Effects of heat in the properties of NaOCl alone and mixed with etidronate and alkaline tetrasodium EDTA.

AIM: To assess the free available chlorine concentration (FAC), organic tissue dissolution and smear layer removal capacity of sodium hypochlorite (NaOCl) alone and when mixtured with etidronate (HEDP) and tetrasodium EDTA (Na4 EDTA), and heated to different temperatures. METHODOLOGY: Mixtures at 1 : 1 ratio of 5% NaOCl with distilled water (considered NaOCl alone), 18% HEDP or 10% Na4 EDTA were heated to 25 °C, 37 °C, 48 °C and 60 °C. The FAC in the mixtures was assessed at 5, 10, 20, 30, 60 and 120 min. Samples of bovine muscle tissue (n = 10) were prepared with similar size and weighed before and after 5, 10 and 15 min of immersion in the mixtures heated to the different temperatures to verify organic matter dissolution. The intergroup results were compared statistically using one-way analysis of variance (anova) and intragroup by two-way analysis of variance (anova), both followed by Tukey's multiple-comparison test (α < 0.01). Bovine dentine blocks (n = 10) were analysed by scanning electron microscopy before and after immersion in the mixtures, and the time taken to remove the smear layer from the surfaces of the samples was determined. The Friedman test was used to compare the scores of the same group (α < 0.01), and the Kruskal-Wallis test with Dunn's post hoc was used to compare the different groups (α < 0.01). Saline solution was used as a control in the experiments of tissue dissolution and smear layer removal, RESULTS: Heating NaOCl alone did not affect its FAC. The higher the temperature of the mixtures with the chelators, the lower the FAC. Organic tissue dissolution was improved by increases in temperature of NaOCl alone and its mixture with HEDP (P < 0.01); however, the mixture with Na4 EDTA had no improvement (P > 0.01). Smear layer removal by NaOCl alone was enhanced by heating resulting in lower scores in some samples and became more rapid in the mixtures with the chelators. The saline solution did not promote tissue dissolution nor smear layer removal (P > 0.01). CONCLUSION: In this laboratory study, heating NaOCl alone or when mixed with HEDP improved its capacity to dissolve organic matter and remove the smear layer. However, the mixture with HEDP required frequent refreshment to retain these effects when heated. Due to the acceleration in the reaction between the irrigants, very rapid reductions in the free available chlorine in the mixtures with Na4 EDTA heated to the different temperatures occurred.

Muscle hardness and masticatory myofascial pain: Assessment and clinical relevance.

The impression of increased muscle hardness in painful muscles is commonly reported in the clinical practice but may be difficult to assess. Therefore, the aim of this review was to present and discuss relevant aspects regarding the assessment of muscle hardness and its association with myofascial temporomandibular disorder (TMD) pain. A non-systematic search for studies of muscle hardness assessment in patients with pain-related TMDs was carried out in PubMed, Cochrane Library, Embase and Google Scholar. Mechanical devices and ultrasound imaging (strain and shear wave elastography) have been consistently used to measure masticatory muscle hardness, although an undisputable reference standard is yet to be determined. Strain elastography has identified greater masseter hardness of the symptomatic side in patients with unilateral myofascial TMD pain when compared to the contralateral side and healthy controls (HC). Likewise, shear wave elastography has shown greater masseter elasticity modulus in patients with myofascial TMD pain when compared to HC, which may be an indication of muscle hardness. Although assessment bias could partly explain these preliminary findings, future randomised controlled trials are encouraged to investigate this relationship. This qualitative review indicates that the muscle hardness of masticatory muscles is still a rather unexplored field of investigation with a good potential to improve the assessment and potentially also the management of myofascial TMD pain. Nonetheless, the current evidence in favour of increased hardness in masticatory muscles in patients with myofascial TMD pain is weak, and the pathophysiological importance and clinical usefulness of such information remain unclear.

