Aims: To compare the difference in the quality of life between temporomandibular disorders (TMD) patients and non-TMD subjects diagnosed with the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) or the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD).
Methods: Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (EMBASE) and Latin American and Caribbean Health Sciences Literature (LILACS) databases were searched in studies published in English and Portuguese. The search was performed by two independent reviewers in duplicate. A manual search and the gray literature were also included. The inclusion criteria were clinical studies that used the RDC/TMD axis I and quality of life with standard questionnaires in young and middle-aged adult population (18-55 years). The data were analyzed quantitatively by combining the results in a meta-analysis using forest plots. The measure of effect used was the standardized mean difference (SMD) in depression levels. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the studies. The publication bias was assessed by funnel plots. The initial search included 806 articles without duplications.
Results: Twenty-four articles were included in the final systematic review. Of these, 9 were included in the meta-analysis, where it was shown a statistically significant in all axis I groups: (a) global TMD-groups I, II and III combined, N = 3829, SMD (95% CI) = 1.06 (0.65-1.51), p = 0.000; (b) group I-muscle disorders, N = 3,056, SMD (95% CI) = 0.82 (0.45-1.18), p = 0.000; (c) group II-disc displacements, N = 3,184, SMD (95% CI) = 0.59 (0.26-0.91), p = 0.000; and (d) group III-arthralgia/arthritis/arthrosis, N = 2781, SMD (95% CI) = 0.98 (0.59-1.36), p = 0.000. When compared to controls.
Conclusions: Quality of life is affected in all axis I TMD patients, especially in groups I and III with higher pain intensity and disability as compared to group II.
Keywords: Epidemiology; Meta-analysis; Quality of life; Systematic review; Temporomandibular joint disorders.