Increasing clinical relevance in oral radiology: Benefits and challenges when implementing digital assessment.

AIMS: The aims of the study were to investigate benefits and challenges in implementing a digital examination and study the clinical relevance of the digital examination in relation to clinical training and practice. MATERIAL AND METHOD: The study was based on semi-structured focus-group interviews from two distinct student populations (2016 and 2017) in a bachelor programme in dental hygiene. In addition, conversational data from a plenary discussion from the whole second student population (2017) were collected and analysed. The data were approached on basis of content analysis. RESULTS: A benefit experienced in the digital examination was the ease in typing and editing answers on the computer. This suggests an increased effectiveness in computer-based compared to analogue examinations. An additional advantage was the experienced relevance of the examination related to the clinic. This finding refers not only to the digital presentations of images, but also to the entire setting in the clinic and dental practice. The limitations reported by the students were non-optimal viewing conditions for presenting radiographic images and difficulties in obtaining an overview of the assignments compared to paper-based examinations due to the linear digital examination format. The last finding on lacking overview revealed an influence on student performances which should be taken seriously in designing digital examinations. CONCLUSION: In conclusion, the digital layout increases efficiency and clinical relevance of examinations to a certain extent. Obstacles were found in limitations related to image presentation and lack of overview of the examination. The latter challenge raises questions related to developing suitable assessment software.

Faculty development for clinical teachers in dental education.

UNLABELLED: Dental education has been reviewed, and suggestions for further enhancement include the implementation of faculty development activities to enhance teaching and learning environments. PURPOSE: The aim of this study was to gain insight into the participants' perceptions of outcomes of faculty development for clinical teachers and clinical learning environments as well as into the sustainability of such outcomes. METHODS: The program was organized in the form of (i) a 2-day seminar; (ii) collegial supervision and development projects; and (iii) a 1-day follow-up seminar. The participants' perceptions from the five-first programs were studied. A Web-based questionnaire was sent to all participants, that is 3-27 months after completion of the program (follow-up survey). RESULTS: The outcomes of the program (response rate 70%) indicate a strong impact of the program on the clinical teachers' competence and on the clinical learning environments. The teachers report that they think more about what their students really learn, have become more conscious about how they supervise and have been stimulated to become better teachers. The learning environment as well as collaboration, and calibration between teachers have improved. The novice teachers report greater benefits than do the experienced teachers. The participants initiated a variety of development projects during the program. The majority of the participants continued the development activities. CONCLUSIONS: The faculty development program presented confirms that faculty development activities for clinical teachers based on theories of learning and experiences documented in the literature can be implemented with positive outcomes for individual teachers and for the learning environments.

Osteoarthritis of the temporomandibular joint: an evaluation of the effects and complications of corticosteroid injection compared with injection with sodium hyaluronate.

The purpose of this study was to compare the efficacy and the complications of intra-articular temporomandibular joint (TMJ) injections in 40 patients with osteoarthritis of the TMJ. The subjects were randomly divided into two groups, and the patients received either two intra-articular injections with sodium hyaluronate or two intra-articular injections with corticosteroids, 14 days apart. The effect of the treatment was evaluated 14 days, 1 and 6 months after the initial injection and was based on the following measurements: pain intensity, pain localization, joint sounds, mandibular function and complications. Both groups of patients had less pain intensity at the 6-month follow-up, and there was significantly less pain intensity in the group of patients receiving sodium hyaluronate compared with corticosteroids (P = 0.001). A decrease in crepitation was seen in both groups. In the 20 subjects receiving sodium hyaluronate both the mandibular vertical opening and protrusion increased significantly (P < 0.000). Lateral movement from the affected side increased both in subjects injected with sodium hyaluronate (P = 0.024), and those injected with corticosteroids (P = 0.042). In conclusion, this study confirms that injections in the TMJ with sodium hyaluronate or corticosteroids may reduce pain and improve function in patients with osteoarthritis. The injections were more effective in patients with only TMJ pain compared with patients suffering from both TMJ and myofascial pain. Injection with sodium hyaluronate was significantly more effective in decreasing pain intensity than corticosteroids. Temporary pain after injections may be observed.

Sliding window adaptive histogram equalization of intraoral radiographs: effect on image quality.

