目的: 分析血管化骨瓣重建颌骨区域种植体周软组织结构特点，以及游离龈移植术后种植体周软组织结构改变，为临床治疗提供指导。方法: 共纳入2020年10月至2022年12月就诊于北京大学口腔医院牙周科的患者20例，其中5例作为健康对照，全身及牙周健康，行牙冠延长术，收集牙冠延长术中切除的部分健康天然角化龈；15例在颌骨重建区域行游离龈移植术，有10例为腓骨瓣重建，5例为髂骨瓣重建，均在术前采集嵴顶软组织，其中5例患者(3例为腓骨瓣重建，2例为髂骨瓣重建)在术后8周时再次采集种植体周软组织。所有软组织采用苏木精-伊红染色观察组织结构特点，测量上皮钉突处基底层底端至颗粒层顶端的厚度及角化层厚度，采用免疫组织化学染色方法检测白细胞介素-1(interlukin-1, IL-1)、白细胞介素-6(interlukin-6, IL-6)、肿瘤坏死因子-α(tumor necrosis factor-α, TNF-α)的分布和表达水平。结果: 与健康天然角化龈相比，颌骨重建患者种植体周黏膜缺乏正常复层鳞状上皮的组织结构，上皮钉突处基底层底端至颗粒层顶端的厚度及角化层厚度更小[0.36 (0.35, 0.47) mm vs. 0.27 (0.20, 0.30) mm, P＜0.05; 26.37 (24.12, 31.53) μm vs. 16.49 (14.90, 23.37) μm, P＜0.05]。游离龈移植术后，上皮钉突处基底层底端至颗粒层顶端的厚度较治疗前呈现增加的趋势[0.38 (0.25, 0.39) mm vs. 0.19 (0.16, 0.25) mm, P=0.059]，角化层厚度较治疗前增加，差异有统计学意义[28.57 (27.16, 29.14) μm vs. 16.42 (14.16, 22.35) μm, P＜0.05]，形成了与健康天然角化龈类似的上皮结构；IL-1、IL-6、TNF-α的阳性细胞个数较术前更多，差异有统计学意义[11.00 (9.16, 18.00) vs. 0.67 (0.17, 8.93), P＜0.05; 21.89 (15.00, 28.12) vs. 13.00 (8.50, 14.14), P＜0.05; 2.83 (1.68, 5.00) vs. 0.22 (0.04, 0.63), P＜0.05]；术后平均光密度值升高，差异有统计学意义[0.18 (0.17, 0.21) vs. 0.15 (0.14, 0.17), P＜0.05; 0.36 (0.33, 0.37) vs. 0.28 (0.26, 0.33), P＜0.05; 0.30 (0.28, 0.42) vs. 0.23 (0.22, 0.29), P＜0.05]，且与健康天然角化龈之间的差异无统计学意义。结论: 颌骨重建区域种植体周角化黏膜缺失或不足的患者，通过游离龈移植行角化黏膜增量有利于改善种植体周黏膜的组织结构，维护种植体周黏膜的稳定性。

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.