Is the assessment of the mandibular molar danger zone affected by field of view and voxel size in cone beam computed tomography examinations?

OBJECTIVE: To verify if assessment of the danger zone (DZ) in the mesial root of mandibular molars is affected by field of view (FOV) and voxel sizes in cone beam computed tomography (CBCT) scans. STUDY DESIGN: Forty mandibular molars were scanned by micro-computed tomography, creating the reference standard. The teeth were then submitted for CBCT scans with FOVs of 10 × 5.5 cm and 5 × 5.5 cm and voxel sizes of 0.4, 0.2, 0.15, and 0.075 mm3. The smallest dentin thickness in the DZ from the mesiobuccal and mesiolingual canals was measured at 2, 4, and 6 mm apical to the root furcation. Descriptive statistics, paired t-tests, and intraclass correlation coefficients were used for statistical analysis with significance established at P < .05. RESULTS: All CBCT measurements overestimated the DZ dentin thickness (P < .001) compared to the reference standard. The greatest overestimation occurred in the 5 × 5.5 cm FOV with 0.4 mm3 voxels (P = .007). Dentin thickness measured with the 5 × 5.5 cm FOV and 0.075 mm3 voxels was significantly smaller and produced the best ICC value with the reference standard (0.936). CONCLUSIONS: CBCT overestimates the dentin thickness of the DZ regardless of FOV and voxel sizes. The 5 × 5.5 cm FOV showed the best performance with the 0.075 mm3 voxel size, but it performed poorly with 0.4 mm3 voxels.

Quantitative volume and area assessment of masticatory muscles through magnetic resonance imaging in patients with temporomandibular joint disorders.

OBJECTIVE: To compare volume and surface area measurements of the lateral pterygoid (LPM), medial pterygoid (MPM), and masseter muscles (MM) as calculated on magnetic resonance imaging (MRI) based on the position of the temporomandibular joint disk, mouth position, and patient sex, and to calculate the correlations of the measurements among the muscles. STUDY DESIGN: Measurements of muscle volume and area were performed on the MRIs of 51 patients. Wilcoxon, Kruskal-Wallis, and Mann-Whitney U tests were used to calculate the significance of differences in measurements. The Spearman correlation coefficient calculated the correlation of measurements among the muscles. The significance of difference was established at P < .05. RESULTS: Volume and area of the left MPM in patients with disk displacement without reduction (DDWOR) were larger than in patients with normal disk position (P ≤ .040). MM volumes were smaller with DDWOR than with DD with reduction bilaterally (P ≤ .031). The volume and area of LPM and MM were significantly different between closed and open mouth positions (P < .001). Differences in volume and area between females and males were significant for all muscles in volume (P ≤ .021) and for MPM and MM in area (P ≤ .021). Significant positive correlations were found among all muscles for volume and area. CONCLUSION: Volume and area measurements of the masticatory muscles varied according to disk and mouth position and patient sex and exhibited significant positive correlations.

Assessment of infection control in oral radiology during the COVID-19 outbreak: An international collaborative study.

Purpose: In the context of COVID-19, studies evaluating the adherence of dentists and dental students to infection control are relevant due to their high occupational exposure and risk, as well as their responsibility for disseminating information and good practices. This study evaluated the adherence of dentists and dental students to infection control in the oral radiology field in the setting of the COVID-19 pandemic on different continents. Materials and Methods: This cross-sectional observational study involved individuals who performed intraoral radiographic examinations during the COVID-19 pandemic. The Questionnaire on Infection Control in Oral Radiology was administered virtually using a Google Form. Participants from different continents (the Americas, Africa, Europe, Asia, and Oceania) were recruited. Data were subjected to descriptive analysis and simple and multiple binary regression (5%). Results: There were 582 valid answers, and 68.73% of the participants were from the Americas, 18.90% from Europe, and 12.37% from Asia. The median score for infection control protocols was 94 points for dental students and 104 points for dentists, and participants below the median were considered to have low adherence to infection control in oral radiology. Low access to infection control was found for 53.0% of dentists in the Americas, 34.0% from Europe, and 26.9% from Asia. Conclusion: The adherence to infection control protocols in oral radiology was low even in the face of the COVID-19 pandemic. The results may help improve the awareness of students and professionals, since oral radiology routines have the potential for transmitting COVID-19.

