Diagnostic Potential of Panoramic Radiography and CBCT in Detecting Implant-Related Ex Vivo Injuries of the Inferior Alveolar Canal Border.

The aim of this ex vivo study was to compare the diagnostic performances of panoramic radiography and cone beam computerized tomography (CBCT) in detecting implant-related injuries of the inferior alveolar canal. Monocortical bone windows were created in 60 fresh sheep hemimandibles, the inferior alveolar canals were revealed and 120 dental implants were inserted. Three types of injuries, described as pilot drill damage (PDRILL), collapsing of the superior border of the canal (COLL), penetration of the implant tip into the canal (PENET) and one control group, were simulated. Standard (PANO) and dentition mode panoramic (PANO-DENT) images as well as CBCT data presented as multiplanar reconstruction (MPR) and cross-sectional (CROSS) views were evaluated by 6 observers who had also expressed their level of confidence to their final diagnosis. Intra- and interobserver agreement scores were rated good. The area under the curve (AUC) values and the confidence scores for CROSS and multiplanar reformation (MPR) views were both significantly higher than those of PANO and PANO-DENT (P < .05 for each) in PDRILL group. In COLL group, observers showed less confidence to PANO and PANO-DENT compared to CROSS and MPR techniques (P < .05 for each). No other significant differences were found. Within the limits of this experimental study, it can be suggested that the standard and dentition modes of panoramic radiography can be as effective as CBCT in the detection of penetrating and collapsing injuries, but multiplanar and cross-sectional views of the CBCT are more accurate than panoramic radiography in the detection of pilot drill injuries in sheep mandible.

Direct Three-Dimensional Diagnosis of Ex Vivo Facial Fractures.

The aim of the present study is to assess the reliability and accuracy of different 3-dimensional (3D) reconstruction algorithms in detecting undisplaced condylar, zygomatic arc, and orbital rim fractures based on cone-beam computed tomography data set. Twenty sheep heads were used in the present study. Sixty fractured and 60 nonfractured (control) zones were randomly allocated. Three groups consisting of nondisplaced fractures of condyle (CF, n = 20), orbital (OF, n = 20), and zygomatic arc (ZF, n = 20) were created by using a diamond cutting disc. Soft tissues were only dissected and no fractures were generated in the control group (n = 60). The 3D reconstructions were created by using multiplanar reconstruction (MPR), surface rendering (SR), volume rendering (VR), and maximum intensity projection (MIP) algorithms. Final 3D models were examined in Osirix software (Pixmeo SARL, Bernex, Switzerland) by 6 observers. Diagnostic accuracies of each algorithm were statistically compared by receiver operating characteristics (ROC) and area under the ROC curves (AUCs). For the detection of CF, AUC for VR algorithm was found to be statistically larger than that of MIP while AUCs for VR and MIP were larger than those of MPR and SR for OF detection. For the detection of ZF, AUCs for MPR and VR were significantly larger than those of MIP and SR (P < 0.05 for each). Within the limitations of this experimental study, it can be concluded that for maxillofacial surgeons, it is more likely to detect condylar, orbital, and zygomatic fractures by using VR algorithm in 3D reconstruction.

A comparison of panoramic radiography and cone beam computed tomography in the detection of osteosynthesis complications in sheep mandibular angle fractures.

OBJECTIVE: The aim of this study was to compare the diagnostic efficacy of panoramic radiography (PANO) and cone beam computed tomography (CBCT) in detecting simulated complications of plate osteosynthesis applied to mandibular angle fractures (MAFs). STUDY DESIGN: Unfavorable MAFs were created in 100 fresh sheep hemimandibles. Fractures were fixed with 4-hole titanium miniplates and screws. Bone necrosis around the screws, penetration of the screw into the inferior alveolar canal, screw loosening, and plate breakage were simulated. The diagnostic efficacy of the imaging techniques was compared by using intra- and interobserver agreement scores and area under the receiver operating characteristic curve (AUC) values. Examination time (ET), confidence scores (CS), and planar preference (PP) in CBCT evaluation were assessed. RESULTS: Intra- and interobserver agreement scores varied between 0.61 and 0.91. AUCs for screw penetration into the inferior alveolar canal and screw loosening were significantly higher in CBCT than in PANO (P < .05). CBCT presented significantly higher ET and CS values compared with PANO (P < .05). PP showed significant differences among types of complications (P < .05). CONCLUSIONS: PANO provided acceptable outcomes in the detection of bone necrosis and broken plates around the screw, but CBCT was more likely to enable detection of all simulated types of complications with higher confidence.

Evaluation of perimandibular neurovascularization with accessory mental foramina using cone-beam computed tomography in children.

