Temporomandibular Joint Disorders

Internal derangement is the most common temporomandibular joint disorder. Degenerative osteoarthritis and trauma are next in frequency. Less common pathology includes rheumatoid arthritis, synovial chondromatosis, calcium pyrophosphate dehydrate deposition disease, pigmented villonodular synovitis, tumors, infection, and osteonecrosis. We provide a systematic approach to facilitate interpretation based on major anatomic structures: disc-attachments, joint space, condyle, and lateral pterygoid muscle. Relevant graphic anatomy and state of the art imaging are discussed in correlation with current clinical and therapeutic highlights of pathologic entities affecting the joint.

Subtyping Somatic Tinnitus: A Cross-Sectional UK Cohort Study of Demographic, Clinical and Audiological Characteristics

Somatic tinnitus is the ability to modulate the psychoacoustic features of tinnitus by somatic manoeuvres. The condition is still not fully understood and further identification of this subtype is essential, particularly for the purpose of establishing protocols for both its diagnosis and treatment. This study aimed to investigate the characteristics of somatic tinnitus within a large UK cohort using a largely unselected sample. We believe this to be relatively unique in comparison to current literature on the topic. This was investigated by using a total of 608 participant assessments from a set of recognised tinnitus and audiology measures. Results from a set of chi-square tests of association found that amongst the individuals with somatic tinnitus, a higher proportion had pulsatile tinnitus (different from heartbeat), were under the age of 40, reported variation in the loudness of their tinnitus and reported temporomandibular joint (TMJ) disorder. The same pattern of results was confirmed using a multivariate analysis of the data based on logistic regression. These findings have strong implications towards the profiling of somatic tinnitus as a distinct subtype of general tinnitus.

Correlation between temporomandibular joint morphology and disc displacement by MRI

OBJECTIVES

The aim was to evaluate the morphology of the temporomandibular joint's (TMJs) disc and condyle as well as its correlation with disc displacement, using MRI.

METHODS

190 TMJs were retrospectively analysed. The condyle morphology of each TMJ was evaluated by two observers using both axial and coronal views, as were their disc morphology and displacement, using sagittal view. Condyle morphology was classified as flat, convex, angled or rounded in the coronal sections and as anterior side flat/posterior side convex, biconvex, anterior side concave/posterior side convex, flat or biconcave in the axial view. Disc morphology was determined as biconcave, biplanar, biconvex, hemiconvex or folded. χ2, Fisher exact and Bonferroni correction tests were used to evaluate the data. ANOVA followed by post hoc Tukey's test was used to evaluate the interaction between age and disc displacement.

RESULTS

Anterior disc displacement with reduction; convex condyle morphology in the coronal view; anterior side concave/posterior side convex morphology in the axial view; and biconcave discs were found to be the most prevalent findings. An association was observed between disc morphology and disc displacement (p<0.001). No correlation between condyle morphology and TMJ disc displacement was found (p=0.291 for axial and p=0.14 for coronal views).

CONCLUSIONS

The results of this study suggest that TMJ disc morphology is associated with disc displacement.

Influence of temporomandibular joint disc displacement on craniocervical posture and hyoid bone position

INTRODUCTION

The purpose of this study was to evaluate craniocervical posture and hyoid bone position in orthodontic patients with temporomandibular joint (TMJ) disc displacement.

METHODS

The subjects consisted of 170 female orthodontic patients who consented to bilateral magnetic resonance imaging of their TMJs. They were divided into 3 groups based on the results of magnetic resonance imaging of their TMJs: bilateral normal disc position, bilateral disc displacement with reduction, and bilateral disc displacement without reduction. Twenty-five variables from lateral cephalograms were analyzed with 1-way analysis of variance to investigate differences in craniocervical posture and hyoid bone position with respect to TMJ disc displacement status. Pearson correlation coefficients were calculated to analyze the relationships between craniofacial morphology and craniocervical posture or hyoid bone position.