Assessment of the Metal Artifact Reduction Tool for the Detection of Root Isthmus in Mandibular Molars with Intraradicular Posts in Cone-beam Computed Tomographic Scans.

INTRODUCTION: This study evaluated the performance of the metal artifact reduction (MAR) tool in cone-beam computed tomographic scans using different fields of view (FOVs) in the detection of a root isthmus in mandibular molars with intraradicular posts. METHODS: Twenty-eight teeth were scanned by micro-computed tomographic imaging (gold standard images). Thereafter, specimens were allocated into the following groups: gutta-percha (teeth without posts, n = 10), a prefabricated metal post (n = 9), and a fiberglass post (n = 9). Cone-beam computed tomographic scans were taken using 8 acquisition protocols, varying the size of the FOV (10 × 5.5 cm and 5 × 5.5 cm) and the MAR tool (disabled, low, normal, and high modes). A root isthmus was evaluated considering a 5-point scale. Data were analyzed considering a 5% significance level. RESULTS: Intra- and interexaminer agreement varied from moderate to substantial. The frequency of correct diagnosis varied significantly in all groups regardless of the image acquisition protocol selected (P < .05). In the gutta-percha group, there was no difference in the accuracy, sensitivity, and specificity values between the tested protocols. In the metal and fiberglass post groups, the accuracy values were higher with the "disabled" and "low" modes of the MAR tool regardless of the FOV size. This was also observed for the sensitivity values in the metal post group (P < .05). CONCLUSIONS: The size of the FOV did not affect the performance of the MAR tool in the diagnosis of a root isthmus in molars with intraradicular posts. Our findings suggest that the use of the tool in the "normal" and "high" modes is contraindicated for this purpose.

In vitro assessment of periapical lesions created in sheep mandibles by using high resolution ultrasonography and cone beam computed tomography.

OBJECTIVES: Providing ultrasound images of periapical lesions may be problematic depending on the thickness of the overlying cortical bone. Clinically, it is crucial to determine the cut-off value of overlaying bone thickness in terms of interference with ultrasound imaging in conjunction with assessment of changes in periapical jaw bone lesions. Our aim was to determine the minimum amount of overlaying buccal bone thickness of artificial periapical lesions in order to be visible by ultrasound imaging and to compare width, height, depth, surface area and volume measurements of detectable periapical lesions obtained from ultrasound and CBCT images. METHODS: Periapical lesions were created in 16 molar teeth of sheep mandibles. Cavities were enlarged until the borders of lesions were visible on 14 MHz hockey probe ultrasound imaging. CBCT and ultrasound images were obtained simultaneously after drilling and enlarging each size of the cavities and replacing the teeth in their sockets. two observers separately assessed images twice within 2 weeks of interval. By using CBCT and ultrasound images, buccal bone thickness, maximum width, height, depth, surface area and volume of periapical lesions were measured. Intraclass correlation coefficient (ICC) was utilized and significance level was set at p < 0.05. RESULTS: The mean buccal bone thickness ranged between 1.21 mm and 1.31 mm for both imaging techniques. For the measurement of buccal bone thickness, periapical lesion width, height, depth, surface area, and volume excellent ICC values were found in terms of intrarater (ranging between 0.907 and 1) and inter-rater (ranging between 0.864 and 1) reliability for both observers and their readings. There were no statistically significant differences for both observers and for their two readings between ultrasound and CBCT measurements of buccal bone thickness, and periapical lesion width and height (p > 0.05). CONCLUSIONS: We suggested that a buccal thickness of approximately 1.28 mm might be accepted as a cut-off value for the detection of periapical lesions with 14 MHz hockey probe ultrasound. High resolution ultrasound provided accurate information for the measurement of buccal bone thickness and lesion width and height.

