Effect of low-level laser therapy on pain levels in patients with temporomandibular disorders: a systematic review

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Therapeutic response of benzodiazepine, orphenadrine citrate and occlusal splint association in TMD pain

Loss of function, muscle inflammation, and pain are some of the signs and symptoms of temporomandibular dysfunction (TMD). Pharmacological strategies to minimize the clinical manifestation of these disorders often focus on blocking or inhibiting the pain-causing symptom. Resources such as muscle-relaxants, anxiety-relief drugs, and splint therapy are often used to reduce muscular hyperactivity related to TMD muscle pain. This study compares the effect of a randomly ordered association of occlusal splint therapy (S), nonsteroid anti-inflammatory with a muscle-relaxant drug (orphenadrine citrate) (O), and an anxiety-relief drug (benzodiazepine) (B), to ease painful TMD muscle symptoms. Clinical and anamnestic analyses were recorded in accordance with the Helkimo TMD index and applied before and after treatments. Twenty-one group two Helkimo TMD adult female patients were treated, all of whom were subjected to the three random therapeutic associations proposed: SBO, BOS, and OSB. The same operator applied the three specific associations over a period of 21 days in the proposed sequence, seven days for each therapy. The results show that all the groups presented the best results in terms of relief from pain after the therapeutic association (28.5% showed a decrease and 47.6% showed an absence of symptoms). No significant difference was observed among association therapeutic protocols. Copyright © 2003 by CHROMA, Inc.

The effect of adhesive and flowable composite on postoperative sensitivity: 2-Week results

Objective: To measure 2-week postoperative sensitivity in Class II composite restorations placed with a self-etching adhesive (Clearfil SE Bond) or a total-etch adhesive (Prime&Bond NT) with or without a flowable composite as cervical increment. Method and materials: Upon approval by the University of Guarulhos Committee on Human Subjects, 100 restorations were inserted in 46 patients who required Class II restorations in their molars and premolars. Enamel and dentin walls were conditioned with a self-etching primer (for Clearfil SE Bond) or etched with 34% phosphoric acid (for Prime&Bond NT). A 1- to 2-mm-thick increment of a flowable composite (Filtek Flow) was used in the proximal box in 50% of the restorations of each adhesive. Preparations were restored with a packable composite (Surefil). The restorations were evaluated preoperatively and 2 weeks postoperatively for sensitivity to cold, air, and masticatory forces using a visual analog scale. Marginal integrity of the accessible margins was also evaluated. Statistical analysis used a mixed linear model with subject as a random effect. Results: Ninety-eight teeth from 44 subjects were observed at 2 weeks. The type of adhesive and use of flowable composite had no significant effects or interaction for any of the four outcomes of interest, ie, change from baseline to 2 weeks in sensitivity and response time for the cold or air stimulus. For the air stimulus, the overall average change from baseline was not significant for either sensitivity or response time. For the cold stimulus, the overall average change from baseline was significant for both sensitivity and response time. No case of sensitivity to masticatory forces was observed. Conclusion: No differences in postoperative sensitivity were observed between a self-etch adhesive and a total-etch adhesive at 2 weeks. The use of flowable composite did not decrease postoperative sensitivity.

Direct and indirect connections between cochlear root neurons and facial motor neurons: Pathways underlying the acoustic pinna reflex in the albino rat

Cochlear root neurons (CRNs) are involved in the acoustic startle reflex, which is widely used in behavioral models of sensorimotor integration. A short-latency component of this reflex, the auricular reflex, promotes pinna movements in response to unexpected loud sounds. However, the pathway involved in the auricular component of the startle reflex is not well understood. We hypothesized that the auricular reflex is mediated by direct and indirect inputs from CRNs to the motoneurons responsible for pinna movement, which are located in the medial subnucleus of the facial motor nucleus (Mot7). To assess whether there is a direct connection between CRNs and auricular motoneurons in the rat, two neuronal tracers were used in conjunction: biotinylated dextran amine, which was injected into the cochlear nerve root, and Fluoro-Gold, which was injected into the levator auris longus muscle. Under light microscopy, close appositions were observed between axon terminals of CRNs and auricular motoneurons. The presence of direct synaptic contact was confirmed at the ultrastructural level. To confirm the indirect connection, biotinylated dextran amine was injected into the auditory-responsive portion of the caudal pontine reticular nucleus, which receives direct input from CRNs. The results confirm that the caudal pontine reticular nucleus also targets the Mot7 and that its terminals are concentrated in the medial subnucleus. Therefore, it is likely that CRNs innervate auricular motoneurons both directly and indirectly, suggesting that these connections participate in the rapid auricular reflex that accompanies the acoustic startle reflex. © 2008 Wiley-Liss, Inc.