RESULTS

Subjects with TMJ disc displacement were more likely to have an extended craniocervical posture with Class II hyperdivergent patterns. The most significant differences were found between patients with bilateral normal disc position and bilateral disc displacement without reduction. However, hyoid bone position in relation to craniofacial references was not significantly different among the TMJ disc displacement groups, except for variables related to the mandible. Pearson correlation coefficients indicated that extended craniocervical posture was significantly correlated with backward positioning and clockwise rotation of the mandible.

CONCLUSIONS

This suggests that craniocervical posture is significantly influenced by TMJ disc displacement, which may be associated with hyperdivergent skeletal patterns with a retrognathic mandible.

Severe retrognathia as a risk factor for recent onset painful TMJ disorders among adult females

OBJECTIVE

To evaluate the importance of severe retrognathia as a risk factor for the development of recent onset painful TMJ disorders among adult females.

DESIGN

Case-control study.

SETTING

This study was conducted in a large health maintenance organization between 1998 and 1999 [Kaiser Permanente Northwest (KPNW), Portland, OR, USA].

PARTICIPANTS

Adult females with recent onset painful TMJ disorders (n=29) and normal controls (n=104).

METHODS

Cases were recruited from the TMD clinic at Kaiser Permanente Northwest (KPNW). Controls were recruited from a dental clinic at KPNW. Case status was determined using a questionnaire; mandibular sagittal position was determined by measuring a research angle on facial photographs. The mean research angle for cases was compared to the mean for controls. Multivariable exact conditional logistic regression analysis was used to examine the demographic characteristics of cases and controls, and to determine the strength of association between recent onset painful TMJ disorders and severe retrognathia. The population attributable risk percentage (PAR%) and the attributable risk percentage (AR%) were calculated to further evaluate severe retrognathia as a risk factor.

RESULTS

The mean research angle among cases (67.7 degrees; 95% CI=66.0-69.4) was smaller than among controls (71.6 degrees; 95% CI=70.7-72.5, P<0.001). The odds ratio for the association between case status and the presence or absence of severe retrognathia was elevated (OR=6.3; 95% CI=1.1-47.5, P=0.039). The PAR% and AR%, associated with severe retrognathia, were 13.3 and 84.1%, respectively.

CONCLUSIONS

Severe retrognathia is strongly associated with recent onset painful TMJ disorders (OR=6.3). Only a small proportion of these disorders are attributable to severe retrognathia among the total population of adult females (PAR%=13.3%). However, a large proportion of these TMJ disorders are potentially attributable to severe retrognathia among adult females with severe retrognathia (AR%=84.1%).

Magnetic resonance imaging of temporomandibular joint dysfunction-correlation with clinical symptoms, age, and gender

OBJECTIVE

To determine whether the morphological (magnetic resonance imaging) MRI manifestations correlate with the signs and symptoms of temporomandibular joint (TMJ) dysfunction according to gender and age of the patients.

STUDY DESIGN

One hundred and forty-four subjects with TMJ dysfunction underwent a MRI of both TMJ to establish the presence of disk displacement, osteoarthritis, and effusion. Chi-square test and logistic regression analysis were preformed. For the comparison of mean values between samples, we used T-test.

RESULTS

A significant relationship between symptoms and morphological manifestations was found. In the group without reduction there were significant increases in the risk of experiencing symptoms (P = .002). Significant correlation between age and osteoarthritis (P = .001) and age and effusion (P = .022) was found. There was no correlation between gender and morphological manifestations.

CONCLUSION

MRI morphological manifestations of the TMJ correlate with the presence of symptoms, therefore MRI has a crucial role in the diagnosis of TMJ dysfunction.

Prevalence of disc displacement of various severities among young preorthodontic population: a magnetic resonance imaging study

PURPOSE

There has been no study on the prevalence of disc displacement (DD) of different levels in children and adolescents with adequate sample size using magnetic resonance images (MRIs). This retrospective cross-sectional study was designed to investigate the relationship between increasing age and the prevalence of DD of various severities in a young preorthodontic population.

MATERIALS AND METHODS

Of 199 preorthodontic patients aged 6 to 15 years visiting a private orthodontic office for initial examination, 153 patients with signs and symptoms of temporomandibular joint (TMJ) disorders had MRIs of their TMJs taken for further evaluation. Of those, 302 TMJs from 151 patients' MRIs of diagnostic quality were divided into three age groups (I: 6 to 9, II: 10 to 12, and III: 13 to 15 years). DD of each patient was categorized based on its severity from stage 0 (normal) to stage 4 (total DD without reduction). The distribution of DD stages in each age group was plotted on a line graph and statistically analyzed for intergroup comparison.

