Question

1. dead skin that flakes off the scalp due to dryness, infrequent shampooing, or irritation:
2. infection caused by bacteria getting under the gum tissue and destroying the gums and bone:

Explanation:

1. For the scalp flaking condition described, this is a common dry scalp issue known as dandruff (when dryness/irritation is the cause, distinct from fungal seborrheic dermatitis).
2. The bacterial infection affecting gum tissue and underlying bone is a progressive gum disease that destroys supporting structures of teeth.

Answer:

1. Dandruff (dry scalp flakes)
2. Periodontitis (or periodontal disease)