Human mandibular shape is associated with masticatory muscle force

Understanding how and to what extent forces applied to the mandible by the masticatory muscles influence its form, is of considerable importance from clinical, anthropological and evolutionary perspectives. This study investigates these questions. Head CT scans of 382 adults were utilized to measure masseter and temporalis muscle cross-sectional areas (CSA) as a surrogate for muscle force, and 17 mandibular anthropometric measurements. Sixty-two mandibles of young individuals (20-40 years) whose scans were without artefacts (e.g., due to tooth filling) were segmented and landmarked for geometric morphometric analysis. The association between shape and muscle CSA (controlled for size) was assessed using two-block partial least squares analysis. Correlations were computed between mandibular variables and muscle CSAs (all controlled for size). A significant association was found between mandibular shape and muscle CSAs, i.e. larger CSAs are associated with a wider more trapezoidal ramus, more massive coronoid, more rectangular body and a more curved basal arch. Linear measurements yielded low correlations with muscle CSAs. In conclusion, this study demonstrates an association between mandibular muscle force and mandibular shape, which is not as readily identified from linear measurements. Retrodiction of masticatory muscle force and so of mandibular loading is therefore best based on overall mandibular shape

Viable Tumor Tissue Adherent to Needle Applicators after Local Ablation: A Risk Factor for Local Tumor Progression

Background. Local tumor progression (LTP) is a serious complication after local ablation of malignant liver tumors, negatively influencing patient survival. LTP may be the result of incomplete ablation of the treated tumor. In this study, we determined whether viable tumor cells attached to the needle applicator after ablation was associated with LTP and disease-free survival. Methods. In this prospective study, tissue was collected of 96 consecutive patients who underwent local liver ablations for 130 liver malignancies. Cells and tissue attached to the needle applicators were analyzed for viability using glucose-6-phosphate-dehydrogenase staining and autofluorescence intensity levels of H&E stained sections. Patients were followed-up until disease progression. Results. Viable tumor cells were found on the needle applicators after local ablation in 26.7% of patients. The type of needle applicator used, an open approach, and the omission of track ablation were significantly correlated with viable tumor tissue adherent to the needle applicator. The presence of viable cells was an independent predictor of LTP. The attachment of viable cells to the needle applicators was associated with a shorter time to LTP. Conclusions. Viable tumor cells adherent to the needle applicators were found after ablation of 26.7% of patients. An independent risk factor for viable cells adherent to the needle applicators is the omission of track ablation. We recommend using only RFA devices that have track ablation functionality. Adherence of viable tumor cells to the needle applicator after local ablation was an independent risk factor for LT

Sex Differences in the Burden and Complications of Diabetes

Purpose of the Review To review the latest evidence on sex differences in the burden and complications of diabetes and discuss the potential explanations for the sex differences described. Recent Findings Diabetes is a strong risk factor for vascular disease, with compelling evidence that the relative risks of vascular diseases conferred by diabetes are considerably greater in women than men. The mechanisms underpinning women’s excess relative risk of vascular disease from diabetes are unknown. Sex differences in the health care provided for the prevention, management, and treatment of diabetes and its complications could contribute to women’s greater excess relative risks of diabetes complications. However, since the excess risk of vascular disease is not seen for other major vascular risk factors, inherent biological factors may be more likely to be involved. In addition to other cardiometabolic pathways, the sex dimorphism in body composition and fat distribution may be particularly important in explaining women’s greater excess risk of the vascular complications of diabetes. Summary There is strong evidence to suggest that diabetes is a stronger risk factor for vascular disease in women than men. Although several mechanisms may be involved, further research is needed to provide new and deeper insights into the mechanisms underpinning sex differences in the association between diabetes and vascular diseases. Such research will inform patients, health care professionals, and policy makers to ensure that women are not disproportionately affected by diabetes, and will help to reduce the burden in both sexes.</p