RPA Institute of Academic Surgery, Royal Prince Alfred Hospital, Sydney, NSW, Australia.
ARC Centre of Excellence for Electromaterial Science, Intelligent Polymer Research Institute, University of Wollongong, Wollongong, Australia.
Otol Neurotol. 2021 Feb 1;42(2):e177-e185. doi: 10.1097/MAO.0000000000002928.
Long term results of ossiculoplasty surgery are considered poor with displacement and extrusion amongst the common reasons for failure. Application of 3Dimensional (3D) printing may help overcome some of these barriers, however digital methods to attain accurate 3D morphological studies of ossicular anatomy are lacking, exacerbated by the limitation of resolution of clinical imaging.
20 human cadaveric temporal bones were assessed using micro computed tomography (CT) imaging to demonstrate the lowest resolution required for accurate 3D reconstruction. The bones were then scanned using conebeam CT (125 μm) and helical CT (0.6 mm). 3D reconstruction using clinical imaging techniques with microCT imaging (40 μm resolution) as a reference was assessed. The incus was chosen as the focus of study. Two different methods of 3D printing techniques were assessed.
A minimum resolution of 100 μm was needed for adequate 3D reconstruction of the ossicular chain. Conebeam CT gave the most accurate data on 3D analysis, producing the smallest mean variation in surface topography data relative to microCT (mean difference 0.037 mm, p < 0.001). Though the incus varied in shape in between people, paired matches were identical. Thus, the contralateral side can be used for 3D printing source data if the ipsilateral incus is missing. Laser based 3D printing was superior to extrusion based printing to achieve the resolution demands for 3D printed ossicles.
Resolution of modern imaging allows 3D reconstructions and 3D printing of human ossicles with good accuracy, though it is important to pay attention to thresholding during this process.
听骨链成形术的长期效果不佳，常见的失败原因包括移位和脱出。应用三维（3D）打印技术可能有助于克服其中一些障碍，但目前缺乏数字化方法来实现准确的听骨解剖学 3D 形态学研究，这加剧了临床影像学分辨率的限制。
对 20 个人体颞骨进行了微计算机断层扫描（CT）成像评估，以展示准确 3D 重建所需的最低分辨率。然后使用锥形束 CT（125μm）和螺旋 CT（0.6mm）对这些骨骼进行扫描。使用临床成像技术（以微 CT 成像（40μm 分辨率）为参考）评估 3D 重建。以砧骨为研究焦点。评估了两种不同的 3D 打印技术方法。
需要 100μm 的最小分辨率才能充分重建听骨链的 3D 结构。锥形束 CT 在 3D 分析中提供了最准确的数据，相对于微 CT，其表面形貌数据的平均差异最小（平均差异 0.037mm，p<0.001）。尽管砧骨在人与人之间形状不同，但配对匹配完全相同。因此，如果同侧砧骨缺失，可以使用对侧砧骨作为 3D 打印源数据。激光 3D 打印优于挤出式 3D 打印，可满足 3D 打印听小骨的分辨率要求。
现代成像的分辨率允许对人听小骨进行 3D 重建和 3D 打印，具有良好的准确性，但在这个过程中，注意阈值非常重要。
