Data management practices of cone beam computed tomography volumes: An exploratory user survey.

OBJECTIVE: The aim of this study was to query cone beam computed tomography (CBCT) users about their storage and transfer practices to identify trends in the handling of CBCT data in dentistry. STUDY DESIGN: A computer-based survey was distributed to 2 CBCT user groups. The survey consisted of 18 questions on settings for data capture, data storage, archiving strategies, bit depth/compression, monitoring user access to patient information, and dissemination to end users. All information was anonymously collected. Descriptive data and frequency patterns were collected and discussed. RESULTS: A total of 68 surveys were returned, with 56 fully completed. Results reflected a low consensus about usage and management of radiographic data sets. Some preferential usage patterns, however, were noted along with the following trends: (1) 53% of respondents utilized Digital Imaging and Communications in Medicine volumetric data sets for initial storage. (2) 46% of respondents saved data in raw or native file formats. (3) 60% of storage sites were in onsite servers. (4) 35% of volumes saved were in a "Zip" compression format. (5) 37% of respondents used a picture archiving and communication system for storage. CONCLUSIONS: The absence of consensus on postcapture management of volumetric data sets indicates that a dentistry-wide data management standard would benefit patient care while mitigating information technology storage issues.

Effect of image sharpening on radiographic image quality.

STATEMENT OF PROBLEM: The image sharpening algorithm, unsharp masking (USM), may cause artifacts that reduce the diagnostic value of digital images. It may create overshoot artifacts that can be misdiagnosed as pathosis or prosthesis misfit. The effect of this image sharpening and the extent of overshoot artifacts on image quality requires investigation. PURPOSE: The purpose of this in vitro study was to evaluate the effect of USM on digital dental radiographic quality and to demonstrate the extent of overshoot artifacts. MATERIAL AND METHODS: Three digital sensors (2 complementary metal-oxide-semiconductors and 1 photostimulable phosphor) were exposed using a digital dental quality assurance imaging phantom to evaluate contrast resolution, spatial resolution, and dynamic range. The 3 sensors were again exposed without the phantom to determine the degree of radiographic noise. Each image was sharpened and then highly sharpened. Overshoot was measured, and images were compared using the Friedman 2-way ANOVA analysis. RESULTS: Image sharpening significantly affected spatial resolution and noise. Conversely, dynamic range and contrast resolution were not significantly affected by image sharpening. Overshoot artifacts increased with image sharpening. CONCLUSIONS: Image sharpening improves visual image quality but significantly increases overshoot artifacts that adversely affect radiographic diagnosis. Data from this study indicate that image sharpening causes artifacts that could negatively affect accurate diagnosis.

Prevalence and Size of Periapical Radiolucencies Using Cone-beam Computed Tomography in Teeth without Apparent Intraoral Radiographic Lesions: A New Periapical Index with a Clinical Recommendation.

INTRODUCTION: The purpose of this study was to determine the prevalence and size of periapical radiolucencies using cone-beam computed tomographic (CBCT) imaging in teeth without apparent signs of intraoral radiographic lesions. METHODS: One hundred twenty roots from 53 patients who had been determined to have no signs of intraoral radiographic lesions were included in this study. Limited-volume CBCT scans were taken at 0.125-mm3 voxel size. The widest area of apical radiolucency of each root canal-treated tooth was measured and assigned a numeric score based on the CBCT-Endodontic Radiolucency Index (ERI). CBCT data were evaluated by 2 radiologists with an interclass correlation coefficient of 0.96. RESULTS: The majority of roots (53.3%) had periodontal ligament widths ≤0.5 mm; 26.7% had radiolucency widths of 0.5 < x ≤ 1 mm, 15.0% had radiolucency widths of 1.0 < x ≤ 1.5 mm, 0.8% had radiolucency widths of 1.5 < x ≤ 2.0 mm, 1.7% had radiolucency widths of 2.0 < x ≤ 2.5 mm, and 2.5% had radiolucency widths of >2.5 mm. Patient age, recall interval, tooth type, and arch type had no statistically significant effect on the ERI distribution. CONCLUSIONS: Twenty percent of teeth with successful root canal treatment based on conventional periapical imaging had CBCT radiolucencies measuring greater than 1 mm. Because these radiolucencies may not be pathological changes, clinicians are cautioned against overtreatment of them before determining the true nature of these findings. Clinical studies with long follow-up times are needed to determine the proper course of actions for these cases.

The Influence of Adalimumab on the Healing of Apical Periodontitis in Ferrets.

