The effect of food bolus location on jaw movement smoothness and masticatory efficiency

Abstract

Masticatory efficiency in individuals with extensive tooth loss has been widely discussed. However, little is known about jaw movement smoothness during chewing and the effect of differences in food bolus location on movement smoothness and masticatory efficiency. The aim of this study was to determine whether experimental differences in food bolus location (anterior versus posterior) had an effect on masticatory efficiency and jaw movement smoothness. Jaw movement smoothness was evaluated by measuring jerk-cost (calculated from acceleration) with an accelerometer that was attached to the skin of the mentum of 10 asymptomatic subjects, and acceleration was recorded during chewing on two-colour chewing gum, which was used to assessed masticatory efficiency. Chewing was performed under two conditions: posterior chewing (chewing on molars and premolars only) and anterior chewing (chewing on canine and first premolar teeth only). Jerk-cost and masticatory efficiency (calculated as the ratio of unmixed azure colour to the total area of gum, the unmixed fraction) were compared between anterior and posterior chewing with the Wilcoxon signed rank test (two-tailed). Subjects chewed significantly less efficiently during anterior chewing than during posterior chewing (P = 0·0051). There was no significant difference in jerk-cost between anterior and posterior conditions in the opening phase (P = 0·25), or closing phase (P = 0·42). This is the first characterisation of the effect of food bolus location on jaw movement smoothness at the same time as recording masticatory efficiency. The data suggest that anterior chewing decreases masticatory efficiency, but does not influence jerk-cost.

Reliability of a two‐colour chewing gum test to assess masticatory performance in complete denture wearers

“…13 Participants were positioned comfortably in the dental chair and instructed about the test. Five subsequent tests were performed (5,10,20,30 and 50 chewing cycles) in the preferred chewing side. The number of chewing cycles was counted by the operator.…”

“…The assessment of the masticatory performance is helpful for evaluation of the subject's functional ability and to establish treatment strategies for rehabilitation of the impaired oral function . Traditionally, it has been evaluated by comminution tests associated with the sieving method, in which the comminuted median particle size is calculated for a given number of chewing strokes as the objective measurement of masticatory efficiency …”

Effect of complete and partial removable dentures on chewing movements

“…Previous studies have revealed that posterior occlusion plays a key role in coordinating mandibular movement patterns. Partially edentulous patients with missing post‐canine teeth tend to chew the bolus in the anterior region .…”

Short‐term changes in chewing efficiency and subjective evaluation in normal dentate subjects after insertion of oral appliances with an occlusal flat table

“…Colour‐changeable gum is also used to evaluate the chewing efficiency. Commercially available one‐coloured gum is used, and the change in its colour due to chewing is monitored . Chewing efficiency increases significantly over a week of adaptation to new dentures .…”

“…Commercially available onecoloured gum is used, and the change in its colour due to chewing is monitored. [8][9][10][11][12][13] Chewing efficiency increases significantly over a week of adaptation to new dentures. 13 Given that chewing efficiency decreases during the adaptation period, it is supposed that chewing efficiency decreases immediately after insertion of an oral appliance with an occlusal flat table and then recovers to some extent over the subsequent week.…”