RESUMO
OBJECTIVES: To measure the lengths of the force and resistance arms, in order to calculate the mechanical advantage and muscular work of the human temporalis muscle (TM) in brachyfacial (BR) and dolichofacial (DO) subjects. SETTING AND SAMPLE POPULATION: Mandibles from 49 subjects of both genders (BR n = 9; DO n = 40) from the collection of the Laboratory of Human Anatomy at Universidade de Santa Cruz do Sul, Rio Grande do Sul, Brazil, were analyzed. MATERIAL AND METHODS: The distance between the condylar process and the coronoid process (insertion site of the TM) represented the length of the force arm (LFA ) of the TM. The distance between the condylar process and the mental protuberance represented the length of the resistance arm (LRA ). Thus, the mechanical advantage of the TM was obtained using the following ratio: LFA /LRA , while the muscular work (LRA /LFA ) of the TM was obtained using the inverse of this ratio. RESULTS: When compared with the DO, the parameters of the BR are significantly greater, as shown by the LFA (6.0%) and mechanical advantage (8.2%; p = 0.0078). By contrast, our results show that in the DO, the LRA was 2.4% longer and the muscular work was 10.4% greater (p = 0.0087). CONCLUSION: The mechanical advantage of the TM in BR subjects is significantly greater than in DO subjects. Moreover, this greater mechanical advantage may explain, at least in part, the higher incidence of temporomandibular dysfunctions in BR subjects.
Assuntos
Força de Mordida , Face/anatomia & histologia , Músculo Temporal/anatomia & histologia , Músculo Temporal/fisiologia , Articulação Temporomandibular/anatomia & histologia , Articulação Temporomandibular/fisiologia , Adulto , Fenômenos Biomecânicos , Brasil , Cefalometria , Feminino , Humanos , Masculino , Mandíbula , Côndilo MandibularRESUMO
The electroencephalogram amplitude spectra at 11 fixed frequencies of intermittent photic stimulation of 3 to 24 Hz were combined into driving "profiles" for 14 scalp points in 8 male and 7 female normal subjects aged 9 to 17 years. The driving response varied over frequency and was detected in 70 to 100% of cases in the occipital areas (maximum) and in 27 to 77% of cases in the frontal areas (minimum) using as a criterion peak amplitude 20% higher than those of the neighbors. Each subject responded, on average, to 9.7 +/- 1.15 intermittent photic stimulation frequencies in the right occipital area and to 6.8 +/- 1.97 frequencies in the right frontal area. Most of the driving responses (in relation to the previous background) were significant according to the spectral F-test (alpha = 0.05), which also detected changes in some cases of low amplitude responses not revealed by the peak criterion. The profiles had two maxima in the alpha and theta bands in all leads. The latter was not present in the background spectra in the posterior areas and was less pronounced in the anterior ones. The weight of the profile theta maximum increased towards the frontal areas where the two maxima were similar, while the profile amplitudes decreased. The profiles repeated the shape of the background spectra, except for the theta band. The interhemispheric correlation between profiles was high. The theta driving detected in all areas recorded suggests a generalized influence of the theta generators in prepubertal and pubertal subjects.
Assuntos
Eletroencefalografia , Potenciais Evocados Visuais/fisiologia , Lobo Occipital/fisiologia , Estimulação Luminosa/métodos , Adolescente , Criança , Feminino , Lateralidade Funcional/fisiologia , Humanos , MasculinoRESUMO
The electroencephalogram amplitude spectra at 11 fixed frequencies of intermittent photic stimulation of 3 to 24 Hz were combined into driving "profiles" for 14 scalp points in 8 male and 7 female normal subjects aged 9 to 17 years. The driving response varied over frequency and was detected in 70 to 100 percent of cases in the occipital areas (maximum) and in 27 to 77 percent of cases in the frontal areas (minimum) using as a criterion peak amplitude 20 percent higher than those of the neighbors. Each subject responded, on average, to 9.7 ñ 1.15 intermittent photic stimulation frequencies in the right occipital area and to 6.8 ñ 1.97 frequencies in the right frontal area. Most of the driving responses (in relation to the previous background) were significant according to the spectral F-test (a = 0.05), which also detected changes in some cases of low amplitude responses not revealed by the peak criterion. The profiles had two maxima in the alpha and theta bands in all leads. The latter was not present in the background spectra in the posterior areas and was less pronounced in the anterior ones. The weight of the profile theta maximum increased towards the frontal areas where the two maxima were similar, while the profile amplitudes decreased. The profiles repeated the shape of the background spectra, except for the theta band. The interhemispheric correlation between profiles was high. The theta driving detected in all areas recorded suggests a generalized influence of the theta generators in prepubertal and pubertal subjects.
Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Estimulação Luminosa , Eletroencefalografia , Potenciais Evocados Visuais , Lateralidade Funcional , Lobo OccipitalRESUMO
Rat macrophage monolayers pre-treated with endotoxin release into the incubating fluid a factor (MW greater than 10,000) capable of inducing writhing in mice (MNF). This release was inhibited by dipyrone (3.5-35 micrograms/ml) but not by indomethacin (0.5-2 micrograms/ml). Writhing in mice induced by the factor is blocked by dipyrone (0.5-50 mg/kg) and indomethacin (0.5-2 mg/kg). These results indicate that in addition to the previously described direct blockade of hyperalgesia by dipyrone, this drug may also affect the release of MNF, which induces in vivo nociception through the release of prostaglandin-like substances.