Marcelo Oliveira Mazzetto

Low Intensity Laser Application in Temporomandibular Disorders: A Phase I Double-Blind Study

Abstract The purpose of this study was to evaluate the effectiveness of low intensity laser therapy (LILT) for the control of pain from temporomandibular disorder (TMD) in a random and double-blind research design. Forty-eight (48) patients presenting temporomandibular joint (TMJ) pain were divided into an experimental group (GI) and a placebo group (GII). The sample was submitted to the treatment with infrared laser (780 nm, 70 mW, 10 s, 89.7 J/cm2) applied in continuous mode on the affected temporomandibular region, at one point: inside the external auditive duct toward the retrodiskal region, twice a week, for four weeks. For the control group, two identical probes (one active and one that does not emit radiation) were used unknown by the clinician and the subjects. A tip planned for laser acupuncture was used and connected to the active point of the probe. The parameter evaluated was the intensity of pain after palpation of the condylar lateral pole, pre-auricular region and external auditive duct, according to the Visual Analogue Scale (VAS). Four evaluations were performed: Ev1 (before laser application), Ev2 (after 4th application), Ev3 (after 8th application) and Ev4 (30 days after the last application). Data were submitted to statistical analysis. The results showed a decrease in the pain level mainly for the active probe. Among the evaluations, the Ev3 exhibited lower sensitivity to palpation. In conclusion, the results show that low intensity laser is an effective therapy for the pain control of subjects with TMD.

Low Level Laser Effects On Pain to Palpation and Electromyographic Activity in TMD Patients: A Double-Blind, Randomized, Placebo-Controlled Study

Abstract The purpose of this study was to evaluate the effect of diode laser (GaAlAs – 780 nm) on pain to palpation and electromyographic (EMG) activity of the masseter and anterior temporalis muscles. The laser was applied on the temporalis and masseter muscles twice a week (four weeks). Forty-eight (48) patients with myofascial pain were randomly assigned between actual and placebo treatments and between the energetic doses of 25 J/cm2 and 60 J/cm2, and were evaluated using VAS before, immediately after the final application, and 30 days after the laser treatment. Surface electromyography was performed with maximum dental clenching before and after laser therapy. The results show there were no significant statistical differences in the EMG activity between the groups before and after laser treatment. With regard to the pain at palpation, although both groups presented a significant difference in the symptoms before and after the treatment, only the active doses showed statistically significant reductions in pain level in all the regions of the palpated muscles. However, there was no significant statistical difference between groups (experimental and placebo). In conclusion, low level laser did not promote any changes in EMG activity. The treatment did, however, lessen the pain symptoms in the experimental groups.

Low intensity laser therapy in temporomandibular disorder: a phase II double-blind study.

Abstract The purpose of this study was to evaluate the analgesic effect of Low Intensity Laser Therapy (LILT) and its influence on masticatory efficiency in patients with temporomandibular dysfunction (TMD). This study was performed using a random, placebo-controlled, and double-blind research design. Fourteen patients were selected and divided into two groups (active and placebo). Infrared laser (780 nm, 70 mw, 60s, 105J/cm2) was applied precisely and continuously into five points of the temporomandibular joint (TMJ) area: lateral point (LP), superior point (SP), anterior point (AP), posterior point (PP), and posterior-inferior point (PIP) of the condylar position. This was performed twice per week, for a total of eight sessions. To ensure a double-blind study, two identical probes supplied by the manufacturer were used: one for the active laser and one for the inactive placebo laser. They were marked with different letters (A and B) by a clinician who did not perform the applications. A Visual Analogue Scale (VAS) and a colorimetric capsule method were employed. Data were obtained three times: before treatment (Ev1), shortly after the eighth session (Ev2), and 30 days after the first application (Ev3). Statistical tests revealed significant differences at one percent (1%) likelihood, which implies that superiority of the active group offered considerable TMJ pain improvement. Both groups presented similar masticatory behavior, and no statistical differences were found. With regard to the evaluation session, Ev2 presented the lowest symptoms and highest masticatory efficiency throughout therapy. Therefore, low intensity laser application is effective in reducing TMD symptoms, and has influence over masticatory efficiency [Ev2 (0.2423) and Ev3 (0.2043), observed in the interaction Evaluations x Probes for effective dosage].

