Stomatognathic function in Duchenne muscular dystrophy: a case-control study.

AIM: This study aimed to analyse electromyographic activity, masticatory efficiency, muscle thickness, and bite force of individuals with Duchenne muscular dystrophy (DMD). METHOD: Forty males aged 4-15 years, 20 with DMD and 20 healthy age-, height-, and weight-matched controls, underwent electromyography and ultrasonography of temporalis, masseter, and sternocleidomastoid muscles during postural control of the jaw, mastication, and maximal molar bite force. RESULTS: The normalized electromyography signals showed higher activity in masseter and temporal muscles at rest, during protrusion, left and right laterality, and fatigue condition in the group with DMD than in the comparison group (p≤0.05). For masticatory efficiency of cycles, in analysis of non-habitual chewing of flavourless gum, and habitual chewing of peanuts and raisins, the group with DMD presented lower averages (p≤0.05). For the muscle thickness, the results showed that there was a lower muscle thickness in the group with DMD for all muscles during the rest and maximal voluntary contraction, except for masseter and sternocleidomastoid in the maximal voluntary contraction. In the maximal molar bite force, the group with DMD presented higher values for both sides than the comparison group (p≤0.05). INTERPRETATION: Patients with DMD show muscle changes related to the stomatognathic system, in their activity, bite force, and muscle thickness.

Poly(Vinylidene Fluoride-Trifluorethylene)/barium titanate membrane promotes de novo bone formation and may modulate gene expression in osteoporotic rat model.

Osteoporosis is a chronic disease that impairs proper bone remodeling. Guided bone regeneration is a surgical technique that improves bone defect in a particular region through new bone formation, using barrier materials (e.g. membranes) to protect the space adjacent to the bone defect. The polytetrafluorethylene membrane is widely used in guided bone regeneration, however, new membranes are being investigated. The purpose of this study was to evaluate the effect of P(VDFTrFE)/BT [poly(vinylidene fluoride-trifluoroethylene)/barium titanate] membrane on in vivo bone formation. Twenty-three Wistar rats were submitted to bilateral ovariectomy. Five animals were subjected to sham surgery. After 150 days, bone defects were created and filled with P(VDF-TrFE)/BT membrane or PTFE membrane (except for the sham and OVX groups). After 4 weeks, the animals were euthanized and calvaria samples were subjected to histomorphometric and computed microtomography analysis (microCT), besides real time polymerase chain reaction (real time PCR) to evaluate gene expression. The histomorphometric analysis showed that the animals that received the P(VDF-TrFE)/BT membrane presented morphometric parameters similar or even better compared to the animals that received the PTFE membrane. The comparison between groups showed that gene expression of RUNX2, BSP, OPN, OSX and RANKL were lower on P(VDF-TrFE)/BT membrane; the gene expression of ALP, OC, RANK and CTSK were similar and the gene expression of OPG, CALCR and MMP9 were higher when compared to PTFE. The results showed that the P(VDF-TrFE)/BT membrane favors bone formation, and therefore, may be considered a promising biomaterial to support bone repair in a situation of osteoporosis.

Ayahuasca Alters Structural Parameters of the Rat Aorta.

Ayahuasca is a hallucinogenic brew traditionally used by Northwestern Amazonian indigenous groups for therapeutic purposes. It is prepared by the decoction of Banisteriopsis caapi with the leaves of Psychotria viridis. Banisteriopsis caapi contains ß-carbolines that are inhibitors of monoamine oxidase and P. viris is rich in dimethyltryptamine, a 5-HT(1A/2A/2C) agonist. Acute ayahuasca administration produces moderate cardiovascular effects in healthy volunteers, but information regarding long-term use is lacking. This study investigated the effects of ayahuasca (2-4 mL/kg) in the rat aorta after acute and chronic (14 days) administration. Ayahuasca caused flattening and stretching of vascular smooth muscle cells and changes in the arrangement and distribution of collagen and elastic fibers. Chronic treatment with the higher dose significantly increased media thickness and the ratio of media thickness to lumen diameter. More research is needed on the cardiovascular function of long-term ayahuasca consumers.

Low-level laser therapy improves bone formation: stereology findings for osteoporosis in rat model.