Assessment of intravertebral pneumatocysts, degenerative joint disease, and ponticulus posticus in the cervical spine through cone beam computed tomography examination.

OBJECTIVE: To identify the prevalence rates and radiologic characteristics of intravertebral pneumatocysts (IVP), degenerative joint disease (DJD), and ponticulus posticus (PP) in the cervical spine by using cone beam computed tomography (CBCT) images. The correlations of the lesions with patient age and sex, as well as the correlations among the lesions, were also evaluated. STUDY DESIGN: CBCT images obtained from 440 patients were assessed retrospectively. Correlations between patient demographic characteristics and IVP, DJD, and PP in the cervical vertebrae were analyzed by using χ2 tests and logistic regression analysis. A difference of P < .05 was considered statistically significant. RESULTS: IVP occurred in 22 of 1792 vertebrae (1.2%) and in 17 of 440 patients (3.9%). DJD findings were observed in the cervical vertebrae of 260 patients (59.1%). PPs were found in 245 patients (55.7%). The prevalence rate of DJD varied significantly by age group (P = .002), whereas the prevalence rates of IVP and PP did not. There was a significant correlation between both DJD and PP with demographic characteristics (P < .001) and between DJD and PP in patients without IVPs (P = .038). CONCLUSIONS: Although DJD is common, radiologists should carefully examine CBCT scans of vertebrae for IVP and PP. Patients with DJD should be evaluated for the presence of PP.

Versatility of high resolution ultrasonography in the assessment of granulomas and radicular cysts: a comparative in vivo study.

OBJECTIVES: To evaluate and compare the diagnostic potential of high resolution ultrasound with periapical radiographs (PR) and CBCT in assessing granulomas and radicular cysts. METHODS: This study included a total of 33 teeth from 33 patients with periapical lesions. Subjects were distributed among three groups. A consisted of teeth that were extracted. B consisted of teeth treated with root-canal treatment followed by apical surgery. C consisted of teeth treated with root-canal treatment only. Pre-treatment PR, ultrasound and CBCT images were obtained for Groups A, B and C and 6 month post-treatment PR and ultrasound images were obtained for Groups B and C. In addition, histopathological analysis was performed on lesions in Groups A and B. Lesions were classified as either cystic lesions or granulomas. Width, height, depth, surface area and volume of lesions were measured using the built-in softwares of the appropriate imaging modalities. Measurements were compared by Wilcoxon and paired sample t tests. Ultrasound and histopathological findings were compared with κ and Mc Nemar. Statistical significance was set at p < 0.05. RESULTS: κ coefficient (0.667; p = 0.002) suggested good agreement between ultrasound and histopathology. No statistically significant differences were found among periapical radiography, CBCT and ultrasound in the pre-treatment measurements of lesion width ( p = 0.308) or between CBCT and periapical radiography in the pre-treatment measurements of lesion height ( p = 0.863). In all cases, mean measurement values for all variables were lower for ultrasound than for CBCT. CONCLUSION: Ultrasound provided useful information for the diagnosis and assessment of granulomas and radicular cysts.

Qualitative and Quantitative Assessment of Alveolar Bone Destruction in Adult Rats Using CBCT.

Cone-beam computed tomography (CBCT) has strong potential to be utilized in various aspects of veterinary dentistry. Using ex vivo rat maxillary bone and teeth, the purpose of this study was to compare gray value, surface area, and volumetric measurements of teeth with and without experimental periodontitis by CBCT. Periodontitis was induced in 36 molar teeth, while 36 teeth with a healthy periodontium served as control. Images of each specimen along with teeth were obtained using CBCT. The following measurements for each tooth with periodontitis (n = 36) were recorded: gray value measurement, width, height, depth, surface area, and volume of the alveolar bone loss. For the control group (n = 36), gray value measurement, surface area, and volume of the alveolar bone were recorded. All measurements were repeated after 3 weeks. As the gold standard, the rat maxillas were decalcified and paraffin-embedded for further immunocytochemical study. One-way analysis of variance (ANOVA) was used. Significance level was set at P < .05. Correlation values for gray value, width, height, depth, surface area, and volume measurements were 0.983, 0.966, 0.962, 0.880, 0.998, and 0.999, respectively, for the first and second measurements. One way ANOVA showed statistically significant differences between teeth with and without alveolar bone destruction conducted for gray value, surface area, and volume measurements (P = .000). Mean gray value, surface area, and volume measurements decreased 56.46%, 81.89%, and 78.56%, respectively, for teeth with alveolar bone destruction in comparison to healthy teeth. Cone-beam computed tomography provided useful qualitative and quantitative information regarding induced periodontitis in the rat maxilla.

