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Objectives: To determine the efficacy of a deep-learning (DL) tool in assisting dentists in detecting apical radiolucencies on periapical radiographs. Methods: Sixty-eight intraoral periapical radiographs with CBCT-proven presence or absence of apical radiolucencies were selected to serve as the testing subset. Eight readers examined the subset, denoted the positions of apical radiolucencies, and used a 5-point confidence scale to score each radiolucency. The same subset was assessed by readers under two conditions: with and without Denti.AI DL tool predictions. For the two sessions, the performance of the readers was compared. The comparison was performed with the alternate free response receiver operating characteristic (AFROC) methodology. Results: Localization of lesion accuracy (AFROC-AUC), specificity and sensitivity (by lesion) detection demonstrated improvements in the DL aided session in comparison with the unaided reading session. Subgroup performance analysis revealed an increase in sensitivity for small radiolucencies and in radiolucencies located apical to endodontically treated teeth.. Conclusion: The study revealed that the DL technology (Denti.AI) enhances dental professionals' abilities to detect apical radiolucencies on intraoral radiographs. Advances in knowledge: DL tools have the potential to improve diagnostic efficacy of dentists in identifying apical radiolucencies on periapical radiographs.

Background The development of specialized panoramic radiograph machine software has spawned the introduction of an innovative and promising dental radiographic examination type: extraoral bite-wings. But does this unconventional type of imaging belong in the bite-wing family? Is there any relationship at all to the conventional bite-wing radiograph? Objectives The purpose of this article is not to make a case for the diagnostic effectiveness of one system over the other; this is best left to further clinical evaluation. Instead, the authors intend to provide an outline of a few key and distinguishing elements of the intraoral bite-wing radiographic examination followed by those of the extraoral panoramic substitute and draw attention to the importance of reimagining the increasingly universal naming convention of this novel radiographic examination, the paradoxical “extraoral bite-wing radiograph”, based on the fundamental principles of each of these imaging systems. Practical Implications The accuracy of clinical and technical terminology in oral radiography is of paramount importance to both the profession and patients, especially when considering emerging technologies.

Cone beam computed tomography (CBCT) is now widely used in dentistry and growing areas of medical imaging. The presence of strong metal artifacts is however a major concern of using CBCT especially in dentistry due to the presence of highly attenuating dental restorations, fixed appliances, and implants. Virtual monoenergetic images (VMIs) synthesized from dual energy CT (DECT) datasets are known to reduce metal artifacts. Although several techniques exist for DECT imaging, they in general come with significantly increased equipment cost and not available in dental clinics. The objectives of this study were to investigate the feasibility of developing a low-cost dual energy CBCT (DE-CBCT) by retrofitting a regular CBCT scanner with a carbon nanotube (CNT) x-ray source with dual focal spots and corresponding low-energy (LE) and high-energy (HE) spectral filters. A testbed with a CNT field emission x-ray source (NuRay Technology, Chang Zhou, China), a flat panel detector (Teledyne, Waterloo, Canada), and a rotating object stage was used for this feasibility study. Two distinct polychromatic x-ray spectra with the mean photon energies of 66.7keV and 86.3keV were produced at a fixed 120kVp x-ray tube voltage by using Al+Au and Al+Sn foils as the respective LE and HE filters attached to the exist window of the x-ray source. The HE filter attenuated the x-ray photons more than the LE filter. The calculated post-object air kerma rate of the HE beam was 31.7% of the LE beam. An anthropomorphic head phantom (RANDO, Nuclear Associates, Hicksville, NY) with metal beads was imaged using the testbed and the images were reconstructed using an iterative volumetric CT reconstruction algorithm. The VMIs were synthesized using an image-domain basis materials decomposition method with energy ranging from 30 to 150keV. The results were compared to the reconstructed images from a single energy clinical dental CBCT scanner (CS9300, Carestream Dental, Atlanta, GA). A significant reduction of the metal artifacts was observed in the VMI images synthesized at high energies compared to those from the same object imaged by the clinical dental CBCT scanner. The ability of the CNT x-ray source to generate the output needed to compensate the reduction of photon flux due to attenuation from the spectral filters and to maintain the CT imaging time was evaluated. The results demonstrated the feasibility of DE-CBCT imaging using the proposed approach. Metal artifact reduction was achieved in VMIs synthesized. The x-ray output needed for the proposed DE-CBCT can be generated by a fixed-anode CNT x-ray source.

Objective: To investigate the differences in imaging characteristics and the diagnostic accuracy of 225 intraosseous jaw lesions on panoramic radiographs (PAN) versus cone beam computed tomography (CBCT). Methods: 225 sets of PAN and CBCT images with biopsy-proven histopathological diagnoses were retrospectively compared in terms of radiographic features and diagnostic accuracy. The imaging characteristics of PAN and CBCT were independently evaluated by two oral and maxillofacial radiologists who were required to answer 12 questions and provided up to three differential diagnoses with their confidence scores. Results: Odds ratios (ORs) were statistically significant for border cortication (OR = 1.521; p = .003) and border continuity (OR = 0.421; p = .001), involvement on neurovascular canals (OR = 2.424; p < .001), expansion (OR = 7.948; p < .001), cortical thinning (OR = 20.480; p < .001) as well as its destruction (OR = 25.022; p < .001) and root resorption (OR = 2.477; p < .001). Furthermore, imaging features in the posterior and mandibular regions showed better agreement than those in the anterior and maxillary regions, respectively. The diagnostic accuracy of the first differential diagnosis was higher on CBCT than on PAN (Observer 1:78.7 vs 64.4%; Observer 2: 78.7 vs 70.2% (p < .001)). The observers’ confidence scores were also higher at CBCT interpretation compared with PAN. Conclusions: CBCT demonstrated a greater number of imaging characteristics of intraosseous jaw lesions compared with PAN, especially in the anterior regions of both jaws and in the maxilla. Diagnostic accuracy is improved with CBCT compared to PAN, especially for lesions in the maxilla. Radiologists have greater confidence when using CBCT.

