Effect of Hyposalivation on Masticatory Movements While Eating Several Crackers in Healthy Individuals.

Background: Salivation is important during mastication for bolus formation.

Objectives: This study aimed to examine the effect of reduced salivary flow on the mastication of crackers.

Methods: Twenty-one healthy adults were instructed to masticate three foods: rice crackers with (rice cracker 1) and without (rice cracker 2) fat and seasoning and wheat cracker with fat. Atropine sulphate (1 mg) was used to reduce salivary flow.

Results: Hyposalivation significantly extended the masticatory duration (p = 0.020) and masticatory cycle time (p = 0.002) for all test foods. The masticatory cycle time in the late stage significantly increased with hyposalivation of rice cracker 2 (p = 0.002) and wheat cracker (p < 0.001). Suprahyoid muscle activity per masticatory cycle significantly increased with hyposalivation for rice cracker 2 on both the masticatory (p = 0.017) and non-masticatory sides (p = 0.026). There were no differences in these values between the rice cracker 1 conditions. Stimulated salivary flow was the highest in rice cracker 1 (p = 0.002) among the foods.

Conclusion: Taste stimulation can compensate for impaired mastication through the inhibition of salivary flow. Although the fat content can assist in the manipulation of the bolus, the manufacturing process or location of the fat content in the cracker should be considered.