External location of the buccinator muscle to facilitate electromyographic analysis

Electromyography is frequently used to measure the activity of masticatory muscles. It requires the precise setting of the electrodes, which demands the accurate location of the muscle to be evaluated. The purpose of this study was to investigate the accuracy of an external method to locate the buccinator muscle. Fifteen human cadavers were evaluated and planes were etermined on the face using anatomic landmarks. An angle (α) was obtained at the intersection of these planes on the central point of buccinator muscle and measured with a protractor. The value of the angle allows locating the central point of buccinator muscle based on anatomic landmarks on the face. Statistical analysis of the collected data indicated an angle of 90° with 95% reliability, thus proving the efficacy of the proposed method.

The effect of manual therapy on masseter muscle pain and spasm

Introduction: Orofacial pain and pain in the muscles of mastication are frequent symptoms of temporomandibular disorder. The masseter is the closet masticatory muscle to the surface and has the function of raising and retracting the mandible. This muscle has considerable strength and is one of the main muscles involved in the shredding of food It is therefore of utmost importance in the masticatory cycle and generally the most affected by pain and spasms. Objectives: The aim of the present study was to analyze the effect of manual therapy with transversal and circular movements on pain and spasm in the masseter muscle, using electromyography and a visual analogue pain scale (VAPS). Eight women who experienced pain upon palpation of the masseter greater than 6 on the VAPS were selected for participation in the study, which employed electromyography and a VAPS for assessment, followed by manual oral physiotherapy and reevaluation. Results: The statistical analysis revealed a reduction in pain, but there was no significant difference in electromyographic activity (p < 0.05). Conclusion: It was concluded that massage therapy was effective on pain symptoms, but was not capable of altering the electrical activity of the masseter muscle.

Maximal clenching effort influence on the electromyographic activity of the trapezius muscle in healthy subjects

Alteration of the occlusion and the position of the jaw can affect the muscles of the neck, due to a relationship between the masticatory and cervical systems. Thus, the objective of this study was to verify whether the bite in maximal clenching effort, in centric occlusion, in individuals with clinically normal occlusion, and without a history of dysfunction in the masticatory system, influences the electromyographic activity of the upper trapezius muscle. A total of 19 normal individuals participated in the study, 14 of which were women (average age of 25.4 ± 4.14 years), and 5 were men (average age of 24.11 ± 3.28 years). The root mean square (RMS) amplitude and median frequency (MF) of the upper trapezium muscle with 40% and 60% of maximal voluntary contraction were analyzed under pre- and post-maximal clenching effort conditions in centric occlusion. The electromyographic signal was collected with a sampling frequency of 2. kHz and the value in RMS was obtained by a moving window of 200. ms. The paired Student's t-test was used to compare RMS amplitude and MF under pre- and post-maximal clenching effort conditions. The level of significance for each comparison was set to p<0.05. This study concluded that in individuals without a history of dysfunction of the masticatory system, maximum clenching effort in centric occlusion does not alter the electromyographic signal of the upper trapezius. © 2009 Elsevier Ltd.

Eletromiografia dos músculos temporal e masseter em crianças com mordida cruzada posterior direita

This study proposal was to evaluate the changes at a masticatory muscle temporalis and masseter, through a eletromyographic, at ponters of the right unilateral bite posterior, verifying the difference at the eletric activity between right and left sides. Twenty female volunteers, with ages between 7 and 8 (x = 7.4). The eletromyographics signals were collected in both sides in all volunteers in rest situations and in an usual isotonic mastication, right, left and bilateral and the maximun isometric constriction, which sinal was used to the eletric activity amplitude normalization. The results signed that the right masseter muscle presents an expressive statistic difference, if compared with the left masseter muscle during the left and right mastication, suggesting a right unilateral mastication. The muscle haven't gotten any expressive variance in this amplitude which remained to a proximate flat noticed in a right and habitual mastication, suggesting a right and one sided mastication during the left mastication occurs a raise of the eletric signal amplitude of the muscle left masseter. The right masseter muscle haven't gained any expressive variance, which remained in a proximate flat observed in an usual and right mastication, suggesting a muscular pattern hyperfunction next to the dental crossing.