Objective: To evaluate the occurrence of cervical vertebrae anomalies (CVA) in patients with unilateral (UCLP) and bilateral cleft lip and palate (BCLP) using cone beam computed tomography (CBCT) examinations. Design: Retrospective assessment of CBCT images. Descriptive statistics were calculated. Fisher exact test or χ2 test was performed to evaluate the differences among each CVA between sex and type of cleft. Setting: School of Dentistry. Participants: One hundred fifty-one patients with cleft lip and palate (103 UCLP/48 BCLP). Interventions: No relevant intervention. Main Outcome Measures: Cone beam computed tomography images were assessed for the presence or absence of 12 most commonly observed CVA: spina bifida, dehiscence, cleft of the posterior arch, cleft of the anterior arch, fusion between cervical vertebrae, block fusion, occipitalization, narrowing of the intervertebral space, posterior ponticle, os odontoideum, ossiculum terminale, and subdental cartilaginous remnants. Results: The presence of subdental cartilaginous remnants was the most frequently observed alteration—found in 81.45% of the sample—and it was the only CVA with statistically significant frequencies in the individuals with BCLP. Considering only the other CVA, 22.51% presented 1 and 5.29% presented 2 or more CVA. Conclusions: Patients with cleft lip and palate may present an overall high incidence of CVAs. However, when comparing the distribution of the CVAs among sex and types of cleft, the only significant difference noted was a higher incidence of subdental cartilaginous remnants among patients with BCLP.

To evaluate the utility of an individualized template for corrective surgeries for patients suffering from mandibular asymmetry. Twenty patients with history of favorable clinical outcome of the correction of their mandibular asymmetry were chosen. CBCTs were taken before and 6 weeks postoperative using NewTom 3G. Each volume is mirrored and registered on the cranial base. Surface models for the mandible and its registered mirror were used to compute a template using deformable fluid registration. Surgery was simulated based of the resulting template. A multi-center survey using “Qualtrics” was conducted to gain clinical feedback of 20 surgeons/orthodontists comparing treatment outcomes. Twenty-three clinicians participated. More clinicians rated simulated outcome to be “Good,” whereas the actual surgical outcomes were rated as “fair” and “poor.” This was true for regional appraisal for the chin, Rami, and body of the mandible as well as the overall assessment of the outcome of surgeries. The gains of computer-assisted simulation tend to be greater for difficult cases especially for the body of the mandible, then the chin, and then the Ramus correction. This approach has the potential to optimize and increase the predictability of the outcome of craniofacial corrective surgeries for asymmetric patients.

BACKGROUND It has been well documented that the frequency of incidental findings in cone beam computed tomography (CBCT) scans is relatively high. These incidental findings range from low to high significance. Research has shown that many of these findings are not detected on 2D computed tomography or CBCT. CBCT scans vary from small to large field of view (FOV). One strategy to reduce the number of incidental findings and liability is to decrease the FOV. OBJECTIVE(S) The aim of this study was to record what significant incidental findings can be seen on 2D intraoral imaging that were reported on CBCT imaging. A second aim was to compare the frequency of significant incidental findings in multiple CBCT fields of view. STUDY DESIGN CBCT reports at the University of North Carolina between 2017 and 2019 were reviewed. Reports included scans taken on the Orthophos SL 3D and 1 of 3 FOVs (5 × 5 × 6, 8 × 8 × 8, 11 × 11 × 10). A total of 170 reports for each of the 3 FOVs were used, for a total of 510 reports. For each report all significant incidental findings were recorded. Two-dimensional intraoral and panoramic images taken within 1 year of the CBCT were reviewed by 2 oral and maxillofacial radiologists to determine visibility on 2D imaging. RESULTS A total of 673 significant incidental findings were reported. The frequency of significant incidental findings changed significantly between 5 × 5 × 6 (101) and 8 × 8 × 8 (275) but did not change significantly between 8 × 8 × 8 (275) and 11 × 11 × 10 (297). The different types of incidental findings increased with all 3 FOVs. Detection frequency of incidental findings in CBCT that were also found in 2D radiographs were 5 × 5 × 6 (34%), 8 × 8 × 8 (36%), and 11 × 11 × 10 (40%). DISCUSSION/CONCLUSIONS The frequency of type of incidental findings increases with increasing FOV from 5 × 5 × 6 to 8 × 8 × 8 or 11 × 11 × 10. A large portion of incidental findings detected on CBCT are not detected on 2D imaging.

BACKGROUND Dentists rely on radiographs in making treatment decisions every day. However, if inattentively read, radiographs can lead to over- or undertreatment. OBJECTIVE(S) The objectives were to assess the diagnostic performance of a deep learning algorithm at detecting apical radiolucencies (ARs) on intraoral (IO) radiographs and compare the performance of the algorithm vs interpretation by experts. STUDY DESIGN A search was conducted using the University of North Carolina cone beam computed tomography (CBCT) referral database for volumes acquired for endodontic evaluation. The inclusion criteria consisted of permanent teeth that exhibited apical radiolucencies measuring ≥2 mm on CBCT with a diagnostic IO radiograph for the same site. The exclusion criteria included patients under 18 years old and CBCT and IO images acquired more than 6 months apart. After applying the inclusion and exclusion criteria, 192 cases were found. The CBCT volumes served as ground truth for the IO radiograph annotation. The IO radiographs were randomly assigned to one of 3 groups: 6 images, observer calibration; 54 images, training the artificial intelligence (AI) algorithm; 132 images, testing set. Additionally, 132 IO radiographs with no evidence of apical radiolucencies were included to serve as controls. For this pilot, 70 images were randomly selected to create a testing subset derived from the main control and positive testing sets. Three experts were presented with this testing subset and asked to independently determine locations of AR and confidence of presence using a 5-point Likert scale. RESULTS The standalone software performance results by tooth were as follows: Sensitivity was 93%, specificity was 88%, and the area under the receiver operating characteristic curve (ROC-AUC) was 94% (95% confidence interval [CI], 89%, 98%). The combined results of the experts were as follows: sensitivity was 87%, specificity was 97%, and ROC-AUC was 93% (95% CI, 88%, 98%). Notably, the software performance metrics were lowest in the maxillary posterior region. DISCUSSION/CONCLUSIONS Using a limited testing data set, AI provided comparable performance to expert observers for this task. Further AI training is necessary to increase the sensitivity and specificity of AR detection in the posterior maxillary region.

