Effectiveness of anterior repositioning splint versus other occlusal splints in the management of temporomandibular joint disc displacement with reduction: A meta-analysis

Abstract

Background:

Disc displacement with reduction (DDwR) is among the common disc disorders of temporomandibular joint (TMJ), which can be managed conservatively by splint therapy. Anterior repositioning splint (ARS) is the most commonly prescribed splint by dental practitioners, but not getting a normal disc–condyle relationship always and other side effects lead to need of comparing with other occlusal splints. This review will help in informed decision-making by clinicians in choosing an appropriate splint type for patients.

Aim:

The aim is to compare the effectiveness of ARS in the management of DDwR with other occlusal splints for TMJ and muscle pain, TMJ noise, any adverse effects, regaining normal disc–condyle relationship.

Materials and Methods:

We followed published protocol in the International prospective register of systematic reviews. Databases were searched till May 2023 using different search strategies as per the database. Title and abstract screening, followed by full-text screening and data extraction with risk of bias, was done by two independent reviewers in Covidence. Outcomes were reported as risk ratio (RR) or mean difference (MD) for dichotomous or continuous outcomes, respectively, using RevMan 5.4 (Review Manager 5.4) software. We used a random effect model for statistical analysis. Certainty of evidence was assessed using the Grading of Recommendation, Assessment, Development, and Evaluation Guideline Development Tool (GRADEpro GDT) software.

Results:

A total of 1145 reports were found from a database search. After screening, four studies were included for systematic reviews. Other occlusal splints reported were sagittal vertical extrusion device and mandibular ARS, full hard stabilization splint of canine or centric stabilization type. Data of only two studies could be used for meta-analysis having 30 participants received ARS and 40 received other occlusal splints. We did not find evidence of any difference between ARS and other occlusal splints for TMJ clicking in short term (RR 1.25, 95% confidence interval [CI] 0.91-1.72) but a small difference in favor of other occlusal splint in long term (RR 2.40, 95% CI 1.04–5.55). No evidence of any difference was found between both treatments for TMJ pain in short term (MD-5.68, 95% CI-17.31–5.95) and long term (MD 0.00, 95% CI-2.86–2.86) and muscle pain in short term. The certainty of evidence for comparison of two treatments for different outcomes was of low or very low level.

Conclusion:

Evidence is uncertain that other occlusal splints reduced TMJ clicking slightly in comparison to ARS. For the remaining outcomes, no evidence of any difference was found between the two splints and it may be biased due to selection bias, inadequate blinding of participants, and outcome assessor.

INTRODUCTION

The temporomandibular joint (TMJ) consists of the condyle, glenoid fossa, articular disc, and associated musculature and ligaments. The articular disc is present between the condyle and glenoid fossa, which helps in rotation and sliding movement smoothly. Temporomandibular disorders (TMDs) were broadly categorized into intra-articular and extra-articular disorders.[1] Disc displacement with reduction (DDwR) is one of the common TMDs.[2,3,4] Due to various reasons, the articular disc during the closing of the mouth is displaced from its position, but it takes its original position during the opening of the mouth.[5,6] This disorder is known as DDwR. After disc reduction during the translation of condyle, limitation in jaw opening is not found, but the movement of the mandible may not be as smooth as before.[6] The main clinical finding of DDwR is TMJ noise,[7] clicking being the most common complaint of the patient[8] and the main reason for seeking treatment. Muscle and joint pain may also be associated with it. Optimal treatment for DDwR is of great clinical significance for dental specialists and has been classified as conservative and nonconservative (invasive). Among the conservative treatments, splint therapy is a commonly administered treatment modality. The objective of the management of TMD with splint therapy is to help in achieving a normal relationship of the glenoid fossa with the condyle having the articular disc at the correct position. This may help in the reduction of TMJ joint pain and noise and improve mandibular function.[9] Among the wide variety of splints, anterior repositioning splint (ARS) is a commonly prescribed and used splint for DDwR.[10,11,12,13] ARS allows the recapture of the disc, that is, it enables the repositioning of the mandibular condyle back onto the disc. It helps in the alleviation of joint noises and pain by helping the anterior position of the mandible rather than maximal intercuspation.[14] However, indiscriminate long-term use of ARS can lead to irreversible changes in occlusion (posterior open bite) and rise in pain in the muscle (due to the protrusive position).[15,16] Studies have also reported reduced success rates in regaining of normal relationship of disc with condyle for long term.[11,17,18,19,20,21] However, all available clinical evidence needs to be taken into consideration to draw a conclusion regarding the use of ARS in the treatment of DDwR. Furthermore, the problems associated with the long-term use of ARS mandates the need for assessment of other occlusal appliances in the treatment of DDwR and to compare their effectiveness with ARS.

