1. Department of Stomatology, Kunming Medical University Yan’an Hospital, Yan’an Hospital of Kunming, East Ren Min Road 245, Kunming 650051, PR China
2. Department of Infectious Disease, Kunming Third People\'s Hospital, Kunming, PR China.
3. Department of Stomatology, Kunming Medical University Yan’an Hospital, Yan’an Hospital of Kunming, East Ren Min Road 245, Kunming 650051, PR China.
4. Department of Research Management, The Third Affiliated Hospital of Kunming Medical University, Kunming, PR China.