Interpretation of periapical lesions comparing conventional, direct digital, and telephonically transmitted radiographic images

Efficacy of imaging techniques for the diagnosis of apical periodontitis: A systematic review

BACKGROUND

Apical periodontitis (AP) is a chronic inflammatory response of microbial aetiology. Pathological changes associated with AP may not be visible on radiographic images and may linger without causing any symptoms. Clinicians rely mostly on clinical examination and imaging techniques to establish a diagnosis.

OBJECTIVES

The aim of this review was to answer the following question using the PICO format: In the adult human permanent dentition (P), what is the efficacy of diagnostic imaging of the periapical tissues (I) using histopathology as a reference standard (C) in the diagnosis of apical periodontitis, in terms of diagnostic accuracy (O).

METHODS

MEDLINE, EMBASE, Scopus and Cochrane Library were searched for English articles published through October 2021. At least two independent reviewers evaluated the study design, imaging modality used, histopathological assessment, outcome measures, results and conclusions for each article. The risk of bias was assessed using the Quality Assessment Tool for Diagnostic Accuracy Studies-2.

RESULTS

The initial search strategy identified 544 articles. Seven articles were included for analysis in the final review, all of which involved tissue samples obtained from cadavers. No clinical studies were identified that met the eligibility criteria. A consistently low sensitivity score and negative predictive value were reported for periapical radiography, especially in comparison to CBCT, which scored highly. Both modalities achieved high scores for specificity and positive predictive value. Diagnostic accuracy of CBCT was lower for root-filled teeth in comparison to non-root-filled teeth.

DISCUSSION

Assessment of the periapical tissues using periapical radiographs was shown to have a low to moderate agreement with the histopathological assessment. CBCT was reported to be more accurate than PR and demonstrated a good agreement with histopathology, especially for non-root-filled teeth.

CONCLUSIONS

This review identified a need for greater standardization in methodology and reporting, and as the findings are based on cadaver studies, their clinical relevance must be interpreted with caution.

REGISTRATION

PROSPERO (CRD42021272147).

A comparative study on diagnostic accuracy of colour coded digital images, direct digital images and conventional radiographs for periapical lesions - an in vitro study

OBJECTIVES

The identification and radiographic interpretation of periapical bone lesions is important for accurate diagnosis and treatment. The present study was undertaken to study the feasibility and diagnostic accuracy of colour coded digital radiographs in terms of presence and size of lesion and to compare the diagnostic accuracy of colour coded digital images with direct digital images and conventional radiographs for assessing periapical lesions.

MATERIALS AND METHODS

Sixty human dry cadaver hemimandibles were obtained and periapical lesions were created in first and second premolar teeth at the junction of cancellous and cortical bone using a micromotor handpiece and carbide burs of sizes 2, 4 and 6. After each successive use of round burs, a conventional, RVG and colour coded image was taken for each specimen. All the images were evaluated by three observers. The diagnostic accuracy for each bur and image mode was calculated statistically.

RESULTS

Our results showed good interobserver (kappa > 0.61) agreement for the different radiographic techniques and for the different bur sizes. Conventional Radiography outperformed Digital Radiography in diagnosing periapical lesions made with Size two bur. Both were equally diagnostic for lesions made with larger bur sizes. Colour coding method was least accurate among all the techniques.

CONCLUSION

Conventional radiography traditionally forms the backbone in the diagnosis, treatment planning and follow-up of periapical lesions. Direct digital imaging is an efficient technique, in diagnostic sense. Colour coding of digital radiography was feasible but less accurate however, this imaging technique, like any other, needs to be studied continuously with the emphasis on safety of patients and diagnostic quality of images.

Clinical usefulness of teleradiology in general dental practice

Purpose

This study was performed to investigate the clinical usefulness of teleradiology in general dental practice.