The aim of this study was to (1) compare bone loss detection accuracy with intraoral radiography and registered cone beam computed tomography (CBCT); (2) assess repeatability with both modalities; (3) determine factors affecting defect detection; and (4) determine the effect of buccolingual bone thickness on defect detection.Six observers viewed intraoral radiographs and CBCT scans before and after the defect to determine defect presence and extent. Receiver operating characteristic (ROC), sensitivity, specificity, logistic regression, odds ratio, intraclass correlation coefficient, and weighted kappa were used.CBCT and intraoral radiography mean ROC area under the curve values were not statistically different (0.90 vs 0.81; P = .06). CBCT had higher sensitivity compared with intraoral radiography (0.85 vs 0.63; P = .01) but similar specificity (0.91 vs 0.84; P = .45). Bone thickness, imaging modality, and observer had significant effects on defect detection (P.001). Odds ratios for CBCT vs intraoral radiography were 2.29 for diagnostic accuracy and 1.52 for buccolingual bone thickness. There was moderate interobserver agreement for detection of defects and substantial intraobserver agreement for measurement of extent.CBCT showed equivalent diagnostic efficacy and specificity for defect detection and higher sensitivity compared with intraoral radiography. CBCT increases the odds of accurate defect assessment more than 2-fold compared with intraoral radiography. The odds of bone loss detection increase by approximately 50% per millimeter of buccolingual alveolar bone loss.

This study explored the necessity of perioperative antibiotics on survival rates of implants immediately placed and provisionalized into sites with infection. Subjects were randomly assigned into antibiotic or placebo groups. Extraction, immediate placement, and provisionalization of an implant were performed. Eight subjects received placebo and five subjects received both a pre- and post-operative antibiotic regimen. One implant from each group failed. Perioperative antibiotic therapy may not be needed in selected immediate implant therapy.

Objectives/Hypothesis The aim of this study was to compare the volume of nasopharyngeal airways of patients with unilateral cleft lip and palate (UCLP) with a control (noncleft) group of subjects. Study Design Retrospective case-control study. Methods The sample consisted of 45 subjects, 30 with UCLP who underwent cone beam computed tomography (CBCT) exams as part of their workups for alveolar bone graft and 15 noncleft subjects seeking orthodontic care who obtained CBCT for diagnostic purposes. The three-dimensional volumes of nasal (NV) and oropharyngeal (PV) airways of these subjects were assessed separately using Mimics software by one well-calibrated evaluator. The images were rendered, and the volumes were measured in cm3. Results The mean PV of the UCLP subjects was 6.7 cm3 and the mean NV was 10.3 cm3. The control group presented with a mean PV of 8.1 cm3 and a mean NV of 11.6 cm3. Student t test showed no statistically significant difference for PV (P = 0.10) or NV (P = 0.23) when comparing cleft and noncleft subjects. Conclusion Evaluation of the nasopharyngeal airways revealed that the NV and PV airways showed no difference between the cleft and noncleft subjects. It is interesting to postulate that the reported nasal abnormalities of the cleft patients do not produce a significant measurable effect on the overall volume, at least as shown in our study sample. In addition, the nasopharyngeal airways of patients are not larger than those of age-matched controls, at least at the ages that were sampled, after cleft palate repair. Level of Evidence 3b. Laryngoscope, 125:736–739, 2015

Proximal dental caries remains a prevalent disease with only modest detection rates by current diagnostic systems. Many new systems are available without controlled validation of diagnostic efficacy. The objective of this study was to evaluate the diagnostic efficacy of three potentially promising new imaging systems.This study evaluated the caries detection efficacy of Schick 33 (Sirona Dental, Salzburg, Austria) intraoral digital detector images employing an advanced sharpening filter, Planmeca ProMax(®) (Planmeca Inc., Helsinki, Finland) extraoral "panoramic bitewing" images and Sirona Orthophos XG3D (Sirona Dental) CBCT images with advanced artefact reduction. Conventional photostimulable phosphor images served as the control modality. An ex vivo study design using extracted human teeth, ten expert observers and micro-CT ground truth was employed.Receiver operating characteristic analysis indicated similar diagnostic efficacy of all systems (ANOVA p 0.05). The sensitivity of the Schick 33 images (0.48) was significantly lower than the other modalities (0.53-0.62). The specificity of the Planmeca images (0.86) was significantly lower than Schick 33 (0.96) and XG3D (0.97). The XG3D showed significantly better cavitation detection sensitivity (0.62) than the other modalities (0.48-0.57).The Schick 33 images demonstrated reduced caries sensitivity, whereas the Planmeca panoramic bitewing images demonstrated reduced specificity. XG3D with artefact reduction demonstrated elevated sensitivity and specificity for caries detection, improved depth accuracy and substantially improved cavitation detection. Care must be taken to recognize potential false-positive caries lesions with Planmeca panoramic bitewing images. Use of CBCT for caries detection must be carefully balanced with the presence of metal artefacts, time commitment, financial cost and radiation dose.

This study aimed to evaluate the accuracy of three different methods for assessing the volume of cleft defects in CBCT images. The influence of field of view (FOV) and voxel sizes was also assessed.Using three radio-opaque plastic skulls, unilateral defects were created to mimic alveolar clefts and were filled with wax following the contralateral side contours. They were scanned in a CBCT unit using four different acquisition protocols, varying FOV and voxel sizes. Using three different methods, the defect/wax volume was evaluated on the images by defining: (1) the width, height and facial-palatal length of the defect in maximum intensity projection; (2) the areas of the defect on axial slices; and (3) the threshold and segmentation of the region of interest. The values obtained from each method using different acquisition protocols were compared with the real volume of the wax (gold standard) using ANOVA and Tukey's test.Methods 2 and 3 did not differ from the gold standard (p 0.05). Conversely, Method 1 presented statistically significant overestimated values (p 0.01). No differences were found among the different FOV and voxel sizes (p 0.05).CBCT volumes proved reliable for the volumetric assessment of alveolar cleft defects, when using Methods 2 and 3 regardless of FOV and voxel sizes. It may be possible to improve surgical planning and outcomes by knowing the exact volume of grafting material needed prior to the surgical intervention.

