Below are the most common characteristics that can cause adult treatment to differ from treatment for children. However, the same problem for an adult may require jaw surgery. For example, if an adult's lower jaw is too short to match properly with the upper jaw, a severe bite problem may result. The limited amount that the teeth can be moved with braces alone may not correct this bite problem. Bringing the lower teeth forward into a proper bite relationship could require jaw surgery, which would lengthen the lower jaw and bring the lower teeth forward into the proper bite.
Bone loss can also limit the amount and direction of tooth movement that is advisable.
Worn, damaged or missing teeth can make orthodontic treatment more difficult, but more important for the patient to have. Teeth may gradually wear and move into positions where they can be restored only after precise orthodontic movement. Damaged or broken teeth may not look good or function well even after orthodontic treatment unless they are carefully restored by the patient's dentist. Missing teeth that are not replaced often cause progressive tipping and drifting of other teeth, which worsens the bite, increases the potential for periodontal problems and makes any treatment more difficult. Jaw muscle and jaw joint discomfort is commonly associated with bruxing, that is, habitual grinding or clenching of the teeth, particularly at night.