Low-level laser therapy (LLLT) benefits bone metabolism, but its use needs to be standardized. We evaluated the effects of LLLT on bone defects in calvaria of ovariectomized rats. Stereology was used to calculate tissue repair volume (V tr ), density of trabecular bone volume (Vv t ), total volume of newly formed trabecular bone (Vtot), and the area occupied by collagen fibers (A C ). Fifty-four Wistar rats were submitted to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups (n = 6), and 24 h after defects, the treatment started with a 780-nm low-intensity GaAlAs laser: G1, G2, and G3 received 3 sessions of 0, 20, and 30 J/cm(2) respectively; G4, G5, and G6 received 6 sessions of 0, 20, and 30 J/cm(2), respectively; and G7, G8, and G9 received 12 sessions of 0, 20, and 30 J/cm(2), respectively. A normal distribution was found for all of the data. The test used to verify the normality was the Kolmogorov-Smirnov (KS, p > 0.05). The one-way ANOVA followed by Tukey's post hoc test was used for data processing. A difference of p < 0.05 was considered statistically significant. Groups G2 and G1 showed significance for V tr , Vv t , Vtot, and (A C ). Results were significant for (Vv t ) and (Vtot) between G3 and G1. There were no significant results between G5 and G4 as well as between G8 and G7. Groups G6 and G4 results showed statistical difference for V tr , Vv t , Vtot, and (A C ). Groups G9 and G7 showed significance for V tr , Vv t , Vtot, and (A C ). In conclusion, there was new bone formation in the groups that received 20 and 30 J/cm(2) when compared to control groups, but over time, the dose of 30 J/cm(2) showed better stereological parameters when compared to 20 J/cm(2).

Aging of masticatory efficiency in healthy subjects: electromyographic analysis--Part 2.

The masticatory process identifies the level of the individual's masticatory ability and provides important information for an adequate diagnosis of the masticatory function. The purpose of this cross-sectional study was to evaluate the influence of age on habitual and non-habitual mastication by means of the values of the ensemble average of masticatory cycles. All volunteers were Brazilian, Caucasian, fully dentate (except for Group I--mixed dentition), aged 7-80 years and divided into five groups: I (7-12 years), II (13-20 years), III (21- 40 years), IV (41-60 years) and V (61-80 years). Except for Group V, which comprised nine women and eight men, all groups were equally divided with respect to gender (20 M/20 F). All subjects were nasal breathers, had normal occlusion and no parafunctional habits or symptoms of temporomandibular dysfunction (RDC/TMD). The masticatory process was analyzed during habitual mastication of peanuts and raisins, and non-habitual mastication of ParafilmM, for 10 seconds each. The resulting electromyographic data were evaluated using SPSS 19.0 software for Windows. ANOVA (analysis of variance) followed by the Duncan test were used to compare the efficiency of the masticatory cycle between age groups. Multivariate analysis (General Linear Models) was used to analyze the effect of age groups and gender on the efficiency of themasticatory cycle, to compare groups (p < 0.05). The results showed that age is directly associated with the changes in masticatory process in healthy subjects.

Resonance frequency analysis of overdenture retainer implants with immediate loading.

OBJECTIVE: To evaluate 16 patients of both sexes with lower overdenture and upper complete dentures, by analysing the resonance frequency of the initial and late stability of implants used to retain the overdenture under immediate loading. BACKGROUND: Oral rehabilitation treatment with complete dentures using implants has been increasingly more common among the specialists in the oral rehabilitation area. This is an alternative for obtaining retention and stability in treatments involving conventional complete dentures, where two implants are enough to retain the overdenture satisfactorily. MATERIALS AND METHODS: The Osstell™ Mentor device was used for the analysis in the initial period (primary stability), 3 and 15 months after the installation of the lower overdenture (secondary stability). The statistical analysis was performed with the repeated measures model (p < 0.01). RESULTS: The implant stability quotients were observed to increase after 15 months of the rehabilitating treatment. CONCLUSION: The use of overdentures over two lower implants should become the treatment of choice for individuals who have a fully edentulous mandible.

Clinical feasibility of mandibular implant overdenture retainers submitted to immediate load.

