Current Evidence Providing Clarity in Management of Temporomandibular Disorders: Summary of a Systematic Review of Randomized Clinical Trials for Intra-oral Appliances and Occlusal Therapies

Effect of layer thickness and polishing on wear resistance of additively manufactured occlusal splints

OBJECTIVE

To evaluate the effect of polishing and layering thickness on the wear resistance of 3D-printed occlusal splint materials.

METHODS

Specimens with 3 different layer thicknesses (50, 75, 100 µm) were produced in the form of a disc 3 mm thick using V-Print splint resin on a 3D-printer with digital light processing technology. (n = 16 for each thickness) All specimens were washed and cured according to the manufacturer's instructions. Half of the specimens of each layer thickness were polished with silicon carbide papers. All specimens were subjected to 120.000 cycles of a chewing simulator for 2-body wear tests. Before and after the wear test, the specimens were scanned with a laser scanner, and the images were overlaid using a 3D analysis program and the volume loss was calculated. The wear patterns of the specimens were examined under a scanning electron microscope. Statistical evaluation was performed using a Shapiro-Wilk test, 2-way ANOVA, 1-way ANOVA, and Tukey post hoc test (α = 0.05).

RESULTS

While polishing had a significant effect (p = 0.003) on the wear volume of the occlusal splints, layer thickness (p = 0.105) and their interaction between polishing and layer thickness (p = 0.620) did not significantly affect the wear volume. Regardless of the polishing, the lowest mean wear was observed for D50 (0.064 mm3), followed by D75 (0.078 mm3), and D100 (0.096 mm3). However, a significant difference was observed only between polished D50 and unpolished D100.

CONCLUSION

The polished 3D-printed occlusal splint resin showed higher wear resistance than the unpolished one, regardless of the layer thickness.

CLINICAL SIGNIFICANCE

Since different layer thicknesses of 50 µm and greater had no effect on the wear resistance of the material, a layer thickness of 100 µm may be preferred for faster printing. However, polishing occlusal splints may reduce the amount of wear and improve clinical performance.

Clinical aspects of mastication myalgia-an overview

Mastication myalgia is the most common cause of non-odontogenic pain in the orofacial region and is often associated with a reduced quality of life. The purpose of this review is to provide an overview of the clinical aspects of myalgia based on available research. The review includes epidemiological, diagnostic, and etiological aspects. In addition, the potential risk factors related to the transition from acute to chronic myalgia are explored and treatment strategies are presented for its management. As a result, this review may increase clinical knowledge about mastication myalgia and clarify strategies regarding prevention, diagnostics, and management to improve prognosis and reduce patient suffering.

Temporomandibular Disorders and Dental Occlusion: What Do We Know so Far?

Throughout the recorded history in the literature of temporomandibular disorders (TMD) there have been a variety of opinions as to its primary cause. Those supporting an occlusal basis of TMD opined that occlusal dysfunction is either the primary cause for or a significant etiopathogenic factor in the causation of TMD. Most of the current literature, however, points to evidence in another direction and questions the causal role of occlusion and occlusal disharmony in TMD etiopathogenesis. Recognition of this evidence-based literature is paramount in eliminating and preventing the chances of overtreatment of patients with TMD.

Nonsurgical Management of Temporomandibular Joint Arthropathy

Arthropathy is a broad diagnostic term for any pathologic condition afflicting one or more joints of the body. Temporomandibular joint (TMJ) arthropathy is an umbrella term that may be applied to mechanical dysfunction or disease of one or both TMJs. This article provides evidence-based recommendations for conducting a patient evaluation, initiating a diagnostic workup, formulating an assessment, and instituting various nonsurgical modalities for the treatment of TMJ arthropathies.

Effectiveness of conservative therapeutic modalities for temporomandibular disorders-related pain: a systematic review

PURPOSE

The aim of this systematic review was to evaluate the effectiveness of conservative different therapeutic modalities for temporomandibular disorders (TMD) pain.