INTRODUCTION: Given the increasing use of anti-tumor necrosis factor α (anti-TNFα) biologic medications, and their interferences with the immune-inflammatory response, this study evaluated the effect of adalimumab (anti-TNFα), on healing and healing time of apical periodontitis (AP) in ferrets. METHODS: Twelve male ferrets received cone beam computed tomography of the jaws at baseline health (T0); AP confirmation (T1); and 30 (T2), 60 (T3), and 90 (T4) days after root canal treatment (RCT) to monitor healing. All animals had AP induced in the canines; 3 ferrets (12 teeth) provided the positive controls for the histologic evaluation; 9 ferrets were randomly divided into 3 treatment groups with 12 teeth each in the following manner: Systemic: conventional RCT and systemic anti-TNFα; Local: RCT and periapical administration of anti-TNFα before canal obturation; conventional RCT only (control). Two calibrated radiologists assessed the cone beam computed tomography images independently and blindly for AP identification and quantification. Rank-based analysis of covariance was used for statistical analysis of lesion size. RESULTS: AP was induced in all teeth. Following RCT, all AP lesions in the 3 groups showed a significant reduction in size. Specific pairwise comparisons of the related samples (Friedman's 2-way analysis of variance by ranks within each group) demonstrated a decreasing trend in lesion size with healing time in all 3 groups, most pronounced for local group (local adalimumab). No statistical difference was noticed between groups. CONCLUSIONS: Both systemic and local anti-TNFα did not hinder AP healing in this animal model and a faster healing response may also be anticipated. These findings encourage follow-up studies with larger sample sizes.

Prevalence of Second Mesiobuccal Canals in Maxillary First Molars Detected Using Cone-beam Computed Tomography, Direct Occlusal Access, and Coronal Plane Grinding.

INTRODUCTION: The purpose of this study was to determine the prevalence of the second mesiobuccal canal (MB2) in 100 maxillary first molars using 3 independent methods and a combination method. METHODS: One hundred extracted human maxillary first molars were collected. The teeth were mounted in the maxillary first molar extraction sockets of a human cadaver head. A cone-beam computed tomographic (CBCT) scan was taken of each tooth. Two radiology faculty independently evaluated the CBCT volume for the presence of an MB2 canal. Additionally, teeth were accessed. If a canal was not found, a preoperative CBCT scan was viewed followed by a second attempt to locate an MB2 canal. Lastly, the mesiobuccal root was dissected by grinding in a coronal plane. RESULTS: A review of CBCT volumes found the presence of an MB2 canal 69% of the time. Accessing the tooth led to an MB2 detection of 78%. When a CBCT scan was viewed, this brought the access detection rate up to 87%. Coronal plane root grinding had an MB2 canal detection rate of 92%. Differences between each method were statistically significant. CONCLUSIONS: The results of this study show that an MB2 canal is present up to 92% of the time. Direct access of teeth found statistically significant more MB2 canals than viewing CBCT volumes alone (P = .032). Therefore, exposing every patient to a preoperative CBCT scan may not be appropriate. However, taking a CBCT scan when an MB2 canal is not found clinically can significantly increase the chances of finding an MB2 canal (P < .001).

Cone-beam computed tomography vs conventional radiography in visualization of maxillary impacted-canine localization: A systematic review of comparative studies.

INTRODUCTION: We systematically reviewed observational, experimental, and diagnostic accuracy studies to assess the comparisons between cone-beam computed tomography (CBCT) and conventional radiography (CR) in the localization of maxillary impacted canines. METHODS: An open-ended electronic search of PubMed, Web of Science, ProQuest, and other databases for both published and unpublished articles up to May 2016 was performed. The reference lists of the included studies were screened. Two authors performed the searches with no language restrictions. The research questions were outlined based on a hierarchical model. The primary outcomes were diagnostic accuracy, level of intermodalities agreement, effect of these images on treatment planning and treatment outcomes, and societal efficacy between the CBCT and CR in the localization of impacted canines. Two reviewers evaluated the risk of bias assessment by using the Quality Assessment of Diagnostic Accuracy Studies tool and the Newcastle Ottawa Scale. RESULTS: Eight studies met the inclusion criteria. Two studies reported diagnostic accuracy, 6 reported intermodalities agreement in impacted canine localization, and 3 reported treatment planning agreement between the modalities. No therapeutic and societal efficacy study found. The accuracy of CBCT ranged from 50% to 95%, and the accuracy of CR ranged from 39% to 85%. A wide range of kappa intermodalities agreement from 0.20 to 0.82, with observed agreement of 64% to 84%, was reported in canine localization. Broad kappa treatment planning agreement values from 0.36 to 0.72 were reported. Most studies suffered from a high risk of bias in subject selection. CONCLUSIONS: The fair to moderate intermodalities agreement in maxillary canine localization might mean that the information obtained through these modalities is deviant and ultimately might affect treatment planning. Although there is still a lack of strong evidence, CBCT is more effective than CR in evaluating cases that are difficult to diagnose in the initial evaluation with CR. FUNDING: No funding was received for this study.

