[Orthodontic failures in Class II cases]

In Class II treatment, as with all malformations, therapeutic failure can impact some or all of our treatment aims, whether occlusal, functional or esthetic. Using clinical cases, we will first define the concept of failure and the limits of what is acceptable in these different areas. We will then attempt to determine the main causes underlying our failures in order to better avoid them. An analysis of the literature and of the clinical cases demonstrates that our failures are most often caused by a misevaluation of the amount and direction of residual growth, poor control of the vertical dimension, inadequate management of functional problems, an inadequate position of the maxillary and mandibular incisors. In addition to these major treatment errors, one also encounters insufficient patient cooperation, which needs to be assessed and maintained in order to limit the number of failures and treatment drop-outs.