With this background, we aimed to assess the clinical effectiveness of ARS in treating symptoms of DDwR when compared with other occlusal appliances. Furthermore, evidence has to be generated regarding its success in regaining the normal condyle-to-disc relationship and any treatment adverse effects. Thus, findings from the systematic review may help clinicians discuss the choice of splint with informed decision-making by patients with adequate justification for the proposed treatment plan in a particular clinical situation.

METHODOLOGY

Protocol was registered in PROSPERO (Registration number CRD42020176000)[22] and is reported as per “Preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines.”[23]

The research question for systematic review was “In patients diagnosed with DDwR, is ARS more effective compared with other occlusal appliances in reducing TMJ noise, muscle pain, joint pain, and does it have any adverse effect?”

Population, Intervention, Comparison, Outcome (PICO) format for the systematic review was used to prepare search strategy for different databases:

1. Type of Population (P): Patients of any age, gender in which diagnosis of DDwR was made using research diagnostic criteria for TMDs or American Academy of Orofacial Pain,[24] or diagnostic criteria for TMDs[25]

   • Presence of bilateral or unilateral clicking, popping, and/or snapping sounds in TMJ detected with palpation during various mandibular movements

   • Presence of bilateral or unilateral pain in the TMJ region.

2. Intervention (I): ARS

3. Comparator (C): Other splints (OS) such as hard stabilization splint, soft stabilization splint, etc

4. Types of outcome measures (O): TMJ pain, TMJ noise, muscle pain, adverse effects, if any

5. Types of studies: Randomized controlled trials, quasi-randomized trials, or cross-over trials (first-period data were taken).

Exclusion criteria

1. Patients with congenital abnormalities and concomitant inflammatory or neoplastic conditions of TMJ, referred pain to TMJ due to other diseases, recent history of acute injury or any surgical treatment of TMJ and any form of therapy (including counseling, medication) administered concomitantly with splints. These patients were excluded as the inclusion of multiple conditions may have led to an invalid comparison

2. Studies that compare different types of intervention groups, studies that evaluate the effectiveness of splints after an initial active therapeutic intervention or concomitantly with other therapeutic interventions, reporting of data after definitive occlusal therapy, case reports, case series, reviews, conference proceedings, and abstracts.

Search strategy for databases and process of study selection

Three databases (Cochrane central register of Controlled Trials [CENTRAL], Medline [via PubMed], and Embase) were searched till May 2023 without any restriction on language and year of publication.

For each database, a comprehensive search strategy was developed for the identification of potentially eligible studies using various Boolean operators like “AND” or “OR” or “NOT.” Reviewer (BPS) conducted the search using different search strategies devised for different databases [Supplementary File 1]. The pool of retrieved articles was then transferred to reference management software (EndNote X9) to remove duplicates. After removing duplicates, articles were imported to Covidence for screening based on title and abstract initially, followed by full text by two independent reviewers (KM and BPS).[26] Any difference of opinion or conflicts that arose between the two reviewers was resolved by discussion with other reviewers (RS and BT).

Data extraction and assessment of the risk of bias

Data extraction and risk of bias (RoB) assessment (using RoB 1.0 tool) were done in covidence by two reviewers (KM and BPS) independently in accordance with the Cochrane Handbook for systematic reviews of interventions.[26] Any disagreements between the two reviewers was resolved by the third reviewer (RS).

