Long-term stability of class II, Division 1, nonextraction cervical face-bow therapy .1. Model analysis

The long-term stability of Class II, Division 1 nonextraction therapy remains poorly described. This study evaluates the face-bow therapy, in conjunction with full-fixed appliance therapy, of 42 patients (34 females and 8 males) who were treated by the same practitioner. Treatment goals had been attained for all patients. The pretreatment, posttreatment, and postretention records were taken at 11.5, 14.5, and 23.1 years, respectively. The results showed that mandibular and maxillary arch widths were increased significantly during treatment. Mandibular intercanine width decreased 0.3 mm during the postretention period; the remaining width measures increased or remained stable. Arch length, which did not change during treatment, decreased 1.0 mm after treatment. Overjet and overbite decreased 4.4 mm and 2.5 mm, respectively, during treatment. Both overjet (0.5 mm) and overbite (0.4 mm) showed small increases after retention. Mandibular incisor irregularity was decreased 2.7 mm during treatment and increased only 0.4 mm after treatment. Within the limits of this study, it is concluded that, when the described techniques are used, nonextraction therapy for patients with Class II malocclusion is largely stable.