During orthodontic treatment, poor oral hygiene may result in
1. marginal gingivitis.
2. gingival fibrosis.
3. ulcerative gingivitis.
4. acute periodontitis.
5. juvenile periodontitis.

(1) and (2)

(1) (2) (3)

(1) and (3)

(1) (3) (5)

All of the above.