Garner J, et al. - Investigators estimated 9 beagle dogs with all premolar teeth extracted and adjacent alveolar bone reduced to explore a novel, shapeable hydrogel tissue expander (HTE) in intraoral sections that had undergone prior expansion and surgery. They noted that blood flow returned to the pre-insertion level within 2 weeks following HTE insertion in both first and second insertions. They found eruption of first and second insertion hydrogels from 4% of the first expansion sites, and 3% of the second expansion sites. No directional migration of the expanding hydrogel was reported at any place. Before bone graft for ridge augmentation, oral mucosa seemed consistently and successfully expanded despite the sites with a history of previous surgeries.