Department of Stomatology China-Japan Union Hospital Jilin University Changchun 130031 Jilin Province China;
Department of Stomatology China-Japan Union Hospital Jilin University Changchun 130031 Jilin Province China;
Department of Stomatology China-Japan Union Hospital Jilin University Changchun 130031 Jilin Province China;
Department of Stomatology China-Japan Union Hospital Jilin University Changchun 130031 Jilin Province China;
Department of Stomatology China-Japan Union Hospital Jilin University Changchun 130031 Jilin Province China;
Keratinized gingiva augmentation; Xenogeneic collagen matrix; Platelet-rich fibrin; Case report;