OBJECTIVES: To investigate whether contrast enhancement by non-interactive, sliding window adaptive histogram equalization (SWAHE) can enhance the image quality of intraoral radiographs in the dental clinic. METHODS: Three dentists read 22 periapical and 12 bitewing storage phosphor (SP) radiographs. For the periapical readings they graded the quality of the examination with regard to visually locating the root apex. For the bitewing readings they registered all occurrences of approximal caries on a confidence scale. Each reading was first done on an unprocessed radiograph ("single-view"), and then re-done with the image processed with SWAHE displayed beside the unprocessed version ("twin-view"). The processing parameters for SWAHE were the same for all the images. RESULTS: For the periapical examinations, twin-view was judged to raise the image quality for 52% of those cases where the single-view quality was below the maximum. For the bitewing radiographs, there was a change of caries classification (both positive and negative) with twin-view in 19% of the cases, but with only a 3% net increase in the total number of caries registrations. For both examinations interobserver variance was unaffected. CONCLUSIONS: Non-interactive SWAHE applied to dental SP radiographs produces a supplemental contrast enhanced image which in twin-view reading improves the image quality of periapical examinations. SWAHE also affects caries diagnosis of bitewing images, and further study using a gold standard is warranted.

Comparison of standard and task-specific enhancement of Digora storage phosphor images for approximal caries diagnosis.

OBJECTIVES: To compare approximal caries detection on Digora storage phosphor images pre-enhanced with the automatic "caries-specific Oslo enhancement procedure" ("Oslo-enhanced" method) and storage phosphor images individually enhanced by observers particularly experienced in digital imaging using standard brightness and contrast functions of the Digora system ("Digora-enhanced" method). METHODS: Seven staff members from four oral radiology departments rated 240 approximal surfaces for caries with regard to lesion depth in the inner and outer half of the enamel and dentine, using a 5-point confidence scale. The observations were validated histologically. A receiver operating characteristic (ROC) analysis and an analysis of variance with three dependent variables (observer confidence, observer signed error and observer absolute error) were performed. RESULTS: The most evident difference between the methods as elucidated by the ROC analysis was the highly significant smaller interobserver and intraobserver variance with the Oslo-enhanced method for all but one observer. The methods were not different with regard to average diagnostic accuracy (A(z) values) as tested with paired t-tests, and there was no correlation between A(z) across methods. The method and lesion main effects, as well as the lesion by method interaction effect, were multivariately significant (P<0.001) in favour of the Oslo-enhanced method. On a univariate level, the method main effect was not significant for the absolute observer error (P=0.330). All other univariate effects were significant (P<0.001). CONCLUSIONS: The accuracy of approximal caries detection with Digora storage phosphor images pre-enhanced and images individually enhanced was similar, but interobserver and intraobserver variability improved with the Oslo-enhanced method. Since image manipulation is not performed with the Oslo-enhanced method, the increased speed of the diagnostic procedure combined with the improved observer variability would probably be even more pronounced for the general dental practitioner.

Decision criteria and characteristics of Norwegian general dental practitioners selecting digital radiography.

OBJECTIVES: To evaluate Norwegian general dental practitioners' decision criteria and characteristics for choosing digital radiographic equipment. METHODS: A questionnaire was sent to all dental practitioners in Norway (n = 3940). They were categorised on the basis of their responses as either a 'digital radiography' (DR) or 'non-digital radiography' (non-DR) dentist. Demographic, clinical, and electronic technology variables were recorded. Dentists ranked on a six-point scale their reasons for choosing or not choosing digital radiography. Their responses were analysed by logistic regression. RESULTS: Two thousand, one hundred and ninety-nine dentists (56%) replied. Three hundred and nine (14%), (219 men, 86 women and four not stated) had chosen to use digital radiography. The logistic regression analysis revealed that gender, age and years in dentistry were not significant factors in determining their decision, whereas working in a private or group practice was. The number of computers in the practice was the most important of the electronic technology variables. The non-DR dentists strongly agreed that 'digital radiography is too expensive' and were 'satisfied with film'. The DR dentists strongly agreed that the 'use of chemicals can be avoided', 'patient dose is reduced', and 'archiving is facilitated'. CONCLUSION: Working in a private or group practice or using multiple computers were significant factors in choosing digital radiography.

Experience of Norwegian general dental practitioners with solid state and storage phosphor detectors.

OBJECTIVES: To evaluate the opinions of Norwegian dental practitioners regarding the use of solid state sensor and storage phosphor (SP) detectors for intra-oral radiography. METHODS: A questionnaire received from 2199 dentists 309 (219 male, 86 female, four unknown) confirmed the use of digital radiography in their practices. RESULTS: Sixty-one per cent of dentists used a SP and 35% a sensor system; four (1.3%) used both. Approximately 50% of dentists had experienced technical problems and 33% had needed repairs. Almost all dentists stored their images on the hard disk (>97%) and 81% made a daily back-up. More sensor than SP users found difficulty with the positioning holder. Two-thirds of dentists reported digital image quality was the same or better than film. More Digora (Soredex, Helsinki, Finland) users reported better image quality than Denoptix (Gendex, Milan, Italy) or Digident (Digident, Nesher, Israel) users. Mean reduction in exposure time was 55% (range 2-90%), although 17 dentists stated that no reduction was achieved. Approximately half of the sensor users also used film and 38% of the SP users. Film was used more often for bitewing examination by the sensor users (27%) than by the SP users (4%). Mean time saved by the sensor users was 36 min/day (range 10-120) and by the SP users 25 min/day (range 5-120). CONCLUSIONS: The majority of dentists felt that digital image quality was the same or better than film and exposure and examination times were reduced. However, technical problems and repairs were common.