Myositis ossificans traumatica of the medial pterygoid muscle: a case report.

In this report, we present a case of myositis ossificans traumatica (MOT) of the medial pterygoid muscle that had developed after mandibular block anesthesia administered for endodontic treatment of the lower right second molar, demonstrating typical features of this condition. MOT should be considered as a differential diagnosis when there is severe limitation of jaw opening and an associated trauma. Panoramic radiographs and axial and coronal computed tomography (CT) scans can effectively delineate the calcified mass. Other imaging studies that may be helpful include magnetic resonance imaging (MRI), bone scans, and ultrasound. As shown in our case, calcified masses were found in the right mandibular angle, which severely limited jaw opening. Some earlier reported cases of MOT were treated by extraoral surgical approaches with complete removal of the evolving muscle. The aim of this case report is to present only the diagnostic imaging aspects of myositis ossificans traumatica.

Relationship between psychological factors and symptoms of TMD in university undergraduate students.

Temporomandibular disorders is a collective term used to describe a number of related disorders involving the temporomandibular joints, masticatory muscles and occlusion with common symptoms such as pain, restricted movement, muscle tenderness and intermittent joint sounds. The multifactorial TMD etiology is related to emotional tension, occlusal interferences, tooth loss, postural deviation, masticatory muscular dysfunction, internal and external changes in TMJ structure and the various associations of these factors. The aim of this study was to evaluate the prevalence of the relationship between signs of psychological distress and temporomandibular disorder in university students. A total 150 volunteers participated in this study. They attended different courses in the field of human science at one public university and four private universities. TMD was assessed by the Research Diagnostic Criteria (RDC) questionnaire. Anxiety was measured by means of a self-evaluative questionnaire, Spielberger's Trait-State anxiety inventory, to evaluate students'state and trait anxiety. The results of the two questionnaires were compared to determine the relationship between anxiety levels and severity degrees of chronic TMD pain by means of the chi-square test. The significance level was set at 5%. The statistical analysis showed that the TMD degree has a positive association with state-anxiety (p = 0.008; p < 0.05) and negative with trait-anxiety (p = 0.619; p < 0.05). Moreover a high TMD rate was observed among the students (40%). This study concluded that there is a positive association between TMD and anxiety.

Assistência Odontológica em Crianças com Paralisia Cerebral e Perspectivas Tecnológicas de Reabilitação

The improvement of oral health and quality of life is closely related to transdisciplinary dialogue, technological development and social responsibility. In patients with cerebral palsy, the lesion of motor areas of the brain compromises the development and function of the craniofacial complex. Considering all the ethiopathogenic conditions, the treatment of such patients involves great difficulties. The dentist and other professionals related to their rehabilitation need to deal with difficulty in chewing, respiration, phonation, besides the poor oral hygiene resulted from abnormal involuntary movements of facial and masticatory musculature, tongue, and upper limb. It is also relevant the lack of understanding about the importance of oral health care due to mental deficits of these individuals. This study aims to review some aspects of oral health in patients with cerebral palsy proposing rehabilitation associated to technology. Few studies concerned about the effectiveness of therapies for oral rehabilitation in patients with cerebral palsy. Laser therapy, electromyography, electrostimulation and LED therapy should be analyzed as options for treatment of patients with cerebral palsy. Following research projects should focus more attention on the dynamic and oral function of these patients to achieve positive repercussions in their overall health. © ArquiMed, 2010.