INTRODUCTION: Millions of people around the world do not have access to the benefits of osseointegration. Treatments involving oral rehabilitation with overdentures have been widely used by specialists in the oral medicine field. This is an alternative therapy for retention and stability achievement in total prosthesis with conventional treatment, and two implants are enough to establish a satisfactory overdenture. OBJECTIVE: The objectives of the study were to evaluate 16 patients of both sexes, with an average age of 47.4±4 years, using electromyographic analysis of masseter and temporal muscles and analyse the increase of incisive and molar maximal bite force with their existing complete dentures and following mandibular implant overdenture therapy to assess the benefits of this treatment. MATERIALS AND METHODS: For these tests, the Myosystem-BR1 electromyograph and the IDDK Kratos dynamometer were used. Statistical analysis was performed using the repeated measures test (SPSS 17.0). RESULTS: A decrease in electromyographic activity during the rest, lateral and protrusion movements and increase of the maximal incisive and molar bite force after 15months with a mandibular implant overdenture was observed. CONCLUSION: All the patients in this study reported a considerable improvement in the masticatory function and prostheses stability following treatment. It is possible to propose that the use of mandibular implants overdenture should become the selected treatment for totally edentulous patients to facilitate oral function and quality of life.

Alterations in masticatory cycle efficiency and bite force in individuals with periodontitis.

OBJECTIVES: The objective of this research was to evaluate the effect of periodontitis on masticatory cycle efficiency and maximum molar bite force. METHODS: Twenty-four individuals were divided into two groups: With periodontitis (Group I; mean age ± standard deviation (SD), 51.3 ± 2.8 years; n = 12) and without periodontitis (Group II; mean age ± SD, 48.9 ± 2.4 years; n = 12). Masticatory cycle efficiency was obtained from the value of the ensemble-averaged integrated linear envelope electromyographic signal of the masseter and temporalis muscles. Maximum bite force was recorded for the right and left molar regions. The data were tabulated and submitted to statistical analysis (P ≤ 0.05). RESULTS: There was a significant difference between the groups for the left masseter muscle when chewing raisins (P = 0.04), peanuts (P = 0.02), and biocapsules (P = 0.01). Multiple regression analysis demonstrated the influence of dental mobility on masticatory cycle efficiency for peanuts (P = 0.03) and biocapsules (P = 0.01). The maximum bite force for the left molar region was significantly different between the groups (P = 0.02). Dental mobility was a variable that had a greater effect on masticatory cycle efficiency. The periodontitis group had a reduced bite force. CONCLUSION: The present study findings indicate that the loss of periodontal supporting structures had a negative impact on masticatory cycle efficiency and molar bite force. This finding suggested that dental mobility should be considered when determining clinical treatments aimed at improving masticatory efficiency and bite force in individuals with the periodontal disease.

Macroscopic and microscopic aspects of the temporomandibular joint related to its clinical implication.

In order to obtain a precise diagnosis and treatment for temporomandibular dysfunctions, it is necessary to have morphological and functional knowledge of the temporomandibular joint. Anatomic components are important to the understanding of the complexity of temporomandibular joint. Nonetheless, just as important are the anatomic relationships that this joint has with the neighboring structures. Thus, the aim of this study was to present the anatomic relationships of the temporomandibular joint in its various surfaces: external or lateral, anterior, posterior, medial, superior, and posterosuperior, considering the morphological and histological aspects. Nine human heads, fixed in formalin (10%) underwent sagittal medial section and were subsequently dissected, evidencing the anatomic components of all surfaces to be analyzed. Components of the external surface were: skin, subcutaneous tissue, lymphatic ganglia, parotid gland, superficial temporal artery, transverse facial artery, zygomatic-orbital artery, superficial temporal vein, facial and auriculotemporal nerves, masseter muscle, and pre-auricular lymphonodus. The anterior surface comprised the masseter and lateral pterygoid muscles (upper and inferior heads), pterygoid venous plexus, mandibular notch, posterior deep temporal artery, masseteric nerve, and deep posterior temporal branches. Medial surface components were: internal maxillary artery, of which middle meningeal artery was one of the closest branches to the TMJ, anterior tympanic artery, inferior alveolar, lingual, auriculotemporal, and chorda tympani nerves, which belonged to the surface posterior to the anterior wall of the auditory duct; auricolotemporal nerve, parotid gland; and petrotympanic fissure. The cerebral fossa (meninges and encephalon) belonged to the superior surface and the ear belonged to the posterosuperior surface. Histologically, the temporomandibular joint is composed by different tissues that compound the mandibular head, mandibular fossa, and articular eminence of the temporomandibular joint. It was concluded that the temporomandibular joint is a complex structure and the clinician must have the ability to formulate the diagnosis based on the understanding of morphological aspects of the structures that compose the stomatognatic system.

