Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Oral and Maxillofacial Surgery, Germany.
Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Radiology, Germany.
J Craniomaxillofac Surg. 2018 Sep;46(9):1533-1538. doi: 10.1016/j.jcms.2018.05.045. Epub 2018 May 31.
Despite the advantages and broad applications of alloplastic resorbable implants, postoperative radiological control is challenging due to its radiolucency. The aim of the present study was to evaluate the radiographic visibility of newly developed materials for orbital floor reconstruction.
The radiographic visibility of four different material combinations consisting of poly-(L-lactic acid)/poly-glycolic acid (PLLA/PGA) or poly(D,L-lactic acid) (PDLLA) enriched with magnesium (Mg), hydroxyapatite (HA) or β-tricalcium phosphate (β-TCP) with various layers of thicknesses (0.3, 0.6, and 1 mm), surgically placed above the orbital floor of a human head specimen, was evaluated using computed tomography (CT) and cone beam computed tomography (CBCT). The visibility was rated on a scale of 0-10 in CT/CBCT and by Hounsfield Units in CT for each subject.
All of the materials were clearly detectable in CT scans. Visibility was significantly higher (p < 0.001) in the standard soft tissue window (mean score: 7.3, ranging from 2 to 10) in comparison to the standard bone window (mean score: 5.2, ranging from 1 to 10). In CBCT (mean score: 3.3, ranging from 0 to 7), there was significantly lower but still sufficient visibility of the materials compared to the CT soft tissue window (p < 0.001) and CT bone window (p < 0.001). Comparing the different materials' visibility among the group of same layer thicknesses with each other, in the majority of cases, PDLLA enriched with β-TCP appeared to be most visible in both CT and CBCT.
The incorporation of radiopaque elements to PLLA/PGA and PDLLA polymers is a promising strategy to improve their visibility in CT and CBCT. Our data suggest that the reconstruction of the orbital floor with these new materials could provide an advantageous postoperative radiographic control.
尽管可吸收的异体植入物具有诸多优势且应用广泛，但由于其具有不透射线性，术后影像学控制仍具有挑战性。本研究旨在评估新型眶底重建材料的影像学可见性。
在人体头颅标本的眶底上方，分别放置由聚（L-乳酸）/聚（乙醇酸）（PLLA/PGA）或聚（D，L-乳酸）（PDLLA）与不同厚度（0.3、0.6 和 1mm）的镁（Mg）、羟基磷灰石（HA）或β-磷酸三钙（β-TCP）混合的四种不同材料组合，采用计算机断层扫描（CT）和锥形束 CT（CBCT）进行评估。对每个标本，通过 CT/CBCT 评分和 CT 的 Hounsfield 单位对其可视性进行评分，范围为 0-10。
所有材料在 CT 扫描中均清晰可见。在标准软组织窗（平均评分：7.3，范围 2-10）中，可视性明显高于标准骨窗（平均评分：5.2，范围 1-10）（p<0.001）。在 CBCT（平均评分：3.3，范围 0-7）中，与 CT 软组织窗（p<0.001）和 CT 骨窗（p<0.001）相比，材料仍具有足够的可视性，但可视性较低。在相同层厚的组内，比较不同材料的可视性，在大多数情况下，β-TCP 增强 PDLLA 在 CT 和 CBCT 中可视性最好。
将不透射线元素掺入 PLLA/PGA 和 PDLLA 聚合物中是提高其在 CT 和 CBCT 中可视性的一种有前途的策略。我们的数据表明，使用这些新材料进行眶底重建可以提供有利的术后影像学控制。
