Dentoskeletal effects of the cast-splint Herbst, twin-block, and twin-force bite corrector devices used to correct class II malocclusion : Three-year follow-up.

PURPOSE: This retrospective observational study aimed to evaluate the stability of dentoskeletal changes in skeletal class II division 1 with removable and fixed functional orthopedic appliances followed by fixed orthodontic appliances over a follow-up period of 3 years.

METHODS

We included lateral cephalograms of 42 individuals who had undergone orthodontic treatment with functional jaw orthopedic appliances followed by fixed orthodontic appliances and 7 individuals who did not receive any treatment. Measurements were obtained at the start of treatment (T0) and at the end of treatment (T1) and at 3 years follow-up (T3). Participants were divided into three equal groups based on the used appliance: cast-splint Herbst (CSH), twin-block (TWB), and twin-force bite corrector (TFBC). Cephalometric assessments were performed using NemoCeph software (Nemotec, Madrid, Spain).

RESULTS

The total follow-up period of all individuals included in the study was 39.12 ± 7.64 months after the end of the fixed orthodontic treatment. The groups differed significantly in changes in the cephalometric parameters Co-Gn, Co-Go, Co‑A, Wits appraisal, overbite, overjet, and lower lip‑E line parameters during the follow-up period. The parameters Co-Gn, Co-Go, and Co‑A in the control group increased significantly more than in the treatment groups. While the increase in overjet and overbite was significantly higher in the treatment groups compared to the control group, the regression in the lower lip‑E line was observed to decrease (except for the TFBC group).

CONCLUSION

Orthodontic treatment performed by applying fixed appliances after the first phase of functional jaw orthopedics can be considered stable for a 3-year follow-up period. Soft tissue changes were more common than those in the area of the skeletal structures. The observed skeletal effect of the TFBC appliance was less than that of the other two treatment devices.