Performance of a commercially available Generative Pre-trained Transformer (GPT) in describing radiolucent lesions in panoramic radiographs and establishing differential diagnoses.

OBJECTIVES: To evaluate the performance of a commercially available Generative Pre-trained Transformer (GPT) in describing and establishing differential diagnoses for radiolucent lesions in panoramic radiographs. MATERIALS AND METHODS: Twenty-eight panoramic radiographs, each containing a single radiolucent lesion, were evaluated in consensus by three examiners and a commercially available ChatGPT-3.5 model. They provided descriptions regarding internal structure (radiodensity, loculation), periphery (margin type, cortication), shape, location (bone, side, region, teeth/structures), and effects on adjacent structures (effect, adjacent structure). Diagnostic impressions related to origin, behavior, and nature were also provided. The GPT program was additionally prompted to provide differential diagnoses. Keywords used by the GPT program were compared to those used by the examiners and scored as 0 (incorrect), 0.5 (partially correct), or 1 (correct). Mean score values and standard deviation were calculated for each description. Performance in establishing differential diagnoses was assessed using Rank-1, -2, and - 3. RESULTS: Descriptions of margination, affected bone, and origin received the highest scores: 0.93, 0.93, and 0.87, respectively. Shape, region, teeth/structures, effect, affected region, and nature received considerably lower scores ranging from 0.22 to 0.50. Rank-1, -2, and - 3 demonstrated accuracy in 25%, 57.14%, and 67.85% of cases, respectively. CONCLUSION: The performance of the GPT program in describing and providing differential diagnoses for radiolucent lesions in panoramic radiographs is variable and at this stage limited in its use for clinical application. CLINICAL RELEVANCE: Understanding the potential role of GPT systems as an auxiliary tool in image interpretation is imperative to validate their clinical applicability.

Effect of metal artefact reduction level on the assessment of dental implant positioning by cone-beam computed tomography.

OBJECTIVES: This study evaluated the effect of metal artefact reduction (MAR) level and tube current on the assessment of dental implant positioning relative to the mandibular canal (MC) through cone-beam computed tomography (CBCT). METHODS: Titanium dental implants were placed in dried mandibles at 0.5-mm superior to the MC (group 1/n = 8) and 0.5-mm inside the MC with perforation of the cortex (group 2/n = 10). CBCT scans were obtained with different levels of MAR (off, medium, and high) and 2 tube currents (4 and 8 mA). Four examiners analysed the images and scored the contact between the implant and the MC using a 5-point scale. Sensitivity, specificity, area under receiver operating characteristic curve (ROC), and frequency of scores were calculated. Data were compared with analysis of variance 2-way and Tukey's test and scores with Chi-square test. RESULTS: Specificity and area under ROC curve decreased significantly when MAR level was high compared with MAR-medium and MAR-off. The frequency of score 3 (inconclusive) was the highest, and scores 1 and 5 (definitely no contact and definitely contact, respectively) were the lowest with MAR-high, regardless of the tube current. When MAR was off, there were higher frequencies of scores 1 and 5. CONCLUSIONS: The level of MAR influences the assessment of the relationship between the dental implant and the MC. MAR-high led to lower diagnostic accuracy compared with MAR-medium and off. ADVANCES IN KNOWLEDGE: This article shows that high level of MAR can interfere in the diagnostic of dental implant positioning relative to the MC, decreasing its accuracy.

Variations in head tilt during the acquisition of CBCT scans and their effects on effective radiation dose.

OBJECTIVES: This study evaluated the impact of variations in anteroposterior and lateral tilts of patients' head on radiation-weighted doses to organs/tissues and effective doses using three different cone beam computed tomography machines. METHODS: An anthropomorphic phantom was used to estimate radiation doses in three CBCT machines (OP300, Eagle X 3D, and Eagle Edge). Thermoluminescent dosimeters were placed in regions corresponding to pre-stablished organ/tissues. CBCT examinations from the posterior mandible and anterior maxilla regions were acquired, with three different anteroposterior angulations (0°, 30°, and 45°), and from the posterior mandible in three different lateral angulations (0°, 20° to the left, and 20° to the right side). Radiation-weighted doses for each organ/tissue and effective doses were calculated for each machine and angulation. RESULTS: For the posterior mandible acquisitions, anteroposterior angulations of the head at 30° and 45° yielded a reduction in effective doses in all three devices. A 20° tilt to the right side resulted in lower doses than to the left (same side as the FOV). For the anterior maxilla, increased anteroposterior angulation was associated with reduction in effective dose in two devices. CONCLUSION: Effective doses are lower when small FOV CBCT exams of the posterior mandible and anterior maxilla are acquired with increased anteroposterior head angulation at 30° and 45°. For FOV in the posterior mandible, a 20° lateral tilt towards the side opposite to the FOV also yields lower effective doses. The main contribution to these dose reductions is the decrease in dose to salivary glands.

Radiographic perception of anatomical structures and bony changes in oncologic patients under antiresorptive therapy.

