Interception by definition means "to stop, deflect, or interrupt the progress or intended course." The objective of interceptive orthodontic supervision is to create a more normal dentofacial environment as early as possible to prevent the adaptations and limitations that are often associated with a significant malocclusion in late adolescence. The question is not "what can be treated early?" but rather "what shotdd be treated early?" There are hidden pitfalls associated with interceptive treatment that may include long treatment times, maintenance of appliances, inability to accurately anticipate the changes associated with dentofacial growth and development, and the necessity to closely monitor treatment progress to avoid irreversible occlusal changes while evaluating the treatment response. The clinician must be prepared to evaluate and to alter the original plan of treatment if patient response is not coincident with treat" ment objectives. Problem list and treatment plan development in the young patient is demanding as there are many variables to consider, many of which are difficult to predict or control. The clinician must have an understanding of the dentofacial changes associated with various growth patterns to identify the cause of the malocclusion, to determine treatment objectives and options, and to select the appropriate appliance to reach those objectives. One goal of early intervention should be the prevention of progressive, irreversible soft iissue or bony changes. In developing arch length deficiency malocclusions, for instance, serial extraction procedures, guidance of eruption, or active appliance therapy can be instituted early to create or to preserve arch length with' the objective of encouraging the dentition to erupt into a more ideal arch form. There is evidence, for instance, to suggest that teeth that erupt ectopically, out of attached gingival tissue, will exhibit long-term decreases in both attached tissue thickness and alveolar bone height when compared with normally erupting controls. Another example of a potentially progressive change is a functional mandibular deviation from rest