Data extraction form was prepared and was checked for one definitely included study, one possibly included study, and one definitely nonincluded study. One reviewer modified the data extraction form and re-checked it. The form included the following details of each included study.

1. Identification of study: Study setting, country, sponsors, if any, publication details, E-mail of corresponding author

2. Method of study: Study design, objective, duration, ethical approval, null hypothesis, method of participant recruitment, follow-up, etc

3. Participants in the study: Inclusion and exclusion criteria, a diagnostic method used for DDwR, any baseline difference between groups, number of participants randomized, withdrawals or exclusion of participants with reasons

4. Intervention and comparison details of the study: Number of participants in intervention and comparison arm, type and details of intervention/comparator, follow-up, etc

5. Outcome included TMJ pain, TMJ noise, muscle pain, and adverse effects if any. The outcomes were divided as short term if follow-up was 3 months or less and long term if follow-up was more than 3 months.

Assessment of RoB was judged by RoB tool (RoB 1.0) after full-text screening.[26] The tool comprised seven domains: Random sequence generation, allocation concealment, blinding of participants, blinding of outcome assessor, incomplete outcome data, selective outcome reporting, and any other RoB. All domains were judged by two reviewers independently as low or unclear or high RoB with supporting annotation.

If any study required more information or clarification, one reviewer (KM) contacted the corresponding author of the study twice with a gap of 15 days if not responded by first E-mail. We judged unclear RoB for the concern domain if we did not get any response from the corresponding author. Cohen's Kappa (ĸ), measured through Covidence, to assess inter-rater reliability between the two reviewers, was found to be 0.84956. This indicates very good agreement between the reviewers KM and BPS.

Data analysis

Data were imported from Covidence to RevMan 5.4 for analysis.[27] We used a random-effects model to obtain a forest plot. Heterogeneity was assessed using I² statistic. If the I² value was more than 50%, then it was considered substantial heterogeneity. Grading of Recommendations, assessment, development, and evaluation (GRADE) was done by GRADE pro software (GRADEPro GDT 2022).[28,29]

RESULTS

A total of 1145 articles were retrieved upon searching the electronic databases till May 2023. Five hundred and thirty-nine duplicate articles were removed. Eighteen studies were excluded after full-text screening; wrong comparator (4), wrong intervention (5), wrong study design (1), wrong patient population (2), definition not as per protocol, (3) wrong outcome measure (1) and ongoing study (2).[30,31] Four[12,32,33,34] studies were included for systematic review after the screening stage. In these studies, ARS was compared with; canine-protected splint,[12] sagittal vertical extrusion device (SVED) and mandibular anterior repositioning splint (MORA),[32] and centric stabilization splint[33,34] and soft splints.[33] Table 1 presents the characteristics of the included studies. Eraslan et al.[34] and Fayed et al.[12] fulfilled all inclusion criteria, but data were not available in the form to be extracted and therefore could not be taken in meta-analysis. Hence, the meta-analysis was done for the remaining two studies with the available outcomes.[32,33] Figure 1 shows study flow diagram for the selection of studies as per PRISMA guidelines.

Table 1.

