1. Special Treatment, Jinan Stomatological Hospital, Jinan, Shandong, China
2. Department of Prosthodontic, Tianjin Binhai New Area Tanggu Stomatology Hospital, China
3. Department of Oral and Maxillofacial Surgery, Suining Central Hospital, China
4. School of Stomatology, Jining Medical College, Shandong Province, China