Recovery Growth of the Mandible After Chin Cup Therapy: Fact or Fiction

Chin cup therapy has shown growth retardation of the mandible at the condyles during the initial stage of treatment (first 2 to 3 years) and significant changes in the skeletal profile. However, little is known about whether or not those effects can be maintained until growth terminates. This article discusses the possible reaction of mandibular growth at the condyle during and after chin cup therapy. It was hypothesized that growth retardation occurs only during the initial stage of chin cup therapy and then condylar cartilage may gradually become accustomed to the chin cup force during therapy, allowing its growth activity to return to its original level. Furthermore, it was also thought that release of the chin cup force from the condylar cartilage, if done before growth completion, stimulated and accelerated growth. Growth taking place in such a manner was called “recovery growth.” It was also considered that recovery growth seemed to take place as long as there was growth potential left to recover the size of the mandible that was predetermined morphogenetically. Recovery growth might cause recurrence of the prognathic face and Class III malocclusion after chin cup use. It was suggested that the chin cup, as a rule, should be used until facial growth was complete to avoid recurrence of such Class III problems.