Friday, July 30, 2010

Systematic Review and Meta-analysis of Randomized Controlled Trials Evaluating Intraoral Orthopedic Appliances for Temporomandibular Disorders

James Fricton, DDS, MS/John O. Look, DDS, PhD/Edward Wright, DDS, MS/Francisco G. P. Alencar, Jr, DDS, MS/Hong Chen, DDS, MS/Maureen Lang, DDS, MS/Wei Ouyang, DDS, PhD/Ana Miriam Velly, DDS, PhD. J OROFAC PAIN 2010;24:237–254.

Aims: To conduct a systematic review with meta-analysis of randomized controlled trials (RCTs) that have assessed the efficacy of intraoral orthopedic appliances to reduce pain in patients with temporomandibular disorders affecting muscle and joint (TMJD) compared to subjects receiving placebo control, no treatment, or other treatments. Methods: A search strategy of MEDLINE, the Cochrane Library, the Cochrane CENTRAL Register, and manual search identified all English language publications of RCTs for intraoral appliance treatment of TMJD pain during the years of January 1966 to March 2006. Two additional studies from 2006 were added during the review process. Selection criteria included RCTs assessing the efficacy of hard and soft stabilization appliances, anterior positioning appliances, anterior bite appliances, and other appliance types for TMJD pain. Pain relief outcome measures were used in the meta-analyses, and the QUORUM criteria for data abstraction were used. A quality analysis of the methods of each RCT was conducted using the CONSORT criteria. The review findings were expressed both as a qualitative review and, where possible, as a mathematical synthesis using meta-analysis of results. Results: A total of 47 publications citing 44 RCTs with 2,218 subjects were included. Ten RCTs were included in two meta-analyses. In the first meta-analysis of seven studies with 385 patients, a hard stabilization appliance was found to improve TMJD pain compared to non-occluding appliance. The overall odds ratio (OR) of 2.46 was statistically significant (P = .001), with a 95% confidence interval of 1.56 to 3.67. In the second meta-analysis of three studies including 216 patients, a hard stabilization appliance was found to improve TMJD pain compared to no-treatment controls. The overall OR of 2.15 was positive but not statistically significant, with a 95% confidence interval of 0.80 to 5.75. The quality (0 to 1) of the studies was moderate, with a mean of 55% of quality criteria being met, suggesting some susceptibility to systematic bias may have existed. Conclusion: Hard stabilization appliances, when adjusted properly, have good evidence of modest efficacy in the treatment of TMJD pain compared to non-occluding appliances and no treatment. Other types of appliances, including soft stabilization appliances, anterior positioning appliances, and anterior bite appliances, have some RCT evidence of efficacy in reducing TMJD pain. However, the potential for adverse events with these appliances is higher and suggests the need for close monitoring in their use.

Thursday, July 22, 2010

Is Occlusion A Primary Cause to TMD?

A Multiple Logistic Regression Analysis of the Risk and Relative Odds of Temporomandibular Disorders as a Function of Common Occlusal Features

A.G. Pullinger (Section of Orofacial Pain and Occlusion, UCLA, School of Dentistry, 10833 Le Conte Avenue, Los Angeles, California 90024-1668), D.A. Seligman (Section of Orofacial Pain and Occlusion, UCLA, School of Dentistry, 10833 Le Conte Avenue, Los Angeles, California 90024-1668), J.A. Gornbein (UCLA Department of Biomathematics, Los Angeles, California 90024). Journal of Dental Research.

A multiple logistic regression analysis was used to compute the odds ratios for 11 common occlusal features for asymptomatic controls (n = 147) us. five temporomandibular disorder groups: Disc Displacement with Reduction (n = 81), Disc Displacement without Reduction (n = 48), Osteoarthrosis with Disc Displacement History (n = 75), Primary Osteoarthrosis (n = 85), and Myalgia Only (n = 124). Features that did not contribute included: retruded contact position (RCP) to intercuspal position (ICP) occlusal slides < 2 mm, slide asymmetry, unilateral RCP contacts, deep overbite, minimal overjet, dental midline discrepancies, ≤ 4 missing teeth, and maxillo-mandibular first molar relationship or cross-arch asymmetry. Groupings of a minimum of two to at most five occlusal variables contributed to the TMD patient groups. Significant increases in risk occurred selectively with anterior open bite (p < 0.01), unilateral maxillary lingual crossbite (p < 0.05 to p < 0.01), overjets > 6-7 mm (p < 0.05 to p < 0.01), ≥5-6 missing posterior teeth (p < 0.05 to p < 0.01), and RCP-ICP slides > 2 mm (p < 0.05 to p < 0.01). While the contribution of occlusion to the disease groups was not zero, most of the variation in each disease population was not explained by occlusal parameters. Thus, occlusion cannot be considered the unique or dominant factor in defining TMD populations. Certain features such as anterior open bite in osteoarthrosis patients were considered to be a consequence of rather than etiological factors for the disorder.

By Karen McCloy, DDS


Occlusion is the act of the teeth coming together.

A primary cause is a factor that if present will reliably initiate the pathological changes that lead to tmd in a patient that did not previously have tmd.

TMD is a state of chronic pain in the tmj and the soft tissues supporting it. Chronic pain implies the presence of neural plasticity, so we are talking about a state of central sensitization involving the trigeminal nerve. There is no rule that says that tmd patients may not have similar changes in other areas of the central nervous system. Saying that someone has chronic pain does not address it's etiology, and someone with a clicking joint does not have tmd unless they have pain.

If you ask me is occlusion an important pain producing factor in patients with tmd the answer is a definite yes. In normal patients, without plastic changes, occclusal dsiharmony may be nociceptive, but that means it is not pain. Once there are neural changes it becomes pain, a form of allodynia where a nonpainful stimulus causes pain, like when you have a headache and touching your skin or brushing your hair hurts, and controlling it is key to calming down that nervous system.

But our treatment has multiple modes of action, besides occlusion.

It has a placebo effect, becasue we believe, and because of that our patients believe they will improve. Plus the decision to seek treatment also changes someones mindset and makes them more in control.

Our orthotics are a form of CBT.. cognitive behavioral therapy. We inserrt them and say lips together teeth apart, and the plastic reminds the patient what the correct oral posture is.

Orthotics provide an occlusal effect, because they provide stable and even point occlusion around the arch.

Orthotics have an orthopedic effect because the realign the mandible to the cranial base and cervical structures.

So we are back to Larry's the chicken or the egg. We only see the pain patients, and in them pain is correlated with occlusion, but that is not the same thing as causation. Our 1st study on nonpain patients showed that most of them had some form of occlusal issue, but they did not have pain. So I think something else has to happen.