In traditional orthodontic treatments a common approach is to recommend pulling out some of the permanent (adult) teeth to make room in a crowded dental arch.  The most common teeth to be removed for orthodontic reasons are the four first bicuspids.  The dental arches are the bones that contain the teeth.  The upper arch is the maxilla and the lower arch is the mandible.  The balance between the tongue, cheeks and lips muscles forces are important for the development and the shape of the dental arches.  A complete adult dentition consists of 32 teeth.  Four incisors, two canines, four bicuspids and six molars on each dental arch.  Each one with a particular form and function, just like the rest of the parts of our body.
 

Research has shown that following bicuspid extractions on average the maxillary incisors are retracted 7 mm and the mandibular incisors are retracted 3.5 mm.  Retraction of teeth usually leads to unfavorable facial changes as a consequence and may contribute to detrimental Temporomandibular Joint effects.  Since pulling out teeth reduces the size of the dental arches,  the result is less space for the tongue.  Reduction of the tongue space could cause soft tissue dysfunction, like tongue thrust and incorrect resting tongue position, which eventually lead to orthodontic treatment relapse.  In addition, less space for the tongue in the mouth due to retraction of the dental arches could result in upper airway space reduction and therefore potential breathing problems,  as the tongue usually falls back towards the throat during sleep time.  Lower oxygen levels due to airway space reduction and dysfunctional breathing represents a threat for overall health.

An alternative to dental extractions is dental arch development.  With an adequate intra-oral appliance, we can improve the dental arch form, get enough room for the tongue and then easily align crooked teeth.  Also by correcting dysfunctional oral-facial patterns, dental arch development can be stimulated and orthodontic stability is better achieved.