Materials and Methods

Two hundred and seventy five cases were submitted for inquiry to the case presentation board of the website of The Korean Academy of Oral and Maxillofacial Radiology for a 5 year periods. The diagnosis results of those cases were analyzed according to the disease classification, the correlation with the patient's chief complaint, the necessity of additional examinations or treatments, the image modalities, and the number of dentists inquiring.

Results

Differential diagnoses of normal anatomic structures were the most frequently submitted cases, covering 15.6% of all cases. Among 275 cases, 164 cases required no additional treatments or examinations. Panoramic radiographs were the most frequently submitted images, accounting for 248 inquiries. The 275 cases were submitted by 96 dentists. Fifty-two dentists wrote one inquiry, and 44 inquired 2 or more times. The average inquiry number of the latter group was 5.0 cases.

Conclusion

A teleradiology system in general dental practice could be helpful in the differential diagnosis of common lesions and reduce unnecessary costs.

Imaging techniques in endodontics: an overview

This review provides an overview of the relevance of imaging techniques such as, computed tomography, cone beam computed tomography, and ultrasound, to endodontic practice. Many limitations of the conventional radiographic techniques have been overcome by the newer methods. Advantages and disadvantages of various imaging techniques in endodontic practice are also discussed.

Detection of vertical root fractures using digitally enhanced images: reverse-contrast and colorization

Root fracture diagnosis is a clinical difficulty that in most cases can only be detected through radiography. The objective of this study was to compare the diagnostic accuracy of two types of digitally enhanced images (reverse-contrast and colorization) with original digital radiographies in detecting experimental root fractures. Two hundred extracted single-rooted human teeth were endodontically instrumented and then divided in two groups, one control group and one test group, including fractured teeth. Vertical root fractures were experimentally made in the fractured group. The digital image of each tooth was taken, using the paralleling technique. There were three groups of images: (i) original, (ii) reverse contrast, and (iii) colorized. Three experienced dental specialists examined the images with no prior knowledge of the distribution of the root fractures. Two-way analysis of variance was used to assess the differences in accuracy, sensitivity, and specificity of each technique in detecting root fractures. Cohen's kappa coefficients were calculated to investigate the degree of interobserver agreement. The accuracy, sensitivity, and specificity of original images were 67.4%, 66.7%, and 68%, respectively; these amounts were 61.5%, 61%, and 65.5% in reverse contrast images and 66.4%, 70.7%, and 62% in colorized digital radiography. The original images had the best inter observer kappa coefficients (between 0.45 and 0.55). The results showed that the accuracy of original images is better than reverse contrast and colorized images. Use of reverse-contrast and colorization digital images in root fracture detection should be regarded as an adjunct to other diagnostic methods not as a highly critical diagnostic aid.

Endodontic radiography: who is reading the digital radiograph?

INTRODUCTION

Digital radiographic imaging systems have undergone tremendous improvements since their introduction. Advantages of digital radiographs over conventional films include lower radiation doses compared with conventional films, instantaneous images, archiving and sharing images easily, and manipulation of several radiographic properties that might help in diagnosis.

METHODS

A total of 6 observers including 2 endodontic residents, 3 endodontists, and 1 oral radiologist evaluated 150 molar digital periapical radiographs to determine which of the following conditions existed: normal periapical tissue, widened periodontal ligament, or presence of periapical radiolucency. The evaluators had full control over the radiograph's parameters of the Planmeca Dimaxis software program. All images were viewed on the same computer monitor with ideal vie-wing conditions. The same 6 observers evaluated the same 150 digital images 3 months later. The data were analyzed to determine how well the evaluators agreed with each other (interobserver agreement) for 2 rounds of observations and with themselves (intraobserver agreement).

RESULTS

Fleiss kappa statistical analysis was used to measure the level of agreement among multiple raters. The overall Fleiss kappa value for interobserver agreement for the first round of interpretation was 0.34 (P < .001). The overall Fleiss kappa value for interobserver agreement for the second round of interpretation was 0.35 (P < .001). This resulted in fair (0.2-0.4) agreement among the 6 raters at both observation periods. A weighted kappa analysis was used to determine intraobserver agreement, which showed on average a moderate agreement.

