Deciding whether or not to extract permanent teeth is probably the one aspect of orthodontic practice that has stirred up the most debate. For more than a century, opposing groups of clinicians have disagreed as to whether it is sometimes necessary to extract or if it is always possible to develop the arches in order to avoid extractions. Besides a laudable desire to spare our patients the trauma and cost of extractions, and the wish to save their permanent teeth, the controversy concerns the supposed consequences of these extractions. Detractors argue that they would be, among other reasons, a contributing factor to the development or worsening of dysfunctional disorders of the masticatory apparatus (TMD) or obstructive sleep apnea-hypopnea syndrome (OSAHS), and of deleterious effects on the esthetics of the profile and of the smile.