Original article
Anchorage loss assessment of the indirect anchor tooth during adjunctive orthodontic treatment

https://doi.org/10.1016/j.ajodo.2018.04.027Get rights and content

Highlights

  • •

    The indirect anchor tooth moved about 0.9 mm.

  • •

    The indirect anchor tooth moved more in the mandible than in the maxilla.

  • •

    Occlusal change should be monitored when using indirect anchorage system.

Introduction

This study quantitatively assessed movement of anchor teeth connected to a miniscrew (indirect anchor tooth) and investigated factors affecting movement during adjunctive orthodontic treatment.

Methods

Dental plaster models of 28 patients whose treatment included an indirect anchor tooth on one side were collected before and after treatment. The casts were digitally scanned, and 2 groups were constituted: the indirect anchor teeth (experimental group; n = 52) and the untreated teeth (control group; the first and second premolars opposing the indirect anchor tooth to which no orthodontic force was applied; n = 55). Pretreatment and posttreatment models were superimposed and the amount and direction of indirect anchor tooth movement were evaluated with the use of a univariate linear mixed model. Possible factors affecting movement of the indirect anchor tooth and its significance were also evaluated with the use of a multiple linear mixed model.

Results

The indirect anchor tooth moved 0.91 ± 0.50 mm and did not exhibit significant differences in the transverse, vertical, or sagittal directions. The location of the indirect anchor tooth affected movement and the tooth moved significantly more in the mandible than in the maxilla.

Conclusions

The indirect anchor tooth can move during adjunctive orthodontic treatment and thus requires careful monitoring for occlusal changes.

Section snippets

Material and methods

We retrospectively selected 28 patients (15 men and 13 women) who visited the Department of Orthodontics at Gangnam Severance Dental Hospital from May 2007 to February 2013 and underwent adjunctive orthodontic treatment with the use of an indirect anchorage system for various reasons. The mean age was 29.9 years (male 28.2 years, female 31.4 years) and the mean treatment duration was 1.1 years (male 1.2 years, female 1.0 years), as seen in Table I. The adjunctive treatment included molar

Results

The movement was measured for each individual anchor tooth, regardless of how many indirect anchor teeth were engaged. The mean (±SD) amount of movement was 0.91 (±0.50) mm in the experimental group, which was significantly larger than that in the control group movement of 0.34 (±0.19) mm (P < 0.001; Table III). The experimental group moved 0.41-0.50 mm in the transverse, vertical, and sagittal planes, and the control group moved approximately 0.09-0.22 mm in each plane. The comparison between

Discussion

The miniscrew as a direct anchorage system is considered to be reliable by both orthodontists and patients for various orthodontic cases.13, 14 However, secondary displacement of the miniscrew of ∼0.2-1.1 mm was reported during orthodontic treatment. The insertion site, loading duration, and length of the miniscrew were factors affecting its displacement.5, 6, 15

Compared with the multitude of studies on the stability of miniscrews themselves, there have only been a few studies that evaluate the

Conclusion

An indirect anchorage system can be used effectively in adjunctive orthodontic treatment. However, careful monitoring of changes in occlusion is required because just less than 1 mm of movement of the indirect anchor tooth is anticipated, especially in the mandible.

References (32)

  • S. Singh et al.

    Three-dimensional finite element analysis of strength, stability, and stress distribution in orthodontic anchorage: a conical, self-drilling miniscrew implant system

    Am J Orthod Dentofacial Orthop

    (2012)
  • G. Lemieux et al.

    Precision and accuracy of suggested maxillary and mandibular landmarks with cone-beam computed tomography for regional superimpositions: an in vitro study

    Am J Orthod Dentofacial Orthop

    (2016)
  • B.R. Hoggan et al.

    The use of palatal rugae for the assessment of anteroposterior tooth movements

    Am J Orthod Dentofacial Orthop

    (2001)
  • N.C. Choi et al.

    Treatment of class II protrusion with severe crowding using indirect miniscrew anchorage

    Angle Orthod

    (2007)
  • F. Celenza

    Implant-enhanced tooth movement: indirect absolute anchorage

    Int J Periodontics Restorative Dent

    (2003)
  • M. Nienkemper et al.

    Systematic review of mini-implant displacement under orthodontic loading

    Int J Oral Sci

    (2014)

    • Cited by (8)

    View all citing articles on Scopus

    All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest, and none were reported.

    View full text
    © 2018 by the American Association of Orthodontists. All rights reserved.