Test-retest reliability of quantitative sensory testing for mechanical somatosensory and pain modulation assessment of masticatory structures.

Assessing the reliability of medical measurements is a crucial step towards the elaboration of an applicable clinical instrument. There are few studies that evaluate the reliability of somatosensory assessment and pain modulation of masticatory structures. This study estimated the test-retest reliability, that is over time, of the mechanical somatosensory assessment of anterior temporalis, masseter and temporomandibular joint (TMJ) and the conditioned pain modulation (CPM) using the anterior temporalis as the test site. Twenty healthy women were evaluated in two sessions (1 week apart) by the same examiner. Mechanical detection threshold (MDT), mechanical pain threshold (MPT), wind-up ratio (WUR) and pressure pain threshold (PPT) were assessed on the skin overlying the anterior temporalis, masseter and TMJ of the dominant side. CPM was tested by comparing PPT before and during the hand immersion in a hot water bath. anova and intra-class correlation coefficients (ICCs) were applied to the data (α = 5%). The overall ICCs showed acceptable values for the test-retest reliability of mechanical somatosensory assessment of masticatory structures. The ICC values of 75% of all quantitative sensory measurements were considered fair to excellent (fair = 8·4%, good = 33·3% and excellent = 33·3%). However, the CPM paradigm presented poor reliability (ICC = 0·25). The mechanical somatosensory assessment of the masticatory structures, but not the proposed CPM protocol, can be considered sufficiently reliable over time to evaluate the trigeminal sensory function.

Headache attributed to masticatory myofascial pain: impact on facial pain and pressure pain threshold.

There is no clear evidence on how a headache attributed to temporomandibular disorder (TMD) can hinder the improvement of facial pain and masticatory muscle pain. The aim of this study was to measure the impact of a TMD-attributed headache on masticatory myofascial (MMF) pain management. The sample was comprised of adults with MMF pain measured according to the revised research diagnostic criteria for temporomandibular disorders (RDC/TMD) and additionally diagnosed with (Group 1, n = 17) or without (Group 2, n = 20) a TMD-attributed headache. Both groups received instructions on how to implement behavioural changes and use a stabilisation appliance for 5 months. The reported facial pain intensity (visual analogue scale--VAS) and pressure pain threshold (PPT--kgf cm(-2)) of the anterior temporalis, masseter and right forearm were measured at three assessment time points. Two-way anova was applied to the data, considering a 5% significance level. All groups had a reduction in their reported facial pain intensity (P < 0·001). Mean and standard deviation (SD) PPT values, from 1·33 (0·54) to 1·96 (1·06) kgf cm(-2) for the anterior temporalis in Group 1 (P = 0·016), and from 1·27 (0·35) to 1·72 (0·60) kgf cm(-2) for the masseter in Group 2 (P = 0·013), had significant improvement considering baseline versus the 5th-month assessment. However, no differences between the groups were found (P > 0·100). A TMD-attributed headache in patients with MMF pain does not negatively impact pain management, but does change the pattern for muscle pain improvement.

Sida cordifolia leaf extract reduces the orofacial nociceptive response in mice.

In this study, we describe the antinociceptive activity of the ethanol extract (EE), chloroform (CF) and methanol (MF) fractions obtained from Sida cordifolia, popularly known in Brazil as "malva branca" or "malva branca sedosa". Leaves of S. cordifolia were used to produce the crude ethanol extract and after CF and MF. Experiments were conducted on Swiss mice using the glutamate and formalin-induced orofacial nociception. In the formalin test, all doses of EE, CF and MF significantly reduced the orofacial nociception in the first (p < 0.001) and second phase (p < 0.001), which was also naloxone-sensitive. In the glutamate-induced nociception test, only CF and MF significantly reduced the orofacial nociceptive behavior with inhibition percentage values of 48.1% (100 mg/kg, CF), 56.1% (200 mg/kg, CF), 66.4% (400 mg/kg, CF), 48.2 (200 mg/kg, MF) and 60.1 (400 mg/kg, MF). Furthermore, treatment of the animals with EE, CF and MF was not able to promote motor activity changes. These data demonstrate that S. cordifolia has a pronounced antinociceptive activity on orofacial nociception. However, pharmacological and chemical studies are necessary in order to characterize the responsible mechanisms for this antinociceptive action and also to identify other bioactive compounds present in S. cordifolia.