RESULTS

A graphical representation of the results clearly demonstrated a trend for higher occurrence of more advanced DD with an increase in age. No gender difference was observed. Statistical analysis showed that DD was significantly more advanced in group II than group I (p < 0.01) and group III than group I (p < 0.01).

CONCLUSIONS

The study revealed a high prevalence of DD in the young preorthodontic population and significant increase in the proportion of patients with more advanced stages of DD in older patients.

Influence of defective complete dentures renewal on TMD; an MRI and clinical controlled prospective study

BACKGROUND

The influence of complete denture occlusion on temporomandibular disorder (TMD) is controversial. Some studies found that defective occlusion contributes to the development of TMD, while others found no correlation.

OBJECTIVE

This prospective controlled study evaluated the relationship between renewal of old defective complete dentures and TMD as evidenced both by clinical examination and magnetic resonance imaging (MRI) findings.

MATERIALS AND METHODS

The study included 25 complete denture patients with signs and symptoms of TMD and 21 asymptomatic controls. Clicking was a common finding in all symptomatic joints. All selected participants needed complete denture renewal. MRI and clinical assessment following research diagnostic criteria for TMD guidelines (RDC/TMD) were carried out at baseline and 2 years after new complete denture insertion. Temporomandibular joint (TMJ) pain, muscle pain, clicking and movement limitation were the assessed signs and symptoms. MRIs were conducted to evaluate the TMJs for disc displacement, disc morphology and joint effusion.

RESULTS

Complete denture renewal significantly improved the signs and symptoms of TMD in symptomatic group (p < 0.01). Only in the symptomatic group, treatment resulted in a significant increase in joints displaying superior (normal) disc position (symptomatic p < 0.001; asymptomatic p = 0.157). New dentures did not affect disc morphology in both groups (p = 0.5 for both groups) but significantly reduced joint effusion in the symptomatic group (symptomatic p < 0.001; asymptomatic p = 0.5). Relationship between clinical and MRI findings was not one to one.

CONCLUSIONS

New complete dentures had a positive impact on TMD signs and symptoms, disc position and joint effusion but not on disc morphology.

MR imaging of the temporomandibular joint

MR imaging allows detailed evaluation of temporomandibular (TMJ) anatomy because of its inherent tissue contrast and high resolution. Joint biomechanics can be assessed through imaging patients in the closed and open jaw positions. Despite the accuracy of MR imaging in detecting disc position, results must be interpreted together with clinical findings, because an anteriorly displaced disc can be seen in up to one-third of asymptomatic patients, and a normal disc position can be seen in up to one-quarter of symptomatic patients. Interpretation of MR imaging requires knowledge of the normal anatomy and an understanding of normal and abnormal biomechanics.

Evaluation of bone changes in the temporomandibular joint using cone beam CT

OBJECTIVE

The aim of this study was to assess bone changes and mobility in temporomandibular joints (TMJs) using cone beam CT (CBCT) in a population sample in Recife, PE, Brazil.

METHODS

The TMJ images of patients treated by a radiologist at a private dental radiology service over a period of 1 year were retrieved from the computer database and assessed using a computer with a 21-inch monitor and the iCAT Cone Beam 3D Dental Imaging System Workstation program (Imaging Sciences International, Hatfield, PA). The Pearson χ(2) test was used to analyse the differences in percentage of bone changes among the categories of mobility (p ≤ 0.05). The McNemar test was used to compare the presence of bone changes in TMJs on the right and left sides (p ≤ 0.05).

RESULTS

An adjusted logistic regression model was used to assess the effect of age and gender on the occurrence of bone changes (p ≤ 0.05). Bone changes were present in 227 (71%) patients. Age group and gender showed a statistically significant association with presence of bone changes (p ≤ 0.05). There was no significant difference between the right and left sides (p = 0.556) and in condylar mobility (p = 0.925) with regard to the presence of degenerative bone changes.

