Alveolar bone response to maxillary incisor retraction using stable skeletal structures as a reference

Abstract

Objectives To evaluate alveolar bone change in relation to root position change after maxillary incisor retraction via cone-beam computed tomography (CBCT) using stable skeletal structures as a reference. Materials and Methods A total of 17 subjects (age 24.7 ± 4.4 years) who required retraction of the maxillary incisors were included. Labial and palatal alveolar bone changes and root change were assessed from preretraction and 3 months postretraction CBCT images. The reference planes were based on stable skeletal structures. The Kruskal-Wallis test and Wilcoxon signed-rank test were used to compare changes within and between groups, as appropriate. Spearman rank correlations were used to identify the parameters that correlated with alveolar bone change. The significance level was set at .05. Results The labial alveolar bone change after maxillary incisor retraction was statistically significant (P < .05), and the bone remodeling/tooth movement (B/T) ratio was 1:1. However, the palatal bone remained unchanged (P > .05). The change in inclination was significantly related to labial alveolar bone change. Conclusions Using stable skeletal structures as a reference, the change in labial alveolar bone followed tooth movement in an almost 1:1 B/T ratio. Palatal alveolar bone did not remodel following maxillary incisor retraction. The change in inclination was associated with alveolar bone change.

Morphometric and volumetric analysis of the proximity between the incisive canal and maxillary central incisors during anterior retraction: a retrospective cone-beam computed tomography study

“…10 Several studies evaluated the maxillary incisors and surrounding structures by superimposition of pre-and postretraction CBCT images. 9,11,12 However, the analysis of morphometric and volumetric measurements of the proximity between the IC and maxillary central incisors after maxillary anterior tooth retraction remains inconclusive.…”

Cone‐beam computed tomography assessment of maxillary anterior alveolar bone remodelling in extraction and non‐extraction orthodontic cases using stable extra‐alveolar reference

“…On Dolphin Imaging, CBCT files were oriented to the reference planes as described by Eskriwong and Thongudomporn 24 : sagittal – palatal plane (ANS‐PNS), coronal – most inferior points of the nasal floor, and axial – mid‐palatal suture. Lateral cephalograms were then extracted at both T1 and T2 for each patient and traced; the cephalometric measurements were recorded to compare pre‐ and post‐treatment skeletal and dental changes.…”

“…A couple of studies investigated cortical positional changes using stable external structures 24,25 and found the labial cortex resorbing with incisor retraction while the palatal cortex remained unchanged. Using an extra‐alveolar stable structure as reference would circumvent the potential errors found with the tooth axis, which changes as the incisor invariably tips when retracted 24 . Currently, a conclusion has not been reached regarding tooth movement and its responding alveolar cortical remodelling despite the advancement in imaging technology due to insufficient data and variability in measurement methodology.…”

“…[15][16][17]19,20 Recent systematic reviews and meta-analysis highlighted the low quality of currently available evidence published in English in extraction cases and the lack of non-extraction data. [21][22][23] A couple of studies investigated cortical positional changes using stable external structures 24,25 and found the labial cortex resorbing with incisor retraction while the palatal cortex remained unchanged. Using an extra-alveolar stable structure as reference would circumvent the potential errors found with the tooth axis, which changes as the incisor invariably tips when retracted.…”

“…Using an extra-alveolar stable structure as reference would circumvent the potential errors found with the tooth axis, which changes as the incisor invariably tips when retracted. 24 Currently, a conclusion has not been reached regarding tooth movement and its responding alveolar cortical remodelling despite the advancement in imaging technology due to insufficient data and variability in measurement methodology.…”