1. Stomatology Department of Navy General Hospital, Beijing 100048, China
2. State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi’an 710032, China
3. Department of Neurosurgery, PLA Army General Hospital, Beijing 100700, China
4. Department of Stomatology, Lanzhou General Hospital, Lanzhou Military Area Command of Chinese PLA, Lanzhou, Gansu 730050, China
5. Department of Stomatology, PLA Army General Hospital, Beijing 100700, China
6. Department of Endodontics, The Dental College of Georgia, Augusta University, Augusta, GA 30912, USA