Here are some common conditions best treated by an orthodontist.
Deep bite or Open bite:The patient on the left had a deep bite where their lower front teeth were not visible while their back teeth were biting together. This can lead to premature wear of the front teeth long-term. The patient on the right had an open bite where none of his incisors touched together.
Excessive overjet/Class II or crossbite/Class III: The patient on the left had front teeth protruding several millimeters in front of her lower teeth producing a Class II malocclusion. The patient on the right's upper teeth were behind her lower teeth producing what is commonly referred to as an underbite often seen in Class III occlusions.
Crowding or Spacing: The patient on the left has crowding resulting in some of his teeth being blocked out of his dental arch. The patient on the right had spacing in the upper teeth partly due to the small size of her lateral incisors.
Impacted Teeth: The xray on the left shows impacted (stuck in the bone) upper canine teeth. These teeth often require both a surgical procedure and orthodontics to bring them into the mouth and can often lead to resorption of the roots of adjacent permanent teeth as is seen in this case.