The most common extraction pattern in orthodontic patients with crowding of the teeth is the four first bicuspids. This is usually done in cases with severe crowding or bimaxillary protrusion. In some instances, orthodontists have decided, instead of extracting the first bicuspids, to extract the second bicuspids, for various reasons that we shall discuss in this review. Several other extraction patterns have also been implemented in the past, including second molars, lower incisors, and even asymmetric extractions. In this review, we shall discuss the pros and cons of each of these choices. In some patients, clinicians have even decided to extract the upper first- and lower-second bicuspids because the patient had a Class II malocclusion. It was incorrectly assumed that a Class I molar occlusion is better than a Class II molar relationship. Another typical extraction pattern frequently used in cases with Class II occlusion and a good lower arch is to extract only the maxillary first bicuspids. This may be appropriate in cases of Class II occlusion with no crowding in the lower arch, but timing is essential. The frequency of extractions has varied over time, ranging from as low as 10% to as high as 50%. This was all in an effort to achieve greater long-term stability in the treatment results. We shall review several factors, in addition to crowding, that should be considered when deciding on extractions. These include the facial morphology, mandibular growth pattern, and stage of maturation. We shall finally show clinical examples that address some of these challenges.
Ib Leth Nielsen (Sun,) studied this question.