Evaluation of molar and incisor bite force in indigenous compared with white population in Brazil.

The purpose of this study was to determine maximum bite force in molar and incisor regions in young Brazilian indigenous individuals, who have had a natural diet since birth, and compare the sample with white Brazilian individuals. To do this, individuals were paired one-to-one (same weight, height, and Class I facial pattern). A secondary purpose was to elucidate the relation between bite force and gender in both populations. Eighty-two Brazilians took part in this study. Participants were aged between 18 and 28 years and were divided into two groups: 41 Xingu indigenous individuals and 41 white Brazilian individuals, with 28 men and 13 women in each group. The inclusion criteria were: having complete dentition; normal occlusion; no neurological, psychiatric or movement disorders; no reports of toothaches; having satisfactory periodontal health; absence of large facial skeletal alterations (typical Class II and Class III individuals); and no previous treatments using occlusal splints. To measure maximum bite force, a digital dynamometer model IDDK (Kratos-Equipamentos Industriais Ltda, Cotia, São Paulo, Brazil) was used, with a capacity of 1000N, adapted for oral conditions. Assessments were made in the first molar (right and left) and central incisive regions. Results reveal that mean maximum bite forces in indigenous individuals of the right molar is 421N, left molar 429N and incisor region is 194N and for white individuals of the right molar is 410N, left molar 422N and incisor region is 117N. Comparing indigenous with white individuals, maximal bite force showed a tendency of being greater in the indigenous group. It was observed that the incisor region showed statistical significance (p<0.0005) but no significance was observed in the molar region. Moreover, indigenous men showed the highest bite force values.

Nocturnal sleep architecture is altered by sleep bruxism.

OBJECTIVE: Sleep is a complex behaviour phenomenon essential for physical and mental health and for the body to restore itself. It can be affected by structural alterations caused by sleep bruxism. The aim of this study was to verify the effects of sleep bruxism on the sleep architecture parameters proposed by the American Academy of Sleep Medicine. DESIGN: The sample comprised 90 individuals, between the ages of 18 and 45 years, divided into two groups: with sleep bruxism (n=45) and without sleep bruxism (n=45). The individuals were paired by age, gender and body mass index: a polysomnography was performed at night. RESULTS: Statistically significant differences were found between (P≤0.05) individuals with sleep bruxism and individuals without sleep bruxism during total sleep time (P=0.00), non-rapid eye movement (NREM) total sleep time (P=0.03), NREM sleep time stage 3 (P=0.03), NREM sleep latency (P=0.05), sleep efficiency (P=0.05), and index of microarousals (P=0.04). CONCLUSIONS: Sleep bruxism impairs the architecture of nocturnal sleep, interfering with total sleep time, NREM sleep latency, and sleep efficiency.

Influence of mandibular tori on stomatognathic system function.

OBJECTIVES: To verify the influence of prominent mandibular tori on the functioning of the stomatognathic system. METHODS: The participants included 40 individuals, divided into two groups: those with mandibular tori (GI group: 20 subjects) and those without mandibular tori (GII group: 20 subjects). The authors used the Myosystem-Br1 electromyography system to analyze electromyographic (EMG) activity. For muscle thickness, images of the masseter and temporalis muscles were captured using the NanoMaxx ultrasound. The maximal molar bite force was obtained by means of the Kratos digital dynamometer. RESULTS: The EMG activity was higher in the masseter muscles in the GI group, compared with the GII group, in all clinical conditions assessed except for the mandibular at rest. In dynamic conditions, this higher EMG activity was also observed in the temporalis muscles. The GI group presented significantly less temporalis muscle thickness than seen in the GII group. The maximal bite force was significantly higher in the GI group. CONCLUSIONS: Mandibular tori promoted morphological and functional changes in the stomatognathic system.

Impact of sleep bruxism on masseter and temporalis muscles and bite force.

