Dr.Nakajima graduated from Osaka Dental University in 1990. He was trained at Tsurumi University, Department of Oral and Maxillofacial Surgery as a clinical fellow. In 1992, he attended Harvard School of Dental Medicine, Department of Periodontology as a research fellow. In 1994, he attended the University of Bern, Department of Oral Surgery. He got his PhD degree at Tsurumi University in 2000 and became an ITI fellow in 2004.