Division of Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China.
Department of Oral Health & Medicine, University Center for Dental Medicine Basel UZB, University of Basel, Basel, Switzerland.
Clin Oral Investig. 2024 Nov 19;28(12):647. doi: 10.1007/s00784-024-06022-5.
This randomised clinical study aimed to assess the influence of low-dose cone-beam computed tomography (CBCT) on the visibility of the mandibular canal (MC) and its proximity to mandibular third molars (M3Ms) as assessed by general dental practitioners (GPs) and oral-maxillofacial surgeons (OMFSs), as well as its impact on their clinical decisions, when compared to standard-dose CBCT.
154 impacted M3Ms from 90 patients were randomly assigned to three groups for two CBCT exposures using one standard-dose (333 mGy×cm) and one of the three investigated low-dose (78-131 mGy×cm) protocols. Blinded assessments of the MC visibility, M3M-MC proximity, surgical approach, crown/root sectioning, and referral decisions, were made by GPs and OMFSs on the images separately. Pairwise comparisons for MC visibility between paired scans were evaluated using Wilcoxon signed rank test, followed by a non-inferiority test with non-inferiority margin of 0.5 on a four-point scale. Differences in other variables between paired scans were evaluated using Wilcoxon signed-rank or McNemar tests.
The majority (78.5-99.3%) of MCs were clearly identified on standard-dose CBCT by all observers. Pairwise comparisons showed significant differences between paired scans only in MC visibility but not in the M3M-MC proximity or treatment decisions. The mean differences in MC visibility between paired scans ranged 0-0.22 with the upper bounds of the 95% confidence intervals (0.09-0.36) falling within the non-inferiority region.
The investigated low-dose CBCT protocols could provide acceptable image quality for the evaluation of impacted M3Ms in most cases. When compared to standard-dose CBCT, these low-dose CBCT images did not significantly affect the assessments of the M3M-MC proximity, treatment strategies, and patient management decisions made by GPs and OMFSs.
The low-dose protocols might be clinically acceptable for M3M management while greatly reducing radiation exposure.
本随机临床试验旨在评估低剂量锥形束 CT（CBCT）对下颌管（MC）可视性及其与下颌第三磨牙（M3M）之间的接近程度的影响，评估人员为普通牙科医生（GPs）和口腔颌面外科医生（OMFSs），并将其与标准剂量 CBCT 进行比较，评估其对临床决策的影响。
将 90 名患者的 154 颗埋伏 M3M 随机分为三组，分别进行两次 CBCT 照射，一次为标准剂量（333 mGy×cm），另一次为三种研究性低剂量（78-131 mGy×cm）方案之一。GP 和 OMFS 对图像进行了单独的 MC 可视性、M3M-MC 接近度、手术入路、冠/根部分和转诊决策的盲法评估。使用 Wilcoxon 符号秩检验对配对扫描中 MC 可视性进行两两比较，然后使用非劣效性检验，非劣效性边界为 0.5，采用四点量表。对配对扫描中其他变量的差异采用 Wilcoxon 符号秩检验或 McNemar 检验进行评估。
大多数观察者（78.5%-99.3%）在标准剂量 CBCT 上可清晰识别 MC。配对比较显示，仅在 MC 可视性方面，配对扫描之间存在显著差异，而在 M3M-MC 接近度或治疗决策方面则没有差异。配对扫描中 MC 可视性的平均差异范围为 0-0.22，95%置信区间（0.09-0.36）的上限落在非劣效性区域内。
在所研究的低剂量 CBCT 方案中，在大多数情况下，可提供可接受的图像质量来评估埋伏 M3M。与标准剂量 CBCT 相比，这些低剂量 CBCT 图像并未显著影响 GP 和 OMFSs 对 M3M-MC 接近度、治疗策略和患者管理决策的评估。
低剂量方案可能在 M3M 管理方面具有临床可接受性，同时大大降低了辐射暴露。