Antinociceptive effect of citronellal in mice.

Citronellal is a monoterpene reported to be a major component of the essential oils in various aromatic species of plants. The present study evaluated the central nervous system depressant and antinociceptive properties of citronellal through behavioral experimental models. Following intraperitoneal injection, citronellal induced the reduction of spontaneous activity, ataxia, analgesia, and sedation. In pentobarbital-induced hypnosis, CTL (citronellal) at 50, 100, and 200 mg/kg (i.p.) significantly increased sleeping time (88.0 +/- 11.4, 100.2 +/- 16.4, and 119.5 +/- 20.9 min) when compared to vehicle solution injections (43.0 +/- 6.1). Citronellal (100 and 200 mg/kg, i.p.) significantly reduced the number of writhes (66.4 and 81.9%) in a writhing test and the number of paw licks during phase 1 (47.0 and 66.8%) and phase 2 (71.1 and 79.2%) of a formalin test when compared to control group animals. In addition, the results of a hot plate test showed central analgesic properties for citronellal (p < 0.05). These results indicate depressant, hypnotic, and antinociceptive properties of this monoterpene.

Trigeminal nociceptive function and oral somatosensory functional and structural assessment in patients with diabetic peripheral neuropathy.

This case-control study primarily compared the trigeminal nociceptive function, the intraoral somatosensory profile and possible structural nerve changes between diabetic peripheral neuropathy (DPN, n = 12) patients and healthy participants (n = 12). The nociceptive blink reflex (nBR) was recorded applying an electrical stimulation over the entry zone of the right supraorbital (V1R), infraorbital (V2R) and mental (V3R) and left infraorbital (V2L) nerves. The outcomes were: individual electrical sensory (I0) and pain thresholds (IP); root mean square (RMS), area-under-the-curve (AUC) and onset latencies of R2 component of the nBR. Furthermore, a standardized full battery of quantitative sensory testing (QST) and intraepidermal nerve fibre density (IENFD) or  nerve fibre length density (NFLD) assessment were performed, respectively, on the distal leg and oral mucosa. As expected, all patients had altered somatosensory sensitivity and lower IENFD in the lower limb. DPN patients presented higher I0, IP, RMS and AUC values (p < 0.050), lower warm detection thresholds (WDT) (p = 0.004), higher occurrence of paradoxical heat sensation (PHS) (p = 0.040), and a lower intraoral NFLD (p = 0.048) than the healthy participants. In addition, the presence of any abnormal intraoral somatosensory finding was more frequent in the DPN patients when compared to the reference group (p = 0.013). Early signs of trigeminal nociceptive facilitation, intraoral somatosensory abnormalities and loss of intraoral neuronal tissue can be detected in DPN patients.

Reproducibility of quantitative sensory testing applied to musculoskeletal orofacial region: Site and sex differences.