CONCLUSIONS

The results indicate that the interpretation of a dental radiograph is subjective, irrespective of whether conventional or digital radiographs are used. The factors that appeared to have the most impact were the years of experience of the examiner and familiarity of the operator with a given digital system.

The effects of digital image enhancement on the detection of vertical root fracture

AIM

To determine the effects of digital image enhancement on observer ability to detect experimentally induced vertical root fractures (VRF).

MATERIAL AND METHODS

A total of 64 extracted human mandibular premolar teeth were used in this study. In 32 teeth, VRFs were created in the bucco-lingual planes by gently tapping with screw-type root-canal pins. The remaining 32 intact teeth served as a control group. Digital images were obtained using a charge coupled device sensor. Three observers separately examined the original and four types of digitally enhanced images (enhanced using sharpness, zoom-in, reverse-contrast, and pseudo-3D functions) at 1-week intervals. All teeth were evaluated using a 5-point scale for the presence/absence of VRF. Evaluations of each image set were repeated 1 month after the initial viewings. Kappa coefficients were calculated to investigate the degree of intra- and inter-observer agreement. The areas under the receiver operating characteristic (ROC) curves (Az values) were calculated using the MedCalc statistical software. ROC values for each image type, observer and viewing were compared using t-tests. A level of alpha = 0.05 was considered significant.

RESULTS

Kappa coefficients for intra-observer agreement ranged from 0.304 to 0.679. Inter-observer agreement kappa values ranged from 0.109 to 0.399 for the first reading and from 0.106 to 0.380 for the second reading. Statistical comparisons between Az values for each observer showed no significant differences (P > 0.05) among image types.

CONCLUSION

There were no differences in diagnostic outcomes among differently enhanced images in the in vitro detection of VRF.

Email for distance diagnosis of oral diseases: a preliminary study of teledentistry

We examined the feasibility of distance diagnosis of oral diseases, using transmission of digital images by email. Twenty-five cases of oral lesions were documented during a 12-month study in a primary care public health clinic in Paraná in Southern Brazil. Clinical electronic charts and images were produced and sent by email to two oral medicine specialists with a median of 10 years experience in the field. The consultants provided a maximum of two clinical hypotheses for each case. In 15 of the 25 cases (60%) both consultants made a correct diagnosis; in seven cases (28%) only one consultant made a correct diagnosis; and in three cases (12%) neither consultant made a correct diagnosis. Thus in 88% of cases, at least one consultant was able to provide the correct diagnosis. The results suggest that distant diagnosis can be an effective alternative in the diagnosis of oral lesions and that the using two distant consultants improves diagnostic accuracy. Primary care public health clinics may benefit from the use of email and digital cameras for telehealth in remote areas where oral medicine specialists are not available.

Comparison of conventional film with different digital and digitally filtered images in the detection of simulated internal resorption cavities--an ex vivo study in human cadaver jaws

OBJECTIVE

To determine observers' ability to detect experimentally induced simulated internal resorption cavities using conventional film, digital images and digitally filtered images.

STUDY DESIGN

In the coronal plane, 11 single-rooted teeth with radiographically visible pulps were split in half. Four artificial internal resorptions were simulated in each tooth at the coronal, cervical, mid-root, and apical locations of the buccal/labial wall. Conventional and digital radiographs were taken from 3 different views in 4 steps. Three observers examined conventional, digital, and digitally filtered images for the presence of resorption cavities. Data were statistically analyzed using analysis of variance. Pair-wise comparison between receptors, location, and size were made by Tukey post hoc test.

RESULTS

One digital system produced a significantly lower proportion of correct readings, with no significant difference between other imaging types (P < .001). In the apical region, internal resorption was the most difficult to detect. The cervical region had the highest proportion of correct readings (P < .001). False-positive readings were higher in the apical and mid-root locations (P < .001). Defect size increased detection ability. Interaction was significant between receptor and size and between size and location (P < .001).

