Final answer:
The purpose of the dentist marking the pockets on the facial and lingual surfaces of the gingival before surgery is to assess the depth of the pockets and track progress over time.
Step-by-step explanation:
The purpose of the dentist marking the pockets on the facial and lingual surfaces of the gingival before beginning surgery is to assess the depth of the pockets. Pockets are spaces that form between the gum line and the teeth due to gum disease. The dentist uses a periodontal probe to measure the depth of the pockets, and marking them allows for accurate measurements and tracking of progress over time.