Corticotomy-assisted application of different miniplates and intermaxillary elastics : Comparison of the effectiveness after growth spurt in individuals with skeletal class III malocclusion.

PURPOSE: This prospective randomized clinical study aimed to evaluate the effectiveness of maxillary protraction with differently located miniplates combined with intermaxillary elastic applications after corticotomy in patients with skeletal class III malocclusion.

METHODS

Twenty patients aged 13-15 years were randomly assigned to one of three groups using a computer-generated random sequence. In the AS and MS groups, an acrylic splint (AS) with hooks in the upper molar region was cemented; the MS group additionally received two palatal miniscrews (MS) for anchorage. In all patients, incomplete Le Fort I osteotomy was performed. Miniplates were placed vertically between the mandibular canine and first premolar in all groups, and horizontally under the osteotomy line in the MP group. Class III elastics were applied 5 days postsurgery and continued until a positive overjet was achieved. Cephalometric radiographs were taken at the beginning of treatment (T0) and at the end of the protraction period (T1).

RESULTS

The MP group exhibited the greatest maxillary advancement (3.2 ± 2.2 mm, p < 0.05). Significant B‑point changes occurred in the MP (-1.2 ± 1 mm, p < 0.05) and AS (-0.9 ± 0.9 mm, p < 0.05) groups. The AS group had the largest increase in upper incisor angulation (U1-SN: 5.5° ± 2.5; U1-PP: 4.7° ± 3.3, p < 0.05). All groups showed favorable soft tissue changes; in the MS group the best control of mandibular clockwise rotation was achieved. The duration of protraction period was 5.52 ± 0.9 months for the MP group, 4.84 ± 1.3 months for the AS group, and 4.74 ± 1.18 months for the MS group.

CONCLUSION

Although significant improvement was observed in maxillomandibular relations in all groups, the greatest change was observed in the MP group (p < 0.01). The use of skeletal anchorage helped reduce dentoalveolar changes. The MS group was most successful in controlling clockwise rotation of the mandible.