Trigeminal input exerts acute and chronic effects on the brain, modulating cognitive functions. Here, new data from humans and animals suggest that these effects are caused by trigeminal influences on the Locus Coeruleus (LC). In humans subjects clenching with masseter asymmetric activity, occlusal correction improved cognition, alongside with reductions in pupil size and anisocoria, proxies of LC activity and asymmetry, respectively. Notably, reductions in pupil size at rest on the hypertonic side predicted cognitive improvements. In adult rats, a distal unilateral section of the trigeminal mandibular branch reduced, on the contralateral side, the expression of c-Fos (brainstem) and BDNF (brainstem, hippocampus, frontal cortex). This counterintuitive finding can be explained by the following model: teeth contact perception loss on the lesioned side results in an increased occlusal effort, which enhances afferent inputs from muscle spindles and posterior periodontal receptors, spared by the distal lesion. Such effort leads to a reduced engagement of the intact side, with a corresponding reduction in the afferent inputs to the LC and in c-Fos and BDNF gene expression. In conclusion, acute effects of malocclusion on performance seem mediated by the LC, which could also contribute to the chronic trophic dysfunction induced by loss of trigeminal input.

This review paper aims at reporting some of the notable works carried out concerning the use of nanoparticles (NPs) as a means of improving the resistance of fiber-reinforced polymer composite materials (FRPs) and adhesively bonded joints (ABJs) to delamination initiation and propagation. Applications of various nanoparticles, such as carbon-based, ceramic-based and mineral-based are discussed. The main properties that have been considered for improving the delamination and fatigue resistance of FRPs are the interlaminar shear strength, fracture toughness, and fracture energy. On the other hand, cohesive and interfacial strengths have been the focused parameters in the works that considered enhancement of ABJs. The reported results indicate that inclusion of NPs in polymeric matrices leads to improvement of various material properties, even though some discrepancies in the results have been noted. Notwithstanding, additional research is required to address some of the issues that have not yet been tackled, some of which will be identified throughout this review article.

Background: health-related quality of life (HRQOL) represents a secondary endpoint of medical interventions in oncological patients. Our aim was to highlight potential sources of bias that could be encountered when evaluating HRQOL in oral cancer patients. Methods: this review followed PRISMA-ScR recommendations. Participants: patients treated for oral cancer. Concept: HRQOL assessed by EORTC QLQ-C30 and QLQ-H&N35/QLQ-H&N43. A critical appraisal of included studies was performed to evaluate the accuracy of data stratification with respect to HRQOL determinants. Results: overall, 30 studies met the inclusion criteria, totaling 1833 patients. In total, 8 sociodemographic (SDG) and 15 disease/treatment-specific (DT) HRQOL determinants (independent variables) were identified. The mean number of the independent variables was 6.1 (SD, 4.3)—5.0 (SD, 4.0) DT-related and 1.1 (SD, 1.8) SDG-related variables per article. None of the included papers considered all the identified determinants simultaneously. Conclusions: a substantial lack of evidence regarding HRQOL determinants was demonstrated. This strongly weakens the reliability of the reported findings due to the challenging presence of baseline confounding, selection, and omitted variable biases. The proposed approach recommends the use of further evaluation tools that gather more variables in a single score together with a selection of more homogeneous, reproducible, and comparable cohorts based on the identified baseline confounding.

No abstract

The reliability and efficiency of three different numerical modeling approaches for simulating the response of a newly developed 3D fiber-metal laminate (3D-FML), subject to axial impact loading, are considered in this paper. The main objective of the study is to establish the most robust numerical framework for analyzing the performance of such complexly configured hybrid materials subject to axial impact loading in a fairly accurate, yet efficient manner. LS-DYNA finite element software is used for the purpose. The models include: (i) a full 3D solid model, where all 3D-FML constituents are modeled with 3D elements; (ii) a model with intermediate complexity, in which two different element types are used to model the metallic skins and 3D-fiberglass/foam core, respectively; and (iii) a simplified scheme, consisting of a single layer of thin-shell elements, representing all constituents of the FML. An experimental investigation is also conducted in parallel to verify the accuracy of the modeling schemes. Force and axial-shortening histories, energy absorption capacity, and overall qualitative behavior obtained numerically are compared to experimental results. Both accuracy and computation cost are considered as the performance criteria, all with the aim of providing the reader with some perspective for robust modeling of such geometrically sophisticated composites, subject to a complex loading mechanism.

No abstract

Chewing improves cognitive performance, which is impaired in subjects showing an asymmetry in electromyographic (EMG) masseter activity during clenching. In these subjects, the simultaneous presence of an asymmetry in pupil size (anisocoria) at rest indicates an imbalance in Ascending Reticular Activating System (ARAS) influencing arousal and pupil size. The aim of the present study was to verify whether a trigeminal EMG asymmetry may bias the stimulating effect of chewing on cognition. Cognitive performance and pupil size at rest were recorded before and after 1 min of unilateral chewing in 20 subjects with anisocoria, showing an EMG asymmetry during clenching. Unilateral chewing stimulated performance mainly when it occurred on the side of lower EMG activity (and smaller pupil size). Following chewing on the hypotonic side, changes in cognitive performance were negatively and positively correlated with those in anisocoria and pupil size, respectively. We propose that, following chewing on the hypotonic side, the arousing effects of trigeminal stimulation on performance are enhanced by a rebalancing of ARAS structures. At variance, following chewing on the hypertonic side, the arousing effect of trigeminal stimulation could be partially or completely prevented by the simultaneous increase in ARAS imbalance.

One of the most attractive areas of the face are the lips, they are crucial for emotion and communication, both during animation and at rest. Throughout the years, several techniques to obtain permanent lip enhancement have been introduced, such as the use of nonresorbable fillers. The main problem related to permanent fillers is that undesirable results could not always be repaired; although lip sequelae can be addressed surgically, some surgeons will not perform this type of procedure due to its complexity and the lack of guidelines. In this paper, the authors present a case of a labial incompetence developed after lips implant removal performed elsewhere; after clinical examination the patient was planned for surgery, although during preoperative instrumental examination (chest X-ray) a solitary pulmonary nodule was noted; further investigation performed with needle biopsy revealed a lung cancer. For this reason, the surgical procedure planned for lip restoration was not performed; however, the patient asked for a minimally invasive procedure, thus to improve, although temporarily, her lips appearance. For the aforementioned reasons, the patient was treated just with hyaluronic acid injections achieving a pleasant result, solving also the labial incompetence at rest. To the best of the author's knowledge, this paper represents the first one describing the use of hyaluronic acid injections to restore lip competence following surgical removal of permanent implant.