Larheim T A, Svanaes D B, Johannessen S
Oral Surg Oral Med Oral Pathol. 1984 Dec;58(6):736-41. doi: 10.1016/0030-4220(84)90045-8.
The precision of tooth-length assessments based on repeated panoramic radiographs made with a Siemens OP 5 was investigated in three groups of twenty patients. Two exposures of the same patient were made under three different radiographic conditions. Of the tooth lengths, nonmeasurability was found in 14% to 17%. The variability (standard deviation) of the measurements assessed from repeated radiographs ranged from 0.65 to 0.85 mm, or 2.4% to 3.1% of the mean radiographic tooth length in the different patient groups. The measurement error ranged from 0.43 to 0.56 mm, indicating that the main source of error inherent in the method was recognition of the reference points. Small differences were found between the tooth groups and between the right and left sides.
在三组每组20名患者中，研究了基于西门子OP 5拍摄的重复全景X线片进行牙齿长度评估的精度。在三种不同的X线摄影条件下对同一患者进行两次曝光。在牙齿长度方面，发现不可测量率为14%至17%。从重复X线片评估的测量值的变异性（标准差）在0.65至0.85毫米之间，占不同患者组平均X线片牙齿长度的2.4%至3.1%。测量误差在0.43至0.56毫米之间，表明该方法固有的主要误差来源是参考点的识别。在牙齿组之间以及左右两侧之间发现了微小差异。
