Fractured, hypoplastic, grossly carious teeth, root canal treated teeth and teeth with large restorations are preferred for extraction over healthy teeth.
The main consideration is the long-term prognosis for the tooth rather than the appearance. Grossly malpositioned teeth which are difficult to align may often be the teeth of choice for extraction.
The position of the apex of the tooth must be considered as it is more difficult to move the apex than the crown.
Crowding in one part of the arch is more readily corrected if extractions are done in that part rather than a remote area of the arch.
However, incisor crowding is usually relieved by premolar extraction as it gives a more pleasing appearance and occlusal balance than with incisor extraction.
The first premolar, positioned in the center of each quadrant, is usually near the area of crowding whether in the anterior or buccal segment.
Hence, it is also the tooth most frequently extracted along with orthodontic treatment.
TYPES OF EXTRACTION PROCEDURES
Balancing Extractions
Balancing extractions may be defined as the removal of a tooth on the opposite side of the same arch (although not necessarily the same) in order to preserve symmetry.
If a tooth is removed from one side of the dental arch which is crowded, or which has complete contact of teeth all around, there is a tendency for the remaining teeth to move towards the extraction space. This is in the form of forward movement of teeth behind the space, or movement of anterior teeth across the center of the arch, resulting in asymmetry. It is usual to balance extractions in order to prevent such asymmetry.
INVISIBLE ORTHODONTICS: Configuration and biomechanical analysis of attachments. A narrative review
Compensating Extractions
Removal of the equivalent tooth in the opposing arch to maintain buccal occlusion. In some Class I crowding cases, it is necessary to extract in both arches to maintain lateral symmetry. Compensating extractions preserve interarch relationship by allowing the posterior teeth to drift forward together.
Enforced Extractions
These extractions are carried out because they are necessary as in the case of grossly decayed teeth, poor periodontal status, fractured tooth, impacted tooth, etc.
