Dental occlusal form and gum chewing ability

Dental cusp form has close relationship with the Dental cusp form has close relationship with the chewing pattern and hard food chewing efficiency. However, its effects on soft food chewing, or the mixing ability, had not been closely observed. Objectives: To apply an effective method to evaluate the effects of occlusal form on the ability of homogenizing ingredients in a chewing gum. Methods: A block of sugar-free chewing gum containing 0.02g of hydroxylapatite granules (HA) was chewed by the subject at one session. 6 sessions(5,10,15,20,25 and 30 chews)were performed. 25 young adults who had complete dentition and healthy masticatory system were included in this study. A stone model of the subject's working side upper first molar was obtained and trimmed from posterior to the bucco-palatal cusp line. The image of the trimmed surface was photographed and treated with Photoimpact system. The area included between the two cusps was defined as the functional area (FA) of that tooth. The chewing motion was tracked and analyzed by using BioEGN® jaw tracking system. Homogeneity of HA in the radiographic image of the chewed gum bolus was measured after each chewing session, and was regarded as chewing efficiency (CE) of the subject at that session. Results: It was found that CE increased as chewing stroke number increased. However, the averaged FA (1305±315 pixels) and the CE was not significantly related (R2 = 0.035, p > 0.05). Moreover, the chewing stroke angle near occlusal phase was not related to the FA either (R2 = 0.046, p > 0.05). Conclusions: It seems that for gum chewing, chewing strokes do not often meet the buccal and palatal inclines of the molars and the mixing ability is not strongly affected by the occlusal form of the working side molar.