Are three-dimensional airway evaluations obtained through computed and cone-beam computed tomography scans predictable from lateral cephalograms? A systematic review of evidence.

OBJECTIVE: To systematically review the literature correlating upper airway parameters between lateral cephalograms (LC) and cone-beam computed tomography (CBCT) or computed tomography (CT) scans to determine the utility of using LC to predict three-dimensional airway parameters. MATERIALS AND METHODS: Both electronic and manual searches of the included studies were performed by two reviewers, and the quality of the studies that met selection criteria were assessed. RESULTS: A total of 11 studies from the literature met the selection criteria. Assessed outcome variables showed correlation r < .7 between the LC and CT scans. The correlation between the LC and CBCT ranged from weak to strong with -.78 ≤ r and r ≤ .93 reported in the nasopharyngeal segment. In the oropharyngeal segment, a weak to strong correlation was reported with a range of -37 ≤ r and r ≤ .83 between the CBCT and LC. All associations in the hypopharyngeal segment showed a weak correlation. Four of studies were of weak quality, five were of moderate quality, and two were rated to be of strong quality. CONCLUSION: No strong correlations were reported between the LC and CT scans. However, the LC-derived adenoid-nasopharyngeal ratio and the linear measurement (posterior nasal spine, PNS, to posterior pharyngeal wall) had a strong correlation with upright nasopharyngeal area and volume in the CBCTs. The area measurement in conventional LC can be also used as an initial screening tool to predict the upright three-dimensional oropharyngeal volumetric data. The variability of the hypopharyngeal segment cannot be predicted by LCs. However, more well-designed studies are needed to determine the clinical utility of using LC to predict airway size.

Benign Fibro-Osseous Lesions of the Jaws.

Fibro-osseous lesions are grouped together because histologically they show similar cellular and mineralization patterns. Despite the histologic ubiquity, their behaviors vary significantly. Because of the histologic similarity and the broad range of morbidity among them, it is important to be able to differentiate between them in the preliminary diagnostic process. The radiographic presentations along with the location of the bony changes are often extremely critical diagnostic features to help render a differential or working diagnosis in lieu of an automatic biopsy procedure. Therefore the unique and specific radiographic presentations may be one of the main criteria for preliminary diagnosis.

Basic principles of cone beam computed tomography.

At the end of the millennium, cone-beam computed tomography (CBCT) heralded a new dental technology for the next century. Owing to the dramatic and positive impact of CBCT on implant dentistry and orthognathic/orthodontic patient care, additional applications for this technology soon evolved. New software programs were developed to improve the applicability of, and access to, CBCT for dental patients. Improved, rapid, and cost-effective computer technology, combined with the ability of software engineers to develop multiple dental imaging applications for CBCT with broad diagnostic capability, have played a large part in the rapid incorporation of CBCT technology into dentistry.

Measurement of skin dose from cone-beam computed tomography imaging.

OBJECTIVE: To measure surface skin dose from various cone-beam computed tomography (CBCT) scanners using point-dosimeters. MATERIALS & METHODS: A head anthropomorphic phantom was used with nanoDOT optically stimulated luminescence (OSL) dosimeters (Landauer Corp., Glenwood, IL) attached to various anatomic landmarks. The phantom was scanned using multiple exposure protocols for craniofacial evaluations in three different CBCT units and a conventional x-ray imaging system. The dosimeters were calibrated for each of the scan protocols on the different imaging systems. Peak skin dose and surface doses at the eye lens, thyroid, submandibular and parotid gland levels were measured. RESULTS: The measured skin doses ranged from 0.09 to 4.62 mGy depending on dosimeter positions and imaging systems. The average surface doses to the lens locations were ~4.0 mGy, well below the threshold for cataractogenesis (500 mGy). The results changed accordingly with x-ray tube output (mAs and kV) and also were sensitive to scan field of view (SFOV). As compared to the conventional panoramic and cephalometric imaging system, doses from all three CBCT systems were at least an order of magnitude higher. CONCLUSIONS: Peak skin dose and surface doses at the eye lens, thyroid, and salivary gland levels measured from the CBCT imaging systems were lower than the thresholds to induce deterministic effects. However, our findings do not justify the routine use of CBCT imaging in orthodontics considering the lifetime-attributable risk to the individual.