BACKGROUND: This study estimated the inter-rater reliability and agreement of the somatosensory assessment performed at masseter and temporomandibular joint (TMJ) region in a group of healthy female and male participants. METHODS: Forty healthy participants (20 men and 20 women) were evaluated in two sessions by two different examiners. Cold detection threshold (CDT), warm detection threshold (WDT), thermal sensory limen (TSL), cold pain threshold (CPT), heat pain threshold (HPT), mechanical detection threshold (MDT), mechanical pain threshold (MPT), wind-up ratio (WUR) and pressure pain threshold (PPT) were assessed on the skin overlying TMJ and masseter body. Mixed ANOVA, intraclass correlation coefficients (ICC) and standard error of measurement (SEM) were applied to the data (α = 5%). Nonoverlapping 95% confidence intervals (95% CI) of ICCs were considered significantly different. RESULTS: The ICCs of 77% of all quantitative sensory testing (QST) measurements were considered fair to excellent (ICCs: 0.47-0.97), and WUR presented the lowest values. The reliability of WDT, TSL and HPT of masseter was significantly higher than TMJ, whereas the MDT reliability of TMJ was higher than masseter. In addition, the following combination of test/sites presented significantly lower ICCs for women: HPT, MDT of TMJ and MPT of both TMJ and masseter. Finally, the highest SEM values were presented for CPT and MPT. CONCLUSION: The overall somatosensory assessment of the masticatory structures performed by two examiners can be considered sufficiently reliable to discriminate participants, except WUR. Possible site and sex influences on the reproducibility parameters should be taken into account for an appropriate interpretation and clinical application of QST. SIGNIFICANCE: The test site and participant's sex can significantly influence the relative reliability and agreement of quantitative sensory testing applied to musculoskeletal orofacial region, which affect the capacity to discriminate participants and to evaluate changes over time.

Evaluation of anti-nociceptive and anti-inflammatory activity of low-level laser therapy on temporomandibular joint inflammation in rodents.

The aim of this study was to investigate the analgesic and anti-inflammatory activity of low-level laser therapy (LLLT) on the nociceptive behavioral as well as histomorphological aspects induced by injection of formalin and carrageenan into the rat temporomandibular joint. The 2.5% formalin injection (FRG group) induced behavioral responses characterized by rubbing the orofacial region and flinching the head quickly, which were quantified for 45 min. The pretreatment with systemic administration of diclofenac sodium-DFN group (10 mg/kg i.p.) as well as the irradiation with LLLT infrared (LST group, 780 nm, 70 mW, 30 s, 2.1 J, 52.5 J/cm(2), GaAlAs) significantly reduced the formalin-induced nociceptive responses. The 1% carrageenan injection (CRG group) induced inflammatory responses over the time-course of the study (24 h, and 3 and 7 days) characterized by the presence of intense inflammatory infiltrate rich in neutrophils, scanty areas of liquefactive necrosis and intense interstitial edema, extensive hemorrhagic areas, and enlargement of the joint space on the region. The DFN and LST groups showed an intensity of inflammatory response that was significantly lower than in CRG group over the time-course of the study, especially in the LST group, which showed exuberant granulation tissue with intense vascularization, and deposition of newly formed collagen fibers (3 and 7 days). It was concluded that the LLLT presented an anti-nociceptive and anti-inflammatory response on the inflammation induced in the temporomandibular joint of rodents.

