Biomechanical Behavior of Oral Soft Tissues

BACKGROUND: Little attention has been given to understanding the variation in biomechanical behavior of oral soft tissues, and this represents an obstacle for the development of biomaterials that perform with appropriate biomechanical characteristics. With this as our motivation, a uniaxial mechanical analysis was performed on lingual and buccal aspects of the attached gingiva, alveolar mucosa, and buccal mucosa to gain insight into human tissue performance and site-specific mechanical variation. METHODS: A discrete quantitative mechanical evaluation of each soft tissue region using tensile, dynamic compression, and stress relaxation analysis was conducted to correlate tissue structure with function as assessed histologically. RESULTS: Results confirm the keratinized gingiva to have increased tensile strength (3.94 ± 1.19 MPa) and stiffness (Young modulus of 19.75 ± 6.20 MPa) relative to non-keratinized mucosal regions, where densely arranged elastin fibers contribute to a tissue with increased viscoelastic properties. Dynamic compression analysis indicated the instantaneous modulus (E(int)), steady modulus (E(s)), and peak stress increased with loading frequency and strain amplitude, with the highest values found in the buccal attached gingiva. CONCLUSION: These investigations quantify the biomechanical properties of oral soft tissues and show region-to-region variation that details structure-function relationships and provides key parameters to aid development of biomaterials that perform with appropriate biomechanical properties.