Recapture of temporomandibular joint disks using anterior repositioning appliances: an MRI study

Recommendations on the Use of Oral Orthotic Occlusal Appliance Therapy for Temporomandibular Joint Disorders: Current Evidence and Clinical Practice

Background

'Temporomandibular joint disorders (TMDs)' denote an umbrella term that includes arthritic, musculoskeletal and neuromuscular conditions involving the temporomandibular joint, the masticatory muscles, and the associated tissues. Occlusal devices are one of the common treatment modalities utilized in the conservative management of TMDs. The indications for the available 'oral splints' or 'oral orthotic occlusal devices' remain ambiguous.

Methods

A joint international consortium was formulated involving the subject experts at TMJ Foundation, to resolve the current ambiguity regarding the use of oral orthotic occlusal appliance therapy for the temporomandibular joint disorders based on the current scientific and clinical evidence.

Results

The recommendations and the conclusion of the clinical experts of the joint international consort has been summarized for understanding the indications of the various available oral orthotic occlusal appliances and to aid in the future research on oral occlusal orthotics.

Conclusion

The use of the oral orthotic occlusal appliances should be based on the current available scientific evidence, rather than the archaic protocols.

Temporomandibular Joint Disk Displacement: Etiology, Diagnosis, Imaging, and Therapeutic Approaches

An estimated 8 to 15% of women, and 3 to 10% of men currently suffer from Temporomandibular disorders, and it has been reported that sounds are a common finding and have been observed in 28% to 50% of the adult population; sounds are almost always connected to "internal derangements" a condition in which the articular disk displaced from its position on the mandibular condyle. Due to the multifactorial etiology of temporomandibular joint dysfunction, any accurate diagnosis based on clinical examination alone often proves to be difficult, so a clinical examination should be utilized together with other imaging methods to determine the relationship between the disk and condyle before and after treatment. In general, management of temporomandibular joint-related conditions is necessary when pain or dysfunction is present, so many surgical or nonsurgical methods of treatment have been reported. The Occlusal splint is 1 of the most widespread treatment it induces a slight vertical condylar distraction and eliminates the occlusal factor, which can be responsible for Temporomandibular joint disturbances, removing the influence of the teeth on the joint position by the slight distraction of the joint which, in turn, enables damaged connective tissue to heal.

The effect of anterior repositioning splint therapy on maximum bite forces in patients with disc interference disorders

OBJECTIVE

To evaluate the effect of anterior repositioning splint (ARS) on maximum bite force (MBF) values in patients with disc interference disorders (DID).

MATERIAL AND METHODS

Twenty-two patients with disc interference disorders and 22 healthy subjects participated in to study. The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I have been used to diagnose DID patients. All patients received ARS therapy for 6 weeks. The MBF measurement was performed with Flexi-Force piezo-resistive sensors for both healthy subjects and patients before and after ARS therapy.

RESULTS

A significant difference was recorded by the increase of the mean MBF values after the use of the ARS in the patient with disc derangements (p < .05).

CONCLUSIONS

APS therapy is efficient for eliminating pain and increasing MBF of the patients with DID. In addition, the use of FlexiForce sensors may be a practical solution to assess the bite force in the clinical setting.

"RA.DI.CA." Splint for the Management of the Mandibular Functional Limitation: A Retrospective Study on Patients with Anterior Disc Displacement without Reduction

The study aimed at assessing the effectiveness of the RA.DI.CA. splint in the management of temporomandibular joint disc displacement without reduction (ADDwoR) and jaw functional limitation. The authors developed a retrospective clinical study. A total of 2739 medical records were screened. One hundred and forty-one patients with chronic unilateral disc displacement without reduction and jaw limitation, treated with a multifunctional RA.DI.CA. splint, were enrolled. Temporomandibular pain, headache, familiar pain, neck pain, and emotional strain, maximum spontaneous mouth opening, and lateral excursions were evaluated at baseline (T0), after therapy (T1), and during the follow-up (T2). Descriptive statistical analysis was performed. Wilcoxon test assessed changes in symptomatology and functional aspects before and after treatment and between T1 and T2, with p < 0.05. Ninety-nine patients (70%) declared themselves "healed" from jaw functional limitation with no residual painful symptoms, 31 (22%) improved their symptoms and jaw function, 11 (8%) reported no changes compared to T0 and no one worsened. As for all parameters analyzed, the comparison between the ones before and after treatment was statistically significant (p < 0.05). The RA.DI.CA. splint proved to be highly performing and promoting functional and symptomatologic recovery, also in the medium and long term, through the restoration of the functional disc-condyle relationship and the healing of joint tissues.