The aim of this study was to compare the accuracy of cone beam CT (CBCT) with intraoral radiographs for detection of occlusal caries.A set of 60 extracted teeth were imaged using a Sirona Galileos CBCT system (Sirona Dental Systems, Bensheim, Germany) and an intraoral Planmeca® system (Planmeca OY, Helsinki, Finland). Six observers looked at both modalities and used a five-point confidence scale to evaluate presence or absence of occlusal caries. Histology was used as the gold standard. Receiver operating characteristic analysis and weighted kappa statistics were used for statistical analysis. Differences in the area under the curve (AUC) values between observers and modalities were analysed using analysis of variance (ANOVA). Differences in sensitivity and specificity were analysed using the Wilcoxon test. Interobserver and intraobserver reliability was assessed by weighted kappa scores.The mean value and standard deviation of AUC was 0.719 ± 0.038 for CBCT and 0.649 ± 0.062 for the intraoral radiographs. The ANOVA results demonstrated that there was no significant difference between the modalities and the observers. The interobserver kappa for pairs of observers ranged from fair to substantial for bitewings (0.244-0.543) and CBCT (0.152-0.401). Four out of six observers reported higher sensitivity but lower specificity with CBCT. The Wilcoxon exact p-value showed no difference in sensitivity (0.175) or specificity (0.573) between the two modalities.Based on the results we conclude that the Sirona CBCT unit cannot be used for the sole purpose of looking at occlusal caries.

A Position Paper Subcommittee of the American Academy of Oral and Maxillofacial Radiology (AAOMR) reviewed the literature since the original position statement on selection criteria for radiology in dental implantology, published in 2000. All current planar modalities, including intraoral, panoramic, and cephalometric, as well as cone beam computed tomography (CBCT) are discussed, along with radiation dosimetry and anatomy considerations. We provide research-based, consensus-derived clinical guidance for practitioners on the appropriate use of specific imaging modalities in dental implant treatment planning. Specifically, the AAOMR recommends that cross-sectional imaging be used for the assessment of all dental implant sites and that CBCT is the imaging method of choice for gaining this information. This document will be periodically revised to reflect new evidence.

In a 2008 article on cone beam volumetric tomography (CBVT) and dentoalveolar applications, Tyndall and Rathore wrote: "It is in the area of endodontic applications that the literature has proved most fruitful to date." This statement is even truer today than in 2008. A review of the literature has demonstrated that, in many cases, CBVT is more efficacious than traditional forms of 2-D imaging. Endodontic applications of CBVT include the diagnosis of periapical lesions due to pulpal inflammation, identification, and localization of internal and external resorption, the detection of vertical root fractures, the visualization of accessory canals, and elucidation of the causes of non-healing endodontically treated teeth. Prior to 2008, most published articles on CBVT applications in endodontics were either case reports or in vitro studies. Since that time more well designed clinically related scholarly activity has been published. This article attempts to survey the field of CBVT applications in endodontics and provide the readers with an overview of what has been found. The authors hope that this knowledge will form a foundation for appropriate clinical decision making with specific reference to selection criteria for the endodontic applications of CBVT.

The value of computer-aided implant planning using cone-beam computerized tomography (CBCT) for single immediate implants was explored. Eighteen patients requiring extraction of a tooth followed by a single immediate implant were enrolled. Small volume preoperative CBCT scans were used to plan the position of the implant. A taper screwed–type implant was immediately placed into a fresh socket using only the final 1 or 2 drills for osteotomy. Postoperative CBCTs were used for the analysis of actual implant placement positioning. Measurements of the planned and the actual implant position were made with respect to their position relative to the adjacent teeth. Mesio-distal displacements and the facial-lingual deviation of the implant from the planned position were determined. Changes in the angulation of the planned and actual implant position in relation to the clinical crown were also measured. To statistically summarize the results, box plots and 95% CIs for means of paired differences were used. The analysis showed no statistical difference between the planned position and final implant placement position in any measurement. The CBCT scans coupled with the computer-aided implant planning program along with a final 1-to-2 drill protocol may improve the accuracy of single immediate implant placement for taper screwed–type implants.

The aim of this study was to propose a classification for unilateral cleft lip and palate (UCLP) malformations based on cone beam computed tomography (CBCT) images, as well as to estimate the amount of bone necessary for grafting, and to evaluate the relationship of this volume with scores obtained using the classification. CBCT images of 33 subjects with UCLP were evaluated according to gap, arch, nasal, and dental parameters (GAND classification). Additionally, these defects were segmented and the amount of graft needed for alveolar bone grafting was estimated. The reproducibility of GAND classification was analyzed by weighted kappa test. The association of volume assessment with the classification (gap and nasal parameters) was verified using analysis of variance, while the intra-observer agreement was analyzed using the intra-class correlation coefficient. The intra-observer reproducibility of the classification ranged from 0.29 to 0.92 and the inter-observer agreement ranged from 0.29 to 0.91. There were no statistically significant values when evaluating the association of the volume with the classification ( P > 0.05). The GAND classification is a novel system that allows the quick estimation of the extent and complexity of the cleft. It is not possible to estimate the amount of bone needed for alveolar bone grafting based on the classification; individualized surgical planning should be done for each patient specifically.

Pretreatment diagnosis of mandibular asymmetry in orthognathic surgery patients can be improved by quantitative shape modeling and analysis. The UNC SPHARM-PDM (University of North Carolina Spherical Harmonics-Point Distribution Model) toolbox was applied to a cohort of patients and the results were evaluated.Three-dimensional (3D) virtual surface models are constructed from CBCT scans of each patient in the cohort by segmentation. Mirroring on a sagittal arbitrary plane is used to flip the left and right sides of each image. An automatic voxel-based registration on the cranial base is used to align the volume and its mirror for comparison. SPHARM-PDM is used to compute correspondent models for each hemimandible and the mirror of the contralateral side. Procrustes analysis was used to evaluate discrepancies between each pair of models to assess asymmetry. Mandibular asymmetry was also located and quantified by computing corresponding surface distances between each hemimandible (left and right sides) and the mirror of the contralateral side.There were no statistically significant differences in surrogates for mandibular asymmetry assessment based on right or the left side mirroring. Those surrogates are the rotational and translational differences between each hemimandible and the mirror of the contralateral side in 3 planes of space (the absolute values of Procrustes registration output in 6 degrees of freedom). Absolute and signed distance maps between each hemimandible and the mirror of the contralateral side located and quantified areas of asymmetry diagnosis for each patient. Even though mandibular condyle asymmetry was observed in 8% of the cases and mandibular asymmetry along areas of the ramus and mandibular corpus was noted in 17.8% of the cases, the remaining 74.2% showed generalized morphological and positional asymmetry at the condyle, the ramus and mandibular corpus.Three-dimensional diagnosis of mandibular asymmetry revealed the complex involvement of morphological components of the mandible and the heterogeneous nature of this clinical condition. SPHARM-PDM has a promising role in the individual diagnosis and quantification of mandibular asymmetry.