Change in Periapical Lesion and Adjacent Mucosal Thickening Dimensions One Year after Endodontic Treatment: Volumetric Cone-beam Computed Tomography Assessment.

INTRODUCTION: Changes in periapical lesion dimensions along with mucosal thickening after endodontic treatment have not been studied yet. Therefore, the objectives of this study were (1) to obtain linear and volumetric measurements of lesion dimensions in maxillary first molars with periapical pathology and (2) to measure maxillary sinus mucosal thickening in the vicinity of periapical lesions before and 1 year after endodontic treatment by using cone-beam computed tomography (CBCT). METHODS: Twenty-one maxillary first molar teeth of 21 patients (14 female and 7 male) with periapical lesion that had local mucosal thickening in the vicinity of the periapical lesion were endodontically treated. A total of 21 maxillary first molar roots (8 mesiobuccal roots, 6 distobuccal roots, and 7 palatal roots), each one from different patients, was included. Pretreatment and 1-year post-treatment CBCT images of each tooth were obtained by using Kodak CS 9300 3D CBCT unit. Width, height, surface area, and volume measurements of periapical lesions and mucosal thickening of the maxillary sinus mucosa in the vicinity of the periapical lesion were measured before and 1 year after endodontic treatment. General linear model (analysis of variance) was used for the comparisons between measurements, and significance was set at P < .05. Regression analysis was also used to test the correlation between different measurements. RESULTS: We found statistically significant differences between mean pretreatment and mean post-treatment measurements conducted by using CBCT images (width, P = .002; height, P < .001; maximum mucosal thickening, P < .001; medium mucosal thickening, P < .001; minimum mucosal thickening, P < .001; surface area, P = .032; and volume, P = .034). Considering gender, age, and root-type variables, no significant differences were found for all the measurements conducted (P > .05). There were 36%, 41%, 53%, 54%, 53%, 73%, and 75% mean reductions in lesion width, lesion height, maximum sinus mucosal thickness, medium sinus mucosal thickness, minimum sinus mucosal thickness, lesion surface area, and lesion volume, respectively, before and 1 year after endodontic treatment. Regression analysis of pretreatment lesion volume versus percentage of post-treatment lesion volume change revealed a low regression coefficient (R2 = 16.7%, P > .05), showing a weak linear relationship. CONCLUSIONS: CBCT assessment of changes in periapical lesion and mucosal thickening dimensions may reveal useful information regarding endodontic treatment success.

Assessment of zygomatic bone using cone beam computed tomography in a Turkish population.

OBJECTIVE: To provide linear and volumetric measurements of zygomatic bone using cone beam computed tomography (CBCT) images. STUDY DESIGN: CBCT images were assessed for 198 patients. Posterior and anterior zygomatic bone widths (M1 and M2), zygomatic bone projection (M3), zygomatic bone height (M4), combined zygomatic arch diameter (M5), maximum cortical thickness (M6), gray value obtained from maximum cortical thickness region (M7), minimum cortical thickness (M8), and gray value obtained from minimum cortical thickness region (M9) were measured. Volume and surface area measurements of the zygomatic bone were also conducted. Sex, age, and side were recorded for each patient. General linear model analysis of variance (ANOVA) was performed (P < .05). RESULTS: Age (P < .001) and gender (P = .001) significantly affected M1. Gender significantly affected M3 (P = .003) and M4 (P = .000), with higher values for men. Gender (P = .000) and age (P = .000) significantly affected M5 variation. Only age had a significant effect on M6 variation, with an increase with age (P < .015). Only gender had a significant effect on M7 (P = .005), M8 (P = .000), and M9 (P = .004), with higher values for men. All the factors significantly affected zygomatic bone volume variation (gender, P = .000; age, P = .000; and side, P < .004). CONCLUSION: Detailed examination of the zygomatic bone region can be performed with CBCT images.