OBJECTIVES: The purpose of this study was to clarify the perimandibular neurovascularization with mandibular accessory mental foramina in a children population using cone-beam computed tomography (CBCT) to avoid complications during anesthetic and surgical procedures. METHODS: This retrospective study evaluated cone-beam CT images for bifid mandibular canals in the mandibles of 63 children (35 girls, 28 boys; age range, 7-16 years; mean age, 12.3 years). Both right and left sides were examined from CT images (n = 126), including axial, sagittal, cross-sectional, and panoramic views as well as reconstructed three-dimensional images, as necessary. The course, length, and superior and inferior angles between canals were classified and measured. RESULTS: Bifid mandibular canals were observed in 34 (27%) of the 126 sides examined. The most frequently encountered type of bifid canal was the retromolar canal (11.1%), followed by the forward (7.14%), buccolingual (6.35%), and dental canal (2.4%). Mean lengths of bifid canals were 10.2 mm on the right side and 10.6 mm on the left side. Mean superior angles were 131 degrees on the right side and 147 degrees on the left side, whereas mean inferior angles were 47 degrees on the right side and 34 degrees on the left side. No statistically significant differences were found in the lengths or angles between the right and left sides or between boys and girls (P < 0.05). The most common position for the mental foramen was between the first and second premolars, and an accessory mental foramen was observed in 4 children (6.34%). CONCLUSIONS: This study utilized CBCT images to identify bifid mandibular canals and accessory mental foramina in children. Cone-beam CT was found to be a useful technique for detecting secondary canals. However, despite the fact that CBCT uses less ionizing radiation than other types of three-dimensional imaging, unless the diagnostic information provided through CBCT improves treatment results, CBCT should not be recommended for use in children or adolescents.

Detection of crestal radiolucencies around dental implants: an in vitro experimental study.

PURPOSE: The aim of this study was to compare the diagnostic potentials and practical advantages of different imaging modalities in detecting bone defects around dental implants. MATERIALS AND METHODS: Crestal bone defects with sequentially larger diameters were randomly prepared around 100 implants that were inserted in bovine bone blocks. Conventional periapical radiography (PR), direct digital radiography (DDR), panoramic radiography (PANO), cone-beam computed tomography (CBCT), and multislice computed tomography (MSCT) were performed for all specimens. The diagnostic accuracies of the devices, confidence of the answers, subjective image quality, defect visibility in planar orientations, and duration of diagnosis were analyzed based on the interpretations of 7 calibrated observers. RESULTS: The agreement levels of intra- and interobserver scores were rated good. PR, DDR, and CBCT were mostly more accurate than PANO and MSCT (P < .05). Confidence levels were positively correlated with the defect size (ρ = 0.20, P < .01), and that of DDR was the highest (P < .05). The subjective image quality of PR and DDR was higher than that of CBCT, PANO, and MSCT (P < .05 for all comparisons). Axial-coronal-sagittal visibilities of the defects were higher for CBCT compared with MSCT (P < .05). The diagnostic time was shorter for DDR (P < .05) and longer for the tomographic systems (P < .05) than for the other devices. CONCLUSIONS: DDR may provide a faster and more confident diagnostic option that is as accurate as PR in detecting peri-implant radiolucencies. CBCT has a comparable potential to these intraoral systems but with slower decision making and lower image quality, whereas PANO and MSCT become more reliable when bone defects have a diameter that is at least 1.5 mm larger than that of the implant.

The influence of secondary reconstruction slice thickness on NewTom 3G cone beam computed tomography-based radiological interpretation of sheep mandibular condyle fractures.

OBJECTIVE: The objective of this study was to examine the diagnostic accuracy of the different secondary reconstruction slice thicknesses of cone beam computed tomography (CBCT) on artificially created mandibular condyle fractures. METHODS: A total of 63 sheep heads with or without condylar fractures were scanned with a NewTom 3G CBCT scanner. Multiplanar reformatted (MPR) views in 0.2-mm, 1-mm, 2-mm, and 3-mm secondary reconstruction slice thicknesses were evaluated by 7 observers. Inter- and intraobserver agreements were calculated with weighted kappa statistics. The receiver operating characteristic (ROC) curve analysis was used to statistically compare the area under the curve (AUC) of each slice thickness. RESULTS: The kappa coefficients varied from fair and to excellent. The AUCs of 0.2-mm and 1-mm slice thicknesses were found to be significantly higher than those of 2 mm and 3 mm for some type of fractures. CONCLUSION: CBCT was found to be accurate in detecting all variants of fractures at 0.2 mm and 1 mm. However, 2-mm and 3-mm slices were not suitable to detect fissure, complete, and comminuted types of mandibular condyle fractures.

Detection of vertical root fracture using cone-beam computerized tomography: an in vitro assessment.

OBJECTIVES: This study aimed to compare 2 cone-beam CT units [NewTom 3G (small FOV), Iluma (ultra/low resolution)] and an intraoral CCD sensor in the detection of vertical root fracture (VRF). STUDY DESIGN: The VRFs were created in 30 teeth, and 30 intact teeth served as control samples. All images were evaluated twice by 4 observers. Kappa coefficients were calculated to assess intra- and interobserver agreement, and t tests were used to compare Az values (alpha = 0.05). RESULTS: Both intra- and interobserver agreement values were higher for the ultra-resolution Iluma and NewTom 3G images compared with the low-resolution Iluma and intraoral CCD images. Az values for the ultra-resolution Iluma and NewTom 3G images were also higher than for the Iluma low-resolution and intraoral CCD images. No significant differences (P > .05) in diagnostic accuracy were found between the Iluma ultra-resolution and NewTom 3G images, with the exception of the second reading of observer 2 (P = .036), and no significant differences (P > .05) were found between the intraoral digital and low-resolution Iluma images. CONCLUSION: Both ultra-resolution Iluma and NewTom 3G images performed better than low-resolution Iluma and intraoral CCD images in the detection of VRF.