[Histopathological characteristics of peri-implant soft tissue in reconstructed jaws with vascularized bone flaps].

OBJECTIVE: To analyze the histopathological characteristics of peri-implant soft tissue in reconstructed jaws and the changes after keratinized mucosa augmentation (KMA) with free gingival graft (FGG). METHODS: Twenty patients were enrolled in this study. Five patients of them, who were periodontal and systemic healthy and referred for crown lengthening before restoration with healthy keratinized gingiva collected were enrolled as healthy controls. 15 patients of them were with fibula or iliac bone flaps jaw reconstruction (10 with fibula flap and 5 with iliac flap), who were referred to FGG and implant exposures before restoration. Soft tissue was collected before FGG in reconstructed jaws, and in 5 patients (3 with fibula flap and 2 with iliac flap) 8 weeks after FGG if a second surgery was conducted. Histological analysis with hematoxylin-eosin stain and immunological analysis to interlukin-1 (IL-1), interlukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were performed. RESULTS: Thickness from the bottom of stratum basale to the top of stratum granulosum and thickness of keratinized layer in reconstructed jaws were significantly lower compared with that of natural healthy keratinized gingiva [0.27 (0.20, 0.30) mm vs. 0.36 (0.35, 0.47) mm, P<0.05; 16.49 (14.90, 23.37) µm vs. 26.37 (24.12, 31.53) µm, P<0.05]. In the reconstructed area, thickness from the bottom of stratum basale to the top of stratum granulosum increased after KMA with FGG [0.19 (0.16, 0.25) mm vs. 0.38 (0.25, 0.39) mm, P=0.059] and the thickness of keratinized layer significantly increased after KMA with FGG [16.42 (14.16, 22.35) µm vs. 28.57 (27.16, 29.14) µm, P<0.05], which was similar to that in the control group. Furthermore, the number of positive cells of IL-1, IL-6 and TNF-α significantly increased after KMA [0.67 (0.17, 8.93) vs. 11.00 (9.16, 18.00); 13.00 (8.50, 14.14) vs. 21.89 (15.00, 28.12); 0.22 (0.04, 0.63) vs. 2.83 (1.68, 5.00), respectively, P<0.05] as well as the average optical density value [0.15 (0.14, 0.17) vs. 0.18 (0.17, 0.21); 0.28 (0.26, 0.33) vs. 0.36 (0.33, 0.37); 0.23 (0.22, 0.29) vs. 0.30 (0.28, 0.42), respectively, P<0.05], which was similar to that in the healthy keratinized gingiva. CONCLUSION: The lack of rete pegs and inflammatory factors were common in soft tissue with jaw reconstruction. FGG can improve the quality of the epithelium and may improve the stability of the mucosa around implants.

Detecting formal and informal interests in forest governance.

To reveal the interests of actors in forest governance, this paper proposes a power-based interest identification (PII) approach. Based on the assumption of intentional action, the benefits that actors derive from policy impacts are the result of interest-driven actions. This paper further proposes a theoretical definition of interests that includes formal goals at the social and ecological levels, as well as informal political, economic, and strategic interests. Researchers need to identify powerful actors by identifying power mechanisms and resources, and can then observe actors' formal goals through interviews and documents. For informal interests, the actor observes the informal gains of powerful actors in policy impacts, which are then coded according to political, economic, and strategic interests. Combining these steps, actors can infer the formal and informal interests of powerful actors.•Researchers can verify actors' formal objectives by interview and documents.•Among policy impacts, researchers can observe influences at the social and ecological levels, as well as changes in actors' control, economic gains, and dissemination of ideas.•Researchers can infer informal interests of powerful actors from observation of policy impacts.