Objective To evaluate the type and prevalence of incidental findings from cone beam computed tomography (CBCT) of the maxillofacial region. Findings are divided into those that require (i) intervention/referral, (ii) monitoring, and (iii) no further evaluation. Methods Three hundred consecutive CBCT scans conducted in the University of North Carolina School of Dentistry Oral and Maxillofacial Radiology Clinic from January 1 to August 31, 2008 were retrospectively reviewed. Findings were categorized into airway, soft tissue calcifications, bone, temporomandibular joint (TMJ), endodontic, dental developmental, and pathological findings. Results A total of 272 scans revealed 881 incidental findings (3.2 findings/scan). The most prevalent was airway findings (35%) followed by soft tissue calcifications (20%), bone (17.5%), TMJ (15.4%), endodontic (11.3%), dental developmental (0.7%), and pathological (0.1%). 16.1% required intervention/referral, 15.6% required monitoring, and the remainder (68.3%) required neither. Conclusion This study underscores the need to thoroughly examine all CBCT volumes for clinically significant findings within and beyond the region of interest.

The aims of this study were to determine whether lesion features appear differently on panoramic radiography (PAN) and cone beam computed tomography (CBCT), and whether the use of CBCT affects diagnostic accuracy and observers' confidence in comparison with PAN.Three oral and maxillofacial radiologists reviewed 33 sets of PAN images and CBCT volumes of biopsy-proven lesions. They described 12 different lesion features and provided up to 3 ranked differential diagnoses, as well as their confidence with respect to those diagnoses. Their confidence was weighted by the rank at which the correct diagnosis was provided.Odds ratios (ORs) were statistically significant for border definition (OR = 5.45; P = .004), continuity of border cortication (OR = 0.34; P = .035), effect on neurovascular canals (OR = 6.38; P = .043), expansion (OR = 18.56; P .001), cortical thinning (OR = 30.22; P .001), and cortical destruction (OR = 9.80; P .001). There was no association between the 2 modalities and the rank at which the correct differential diagnoses were made or the observers' weighted confidence.Before acquiring a CBCT scan to aid in the diagnosis of an intraosseous lesion, clinicians should consider the diagnostic information that is expected to be gained. In this study, although there were differences between PAN and CBCT with respect to some lesion features, CBCT did not help improve diagnostic accuracy.

Objective: To determine the reliability of obtaining two-dimensional cephalometric measurements using two virtual head orientations from cone-beam computed tomography (CBCT) models. Materials and Methods: CBCT scans of 12 patients (6 class II and 6 class III) were randomly selected from a pool of 159 patients. An orthodontist, a dental radiologist, and a third-year dental student independently oriented CBCT three-dimensional (3D) renderings in either visual natural head position (simulated NHP) or 3D intracranial reference planes (3D IRP). Each observer created and digitized four CBCT-generated lateral cephalograms per patient, two using simulated NHP and two using 3D IRP at intervals of at least 3 days. Mixed-effects analysis of variance was used to calculate intraclass correlation coefficients (ICCs) and to test the difference between the orientations for each measure. Results: ICC indicated good reliability both within each head orientation and between orientations. Of the 50 measurements, the reliability coefficients were ≥0.9 for 45 measurements obtained with 3D IRP orientation and 36 measurements with simulated NHP. The difference in mean values of the two orientations exceeded 2 mm or 2° for 14 (28%) of the measurements. Conclusions: The reliability of both virtual head orientations was acceptable, although the percentage of measurements with ICC >0.9 was greater for 3D IRP. This may reflect the ease of using the guide planes to position the head in the 3D IRP during the simulation process.

This case report documents the dental management of two permanent maxillary central incisors with a severe intrusive labial luxation injury in conjunction with one complicated and one uncomplicated crown fracture. Additionally, there was a fracture of the labial cortical plate which remained attached to the overlying soft tissue. The two affected teeth and fractured labial plate of bone were surgically repositioned and splinted. Endodontic therapy was completed on the two incisors and the two crown fragments, which had been maintained wet, were re-attached. The report describes a multidisciplinary approach to trauma management and case progress over a 20-month period.

Objective To evaluate reliability in 3-dimensional (3D) landmark identification using cone-beam computerized tomography (CBCT). Study design Twelve presurgery CBCTs were randomly selected from 159 orthognathic surgery patients. Three observers independently repeated 3 times the identification of 30 landmarks in the sagittal, coronal, and axial slices. A mixed-effects analysis of variance model estimated the intraclass correlations (ICC) and assessed systematic bias. Results The ICC was >0.9 for 86% of intraobserver assessments and 66% of interobserver assessments. Only 1% of intraobserver and 3% of interobserver coefficients were Conclusion Overall, the intra- and interobserver reliability was excellent. Three-dimensional landmark identification using CBCT can offer consistent and reproducible data if a protocol for operator training and calibration is followed. This is particularly important for landmarks not easily specified in all 3 planes of space.

Background Bisphosphonates are used widely to manage skeletal disorders resulting from malignancies that destroy bone and from some metabolic bone diseases. A strong association between bisphosphonate treatment and the appearance of painful exposed nonvital bone in the mandible and maxilla after oral surgery has been reported in the last decade. Extensive reviews have appeared in the dental literature regarding bisphosphonate-related osteonecrosis of the jaws (BRONJ), including protocols for diagnosis, management and diagnostic imaging for early detection; feature definition; and determination of extent of the disease. Case Descriptions The authors provide three case reports to show the contrast in treatment outcomes and morbidity in patients with BRONJ. The cases involved diagnostic imaging modalities commonly used in the practice of dentistry: panoramic radiography and cone-beam volumetric computed tomography. Clinical Implications These case reports demonstrate the usefulness of dental diagnostic imaging in the detection and management of BRONJ, corroborate the increasing number of reports regarding high levels of morbidity associated with various BRONJ treatments, and underscore the danger of performing invasive dental procedures for patients receiving bisphosphonate therapy.