CONCLUSIONS

All systems, except PSP, produced similar results in detecting simulated internal resorption.

Digital and Advanced Imaging in Endodontics: A Review

This review provides an overview of digital radiography as it exists, including advanced imaging such as computed tomography (CT), cone beam volumetric imaging, and micro-CT as relevant to the practice of endodontics. An evidence-based approach to adoption of different imaging technologies is included to assist the practitioner with the selection process of imaging modalities. Commonly used imaging terminology is introduced, as well as the advantages and disadvantages of image processing. New image reconstruction techniques have been introduced that provide information three-dimensionally to the clinician for routine endodontic and surgical treatment planning. The age of three-dimensional imaging and image processing is here. Limitations and advantages of newly introduced imaging modalities are discussed briefly.

Effects of imaging system and exposure on accurate detection of the second mesio-buccal canal in maxillary molar teeth

OBJECTIVES

The objectives of this study were to determine observer ability to detect the second mesio-buccal canal (MB2) in maxillary molars using analog film, CMOS, and photostimulable phosphor x-ray detectors across a wide range of radiation exposures and to determine the optimal exposures for these modalities accurately detecting presence of the MB2.

RESEARCH DESIGN

Using 6 experimental models with 2 maxillary molars in each, images were generated with the 3 detector modalities at nominal x-ray beam angulations of 0 degrees and 10 degrees across a range of radiation exposures. Observers independently assessed presence of the MB2 in images presented in random order. Horizontal root sections were then evaluated to determine true MB2 presence.

RESULTS

For single images at optimal exposures, the correct number of mesiobuccal canals could be identified 55% of the time for CMOS (RVG 6000), 44% of the time for analog x-ray film (InSight), and 39% of the time for photostimulable phosphor (DenOptix). Statistically significant differences were observed between the imaging modalities (chi2 = 23.4, crucial value = 5.99, P < or = .05). RVG 6000 CMOS outperformed both DenOptix photostimulable phosphor (z score = -5.5) and InSight analog direct exposure x-ray film (z score = 4). Exposure affected the rate of accuracy for MB2 detection across the exposure range tested for RVG 6000 and for film, but not to any appreciable degree for DenOptix.

CONCLUSIONS

The CMOS detector (RVG-6000) performed best for evaluating presence of the MB2. This was the only modality to exceed 50% reliability with optimal exposure when single images were considered.

Accuracy of cone beam dental CT, intraoral digital and conventional film radiography for the detection of periapical lesions. An ex vivo study in pig jaws

To compare the accuracy of cone beam CT scanning (NewTom 3G) with intraoral periapical radiography (Dixi2, Planmeca CCD sensor and Insight film) for the detection of periapical bone defects. Ten frozen pig mandibles were used. All soft tissues were removed and the jaws were sagittally sectioned to obtain three blocks from each side of the jaw containing the premolars and the molars with surrounding jaw bone. All teeth with intact roots were then "extracted". First, 15 blocks were used to define defect size and exposure parameters; then, the remaining 45 blocks were divided into three equal groups. In one group, cylindrical defects of 1 x 1 mm were prepared beyond the apices of the extraction sockets, in another group defects of 2 x 2 mm were similarly prepared, while no defects were prepared in the last group. The teeth were replaced into their sockets and digital and conventional radiographs of all blocks were taken under reproducible conditions. In addition, all blocks were CT scanned with the same volumetric data and then reconstructed to provide sagittal and coronal 2-D sections. Masked evaluation of the images (defect present vs no defect) was performed by four calibrated examiners. Statistical analysis was performed with ANOVA and the significance level was set to P < 0.05. NewTom 3G was statistically significantly better in terms of sensitivity (54%), positive (82.6%) and negative (44.5%) predictive values, and diagnostic accuracy (61%) when compared with digital radiographs (23%, 60%, 31%, 39%), and with conventional ones (28%, 70%, 35%, 44%)-except in the positive predictive value. Specificity was similar for all three methods. No difference was observed between the two periapical (digital vs conventional) radiographs. NewTom 3G may be useful in cases of immediate implants intended to replace teeth with suspicion for possible existing endodontic pathology, or in candidate implant sites neighboring such teeth.