Antinociceptive, anti-inflammatory and antioxidant activities of aqueous extract from Remirea maritima (Cyperaceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Remirea maritima Aubl., popularly known as "capim-da-praia", is popularly employed in the treatment of diarrhea, kidney disease, fever, and for analgesic and anti-inflammatory purposes through the preparation of teas. Few studies have focused on the chemical composition and its biological properties. AIM OF THE STUDY: This work evaluated the antinocipetive, anti-inflammatory and antioxidant activities of the aqueous extract from Remirea maritima Aubl. as well as the isolation and identification of the chemical compounds. MATERIALS AND METHODS: Compounds were isolated from aqueous extract of Remirea maritima through preparative HPLC and the structures were identified by means of NMR and MS analysis. The tests for antinociceptive, anti-inflammatory, and antioxidant activities, along with motor coordination test (Rota rod), were performed over the aqueous extract. RESULTS: The phytochemical investigation of aqueous extract of Remirea maritima resulted in the isolation of three flavone glycosides. The structures of these compounds were determined by means of MS and 1D and 2D NMR data as vitexin-2″-O-ß-D-glucopyranoside, isovitexin-2″-O-ß-D-glucopyranoside, and luteolin-7-O-glucuronide. Acute pretreatment with aqueous extract (100, 200 or 400mg/kg, i.p.) caused a significant decrease (p<0.001) in the number of abdominal writhes. In the formalin test, higher doses significantly inhibited the late (inflammatory pain) phase of formalin-induced licking (p<0.05 or 0.001). In the hot plate test, there was no significant difference in nociceptive behavior, discarding the possible central effect of the aqueous extract. In the rota rod test, it was verified that the aqueous extract in all concentration evaluated does not alter the motor coordination of mice, such antinociceptive results were unlikely to be caused by motor abnormality. In the peritonitis test, induced by carrageenan, the treatment with aqueous extract produced a significant reduction in leukocyte migration in all concentration evaluated. Additionally, a significant reduction of lipoperoxidation (TBARS test) and in nitric oxide formation (.NO Scavenging assay) was observed in antioxidant activity assay. CONCLUSION: The biological and phytochemical investigations of the aqueous extract of Remirea maritima resulted in the identification of three flavone glycosides that have been described here for the first time in Remirea and effective analgesic activity in various pain models, probably mediated via the inhibition of peripheral mediators which could be related to its strong antioxidant effect observed in vitro.

Phythochemical screening and anticonvulsant activity of Cymbopogon winterianus Jowitt (Poaceae) leaf essential oil in rodents.

Cymbopogon winterianus (Poaceae) is used for its analgesic, anxiolytic and anticonvulsant properties in Brazilian folk medicine. This report aimed to perform phythochemical screening and to investigate the possible anticonvulsant effects of the essential oil (EO) from fresh leaves of C. winterianus in different models of epilepsy. The phytochemical analysis of EO showed presence of geraniol (40.06%), citronellal (27.44%) and citronellol (10.45%) as the main compounds. A behavioral screening demonstrated that EO (100, 200 and 400mg/kg; ip) caused depressant activity on CNS. When administered concurrently, EO (200 and 400mg/kg, ip) significantly reduced the number of animals that exhibited PTZ- and PIC-induced seizures in 50% of the experimental animals (p<0.05). Additionally, EO (100, 200 and 400mg/kg, ip) significantly increased (p<0.05) the latencies of clonic seizures induced by STR. Our results demonstrated a possible activity anticonvulsant of the EO.

Ultrasound and tomographic evaluation of temporomandibular joints in adolescents with and without signs and symptoms of temporomandibular disorders: a pilot study.

OBJECTIVES: Condylar position in the glenoid fossa has been linked to temporomandibular disorders (TMDs); however its importance in TMD aetiology is still unclear. The purpose of this study was to determine joint spaces and condylar position in adolescents with TMDs using ultrasound static images and linear corrected tomograms at the mandibular rest position. METHODS: Craniomandibular index (CMI) and a symptom questionnaire were assessed in 217 subjects aged 12-18 years. Those with the lowest and the highest scores were divided into control (n=20) and SSTMD (presence of signs and symptoms of TMD) groups (n=20). Ultrasound images and tomography were used to measure the distance between the capsule and the lateral surface of the condyle and to determine the condyle location at the mandibular resting position, respectively. RESULTS: The mean distances obtained from ultrasound images did not correlate with CMI scores and they did not differ between the two groups (P>0.05). Posterior positioned condyles were determined on tomograms, and they were more prevalent both in the SSTMD group (P=0.05) and in girls (P<0.05). CONCLUSIONS: Even though there was a significant difference in condyle position between the control and SSTMD groups, determined by axially corrected tomograms, it cannot be inferred that posteriorly positioned condyles can predict TMDs. In addition, there was no association between the articular capsule and the lateral condyle surface distances measured by ultrasound using a 10 MHz linear transducer and the clinical diagnosis of TMD. Further studies in diagnostic imaging of TMJs with ultrasound should be encouraged, since it has some useful diagnostic applications and does not require special facilities.

