Quantification of disc displacement in internal derangement of the temporomandibular joint using magnetic resonance imaging

MRI changes and clinical characteristics in temporomandibular joints with displacement of the articular disk without reduction - a cross-sectional observational study

OBJECTIVES

This study examined changes in magnetic resonance imaging (MRI) of temporomandibular joints (TMJ) with anterior displacement disk without reduction (DDwoR) and its correlation to clinical symptoms.

METHODS

190 individuals with DDwoR were evaluated according to Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and MRI. Pain's chronicity/intensity and limited mouth opening (locking) were correlated with: TMJ degeneration (MRI T1), effusion (T2), disc's shape and position (proton density).

RESULTS

In 103 TMJ with DDwoR, hemiconvex shape (41.6%), sclerosis (45.6%) and mild effusion (47.6%) were the most prevalent findings. There was not association (p > .05) between: different DDwoR positions with pain's intensity/chronicity; effusion with locking. Disk deformation was associated with degeneration (p = .034) and pain's intensity (p = .006). Locking was associated with degeneration (p = .05).

CONCLUSIONS

Condylar osteodegeneration is often related to DDwoR. Locking by DDwoR is associated with severe levels of chronic pain and articular disk deformation.

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.

Assessment of anterior positioning splint in conjunction with lateral pterygoid BTX injection to treat TMJ disc displacement with reduction - a preliminary report

Objective

Treatment of temporomandibular disc displacement with reduction is controversial. This study assesses the use of an anterior positioning splint with botulinum toxin in the lateral pterygoid muscle (BTX) for such cases.

Methods

Twelve joints were included; groups I and II received BTX injection while group II also received an anterior positioning splint. Pain scores and clicking status were recorded at regular intervals then a postoperative MRI was done after 4 months.

Results

Clinical improvement was noted in both groups. Mean pain scores dropped significantly and clicks in the twelve joints disappeared in 83% of group I and 33% of group II. MRIs showed significant disc position improvement with the higher mean change (1.33 ± 0.76) in group I.

Group I showed better improvement of discal position and only one joint regained a click. Patients of group II reported discomfort from the splint which may have caused psychological distress and so worst pain scores.

Conclusions

Group I  showed slightly better results but the cost of BTX injections and the complications of the splint should be kept in mind and the decision of treatment selection made according to each condition.

[Morphometric features of the temporomandibular joints according to MR studies in adult patients with dislocations of the articular discs and malocclusion of the anterior teeth]

THE PURPOSE OF THE STUDY

To study the morphological features of the temporomandibular joints (TMJ) according to MR studies in adult patients with impaired occlusion of the anterior teeth and dislocations of the articular discs.

MATERIAL AND METHODS

The clinical study included 51 patients aged 17 to 47 years (mean age 28.12±7.44 years): 14 men and 37 women. On the basis of a clinical examination and MR findings of TMJ in 30 patients (mean age 26.77±7.48 years; 8 men and 22 women), TMJ dysfunction in the form of dislocation of articular discs was confirmed. In 21 patients (mean age 30.05±7.12; 15 women, 6 men), TMJ dysfunction without dislocation of articular discs was confirmed. The patients measured the value of vertical incisive overlap (overbite). Analyzing data from MR studies of TMJ, we measured the following values of both TMJs of each patient: the depth and transverse size of the articular fossa, the height of the articular tubercles and the transverse size of the head of the lower jaw.

RESULTS

The examined patients with joint dislocations of TMJ had morphological features: statistically significantly deeper and narrower articular fossae, higher articular tubercles and narrower in the sagittal plane of the head of the lower jaw compared to TMJ of patients with dysfunction without dislocation of articular disks. In addition, in patients with articular disk dislocations, a statistically significant (<0.05) increase in vertical incisal overlap was noted.

CONCLUSION

.TMJ in patients with dysfunction in the form of dislocations of articular discs had morphological features that allowed them to be classified as type 3.

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.

