Quantitative analysis of apical root resorption by means of digital subtraction radiography.
OBJECTIVE
This study was performed to assess the diagnostic and quantifying ability of digital subtraction images for simulated apical root resorption, as well as to compare the diagnostic accuracy of conventional intraoral radiographs with digital subtraction images for this condition.


METHODS
Digital and intraoral radiographs of 10 sound maxillary central incisors and those with simulated apical root resorption were taken with varying horizontal and vertical angulations of the x-ray beam. Paired t tests were used to compare the lengths of the sound teeth on the images with their actual lengths, and the estimated amount of simulated apical root resorption was compared with the actual amount of tooth loss by means of Emago software. The diagnostic accuracy for detecting lesions was also evaluated on conventional intraoral radiographs and digital subtraction images through receiver operating characteristic (ROC) analysis.


RESULTS
There were no statistically significant differences between the actual lengths and those measured on the reconstructed images of the sound teeth. The calculated amounts of apical root resorption showed no statistically significant differences in comparison with the actual amounts (P >.05). The diagnostic accuracy of the conventional intraoral radiographs in detecting the lesions was low (ROC area = 0.6446).


CONCLUSIONS
A quantitative analysis of small amounts of apical root resorption can be performed by means of digital subtraction radiography.
Heo
M S
MS
Seoul National University, College of Dentistry, Korea.
Lee
S S
SS
Lee
K H
KH
Choi
H M
HM
Choi
S C
SC
Park
T W
TW
D006801:Humans; D007180:Incisor / Q000000981:diagnostic imaging; D012372:ROC Curve; D011857:Radiographic Image Interpretation, Computer-Assisted; D011861:Radiography, Dental / Q000379:methods; D019252:Radiography, Dental, Digital / Q000379:methods*; D015203:Reproducibility of Results; D012391:Root Resorption / Q000000981:diagnostic imaging*; D012986:Software Validation; D013382:Subtraction Technique; D019227:Tooth Apex / Q000000981:diagnostic imaging