Basic characteristics of included studies

Study ID	Study design	Population	Sample size		Intervention ARS	Comparison Other	Outcome	Follow up period
			ARS	Other
Tecco, 2006[32]	RCT	Disc displacement with reduction 28 males and 22 females 28.8 (14–63) years	20	20	Anterior repositioning splint: Acrylic ramp in the anterior palatal area, mandibular anterior teeth contact with the protrusive guiding ramp	MORA worn during daytime, SVED was worn at night MORA: Acrylic covers the occlusal and lingual surfaces of the mandibular posterior teeth, from the canines to the most distal molar bilaterally SVED: Anterior ramp is constructed behind the canine area and engages the anterior mandibular teeth, preventing mandibular movement in a posterior direction	TMJ pain TMJ clicking Muscle pain	3 months, 6 months
Fayed, 2004[12]	RCT	Disc displacement with reduction 18–30 years	7	7	The anterior ramp of the ARS was developed into a smooth sliding surface. The ARS was adjusted to allow contacts on all the teeth, evenly and simultaneously, in the established advanced position	The CPS was adjusted to permit even centric occlusion contacts. In lateral excursions, the CPS provided canine rise	TMJ clicking	3 months
Devi, 2017[33]	RCT	Disc displacement with reduction 18–55 years	10	20	ARS was given	Centric stabilization splint (n=10) Soft splint was given (n=10)	TMJ pain TMJ clicking	10 weeks
Eraslan, 2021[34]	RCT	Disc displacement with reduction 18–60 years	20	20	ARS made of acrylic resin was given	Stabilization splint made of autopolymerizing acrylic resin was prepared and given	TMJ clicking	3 months

RCT: Randomized controlled trial, TMJ: Temporo-mandibular joint, CPS: Canine protected splint, SVED: Sagittal vertical extrusion device, MORA: Mandibular anterior repositioning splint, ARS: Anterior repositioning splint

Figure 1.

Preferred reporting items for systematic reviews and meta-analyses flow diagram

The quality of included studies was represented by RoB graph and summary in Figures 2 and 3, respectively. We judged 25% of studies[32] with low RoB and 75% with unclear RoB for sequence generation.[12,33,34] Kolmogorov–Smirnov test[32] was used for sequencing of data. In most of the studies, the method of sequence generation was not mentioned.[12,33] All studies were judged as unclear RoB for allocation concealment due to a lack of sufficient details about this domain. For blinding of participants and personnel, 25%[32] of studies judged at low RoB as it mentioned double blind, 50%[33,34] judged at unclear RoB as it did not mention blinding, and 25%[12] of the studies judged at high RoB as pain may have been subjectively experienced by the participants due to knowledge of intervention and also personnel delivering treatment could not be blinded. For blinding of outcome assessor, 25%[12] of studies were judged at low risk as the examiner was unaware of the treatment group and 75%[32,33,34] studies were judged at unclear RoB as no mention of outcome assessors was made. For incomplete outcome data, 75%[32,33,34] of studies were judged at low risk because outcome data of all participants was mentioned and 25%[12] of studies were judged at high RoB as lost to follow-up without reason was found. For selective outcome reporting, 100% of studies judged at unclear RoB as none of the studies were registered in an open-source database. Certainty of evidence was judged to prepare a summary of the finding table to inform-decision-making by dental practitioners using GRADE guidelines.

Figure 2.

Risk of bias graph

Figure 3.

Risk of bias summary

GRADE assessment showed very low or low certainty of evidence on comparison of ARS with other occlusal splints for different outcomes. The review quality was downgraded by one/two levels based on indirectness, inconsistency, limitation of study design, RoB, and imprecision [Table 2]. The random-effects model was used as there might be heterogeneity in regard to the usage of splints in different age, sex, and race groups and in different arches. Dichotomous and continuous data were measured using risk ratio (RR) and mean difference (MD), respectively. 30 participants treated with ARS, 10 in Devi 2017[33] and 20 in Tecco 2006.[32] No evidence of any difference in TMJ clicking between ARS and OS in short term (RR 1.25, 95% confidence interval [CI] 0.91 - 1.72, P = 0.17, I² = 0%, two studies; 60 participants), but evidence of a small difference was found in favor of OS in long term (RR 2.40, 95% CI 1.04–5.55, P = 0.04, one study; 40 participants) [Figure 4]. No evidence of any difference was found when ARS was compared to OS in DDwR for TMJ pain in short term (MD -2.15, 95% confidence interval [CI] -13.21-8.91, P = 0.70, I² = 54%, two studies; 60 participants) and long term (MD 0.00, 95% CI-2.86–2.86, P = 1.00, one study; 40 participants) [Figure 5]. There was no evidence of any difference in muscle pain between ARS and OS in short term (RR 1.25, 95% CI 0.63–2.50, one study; 40 participants) [Figure 6].

