1. Periodontal diseases in North America;Albandar;Periodontol,2000
2. Periodontal diseases in Asia and Oceania;Corbet;Periodontol,2000
3. Periodontal diseases in Central and South America;Gjermo;Periodontol,2000
4. Periodontal diseases in Europe;Sheiham;Periodontol,2000
5. Clinical relevance of the host responses of periodontitis;Kinane;Periodontol,2000