Interseptal bone reduction on the rate of maxillary canine retraction

Abstract

Objective: To propose and evaluate a novel surgical approach with minimal trauma, termed interseptal bone reduction, combined with the use of a conventional orthodontic fixed appliance to accelerate canine retraction.

Materials and methods: A split-mouth design study was conducted in 18 female subjects (mean age, 21.9 years) whose bilateral upper first premolars were extracted and who subsequently received canine distalization. The extraction socket on the experimental side was deepened, and interseptal bone distal to the maxillary canine was reduced in thickness using a surgical bur; conventional extraction was performed on the control side. The canines were then distalized using elastomeric chains on both the labial and palatal sides, with a net force of 150 g. The extent of canine movement and rotation was determined from study models, and the angulation was analyzed based on lateral cephalograms.

Results: A Wilcoxon signed rank test demonstrated that the extent of canine movement in the mesio-distal direction after 3 months was significantly greater on the experimental side than on the control side (5.4 and 3.4 mm, respectively, P = .002). However, there was no statistically significant difference in canine angulation or rotation after 3 months between the experimental and control sides.

Conclusions: In combination with the use of conventional orthodontic appliances, interseptal bone reduction can enhance the rate of canine movement when interseptal bone is sufficiently reduced in both thickness and depth following surgical criteria.

Keywords: Accelerated tooth movement; Mini-implant; Optimum force; RAP; Surgical approach.

Figure 1.

Position of the surgical guide wire, as shown intraorally.

Figure 2.

Interseptal bone reduction technique: Dashed lines indicate the areas of interseptal bone reduction.

Figure 3.

Periapical radiographs before (A) and after (B) extraction and interseptal reduction.

Figure 4.

Mechanics used for canine distalization.

Figure 5.

Angulation-indicating wires on the canine brackets.

Figure 6.

Example of a case between the experimental (right) and control (left) sides: canine retraction was complete within 3 months. (A) Before; (B) After.

Figure 7.

The average extent of canine movement (mean ± standard deviation [SD], * P  =  .002).

Figure 8.

The average accumulated extent of canine movement (mm) ± standard deviation (SD) on the experimental side and control side (T1 and T3; P  =  .002, T2; P =  .003).