Measurements of jaw movements and TMJ pain intensity in patients treated with GaAlAs laser

The aim of this study was to evaluate the effectiveness of low-level laser therapy (LLLT) on the improvement of the mandibular movements and painful symptoms in individuals with temporomandibular disorders (TMD). Forty patients were randomly divided into two groups (n=20): Group 1 received the effective dose (GaAlAs laser λ 830 nm, 40 mW, 5J/cm²) and Group 2 received the placebo application (0 J/cm²), in continuous mode on the affected condyle lateral pole: superior, anterior, posterior, and posterior-inferior, twice a week during 4 weeks. Four evaluations were performed: E1 (before laser application), E2 (right after the last application), E3 (one week after the last application) and E4 (30 days after the last application). The Kruskal-Wallis test showed significant more improvements (p<0.01) in painful symptoms in the treated group than in the placebo group. A significant improvement in the range of mandibular movements was observed when the results were compared between the groups at E4. Laser application can be a supportive therapy in the treatment of TMD, since it resulted in the immediate decrease of painful symptoms and increased range of mandibular movements in the treated group. The same results were not observed in the placebo group.

Oral Jaw Behaviors in TMD and Bruxism: A Comparison Study by Severity of Bruxism

ABSTRACT The purpose of this study was to document the prevalence of oral jaw behaviors concomitant to bruxism in TMD+bruxing behavior patients and in nonbruxer controls. Clinical examination, questionnaires, and specific criteria to allocate patients to mild, moderate, and severe groups of TMD and bruxers were used. The sample consisted of 274 TMD + bruxing behavior patients and 52 control non-bruxing behavior groups evaluated at the Center for the Study of TMD. The mean age of the TMD+ bruxing behavior group was about 33.11 years old (range 16.66, SD = 11.52) as compared to 34.90 years old (range 17–67, SD = 14.26) in the control group. Oral jaw behaviors were assessed in the mild, moderate, and severe TMD+bruxing groups, and in the corresponding control group. It was found that the prevalence of oral jaw behaviors was higher in the TMD+bruxing behavior group as compared to the control. Hence, concomitant oral jaw behaviors predominated in bruxers and increased with its severity. The data reinforce the need to assess TMD patients in terms of the presence of bruxism, its severity, and concomitant oral jaw habits. Such approach will enable the clinician to have better understanding about the role of these behaviors in TMD. Epidemiological data was also provided regarding jutting the jaw forward (a rarely-described oral jaw habit) in a relatively large sample of TMD+bruxing patients, suggesting a more clinical intervention in children and adolescents. This study is the first to document the prevalence of specific oral jaw habits in a relatively large sample of TMD+bruxing behavior classified by degree of severity. Results suggest that TMD+bruxing patients may present many other additional oral jaw habits which may concur to increase masticatory muscle activity thus leading to TMD signs and symptoms. Factors responsible for the increased frequency of oral jaw habits with the severity of bruxism behavior remain unknown and therefore further studies are needed.

Evaluation of Low Intensity Laser Therapy In Myofascial Pain Syndrome

Abstract Limited studies have demonstrated that low intensity laser therapy (LILT) may have a therapeutic effect on the treatment of myofascial pain syndrome (MPS). Sixty (60) patients with MPS and having one active trigger point in the anterior masseter and anterior temporal muscles were selected and assigned randomly to six groups (n=10): Groups I to III were treated with GaAlAS (780 nm) laser, applied in continuous mode and in a meticulous way, twice a week, for four weeks. Energy was set to 25 J/cm2, 60 J/cm2 and 105 J/cm2, respectively. Groups IV to VI were treated with placebo applications, simulating the same parameters as the treated groups. Pain scores were assessed just before, then immediately after the fourth application, immediately after the eighth application, at 15 days and one month following treatment. A significant pain reduction was observed over time (p<0.001). The analgesic effect of the LILT was similar to the placebo groups. Using the parameters described in this experiment, LILT was effective in reducing pain experienced by patients with myofascial pain syndrome. Thus, it was not possible to establish a treatment protocol. Analyzing the analgesic effect of LILT suggests it as a possible treatment of MPS and may help to establish a clinical protocol for this therapeutic modality.

A Preliminary Protocol for Multi-Professional Centers for the Determination of Signs and Symptoms of Temporomandibular Disorders

Abstract The objective of the present study was to test a protocol for the quantification of the frequency and severity of signs and symptoms of temporomandibular disorders (TMD) according to patient perception during two phases of investigation. The protocol was developed based on the signs and symptoms most frequently reported in the literature and on the circumstances in which they produce discomfort. Eighty-four patients diagnosed with TMD by functional examination of the masticatory system responded to the protocol questions and indicated the severity of signs and symptoms using an eleven point numerical scale (Phase 1). Forty-two patients were fitted with an occlusal splint (treated group) and the remaining participants did not use a splint (control group). The protocol questions were asked after 50 days of treatment (Phase 2). Based on the results of nonparametric statistical analysis, the incidence of signs and symptoms was high in Phase 1 and significant, with no difference between the groups, whereas the treated and control groups differed in Phase 2. A comparison between Phases 1 and 2 showed that only the treated group presented a reduction in the severity of signs and symptoms. The study showed that using this protocol, it is possible to define the frequency and severity of symptoms as well as the effect of the treatment. The advantage of this protocol is that it would complement the data obtained using clinical examination with information provided by the patient in a measurable manner.

