Effect of occlusal splint on interleukin 6, malondialdehyde and 8-hydroxydeoxyguanosine levels in the synovial fluid of patients with temporomandibular disorders

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.

Finite element analysis of various thickness occlusal stabilization splint therapy on unilateral temporomandibular joint anterior disc displacement without reduction

INTRODUCTION

Occlusal stabilization splint is the most common treatment modality for temporomandibular joint disorders, but the optimal thickness is still uncertain. This study investigated the effect of the occlusal splint with different thicknesses on the stress distribution of the temporomandibular joint.

METHODS

Cone-beam computed tomography and magnetic resonance images were used to reconstruct the maxillofacial and disc, and the unilateral anterior disc displacement without reduction was established manually as the basic model. Occlusal splint with 5 different thickness levels (2, 3, 4, 5, and 6 mm) was added to the basic model as the study models. The displacement and stress distribution of the disc were evaluated.

RESULTS

The maximum von Mises stress of the condylar cartilage was the largest on the affected side, whereas the maximum von Mises stress of the disc was the largest on the unaffected side. The disc stress on the affected side was mainly distributed on the posterior zone and the intermediate zone for the unaffected side. The maximum von Mises stress of the bilaminar region on the affected side was greater than the unaffected side. The stress of the disc and bilaminar region was the lowest on the affected side in the 2 mm model. The disc displacement on the affected side gradually increased, whereas, on the unaffected side, it fluctuated.

CONCLUSIONS

These results showed that occlusal stabilization splint could decrease the stress of disc and bilaminar region, and 2 mm was considered the optimal thickness for the treatment of unilateral temporomandibular joint anterior disc displacement without reduction.

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.

LncRNA PVT1 induces chondrocyte apoptosis through upregulation of TNF-α in synoviocytes by sponging miR-211-3p

Temporomandibular joint osteoarthritis (TMJ OA) is an important subtype of temporomandibular disorders (TMD). Articular cartilage destruction is considered a common pathological feature of TMJ OA, which is reported to be mainly induced by chondrocyte apoptosis. Synovial sterile inflammation is an initial factor of TMJ OA-associated articular cartilage destruction. Therefore, determining the mechanism of synovial membrane inflammation-induced articular cartilage destruction in TMJ OA is important for the TMJ OA therapy. In this study, we detected the function of synoviocytes in chondrocyte apoptosis under lipopolysaccharide (LPS)-induced inflammatory conditions and explored the underlying mechanism. We found that synoviocytes in inflammatory conditions facilitated LPS-induced chondrocytes apoptosis by secreting increased Tumor Necrosis Factor α (TNF-α), which was induced by long non-coding RNA plasmacytoma variant translocation 1 (PVT1) upregulation. PVT1 served as a competing endogenous RNA that sponged the microRNA miR-211-3p and prevented the inhibition of TNF-α expression. In conclusion, our in vitro study revealed that PVT1 has a previously unknown role in chondrocyte apoptosis, which may also be a mechanism underlying synoviocyte involvement in TMJ OA.