Table 2.

Summary of findings table of anterior repositioning splint versus other splints in the treatment of disc displacement with reduction using grading of recommendations, assessment, development, and evaluation approach

Patient or population: [Individuals with disc displacement with reduction] Setting: Hospital Intervention: [Anterior repositioning splint] Comparison: [Other splints]
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	No of participants (studies)	Certainty of the evidence (GRADE)
	Risk with [Other splints]	Risk with [Anterior repositioning splint]
TMJ clicking short term	633 per 1,000	792 per 1,000 (576 to 1,000)	RR 1.25 (0.91 to 1.72)	60 (2 RCTs)	⨁⨁◯◯ Lowb,c
TMJ clicking long term	250 per 1,000	600 per 1,000 (260 to 1,000)	RR 2.40 (1.04 to 5.55)	40 (1 RCT)	⨁⨁◯◯ Lowb,c
TMJ pain short term	The mean TMJ pain short term was 0	MD 2.51 lower (13.21 lower to 8.91 higher)	-	60 (2 RCTs)	⨁◯◯◯ Very lowa,b,c
TMJ pain long term	The mean TMJ pain long term was 0	MD 0 (2.86 lower to 2.86 higher)	-	40 (1 RCT)	⨁⨁◯◯ Lowb,c
Muscle pain short term	450 per 1,000	563 per 1,000 (284 to 1,000)	RR 1.25 (0.63 to 2.50)	40 (1 RCT)	⨁⨁◯◯ Lowb,c

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; MD: Mean difference; RR: Risk ratio. Explanations: a. downgraded by one level for serious inconsistency as I2 is>30%; b. downgraded by one level for serious risk of bias as there are unclear risk of bias; c. downgraded by one level for serious imprecision as optimal information size is less; GRADE: Grading of Recommendations, Assessment, Development, and Evaluation, RCTs: Randomized Controlled Trial, TMJ: Temporomandibular Joint. GRADE Working Group grades of evidence. High certainty: we are very confident that the true effect lies close to that of the estimate of the effect; Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different; Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect; Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

Figure 4.

Forest plot comparison between anterior repositioning splint and other splint for tempero-mandibular joint (TMJ) noise (as TMJ clicking). TMJ: Tempero-mandibular joint, ARS: Anterior repositioning splint, OS: Other splint, CI: Confidence interval

Figure 5.

Forest plot comparison between anterior repositioning splint and other splint group for TMJ pain. SD: Standard deviation, IV: Intravenous, CI: Confidence interval, TMJ: Tempero-mandibular joint

Figure 6.

Forest plot comparison between ARS and OS for Muscle pain. IV: Intravenous, CI: Confidence interval

DISCUSSION

The purpose of this review was to compare the clinical effectiveness of ARS with other occlusal appliances in treating symptoms of DDwR. The other occlusal splints (OS group) in the present systematic review were canine protected splint (CPS), stabilization splint, SVED, and MORA.

The outcomes taken into consideration were TMJ pain, muscle pain, TMJ noise, and adverse effects; however, we could not report on adverse effects as none of the included studies had reported regarding the same. In Devi et al.,[33] 10 participants of ARS were compared with both 10 participants of centric stabilization splint and 10 participants of soft splint, as shown in Figures 4 and 5.

TMJ clicking is one of the common symptoms related to DDwR. The stiffness of elevator muscles causing TMJ clicking can be functionally recovered by removing the discrepancy between centric relation and maximum intercuspation.[35] The results showed small evidence in favor of other splints when compared to ARS. This result is not in accordance with that reported by Al-Moraissi et al.[36] where ARS lowered the incidence of clicking (moderate quality evidence) when compared to stabilization splint. It is possible that this difference, favoring OS group, may have resulted from reduced joint noises caused by expanding the TMJ space, allowing smooth translation of the condyle beyond disc surface inhomogeneity and positional aberrations to create a functional equilibrium within the stomatognathic system,[37] or from achieving uniform contacts on all teeth with disocclusion of posteriors, which relaxes the elevator muscles resulting in reduced muscle tension.[38]

Furthermore, in a study where joints were taken as units instead of patients, in the ARS group, the symptom of TMJ clicking got resolved in four out of five pretreatment joints compared to seven out of eight pretreatment joints in the CPS group.[12] Occlusal splint therapy therefore helped to reduce TMJ clicking; however, it did not favor either of the two groups.