Objective The objective of this study was to compare the diagnostic accuracy of 3 extraoral imaging modalities with an intraoral bitewing radiograph for proximal caries detection. Study design Three modalities of Cranex TOME scanograms, x-ray film and DenOptix photostimulable phosphor plates with and without digital enhancement, were compared with Insight intraoral radiographs for proximal caries detection. Nine observers evaluated images of the proximal surfaces of 45 extracted posterior teeth. The presence or absence of caries was scored using a 5-point confidence scale. The ground truth was determined from histological sections. Responses were evaluated by repeated measures analysis of variance (ANOVA) for areas under receiver operating characteristic (ROC) curves (A z ). Results Repeated measures ANOVA (at α = 0.05) demonstrated significant differences among modalities ( P = .041). Paired t tests with Bonferroni correction demonstrated that Insight was superior to only unenhanced digital scanograms ( P = .003). Mean A z scores (±SD) were 0.73 (±0.08) for Insight, 0.65 (±0.06) for screen/film scanogram, 0.64 (±0.04) for unenhanced digital scanogram, and 0.66 (±0.07) for enhanced digital scanogram. Conclusions The performances of film-based and enhanced digital scanograms were not statistically different from Insight film for proximal caries detection. Unenhanced digital scanograms exhibited a statistically significant lower diagnostic accuracy than Insight film.

Purpose This study was designed to optimize a new radiographic modality known as tuned aperture computed tomography (TACT) for cross-sectional imaging of implant sites in human dry mandibles. Materials and Methods Five imaging modalities were compared for image quality and measurement accuracy: (1) conventional hypocycloidal tomograms, (2) TACT images reconstructed using the average method produced using a linear x-ray source movement, (3) TACT images reconstructed using the average method produced using a multidirectional x-ray source movement, (4) minimally reconstructed TACT images without a fiducial marker at the site of interest, and (5) minimally reconstructed TACT images with a fiducial marker at the site of interest. Results The extended Mantel-Haenszel mean score statistic was used to investigate the influence of modality on subjective image quality. A statistically significant difference for certain types of TACT images and multidirectional tomography (P < 0.0001) was observed. Linear TACT and multmin TACT were rated as significantly better than other image modalities (P < 0.0009), whereas multidirectional tomography was rated as being significantly worse than other radiographic modalities (P < 0.0001). For the quantitative assessment, data were normalized and analyzed statistically through a paired-comparisons t test. For each modality, the accuracy for maximum height and height was significantly different from ground truth (P < 0.05). Conclusion The qualitative data suggest that visibility of structures important to the choice of implant location and dimension were seen better with certain TACT methods. Quantitative differences from ground truth (actual measurements of the bone-absolute truth) were clinically negligible. TACT appears to offer the potential of superior image quality over the status quo.

An in vitro observer study of the detection of interproximal caries by local CT.Detection of caries by means of conventional two-dimensional (2D) digital radiography and by two CT modalities was compared. Ground truth was obtained from histological examination of the sectioned teeth. Twenty-three extracted teeth (46 surfaces) were placed in groups of six in two dry mandibles. The observers (n=10) scored the proximal surfaces for the presence of caries on a 1-5 confidence scale. Data analysis used analysis of variance (a General Linear Model). Observer and method were entered into the model as within-subject variables and lesion depth was entered as a between-subjects variable.The analysis showed observer, method and lesion depth effects as well as several interaction effects to be significant. Observers performed significantly better with the vertically reformatted CT slices than with conventional radiographs (P=0.025). Furthermore, there were significant differences between observers, and several interactions were found to be significant. This means that although the reformatted slices performed best overall, this performance differed significantly depending on observer and on lesion depth.Vertically reformatted CT slices obtained with local CT performed significantly better than conventional 2D digital radiographs in visually detecting caries. Axial slices did not perform better than conventional radiographs. When vertically reformatted slices are used, local CT is a promising tool for the detection of interproximal caries.

To study the effect of lossy image compression on caries detection. Null hypothesis states no difference in caries detection efficacy among observers using original digital images versus images compressed at various rates of compression.Digital images of 41 extracted posterior teeth were obtained with a storage phosphor DenOptix (Gendex DenOptix Imaging system) system. Images were exported in Tagged Image File Format (TIFF) and compressed with Joint Photographic Experts Group File Interchange Format (JFIF), as provided by the software of the imaging system. The compressions options JFIF100%, JFIF75% and JFIF50% resulted in reducing the image size to 1:2, 1:11 and 1:16, respectively. Eight observers evaluated the presence or absence of caries on a 5-point confidence scale. The actual caries status of each proximal surface was determined by ground section histology. Responses were evaluated by receiver operating characteristic (ROC) analysis. Areas under the curves (Az) were assessed using analysis of variance (ANOVA).The mean Az scores were 0.85 for original/uncompressed images, and 0.89 for JFIF100%, 0.88 for JFIF75% and 0.88 for JFIF50% images. These differences were not statistically significant (P = 0.26). Differences between observers were also not statistically significant (P = 0.12).JFIF compression at the level of 1:16 can be used without significant deterioration in diagnostic accuracy for proximal caries detection.

The purpose of this study was to determine if there was a significant difference in the diagnostic quality of the initial full-mouth series (FMS) exposed by first-year dental students after viewing a Computer Assisted Instruction (CAI) module on radiographic technique as compared to those who did not and to determine if students who used the CAI module expressed a preference to using it and would recommend its use prior to exposure. Fifty-nine first-year dental students were randomly selected and assigned to two groups (students who did not view a CAI CD and students who did) before exposing their initial FMS on a Dental X-ray Training and Teaching Replica (DXTTR). For each radiographic series, a radiology faculty member determined the total number of error points based on performance criteria. The Wilcoxon Rank Sum Test was used to determine significance between the two groups, p = .05. After exposing the FMS, students in the second group completed a questionnaire to assess their preference for using the CAI CD. The Sign Rank Test was used to determine preference, p = .05. No significant difference in error points were found to exist between the two groups. Dental students who reviewed the CAI preferred using it and would recommend it to others before exposing their FMS.

