Jiangsu Key Laboratory of Oral Diseases, and Department of Orthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
Jiangsu Key Laboratory of Oral Diseases, Engineering Center for Digital Medical Technology of Stomatology, Nanjing Medical University, Nanjing, China.
Am J Orthod Dentofacial Orthop. 2021 Feb;159(2):167-174. doi: 10.1016/j.ajodo.2019.12.019. Epub 2020 Dec 18.
This research aimed to analyze the prevalence of root dilaceration in buccally impacted canines (BICs) and palatally impacted canines (PICs) with their adjacent teeth based on a retrospective cone-beam computed tomography (CBCT) investigation.
Pretreatment CBCT images of 145 subjects with unilateral maxillary canine impaction and 145 age- and sex-matched subjects without impaction were used. Prevalence of dilaceration (subclassified to root curvature and apical hook based on severity) in canines and adjacent teeth was determined in CBCT records. The root length of maxillary impacted canines was measured for further morphologic evaluations.
Impacted canines had a significantly higher prevalence of root dilaceration than the control group and compared with the erupted contralateral canines in the experimental group (P < 0.001 for both). A significantly higher prevalence of root dilaceration was found in adjacent lateral incisors of the PICs subgroup than that of the control group (P < 0.001). Adjacent premolars had a higher prevalence of dilacerated roots in the PICs subgroup (P < 0.001) than the control group, but not for the BICs subgroup. Significantly higher prevalence of curvature (P < 0.001 for both) and hook (P = 0.008 and P < 0.001, respectively) were found in BICs and PICs roots compared with the control group. Both types of impacted canines had significantly shorter roots than the control group (P < 0.001 for both).
BICs and PICs have a higher tendency to present root dilaceration and shorter roots. Unlike BICs, adjacent teeth to PICs were more frequently observed to have root dilaceration.
本研究旨在通过回顾性锥形束 CT（CBCT）研究分析颊侧埋伏尖牙（BICs）和腭侧埋伏尖牙（PICs）及其相邻牙齿的根裂发生率。
使用 145 例单侧上颌尖牙埋伏患者和 145 例年龄和性别匹配的无埋伏患者的治疗前 CBCT 图像。在 CBCT 记录中确定尖牙和相邻牙齿的根裂（根据严重程度分为根弯曲和根尖钩）发生率。测量上颌埋伏尖牙的根长以进行进一步的形态学评估。
埋伏尖牙的根裂发生率明显高于对照组，且实验组中未萌出的对侧尖牙也明显高于对照组（均 P < 0.001）。PICs 亚组中相邻侧切牙的根裂发生率明显高于对照组（P < 0.001）。PICs 亚组中相邻前磨牙的根裂发生率高于对照组（P < 0.001），但 BICs 亚组无此差异。BICs 和 PICs 的根弯曲（均 P < 0.001）和根尖钩（分别为 P = 0.008 和 P < 0.001）的发生率明显高于对照组。两种类型的埋伏尖牙的根都明显短于对照组（均 P < 0.001）。
BICs 和 PICs 更倾向于出现根裂和更短的根。与 BICs 不同，PICs 的相邻牙齿更常出现根裂。
