Bruxism seems to be related to altered natural head posture and more intense dental wear. Further studies are necessary to explore bruxism mechanisms.

The aim of this study was to evaluate the effectiveness of physiotherapy to improve the head posture and reduce the signs of bruxism in a group of bruxist children. A single-blind randomized clinical trial was performed. All the subjects were 3- to 6-year old, had complete primary dentition, dental and skeletal class I occlusion and were classified as bruxist according to the minimal criteria of the ICSD for bruxism. For each child, a clinical, photographic and radiographic evaluation of the head and cervical posture were realized with standardized techniques. The children were randomized in an experimental (n = 13) and a control (n = 13) group. A physiotherapeutic intervention was applied to the children of the experimental group once a week, until 10 sessions were completed. Afterwards, the cephalogram and the clinical and photographic evaluation of the head posture were measured again. The data were analysed with the t-test and Mann-Whitney test. The subjects of the experimental group showed statistically significant improvement in the natural head posture. The physiotherapeutic intervention showed to be efficient to improve the head posture at the moment of measurement in the studied children. The relationship between bruxism and head posture, if exists, seems to be worthwhile to examine.

Peptides have become attractive potential agents due to their affinity to cancer cells. In this work, the biological activity of the peptide ΔM4 against melanoma cancer cell line A375, epidermoid carcinoma cell line A431, and non-tumoral HaCaT cells was evaluated. The cytotoxic MTT assay demonstrates that ΔM4 show five times more activity against cancer than non-cancer cells. The potential membrane effect of ΔM4 was evaluated through lactate dehydrogenase release and Sytox uptake experiments. The results show a higher membrane activity of ΔM4 against A431 in comparison with the A375 cell line at a level of 12.5 µM. The Sytox experiments show that ΔM4 has a direct effect on the permeability of cancer cells in comparison with control cells. Infrared spectroscopy was used to study the affinity of the peptide to membranes resembling the composition of tumoral and non-tumoral cells. The results show that ΔM4 induces a fluidization effect on the tumoral lipid system over 5% molar concentration. Finally, to determine the appearance of phosphatidylserine on the surface of the cell, flow cytometry analyses were performed employing an annexin V–PE conjugate. The results suggest that 12.5 µM of ΔM4 induces phosphatidylserine translocation in A375 and A431 cancer cells. The findings of this study support the potential of ΔM4 as a selective agent for targeting cancer cells. Its mechanism of action demonstrated selectivity, membrane-disrupting effects, and induction of phosphatidylserine translocation.