On the squamosal suture of KNM-WT 17000.

The extensive overlap of the temporal squama on the parietal in KNM-WT 17000 is restricted to a narrow segment of the arc of the squamosal suture. It appears as a long, narrow, posterosuperior extension onto the calvarial wall. The long axis of this extended strip is aligned with what appears to be the most hypertrophied section of the temporalis muscle fan. The substantial differences between the squamosal suture and associated masticatory elements of KNM-WT 17000 and those of Australopithecus boisei provide an opportunity to evaluate the various forces molding the anatomy of the squamosal suture of A. boisei. It is suggested that the extreme flare of the zygomatic arches in the latter accounts for these differences.     

The development of a simple objective test of mastication suitable for older people,using chewing gums

Aims: To develop and assess a simple test for evaluating the mastication of visco‐elastic foods and prosthodontic success subsequent to treatment of older people. Method: The weight lost from chewing gum during mastication tests and the saliva secreted is weighed. The percentage of the original gum weight that is chewed out in a defined number of strokes is termed the Masticatory Effectiveness (ME) Material: Five edentate and three dentate volunteers were selected to provide a range of dental states and age. Four commercially available chewing gums of different origins and perceived hardness were tested, one without sweetener acted as a control for salivary stimulation. Intervention: Pre‐weighed samples of each gum were chewed, each for defined numbers of strokes. The saliva secreted was collected and weighed. The chewed gum was desiccated and the total weight loss of sweeteners chewed out provided an objective measure of chewing performance. Results: Weight loss showed large differences between gums, between subjects and the number of strokes. ME was significantly correlated with salivary secretion rates for two subjects. The interaction between subject and gum was statistically significant, established by an ANOVA model, the value of which is shown for multivariate studies. Differential success between gums of different thickness may provide evaluation of denture stability. Conclusions: Measuring the weight lost from gums during chewing provides a simple test of masticatory effectiveness of visco‐elastic foods. This has particular value both in functional assessment of older people and in physiological research.