MATERIALS AND METHODS

An electronic systematic search was conducted in the MEDLINE (PubMed) database to identify the randomized clinical trials (RCTs) published between 2001 and 2021. The following, simple or multiple conjunctions, search keywords were selected: TMD pain, TMD management or conservative treatment or treatment strategies and TMD pain, therapeutic modalities or interventions and TMD. Studies included must have patients older than 18 years, with painful TMD, which diagnosis was performed by Research Diagnostic Criteria for TMD or Diagnostic Criteria for TMD. Outcome variables were pain relief and post treatment pain intensity reduction. Data were analysed with non-parametric tests and the level of significance was set at p<.05.

RESULTS

Out of 1599 articles obtained, 28 RCTs fulfilled all selection criteria and were included. The results of this study show that there was a significant decrease in short-term post-treatment TMD pain with the use of occlusal splint alone or in combination with other therapeutic modalities when compared with the control group. Statistically significant differences were also detected between laser and photobiomodulation group and the control, in short-term treatment TMD-related pain.

CONCLUSIONS

The primary findings of the present systematic review showed that the occlusal splint alone or combined with other therapeutic intervention presented positive effect on short-term TMD pain reduction. Secondary outcome suggests that laser and photobiomodulation therapy had, also, a significant role in short term pain relief.

Patients' perceptions on temporomandibular disorder treatment with hydrostatic oral splints - a pilot study

Objective

To evaluate temporomandibular disorder (TMD) treatment with a prefabricated, hydrostatic oral splint (HOS) based on self-reported patient’s symptoms using a standardized questionnaire.

Methods

Two hundred fifty-eight questionnaires from patients diagnosed with TMD and subsequently treated with HOS were collected from two independent private practices. Based on patient’s comfort the questionnaire recorded TMD symptoms and symptom regression. Descriptive and comparative statistics was carried out using SPSS.

Results

A total of 221 questionnaires were analyzed. Patients reported TMD symptoms such as pain (93.2%), TMJ clicking (66.1%), headache (25.8%), cervical spine disorders (23.5%), restricted mouth opening (22.6%) and tinnitus (11.8%). For most symptoms, improvement was reported mostly after two weeks, except for tinnitus, where positive effects were usually reported after four weeks.

Conclusion

HOS seem to be effective for immediate treatment of pain and other TMD symptoms. Based on the available data, a treatment period of four weeks can be recommended.

Wear Behavior of Occlusal Splint Materials Manufactured By Various Methods: A Systematic Review

PURPOSE

To systematically review studies on various materials and methods used for wear testing of occlusal devices and their antagonists in vitro and in vivo.

METHODS

An electronic search in OVID, Web of Science, PubMed and Scopus was conducted using the following terms (MeSH words) with any synonyms and closed terms: "Splint*" OR "occlusal splint*" OR "night guard" OR "occlusal device" OR "occlusal devices" OR "deprogrammer" OR "bite splint" OR "bite plane" OR "orthotic appliance*" OR "orthotic devices" AND "wear" OR "two-body wear" OR "three-body wear" OR "tooth wear" OR "wear measurement*" OR "wear behaviour" OR "wear behavior" OR "abrasion" AND "Polymethyl Methacrylate" OR "PMMA" OR "acrylic resin*" OR "dental material*" OR "dental enamel" OR "CAD" OR "CAM" OR "PEEK" OR "material* testing". Database search was limited to English-language publications and published between 2001 and 1st of September 2021. A further hand search was done to ensure all materials were captured.

RESULTS

After the removal of duplicates, 115 studies were identified, and 11 were chosen for review. Studies showed that the lowest volumetric loss was observed in PEEK occlusal device materials, whereas heat-cure, CAD-milled, and 3D printed occlusal device materials had no significant difference in wear. Vacuum-formed materials showed the highest wear among all groups. Testing parameters were found to be inconsistent across all studies.

CONCLUSION

There is a need for standardization of in vitro and in vivo wear measurement and testing protocols as this study revealed a wide variety of testing protocols which potentially could influence the outcome. Polishing procedures are required for the material. Limited studies are available on 3D printed occlusal device materials and would therefore require further investigation, especially on printing build angles and settings. Further clinical studies would be advantageous to provide guidance on the selection of the best occlusal device material that would last the longest without remake.