CONCLUSIONS

There is a high prevalence of degenerative bone alteration in TMJs, which is more frequent in women and mostly located in the condyle. The prevalence of degenerative bone changes increases with age. There is no correlation between condylar mobility and the presence of degenerative bony changes in TMJs.

TMJ osteoarthritis: a new approach to diagnosis

Disorders of the temporomandibular joint (TMJ), including TMJ osteoarthritis (TMJ OA), are the topic of intensive clinical research; however, this is not the case in the archaeological literature, with the majority of work on the subject ceasing with the early 1990s. The methods employed in the diagnosis of TMJ OA within the archaeological work appear nonrepresentative of the disease and may have led to erroneous assumptions about the pattern and prevalence of OA. This current work presents a new method for evaluating OA specifically for the TMJ, considering both the biomechanics of the joint and the mechanisms of the disease. Totally, 496 specimens (including a group of modern documented specimens) were analyzed for the presence of TMJ OA using the following criteria: eburnation, osteophytes (marginal and new bone on joint surface), porosity, and alteration to joint contour. The results suggest that eburnation occurs rarely in the TMJ, so should not be used as an exclusive criterion. Rather a combination of at least two of the other criteria should be used, with osteophytes and porosity occurring the most frequently on both the mandibular condyle and articular eminence. Additionally, the prevalence of TMJ OA in the modern assemblage was similar to that observed in current clinical research, suggesting that the method employed here was able to produce a reasonable approximation of what is found in contemporary living populations.

Perceived symptoms of psychological distress and salivary cortisol levels in young women with muscular or disk-related temporomandibular disorders

OBJECTIVE

To assess any differences in psychological and endocrine variables between homogeneous core groups of young women with well-defined muscle- or disk-related temporomandibular disorders (TMDs) and matched controls.

MATERIAL AND METHODS

Fifteen women, aged 18-24 years, fulfilling the TMD Research Diagnostic Criteria I a/b (but not II or III) and 15 fulfilling the II a/b and III criteria were consecutively selected from referrals to an orofacial pain/TMD clinic. Thirty consecutive healthy age-matched women attending yearly routine check-ups at a general dental clinic served as controls. All 60 subjects answered a questionnaire, the Profile of Fatigue Related Symptoms (PFRS), and salivary samples on waking were collected for analysis of cortisol levels.

RESULTS

Symptom duration and pain levels were similar irrespective of muscle- or disk-related symptoms. Both diagnostic groups obtained scores that were similar and significantly higher than those of controls in all four scales of the PFRS: fatigue, emotional distress, cognitive difficulties and somatic symptoms. Salivary cortisol levels on waking did not differ between patients and controls.

CONCLUSIONS

Patients with TMDs, irrespective of diagnosis, appeared to be more psychologically distressed than controls evaluated psychometrically, which is in line with earlier findings. A corresponding difference was not reflected in a single measurement of morning salivary cortisol. A more comprehensive evaluation of endocrine variables is probably necessary to reveal whether any differences actually exist in this respect.

Assessment of optimal condylar position with limited cone-beam computed tomography

INTRODUCTION

There are no quantitative standards for the optimal position of the mandibular condyle in the glenoid fossa. Recently developed limited cone-beam computed tomography (LCBCT) allows measurement of this position with high accuracy.

METHODS

LCBCT was used to assess 24 joints in 22 symptom-free subjects (10 male, 12 female; mean age, 18 years) who had no disc displacement as verified by magnetic resonance imaging. Their joints had optimum function with the starting and end points of all functional jaw movements coincident with maximum intercuspation. Linear measurements of anterior space (AS), superior space (SS), and posterior space (PS) were made to determine the position of the condyle for each joint.

RESULTS

The mean AS, SS, and PS values were 1.3 mm (SD +/- 0.2 mm), 2.5 mm (SD +/- 0.5 mm), and 2.1 mm (SD +/- 0.3 mm), respectively. The ratio of AS to SS to PS was 1.0 to 1.9 to 1.6. No significant sex difference was noted in joint space distances. The results showed less variability of condylar position in the fossa than previously reported in normal subjects.

