Lappanakokiat Napas, Kim Soyeon, Larnani Sri, Park Young-Seok
PhD student, Department of Oral Anatomy and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
Full Professor and Dean, Department of Oral Anatomy and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
J Prosthet Dent. 2025 Jul 12. doi: 10.1016/j.prosdent.2025.06.026.
The impact of changing the patient's position on the trueness and precision of a desktop facial scanner using both stereophotogrammetry and structured light scanning technology has yet to be assessed.
The purpose of this in vitro study was to evaluate the trueness and precision of linear measurements obtained from 3-dimensional (3D) models generated by a desktop facial scanner, with a focus on the influence of patient positioning.
Two silicone-coated mannequin heads (1 male, 1 female) were scanned after being anteroposteriorly, mediolaterally, and superoinferiorly moved in front of a facial scanner at 1-cm intervals. Each mannequin underwent 3 scans per location, and 96 surface models per sex were analyzed. Fourteen anatomic landmarks were identified, and 16 linear measurements were recorded with digital calipers as reference values. Trueness was assessed by comparing the reference values with digital measurements, while precision was determined by the root mean square (RMS) derived from pairwise superimpositions of 3 models obtained from the same location. Intraobserver reliability was evaluated with intraclass correlation coefficients (ICCs) and technical error of measurement (TEM).
Most digital measurements deviated by less than 2 mm, with the largest deviation (2.5 mm) observed in the prn-pg line on the inferiorly placed male mannequin. Longer horizontal and anteroposterior distances showed reduced trueness, while superoinferior repositioning had the most impact. Precision analysis revealed minimal point-to-point deviations (mean RMS <0.20 mm across all directions). Intraobserver reliability was high (ICCs>0.990, TEM<0.05 mm).
The selected desktop facial scanner provides clinically acceptable accuracy across different scanning positions. However, longer measuring distances and positional changes in the superoinferior direction can affect accuracy. Special care is necessary when measuring the chin and nasal tip, particularly in individuals with prominent facial features.
使用立体摄影测量法和结构光扫描技术改变患者体位对台式面部扫描仪的准确性和精确性的影响尚未得到评估。
本体外研究的目的是评估从台式面部扫描仪生成的三维（3D）模型获得的线性测量的准确性和精确性，重点关注患者体位的影响。
两个硅胶涂层人体模型头部（1个男性，1个女性）在面部扫描仪前分别沿前后、内外侧和上下方向以1厘米的间隔移动后进行扫描。每个模型在每个位置进行3次扫描，共分析每种性别96个表面模型。确定了14个解剖标志点，并用数字卡尺记录了16条线性测量值作为参考值。通过将参考值与数字测量值进行比较来评估准确性，而精确性则由从同一位置获得的3个模型的成对叠加得出的均方根（RMS）确定。通过组内相关系数（ICC）和测量技术误差（TEM）评估观察者内可靠性。
大多数数字测量偏差小于2毫米，在低位放置的男性模型上，观察到最大偏差（2.5毫米）出现在鼻前棘-颏前点线上。较长的水平和前后距离显示准确性降低，而上下重新定位的影响最大。精确性分析显示点对点偏差最小（所有方向的平均RMS<0.20毫米）。观察者内可靠性较高（ICC>0.990，TEM<0.05毫米）。
所选的台式面部扫描仪在不同扫描位置提供了临床上可接受的准确性。然而，较长的测量距离和上下方向的位置变化会影响准确性。在测量下巴和鼻尖时需要特别小心，尤其是面部特征突出的个体。
