Angle Orthod. 2018 Jul;88(4):384-389. doi: 10.2319/103117-739.1. Epub 2018 Mar 21.
To determine the usefulness of panoramic radiographs in determining the labio-palatal position of maxillary impacted canines (MICs) and root resorption of permanent incisors on cone-beam computed tomography (CBCT) in correlation with the mesiodistal position of MICs on panoramic radiographs.
This retrospective radiographic study reviewed 64 patients with 86 MICs. Subjects were divided into two groups: group I (<15 years old) and group II (>15 years old). The mesiodistal position of the MICs' cusp tips was classified into five sectors on panoramic radiographs. The labio-palatal position of the MICs and root resorption of permanent incisors were evaluated on CBCT. The statistical correlation between panoramic radiograph and CBCT results was examined using the chi-square test and the Fisher exact test.
Most of the positions of MICs were palatal (67%), followed by labial (28%) and mid-alveolus (5%; P < .05). Labial positioned MICs on CBCT were more frequent in panoramic sector 1, mid-alveolus MICs were more common in sector 2, and palatally positioned MICs were more frequent in sectors 3, 4, and 5. The association between sectors of the MICs on panoramic images and the labio-palatal position of the MICs on CBCT was statistically significant ( P < .001). Root resorption of adjacent incisors showed a significant difference according to sector location ( P < .01) and was mainly found in sectors 4 and 5.
This study showed that the labio-palatal position of MICs and resorption of permanent incisors might be predicted using sector location on panoramic radiographs.
通过与全景片上上颌埋伏尖牙(MICs)的近远中位置相关联,确定曲面体层片(CBCT)在确定上颌埋伏尖牙的唇腭向位置和恒牙牙根吸收方面的作用。
本回顾性放射学研究共纳入 64 名患者的 86 颗 MICs。将患者分为两组:I 组(<15 岁)和 II 组(>15 岁)。在全景片上,将 MICs 的牙尖近远中位置分为五个区。在 CBCT 上评估 MICs 的唇腭向位置和恒牙牙根吸收情况。使用卡方检验和 Fisher 确切概率法检验全景片和 CBCT 结果之间的统计学相关性。
大多数 MICs 的位置为腭侧(67%),其次为唇侧(28%)和牙槽中(5%;P<.05)。CBCT 上的唇侧 MICs 在全景片的 1 区更为常见,牙槽中 MICs 在 2 区更为常见,而腭侧 MICs 在 3、4 和 5 区更为常见。全景片上 MICs 区与 CBCT 上 MICs 的唇腭向位置之间存在显著关联(P<.001)。根据区位置,邻牙牙根吸收存在显著差异(P<.01),主要发生在 4 区和 5 区。
本研究表明,可通过全景片上的区位置预测 MICs 的唇腭向位置和恒牙牙根吸收情况。