Radiological follow-up results of untreated anterior disc displacement without reduction in adults

The aim of this study was to assess the radiographic changes in untreated adults with bilateral anterior disc displacement without reduction. A cohort study was designed to compare the bone changes, effusion, disc configuration, and pseudo-disc changes on two magnetic resonance images obtained at least 24 months apart. Twenty-eight patients (22 female, six male) with a mean age of 33.1 years (range 20-57 years) were included. The mean interval between the initial visit and the follow-up visit was 36.2 months. At the initial visit, the frequencies of bone changes, effusion, disc deformation, and pseudo-disc changes were 51.79%, 35.71%, 100%, and 0%, respectively. At follow-up, the frequency of effusion had decreased significantly. The frequency of bone changes had increased significantly to 75%, but newly formed cortical bone was present in five condyles. All discs remained deformed. Pseudo-disc changes were detected in five joints. Over a long period of observation, there was a significant decrease in effusion and a significant increase in bone changes. However, some adaptive changes occurred.

Is anterior disc displacement without reduction associated with temporomandibular joint condylar height in juvenile patients younger than 20 years?

PURPOSE

Because disc displacement might be accompanied by degenerative changes in the condyle, this study explored the association between condylar height and anterior disc displacement without reduction in juvenile patients.

MATERIALS AND METHODS

This was a retrospective cohort study that enrolled a sample of patients younger than 20 years with unilateral disc displacement without reduction. All patients had 2 magnetic resonance imaging records taken from January 2010 to June 2013 (interval, >6 months). Condylar height, disc length, and displacement distance were measured. The predictor variable was joint status (healthy vs affected side), and the outcome variables were changes in condylar height, displacement distance, and disc length over time. SAS 9.13 was used for analysis and the P value was set at .05.

RESULTS

One hundred twenty-four patients (101 female and 23 male; mean age, 16.4 yr; mean interval, 13.6 months) were included. During the interval, the condylar height of the healthy side increased 0.75 mm, whereas the condylar height of the affected side decreased 0.41 mm. The disc of the affected side was shortened and more anteriorly displaced.

CONCLUSION

Anterior disc displacement without reduction could be accompanied by a decrease in condylar height in juvenile patients, and the disc might be shortened and more anteriorly displaced.

Posteroanterior cephalometric changes in subjects with temporomandibular joint disorders

OBJECTIVES

The aim of the study was to establish the changes in posteroanterior cephalometric variables in subjects with temporomandibular joint disorders (TMDs).

METHODS

Posteroanterior cephalograms of 61 subjects (age range 16-36.6 years, standard deviation 4.88 years) were used to determine cephalometric differences. Subjects were classified according to the Research Diagnostic Criteria for Temporomandibular Joint Disorders into three groups: unilateral TMD, bilateral TMD and no TMD. 14 linear and angular measurements were assessed on the posteroanterior cephalogram. For assessing facial asymmetry, the asymmetry index for bilateral measurements was calculated between the right and the left side. In cases with unilateral TMD, the asymmetry index was calculated using the difference between the unaffected and affected side. The differences among multiple groups were analysed using the one-way analysis of variance test and Scheffé post hoc test.

RESULTS

47 subjects were females (77%) and 14 were males (23%). 19 subjects had unilateral TMDs and 16 subjects had bilateral TMDs. The asymmetry index of the distance from the horizontal plane to the antegonion was higher in subjects with unilateral TMD than in patients with bilateral or no TMD (p < 0.05). Also, the asymmetry index of the distances from the vertical plane to the condyle (p = 0.05), gonion (Go) (p = 0.0004), antegonion (p = 0.002) and chin (Ch) (p = 0.02) was higher in subjects with unilateral TMDs. The asymmetry index of the O point-Go-Go' and O point-Ch-Ch' angles differed significantly in subjects with unilateral TMDs (p < 0.05).

CONCLUSIONS

Unilateral TMDs are associated with changes in posteroanterior cephalometric measurements. The assessment of posteroanterior cephalometric variables could be used as a key factor for evaluating the presence of TMDs.