Evaluation of low-level laser therapy in patients with acute and chronic temporomandibular disorders.

ABSTRACT

The purpose of this study was to address the following question among patients with acute or chronic temporomandibular disorders (TMD), does low-level laser therapy (LLLT) reduce pain intensity and improve maximal mouth opening? The sample comprised myogenic TMD patients (according Research Diagnostic Criteria for TMD). Inclusion criteria were male/female, no age limit, orofacial pain, tender points, limited jaw movements and chewing difficulties. Patients with other TMD subtypes or associated musculoskeletal/rheumatologic disease, missing incisors teeth, LLLT contra-indication, and previous TMD treatment were excluded. According to disease duration, patients were allocated into two groups, acute (<6 months) and chronic TMD (≥ 6 months). For each patient, 12 LLLT sessions were performed (gallium-aluminum-arsenide; λ = 830 nm, P = 40 mW, CW, ED = 8 J/cm(2)). Pain intensity was recorded using a 10-cm visual analog scale and maximal mouth opening using a digital ruler (both recorded before/after LLLT). The investigators were previously calibrated and blinded to the groups (double-blind study) and level of significance was 5% (p < 0.05). Fifty-eight patients met all criteria, 32 (acute TMD), and 26 (chronic TMD). Both groups had a significant pain intensity reduction and maximal mouth opening improvement after LLLT (Wilcoxon test, p < 0.001). Between the groups, acute TMD patient had a more significant pain intensity reduction (Mann-Whitney test, p = 0.002) and a more significant maximal mouth opening improvement (Mann-Whitney test, p = 0.011). Low-level laser therapy can be considered as an alternative physical modality or supplementary approach for management of acute and chronic myogenic temporomandibular disorder; however, patients with acute disease are likely to have a better outcome.