When TMJ pain in short term and long term was compared between ARS and OS, we found no evidence of any difference. The result is not in accordance with that reported in the meta-analysis by Al-Moraissi et al.[36] where ARS was found to be an effective treatment for arthrogenous TMD, but the quality of evidence was low.

This difference may be because ARS has been shown to reduce TMJ pain for anterior disc displacement by either reassembling the condyle anteriorly to recapture the displaced articular disc[39,40] or by moving the anteriorly displaced articular disc backward in the therapeutic lower jaw position to restore normal disc condyle relation.[41] Although uncommon, disc displacement could occur in directions other than the anterior, such as lateral, medial, or posterior.[42] Hence, even the use of OS can help with TMJ pain relief by increasing occlusal stability, relaxing the muscles, deprogramming the mandibular posture, and changing the vertical dimension.[43]

Muscle pain is the other common symptom of DDwR. On comparison of muscle pain between ARS and OS, the results did not find evidence of any difference. The result was not in accordance with Al-Moraissi et al.[36] where they found that a hard stabilization splint (OS) achieved better results in myogenous TMD patients. This difference could be because of similar outcomes produced by all occlusal splints, such as relaxation of muscles by impeding parafunctional habits, protecting the teeth and jaws, normalization of periodontal ligament proprioception, change in jaw joint space and redistribution of condylar shear forces[44,45]

Certainty of evidence using GRADE assessment showed low or very low quality of evidence because of downgrading the level of evidence. The reasons for downgrading the level of evidence were limitation in study design because sequence generation and blinding were not done adequately; inconsistency due to a high level of heterogeneity but reasons could not be explored due to a smaller number of studies; imprecision due to small sample size and wide CI crosses the line of no difference; indirectness due to various levels of protrusion used in fabricating anterior repositioning appliance.

None of the included studies were registered in the clinical trials registry, indicating bias in selective outcome reporting. As this might cause a negative impact on the quality of evidence generated, it is recommended that clinical trial registration should be emphasized and made mandatory for future clinical trials.

The differences observed between ARS and other occlusal splints in terms of TMJ pain, clicking, and muscle pain might be attributed to variations in the main objective of utilizing different splints in each study, the subjective assessment of Visual Analog Scale scale, which may vary from patient to patient, and variations in the method of evaluation of TMJ clicking.

This systematic review includes a methodical technique and an extensive, transparent search strategy. We performed independent and duplicate eligibility evaluation and data extraction. Our emphasis was on patient-centred outcomes and we presented a summary of the finding table for certainty of evidence for chosen outcomes.

Limitations of the review

The current analysis has several limitations; (1) Due to language and database restrictions, less number of studies could be included in the review, (2) Exclusion, inclusion criteria, duration, and type of TMD varied among studies, so pooling of data could not be done for all studies, (3) Due to nonavailability of individual patient data, aggregate data were analyzed, impeding an in-depth analyses.

Future research

Randomized controlled trials, prospectively registered in an open-source database and conducted using an unbiased systematic approach, will be helpful in improving the quality of evidence on the topic under consideration.

CONCLUSION

Based on the findings from the present review, it can be concluded that OS showed a small difference in favor of ARS for TMJ clicking in patients with DDwR. For TMJ pain and muscle pain, no evidence of any difference was found between ARS and OS. Overall, we found insufficient evidence to judge that ARS is better than other occlusal appliances for the management of DDwR.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

SUPPLEMENTARY FILE

Supplementary file 1

Embase search strategy: “jaw disease”/exp OR “jaw disease” OR “jaw pain”/exp OR “jaw pain” OR “temporomandibular joint disorder”/exp OR “temporomandibular joint disorder” OR “dislocation”/exp OR dislocation OR “face pain”/exp OR “face pain” OR “arthralgia”/exp OR arthralgia OR “myofascial pain”/exp OR “myofascial pain” OR “sound”/exp OR sound OR “tinnitus”/exp OR tinnitus) AND (“mandibular advancement device”/exp OR “mandibular advancement device” OR “occlusal splint”/exp OR “occlusal splint.”

