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Randomized Controlled Trial
. 2018 Jan;88(1):20-26.
doi: 10.2319/06417-424R. Epub 2017 Oct 6.

A comparative study of the effect of the intrusion arch and straight wire mechanics on incisor root resorption: A randomized, controlled trial

Marcio Rodrigues de Almeida, Aline Siqueira Butzke Marçal, Thais Maria Freire Fernandes, Juliana Brito Vasconcelos, Renato Rodrigues de Almeida, Ravindra Nanda
Randomized Controlled Trial

A comparative study of the effect of the intrusion arch and straight wire mechanics on incisor root resorption: A randomized, controlled trial

Marcio Rodrigues de Almeida et al. Angle Orthod. 2018 Jan.

Abstract

Objective: To analyze and compare external apical root resorption (EARR) of maxillary incisors treated by intrusion arch or continuous archwire mechanics.

Materials and methods: This cone-beam computed tomography (CBCT) study analyzed 28 deep bite patients in the permanent dentition who were randomly divided into two groups: Group 1, 12 patients with initial mean age of 15.1 ± 1.6 years and mean overbite of 4.6 ± 1.2 mm treated with the Connecticut intrusion arch (CIA) in the upper arch (Ortho Organizers, Carlsbad, Calif) for a mean period of 5.8 ± 1.27 months. Group 2, 16 patients with initial mean age of 22.1 ± 5.7 years and mean overbite of 4.1 ± 1.1 mm treated with conventional leveling and alignment using continuous archwire mechanics for 6.1 ± 0.81 months. The degree of EARR was detected in 112 maxillary incisors by using CBCT scans and a three-dimensional program (Dolphin 11.7, Dolphin Imaging & Management Solutions, Chatsworth, Calif). The CBCT scans were obtained before (T1) and 6 months after initiation of treatment (T2). Differences between and within groups were assessed by nonpaired and paired t-tests, respectively, with a 5% significance level.

Results: Significant differences were found for both groups between T1 and T2 ( P < .05) indicating that EARR occurred in both groups. However, there were no significant differences when EARR was compared between group 1 (-0.76 mm) and group 2 (-0.59 mm).

Conclusions: The Connecticut intrusion arch did not lead to greater EARR of maxillary incisors when compared with conventional orthodontic mechanics.

Keywords: Biomechanics; Intrusion; Overbite; Root resorption; Tomography.

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Figures

Figure 1
Figure 1
CONSORT flow diagram.
Figure 2
Figure 2
Connecticut intrusion arch.
Figure 3
Figure 3
Distance from apex to incisal edge.
Figure 4
Figure 4
Measurement of incisor vertical movement. A: centroid point; ANS: anterior nasal spine; PNS: posterior nasal spine.
See this image and copyright information in PMC

Comment in

  • Letters From Our Readers.
    Nascimento EHL, Freitas DQ. Nascimento EHL, et al. Angle Orthod. 2019 Jan;89(1):163. doi: 10.2319/0003-3219-89.1.163. Angle Orthod. 2019. PMID: 30702940 Free PMC article. No abstract available.
  • Letters From Our Readers.
    de Almeida MR. de Almeida MR. Angle Orthod. 2019 Jan;89(1):164-165. doi: 10.2319/0003-3219-89.1.164. Angle Orthod. 2019. PMID: 30702941 Free PMC article. No abstract available.

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