Class II subdivision treatment with the Forsus Fatigue Resistant Device vs intermaxillary elastics

Abstract

Objective: To compare the effectiveness of comprehensive fixed appliance treatments implemented in combination with Forsus or intermaxillary elastics in Class II subdivision subjects.

Materials and methods: Twenty-eight Class II subdivision patients were allocated to two groups using matched randomization: Forsus group (mean age, 14.19 ± 1.02 years) and elastics group (mean age, 13.75 ± 1.16 years). Patients received fixed appliance therapy in combination with either Forsus or intermaxillary elastics. The study was conducted on lateral cephalograms and digital models acquired before orthodontic treatment and 10-12 weeks after the fixed appliances were removed.

Results: The treatment phase comprising the use of Forsus (4.53 ± 0.91 months) was significantly shorter compared with elastics application (6.85 ± 1.08 months). This was also true for comparing duration of overall comprehensive treatment in both groups. Extrusion and palatal tipping of maxillary incisors and clockwise rotation of the occlusal plane were greater in the elastics group (P < .05). The mandibular incisors were proclined in both groups (P < .001), but no significant difference was observed between groups (P > .05). The mandibular incisors showed intrusion in the Forsus group and extrusion in the elastics group; the difference between groups was significant (P < .05). Overbite was decreased in both groups (P < .001) in similar amounts. Improvement in overjet, mandibular midline deviation, and correction of molar relationship on the Class II side were greater in the Forsus group (P < .05).

Conclusion: Forsus is more effective for correcting Class II subdivision malocclusion in a shorter treatment period with minimal patient compliance required.

Keywords: Class II subdivision; Fixed functional appliance; Intermaxillary elastics.

Figure 1.

Application of elastics on (A) Class II side and (B) Class I side.

Figure 2.

Application of Forsus on (A) Class II side and (B) Class I side.

Figure 3.

Skeletal and dental cephalometric measurements: (1) SNA angle; (2) SNB angle; (3) ANB angle; (4) SN-GoGn angle; (5) U1-SN angle; (6) U1 vertical; (7) IMPA; (8) L1 vertical; (9) U6-horizontal; (10) U6-PP angle; (11) U6-vertical; (12) SN-occlusal plane angle.