Sabine Otto, Carolina Radetzky, Daniel Christopher Haspinger, Norbert Jakse, Justyna Anna Niestrawska, Teresa Marie Pirker, Martin Siwetz, Niels Hammer, Veronica Antipova
This study investigated the regional and direction-specific tensile properties of native human oral mucosal tissues. Tissue specimens were harvested from three distinct maxillary regions, namely the hard palate, attached gingiva, and alveolar mucosa from 11 partially dentate donors, totaling 34 specimens. Using the osmotic stress protocol to standardize water content, specimens underwent uniaxial tensile testing. Mechanical parameters, including elastic modulus, Cauchy stress and stretch at failure, were calculated and statistically analyzed. The attached gingiva yielded a higher elastic modulus than the alveolar mucosa and a greater Cauchy stress at failure than both the alveolar mucosa and the hard palate, while stretch at failure was similar across all regions examined. No statistically significant direction-dependent differences were detected within the investigated regions. The attached gingiva demonstrated greater variability in elastic modulus and stress values. Collagen fiber coherency and rupture patterns differed between anatomical regions; however, collagen coherency showed no significant overall correlation with elastic modulus or Cauchy stress at failure. Furthermore, failure patterns appear to be site-specific. The present study constitutes the first comprehensive morpho-mechanical characterization of human maxillary mucosa, thereby providing novel insight into region-specific mechanical resilience. These findings hold significant relevance for the optimization of prosthetic design, the advancement of oral biomechanical understanding, and the refinement of computational models in both clinical and bioengineering contexts.