Castroflorio Tommaso, Avolese Samuele, Sanna Fabrizio, Parrini Simone
Clear Aligner Academy, 10100 Torino, Italy.
Department of Mechanical and Aerospace Engineering, Polytechnic University of Turin, 10100 Torino, Italy.
Bioengineering (Basel). 2025 Aug 3;12(8):839. doi: 10.3390/bioengineering12080839.
To evaluate the concordance of automated 3D superimposition methods applied to digital models, with a focus on methods that consider stable palatal regions as geometric reference landmarks versus those that do not.
This was a prospective, cross-sectional study using digital model files of patients undergoing orthodontic treatment in a university clinical setting.
Sixty-one patients were prospectively enrolled and divided into three groups based on the type of orthodontic treatment they received: (20) non-extractive orthodontic treatment without intermaxillary elastics, (21) intermaxillary elastics, and (20) control subjects with no orthodontic movement. The inclusion criteria included the availability of complete pre- and post-treatment digital casts and the absence of significant craniofacial anomalies.
Three superimposition methods were tested: (1) superimposition according to palate and palatal ridges, (2) best-fit superimposition of arches in occlusion, and (3) best-fit superimposition of individual arches. Discrepancies were identified by comparing the spatial positions derived from each method. Within three spatial axes, deviations of ±0.5 mm and ±1.15° were not considered significant. Bland-Altman plots were used to quantify palatal rugae based and non-based spatial differences between methods. Differences in the superimposition results between the three patient groups were evaluated using ANOVA tests.
Differences in spatial position between the superimposition methods often exceeded the acceptable range. The results were compared between the three patient groups with a statistical significance of α = 0.05. In the present study, the high reliability of the superimposition method based on the palate and palatal ridges was observed.
Superimposition methods based on the palate and palatal rugae provide superior accuracy in determining treatment-related changes in upper arch digital models. These findings illustrate the need for appropriate selection of superimposition techniques based on the study objective of using clinically relevant techniques.
评估应用于数字模型的自动三维叠加方法的一致性，重点关注将稳定腭部区域视为几何参考标志的方法与不考虑该区域的方法。
这是一项前瞻性横断面研究，使用大学临床环境中接受正畸治疗患者的数字模型文件。
前瞻性纳入61名患者，根据他们接受的正畸治疗类型分为三组：（20名）接受非拔牙正畸治疗且未使用颌间弹力牵引的患者，（21名）使用颌间弹力牵引的患者，以及（20名）无正畸移动的对照受试者。纳入标准包括有完整的治疗前和治疗后数字模型，且无明显颅面异常。
测试了三种叠加方法：（1）根据腭部和腭嵴进行叠加，（2）咬合时牙弓的最佳拟合叠加，以及（3）单个牙弓的最佳拟合叠加。通过比较每种方法得出的空间位置来确定差异。在三个空间轴内，±0.5毫米和±1.15°的偏差不被视为显著。使用Bland-Altman图来量化基于腭皱襞和不基于腭皱襞的方法之间的空间差异。使用方差分析测试评估三组患者叠加结果的差异。
叠加方法之间的空间位置差异常常超过可接受范围。在α = 0.05的统计学显著性水平下比较了三组患者的结果。在本研究中，观察到基于腭部和腭嵴的叠加方法具有较高的可靠性。
基于腭部和腭皱襞的叠加方法在确定上颌牙弓数字模型中与治疗相关的变化方面具有更高的准确性。这些发现表明，需要根据使用临床相关技术的研究目标适当选择叠加技术。