Can anterior repositioning splint effectively treat temporomandibular joint disc displacement?

The aim of this study was to determine whether anterior repositioning splint (ARS) can effectively treat temporomandibular joint (TMJ) anterior disc displacement with reduction (DDwR) in juvenile Class II patients. This study investigated disc repositioning clinically and through use of MRI with 12-month follow up. Patients with skeletal Class II malocclusions and DDwR diagnosed by magnetic resonance imaging (MRI) were treated with ARS. The efficacy of ARS was assessed clinically and by means of MRI before treatment (T0), immediately after bite registration (T1), at the end of treatment (T2), and at 12 months after functional appliance treatment (T3). Improvement in TMJ pain, TMJ noises, and range of mandibular movement were assessed. MRI evaluation was based on disc-condylar relationship in parasagittal images. Seventy-two juvenile patients with 91 joints were included in this study. The average age was 15.7 years old (range, 10–20 years) at first visit. There were statistically significant reductions in TMJ pain, disability in daily life and TMJ clicking (P < 0.01). MRI at T2 indicated that the success rate was 92.31% (84/91), but decreased to 72.53% (66/91) at T3. The unsuccessful splint disc capture was mainly observed in late adolescence, especially over 18 years old. Using MRI results as the gold standard, we found that clinical assessment had an accuracy rate of 75.82% at 12-month follow-up. In conclusion, although success rate for ARS treatment decreased over time, both clinical findings and MRI examination indicate that the ARS is relatively effective in repositioning the DDwR, especially for patients in early puberty. However, further and larger studies are needed to evaluate the outcome with ARS.

A Michigan-type occlusal splint with spring-loaded mandibular protrusion functionality for treatment of anterior disk dislocation with reduction

For treatment of temporomandibular disorders Michigan-type splints are frequently used, as are mandibular advancement appliances for patients diagnosed with anterior disk dislocation. As both types show good results, the combination of these two mechanisms into one bimaxillary appliance was tested on eight patients where splint therapy had brought reduction but not complete elimination of the symptoms. An existing maxillary Michigan splint was modified so that advancement springs could be fitted and the generated forces were transmitted to a mandibular retainer, which did not interfere with the function of the splint. Treatment progress was monitored with computerized axiography and in all cases the axiographic tracings after the bimaxillary treatment showed no pattern indicative of disk dislocation under normal jaw movements. Myofascial pain symptoms, already improved by the pre-treatment with the Michigan splint, were found to be reduced further or eliminated completely. The approach of retrofitting a Michigan splint with the springs allowed for a versatile appliance, which required no occlusal alteration to the finely adapted splint but could as easily be brought back to the simple splint-functionality either for daytime use or for a period of stabilization of the result after successful treatment. Compliance was found to be very good and the short treatment period, together with the small force levels did not produce any detectable dental side effects.

Joint intracapsular disorders: diagnostic and nonsurgical management considerations

This article reviews common intracapsular temporomandibular disorders encountered in the dental practice. It begins with a brief review of normal temporomandibular joint anatomy and function followed by a description of the common types of disorders known as internal derangements. The etiology, history, and clinical presentation of each are reviewed. Nonsurgical management is presented based on current long-term scientific evidence.

Limitation of the diagnostic value of MR images for diagnosing temporomandibular joint disorders

OBJECTIVES

Many studies have shown that MRI findings are reliable when experienced calibrated observers work as a group. The hypothesis was that MRI findings can be used as the gold standard also when evaluation is made by single expert observers.