CONCLUSIONS

These data from optimal joints might serve as norms for the clinical assessment of condylar position obtained by LCBCT.

Analysis of magnetic resonance images of disk positions and deformities in 1,265 patients with temporomandibular disorder

Objectives

To compare MRI manifestations according to gender and age and to identify correlations between clinical manifestations and MRI findings in patients with temporomandibular disorder (TMD) as based on a large series.

Materials and Methods

Fat suppressed oblique sagittal images of the open and closed mouth were acquired, and MRI scanning parameters were applied.

Results

The patients consisted of 946 females (average, 36.6 years old), and 319 males (average, 34.3 years old). In all TMD patients, 945 had symptoms in the unilateral temporomandibular joint (TMJ) and 320 in the bilateral TMJ. There were significant differences in the distribution of disk positions based on age, regardless of gender, in the unilaterally and bilaterally symptomatic groups; however, the results were not significant in the asymptomatic group. There were significant differences with respect to the distribution of disk positions between males and females in asymptomatic group and in the unilaterally symptomatic group, although the bilaterally symptomatic group did not show significant differences in this regard. As regards the disk positions in the joints of the three groups (asymptomatic group, unilaterally and bilaterally symptomatic groups), there were significant interactive effects of disk positions, regardless of gender. There were statistically significant age-related differences in disk deformities in all symptom groups, regardless of gender, except for in the group of males lacking symptoms in either joint. As regards disk deformities among the three groups studies here, there were significant interactive effects for disk positions, regardless of gender.

TMD and occlusion part I. Damned if we do? Occlusion: the interface of dentistry and orthodontics

OBJECTIVES

To review how occlusion, facial growth, TM disc position and malocclusion may relate to TMD; to review clinical studies investigating TMD pre- and post-orthodontic treatment as well as other studies linking occlusal features with TMD highlighting their limitations; and to make suggestions for improved study designs in the future in order to provide an evidence-base for clinical practice.

DESIGN

Review article.

METHODS

Electronic databases (MEDLINE and the Cochrane Database of Systematic Reviews) were used to select relevant and frequently cited studies (mean: 28 citations). Citation rate was confirmed using the Web of Science. Study designs are reviewed and weaknesses discussed.

RESULTS

Evidence is lacking to suggest static occlusal factors cause TMD.

CONCLUSIONS

Poor study designs have led to much of the controversy over whether occlusal factors (including orthodontics) 'cause' TMD. In order to provide an evidence-base for future clinical practice, suggestions to improve study designs are made.

Assessment of disk displacements of the temporomandibular joint

The aim of the present research was to evaluate disk displacements (DDs) of the temporomandibular joint (TMJ) among patients referred for magnetic resonance imaging (MRI) scans, and analyze the type and prevalence of DD, gender, age, side distribution, reciprocal clicking, presence of pain, range of mouth opening movement, and dental condition. The sample comprised 113 patients, 12-78 years old (the age average was 36.4 ± 13.5 years), 92 females and 21 males, who underwent MRI between July 2001 and December 2002. A Signa Horizon system (GE) MRI scanner was used at a magnetic field magnitude of 1.5 T with a bilateral radiofrequency surface coil (6.5 x 6.5 cm). Twenty-three (20.4%) patients were found to be normal, whereas 90 (79.7%) presented with DD. Anterior DD (61.1%) was the most common type of articular disk displacement. Males and females were equally affected (no statistically significant difference). We did not find a statistically significant association between DD and increased age. Bilateral DD (70%) was the most common DD occurrence. We found a statistically significant association between reciprocal clicking and anterior DD with reduction. We did not find a statistically significant association between DD and pain, be it articular or facial pain, otalgia or cephalgia. We found a statistically significant association between anterior DD without reduction and mouth opening limitation. With regard to oral condition, we did not find a statistically significant association between DD and loss of teeth.

MR imaging of the temporomandibular joint

Temporomandibular joint (TMJ) internal derangement is fairly prevalent in patients presenting with facial pain. MR imaging has become the primary modality for the assessment of the temporomandibular joint. A review of the normal anatomy and the key imaging findings of the different pathologic entities affecting this joint are presented. A reading algorithm to facilitate a systematic interpretation of the TMJ imaging study also is provided.

