Thesis
The impact on diagnostic yield of the scan mode of cone beam CT images in artificial external root resorption
University of Iowa
Master of Science (MS), University of Iowa
Spring 2016
DOI: 10.17077/etd.4kcvr485
Abstract
<p>Introduction: Root resorption is an undesired but frequent side effect of orthodontic treatment. Several studies have already aimed to evaluate the performance of CBCT on this topic. However, none have addressed the peculiarities of the most common daily orthodontic scenario. The aim of the study was to evaluate the influence of CBCT scans on the diagnosis of artificial external root resorption in the apical third of anterior teeth.</p>
<p>Materials and methods: One hundred extracted human anterior teeth were randomly assigned to 2 uneven groups (51 as the control and 49 as the experimental group). A limited area of the apical third of the root of the teeth of the experimental group was selected and a buffer solution was used to induce tooth subsurface demineralization. Before CBCT image acquisition, each tooth was coated with an approximately 0.3 mm thick layer of utility wax to simulate the radiographic appearance of the periodontal space and placed into an empty mandibular anterior socket of a partially edentulous dry human mandible. The mandible was placed into a polystyrene box filled with water prior to the CBCT examination to simulate soft-tissue attenuation and scattering. The CBCT images were obtained on an i-CAT unit (i-CAT Next Generation, Imaging Sciences International, Hatfield, PA) according to three protocols: (I) half scan (180°), 0.40 mm voxel size; (II) full scan (360°), 0.40 mm voxel size; and (III) full scan (360°), 0.125 mm voxel size. The 300 resultant CBCT DICOM volumes were imported into InVivo software (InVivo5, Anatomage, San Jose, CA) for evaluation by three blinded, previously calibrated observers using a five-point confidence rating scale. Cohen’s kappa was used to calculate observers’ agreement. The diagnostic values of sensitivity (Sn), specificity (Sp) and accuracy (Ac) were performed by pooling observer responses for every image modality. Receiver operating characteristic (ROC) were built and the areas under the curve (AUC) were calculated. The Sn, Sp and Ac values were compared by Cochran’s Q test. The AUC values were compared by Mann-Whitney U test.</p>
<p>Results: The observers’ agreement ranged from 0.63 to 0.71, which was interpreted as a substantial agreement. Protocol III (0.125 mm voxel size) displayed the highest Sn (81.63 %), Ac (80.67%) and AUC (0.807). There were statistically significant differences between protocol III and the other two protocols (p < 0.001). The specificity of protocol I (84.97 %) was greater than that of protocols II (69.93 %) and III (79.74 %); however statistically significant difference was only found between protocols I and II (p = 0.005).</p>
<p>Conclusion: Although there was no difference in accuracy between the degrees of rotation (half and full scan) within the same voxel size (0.4 mm), there was a considerable difference between those and the smallest voxel size (0.125 mm). In fact, it may be suggested that a more dedicated, high resolution scan should be acquired when one intends to investigate the early stage of external root resorption during orthodontic treatment.</p>
Details
- Title: Subtitle
- The impact on diagnostic yield of the scan mode of cone beam CT images in artificial external root resorption
- Creators
- Saulo Leonardo Sousa Melo - University of Iowa
- Contributors
- Axel Ruprecht (Advisor)Veerasathpurush Allareddy (Committee Member)Veeratrishul Allareddy (Committee Member)
- Resource Type
- Thesis
- Degree Awarded
- Master of Science (MS), University of Iowa
- Degree in
- Oral Science
- Date degree season
- Spring 2016
- DOI
- 10.17077/etd.4kcvr485
- Publisher
- University of Iowa
- Number of pages
- x, 28 pages
- Copyright
- Copyright © 2016 Saulo Leonardo Sousa Melo
- Language
- English
- Description illustrations
- color illustrations
- Description bibliographic
- Includes bibliographical references (pages 25-28).
- Public Abstract (ETD)
Resorption of the roots of teeth is an undesired but frequent side effect of orthodontic treatment. The minor amount of resorption that is likely to occur early in treatment can be particularly difficult to record. Given that there is a predictability of root resorption after active treatment when the amount of resorption during early treatment stages is considered, it is important to have an accurate method to assess such condition. With respect to this matter, cone-beam computed tomography (CBCT) seems to be the most reliable imaging in dentistry. Several studies have already aimed to evaluate the performance of CBCT on this topic. However, none have addressed the peculiarities of the most common daily orthodontic scenario. The aim of this study was to evaluate the influence of the CBCT scan mode on the diagnosis of artificial external root resorption in anterior teeth. One hundred extracted human anterior teeth were randomly assigned to 2 groups. A limited area of the root of the teeth of the experimental group was selected and a chemical solution was used to induce tooth subsurface demineralization. Each tooth was placed into an empty socket of a partially edentulous dry human mandible. The CBCT images were obtained using three different protocols, varying the resolution of the scans. Three oral and maxillofacial radiology residents evaluated the images searching for any evidence of root resorption. The results suggest that a more dedicated, high resolution scan should be acquired when one intends to investigate the early stage of external root resorption during orthodontic treatment.
- Academic Unit
- Oral Pathology, Radiology and Medicine
- Record Identifier
- 9983777372602771
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