METHODS: Retrospective CBCT data taken before and after maxillary anterior retraction in 36 patients were used in this study. The incisive canal length (ICL), maxillary central incisor length (TL), angles between the palatal plane and axes of the maxillary alveolar border (θ1), IC (θ2), and maxillary central incisor (θ3), retraction distance (TDE), distance from the maxillary central incisors to the IC (D), cross-sectional area of the IC (CSA), and volume of the IC were evaluated. Comparison of the parameters between contact and noncontact groups were examined. Logistic regression was performed to analyze the probable outcome prediction.
RESULTS: All parameters significantly decreased after anterior retraction, except for the ICL. Eighteen roots in 12 patients contacted the IC. The θ1, θ2, θ3, and D values at all levels were significantly lower, whereas the TDE, midlevel and oral opening CSA, and volume were significantly higher in the contact group compared with the noncontact group. The larger the pretreatment θ1 and θ3 were, the higher was the chance of incisors not contacting the IC.
CONCLUSIONS: Maxillary central incisors not contacting the IC after anterior retraction was positively associated with larger degrees of pretreatment maxillary alveolar bone angle and maxillary central incisor angle.
方法:本研究使用了36例患者上颌前退缩前后的CBCT数据。
结果:前回缩后所有参数均显着降低,
结论:上颌中切牙前缩后未接触IC与上颌牙槽骨角和上颌中切牙角预处理程度较大呈正相关。