Approximal caries depth assessment with storage phosphor versus film radiography. Evaluation of the caries-specific Oslo enhancement procedure.

OBJECTIVES: To study whether caries-specific enhancement of storage phosphor images might improve the observer performance of approximal caries depth assessments compared with film radiography. MATERIALS AND METHODS: 120 exposures were made of 120 extracted human teeth. To obtain geometrically identical images, Ektaspeed Plus films and storage phosphor plates were exposed simultaneously. The imaging plates were scanned in a Digora scanner and the files transferred to a different platform for image enhancement. Nine observers viewed films and storage phosphor images without provisions for adjustment of image intensity and contrast. For each imaging modality, 240 approximal surfaces were rated for caries on a 5-point confidence scale. Definite and probable caries lesions were also rated for lesion depth, and all ratings were compared with the histological state. Diagnostic accuracy was expressed as the area under the ROC curve (A(z) value). Paired t tests were used to compare the imaging modalities for diagnostic accuracy and F tests to compare observer variances. RESULTS: Enhanced storage phosphor images demonstrated significantly higher mean A(z) values than film (p = 0.0066). Significantly higher mean A(z) values were demonstrated in the outer half of enamel (p = 0.01), but no significant differences were found between the modalities for caries lesions penetrating beyond the outer half of the enamel. The number of correctly diagnosed true-positive surfaces with caries in outer enamel was significantly higher with storage phosphor images than with film (p = 0.00014). False-positive surfaces were most frequently registered in the outer enamel with both modalities, but in this region the number of false-positive surfaces was significantly higher with storage phosphor images than with film (p = 0.0038). Pooled sensitivity and specificity values were 0.48/0.94 and 0.61/0.86 for film and storage phosphor images, respectively. The interobserver variability was significantly lower for storage phosphor images than for film. CONCLUSION: Enhancement of storage phosphor images with a caries-specific procedure significantly improved the accuracy of caries depth assessments in the outer half of the enamel compared with film radiography and reduced observer variability.

Detection of approximal caries with a storage phosphor system. A comparison of enhanced digital images with dental X-ray film.

OBJECTIVES: To compare the accuracy of approximal caries detection using enhanced and unenhanced storage phosphor images and dental X-ray film. METHODS: Fifty premolar/molar teeth were exposed simultaneously under standardized conditions on storage phosphor (SP) image plates (Digora) and Ektaspeed film. The image files were transferred to a different platform for image processing. Using a five-point confidence scale, ten observers rated 95 approximal surfaces for caries in enamel and dentin with three image modalities: enhanced and unenhanced SP images and film. The observations were validated microscopically. Diagnostic accuracy was measured as the area beneath the ROC curve (Az). RESULTS: Enhanced SP images had significantly higher Az values in both enamel (Az = 0.819) and dentin (Az = 0.845) than unenhanced images and film. No significant differences were found in either enamel or dentin between unenhanced SP images (Az = 0.780 and Az = 0.789) and film (Az = 0.688 and Az = 0.793). CONCLUSION: Enhancement of storage phosphor images improved detection of approximal caries in this in vitro study compared with unenhanced images and Ektaspeed film.

Intraoral storage phosphor radiography for approximal caries detection and effect of image magnification: comparison with conventional radiography.

OBJECTIVES: The aim of this study was first to test the newly developed storage phosphor (SP) system Digora for diagnostic accuracy of approximal caries detection with special emphasis on image magnification compared with conventional radiography, and second, to test whether the image surroundings could have an influence on observer performance. DESIGN: SP plates and Ektaspeed films were exposed simultaneously to 50 extracted premolars/molars, and the SP image files were transported to a different platform for processing. Ten observers rated 95 approximal surfaces for caries with four imaging modalities: (1) SP images at dental film size viewed with black surroundings, (2) magnified (x4) images viewed in the same manner, (3) magnified (x4) images viewed with text and graphics framing, and (4) films viewed on a light box. The observations were validated with microscopy. Diagnostic accuracy was calculated as the area beneath the receiver operating characteristic curve (AZ). RESULTS: No significant differences were found between SP images and films. Magnified SP images with text and graphics demonstrated significantly higher AZ values than nonmagnified images both for enamel and dentin, and magnified images with black surroundings demonstrated similar results for dentin. CONCLUSIONS: In this in vitro material the observer performance for approximal caries detection with SP images was comparable to that with Ektaspeed films. The magnified SP images generally showed a significantly higher diagnostic accuracy than the nonmagnified SP images.

