There are a number of problems that can be caused by crooked teeth. These include: Tooth decay – When teeth are crowded together, it can be harder to keep them clean, which can lead to decay. Gum disease – Crooked teeth can make it easier for bacteria to build up around the gum line, causing gum disease. Tooth erosion – If the teeth are not properly aligned, it can put extra stress on them when chewing, which can lead to wear and tear over time. Additionally, acidic foods and drinks can cause more damage to crooked teeth than they would straight teeth.