Molar bite force and its correlation with signs of temporomandibular dysfunction in mixed and permanent dentition.

The aim of the study was to evaluate molar bite force (BF) magnitude and its correlation to the signs of temporomandibular dysfunction (TMD), gender, weight, height and age in 101 students ranging in age from 6 to 18 years (32 boys/21 girls with mixed dentition and 23 boys/25 girls with permanent dentition). TMD clinical signs were evaluated using the Craniomandibular Index (CMI), and two subscales, the Dysfunction Index (DI) and the Palpation Index (PI). BF was determined with a pressurized tube connected to a sensor (MPX5700-Motorola SPS). anova, Tukey's test, and Pearson's and Spearman's coefficients were evaluated. BF was higher in the permanent dentition (P < 0.05). There was no difference in BF between genders within the groups, but boys with permanent dentition had higher values than children with mixed dentition (P < 0.05). The girls with permanent dentition presented negative correlation in BF with PI and CMI (P < 0.05). BF was positively correlated with weight, height and age in the permanent dentition group (P < 0.05). It was concluded that BF increased from mixed to permanent dentition, with an assumed enhancing influence of body variables and ageing. The TMD signs in older girls were correlated to decreasing BF, suggesting an influence of muscle tenderness preventing subjects from exerting maximum BF.

Bite force determination in adolescents with and without temporomandibular dysfunction.

The aims of this study were to compare bite force in adolescents with and without temporomandibular dysfunction (TMD), and to investigate the influence of gender, age, height and weight on bite force magnitude. The TMD was evaluated using a self-report questionnaire and the Craniomandibular Index, which has two subscales, the Dysfunction Index and the Palpation Index. Subjects with lower and upper extremity values were used to integrate the control (Group I -n = 20) and TMD (Group II -n = 20) groups, respectively. In addition, the TMD group should have at least one subjective symptom. Bite force was determined with a transducer, which consisted of a pressurized rubber tube connected to a sensor element (MPX 5700 - Motorola SPS, Austin, TX, USA). Analysis of covariance, Pearson's coefficient, Mann-Whitney and t-tests were applied to analyse the data. The results showed that Group II presented smaller values for bite force than Group I and boys had greater values than girls in Group II (P < 0.05). Bite force values were significantly smaller for girls between groups (P < 0.05), whereas for boys there was no statistical difference. Weak positive correlation between bite force and weight, height and age (P > 0.05) and significant negative correlation between bite force and Palpation and Craniomandibular Indexes (P < 0.05) were found. It was concluded that decreased bite force was correlated with TMD in girls, primarily with muscle tenderness.

Relationship between oral parafunctional/nutritive sucking habits and temporomandibular joint dysfunction in primary dentition.

UNLABELLED: The aim of this study was to evaluate the relationship between nutritive and parafunctional habits and the presence of temporomandibular dysfunction (TMD) in children with primary dentition. METHODS: Ninety nine children, aged 3-5 years, were examined to check for the presence or absence of signs and symptoms of TMD (headache, preauricular pain, earache, masticatory muscle tenderness, deviation on opening, occlusal interference and asymmetric movement of the mandible), oral parafunctions (bruxism, nail biting, finger/thumb sucking, speech alteration, mouth breathing, pacifier and atypical swallowing) and nutritive habits (breast- or bottle-feeding) through interview and clinical examination. The results were submitted to descriptive statistical analysis and Fisher's exact test. RESULTS: The results showed that only atypical swallowing was positively related to TMD (P < 0.0001); other oral parafunctional and nutritive habits were not related to TMD. CONCLUSIONS: It was concluded that parafunctional habits, with the exception of atypical swallowing, and feeding methods were not determinants for the presence of signs and/or symptoms of TMD in the sample of children included in the study.