Enabling and restricting functions of the overjet in orthodontic treatment.

The aim is to evaluate the functions of the overjet in mediating, aggravating, and enabling the expression of jaw growth in growing patients with Class II division 1 and Class III malocclusions. Beside malocclusion severity and treatment timing, treatment duration warrants special consideration, contrasting shorter-term (2-3 years) and longer-term (5-7 years) responders to treatment, both encompassing the contribution of the adolescent growth spurt. Analysis of the genetic and environmental components affecting the development of malocclusion and growth modification indicates that varying critical periods of growth among the craniofacial components account for the variable individual responses to treatment. Clinical implications include keeping the overjet off the path of mandibular horizontal movement during orthopedic treatment, recognizing gender differences in the potential response to treatment, and assessing the value of longer treatment in slow responders. [ABSTRACT FROM AUTHOR]