Why Movement Can Occur
According to the American Association of Orthodontists (AAO), your teeth will naturally move and shift throughout your life, but certain stressors can trigger more prominent movement. The fact is, any tooth can move out of place.
Teeth can also gradually move with age. According to The Dental Daily, a process called mesial drift that occurs as you age causes your teeth to slowly move toward the front of your mouth.
Additionally, a decrease in enamel caused by an injury or acid erosion can have an effect on your overall bite. Enamel loss changes your tooth shape, causing your teeth to move out of alignment. This means that any time your tooth shape is changed, whether from enamel damage, a filling or bruxism, your bite can slowly shift, as well.
Crooked teeth and overcrowding can create hard-to-reach spaces that are prone to bacteria and plaque buildup, even if you're diligent about brushing and flossing daily. These conditions can increase your chances of periodontal (or gum) disease and even result in broken teeth and tooth loss in severe cases.
Unfortunately, if you haven't taken proper care of your teeth or if you have a secondary disease, such as untreated diabetes, tooth loss is a possibility. Missing teeth can cause surrounding teeth to move sideways or downward.