Effect of image magnification of digitized bitewing radiographs on approximal caries detection: an in vitro study.

OBJECTIVE: To evaluate whether or not image magnification of digitized bitewing radiographs had an effect on approximal caries detection. METHODS: Twenty general dental practitioners (GDPs) rated a total of 140 digital images (28 approximal surfaces at five different magnifications, x3, x6, x12, x18 and x30) for caries on a 5-point confidence scale. The observations were compared with the state of the approximal surfaces on visual inspection. For each GDP the average response rate was calculated. Paired t-tests were used to compare the diagnostic response at the five different image magnifications. RESULTS: The mean response rates obtained at x18 and x30 magnifications were significantly inferior to those at the three smaller magnifications (p < 0.007). CONCLUSION: Digital image magnification has a significant influence on observer performance in the detection of approximal caries, with an upper limit beyond which diagnostic accuracy may be reduced. Further research is needed to determine limits for various different diagnostic tasks so as to give GDPs guidelines on the appropriate magnifications to use.

The effect of cathode ray tube display format on observer performance in dental digitized radiography: comparison with plain films.

Studies of observer performance with non-manipulated digital images are almost lacking; nor has the effect of cathode ray tube (CRT) display formats been evaluated. The present study compared the diagnostic accuracy of observers with and without clinical experience in evaluating intra-oral dental films and the corresponding non-manipulated digitized images. Three different-sized (5", 9", 17") monitors were used to study the effect of CRT display format. Artificial radiolucent and radiopaque lesions in dry human mandibles were examined. ROC curve areas were averaged and cross-tabulated according to viewing method and observer experience. For the total group, the non-manipulated digital images resulted in smaller ROC curve areas than the plain films for all CRT formats, with a significantly inferior result for the 17" images (p = 0.036). The increase in diagnostic accuracy of the digital images with decreasing CRT size was not significant (p > 0.05). There was some difference in the mean ROC curve areas between teachers and students, but the effect of the viewing methods was not significant. In terms of observer performance, the experienced observers demonstrated a reduced, and the inexperienced an increased, variability with the digital images compared with conventional film.

Personal computer equipment for dental digital subtraction radiography vs. industrial computer equipment and conventional radiography.

A "low-cost" personal computer (PC) system used to digitize dental radiographs was tested by assessing the accuracy of its subtraction images versus those of "high-cost" industrial equipment and conventional radiography. Subtraction images were made of artificial lesions in human femur bone and subsequently evaluated by students and teachers. The observations were analyzed in terms of true positive and false positive reports. "Low-cost" and "high-cost" subtraction images revealed only small differences in diagnostic accuracy. Compared to conventional radiography, the diagnostic accuracy of the subtraction images with the "low-cost" PC system was significantly higher for all observers. The interexaminer variance was similar for the subtraction and the conventional images for both students and teachers, except for a significantly reduced interexaminer variance for the teachers concerning the true positive reports with the "low-cost" PC subtraction technique.

Transcutaneous nerve stimulation in a group of patients with rheumatic disease involving the temporomandibular joint.

The effect of transcutaneous nerve stimulation (TNS) was evaluated and compared with placebo TNS in 19 patients (17 women, mean age 33 years) with orofacial functional pain and rheumatic disease involving the temporomandibular joint. In two double-blind noncrossover experiments, high frequency TNS (100 Hz) and low frequency TNS (2 Hz) were evaluated by comparison of the patients' functional and rest pain, muscle and joint tenderness, and jaw function. A significant treatment effect was obtained for all treatment methods regarding functional and rest pain and muscle and joint tenderness. None of the parameters except functional pain, which improved significantly more after high frequency TNS than placebo TNS, revealed any difference between the methods. Jaw function, however, revealed a few differences between high frequency TNS and placebo TNS.

Reproducibility and overlapping of bitewing radiographs: comparison of Eggen-bite with Kwik-bite.

In the present study the reproducibility of horizontal dimensions and of overlappings of two filmholder techniques with aiming devices (Eggen-bite and Kwik-bite) and additionally the number of overlappings on the resulting bitewing radiographs were compared. The overlapping reproducibility was significantly higher with Kwik-bite. The microdensitometric reproducibility demonstrated the same tendency, but the result was not significant. Bitewings carried out by an oral radiologist demonstrated fewer overlappings with Eggen-bite than with Kwik-bite, while bitewings carried out by inexperienced students revealed no difference between the methods. Both reproducibility and number of overlappings should be taken into consideration when bitewing filmholder techniques are used in epidemiological and longitudinal studies.