LAFAS, Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico, (Chief of the laboratory: Prof. Chiarella Sforza, MD), Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Milano, Italy.
LAFAS, Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico, (Chief of the laboratory: Prof. Chiarella Sforza, MD), Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Milano, Italy.
J Craniomaxillofac Surg. 2018 Sep;46(9):1493-1499. doi: 10.1016/j.jcms.2018.06.009. Epub 2018 Jun 13.
The present study compared the reliability of a low-cost laser scanner device to an already-validated stereophotogrammetric instrument. Fifty volunteers underwent duplicate facial scans through laser scanner and stereophotogrammetry. Intra- and inter-instrument reproducibility of linear distances, angles, facial surface area and volume was verified through the Bland-Altman test and calculation of absolute (TEM) and relative (rTEM) technical errors of measurement; rTEM was then classified as follows: <1% excellent; 1-3.9% very good; 4-6.9% good; 7-9.9% moderate; >10% poor. The scans performed through different devices were registered and superimposed to calculate the root mean square (RMS) (point-to-point) distance between the two surfaces. The same protocol was applied to a mannequin head. In inter-instruments comparison, 12/26 measurements showed a "good" rTEM; 5 were "very good". In intra-instrument comparison, most performances worsened, with only 10 of 26 measurements classified as "good" and "very good". All the measurements made on mannequin scans were at least "good", and 14/26 were "very good". Surface area was "very good" only in intra-instrument comparison; conversely, volumes were poorly repeatable for all the comparisons. On average, RMS point-to-point distances were 0.65 mm (inter-devices comparison), 0.56 mm (mannequin scans), 0.42 mm (intra-device comparison). In conclusion, the low-cost laser scan device can be reliably applied to inanimate objects, but does not meet the standards for three-dimensional facial acquisition on living persons.
本研究比较了一种低成本激光扫描仪设备与已验证的立体摄影测量仪器的可靠性。五十名志愿者通过激光扫描仪和立体摄影测量仪进行了两次面部扫描。通过 Bland-Altman 检验和测量的绝对（TEM）和相对（rTEM）技术误差的计算，验证了线性距离、角度、面部表面积和体积的仪器内和仪器间可重复性；然后将 rTEM 分为以下几类：<1%优秀；1-3.9%非常好；4-6.9%好；7-9.9%中等；>10%差。通过不同设备进行的扫描被注册和叠加，以计算两个表面之间的均方根（RMS）（点到点）距离。相同的协议适用于人头模型。在仪器间比较中，12/26 项测量的 rTEM 为“好”；5 项为“非常好”。在仪器内比较中，大多数性能恶化，只有 26 项测量中的 10 项被归类为“好”和“非常好”。对人头模型扫描的所有测量均至少为“好”，其中 14/26 项为“非常好”。表面积仅在仪器内比较中为“非常好”；相反，对于所有比较，体积的可重复性都很差。平均而言，RMS 点到点距离为 0.65 毫米（仪器间比较）、0.56 毫米（人头模型扫描）、0.42 毫米（仪器内比较）。总之，低成本激光扫描设备可可靠地应用于无生命物体，但不符合活体三维面部采集的标准。
