Abstract：
OBJECTIVE: The re-measurement of full-arch implant digital impressions is an important step in denture restoration. This paper provides an efficient oral photogrammetry technology using projective invariant marker, applied in the re-measurement of full-arch implant digital impressions.
METHODS: We have developed a self-recognizing marker with projection invariance, along with its detection code. The marker is installed on the scanning body and used for photogrammetric measurements. Triangulation is utilized to determine the 3D coordinates of the marker, followed by a series of post-processing steps to obtain more accurate 3D coordinates.
RESULTS: The experimental data indicate that the optimal working distance is between 200 and 250 mm, with a minimum measurement error of less than 0.05 mm and an average measurement error of 0.10 mm. The measurement time is less than 2 min.
CONCLUSIONS: The experimental results show that the photogrammetric system can obtain reliable positions of full-arch implants with efficient photogrammetry, without the need to enter the patient\'s oral cavity, and has potential clinical application value.
METHODS: We have developed a self-recognizing marker with projection invariance, along with its detection code. The marker is installed on the scanning body and used for photogrammetric measurements. Triangulation is utilized to determine the 3D coordinates of the marker, followed by a series of post-processing steps to obtain more accurate 3D coordinates.
RESULTS: The experimental data indicate that the optimal working distance is between 200 and 250 mm, with a minimum measurement error of less than 0.05 mm and an average measurement error of 0.10 mm. The measurement time is less than 2 min.
CONCLUSIONS: The experimental results show that the photogrammetric system can obtain reliable positions of full-arch implants with efficient photogrammetry, without the need to enter the patient\'s oral cavity, and has potential clinical application value.
摘要：
目的：重新测量全弓种植体数字化印模是义齿修复的重要步骤。本文提供了一种使用投影不变标记的有效的口腔摄影测量技术，应用于全弓植入物数字印模的重新测量。
方法：我们开发了一种具有投影不变性的自识别标记，以及它的检测代码。标记安装在扫描主体上并用于摄影测量。三角测量用于确定标记的3D坐标，随后进行一系列后处理步骤以获得更精确的3D坐标。
结果：实验数据表明，最佳工作距离在200至250mm之间，最小测量误差小于0.05mm，平均测量误差为0.10mm。测量时间小于2分钟。
结论：实验结果表明，摄影测量系统可以通过有效的摄影测量获得全弓植入物的可靠位置，不需要进入病人的口腔，具有潜在的临床应用价值。
方法：我们开发了一种具有投影不变性的自识别标记，以及它的检测代码。标记安装在扫描主体上并用于摄影测量。三角测量用于确定标记的3D坐标，随后进行一系列后处理步骤以获得更精确的3D坐标。
结果：实验数据表明，最佳工作距离在200至250mm之间，最小测量误差小于0.05mm，平均测量误差为0.10mm。测量时间小于2分钟。
结论：实验结果表明，摄影测量系统可以通过有效的摄影测量获得全弓植入物的可靠位置，不需要进入病人的口腔，具有潜在的临床应用价值。
