A comparison of the Ricketts and Tweed-type arch leveling techniques.

The purpose of this study was to compare the effectiveness and long-term stability of arch leveling and overbite correction carried out by the Ricketts and modified Tweed techniques. The sample comprised 60 Class II, deep bite, low-angle adolescent nonextraction cases, 30 each from the offices of Robert Ricketts and Fred Schudy, with cephalograms taken before and immediately after treatment and an average of more than 4 years after treatment. Both techniques were successful in overbite correction, producing only minimal increases in mandibular plane angle and anterior facial height. Mandibular incisors in the Ricketts group demonstrated more flaring and anterior bodily movement during treatment, with a greater amount of posttreatment uprighting and overbite relapse than the Schudy group. The Ricketts group demonstrated slightly more than 1 mm of true lower incisor intrusion; this change was relatively stable after treatment. Both techniques produced similar amounts of mandibular molar extrusion during treatment; these changes remained stable after treatment.