Temporomandibular disorders: a review of current concepts in aetiology, diagnosis and management

Temporomandibular disorders (TMD) is a collective term for a group of musculoskeletal conditions involving pain and/or dysfunction in the masticatory muscles, temporomandibular joints (TMJ) and associated structures. It is the most common type of non-odontogenic orofacial pain and patients can present with pain affecting the face/head, TMJ and or teeth, limitations in jaw movement, and sounds in the TMJ during jaw movements. Comorbid painful and non-painful conditions are also common among individuals with TMD. The diagnosis of TMD have significantly improved over time with the recent Diagnostic Criteria for TMD (DC/TMD) being reliable and valid for most common diagnoses, and an efficient way to communicate in multidisciplinary settings. This classification covers 12 most common TMD, including painful (myalgia, arthralgia and headache attributed to TMD) as well as the non-painful (disc displacements, degenerative joint disease and subluxation) TMD diagnoses. Recent studies have demonstrated that the pathophysiology of common painful TMD is biopsychosocial and multifactorial, where no one factor is responsible for its development. Importantly, research has suggested different predisposing, initiating and perpetuating factors, including both peripheral and central mechanisms. This is an active field of investigation and future studies will not only seek to clarify specific causal pathways but translate this knowledge into mechanism-directed diagnosis and treatment. In accordance with this complex aetiology, current evidence supports primarily conservative multidisciplinary treatment including self-management strategies, behavioural therapy, physical therapy and pharmacotherapy. The aim of this review is to present an overview of most recent developments in aetiology, pathophysiology, diagnosis and management of TMD.

Effcacy of Manual Therapy in TemporomandibularJoint Disorders and Its Medium-and Long-TermEffects on Pain and Maximum Mouth Opening:A Systematic Review and Meta-Analysis

The aim of this study was to conduct a systematic review of the medium- and long-term efficacy of manual therapy for temporomandibular joint disorders, alone or in combination with therapeutic exercise. Information was compiled from the PubMed, SCOPUS, Cochrane, SciELO and PEDro databases. The inclusion criteria were established: randomized controlled trials only; participants must present any kind of temporomandibular disorder; the treatments must include manual therapy in at least one of the experimental groups; a minimum of 3 months of follow-up; pain must be one of the primary or secondary outcomes; and the article must be available in English, Spanish, Italian, Portuguese or French. Six documents that fulfilled all the criteria were obtained for analysis, two of them considered low quality and four considered high quality. A significant improvement in pain and mouth opening compared to baseline was observed after manual therapy treatment. Manual therapy seems to be an effective treatment for temporomandibular disorders in the medium term, although the effect appears to decrease over time. However, when complemented with therapeutic exercise, these effects can be maintained in the long term. This review underlines the importance of manual therapy and therapeutic exercise for the medium- and long-term treatment of temporomandibular joint disorders in daily practice.

Occlusion and Temporomandibular Disorders: A Long-Standing Controversy in Dentistry

The relationship between temporomandibular disorders (TMDs) and occlusion remains controversial. Some authors believe that occlusion is the primary factor in the onset of TMD symptoms, whereas others feel that occlusion has no role in this at all. The majority of reasoning behind causation is based upon anecdotal rather than scientific evidence. Existing evidence in the literature supports the absence of a disease-specific association. This article describes this controversy and provides the reader with findings from contemporary literature.

Efficacy of splint therapy for the management of temporomandibular disorders: a meta-analysis

Temporomandibular disorders (TMD) are a group of clinical problems affecting temporomandibular joint (TMJ), myofascial muscles and other related structures. Splint therapy is the most commonly used approach to treatment of TMD, but its effectiveness is remains unclear. We therefore conducted a meta-analysis to evaluate the effectiveness of splint therapy for TMD in adults. The electronic databases PubMed, EMBASE, Cochrane Library, and ClinicalTrials.gov were searched for reports published up to March 31, 2016. Thirteen eligible studies involving 538 patients were identified. The results indicated that splint therapy increased maximal mouth opening (MMO) for patients with a MMO <45mm and reduced pain intensity measured using the visual analogue scale (VAS) for patients with TMD without specific description (TMDSD). Splint therapy also reduced the frequency of painful episodes for patients with TMJ clicking. No publication bias was observed, as determined with Egger's test for all outcomes. On the basis of this evidence, we recommend the use of splints for the treatment and control of TMD in adults.