In vitro perception of low-contrast features in digital, film, and digitized dental radiographs: a receiver operating characteristic analysis

OBJECTIVE

To compare experimentally the image quality of charged-coupled device (CCD)-based digital, flatbed scanner digitized, and dental film radiographs.

STUDY DESIGN

High-contrast standardized radiographs of an aluminum step wedge containing boreholes were obtained on dental radiographic film (F) and a CCD receptor (D). Digitization (S) was done with a flatbed scanner. Each radiograph was separated into 23 single images, 18 of which showed a dark spot. Thirty observers indicated their confidence on the visibility of the spots for a receiver operating characteristic (ROC) analysis.

RESULTS

Mean Az values (area beneath the ROC curves) differed significantly (P < .05), being highest for D (Az = 0.76), followed by F (Az = 0.71) and S (Az = 0.60). Mean sensitivity of S (0.45) was significantly (P = .000) lower than for D (0.66) and F (0.67).

CONCLUSION

The difference between modality D and F was small. However, the inferior performance of S images, particularly in dark regions, could be clinically relevant.

Evaluation of digital optical density of bone repair in rats medicated with ketoprofen

The purpose of this study was to evaluate the influence of ketoprofen on bone repair process in tibiae of rats by means of analysis of the digital optical density. Twenty Wistar rats were assigned to two groups: an untreated control group and a group treated with ketoprofen. The experimental procedures comprised the following stages: general anesthesia, preparation of a unicortical bone defect on the left tibia of each rat, medication with ketoprofen and radiographic examination. Digital radiographic images were acquired using Visualix GX-S-HDI digital sensor and an x-ray equipment. Radiographs were taken at baseline, 7, 14, 21 and 30 days postoperatively and the optical density (OD) was evaluated using the Vix win 1.4 system. The mean values of OD readings were analyzed statistically by ANOVA and Tukey's test with significance level set at á=5%. The control group showed a statistically significant correlation (p=0.001) between time and optical density, while the ketoprofen group exhibited a weak and not statistically significant correlation (p=0.100). The control group presented the smallest OD ratios at days 1 and 7, and the greatest OD ratios at days 14, 21 and 30, with statistically significant difference (p=0.001). There was no significant differences (p=0.100) among the OD ratios in the ketoprofen group, regardless of the evaluation period. The findings of this study suggest that ketoprofen influenced bone repair process because there was an increase in optical density during the first week and delayed new bone formation after the 21st day.

Clarity and diagnostic quality of digitized conventional intraoral radiographs

OBJECTIVES

To compare digital images of conventional radiographs with the original radiographs for perceived clarity of endodontic files, periapical lesions and carious lesions, and to establish the diagnostic value of the digital images.

METHODS

Four groups of ten radiographs were used: standardized bitewings demonstrating carious lesions, periapical radiographs of apical lesions, periapical radiographs showing endodontic files of various sizes at working length, and standardized periapical radiographs with size 08 files at working length. Radiographs were photographed using an Olympus C 2500-L digital camera and a Nikon D1X digital camera and were scanned using a Nikon Supercoolscan 4000 ED film/slide scanner. The digital images were then transferred to a Toshiba Satellite 2210 laptop. Three general dental practitioners compared each conventional radiograph with the three matching digital images. Images were ranked for clarity and were assessed for diagnostic quality. Data were analysed using General Estimating Equations.

