Carlos dos Reis Pereira de Araújo

Influence of the menstrual cycle on the pressure pain threshold of masticatory muscles in patients with masticatory myofascial pain

OBJECTIVE The aim of this study was to investigate the influence of the menstrual cycle and oral contraceptive (OC) intake on the pressure pain threshold (PPT) of masticatory muscles in patients with masticatory myofascial pain (MFP). STUDY DESIGN The sample was composed of 36 women, divided into 4 groups, according to the presence of MFP and the intake of OC (15 patients had MFP [7 taking OC] and 21 were pain-free controls [8 taking OC]). The algometer-based PPT of masseter and temporalis, and the record of subjective pain by visual analog scale (VAS) were determined during 2 consecutives menstrual cycles at 4 phases (menstrual, follicular, periovulatory, and luteal). A 3-way ANOVA for repeated measurements, Kruskal-Wallis, Friedman, and Dunn tests, with a 5% significant level analyzed the data. RESULTS PPT was significantly lower in MFP patients when compared with controls throughout the experiment (P < .001). The menstrual phases did not influence PPT (P > .05), while the intake of OC seems to raise PPT levels for the left temporalis (P = .01) and right masseter (P = .04). VAS was, in general, higher at the menstrual phase CONCLUSIONS Different phases of the menstrual cycle have no influence on PPT values, regardless of the presence of a previous condition, as masticatory myofascial pain, while the intake of OC is associated with decreased levels of reported pain.

Association Between Sleep Bruxism and Temporomandibular Disorders: A Polysomnographic Pilot Study

Abstract The aim of this study was to verify the association between sleep bruxism (SB) and temporomandibular disorders (TMD) in a sample of 14 TMD patients and 12 healthy control subjects. All participants were evaluated using a clinical questionnaire, visual analog scale (VAS) for TMJ/muscle palpation, and by functional examination. The experimental group was divided into three TMD subgroups: joint sounds and pain, muscular tenderness, and mixed diagnosis. All participants underwent polysomnographic recording (PSG). A second clinical examination was then carried out to verify the relationship between rhythmic masticatory muscle activity and pain/tenderness on the following morning. The experimental and control groups presented VAS mean scores of 36.85±23.73 mm and 0 mm, respectively. The presence of SB was neither associated with TMD (p>0.05) nor with pain on palpation (p>0.05). Further research with a more representative sample of each TMD subgroup is necessary to elucidate its interaction with SB.

Effect of cyclic loading on fracture strength of endodontically treated teeth restored with conventional and esthetic posts

Introduction: Esthetic post and core systems were recently introduced. There are few reports regarding their behavior under cyclic loading. Objectives: This study compared the effect of cyclic loading on survival rate, residual strength and mode of fracture of endodontically treated teeth restored with esthetic and direct metallic post systems subjected to mechanical cyclic loading. Materials and Methods: Thirty canines were endodontically treated, decoronated and prepared for metal free ceramic crowns, leaving 1.5 mm of dentin for ferrule effect. They were distributed in 3 groups and restored as follows: group 1 with zirconia posts (Cosmopost) and glass-ceramic cores (IPS Empress Cosmopost); group 2 with fiber reinforced composite posts (FibreKor) and group 3 with titanium posts (AZthec Anchor). Direct resin composite (Build It FR Resin Composite) was used as core in groups 2 and 3. All specimens were restored with all ceramic crowns (IPS Empress 2). A resin cement/adhesive system (Cement It/Bond It Primer A+B) was used to lute the posts to root canals and metal free porcelain crowns to the teeth preparation. Specimens were subjected to mechanical load of 250 N for 500,000x at a frequency of 1.7 Hz and then to static load until failure in a universal testing machine. Data were analyzed using One-way ANOVA and Fischer Exact tests α=0.05. Results: All groups had 100% survival rate after cyclic loading; fracture strength values (SD) in N were: group 1 = 886.5(170.6), group 2 = 762.2(113.6) and group 3 = 768.9(72.9); there was no difference among groups (p=0.08); the percentage of mode of favorable fracture found was: group 1 = 60%, group 2 = 90% and group 3 = 50%; there was no correlation between the mode of failure and post and core system used (P=0.142). Conclusions: Esthetic post and core systems showed statistically equivalent fracture strength values, mode of failure and survival rate compared to conventional direct metallic post and resin composite core system after cyclic loading.

Partial time use of anterior repositioning splints in the management of TMJ pain and dysfunction: a one-year controlled study

