Systematic Review Trends in TMD Management – an Umbrella Review

Objectives: The management of patients with Temporomandibular Disorders (TMD) is challenging for clinicians. Numerous treatment modalities have been proposed, and plenty of systematic reviews (SR) have been published on this topic. The aim of this umbrella review was to summarize the current evidence provided by SR on TMD management.
Methods: The protocol was registered on PROSPERO (CRD42021276856). Four electronic databases were explored in September 2021: PubMed (NLM), Scopus (Elsiever), Lilacs (VHL), Cochrane (Wiley). SR were considered eligible if they included a diagnosis of TMD, in adult and adolescent populations. Title and abstract screening and full-text assessment were performed by two independent reviewers. Included SR were grouped by treatment modality. The counting of primary studies included in each SR and of overlapping of primary studies was performed, and bibliometric data were extrapolated via Web of Sciences only for SR presenting with a DOI number.
Results: After duplicates were removed, 1,267 references were reviewed. Following title and abstract screening, 284 studies were included for full-text assessment, and 178 were finally included in the current umbrella review. The main reason for exclusion was not fulfilling the criteria for a SR. Most commonly evaluated treatment modalities were pharmacological treatment, followed by self-management/exercise. The degree of overlap in primary studies ranged between 1 and 18, with a mean value of 2.3. Ten (10) SR that specifically evaluated the effects of botulinum toxin injection in TMD management had a considerable overlap (>50%) of the included primary studies. One hundred thirty-two (132) SR underwent bibliographic analysis, pointing out an increasing trend in the number of published and cited SR annually, with a peak in 2020 (26 SR).
Conclusions: The number of SR on the management of TMD is continuing to increase. For some treatment modalities, there is a large overlap in primary studies, limiting the additional value of individual reviews.