When this has been done a harmonious axial relationship, though not necessarily a constant one, can continue to exist throughout the remainder of the growing period. Figure 4 . Pretreatment and post treatment tracings superimposed on the palatal plane. There was no increase in anterior dental height but considerable growth at the condyles. A shows that mandibular incisors were excessively intruded and that the maxillary incisors were moderately intruded.
B shows the posttreatment reactions.
Note that the mandibular incisors again moved up and closed the bite accordingly. Merritt made a study of vertical overbite in 30 treated cases. Measurements were made before treatment, after treatment, and from two to three years posttreatment. Pretreatment and posttreatment tracings superimpose on the palatal plane. During treatment anterior detel hieght increased 14mm and has remained the same through 4 years of posttreatment observation.