Crowding of teeth refers to insufficient space for all teeth to be properly aligned in the arch. Usually we will see teeth that are rotated or teeth that erupt in unwanted locations. Crowding of teeth in the jaw can occur for various reasons. Because of the fundamental principles of genetics we will inhered our parent’s features. Features that can cause crowding of teeth include having large teeth and a small jaw, normal size teeth and a small jaw. Crowding of teeth can also occur due to delayed growth pattern of the jaws. If the teeth are ready to erupt but the jaws have not grown appropriately to provide enough room for the erupting teeth the teeth will come in crooked. Crowding of teeth can also occur in individuals with atypical eruption patterns. Teeth that are retained for too long can cause adjacent teeth to erupt in the space that is available. This will usually lead to the teeth coming in rotated instead of straight and aligned. Premature loss of a tooth can also cause adjacent teeth to drift in the space of the missing tooth and limit the room needed for an eruption in an ideal position.
Whatever the condition, comprehensive orthodontic treatment can correct the problem. The approach taken during treatment of crowding can vary depending upon the age of the individual. If there is crowding of teeth the main objective of treatment is to create enough space and bring the teeth into proper alignment. The space that is needed to bring the teeth into proper alignment can be obtained by one of two ways. If it is determined that the mid-palatal suture has not fused in the orthodontic patient, a palatal expander could be included in phase 1 of orthodontic treatment. Since the mid-palatal suture fuses approximately at the age of twelve, theoretically if the patient is twelve years old and under, the palatal expander can force the upper jaw to grow and provide enough room for all the teeth. Usually when the upper jaw is enlarged, the lower jaw will follow with proportional growth and the lower jaw doesn’t require any expansion. The palatal expander is a fixed appliance that rests on the palate and is attached to the upper teeth. In the middle of the appliance is a small spring that will place lateral pressure on the teeth and jaws and allow them to expand. The treatment time for expansion of the palate can vary, depending on how much room is needed, but usually lasts from 6 months to 1 year. The appliance can be left in after the treatment is completed to allow the jaws to stabilize.
If the patient’s mid-palatal suture has fused, which usually occurs at the age of twelve, crowding of teeth is usually resolved by extraction of first premolars in an effort to provide needed room. First premolars are usually chosen because they usually have short roots and are not beneficial in chewing. However, other teeth can be extracted if there are some potential issues with them, for example large filling or large cavity. After extractions are completed the remaining teeth are moved into position to create a proper arch form, functionally, and esthetically desirable outcome.
After the space is created, either by extractions or the use of a palatal expander, phase two of the orthodontic treatment can be started. Phase two consists of placement of brackets and orthodontic bands on teeth in order to move them into proper alignment.