Mechanical properties of human oral mucosa tissues are site dependent: A combined biomechanical, histological and ultrastructural approach

Abstract

Aim: To investigate load-deformation properties of Thiel-embalmed human oral mucosa tissues and to compare three different anatomical regions in terms of mechanical, histological and ultrastructural characteristic with focus on the extracellular matrix. Materials and Methods: Thirty specimens from three different regions of the oral cavity: attached gingiva, buccal mucosa and the hard palate were harvested from two Thiel-embalmed cadavers. Mechanical properties were obtained, combining strain evaluation and digital image correlation in a standardised approach. Elastic modulus, tensile strength, strain at maximum load and strain to failure were computed and analysed statistically. Subsamples were also analysed using scanning electron microscopy (SEM) and histological analysis. Results: The highest elastic modulus of 37.36 ± 17.4 MPa was found in the attached gingiva group, followed by the hard palate and buccal mucosa. The elastic moduli of attached gingiva differed significantly to the buccal mucosa (p = .01) and hard palate (p = .021). However, there was no difference in the elastic moduli between the buccal mucosa and hard palate (p > .22). The tensile strength of the tissue samples ranged from 1.54 ± 0.5MPa to 3.81 ± 0.9 MPa, with a significant difference between gingiva group and buccal mucosa or hard palate (p = .001). No difference was found in the mean tensile strength between the buccal mucosa and hard palate (p = .92). Ultrastructural imaging yielded a morphological basis for the various mechanical properties found intraorally; the attached gingiva showed unidirectional collagen fibre network whereas the buccal mucosa and hard palate showed multi-directional network, which was more prone to tension failure and less elasticity. Conclusion: This is the first study assessing the various morphological-mechanical relationships of intraoral soft tissues, utilising Thiel-embalmed tissues. The findings of this study suggest that the tissues from different intraoral regions showed various morphological-mechanical behaviour which was also confirmed under the SEM and in the histological analysis.

Comprehensive Evaluation of PAXgene Fixation on Oral Cancer Tissues Using Routine Histology, Immunohistochemistry, and FTIR Microspectroscopy

“…Oral buccal mucosal tissues have low tensile strength when compared to other intraoral sites such as the gingiva and hard palate [10]. Thus, it is not surprising that processing of oral buccal mucosal tissue for histological experiments is a tedious process and suffers from processing errors such as tissue fall-off from slides, wrinkling, and tissue tear.…”

“…In this study, we have characterized the new PAXgene tissue fixation and stabilization reagent on oral buccal mucosal biopsied tissues for routine histological and immunohistochemical applications [8]. Oral buccal mucosal tissue has the lowest tensile strength among other intraoral sites, such as the gingiva and hard palate [10]. Hence, it is not surprising that oral buccal mucosal tissue suffers from histological processing errors, such as tissue fall-off from the slides and wrinkling.…”

Biomechanical Properties of Bone and Mucosa for Design and Application of Dental Implants

“…The experimental testing of viscoelastic properties of dog, porcine and human mucosa and other oral section (palate, gingiva, periodontal ligaments) in vivo and in vitro was carried out or summarized in many studies [ 17 , 19 , 26 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ]. As expected, there is a significant scatter in the data ( Table 2 )—more than for bones—depending on tissue location, conditions, and the deployed testing method.…”

“…It is known that soft tissues including oral ones (mucosa, gingiva, palate, PDL) exhibit complex nonlinear time-dependent behavior [ 17 , 39 , 41 , 42 ]. However, most of the models in literature assume material and geometric linearity with the homogeneity and isotropy of the mucosa.…”

Investigation of dental elastomers as oral mucosa simulant materials

“…The authors' previous study (Choi et al, 2020) had identified the tensile strength and elastic modulus of two Thiel-embalmed cadavers to be location-dependent and ranging from 37.36 MPa ± 17.4 in the attached gingiva group, followed by samples from the hard palate (18.13 MPa ± 4.5) and buccal mucosa (8.33 MPa ± 5.8), which has been identified closest resemblance possible to the human oral mucosa. Defining the mechanical characterization of living human oral tissues has been difficult, due to the ethical issues and difficulties of sourcing tissue samples for testing (Choi et al, 2020;Ottone et al, 2016;Thiel, 1992). Fresh human cadaveric tissues are of extremely limited supply for biomechanical testing and they start to deteriorate rapidly with a potential risk for infection (Choi et al, 2020;Ottone et al, 2016;Thiel, 1992).…”