Comparison of technique errors of intraoral radiographs taken on film v photostimulable phosphor (PSP) plates.

OBJECTIVE: The objective of this study was to compare the technical errors of intraoral radiographs exposed on film v photostimulable phosphor (PSP) plates. METHODS: The intraoral radiographic images exposed on phantoms from preclinical practical exams of dental and dental hygiene students were used. Each exam consisted of 10 designated periapical and bitewing views. A total of 107 film sets and 122 PSP sets were evaluated for technique errors, including placement, elongation, foreshortening, overlapping, cone cut, receptor bending, density, mounting, dot in apical area, and others. Some errors were further subcategorized as minor, major, or remake depending on the severity. The percentages of radiographs with various errors were compared between film and PSP by the Fisher's Exact Test. RESULTS: Compared with film, there was significantly less PSP foreshortening, elongation, and bending errors, but significantly more placement and overlapping errors. Using a wrong sized receptor due to the similarity of the color of the package sleeves is a unique PSP error. CONCLUSIONS: Optimum image quality is attainable with PSP plates as well as film. When switching from film to a PSP digital environment, more emphasis is necessary for placing the PSP plates, especially those with excessive packet edge, and then correcting the corresponding angulation for the beam alignment. Better design for improving intraoral visibility and easy identification of different sized PSP will improve the clinician's technical performance with this receptor.

Evaluation of radiation exposure with Tru-Align intraoral rectangular collimation system using OSL dosimeters.

A pilot study to compare radiation exposure with the Tru-Align rectangular collimation system to round collimation exposures was undertaken. Radiation exposure at various points within the cross sections of the collimators and entrance, intraoral and exit dose measurements were measured using InLight OSL dosimeters. Overall dose reduction with the use of the rectangular collimation system was estimated by taking into account the ratios of collimator openings and the average radiation exposure at the measurement points. Use of the Tru-Align system resulted in an average radiation exposure within the perimeter of the projected outline of the rectangular collimator of 36.1 mR, compared to 148.5 mR with the round collimator. Our calculations indicate a dose reduction by a factor of approximately 3.2 in the case of the Tru-Align system compared to round collimation. The Tru-Align system was easy to use, but in some situations failed to allow Xray coverage of the entire surface of the image receptor, leading to cone cuts.

Comparison of the efficacy and technical accuracy of different rectangular collimators for intraoral radiography.

OBJECTIVE: The objective of this study was to compare the operating efficiency and technical accuracy of 3 different rectangular collimators. STUDY DESIGN: A full-mouth intraoral radiographic series excluding central incisor views were taken on training manikins by 2 groups of undergraduate dental and dental hygiene students. Three types of rectangular collimator were used: Type I ("free-hand"), Type II (mechanical interlocking), and Type III (magnetic collimator). Eighteen students exposed one side of the manikin with a Type I collimator and the other side with a Type II. Another 15 students exposed the manikin with Type I and Type III respectively. Type I is currently used for teaching and patient care at our institution and was considered as the control to which both Types II and III were compared. The time necessary to perform the procedure, subjective user friendliness, and the number of technique errors (placement, projection, and cone cut errors) were assessed. The Student t test or signed rank test was used to determine statistical difference (P

Infection control for dental radiographic procedures.

The employment of proper infection control procedures in the dental office is necessary to prevent the spread of infectious agents. The potential for cross contamination between dental personnel and the patient is considerable when exposing intraoral radiographs. The dental office darkroom or daylight loader can also be a potential contamination source if good infection control measures are not followed. By utilizing PPE, plastic barriers and disinfectants, DHCPs can minimize the likelihood of problems with contamination.

The accuracy and precision of third molar development as an indicator of chronological age in Hispanics.

The accuracy and precision of chronological age estimation based on the stages of third molar tooth development was studied in a sample of 679 radiographs from individuals of Hispanic origin. The age range was 14.0 to 25.0 years. Eight raters from the University of Texas Health Science Center at Houston Dental Branch evaluated the radiographs according to Demirjian's schematic definitions of crown and root formation. The objective of this study was to evaluate the chronology of third molar development in Hispanics following the protocol of a previous study. Within the Hispanic population, the rate of male third molar development is greater than that of female third molar development for ten stages of crown-root formation. Also within this Hispanic population sample, the rate of maxillary third molar development is ahead of mandibular third molar development. The mean absolute difference between chronological age and estimated age was +/-3.0 years in females and +/- 2.6 years in males.