RESULTS

The clarity and diagnostic quality of the conventional radiographs were superior to the digital images produced by the three techniques (P < 0.001). No significant difference was found between the Nikon D1X and Camedia 2500-L cameras for clarity or diagnostic quality. The scanner was equivalent to the Camedia 2500-L camera for diagnostic quality, but was otherwise inferior to both cameras.

CONCLUSIONS

Digitizing conventional radiographs using current high-grade digital cameras or scanners does not produce images of diagnostic quality. Improved resolution of viewing monitors is necessary to fully harness the potential of digital technology.

Indirect digital images: limit of image compression for diagnosis in endodontics

AIM

To analyse the impact of the loss of information that results from the compression of a file containing a radiographic image.

METHODOLOGY

Fourteen intraoral radiographs were digitized employing an AGFA ARCUS II scanner at an optical resolution of 300 ppi and with a grey scale of 8 bytes. The images were stored in Tagged Image File Format (TIFF). The files were compressed with no information loss with the WinZip 8.0 program. Compression with information loss was performed using the Photoshop 5.0 program (Adobe Systems Inc., San José, CA. USA) and the Joint Photograph Expert (Group (JPEG) format. Each of the images was compressed to one of the 11 qualities available (10-0). An expert performed the qualitative analysis. The quantitative analysis involved digital subtraction with each of the JPEG images to yield a new image using Photoshop 5.). The histograms of grey values were submitted to statistical analysis. The mean and standard deviation were calculated for each image.

RESULTS

The data revealed that a JPEG lossy compression, six times smaller than the original TIFF, is compatible with diagnostic applications.

CONCLUSIONS

The compression ratio calculated as the quotient between the file sizes and the standard deviation of the values corresponding to the image that resulted from digital subtraction may be employed to assess the outcome of the compression process and guarantee adequate quality.

Are photographic records reliable for orthodontic screening?

AIM

The aim of the study was to evaluate the reliability of a panel of orthodontists for accepting new patient referrals based on clinical photographs.

SAMPLE

Eight orthodontists from Greater Manchester, Lancashire, Chester, and Derbyshire observed clinical photographs of 40 consecutive new patients attending the orthodontic department, Hope Hospital, Salford.

METHOD

They recorded whether or not they would accept the patient, as a new patient referral, in their department. Each consultant was asked to take into account factors, such as oral hygiene, dental development, and severity of the malocclusion.

STATISTICS

Kappa statistic for multiple-rater agreement and kappa statistic for intra-observer reliability were calculated.

RESULTS

Inter-observer panel agreement for accepting new patient referrals based on photographic information was low (multiple rater kappa score 0.37). Intra-examiner agreement was better (kappa range 0.34-0.90).

CONCLUSION

Clinician agreement for screening and accepting orthodontic referrals based on clinical photographs is comparable to that previously reported for other clinical decision making.

Impact of lossy compression on diagnostic accuracy of radiographs for periapical lesions

OBJECTIVES

The purpose of this study was to evaluate the lossy Joint Photographic Experts Group compression for endodontic pretreatment digital radiographs.

STUDY DESIGN

Fifty clinical charge-coupled device-based, digital radiographs depicting periapical areas were selected. Each image was compressed at 2, 4, 8, 16, 32, 48, and 64 compression ratios. One root per image was marked for examination. Images were randomized and viewed by four clinical observers under standardized viewing conditions. Each observer read the image set three times, with at least two weeks between each reading. Three pre-selected sites per image (mesial, distal, apical) were scored on a five-scale score confidence scale. A panel of three examiners scored the uncompressed images, with a consensus score for each site. The consensus score was used as the baseline for assessing the impact of lossy compression on the diagnostic values of images. The mean absolute error between consensus and observer scores was computed for each observer, site, and reading session.

RESULTS

Balanced one-way analysis of variance for all observers indicated that for compression ratios 48 and 64, there was significant difference between mean absolute error of uncompressed and compressed images (P <.05). After converting the five-scale score to two-level diagnostic values, the diagnostic accuracy was strongly correlated (R (2) = 0.91) with the compression ratio.