Implications of Vertebrate Craniodental Evo-Devo for Human Oral Health

Highly processed diets eaten by postindustrial modern human populations coincide with higher frequencies of third molar impaction, malocclusion, and temporomandibular joint disorders that affect millions of people worldwide each year. Current treatments address symptoms, not causes, because the multifactorial etiologies of these three concerns mask which factors incline certain people to malocclusion, impaction, and/or joint issues. Deep scientific curiosity about the origins of jaws and dentitions continues to yield rich insights about the developmental genetic mechanisms that underpin healthy craniodental morphogenesis and integration. Mounting evidence from evolution and development (Evo-Devo) studies suggests that function is another mechanism important to healthy craniodental integration and fit. Starting as early as weaning, softer diets and thus lower bite forces appear to relax or disrupt integration of oral tissues, alter development and growth, and catalyze impaction, malocclusion, and jaw joint disorders. How developing oral tissues respond to bite forces remains poorly understood, but biomechanical feedback seems to alter balances of local bone resorption and deposition at the tooth-bone interface as well as affect tempos and amounts of facial outgrowth. Also, behavioral changes in jaw function and parafunction contribute to degeneration and pain in joint articular cartilages and masticatory muscles. The developmental genetic contribution to craniodental misfits and disorders is undeniable but still unclear; however, at present, human diet and jaw function remain important and much more actionable clinical targets. New Evo-Devo studies are needed to explain how function interfaces with craniodental phenotypic plasticity, variation, and evolvability to yield a spectrum of healthy and mismatched dentitions and jaws.

Counseling and oral splint for conservative treatment of temporomandibular dysfunction: preliminary study

Abstract Introduction Temporoamndiular Disorders (TMD) involve the masticatory muscles, temporomandibular joint (TMJ) or both. The most common symptom is pain, which is usually located in the muscles of mastication, pre-auricular region, and / or ATM, especially during mandibular function. The main treatment for TMD is related to pain relief. Objective The purpose of this case report was to evaluate the reduction of pain symptoms using Visual Analogue Scale (VAS) of patients with TMD treated with counseling and use of occlusal splint (OS). Material and method 16 subjects had participated in this study, that was composed by 4 appointment with 7-day interval between each (CEP FOP / Unicamp – 137/2009). In the first, an examiner used the Research Diagnostic Criteria for Temporomandibular Disorders (RDC / TMD) to diagnose each patient and delivered a VAS to register the intensity of daily pain. In the second, counseling, molding of both dental arcs to fabricate the OS and the delivery of new VAS were performed. In the third, there was the installation and adjustment of the OS and the delivery of another scale, and in the last, possible adjustments on the OS were done. Data were analyzed by ANOVA two way and Tukey post-test at 5% significance level. Result There was significant difference when comparing the intensity of pain of individuals after installation of splint with the baseline data and after counseling (p = 0.05). Conclusion According to the result of this study, the treatment of TMD associating counseling occlusal splint is effective in reducing pain intensity.

Comparison of three different options for immediate treatment of painful temporomandibular disorders: a randomized, controlled pilot trial

OBJECTIVE

The purpose of this study was to compare the short-term effectiveness of three different types of immediate, non-pharmacological intervention for alleviation of the painful symptoms of temporomandibular disorders (TMD).

MATERIAL AND METHODS

Thirty-six patients (mean age 41.6 ± 16.7 years, 25 females) diagnosed with non-dysfunctional painful TMD received counselling and subsequently were randomly allocated to three treatment groups: patients in Group A received prefabricated oral splints with water-filled elastic pads (Aqualizer(®)), those in Group B were provided with vacuum-formed co-polyester oral splints and those in Group C were given appointments to receive Michigan-type hard splints. Clinical examination was conducted, at baseline and after 2 weeks, by use of the RDC/TMD. Current pain intensity was determined by evaluation of graded chronic pain status (GCPS) on a numerical rating scale (NRS). Active maximum mouth opening without pain (AMMOP) was also measured. Paired sample t-tests and one-way analysis of variance with a significance level of p ≤ 0.05 were conducted.

