This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
Maintenance phase of PDL therapy starts after: 
Select and explain. 
A. Emergency phase, B. Phase I, C. Phase II, D. Phase III
C: Phase II
Answer: C: Phase II 
Explanation: Maintenance (phase IV therapy)—periodontal procedures during the maintenance phase include evaluation of oral hygiene status, presence or absence of local factors, condition of the periodontium (pocket depths, attachment levels, mobility, furcation involvements, mucogingival issues and occlusion) and other pathologic changes. This phase should begin after the completion of phase II therapy. This phase may also be called supportive periodontal therapy.