Tuned Aperture Computed Tomography or TACT is a relatively new technique that transforms correlated two-dimensional images into a three-dimensional display. Associating TACT with digital subtraction radiography (TACT-DSR) may enhance its use in the detection of diseases. This study aims to assess observer performance in the task of detecting simulated bone-gain in periodontal defects, comparing conventional and TACT DSR. Buccal, lingual and proximal pericrestal bony defects in a human dry skull were imaged with and without increments of crushed-bone and wax mixtures using standardized vertical bitewing projections, acquired with an intraoral digital receptor in a tomographic X-ray machine. One hundred and twenty pairs of baseline and follow-up images were obtained for each imaging modality. Post-acquisition processing including image-registration, density-correction and subtraction operation were applied to both transmission images and TACT-slices. Eight calibrated observers evaluated the presence or absence of pericrestal bone-gain using a 5-point confidence scale. Details about the location of periodontal defects and the amount of bone-gain for each subtracted image were recorded and used in the statistical analysis. Observer performance and study design factors were analyzed by means of receiver operating characteristic (ROC) curve analysis and ANOVA. Mean values of areas under ROC curves for bone-gain detection performance were 0.82 for conventional DSR and 0.90 for TACT-DSR. TACT-DSR provided statistically superior detection performance of simulated periodontal bone-gain over conventional DSR for tooth-obscured defects (p = 0.001) and for the smallest bone mass (p = 0.024). The findings support TACT-DSR's potential to provide greater sensitivity and technique flexibility in detecting periodontal bone-gain than standard DSR.

Objective. The objective of this study was to compare the diagnostic efficacy of tuned-aperture computed tomography (TACT) and conventional film for the detection of simulated periodontal defects. Study Design. Periodontal defects were created in 15 premolar-molar interproximal sites selected from 8 cadaver jaw segments. Ten observers viewed 45 image pairs (baseline and follow up) in 4 TACT modalities and film to assess the presence of defect. The TACT modalities were 1st and 2nd generation prototype systems (TACT-1 and TACT-2) with circular (C) and random (R) distribution patterns of source projection (TACT-1C, TACT-1R, TACT-2C, TACT-2R). Observer performance and related factors were analyzed by using receiver operating characteristic and analysis of variance. Results. Mean Az values were 0.64 for film, 0.74 for TACT-1C, 0.82 for TACT-1R, 0.64 for TACT-2C, and 0.69 for TACT-2R. TACT-1R was significantly better than film (P

The aim of this study was to compare the volume of nasopharyngeal airways of patients with unilateral cleft lip and palate (UCLP) with a control (noncleft) group of subjects.Retrospective case-control study.The sample consisted of 45 subjects, 30 with UCLP who underwent cone beam computed tomography (CBCT) exams as part of their workups for alveolar bone graft and 15 noncleft subjects seeking orthodontic care who obtained CBCT for diagnostic purposes. The three-dimensional volumes of nasal (NV) and oropharyngeal (PV) airways of these subjects were assessed separately using Mimics software by one well-calibrated evaluator. The images were rendered, and the volumes were measured in cm(3).The mean PV of the UCLP subjects was 6.7 cm(3) and the mean NV was 10.3 cm(3). The control group presented with a mean PV of 8.1 cm(3) and a mean NV of 11.6 cm(3). Student t test showed no statistically significant difference for PV (P = 0.10) or NV (P = 0.23) when comparing cleft and noncleft subjects.Evaluation of the nasopharyngeal airways revealed that the NV and PV airways showed no difference between the cleft and noncleft subjects. It is interesting to postulate that the reported nasal abnormalities of the cleft patients do not produce a significant measurable effect on the overall volume, at least as shown in our study sample. In addition, the nasopharyngeal airways of patients are not larger than those of age-matched controls, at least at the ages that were sampled, after cleft palate repair.

Fractal analysis was used to quantify changes in trabecular bone induced through the use of a rat tail-suspension model to simulate microgravity-induced osteopenia. Fractal dimensions were estimated from digitized radiographs obtained from tail-suspended and ambulatory rats. Fifty 4-month-old male Sprague-Dawley rats were divided into groups of 24 ambulatory (control) and 26 suspended (test) animals. Rats of both groups were killed after periods of 1, 4, and 8 weeks. Femurs and tibiae were removed and radiographed with standard intraoral films and digitized using a flatbed scanner. Square regions of interest were cropped at proximal, middle, and distal areas of each bone. Fractal dimensions were estimated from slopes of regression lines fitted to circularly averaged plots of log power vs. log spatial frequency. The results showed that the computed fractal dimensions were significantly greater for images of trabecular bones from tail-suspended groups than for ambulatory groups (p < 0.01) at 1 week. Periods between 1 and 4 weeks likewise yielded significantly different estimates (p < 0.05), consistent with an increase in bone loss. In the tibiae, the proximal regions of the suspended group produced significantly greater fractal dimensions than other regions (p < 0.05), which suggests they were more susceptible to unloading. The data are consistent with other studies demonstrating osteopenia in microgravity environments and the regional response to skeletal unloading. Thus, fractal analysis could be a useful technique to evaluate the structural changes of bone.

This study compared the ability of the TACT system of imaging and conventional D-speed film to detect simulated resorptive defects in cadaver teeth and jaws. Mandibular human jaw blocks were prepared and then split through the teeth in a mesial to distal direction so that the mandibular halves could be opened and reassembled when necessary. One half of each of 42 teeth was extracted, and areas on the tooth and corresponding bone identified to be studied. The jaws were opened and reassembled after no defects or after defects of different sizes (0.25, 0.5, 1.0, 2.0 mm) were placed in the tooth and the corresponding bone at predetermined evaluation areas. The teeth were imaged after each stage with conventional D-speed film using a standard paralleling technique, and with a modified orthopantomograph OP100 machine using a Schick #2 size CCD sensor as the image receptor. The source images were registered and TACT slices were generated using TACT Workbench Software. Three observers were asked to identify the presence of resorptive defects in the conventional film group and the TACT image group using specific criteria. TACT imaging was statistically superior to conventional radiographs in detecting defects that were present (Wilcoxon matched pairs signed ranks test P = 0.003). This was true for all sizes of defects examined. There was no difference between the two modalities when a defect was not present.