RESULTS

After 2 weeks, overall mean current pain was reduced by 41.95% (p < 0.001). Current pain reduction was significant for Group B (66.6%, p < 0.001) but not for Groups A (37.88%, p = 0.56) and C (22.29%, p = 0.26). After 2 weeks, current pain level for Group B was significantly lower than that for Group C (p = 0.041). Overall, there was a statistically significant increase of AMMOP (p = 0.01).

CONCLUSION

All therapeutic options were pain-reducing. The results from this study suggest that cost-effective and time-effective intervention of counselling combined with use of a vacuum-formed splint is a favourable option for initial, short-term treatment of painful TMD.

The knowledge level of dental surgeons regarding the relationship between occlusal factors and Temporomandibular Disorders (TMD)

AbstractIntroductionThe relationship between dental occlusion and temporomandibular disorders (TMD) remains a subject of disagreement. Many professionals erroneously base diagnosis and treatment strictly on the occlusal factor, despite the fact that current scientific evidence does not show such a relationship.ObjectiveTo evaluate the knowledge of dental surgeons (DSs) from João Pessoa (PB)-Brazil, regarding the relationship between occlusal factors and TMD.Materials and methodA sample of 100 DSs who do not have expertise in TMD and orofacial pain (CG Group) and seven DSs with this specialty (EG Group) completed a questionnaire that addresses issues concerning knowledge of TMD and its relationship with occlusal factors. The questionnaire also contained information used to characterize the sample, such as age, gender, and length of experience. The current literature's degree of consensus was established as the "gold standard" response for each statement and was compared with the responses of the specialists and non-specialists. Data were tabulated using the SPSS software package and analyzed descriptively (by percentage) and statistically using the chi-square and Fisher's exact tests (p < 0.05).ResultA wide divergence could be observed between the knowledge of DSs who do not specialize in TMD and orofacial pain and that of professionals who do.ConclusionThere was low agreement between specialists and non-specialists. The relationship between dental occlusion and TMD remains unclear for the vast majority of participating professionals, which may prove to be reflected in diagnostic behaviors and inappropriate occlusal treatment for the management of TMD.

Systematic review and recommendations for nonodontogenic toothache

Nonodontogenic toothache is a painful condition that occurs in the absence of a clinically evident cause in the teeth or periodontal tissues. The purpose of this review is to improve the accuracy of diagnosis and the quality of dental treatment regarding nonodontogenic toothache. Electronic databases were searched to gather scientific evidence regarding related primary disorders and the management of nonodontogenic toothache. We evaluated the level of available evidence in scientific literature. There are a number of possible causes of nonodontogenic toothache and they should be treated. Nonodontogenic toothache can be categorised into eight groups according to primary disorders as follows: 1) myofascial pain referred to tooth/teeth, 2) neuropathic toothache, 3) idiopathic toothache, 4) neurovascular toothache, 5) sinus pain referred to tooth/teeth, 6) cardiac pain referred to tooth/teeth, 7) psychogenic toothache or toothache of psychosocial origin and 8) toothache caused by various other disorders. We concluded that unnecessary dental treatment should be avoided.

Evaluation of Glucosamine sulfate and Ibuprofen effects in patients with temporomandibular joint osteoarthritis symptom

OBJECTIVE

Ibuprofen - a non-steroidal anti-inflammatory drug (NSAID)- and glucosamine sulfate - a natural compound and a food supplement- are two therapeutic agents which have been widely used for treatment of patients with temporomandibular joint (TMJ) disorders. This study was aimed to compare the effectiveness and safety of these two medications in the treatment of patients suffering from TMJ disorders.