STUDY DESIGN

Temporomandibular joint (TMJ) MRIs of 34 patients were evaluated independently by four reviewers with expert knowledge of radiology for the presence of 13 specified pathologic entities, as well as the quality of the images, on a 5-step scale from "Sure Yes" to "Sure No". Intraclass correlation coefficients were calculated to estimate the rating reliability of the examiners. A coefficient of at least 0.8 was deemed good, between 0.60 and 0.80 was deemed acceptable, and less than 0.60 was considered poor. Additionally, weighted kappa statistics were used for pair-wise comparisons across all four reviewers.

RESULTS

The hypothesis was not supported by the results. None of the 13 correlation coefficients for comparisons between single examiner evaluations of pathologic entities was good and 8 were poor.

CONCLUSION

A diagnosis of TMD based on MRI examination protocols made by a single examiner should not be accepted as a gold standard with regard to TMJ disorders.

Multifactorial comparison of disk displacement with and without reduction to normals according to temporomandibular joint hard tissue anatomic relationships

STATEMENT OF PROBLEM

There is disagreement about the predictive value of temporomandibular joint tomographic anatomy in the diagnosis of internal derangements.

PURPOSE

This study aimed to identify multifactorial temporomandibular hard tissue relationships that differentiate disk displacement with reduction and disk displacement without reduction from normals.

MATERIAL AND METHODS

Temporomandibular joint tomograms from females diagnosed with unilateral disk displacement with (n=84) or without (n=78) reduction were compared to 42 asymptomatic normal joints with the use of 14 linear and angular measurements and 8 ratios. A validated classification tree model was tested for accuracy with sensitivity, specificity, goodness of fit, and the amount of log likelihood accounted for. The tree model was compared with a multiple logistic regression model and univariate testing.

RESULTS

The disk displacement with reduction tree model consisted of 3 disease and 2 normal pathways with interactions between fossa width to depth ratio, condyle position, and linear posterior joint space. This class was characterized by either a much wider- and shallower-than-average fossa shape and/or by a moderately posterior condyle position when the fossa shape was average to deeper and/or narrower. The logistic regression and univariate models also suggested wider and/or shallower fossae, as well as longer eminence length. The disk displacement without reduction tree model consisted of 2 disease pathways and 1 normal pathway. Interactions characterized this class by either a posterior to very posterior condyle position or by a much deeper than average fossa depth when the condyle position was concentric to anterior. The logistic regression model emphasized greater fossa depth and width versus normals. The tree models conservatively predicted the disease classes: Rescaled Cox and Snell R(2) 37.0%, sensitivity 70.2%, and specificity 90.5% for disk displacement with reduction; R(2) 28.8%, sensitivity 66.7%, and specificity 85.7% for disk displacement without reduction.

CONCLUSION

Within the limitations of this study, hard tissue relationships revealed by central tomogram sections were able to model notable differences between disk displacement with reduction and disk displacement without reduction versus asymptomatic normals when temporomandibular joints were examined as a multifactorial system typified by interactions of fossa width to depth proportions and condyle position. While substantial, the hard tissue predicted only part of the biology. The model could be broadened by additional factors and interactions.

Oral splints: the crutches for temporomandibular disorders and bruxism?

Despite the extensive use of oral splints in the treatment of temporomandibular disorders (TMD) and bruxism, their mechanisms of action remain controversial Various hypotheses have been proposed to explain their apparent efficacy (i.e., true therapeutic value), including the repositioning of condyle and/or the articular disc, reduction in the electromyographic activity of the masticatory muscles, modification of the patient's "harmful" oral behavior, and changes in the patient's occlusion. Following a comprehensive review of the literature, it is concluded that any of these theories is either poor or inconsistent, while the issue of true efficacy for oral splints remains unsettled. However, the results of a controlled clinical trial lend support to the effectiveness (i.e., the patient's appreciation of the positive changes which are perceived to have occurred during the trial) of the stabilizing splint in the control of myofascial pain. In light of the data supporting their effectiveness but not their efficacy, oral splints should be used as an adjunct for pain management rather than a definitive treatment. For sleep bruxism, it is prudent to limit their use as a habit management aid and to prevent/limit dental damage potentially induced by the disorder. Future research should study the natural history and etiologies of TMD and bruxism, so that specific treatments for these disorders can be developed.