CONCLUSION

The results of this study suggest that high compression ratios can have a severe impact on the diagnostic quality of the digital radiographs for detection of periapical lesions.

Accuracy of diagnosis of fractures by maxillofacial and accident and emergency doctors using plain radiography compared with a telemedicine system: a prospective study

Ten facial radiographs with fractures and 10 without fractures were viewed by eight oral and maxillofacial surgery (OMFS) and eight accident and emergency (A&E) doctors who were each asked questions about the presence and site of any fractures as well as the quality of the images and diagnostic confidence. Each radiograph was then transmitted over a teleradiology link and viewed by the same OMFS doctors who answered the same questions. The position of the fracture was more accurately assessed using plain radiography. Diagnosis by OMFS doctors using telemedicine was broadly comparable with fracture diagnosis by A&E doctors using plain radiography. Poor quality radiographs and frontozygomatic and infraorbital rim fractures were poorly diagnosed by telemedicine. This telemedicine system was a useful tool to aid diagnosis of most facial fractures. The need for appropriate clinical information is vital. Diagnosis of frontozygomatic and infraorbital rim disruption using telemedicine is less reliable than plain radiography.

[Clinical and comparative study of the image quality of 3 digital radiographic systems, E-speed film and digitalized film]]

The aim of this study was to evaluate, subjectively, the image quality of two CCD digital systems, a digital storage phosphor system, a digitized film and an E-speed film. Five objects were radiographed with 50, 60 and 70 kVp, with exposure times of 0.08, 0.13, 0.2, 0.4 and 0.8 s. In order to maximize the fidelity of the results, the dental X-ray unit employed was submitted to an evaluation so that the relation between exposure time and dose could be established. A good reproducibility was obtained. Six evaluators analyzed 375 images, using a scoring scale which ranged from 0 to 4. The results revealed different responses, indicating that the storage phosphor system had the best performance, in the various exposures employed. However, it was possible to conclude that all systems studied, except for the Sens-A-Ray, can offer images in ideal conditions for the diagnosis, as long as their latitudes are respected.

A comparative evaluation of the diagnostic efficacy of film and digital sensors for detection of simulated periapical lesions

OBJECTIVE

The purpose of this study was to evaluate the diagnostic efficacy of Ektaspeed Plus film (EPF), a charge-coupled device (CCD), and photostimulable phosphor (PSP)-based digital images for detection of simulated periapical lesions.

STUDY DESIGN

Lesions were simulated in the periapical areas of 24 human mandibular sections invested in acrylic using burs of sizes #1, 2, 4, and 6 and imaged using EPF, CCD, and PSP sensors. Percent correct response scores, sensitivity, and specificity values were computed for all variables. Repeated-measures analysis of variance and post hoc testing were performed to determine the effects of imaging modality, observer, and lesion sizes with respect to lesion detection.

RESULTS

EPF displayed the highest sensitivity and specificity, followed by PSP and CCD images (P <.001). Percent correct score was the highest for 3 of 4 observers when EPF was used. Analysis of variance revealed significance (P <.001) with respect to all variables. Observers with experience in digital image-viewing performed better than those without such experience (P <.001). Intraobserver agreement was fair (kappa = 0.5).

CONCLUSIONS

EPF outperformed CCD and PSP images when observers could manipulate image characteristics.

Comparison of diagnostic accuracy of digital imaging by using CCD and CMOS-APS sensors with E-speed film in the detection of periapical bony lesions

OBJECTIVE

The purpose of this study was to compare E-speed Plus film and digital imaging with a charge-coupled device (CCD) sensor and a complementary metal-oxide semiconductor active pixel sensor (CMOS-APS) in the detection of periapical bone lesions.