METHODS

After obtaining informed consent, 60 patients were randomly allocated to two groups. Patients with painful TMJ, TMJ crepitation or limitation of mouth opening entered the study. Exclusion criteria were history of depressive disorders, cardiovascular disease, musculoskeletal disorders, asthma, gastrointestinal problems, kidney or liver dysfunction or diabetes mellitus, dental diseases needing ongoing treatment; taking aspirin or warfarin, or concomitant treatment of TMJ disorder with other agents or methods. Thirty patients were treated with ibuprofen 400 mg twice a day, (mean age 27.12 ± 10.83 years) and 30 patients (mean age 26.60 ± 10) were treated with glucosamine sulfate 1500 mg daily. Patients were visited 30, 60 and 90 days after starting the treatment, pain and mandibular opening were checked and compared within and between two groups.

FINDINGS

Comparing with baseline measures, both groups had significantly improved post-treatment pain (P < 0.0001 for both groups) and mandibular opening (P value: 0.001 for glucosamine sulfate and 0.03 for ibuprofen). Post treatment pain and mandibular opening showed significantly more improvement in the glucosamine treated patients (P < 0.0001 and 0.01 respectively). Rate of adverse events was significantly lower in the P value glucosamine sulfate group (P < 0.0001).

CONCLUSION

This investigation demonstrated that comparing with a commonly prescribed NSAID - ibuprofen-, glucosamine sulfate is a more effective and safer therapeutic agent for treatment of patients with TMJ degenerative join disorder.

Efficacy of appliance therapy on temporomandibular disorder related facial pain and mandibular mobility: a randomized controlled study

There is limited evidence supporting the role of occlusal splints in Temporomandibular disorder (TMD) therapy. The aim of this randomized controlled clinical trial was to assess the efficacy of stabilization splint therapy on TMD related facial pain and mandibular mobility. The sample of study consisted of eighty consecutive patients diagnosed with TMD. Patients were randomly assigned into two groups: a splint group (n = 40) comprising of patients treated with stabilization splint, councelling and masticatory muscle exercises, and a control group (n = 40), comprising of patients treated with councelling and masticatory muscle exercises alone. Data from both the groups were collected at the beginning of the study and after a 6-month follow up. The outcome variables were visual analogue scale on facial pain intensity and clinical findings for TMD (anterior maximal opening, mandibular right laterotrusion, mandibular left laterotrusion, mandibular protrusion, and number of painful muscle sites). Changes within the splint and control groups (before treatment and 6 months after treatment) were analyzed using paired samples t test. Differences in change between the splint and control groups were analyzed using independent samples t-test. The level of significance was set at p < 0.05. Facial pain and number of painful muscle sites decreased, and the mandibular mobility increased significantly in both groups after treatment; however the differences in changes in VAS or clinical TMD findings between the two groups were not statistically significant. The findings of this study show that stabilization splint treatment in combination with counselling and masticatory muscle exercises has no additional benefit in relieving facial pain and increasing the mobility of the mandible than counselling and masticatory muscle exercises alone over a 6-months' time interval.

Efficacy of stabilisation splint treatment on temporomandibular disorders

The evidence supporting the use of stabilisation splints in the treatment of temporomandibular disorders (TMD) is scarce and a need for well-controlled studies exists. The aim of this randomised, controlled trial study was to assess the efficacy of stabilisation splint treatment on TMD. The sample consisted of 80 consecutive referred patients who were randomly assigned to the splint group (n = 39) and the control group (n = 41). Subjects in the splint group were treated with a stabilisation splint, whereas subjects in the control group did not receive any treatment except counselling and instructions for masticatory muscle exercises which were given also to the subjects in the splint group. Outcomes were visual analogue scale (VAS) on facial pain intensity and clinical findings for TMD which were measured at baseline and after 1-month follow-up. The differences in change between the groups were analysed using regression models. Facial pain decreased and most of the clinical TMD findings resolved in both of the groups. The differences in changes in VAS or clinical TMD findings between the groups were not statistically significant. The findings of this study did not show that stabilisation splint treatment in combination with counselling and masticatory muscle exercises has additional benefit in relieving facial pain and increasing the mobility of the mandible than counselling and masticatory muscle exercises alone in a short time-interval.

