Thermographic characterization of masticatory muscle regions in volunteers with and without myogenous temporomandibular disorder: preliminary results.

OBJECTIVES: This study aims to conduct a non-invasive measurement of the cutaneous temperature of selected masticatory muscle regions of volunteers with and without myogenous temporomandibular disorder (TMD), using infrared thermography. METHODS: 23 females (10 myogenous TMD volunteers and 13 controls) were recruited and studied. The temperature at the surface of the facial area over the anterior temporalis and masseter muscles was assessed by medical thermography, using regional lateral views and clinical examination. RESULTS: The temperature levels measured at the masseter and anterior temporalis muscle regions in myogenous TMD volunteers (32.85 ± 0.85 and 34.37 ± 0.64 ºC, respectively) were significantly lower (p < 0.05) than those measured in controls (33.49 ± 0.92 and 34.78 ± 0.44 ºC, respectively). Medical infrared imaging indicated a mean difference of 1.4 ºC between the masseter and anterior temporalis regions. Analysis of the comparison between the absolute and normalized mean temperatures was performed using the pairwise comparison of receiver operating characteristic curves, and no statistically significant difference was observed (p > 0.05). The sensitivity and specificity of the thermographic assessment for the masseter region was of 70% and 73%, respectively and for the anterior temporalis region was of 80% and 62%, respectively. CONCLUSIONS: This method of evaluating masticatory muscle regions of this preliminary study seems to indicate that it can be used as an aid in complimentary diagnosing of TMDs.

Thermographic and clinical correlation of myofascial trigger points in the masticatory muscles.

OBJECTIVES: The aim of the study was to identify and correlate myofascial trigger points (MTPs) in the masticatory muscles, using thermography and algometry. METHODS: 26 female volunteers were recruited. The surface facial area over the masseter and anterior temporalis muscles was divided into 15 subareas on each side (n=780). This investigation consisted of three steps. The first step involved thermographic facial examination, using lateral views. The second step involved the pressure pain threshold (PPT), marking the MTP pattern areas for referred pain (n=131) and local pain (n=282) with a coloured pencil, and a photograph of the lateral face with the head in the same position as the infrared imaging. The last step was the fusion of these two images, using dedicated software (Reporter® 8.5-SP3 Professional Edition and QuickReport® 1.2, FLIR Systems, Wilsonville, OR); and the calculation of the temperature of each point. RESULTS: PPT levels measured at the points of referred pain in MTPs (1.28±0.45 kgf) were significantly lower than the points of local pain in MTPs (1.73±0.59 kgf; p<0.05). Infrared imaging indicated differences between referred and local pain in MTPs of 0.5 °C (p<0.05). Analysis of the correlation between the PPT and infrared imaging was done using the Spearman non-parametric method, in which the correlations were positive and moderate (0.4≤r<0.7). The sensitivity and specificity in MTPs were 62.5% and 71.3%, respectively, for referred pain, and 43.6% and 60.6%, respectively, for local pain. CONCLUSION: Infrared imaging measurements can provide a useful, non-invasive and non-ionizing examination for diagnosis of MTPs in masticatory muscles.

The effect of copper loading on pregnant rats and their offspring.

Wistar albino rats were given copper acetate in the drinking water before and during pregnancy. Histological examination and a copper analysis of the liver and kidneys of the pregnant rats, showed copper deposition with a subsequent inflammatory reaction, in these organs. Examination of 11.5 day old embryos showed moderate retardation of growth and differentiation, especially of the neural tube. Examination of the ossification centers of 21.5 day old fetuses and newborn rats showed reduced numbers of ossification centers in the vertebrae, sternum and forelimb and hindlimb phalanges.