Agreement between cone beam computed tomography images and panoramic radiographs for initial orthodontic evaluation.

OBJECTIVE: The aim of this study was to compare the agreement between cone beam computed tomography (CBCT) and panoramic radiographs for initial orthodontic evaluation. This study was not meant to test differences between imaging modalities or to indicate superiority of one technique. STUDY DESIGN: Thirty-eight subjects with both panoramic and CBCT images were retrospectively collected. Eight observers answered 14 observational questions. The observation was repeated after 4 weeks. RESULTS: CBCT images yielded better agreement between 2 observer groups (orthodontic residents and radiologists) and better inter- and intraobserver agreement. The agreement between panoramic radiographs and CBCT scans was moderate. CONCLUSIONS: If CBCT is a priori present in a case with justified indications, it has the potential to provide valuable diagnostic information for initial orthodontic evaluation and extra information for treatment planning. The moderate agreement between panoramic and CBCT images may indicate that the nature and amount of information gained from both imaging sources is deviant.

A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT) Part I. On subjective image quality.

AIMS: To compare image quality and visibility of anatomical structures in the mandible between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. MATERIALS AND METHODS: One dry mandible was scanned with five CBCT scanners (Accuitomo 3D, i-CAT, NewTom 3G, Galileos, Scanora 3D) and one MSCT system (Somatom Sensation 16) using 13 different scan protocols. Visibility of 11 anatomical structures and overall image noise were compared between CBCT and MSCT. Five independent observers reviewed the CBCT and the MSCT images in the three orthographic planes (axial, sagittal and coronal) and assessed image quality on a five-point scale. RESULTS: Significant differences were found in the visibility of the different anatomical structures and image noise level between MSCT and CBCT and among the five CBCT systems (p=0.0001). Delicate structures such as trabecular bone and periodontal ligament were significantly less visible and more variable among the systems in comparison with other anatomical structures (p=0.0001). Visibility of relatively large structures such as mandibular canal and mental foramen was satisfactory for all devices. The Accuitomo system was superior to MSCT and all other CBCT systems in depicting anatomical structures while MSCT was superior to all other CBCT systems in terms of reduced image noise. CONCLUSIONS: CBCT image quality is comparable or even superior to MSCT even though some variability exists among the different CBCT systems in depicting delicate structures. Considering the low radiation dose and high-resolution imaging, CBCT could be beneficial for dentomaxillofacial radiology.

In-vitro comparison of 2 cone-beam computed tomography systems and panoramic imaging for detecting simulated canine impaction-induced external root resorption in maxillary lateral incisors.

INTRODUCTION: The introduction of cone-beam computed tomography (CBCT) in dentomaxillofacial radiology has created new diagnostic challenges, including some potential opportunities for evaluating impacted teeth. The diagnostic accuracy for detection of simulated canine-induced external root resorption lesions in maxillary lateral incisors was compared between conventional 2-dimensional panoramic radiographic imaging and two 3-dimensional CBCT systems. METHODS: A child cadaver skull in the early mixed dentition was obtained from the Department of Anatomy, Hasselt University, Diepenbeek, Belgium, with ethical approval. This skull had an impacted maxillary left canine and allowed a reliable simulation. Simulated root resorption cavities were created in 8 extracted maxillary left lateral incisors by the sequential use of 0.16 mm diameter round burs in the distopalatal root surface. Cavities of varying depths were drilled in the middle or apical thirds of each tooth root according to 3 setups: slight (0.15, 0.20, and 0.30 mm), moderate (0.60 and 1.00 mm), and severe (1.50, 2.00, and 3.00 mm). The lateral incisors, including 2 intact teeth, were repositioned individually in the alveolus of the pediatric skull with approximal contacts to the impacted maxillary left canine. Three sets of radiographic images were obtained with panoramic Cranex Tome (Soredex, Helsinki, Finland), Accuitomo-XYZ Slice View Tomograph (J. Morita, Kyoto, Japan), and Scanora 3D CBCT (Soredex, Tuusula, Finland) for each tooth setup. Eight observers examined the 3 sets of 10 radiographs for resorption cavities. RESULTS: The differences in correct detection of simulated root resorption for all cavity sizes were significantly different (P <0.05) between the panoramic and both CBCT systems. CBCT imaging performance was significantly better than that of panoramic radiography for determining root resorption in the categories of slight and severe resorption. CONCLUSIONS: These results suggest that the CBCT radiographic method is more sensitive than conventional radiography to detect simulated external root resorption cavities.