Cone-beam CT evaluation of orthodontic treatment outcomes for multiple impacted maxillary anterior teeth

To evaluate the orthodontic outcomes of multiple impacted maxillary anterior teeth using cone-beam computed tomography (CBCT) and analyze the root and alveolar bone attachment following orthodontic traction.

Sixteen patients with multiple impacted maxillary anterior teeth treated at the Department of Orthodontics, Affiliated Stomatological Hospital of Guangxi Medical University between 2016 and 2020 were included. A total of 14 Impacted maxillary central incisors(IMCIs), 13 Impacted maxillary lateral incisors(IMLIs), and 16 Impacted maxillary canines(IMCs) were assessed. CBCT scans and three-dimensional reconstructions were performed immediately after treatment completion. Measurements included root length(RL), intraosseous root ratio, alveolar bone loss of labial, lingual side(LaBL, LiBL), apical alveolar bone thickness(ABT) , and labial, lingual alveolar bone thickness(LaABT, LiABT) of impacted teeth compared to their contralateral counterparts. Statistical analysis was conducted to assess differences.

The RL and intraosseous root ratio of IMCIs and IMLIs were significantly smaller than those of the control teeth (p < 0.05). No statistically significant difference was observed in RL between IMCs and controls (p > 0.05), but the intraosseous root ratio was smaller in IMCs (p < 0.05). IMCIs exhibited greater LaBL (p < 0.05) and thinner LaABT (p < 0.05) compared to controls, while LiABT, LiBL or ABT showed no significant differences (p > 0.05). IMLIs had larger LiBL (p < 0.05), but LaBL, LiABT, LaABT or ABT did not differ significantly (p > 0.05). IMCs demonstrated greater LaBL (p < 0.05), with no significant differences in LaABT, LiABT, LiBL or ABT (p > 0.05). The success rates of orthodontic traction were 71.43% for IMCIs, 84.62% for IMLIs, and 93.75% for IMCs.

Orthodontic traction facilitates the preservation of multiple impacted maxillary anterior teeth, though post-traction alveolar bone attachment remains suboptimal. Among the impacted teeth, canines exhibit superior root development and higher traction success rates.