1. Department of Periodontics, Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, Texas.
2. Department of Oral Biology, UIC College of Dentistry, Chicago, Illinois.
3. Key Laboratory of Oral Medicine, Guangzhou Institute of Oral Disease, Stomatological Hospital of Guangzhou Medical University, Guangzhou, China.
4. Department of Stomatology, The Fourth Affiliated Hospital, Harbin Medical University, Harbin, China.
5. Department of Periodontics, UIC College of Dentistry, Chicago, Illinois.