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Updated: Jan 14, 2026
Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment
Published on: February 23, 2024
Factors of Alveolar Bone Changes Around Maxillary Central Incisors in Extraction Orthodontic Cases With Clear Aligner
Xuan Luo1, Yishan Zhang1, Siwei Zhang1
1State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
Objective:
To evaluate the related factors for alveolar bone changes surrounding maxillary central incisors in extraction cases with clear aligner therapy, including tooth displacement and movement pattern.
Materials And Methods:
A total of 94 patients were included. Pre-treatment (T0) and post treatment (T1) cone beam computed tomography was obtained to calculate tooth displacement and labial bone thickness (LBT), palatal bone thickness (PBT), labial bone height (LBH) and palatal bone height (PBH) at different root levels. Paired-t test and Wilcoxon signed-rank test were performed to compare tooth movement and bone changes between T0 and T1. The two-sided Welch's t-test and Mann-Whitney U test were applied for comparison between movement patterns. Multiple linear regression with backward elimination was used to investigate possible factors related to bone changes.
Results:
Defect of palatal bone was significant, while labial bone basically maintained. Different bone dimensional changes were found between uncontrolled tipping and controlled tipping. Tooth retraction was associated with the decrease of PBT and the increase of LBT. Crown retraction was a dominant factor related to the reduction of PBH. Incisor intrusion resulted in the increase of PBT, the decrease of LBT and the bone defect of both LBH and PBH. Root distal movement was associated with the resorption of LBT and LBH. Lingual inclination was evidently related to LBT loss.
Conclusion:
Three-dimensional tooth displacements and movement pattern acted as risk factors for maxillary anterior bone changes after retraction. Treatment planning deign should be aware of predicted tooth movement, preventing alveolar bone defect.
Trial Registration:
Clinical Study Registration Number: HGGC-227.
