1 Cheeloo College of Medicine, Department of Orthodontics, Shandong Key Laboratory of Oral Tissue Regeneration, Shandong University, Jinan, China.
2 School and Hospital of Stomatology, Shandong Engineering Laboratory for Oral and Dental Materials, Jinan, China.
3 Azman Hashim International Business School, Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia.
4 Cheeloo College of Medicine, Department of Orthodontics, Shandong Key Laboratory of Oral Tissue Regeneration, Shandong University, Jinan, China - zhangj@sdu.edu.cn.