Assessment of furcal perforations in the vicinity of different root canal sealers using a cone beam computed tomography system with and without the application of artifact reduction mode: an ex vivo investigation on extracted human teeth.

OBJECTIVE: To investigate observer ability to diagnose ex vivo simulated endodontic furcal perforations in root-filled teeth from cone beam computed tomography (CBCT) images using different artifact reduction algorithms. STUDY DESIGN: Our study consisted of 135 first maxillary molar teeth. In 89 teeth, furcation perforations were created using dental burs. Forty-six teeth without artificial perforations were used as controls. MTA Fillapex, Activ GP, and AH Plus were used with or without metal posts. All teeth were imaged using Planmeca ProMax 3-D Max CBCT, and four image modes were obtained as without artifact reduction and with artifact reduction in low, medium, and high modes. Images were evaluated by three observers for the presence or absence of furcation perforation using a five-point scale. Weighted kappa coefficients were calculated to assess observer agreement. Receiver operating characteristic analysis was performed. Areas under the curve (AUCs) were calculated for each image mode, observer, treatment group, and reading and were compared using Χ(2) tests, with a significance level of α = 0.05. The effects on diagnosis were calculated using analysis of variance (ANOVA). RESULTS: Intraobserver agreements for all observers ranged from 0.857 to 0.945. Kappa coefficients among different observers ranged from 0.673 to 0.763. AUC values ranged from 0.83 to 0.92, and there were no statistically significant differences (P > .05) between different CBCT image modes. Ratings in Activ GP treatment groups with or without posts showed statistically significant differences (P < .001). CONCLUSIONS: All CBCT image modes performed similarly in detecting furcal perforations near different root canal sealers with or without posts.

Effect of voxel size on accuracy of cone beam computed tomography-aided assessment of periodontal furcation involvement.

OBJECTIVE: To assess the accuracy of cone beam computed tomography (CBCT) images obtained at different voxel sizes in detecting ligature-induced furcation involvement. STUDY DESIGN: Furcation lesions were prepared in 36 molar teeth in rats, and 24 intact teeth served as controls. CBCT Kodak 9000 images at three different voxel sizes were acquired: 0.076 mm, 0.100 mm, and 0.200 mm. Four observers assessed 3 sets of images using a 5-point evaluation scale. κ-Coefficients were calculated for intra- and interobserver agreement. Receiver operating characteristic analysis measured the true positive rate (TPR), true negative rate (TNR), and area under the curve (AUC). Accuracy values were compared by using Mood's Median Chi-Square (α<0.05). RESULTS: Intra- and interobserver agreement ranged from 0.600 to 0.999 and from 0.366 to 0.573, respectively. Highest median AUC and true positive rate (TPR) values were obtained for voxel size of 0.076 mm. The highest median TNR values were obtained for the voxel size 0.1 mm. There were no significant differences (P≥.05) among the median AUC, TPR, or TNR values for the 3 different CBCT voxel sizes. CONCLUSIONS: Given the limitations of this study, all voxel sizes performed similarly in the detection of furcation involvement.

Accuracy of virtual models in the assessment of maxillary defects.

