Aims: Assessment of the radiographs validity in the evaluation of the extent of the outer root apex resorption and comparison of the accuracy of measurement.
Materials and methods: The set included 17 patients in which the treatment with fixed appliance was indicated, together with the extraction of the maxillary first premolars. For six months, the unilateral force of 50 g was applied in the premolars, the force of 150 g was applied in counterlateral teeth. Then the teeth were extracted and measured. In all patients the intraoral RVG, OPG was taken as well as CT scans prior the treatment period and after that. CT scans were further used to make digital models. In all RTGs the length of a tooth, root, crown were measured prior and after the research.
Results: The accurracy of measurements done in radiographs was evaluated. The most precise results were obtained in measurements of teeth in CT scans. The difference between the real tooth dimensions and the values obtained from CT scans was statistically insignificant. Less accurate, however still reasonable results were obtained from intraoral RVGs, and rather inaccurate ones in 3D digital models. The least accurate results were found in OPGs measurements – the difference between the OPG result and the real dimensions was statistically significant.
Conclusion: The most accurate resorption measurements were found in CT scans and intraoral RVGs. Anyway digital models are very good for imagines of bone changes during intrusion at sinus maxillaris and panorex is excellent for discovery of severe EARR.