Styloid process elongation and calcification in subjects with tmd: clinical and radiographic aspects

Knowledge of the Eagles syndrome shows that its symptoms can be very easily confused with other types of craniomandibular disorders, especially temporomandibular disorders (TMD). The aim of this study was to find a possible correlation between the presence of TMD and elongation of the styloid process as well relate to presence of calcification of the stilohyoid chain. Fifty patients with TMD, confirmed from the RDC/TMD, were examined clinically and radiographically. Radiographic documentation consisted of digital panoramic radiograph and digital lateral cephalometric radiograph. Radiocef software (Radiomemory) was used for the analysis of radiographs by means of specific cephalometric tracing and linear measurements of the styloid process. Each radiograph was traced and measured three times with intervals of 1 month to spread the error. Statistical analysis was performed by Pearsons test (p=0.001) using Biostat 4.0 statistical software. Result showed an incidence of 76% elongation of the styloid process in the sample. There was a correlation between the bilateral measures taken in panoramic radiographs (?<0.001) and also for measures of styloid process length carried out in different panoramic radiographs and lateral cephalometric radiographs (?<0.001). It was concluded that there is prevalence of elongated styloid process in patients with TMD. However, no relationship was found between measurements on the stylohyoid chain and symptoms of headache, orofacial pain, tinnitus and vertigo.

Severity of TMD Related to Age, Sex and Electromyographic Analysis

Temporomandibular disorders (TMD) are manifested as a group of signs and symptoms that affect a particular population profile. Some variables such as sex and age influence the clinical expression of this condition. This observational descriptive cross-sectional study aimed to correlate the severity of TMD established by the craniomandibular index (CMI) with the variables: age, sex and electromyographic activity of the masseter and anterior temporal muscles. Fifty-four subjects (15 males/39 females) aged between 16 to 65 years (mean age = 41 years) and diagnosed with TMD were evaluated. Severity was determined by the CMI. These subjects also underwent examination by surface electromyography of the masseter and anterior temporal muscles. No correlation was found between age and severity of TMD (p=0.19/r=0.16), however there was a trend of greater severity in young adults (25-50 years). The sex variable in the correlation was positive with the CMI (p=0.03/r=-0.96) and superior to women. A greater EMG activity of the anterior temporal in relation to masseter (p=0.01) was found and the left temporal activity had the highest average (161.5 ± 44.6 Hz). The electromyographic activity of the anterior temporal and right masseter muscles was positively correlated with the Dysfunction Index CMI (p=0.01). The use of CMI to quantify the severity of TMD and of EMG to assess the functionality of the masticatory muscles can be important allies to direct the treatment.

Evaluation of Vickers hardness of different types of acrylic denture base resins with and without glass fibre reinforcement

OBJECTIVE To evaluate the Vickers hardness of different acrylic resins for denture bases with and without the addition of glass fibres. BACKGROUND It has been suggested that different polymerisation methods, as well as the addition of glass fibre (FV) might improve the hardness of acrylic. MATERIALS AND METHODS Five types of acrylic resin were tested: Vipi Wave (VW), microwave polymerisation; Vipi Flash (VF), auto-polymerisation; Lucitone (LT), QC20 (QC) and Vipi Cril (VC), conventional heat-polymerisation, all with or without glass fibre reinforcement (GFR) and distributed into 10 groups (n = 12). Specimens were then submitted to Vickers hardness testing with a 25-g load for 30 s. All data were submitted to anova and Tukeys HSD test. RESULTS A significant statistical difference was observed with regard to the polymerisation method and the GFR (p < 0.05). Without the GFR, the acrylic resin VC presented the highest hardness values, and VF and LT presented the lowest. In the presence of GFR, VC resin still presented the highest Vickers hardness values, and VF and QC presented the lowest. CONCLUSIONS The acrylic resin VC and VW presented higher hardness values than VF and QC resins. Moreover, GFR increased the Vickers hardness of resins VW, VC and LT.