Association between mandibular retrognathia and TMJ disorders in adult females

OBJECTIVE

This study assesses the association between temporomandibular joint (TMJ) disorders and mandibular retrognathia.

METHODS

We conducted a case-control study among women, aged 18-70 years, recruited from Kaiser Permanente Northwest Division (KPNW, Portland, OR) and Group Health Cooperative of Puget Sound (GHC, Seattle, WA). Cases (N= 160) were women seeking treatment for TMJ disorders at KPNW and GHC clinics. Controls (N=151) were women without TMJ disorders, selected from among adult female dental hygiene patients at KPNW or GHC enrollees. Case status was determined by questionnaire; mandibular sagittal position (orthognathic, mildly retrognathic, severely retrognathic, or prognathic) was measured using digitized facial photographs. Odds ratios (OR) and associated 95 percent confidence intervals (CI) estimated the magnitude of the association between TMJ disorders and mandibular sagittal position.

RESULTS

Women with TMJ disorders were 4.0 times (95% CI=1.5, 10.8) more likely than controls to have severe retrognathia; no association with mild retrognathia or prognathia was seen. Results were similar when cases were restricted to those with recent onset of TMJ pain (OR=6.3; 95% CI=1.8, 21.8).

CONCLUSIONS

We found a strong association between TMJ disorders and severe mandibular retrognathia in adult females. In some women this likely resulted from TMJ disorders influencing mandibular development over time. However, among a subset of women, our data support the reverse hypothesis--that severe mandibular retrognathia may influence the development of TMJ disorders. Despite this strong association, abnormal mandibular position contributed only a small portion to the overall rate at which women sought treatment for TMJ disorders.

Detection and significance of the characteristic magnetic resonance signals of mandibular condyles in children

OBJECTIVE

We sought to determine the magnetic resonance imaging (MRI) characteristics of mandibular condyles in still-growing children. In addition, we also evaluated the significance of the double-contour-like structure and the conversion from red to yellow marrow characteristic of this age.

METHODS

The MRI characteristics of mandibular condyles were determined by means of fast spin-echo intermediate-weighted images in subjects 9 to 14 years old. In 1 subject who developed temporomandibular joint-related clinical symptoms 1 year later, MRI was re-performed at that time.

RESULTS

With the use of MRI, a total of 17 double-contour-like structures were detected in 42 temporomandibular joints of 9- to 14-year-olds, but neither 50 healthy joints of youths nor adults. In terms of bone marrow signal changes, the turning point was found to be 11 years old. In 1 subject, the double-contour-like structures were not visible on the MR images obtained 1 year after the first examination.

CONCLUSION

The double-contour-like structure and the periods of conversion from red to yellow marrow may be able to be used as part of the criteria for the staging of mandibular condyle development in children.

Evaluation of disc position in edentulous patients with complete dentures

OBJECTIVE

This study evaluated the condyle-disc relationship on magnetic resonance image (MRI) in a group of subjects with silent temporomandibular joints (TMJs) when tested clinically with those in subjects with discernible temporomandibular sounds. Study design Twenty-five completely edentulous patients were selected to participate in this study. The study was based on bilateral MRIs of 15 patients (with articular sound) and 10 symptom-free volunteers (control).

RESULTS

It was noted that disc displacement was found in 45% of the TMJs with no history of articular sounds. In 6 TMJs of control group, a reducing disc displacement was found, and in 3 TMJs a permanent displacement was found. Disc displacements were identified in 70% of patients. Reducing disc displacement was found in 19 of these TMJs, whereas permanent displacement was found in 2 TMJs. In 9 of the joints of the symptomatic group, a superior disc position was found. Also verified was a significant association between reducing disc displacement and biconvex disc.

CONCLUSION

These observations demonstrated that internal derangements can not be associated to clicking joints or symptoms of temporomandibular disorders in elderly edentulous patients, and the presence of displaced discs seems to be associated to altered disc morphology, but not to osseous abnormalities.