PURPOSE: This study aimed to assess the reliability of measurements performed on three-dimensional (3D) virtual models of maxillary defects obtained using cone-beam computed tomography (CBCT) and 3D optical scanning. MATERIALS AND METHODS: Mechanical cavities simulating maxillary defects were prepared on the hard palate of nine cadavers. Images were obtained using a CBCT unit at three different fields-of-views (FOVs) and voxel sizes: 1) 60×60 mm FOV, 0.125 mm(3) (FOV60); 2) 80×80 mm FOV, 0.160 mm(3) (FOV80); and 3) 100×100 mm FOV, 0.250 mm(3) (FOV100). Superimposition of the images was performed using software called VRMesh Design. Automated volume measurements were conducted, and differences between surfaces were demonstrated. Silicon impressions obtained from the defects were also scanned with a 3D optical scanner. Virtual models obtained using VRMesh Design were compared with impressions obtained by scanning silicon models. Gold standard volumes of the impression models were then compared with CBCT and 3D scanner measurements. Further, the general linear model was used, and the significance was set to p=0.05. RESULTS: A comparison of the results obtained by the observers and methods revealed the p values to be smaller than 0.05, suggesting that the measurement variations were caused by both methods and observers along with the different cadaver specimens used. Further, the 3D scanner measurements were closer to the gold standard measurements when compared to the CBCT measurements. CONCLUSION: In the assessment of artificially created maxillary defects, the 3D scanner measurements were more accurate than the CBCT measurements.

Nerve damage assessment following implant placement in human cadaver jaws: an ex vivo comparative study.

The present study compared the use of cone beam computerized tomography (CBCT) images and intra-oral radiographs in the placement of final implant drills in terms of nerve damage to cadaver mandibles. Twelve cadaver hemimandibles obtained from 6 cadavers were used. Right hemimandibles were imaged using peri-apical radiography and left hemimandibles using CBCT, and the images obtained were used in treatment planning for the placement of implant drills (22 for each modality, for a total of 44 final drills). Specimens were dissected, and the distances between the apex of the final implant drill and the inferior alveolar neurovascular bundle and incisive nerve were measured using a digital calliper. Nerves were assessed as damaged or not damaged, and the Chi-square test was used to compare nerve damage between modalities (P < 0.05). Nerve damage occurred with 7 final drills placed based on peri-apical radiography (31.8%) and 1 final drill placed using CBCT images (4.5%). The difference in nerve damage between imaging modalities was statistically significant (P = 0.023), with CBCT outperforming intraoral film in the placement of final implant drills ex vivo. In order to prevent nerve damage, CBCT is recommended as the principal imaging modality for pre-implant assessment.

Effect of clinician's experience, age, gender and calibration on the assessment of halitosis.

PURPOSE: To evaluate the diagnosis of halitosis in relation to the oral malodour judge's experience, age, gender and calibration. MATERIALS AND METHODS: This study included 38 dental patients who volunteered to participate. Patients were evaluated for halitosis by 6 clinicians using the organoleptic method and by measuring mouth exhaled air using a halimeter, which is considered the gold standard. Sensitivity, specificity, and positive and negative predictive values were calculated for each clinician. Consistency between clinicians was evaluated through a kappa test. Significance level was set at P < 0.05. RESULTS: Out of the 38 patients, 14 were diagnosed with halitosis by 6 clinicians using a halimeter. The highest sensitivity (89%) was found for clinician No. 6, followed by clinician No. 5 (78%). Specificities were 57% for clinician No. 4 and 36% for clinician No. 1 and No. 5. The most correct positive predictive value (halitosis according to halimeter readings) was made by clinician No. 6 (65%), who also had the highest rates (83%) of negative predictive value (no halitosis according to halimeter readings). There were no statistically significant differences (P > 0.05) between the diagnoses of clinicians No. 1, 2, 3, 5, or 6; however, the diagnoses made by clinician No. 4 were statistically different (P < 0.05) than those of all other clinicians. The highest rate of agreement (44%) in diagnoses was between the two calibrated clinicians. However, there was no correlation between the halitosis diagnoses and the age, gender and years of experience of the clinicians. CONCLUSIONS: This study indicates that calibration of clinicians is a significant factor in the organoleptic evaluation of halitosis.

Assessment of endodontically treated teeth by using different radiographic methods: an ex vivo comparison between CBCT and other radiographic techniques.