PubMed search strategy: (((((((temporomandibular joint [MeSH Terms]) OR (craniomandibular disorders [MeSH Terms])) OR (((((((temporomandibular [Title/Abstract]) OR (temporo-mandibular [Title/Abstract])) OR (craniomandibular [Title/Abstract])) OR (cranio mandibular [Title/Abstract])) OR (jaw)) OR (mandib*)) OR ((((tmj) OR (tmd)) OR (cmj)) OR (cmd)))) AND ((joint dislocations [MeSH Terms]) OR ((disc (displace * OR derange * OR dislocat * OR reduc*)) OR (disk (displace * OR derange * OR dislocat * OR reduc*))))) OR ((((temporomandibular joint [MeSH Terms]) OR (craniomandibular disorders [MeSH Terms])) OR (((((((temporomandibular [Title/Abstract]) OR (temporo-mandibular [Title/Abstract])) OR (craniomandibular [Title/Abstract])) OR (cranio mandibular [Title/Abstract])) OR (jaw)) OR (mandib*)) OR ((((tmj) OR (tmd)) OR (cmj)) OR (cmd)))) AND (((facial pain [MeSH Terms]) OR (arthralgia [MeSH Terms])) OR ((((“face pain”) OR (“orofacial pain”)) OR (“myofascial pain”)) OR (“joint pain”))))) OR ((((temporomandibular joint [MeSH Terms]) OR (craniomandibular disorders [MeSH Terms])) OR (((((((temporomandibular [Title/Abstract]) OR (temporo-mandibular [Title/Abstract])) OR (craniomandibular [Title/Abstract])) OR (cranio mandibular [Title/Abstract])) OR (jaw)) OR (mandib*)) OR ((((tmj) OR (tmd)) OR (cmj)) OR (cmd)))) AND (((sound [MeSH Terms]) OR (tinnitus [MeSH Terms])) OR (clicking tinnitus)))) AND ((occlusal splints [MeSH Terms]) OR (((((((“oral splint*”) OR (“oral appliance*”)) OR (“occlusal appliance*”)) OR (“splint therapy”)) OR (“dental splint*”)) OR (“mandibular advancement splint*”)) OR (“mandibular advancement device*”)))) AND (((((((((randomized controlled trial [pt]) OR (controlled clinical trial [pt])) OR (randomized [tiab])) OR (placebo [tiab])) OR (drug therapy [sh])) OR (randomly [tiab])) OR (trial [tiab])) OR (groups [tiab])) NOT ((animals [mh]) NOT (humans [mh]))) Filters: English.

Central search strategy:

ID Search Hits.

#15 (“temporomandibular disorder”): Ti, ab, kw OR (TMJ disorder): Ti, ab, kw OR (TMD): Ti, ab, kw OR (disc displacement with reduction): Ti, ab, kw OR (arthralgia): Ti, ab, kw (Word variations have been searched) 7895.

#16 (occlusal splint): Ti, ab, kw (Word variations have been searched) 607.

#17 (anterior repositioning splint): Ti, ab, kw OR (ARS): Ti, ab, kw OR (splint): Ti, ab, kw OR (repositioning appliance): Ti, ab, kw (Word variations have been searched) 7819.

#18 (tmj pain): Ti, ab, kw OR (joint pain): Ti, ab, kw OR (muscle pain): Ti, ab, kw OR (tmj noise): Ti, ab, kw OR (TMJ clicking): Ti, ab, kw (Word variations have been searched) 41135.

#19 #15 AND #16 AND #17 AND #18 236.