Evaluation of the relation between the horizontal condylar angle and the internal derangement of the TMJ - a magnetic resonance imaging study

This research aimed at assessing the relation between the horizontal condylar angle (HCA) and the internal derangement (ID) of the temporomandibular joint (TMJ), as a result of interference by the TMJ disk, in individuals undergoing magnetic resonance (MR) scans. The sample included a total of 144 TMJs (sagittal and coronal views) of 72 subjects, 15 of whom were male and 57 female, with ages ranging from 15 to 70. The scans were made in a Signa system (GE) model at a magnetic field magnitude of 1.5 T. Sixty-eight TMJs were found to be normal, while 46 showed anterior displacement with reduction. Of these, 41 had some kind of adaptive change in the condyle, while 5 showed degenerative changes. Anterior displacement without reduction was found in 29 joints, 12 of which showed adaptative changes in the condyle, while 17 showed degenerative changes. Only one posterior displacement of the articular disk was recorded. For the TMJs in which disk displacement was found, such values achieved 24.69º on the right side, and 22.94º on the left side. Hence, it was possible for us to conclude that the HCA tends to increase in those TMJs where ID is present. For contralateral TMJs, a strong association was observed between HCA values (57.8%), state of normality (69.7%), and ID (66.7%). To corroborate such findings, a correlation between contralateral HCA values (63.31%) and the diagnosis for contralateral TMJs (68.05%) was determined. Thus, we could infer that there is a tendency between contralateral TMJs to share characteristics and conditions.

[Do men and women have different perceptions of pain?]

OBJECTIVE

To evaluate possible differences between men and women's perception of a painful stimulus (venous puncture).

DESIGN

Transversal, analytic and observational study.Setting. Primary care.Participants. 709 people over 14 who attended three health centres for blood extraction. 98 cases were rejected (most because they received more than one puncture).

MAIN MEASUREMENTS

Age, sex, tobacco habit, perception of pain (through visual analogic scale from 1 to 10), complaints expressed (oral and/or by gestures) and patient's prior expectations.

RESULTS

Mean age: 47.4; 60.1% women. The intensity of pain had an average of 1.35 (SD, 1.60; mode, 0; median, 0.8). 14.7% expressed a complaint. Median of pain was 0.95 (Q3-Q1, 1.9-0.4) in men, whereas it was 0.70 (Q3-Q1, 1.725-0.3) in women (U=40.48; P=.095). No correlation was found between valuation of pain and age (R=0.055). No differences were found for smokers (median, 0.925; Q3-Q1, 1.725-0.35) or non-smokers (0.75; 1.825-0.325) (P.05). There were statistically significant valuations that varied according to the prior expectations of pain. Equally, pain was assessed as more intense by those who expressed a complaint (median, 2.1; Q3-Q1, 3.85-0.475) versus those who did not (0.625; 1.55-0.3) (P<.001).

CONCLUSIONS

We found no significant differences between men and women's perception of painful stimulus. In any case, differences were clinically irrelevant. There is wide individual variability, which suggests that the essential factors are psycho-social. We have to assess and treat properly a patient in pain, regardless of his/her gender.

MR imaging of the temporomandibular joint

Technologic advances in MR imaging have had a decisive effect on the capacity of investigators to image the TMJ. This article provides a description of the normal anatomy and function of this joint. emphasizing the key imaging findings of internal derangement. A reading algorithm is given to achieve a systematic approach to the interpretation of a temporomandibular MR imaging study. Finally, a summary of key imaging findings of other miscellaneous pathologic processes involving this joint is provided.

Prevalence of temporomandibular joint disk displacement in infants and young children

OBJECTIVE

The purpose of this study was to determine the prevalence of temporomandibular joint disk displacement in infants and young children.

STUDY DESIGN

Magnetic resonance images were obtained of the temporomandibular joints in 30 infants and young children ranging in age from 2 months to 5 years (median age, 3 years; mean age, 2.5 years).

RESULTS

All joints had normal superior disk position. The computed 95% confidence interval was 0.00-0.06, which implies a minimal probability that disk displacement would occur in this age group.

CONCLUSIONS

The result contradicts previous suggestions that temporomandibular joint disk displacement could represent a congenital normal anatomic variant.