Root-contact evaluation by panoramic radiography and cone-beam computed tomography of super-high resolution

IntroductionCorrect tooth position in the 3 planes of space is a major objective of orthodontic treatment. The aim of this study was to determine whether a panoramic radiograph (OPT) provides a true assessment of the mesiodistal root relationship of adjacent teeth.MethodsOPTs of 22 patients near the end of treatment with fixed appliances in both arches were taken before debonding. When the roots of adjacent teeth were touching on the OPT, cone-beam computed tomography (CBCT) was used to show the true root relationships.ResultsWe evaluated 235 interdental sites by OPT and CBCT; 47 areas showed contact between adjacent roots in the OPT images. However, the CBCT images showed true contact in only 5 of these areas; ie, 11% of the diagnoses based on OPT images were true positive, whereas the rest (89%) was false positive. One hundred eighty-eight sites showed no contact in the OPT images; this was confirmed by CBCT.ConclusionsOPT has high sensitivity and relatively high specificity to detect adjacent roots touching each other. Root contacts are overestimated when evaluated by OPT.