OBJECTIVES: This study aimed to analyze the impact of sleep bruxism (SB) on electromyography (EMG) activity and the thickness of the masseter and temporal and maximal molar bite force. METHOD: Ninety individuals, aged between 18 and 45 years, were selected and divided into two groups: Group I (case group, 45 individuals with SB) and Group II (control group, 45 individuals without SB). A diagnosis of SB was made from polysomnography. RESULTS: The data obtained from EMG and the muscle thickness and the maximal molar bite force were tabulated (SPSS 21.0), normalized, and subjected to statistical analysis (p ≤ 0.05). Comparisons between the groups showed significant differences regarding the habitual chewing of hard food for the left temporalis muscle (p = 0.04) and the chewing of soft food for the right masseter muscle (p = 0.04), but no significant differences for the measurements of muscle thickness and maximal molar bite force. DISCUSSION: The present data suggest that SB negatively altered the masticatory muscles' functions. Based on the results of this research, it can be concluded that individuals with SB showed decreased EMG activity in the masticatory muscles.

Effects of cigarette smoke on the Meckel's cartilage of rat fetus: morphologic, morphometric and stereologic study.

The purpose of this study was to investigate the effects of cigarette smoke on the development of the embryo mandible (Meckel's) cartilage in rat fetuses. When inhaled by female Wistar rats between the 9th and the 12th day of pregnancy, cigarette smoke (5 cigarettes a day) caused intrauterine growth retardation, providing smaller fetuses and placentas. In fetuses from the experimental group, the histopathologic examination revealed a poorly developed Meckel's cartilage with smaller chondroblasts showing a scanty cytoplasm with spherical and paler central nuclei, as well as more abundant cartilage matrix. Morphometric analysis revealed that Meckel's cartilage lacunae were smaller in the fetuses from the experimental group, although not showing any remarkable alteration in shape. The results suggested that inhalation of cigarette smoke by pregnant rats during the organogenic period induced growth retardation and delayed cellular differentiation in rat fetal Meckel's cartilage.

Comparative Capabilities of Clinical Assessment, Diagnostic Criteria, and Polysomnography in Detecting Sleep Bruxism.

OBJECTIVE: To evaluate the diagnostic capability of signs and symptoms of sleep bruxism (SB) as per the American Academy of Sleep Medicine (AASM) criteria and a diagnostic grading system proposed by international experts for assessing SB. METHODS: The study was conducted in three phases (interview, physical examination, and sleep studies). Subjects were asked about self-reported tooth grinding sounds occurring during sleep, muscle fatigue, temporal headaches, jaw muscle pain, and jaw locking. A visual examination was conducted to check for presence of abnormal tooth wear. A full-night polysomnography (PSG) was performed. After three phases, the subjects were divided into two groups matched by age and gender: Case Group, 45 SB subjects, and Control Group, 45 non-SB subjects. Diagnostic accuracy measurements were calculated for each sign or symptom individually and for the two diagnostic criteria analyzed. RESULTS: Muscle fatigue, temporal headaches, and AASM criteria were associated with highest sensitivity (78%, 67%, 58%, respectively) and also with highest diagnostic odds ratio (OR = 9.63, 9.25, 6.33, respectively). Jaw locking, muscle pain, and the criterion of "probable SB" were associated with the worst sensitivity (16%, 18%, 22%, respectively). CONCLUSIONS: Presence of muscle fatigue and temporal headaches can be considered good tools to screen SB patients. None of the diagnostic criteria evaluated was able to accurately identify patients with SB. AASM criteria had the strongest diagnostic capabilities and--although they do not attain diagnostic values high enough to replace the current gold standard (PSG)--should be used as a screening tool to identify SB.

The influence of maxillary and mandibular osteoporosis on maximal bite force and thickness of masticatory muscles.

The aim of this study was to examine the bite force and masseter and temporal muscle thickness in individuals with maxillary and mandibular osteoporosis. 72 individuals were distributed into two equal groups: (1) facial osteoporosis and (2) healthy controls. Bite force on the right and left molar regions was recorded with a dynamometer and the highest value out of three measurements was recorded as the maximal bite force. Muscle thickness was measured with a SonoSite Titan ultrasound scanner. Ultrasound images were obtained of the bilateral masseter and temporal muscles at rest and at maximal voluntary contraction. The means of the measurements in each clinical condition were analyzed with multivariate statistical analysis (SPSS 19.0). Student's t test indicated no significant difference for muscle thickness, but indicated significantly lower bite force values in the osteoporosis group (p>0.05). Lower bite force in individuals with facial bone loss demonstrates functional impact of osteoporosis on the complex physiological stomatognathic system.

Comparative effects of retinoic acid or glycolic acid vehiculated in different topical formulations.

