Architecture of Expanded Palatal Tissues Using Self-Inflating Tissue Expanders

Objective: Surgical reconstruction of the palatal tissues is considered challenging owing to the nature of its elastic properties. Recent development of self-inflating tissue expanders has led to an increase in the surface area of palatal tissues for the utilization of surgical flaps. However, few studies on the palatal tissue architecture at the ultrastructural level were found. Therefore, the objectives of this study are to examine the expanded palatal tissues for (i) the surface topography (ii) surface roughness at the macroscopic level and (iii) architecture of the palatal tissue at the ultrastructure level. Method: Two groups of adult male Dorper sheeps (n=5) were used in this study. One group serves as control and the other group was implanted with 3 x 5 mm self-inflating tissue expander discs subperiosteally at the midpalatal suture region under general anesthesia. The expansion rates were monitored for a period over 4 weeks after which the palatal tissues were harvested following euthanasia. The surface roughness and surface topography of the palatal tissue were evaluated using the 3D Alicona System and Biological Atomic Force Microscope (Nanowizard 3, JPK, Germany). Data was analysed using t-test where significance level was set at p<0.05. Result: The surface roughness of the control group (1.29±0.68 µm) was significantly higher than expanded group (0.37±0.08 µm) (p = 0.0182). AFM micrographs showed the collagen fibrils in the control group were randomly distributed. On contrary, in the expanded group the collagen fibrils were found to be parallel with the direction of tissue extension. Conclusion: At the ultrstructural level, it was found that there was an effect of expansion on the architecture of the collagen fibrils. At the macroscopic level, the surface roughness was found to be smoother in expanded group than control group. Further work is required to fully investigate this relationship.