PURPOSE: To compare different radiographic methods for assessing endodontically treated teeth. MATERIALS AND METHODS: Root canal treatments were applied in 120 extracted mandibular teeth, which were divided into four groups: (1) ideal root canal treatment (60 teeth), (2) insufficient lateral condensation (20 teeth), (3) root canals filled short of the apex (20 teeth), (4) overfilled root canal treatment (20 teeth). The teeth were imaged using intraoral film, panoramic film, digital intraoral systems (CCD and PSP), CCD obtained with portable X-ray source, digital panoramic, and CBCT images obtained at 0.3 mm(3) and 0.2 mm(3) voxel size. Images were evaluated separately by three observers, twice. Kappa coefficients were calculated. The percentage of correct readings obtained from each modality was calculated and compared using a t-test (p<0.05). RESULTS: The intra-observer kappa for each observer ranged between 0.327 and 0.849. The inter-observer kappa for each observer for both readings ranged between 0.312 and 0.749. For the ideal root canal treatment group, CBCT with 0.2 mm(3) voxel images revealed the best results. For insufficient lateral condensation, the best readings were found with periapical film followed by CCD and PSP. The assessment of teeth with root canals filled short of the apex showed the highest percentage of correct readings by CBCT and CCD. For the overfilled canal treatment group, PSP images and conventional periapical film radiographs had the best scores. CONCLUSION: CBCT was found to be successful in the assessment of teeth with ideal root canal treatment and teeth with canals filled short of the apex.

Comparative assessment of subjective image quality of cross-sectional cone-beam computed tomography scans.

Since the introduction of cone-beam computed tomography (CBCT), several novel systems with different technical specifications and settings have become commercially available. Therefore, it is essential to evaluate CBCT systems for differences in the subjective quality of images obtained for various dental procedures. We evaluated the subjective image quality of cross-sectional scans obtained from various CBCT systems. Images of three cadaver mandibles were obtained from four different CBCT units: 1) Veraviewepocs 3D 40 × 40 mm field of view (FOV) (voxel size: 0.125 × 0.125 × 0.125 mm), 2) Iluma, low-resolution (voxel size: 0.3 × 0.3 × 0.3 mm), 3) Kodak, 50 × 3.7 cm FOV (voxel size: 0.076 × 0.076 × 0.076 mm), and 4) Vatech 12 × 8.5cm FOV (voxel size: 0.160 × 0.160 × 0.160 mm). We assessed subjective image quality and the visibility of 10 specific features, namely, caries, amalgam restoration, final implant drill, root canal filling, metal crown, mandibular canal, mental foramen, tooth (periodontal ligament space and lamina dura), trabecular pattern, and soft tissue. Images were viewed and scored by five calibrated observers, and image quality was ranked from best to worst. The Veraviewepocs 3D had the highest quality images for most of the assessed features, whereas the Iluma low-resolution scans were rated as the lowest quality images.

An Assessment of the Relationship between the Maxillary Sinus Floor and the Maxillary Posterior Teeth Root Tips Using Dental Cone-beam Computerized Tomography.

OBJECTIVES: The aim of the present study was to assess the relationship between the maxillary sinus floor and the maxillary posterior teeth root tips using dental cone-beam CT. METHODS: A total of 87 right and 89 left maxillary sinus regions from 92 patients were examined using dental cone-beam CT. Images were analyzed by a specialist in oral and maxillofacial radiology. Perpendicular lines were drawn on the cross-sectional images between the deepest point of the maxillary sinus floor and the root tips of the maxillary first and second premolars and first, second and third molars, and the distances were measured using built-in measurement tools. Means, standard deviations and minimum and maximum values were calculated for all right and left premolars and molars. T-tests were used to compare measurements between left and right sides and between female and male patients. RESULTS: The distance between sinus floor and root tip was longest for the first premolar root tip and shortest for the second molar buccodistal root tip for both right and left sides. No statistically significant differences were found between the right and left side measurements or between female and male patients (P>.05). CONCLUSIONS: Knowledge of the anatomical relationship between the maxillary sinus floor and the maxillary posterior teeth root tips is important for the preoperative treatment planning of maxillary posterior teeth.

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.