Retinoids and hydroxy acids have been widely used due to their effects in the regulation of growth and in the differentiation of epithelial cells. However, besides their similar indication, they have different mechanisms of action and thus they may have different effects on the skin; in addition, since the topical formulation efficiency depends on vehicle characteristics, the ingredients of the formulation could alter their effects. Thus the objective of this study was to compare the effects of retinoic acid (RA) and glycolic acid (GA) treatment on the hairless mouse epidermis thickness and horny layer renewal when added in gel, gel cream, or cream formulations. For this, gel, gel cream, and cream formulations (with or without 6% GA or 0.05% RA) were applied in the dorsum of hairless mice, once a day for seven days. After that, the skin was analyzed by histopathologic, morphometric, and stereologic techniques. It was observed that the effects of RA occurred independently from the vehicle, while GA had better results when added in the gel cream and cream. Retinoic acid was more effective when compared to glycolic acid, mainly in the cell renewal and the exfoliation process because it decreased the horny layer thickness.

Functional analysis of the stomatognathic system in individuals infected with human immunodeficiency virus.

PURPOSE: To understand the effects of HIV type 1 on the function of the masticatory muscles. METHODS: Sixty individuals were selected from both genders, aged between 22 and 57years (mean 36.77±9.33years), and divided into two groups: Group HIVG, 30 individuals with HIV subtype 1, and Group CG, 30 healthy individuals (control group). The individuals were submitted to assessments of their masticatory muscle activity, biting strength and thickness of the masticatory muscles by means of electromyography, maximal molar bite force and ultrasound imaging, respectively. The resultant data were statistically analyzed by t-tests (p<0.05). RESULTS: The HIVG normalized EMG data from a mandibular rest position, protrusion, right and left laterality movement of the jaw showed that HIVG presented a relative increase in EMG activity compared to the CG. The HIVG had a lower masticatory cycle ability while chewing Parafilm M®, Raisins and Peanuts when compared to CG. During rest conditions, the ultrasound images showed a greater average muscular thickness in the right and left temporal region compared to CG. Upon maximal voluntary contraction, an increased average thickness was seen in the temporalis muscles and left sternocleidomastoid muscle when compared to the CG. CONCLUSION: Based on the results of this research, it can be concluded that individuals with acquired immunodeficiency syndrome showed muscular changes related to the stomatognathic system, especially concerning EMG activity and muscle thickness.

Fine structure of the 7 postnatal days Calomys callosus palatine salivary glands.

The aim of this study has been to determine the ultrastructural characteristics of the minor palatine salivary glands on the seventh day of development and to demonstrate wether their secretion is mucous, serous or seromucous by light, transmission and scanning electron microscopy. This study has shown that the palatine gland acinar cells are predominantly mucous with some serous units. These cells contain electron dense (serous) and low electron dense (mucous) granules in the apical portions. The cytoplasmatic organelles like mitochondria, Golgi apparatus and rough endoplasmic reticulum are localized in a supranuclear portion. We could also observe the flattened myoepithelial cells surrounding the basal part of the acini with myofilaments, Golgi apparatus and mitochondria. Desmosomal junctions and membrane interdigitations are present between the acinar and the myoepithelial cells. A basal lamina, divided in two layers, an electron dense and an electron lucent is present between the glandular stroma which is composed of dense connective tissue and the endpieces.

Analysis of endodontist posture utilizing cinemetry, surface electromyography and ergonomic checklists.

The postural risk factors for dentists include the ease of vision in the workplace, cold, vibration and mechanical pressure in tissues, incorrect posture, functional fixity, cognitive requirements and work-related organizational and psychosocial factors. The objective was to analyze the posture of endodontists at the workplace. Eighteen right-handed endodontists aged 25 to 60 years (34±3) participated in the study. Electromyography, kinemetry, ergonomic scales (RULA and Couto's checklist) and biophotogrammetry were used to analyze the posture of endodontists during root canal treatment of the maxillary right first and second molars using rotary and manual instrumentation. The variations observed in the electromyographic activities during the performance of rotary and manual techniques suggest that the fibers of the longissimus region, anterior and medium deltoid, medium trapezium, biceps, triceps brachii, brachioradialis and short thumb abductor muscles underwent adaptations to provide more accurate functional movements. Computerized kinemetry and biophotogrammetry showed that, as far as posture is concerned, rotary technique was more demanding than the manual technique. In conclusion, the group of endodontists evaluated in this study exhibited posture disorders regardless of whether the rotary or manual technique was used.