My front tooth use to be straight now it's starting to stick out. what could be causing this?

Tooth Movement: Could be from a crooked lower tooth hitting it too hard and pushing it out of the arch. Also could be from bone loss or infection in the tooth. Please have your dentist evaluate. He will need to take a x-ray and check both the gums and tooth.

A few possibilities: It could be disease (periodontal) weakening the foundation (bone) enabling the tooth to move. It could be changed in the bite putting excess pressure on the tooth causing ti to move. Have it evaluated and treated to prevent further movement.

Teeth move all times: Teeth will move regardless of age. Hence the reason people have retainers after braces. The amount a tooth moves may be dependent on other factors such as gum disease or your bite.

Doctor consult: There may be several things that could be causing the movement of the tooth. I would recommend you consult a local dentist and have an x-ray taken of the area.

Periodontal disease.: This is one of many possibilities: your age, dental health, bite relationship, grinding habits, plus many more possibilities. You need a good dental exam.

Periodontal disease : Periodontal disease weakens tooth attachment and may cause teeth shifting. Please have it checked by your dentist since this is a destructive disease that leads to tooth loss.