STUDY DESIGN

Periapical lesions were created in the cortical and trabecular bone of 10 dried human mandibles. Seventy radio-graphic images and 140 digital images were evaluated by 6 endodontists and 2 radiologists. Receiver operating characteristics curves and analysis of variance were used for statistical analysis.Results. No statistically significant differences were found between film, CCD, and CMOS-APS systems. Lesion detection occurred with significantly greater accuracy in cortical bone than in trabecular bone, as well as when the cortical plate was involved.

CONCLUSIONS

That no differences were found between the two sensors lends support for the use of CMOS-APS sensors, which require less system power and may have longer life spans than CCD sensors. Digital imaging required 50% less radiation than film to obtain the same diagnostic information.

Interpretation of artificial and in vivo periapical bone lesions comparing conventional viewing versus a video conferencing system

The purpose of this study was to compare the interpretation of conventional radiographs transmitted by a video teleconferencing system to conventional viewbox interpretation for both artificial and in vivo periapical bone lesions. A total of 30 radiographic images were used in this study: 20 radiographic images of artificial lesions and 10 radiographs from actual patients. Two endodontists evaluated the 30 images by giving a "yes" or "no" response when determining whether a periapical lesion was present on the radiograph. The study was conducted in two sessions, separated by a 6-wk interval to minimize evaluator recall. Results of the study revealed no statistical difference between the ability of the evaluator to identify periapical bone lesions using conventional radiographs on a viewbox and his ability to interpret the same images transmitted on a monitor screen.

Potential for fraudulent use of digital radiography

BACKGROUND

Digital radiographic images can be manipulated using personal computers. To test the potential for fraudulent use, the authors altered a series of dental radiographs, printed them to simulate duplicated films and submitted them for authorization of proposed treatment.

MATERIALS AND METHODS

The authors obtained periapical radiographs of teeth that contained small restorations or were unrestored from the files of three dental patients at a private dental practice. The authors used a flatbed scanner to digitize and import the radiographs into a computer. Then they added dental caries, large restorations, fractures and periapical pathosis to the radiographs. The authors proposed to the insurance companies that the teeth in question be restored using expensive treatment, such as root-canal therapy and full-coverage crowns.

RESULTS

In each case, the insurance companies authorized the proposed treatment based on the appearance of the teeth on the radiographs. The altered images illustrated an apparent need for dental treatment that was not required and that could have led to payment for treatment that was not actually performed.

CONCLUSIONS

This study illustrates the potential for the fraudulent use of manipulated digital radiographic images.

CLINICAL IMPLICATIONS

Dentistry should be aware of the implications of the potential for such abuse and should develop measures both to prevent it from occurring and to facilitate its detection.

Radiographic study of the maxillary canine tooth of four mesaticephalic cats

The radiopaque and radiolucent anatomical structures that are superimposed over the root of the maxillary canine tooth in mesaticephalic cats were identified on digital radiographs made at various angles. The vomer bone, the nasal bone, the palatine fissure, and the infraorbital foramen were not superimposed over the root of the canine tooth in the range of angles examined. Superimposition with the palatine sulcus (which is rarely visible clinically because of silhouetting of the soft tissues) only occurred at extreme horizontal (cross-sectional arc) angles. The second premolar tooth was superimposed at a cross-sectional angle of 80 degrees and 90 degrees. The structures of concern in the interpretation of radiographs of the maxillary canine tooth in mesaticephalic cats are the conchal crest, the line of conjunction between the vertical body of the maxilla and its palatine process, the incisivomaxillary canal (which is rarely visible on radiographic images), and the lachrymal canal. Because of their anatomical vicinity, the radiographic position of these structures relative to the maxillary canine tooth can only be minimally changed. It was not possible to identify an "ideal" angle to radiograph the maxillary canine tooth in these four mesaticephalic cats. However, an acceptable compromise between minimal distortion of the image and satisfactory visualization of the root was obtained with the radiographic beam (rostro-caudal rotation) angled at 80 degrees and the skull (rotation in cross-sectional arc) angled at 70 degrees.