Braces taken off in 1999 and i still wear my retainers. what is causing my lower midline shift?

Midline shift: Have you had regular dental care in the time since you had your braces? What kind of dental treatment have you had? Do you have jaw pain or clicking in your jaw? Do you clench or grind your teeth? Are your teeth loose? There are many reasons that teeth can move. The best way to find out why your teeth have moves is by seeing a dentist for an evaluation.

Good question: Know that teeth shift and change in response to use, wear, muscle balance, etc. all the bones in your body are completely replaced every 7-8 years. Has anyone adjusted your retainers? Do you go for regular dental care? Has your occlusion changed? Have you lost any teeth,mad fillings or crowns done, had any gum/bone loss. Please see an Orthodontic Specialist.