In vitro study of shear bond strength in direct bonding of orthodontic molar tubes

Objective: Although direct bonding takes up less clinical time and ensures increased preservation of gingival health, the banding of molar teeth is still widespread nowadays. It would therefore be convenient to devise methods capable of increasing the efficiency of this procedure, notably for teeth subjected to substantial masticatory impact, such as molars. This study was conducted with the purpose of evaluating whether direct bonding would benefit from the application of an additional layer of resin to the occlusal surfaces of the tube/tooth interface. Methods: A sample of 40 mandibular third molars was selected and randomly divided into two groups: Group 1 - Conventional direct bonding, followed by the application of a layer of resin to the occlusal surfaces of the tube/tooth interface, and Group 2 - Conventional direct bonding. Shear bond strength was tested 24 hours after bonding with the aid of a universal testing machine operating at a speed of 0.5mm/min. The results were analyzed using the independent t-test. Results: The shear bond strength tests yielded the following mean values: 17.08 MPa for Group 1 and 12.60 MPa for Group 2. Group 1 showed higher statistically significant shear bond strength than Group 2. Conclusions: The application of an additional layer of resin to the occlusal surfaces of the tube/tooth interface was found to enhance bond strength quality of orthodontic buccal tubes bonded directly to molar teeth.

Electromyographic analysis of masseter and anterior temporalis muscle in sleep bruxers after occlusal splint wearing

Bruxism is widely defined as an anxiety response to environmental stress. Occlusal splints are frequently used in sleep bruxism, to protect teeth from damage resulting from the contraction force of mandibular muscles, or to reduce the orofacial pain by relaxing masticatory muscles. Surface electromyography (EMG) of the right and left masseter and temporalis muscles was performed in 15 women presenting sleep bruxism and temporomandibular disorders related to occupational stress, after nocturnal use of the occlusal splint. The EMG signals were recorded twice per patient: After a work shift (pre-splint) and after a night of sleep with the occlusal splint (post-splint) before a new workday. The parametric t-paired test was used to compare differences of the RMS amplitude between pre and post-splint records, for resting and maximal clenching effort. The level of significance for each comparison was set to p < 0.05. The results of the study supports the premise that the use of occlusal splint reduces EMG activity in the masseter and anterior temporalis muscles, in patients who presented with sleep bruxism related to occupational stress. © 2011 Elsevier Ltd.

Speech therapy intervention before dental management in patients with special needs: A case report

Fragile X syndrome is a cytogenetic abnormality related to chromosomal X. This syndrome is frequently associated to intellectual disability, psychological problems, as well as heart, skeletal and join alterations. Intraoral anomalies include malloclusion, ogival palate, cleft palate, presence of mesiodens, dental hypomineralization and abrasion of the occlusal surfaces and incisai edges. The study of characteristics of this syndrome is important for the dentist in order to guide dental treatment and prevention. The aim of this study is to present a myofunctional therapy protocol, evaluated by surface electromyography. A case of a 21 year-old young man who attended the Training Program in Dentistry for Persons with Disabilities, School of Dentistry of São José dos Campos/UNESP is reported. He underwent myofunctional therapy before dental treatment and the masticatory muscles were evaluated by surface electromyography. The exercises of myofunctional therapy consisted of active and passive simple movements of opening and closing the mouth, tongue protrusion and retrusion, digital manipulation and also by using an electric massager on intraoral and perioral region of the masseter, buccinator and orbicularis oris. Action potentials of the masticatory muscles decreased in almost all the muscles and values for the bite force and mandibular opening capacity increased. This study showed that brief and immediate myofunctional therapy optimized clinical practice with positive repercussion on dental care.

New approaches to dental occlusion: A literature update

Because the study of occlusion is a basic area in dentistry, its components, physiology and integration with the stomatognathic system (SS) have been the subject of interest in the scientific literature. However, the focus given to this issue has changed substantially. Currently, new approaches have been proposed in order to update concepts and to demonstrate the full integration and functionality of this system within the human body. With this approach, the authors proposed the following literature review aimed at gathering recent papers (published from 2000 to 2010) with innovative study design, methodology and/or results. The authors' intention is to show the main trends in the study of occlusion and the SS. The literature review was conducted in the PubMed database, using initially the term dental occlusion as a key-word. As items of interest were found, papers were grouped by categories according to their main subject matter. Forty-seven articles were selected and the main categories obtained were: 1. functional magnetic resonance imaging (fMRI); 2. brain activation; 3. masticatory/occlusal function; 4. body function and physical performance; 5. osseoperception; 6. finite element models; and 7. occlusion and pain. Observing the current literature, the authors found that recent studies present different methodologies for the study of occlusion. These studies have allowed scientists to obtain detailed information about the physiology of occlusion and the SS, as well as about its integration in the body. Research in this area should be continued in order to clarify, in detail, the role of each component of the SS and its interaction with human physiology. © 2012 by CHROMA, Inc.