Final answer:
Patients at risk for periodontal disease are those who have lost 2 mm or more of periodontal attachment, and maintaining oral hygiene is vital for prevention and management.
Step-by-step explanation:
Patients at risk for periodontal disease are those who have lost 2 mm or more of periodontal attachment. The progression of periodontal disease includes the stages of gingivitis, which then may develop into periodontitis when there is a recession of the gum tissue. This can expose parts of the tooth normally covered by gums, leading to unprotected areas where bacteria can spread and potentially cause tooth loss. The periodontal ligaments, made of collagen fibers, are essential for connecting the roots of the teeth to the jaws. Maintaining good oral hygiene is crucial in preventing and managing periodontal diseases.