This study aimed at evaluating the effectiveness of partial use of anterior repositioning appliances in the management of TMJ pain and dysfunction when compared to stabilization splints and a control group in a one-year follow-up. Sample was initially constituted by 60 patients, randomly divided into three groups: I- stabilization splints, II- repositioning splints and III- no treatment. The whole sample was evaluated by means of TMJ and muscle palpation, mandibular AROM, analysis of occlusal contacts, joint sounds inspection and Visual Analogue Scale (VAS) for one year; 52 patients composed the final sample. A significant (after 15 days) improvement in pain report (VAS) and palpation index was found for group II (p < or = 0.01). The occurrence of occlusal alterations as posterior open bite or gross interferences after the splint therapy and increased muscle tenderness were not problems in this study. Similar results in joint noises reduction were observed for the entire sample. It was concluded that controlled partial use of repositioning splints is a beneficial tool in the management of intra-articular pain and dysfunction, with no risks of irreversible occlusal changes.O objetivo desse estudo foi avaliar a efetividade das placas oclusais reposicionadoras no controle de patologias intra-articulares da ATM, quando comparadas a um tratamento convencional (placa estabilizadora) e um grupo sem tratamento (controle). A amostra final constou de 52 pacientes portadores de sinais e sintomas de desordens intra-articulares da ATM, divididos, aleatoriamente em tres grupos, de acordo com o procedimento empregado: grupo I (n=20), utilizou placa estabilizadora, grupo II (n=18) utilizou placa reposicionadora e grupo III (n=14), sem nenhum tratamento.Toda a amostra foi acompanhada durante um ano, sendo avaliada atraves de questionarios anamnesicos, palpacao muscular e da ATM, movimentacao mandibular e deteccao de sons articulares.Uma avaliacao da condicao oclusal tambem foi realizada nos diferentes periodos de exame. Os resultados demonstraram uma maior efetividade das placas reposicionadoras na reducao inicial da dor relatada pelo paciente, assim como uma diminuicao na sensibilidade a palpacao na ATM.Todos os grupos mostraram-se semelhantes apos seis meses de controle em relacao aos sintomas, assim como em relacao aos ruidos articulares. Os indices de palpacao muscular mostraram-se melhor para todos os grupos, sendo que a oclusao tambem nao se alterou significantemente. Baseado no acima exposto, conclui-se que a terapia de uso parcial das placas reposicionadoras constitui-se num meio efetivo de controle das patologias intra-articulares da ATM.

Relationship Between Systemic Joint Laxity, TMJ Hypertranslation, and Intra-articular Disorders

ABSTRACT The aim of this study was to evaluate the correlation between general joint hypermobility, temporomandibular joint (TMJ) hypertranslation and signs and symptoms of TMJ intra-articular disorders. One hundred twenty individuals constituted the sample, divided into two groups: Group I (symptomatic) included 60 patients with complaints of joint noises, pain, or jaw locking, and Group II (nonsymptomatic) included 60 people with no TMD complaints. The Beightons hypermobility score addressed the systemic laxity while lateral x-rays taken in both closed and full open mouth positions measured TMJ mobility (condyle hypertranslation). No association was found between intra-articular disorders and systemic hypermobility (p>0.05). A significant negative correlation (p<0.05) was found between age and systemic hypermobility, while no correlation was detected between systemic and TMJ hypermobility (condyle hypertranslation).

Effect of experimental chewing on masticatory muscle pain onset

Objectives To evaluate the effect of a chewing exercise on pain intensity and pressurepain threshold in patients with myofascial pain. Methods Twenty-nine consecutive women diagnosed with myofascial pain (MFP) according to the Research Diagnostic Criteria comprised the experimental group and 15 healthy age-matched female were used as controls. Subjects were asked to chew a gum stick for 9 min and to stay at rest for another 9 min afterwards. Pain intensity was rated on a visual analog scale (VAS) every 3 min. At 0, 9 and 18 min, the pressure-pain threshold (PPT) was measured bilaterally on the masseter and the anterior, medium, and posterior temporalis muscles. Results Patients with myofascial pain reported increase (76%) and no change (24%) on the pain intensity measured with the VAS. A reduction of the PPT at all muscular sites after the exercise and a non-significant recovery after rest were also observed. Conclusion The following conclusions can be drawn: 1. there are at least two subtypes of patients with myofascial pain that respond differently to experimental chewing; 2. the chewing protocol had an adequate discriminative ability in distinguishing patients with myofascial pain from healthy controls.

Ressonância magnética nos desarranjos internos da ATM: sensibilidade e especificidade

OBJECTIVE: the aim of this paper is to review the literature concerning the reliability and applicability of magnetic resonance imaging (MRI) in the diagnosis of temporomandibular joint (TMJ) internal disorders. METHODS: articles that have used TMJ from cadavers to compare MRI findings with anatomic findings, as well as some papers that have compared clinical findings with MRI findings were evaluated. According to the findings identified on these articles, the MRI sensitivity and specificity properties for the TMJ internal disorders diagnosis were calculated. Then, the MRI reliability and applicability for the TMJ internal disorders diagnosis were discussed. RESULTS: 90% of sensitivity and 88% of specificity were found. CONCLUSION: the TMJ MRI presents good sensitivity and specificity for the TMJ internal disorders diagnosis. But dentists should beware and request this exam only in cases where MRI will be essential to the treatment planning.

Evaluation of dry needling and 0.5% lidocaine injection therapies in myofascial pain trigger points in masticatory muscles

OBJECTIVE: The purpose of this study was to compare the effectiveness of trigger points injections using lidocaine 0.5% and dry needling without any kind of home-based rehabilitation program. METHODS: Sixteen patients with myofascial pain and trigger points in masticatory muscles were randomly assigned to two groups and received only one application session. The pressure pain threshold (PPT) was recorded before and after the injection: Ten minutes, 24 hours later, 7, 15, 21 and 30 days after the treatment. Visual analogue scale (VAS) was used to in all evaluation periods. RESULTS: There were no difference between groups for PPT, but for all groups the PPT during the time significantly increased when compared the before treatment. VAS showed differences between groups and during the time. The 0.5% lidocaine had the lowest VAS values when compared to dry needling, but at 30 days there were no differences among them. CONCLUSIONS: Despite the differences in VAS and considering there were no differences in PPT increases, we concluded that, in this study, both groups were able to disrupt the mechanisms of trigger point and relieve the myofascial pain symptoms.