Which of the following patients should be referred for orthodontic treatment to close a diastema between maxillary central incisors?
1. An 8-year old with no abnormal oral habits.
2. A 14-year old with no abnormal oral habits.
3. A 3-year old with a 4mm overjet.
4. An 8-year old with a previous thumb habit.

(2) and (4)

(1) (2) (3)

(1) and (3)

(4) only

All of the above.