Sleep bruxism: a comprehensive overview for the dental clinician interested in sleep medicine

Sleep bruxism (SB) is a common sleep-related motor disorder characterized by tooth grinding and clenching. SB diagnosis is made on history of tooth grinding and confirmed by polysomnographic recording of electromyographic (EMG) episodes in the masseter and temporalis muscles. The typical EMG activity pattern in patients with SB is known as rhythmic masticatory muscle activity (RMMA). The authors observed that most RMMA episodes occur in association with sleep arousal and are preceded by physiologic activation of the central nervous and sympathetic cardiac systems. This article provides a comprehensive review of the cause, pathophysiology, assessment, and management of SB.

IMMPACT recommendations for clinical trials: opportunities for the RDC/TMD

The Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) recommendations for core domains and measures of outcome in clinical trials complement the parallel work completed on Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The overall approach of the RDC/TMD is consistent with the IMMPACT recommendations, although the specific tools used to quantify clinical presentation are appropriately different based on the precedents established in the TMD literature. The IMMPACT recommendations, while directed at clinical trials, have broad utility for all clinical research in TMD. Future TMD studies should consider including a measure of health-related quality of life and tracking participant disposition, as well as tracking adverse events from treatment and assessing the participant's global assessment of change in clinical trials. The RDC/TMD methodology provides a rich basis upon which to develop standards for quantifying the clinical significance of treatment outcomes across multiple domains, an area ripe for development. Axis II may benefit from a shift in conceptualisation in which measurement focuses on screening for depression and somatisation to a new, dimensional approach in which Axis II domains are measured and evaluated on a continuum of symptom severity. Combined with the expansion of Axis II to include measures of catastrophising and sleep disturbance, the resulting approach may provide a powerful method for evaluating risk profiles associated with poor outcomes in TMD.

Evaluation criteria for musculoskeletal and craniofacial tissue engineering constructs: a conference report

Over the past 20 years, tissue engineering (TE) has evolved into a thriving research and commercial development field. However, applying TE strategies to musculoskeletal (MSK) and craniofacial tissues has been particularly challenging since these tissues must also transmit loads during activities of daily living. To address this need, organizers invited a small group of bioengineers, surgeons, biologists, and material scientists from academia, industry, and government to participate in a two and half-day conference to develop general and tissue-specific criteria for evaluating new concepts and tissue-engineered constructs, including threshold values of success. Participants were assigned to four breakout groups representing commonly injured tissues, including tendon and ligament, articular cartilage, meniscus and temporomandibular joint, and bone and intervertebral disc. Working in multidisciplinary teams, participants first carefully defined one or two important unmet clinical needs for each tissue type, including current standards of care and the potential impact of TE solutions. The groups then sought to identify important parameters for evaluating repair outcomes in preclinical studies and to specify minimally acceptable values for these parameters. The importance of in vitro TE studies was then discussed in the context of these preclinical studies. Where data were not currently available from clinical, preclinical, or culture studies, the groups sought to identify important areas of preclinical research needed to speed the development process. This report summarizes the findings of the conference.

Do occlusal splints have an effect on complex regional pain syndrome? A randomized, controlled proof-of-concept trial

OBJECTIVES

Studies have suggested overlaps between various chronic pain conditions and painful temporomandibular disorders (TMDs). The objective of this pilot study was to assess the effectiveness of occlusal splint (OS) therapy on self-reported measures of pain in patients with chronic complex regional pain syndrome (CRPS) as compared with a nontreatment group.

METHODS

The design was a prospective randomized controlled clinical trial. Twenty patients with CRPS were randomly assigned to either the OS or control group. The patients in the OS group were asked to use the OS at nighttime and for 3 hours during daytime for a total of 7 weeks; the control group had no stomatognathic intervention. The primary outcome was self-reported assessment of CRPS-related pain on numerical rating scales. Secondary outcome measures were the Temporomandibular Index (TMI), and the Short Form 36 Health Survey (SF-36).

