[Study on measurement of dynamic viscoelasticity of maxillary mucosa]

The purpose of this study is to investigate the viscoelastic properties of the oral mucosa. The handy apparatus which can easily show the rheological properties (i.e., G', G", tan delta) was made for the trial. The principle of this apparatus is to measure the stress and the phase difference produced when the constant sinusoidally oscillating shear deformation is loaded on the viscoelastic materials. This handy trial apparatus was found to be applicable in vivo, as evaluated by the dynamic spectrometers. The viscoelastic properties of the mucosa of the maxilla were investigated with this apparatus. The results were as follows: 1) Viscoelastic values varied in individual cases. 2) In the maxillary ridge area and the median portion, the values of modulus G and tan delta were low. In other words, the stiffness of these areas was low and the recovery from deformation was fast. 3) The values of modulus G and tan delta were high in the side region of the palate. The result showed that in this area there was a high stiffness and the recovery from deformation was slow. 4) In the incisive papilla and the area of flabby gum, the values of modulus G were low and the values of tan delta were high. The low stiffness and the slow recovery from deformation were shown in these areas.