1. Shandong Provincial Key Laboratory of Oral Tissue Regeneration, School of Stomatology, Shandong University, Jinan, Shandong 250012, China
2. Department of Orthodontics, School of Stomatology, Shandong University, Jinan, Shandong 250012, China
3. Department of General Dentistry, School of Stomatology, Shandong University, Jinan, Shandong 250012, China
4. Department of Periodontology, School of Stomatology, Shandong University, Jinan, Shandong 250012, China