Treatment of Palatally Displaced Canines Using Miniscrews for Direct or Indirect Anchorage: A Three-Dimensional Prospective Cohort Study on Tooth Movement Speed

Abstract

Palatally impacted canines are usually challenging to treat in terms of both biomechanics and possible side effects. Different therapeutic approaches have been reported with or without the use of temporary anchorage devices, including the canine-first approach. Two groups of patients with palatally impacted canines were compared, observing their canine movement measured on consecutive CBCTs after three months of treatment. In the control group, impacted canines were treated with direct anchorage on miniscrews, and in the test group with indirect anchorage using a miniscrew-supported transpalatal arch. The primary outcome was the canine movement speed; the secondary outcome was the change in the root length of adjacent teeth. The median monthly apex speed was 1.05 mm in the control group (IR [0.74, 1.64]) and 0.72 mm in the test group (IR [0.27, 1.30]). The median monthly cusp displacement was 1.89 mm in the control group (IR [1.04, 2.84]) and 1.08 mm in the test group (IR [0.81, 1.91]). Approximately 50% of teeth adjacent to an impacted canine underwent a negative root length change of less than 1 mm in the majority of cases, but no significant differences were found in root length changes between groups. No statistically significant differences in the reported speeds were found, and no miniscrew failures were observed in either group.

Orthodontic Treatment of Palatally Impacted Canines in Severe Non-Syndromic Oligodontia with the Use of Mini-Implants: A Case Report

“…Therefore, the additional MI was placed in the palatal suture and used first as direct and subsequently as indirect anchorage for the buccal movement of the left upper canine. Such indirect anchorage is not a preferable option since it means that the traction of the PDC could generate collateral forces on the teeth connected with the MI [21]. A significant widening of the periodontal space of the upper left premolar was detected on the control panoramic X-ray.…”

“…Currently, temporary anchorage devices such as orthodontic mini-implants (MIs) serve to circumvent this limitation. MIs may be used both as direct and indirect anchorage [21]. Direct anchorage means that the force is placed directly to the MI, while in indirect anchorage, the MI is bonded with the teeth to avoid unwanted movement due to the reciprocal orthodontic forces.…”

Canine Impaction: Digital Orthodontic Planning in Conjunction with TADs (Temporary Anchorage Devices) and Aligners

“…The "Canine First Approach" was proposed to avoid these side effects related to the incorrect canine traction, including root resorption and insufficient tooth movements. According to the study by Migliorati et al, by using the direct anchorage, the canine showed a 1 mm/month movement speed rate for the root apex and slightly faster movement in terms of cusp movement when compared to the use of the indirect [19,20]. The single-TAD approach is impressive and simple to handle, but it should be noted that some authors prefer the use of two-TAD technique to reduce any stability problems due to traction activation [21][22][23].…”

Biomechanical Effects of Different Auxiliary–Aligner Designs on the Rotation of an Upper Canine: A Finite Element Analysis of a Specific Patient

“…A skeletal III class with a bi-retrusion and a brachi-facial growth pattern resulted from the cephalometric EBO analysis results (Table 1). In this patient, the treatment plan needed to provide the recovery of the impacted canine: the first step was surgical exposure of the canine crown, then the canine was pulled through a Temporary Anchorage Device (TAD) [24,25]. At first, the canine was surgically exposed then, a miniscrew OrthoEasy ® (FORESTADENT Bernhard Förster GmbH, Pforzheim, Germany) 10 × 1.7 mm was inserted from the palatal side between 1.5 and 1.6, and a Titanium Molibdenum Alloy (TMA) rectangular wire (0.019 × 0.025) was used to shape a lever activated to pull the palatal canine (Figure 3).…”