Can the severity of orofacial myofunctional conditions interfere with the response of analgesia promoted by active or placebo low-level laser therapy?

OBJECTIVE: To analyze the influence of orofacial myofunctional condition (OMC) on pain perception, temporomandibular disorders (TMD) severity, and the response to low-level laser therapy (LLLT) in women with painful TMD. METHODS: Seventy-eight women, 59 with TMD, received active laser (30) or placebo (29), with 19 controls. OMC, TMD severity, pain intensity, and pressure pain threshold (PPT) were assessed at different times during the masticatory test: before treatment (LLLT dose: 780nm), during, and after 30 days. RESULTS: No correlation was found between OMC and pain perception or TMD severity (p > 0.05). The active and placebo LLLT showed reduction of pain during chewing and better recovery levels during the rest period (p > 0.05), without differences between OMC groups. DISCUSSION: The perception of pain and severity of TMD are not correlated with the OMC, and the response of analgesia promoted by active LLLT or placebo is not associated with OMC.

Ultra-low frequency transcutaneous electric nerve stimulation does not affect the centric relation registration.

OBJECTIVE: To evaluate the influence of ULF-TENS on the displacement of the mandibular condyle and on the repeatability of centric relation (CR) registration of three different techniques: bimanual manipulation (BM), long strip technique, and harmonic centric occlusal relationship (R.O.C.A. wires). METHODS: Twenty-five participants without temporomandibular disorder (TMD) underwent two study stages conducted via electronic position analysis: (1) three CR records were made, one for each manipulation technique; (2) the ULF-TENS was applied for 30 min, and after that the same CR records were repeated. STATISTICAL ANALYSES: Mann-Whitney, ICC, and one-tailed F test. RESULTS: The ULF-TENS did not influence the condyle total displacement, regardless of CR recording technique used (p > 0.05). BM showed an improvement in repeatability after ULF-TENS. DISCUSSION: Concerning the variance, BM showed less variation at the X-axis. Long strip technique and R.O.C.A. wires varied less at the Y-axis. Long strip technique was again less variable at the Z-axis.