Amelogenesis imperfecta, a group of hereditary conditions primarily affecting the enamel, has been associated with dental anomalies, including taurodontism, congenitally missing teeth, delayed eruption, crown resorption, and abnormal enamel density. The purpose of this study was to assess the prevalence of these anomalies in an amelogenesis imperfecta population. The study group consisted of members of 9 unrelated families--22 family members with amelogenesis imperfecta and 13 unaffected family members. Panoramic radiographs were evaluated for taurodontism, congenitally missing teeth, delayed tooth eruption, pathologic dental resorption, pulp calcification, and radiographic enamel density. The prevalence of taurodontism was similar in people with amelogenesis imperfecta and normal people; all of the remaining parameters were more commonly observed in people with amelogenesis imperfecta. The radiographic enamel density was quantitatively reduced in teeth affected by amelogenesis imperfecta in comparison with teeth with normal enamel. These findings suggest that some of the features associated with amelogenesis imperfecta result from abnormal enamel formation (eg, decreased enamel density, crown resorption) whereas others may occur as a result of expression of the genetic mutation in cells other than ameloblasts (eg, abnormal eruption, pulp calcification).

Objective. The purpose of this study was to compare the diagnostic performance of conventional digital images and tuned aperture computed tomography (TACT) slices in caries detection through use of cathode-ray tube monitor and laptop displays. Study design. Forty-two extracted posterior teeth were mounted and imaged with a direct digital radiography system. Conventional digital bitewing projections and TACT slices were acquired. Images were viewed on a high-resolution cathode-ray tube monitor and on an active-matrix laptop display. Eight observers assessed caries status of occlusal and proximal surfaces of the teeth using all combinations of image and display modality. Observers’ assessments were compared with the results of histologic examination of tooth sections. Possible differences in receiver operating characteristic curve areas among displays, image modalities, observers, and surfaces were analyzed by means of analysis of variance. Results. There was no statistically significant difference between the diagnostic performances provided by the cathode-ray tube monitor and laptop displays in caries detection ( P = .588). In addition, the performances of digital images and TACT slices were not significantly different ( P = .843). Conclusions. Modern active-matrix laptop displays provide diagnostic quality for caries detection comparable to that obtainable with cathode-ray tube monitors. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;88:234-8)

This study tests the hypothesis that estimates of changes in bone mass derived from subtraction data obtained in accord with published methods are independent of the spatial aspect of the lesion being evaluated when calibrations are performed independently. Nineteen sliver-shaped bone chips ranging in mass from approximately 1 to 35 mg were orientated with broad side parallel to the facial surface of a hemisectioned dry human mandible and radiographed using conventional exposure parameters on conventional E-speed dental X-ray film. Also attached to the film was a standardized aluminium calibration wedge that facilitated quantitative analysis of resulting subtraction data using established methodology. The effects of scatter were simulated by the addition of a 1-cm-thick slab of tissue-equivalent plastic. A second series of exposures then was produced using the same respective spatial chip locations and projection geometries but each chip was reorientated such that its broad side was now positioned perpendicular to the mandibular facial surface. Finally, a comparable series of control exposures was produced without any chips or calibration wedge to facilitate subtraction. When paired bone estimates derived from the two chip orientations were compared (paired comparisons) using Student's t-test, a statistically significant difference (p < 0.05) was observed. These results also were tested for statistical significance using the non-parametric Wilcoxon test. As with the parametric analysis, the discrepancy between the parallel and perpendicular mass estimates was found to statistically significant (p < 0.05). The methods employed in this investigation thus resulted in bone mass estimates that varied significantly depending upon lesion orientation.

Objective. The objective of this study was to evaluate the accuracy of alveolar crestal bone detection in a comparison of unenhanced and enhanced Sidexis (Siemens Medical Systems, Inc., Bensheim, Germany) digital images with Ektaspeed Plus (Eastman Kodak, Rochester, N.Y.) films by means of receiver operating characteristic analysis. Study Design. More than 100 proximal and furcal areas in the anterior and posterior areas of the mandible and maxilla of each of three tissue-equivalent human skull phantoms were imaged with film, direct digital images, and contrast- and brightness-enhanced digital images. Alveolar crest status was assessed by a consensus panel of three experts who used the Delphi method and evaluated information from all of the imaging modalities concurrently. Five observers assessed all images for the presence or absence of crestal bone loss using a five-point confidence scale. Receiver operating characteristic curves were generated, and calculated areas (Az) were analyzed by means of analysis of variance. Results. The expert panel determined that of 106 crestal areas, 48 were disease free and 58 exhibited bone loss greater than 2 mm apical to the cemento-enamel junction. Analysis of variance of observer Az scores showed significant differences among readers (p < 0.001) and among readings (p = 0.027), but not among modalities (p = 0.435). Mean Az values for the different modalities were as follows: Sidexis, 0.70; enhanced Sidexis, 0.71; Ektaspeed Plus films, 0.735. Conclusion. The Sidexis digital imaging system was not significantly different from Ektaspeed Plus film for crestal bone evaluation in this in vitro study.

This in vitro investigation compares biplanar (sagittal and coronal) temporomandibular joint images produced by multidirectional tomographic and panoramic techniques for diagnostic accuracy in the detection of simulated degenerative lesions. A series of dentin chips placed at four locations on the head of a temporomandibular joint condyle in a dried human skull were imaged with tomographic and panoramic modalities. Equal numbers of images with and without chips were scored by four examiners with the use of confidence levels for presence or absence of the lesion. To assess intra-examiner reliability, each examiner viewed one of the modalities twice. Responses were assessed by generating receiver operating characteristic curves and analyzing the area (Az) under the curves with analysis of variation methods. Biplanar tomography provided significantly more accurate assessment of condylar lesions than biplanar panoramic images (p=0.007). No statistical difference by location (p=0.592) was found. The effects of observer and repeated observation were marginally significant at p=0.046 and p=0.030, respectively.

Immediate access to off-site expert diagnostic consultants regarding unusual radiographic findings or radiographic quality assurance issues could be a current problem for private dental practitioners. Teleradiology, a system for transmitting radiographic images, offers a potential solution to this problem. Although much research has been done to evaluate feasibility and utilization of teleradiology systems in medical imaging, little research on dental applications has been performed. In this investigation 47 panoramic films with an equal distribution of images with intraosseous jaw lesions and no disease were viewed by a panel of observers with teleradiology and conventional viewing methods. The teleradiology system consisted of an analog video-based system simulating remote radiographic consultation between a general dentist and a dental imaging specialist. Conventional viewing consisted of traditional viewbox methods. Observers were asked to identify the presence or absence of 24 intraosseous lesions and to determine their locations. No statistically significant differences in modalities or observers were identified between methods at the 0.05 level. The results indicate that viewing intraosseous lesions of video-based panoramic images is equal to conventional light box viewing.