Department of Oral and Maxillofacial Diseases, University of Helsinki, P.O. Box 41, 00014, Helsinki, Finland.
Institute of Dentistry, University of Turku, Turku, Finland.
Clin Oral Investig. 2020 Feb;24(2):897-905. doi: 10.1007/s00784-019-02904-1. Epub 2019 Jun 24.
In children and adolescents, cone-beam computed tomography (CBCT) is frequently used for localization of unerupted or impacted teeth in the anterior maxilla. CBCT causes a higher radiation dose than conventional intraoral and panoramic imaging. The objective was to analyze the location of impacted canines in a three-dimensional coordinate and thereby optimize the CBCT field-of-view (FOV), for radiation dose reduction.
Location of 50 impacted maxillary canines of children under 17 years was retrospectively evaluated from CBCT scans. The minimum and maximum distances of any part of the right- and left-side canines to three anatomic reference planes were measured to assess the adequate size and position of a cylindrical image volume.
A cylinder sized 39.0 (diameter)×33.2 (height) mm, with its top situated 13.8 mm above the hard palate, its medial edge 8.4 mm across the midline, and anterior edge 2.5 mm in front of the labial surface of maxillary central incisors fitted all the analyzed canines.
In this sample, the FOV required for imaging maxillary impacted canines was smaller than the smallest FOV offered by common CBCT devices. We encourage development of indication-specific CBCT imaging programs and aids to facilitate optimum patient positioning.
An impacted maxillary canine is a common dental problem and a frequent indication for 3D imaging particularly in growing individuals. This article focuses on the optimization of CBCT of impacted canines. Our recommendation of a reduced FOV promotes radiation safety.
在儿童和青少年中，锥形束计算机断层扫描（CBCT）常用于定位上颌前部未萌出或埋伏的牙齿。CBCT 比传统的口内和全景成像产生更高的辐射剂量。本研究的目的是分析埋伏尖牙在三维坐标中的位置，从而优化 CBCT 的视野（FOV），以减少辐射剂量。
回顾性分析了 50 例 17 岁以下儿童的上颌埋伏尖牙的 CBCT 扫描结果。测量右侧和左侧尖牙的任何部位到三个解剖参考平面的最小和最大距离，以评估圆柱状图像体积的足够大小和位置。
直径为 39.0mm、高度为 33.2mm 的圆柱体，其顶部位于硬腭上方 13.8mm，内侧边缘横跨中线 8.4mm，前边缘位于上颌中切牙唇面前方 2.5mm，适合所有分析的尖牙。
在本样本中，用于成像上颌埋伏尖牙的 FOV 小于常见 CBCT 设备提供的最小 FOV。我们鼓励开发针对特定适应证的 CBCT 成像程序和辅助工具，以方便最佳的患者定位。
上颌埋伏尖牙是一种常见的牙科问题，也是三维成像的常见适应证，尤其是在生长发育中的个体。本文重点介绍了埋伏尖牙的 CBCT 优化。我们推荐使用较小的 FOV 以促进辐射安全。
