Biomechanical Properties of the Human Soft Palate

Objective: To measure biomechanical properties of the human soft palate and the variation across anatomic regions. Design: Ex vivo analysis of human tissue. Patients/participants: Ten palates harvested from 10 normal adult human cadavers (age range, 37 to 90 years). Interventions: Computer-controlled uniaxial stress-relaxation mechanical properties tested in physiological saline at 37°C. Main Outcome Measures: Measurement of Young modulus, Poisson ratio, and determination of viscoelastic constants c, τ1, and τ2 by curve-fitting of the reduced relaxation function to the data. Results: One hundred sections were tested from the 10 palates, representative of 10 anatomic zones. The mean Young modulus range was 585 Pa at the posterior free edge to 1409 Pa at regions of attachment. The mean Poisson ratio in the inferior-superior direction was 0.45 (SD 0.26) and in the lateral direction, was 0.30 (SD 0.21). The mean viscoelastic constants for 1-mm extensions were C  =  −0.1056 (±0.1303), τ1  =  11.0369 (±9.1865) seconds, and τ2  =  0.2128 (±0.0792) seconds, and for 2-mm extensions were C  =  −0.1111 (±0.1466), τ1  =  14.3725 (±5.2701) seconds, and τ2  =  0.2094 (±0.0544) seconds. Conclusions: The results show agreement with values of the Young modulus estimated by authors (Ettema and Kuehn, 1994; Berry et al., 1999) undertaking finite element modeling of the palate. However, other modulus measurements based on closing pressure are considerably different. The spatial distribution of viscoelastic parameters across the palate shows good consistency.