RESULTS

All patients had TMD signs and symptoms, but OS had no effect on CRPS-related pain on the numerical rating scale (P>0.100). The changes in the TMI scores over time were 16.6%+/-24.6% (improvement) in the OS group and -21.3%+/-25.9% (impairment) in the control group that was significant (P=0.004). There were no differences in the changes of SF-36 scores between groups (P=0.636).

DISCUSSION

The use of OS for 7 weeks has no impact on CRPS-related pain but improved signs and symptoms of TMD pain. Future studies should include an active control group and evaluate if long-term changes in measures of oral health impact general health in CRPS-related pain.

Risk factors for the occurrence and prevention of temporomandibular joint and muscle disorders: lessons from 2 recent studies

INTRODUCTION

Our objectives were to demonstrate how standard epidemiologic measurements can assist in evaluating the risk factors for tempormandibular joint and muscle disorders (TMJMD) and to determine whether prevention is feasible.

METHODS

We reviewed 2 recent studies that examined third-molar extractions and severe mandibular retrognathia as risk factors for TMJMD. Cumulative incidences were available from these studies. By using these values, standard epidemiologic measurements of risk, including population attributable risk (PAR), attributable risk (AR), population attributable risk percent (PAR%), and attributable risk percent (AR%), were calculated. (PAR and AR are reported as the numbers of cases per 10,000 per year.)

RESULTS

In the third-molar extraction study, PAR, AR, PAR%, and AR% were 5, 10, 25%, and 40%; in the severe mandibular retrognathia study, they were 0.5, 17.5, 10%, and 80%, respectively.

CONCLUSIONS

This review supports the current consensus that most risk factors explain only a small portion of TMJMD in the population. However, some factors might explain a significant portion of TMJMD in persons exposed to particular risk factors. This review supports the current consensus that prevention, by screening the population for risk factors and intervening, is probably not justified. Modification of certain risk factors among exposed persons to prevent TMJMD might be warranted. Incidence data and epidemiologic measurements of risk are needed to evaluate the importance of risk factors for the occurrence and prevention of TMJMD, in both the population and exposed persons.

The methodological quality of systematic reviews comparing temporomandibular joint disorder surgical and non-surgical treatment

BACKGROUND

Temporomandibular joint disorders (TMJD) are multifactor, complex clinical problems affecting approximately 60-70% of the general population, with considerable controversy about the most effective treatment. For example, reports claim success rates of 70% and 83% for non-surgical and surgical treatment, whereas other reports claim success rates of 40% to 70% for self-improvement without treatment. Therefore, the purpose of this study was to (1) identify systematic reviews comparing temporomandibular joint disorder surgical and non-surgical treatment, (2) evaluate their methodological quality, and (3) evaluate the evidence grade within the systematic reviews.

METHODS

A search strategy was developed and implemented for MEDLINE, Cochrane Library, LILACS, and Brazilian Dentistry Bibliography databases. Inclusion criteria were: systematic reviews (+/- meta-analysis) comparing surgical and non-surgical TMJD treatment, published in English, Spanish, Portuguese, Italian, or German between the years 1966 and 2007(up to July). Exclusion criteria were: in vitro or animal studies; narrative reviews or editorials or editorial letters; and articles published in other languages. Two investigators independently selected and evaluated systematic reviews. Three different instruments (AMSTAR, OQAQ and CASP) were used to evaluate methodological quality, and the results averaged. The GRADE instrument was used to evaluate the evidence grade within the reviews.

RESULTS

The search strategy identified 211 reports; of which 2 were systematic reviews meeting inclusion criteria. The first review met 23.5 +/- 6.0% and the second met 77.5 +/- 12.8% of the methodological quality criteria (mean +/- sd). In these systematic reviews between 9 and 15% of the trials were graded as high quality, and 2 and 8% of the total number of patients were involved in these studies.

CONCLUSION

The results indicate that in spite of the widespread impact of TMJD, and the multitude of potential interventions, clinicians have expended sparse attention to systematically implementing clinical trial methodology that would improve validity and reliability of outcome measures. With some 20 years of knowledge of evidence-based healthcare, the meager attention to these issues begins to raise ethical issues about TMJD trial conduct and clinical care.