PURPOSE: To assess radiographic presentation of anatomical structures, bony changes and soft tissue calcifications on panoramic radiographs of oncologic patients under high dose antiresorptive drug therapy (ART) before exposure to dental extraction. METHODS: Panoramic radiographs of 57 patients under ART, taken previously to tooth extraction, and 57 control patients were evaluated by two oral radiologists regarding bone pattern, anatomical structures visibility, estimation of cortical width, mandibular cortical index (MCI), and presence of soft tissue calcifications. Parameters were compared between ART and age- and gender-matched healthy control groups. Bone patterns were further assessed by regions with or without tooth extractions and according to uneventful healing or MRONJ development. All comparisons were made using chi-square test with significance level set at 5%. RESULTS: Mandible and posterior maxilla presented more sclerotic bone patterns in patients under ART, regardless of tooth extraction and MRONJ development status (p < 0.05). Heterogeneous bone pattern was identified in two regions that both were subsequently affected by MRONJ. Anatomical structure visibility and presence of soft tissue calcifications was not different among groups (p > 0.05). ART patients showed significantly more C0 (thickening) and C1 MCI (p < 0.05). CONCLUSION: Sclerotic bone pattern and thicker mandibular cortices may represent a consequence of ART rather than MRONJ specific findings. Prospective studies on larger patient samples radiographically followed-up during the ART treatment are advised, with specific attention to heterogenous trabecular bone pattern as a possible MRONJ predictor.

Influence of metal artefact reduction on the diagnosis of contact between implant and mandibular canal in cone beam computed tomography: An ex-vivo study.

OBJECTIVE: To evaluate the influence of metal artefact reduction (MAR) in the diagnosis of dental implant contact with the mandibular canal (MC) using cone beam computed tomography (CBCT). METHODS: Dental implants were installed with surgical guides in the posterior hemiarches of 10 dry human mandibles: 0.5 mm above to the MC cortex (G1/n = 8) and 0.5 mm inside the MC (G2/n = 10). The experimental set-up was scanned with two CBCT equipment using 85 kV and 90 kV, MAR ON or OFF, and different tube currents (4 mA, 8 mA and 10 mA). Two dentomaxillofacial radiologists (DMFRs) and two dentists (DDS) scored the relation between the dental implant and MC. Descriptive statistics were used to observe the absolute frequency of scores. Sensitivity, specificity and accuracy were calculated considering the known relation between the dental implant and the MC interior. McNemar's test (α = .05) was applied to compare the diagnostic efficacy of MAR ON versus MAR OFF. RESULTS: Overall specificity was higher than sensitivity for both DDS and DMFR (97% vs. 50% and 92.0% vs. 78.0% respectively). There was a significant effect of MAR (p = .031) for DMFR in the case of contact between the dental implant with the MC interior, in which sensitivity decreased with MAR activation from 90% to 40%. DMFR observers showed a better diagnostic performance compared with the DDS observers (accuracy of 84.0% and 71.0%, respectively). CONCLUSIONS: Due to the limited efficacy of MAR, it should not be used when conducting CBCT scans for the evaluation of contact between the implant and the mandibular canal.

Convex triangular vs. cylindrical field of view: how does the shape of the FOV affect radiation dose?

OBJECTIVE: To compare the dosimetry between convex triangular fields of view (FOV) and similar dimension cylindrical FOVs of two cone-beam computed tomography (CBCT) models. METHODS: Optically stimulated luminescence dosimeters (OSLDs) were placed in fiducial anatomical locations in an anthropomorphic phantom representing an adult head male for dosimetry scans. Convex triangular FOVs (100 × 80 mm/maxilla-mandible; 100 × 50 mm mandible; 100 × 50 mm/maxilla) from Veraviewepocs 3D R100 (J. Morita, Kyoto, Japan) (R100) and Veraview® X800 (J. Morita, Kyoto, Japan) (X800) and cylindrical FOVs from R100 and X800 (80 × 80 mm/maxilla-mandible; 80 × 50 mm/mandible; 80 × 50 mm/maxilla) were obtained, resulting in 12 different scan protocols. Equivalent doses for each relevant organ/tissue and the effective dose for each protocol were calculated. Mean effective doses were compared by the two-way analysis of variance (ANOVA) with Tukey's post hoc test to evaluate the effect of the FOV and device (α = 0.05). RESULTS: The effective doses ranged between 69 and 324 µSv for the convex triangular FOVs and 76 and 332 µSv for the cylindrical FOVs. Convex triangular FOVs from the R100 device had effective doses 2.3 to 15.3% lower than their corresponding cylindrical FOVs with similar height (p < 0.05), and that difference ranged between 8.8 and 11.8% for the X800 device (p < 0.05). CONCLUSION: Convex triangular fields of view delivered slightly lower effective doses than the cylindrical fields of view of similar dimensions in the R100 and X800 CBCT devices. CLINICAL RELEVANCE: Understanding the influence of the image geometry formation in effective dose allows optimization to reduce patient dose.

Do cone-beam computed tomography low-dose protocols affect the evaluation of the temporomandibular joint?

BACKGROUND: There is no established acquisition protocol based on scientific evidence for the acquisition of cone-beam computed tomography (CBCT) exams to evaluate the temporomandibular joint (TMJ). OBJECTIVES: To evaluate the influence of acquisition protocols and jaw positioning on the diagnostic accuracy of TMJ condylar morphological alterations (CMA), dimension, position and excursion. METHODS: Thirty-six TMJs on 18 dry skulls were imaged using a CBCT unit (OP300 Maxio, Instrumentarium, Tuusula, Finland) at two exposure settings (4.5 and 6.3 mA), three voxel resolutions (0.085, 0.125 and 0.280 mm), three jaw positions (concentric, anteriorised and posteriorised) and three jaw excursions (normoexcursion, hyperexcursion and hypoexcursion). The macroscopic anatomy examination and high-resolution CBCT images were used as ground truth for CMA. Twenty-five TMJs had at least one CMA with 11 healthy TMJs serving as controls. Three experienced oral and maxillofacial radiologists evaluated the parasagittal images for the presence of CMA, position and excursion and measured dimensions. The area under the ROC curve, sensitivity and specificity were calculated. Weighted Kappa (α = 0.05) was used to determine intra- and interexaminer reliability and comparisons between dependent variables analysed by Analysis of Variance at an a prior level of significance of 0.05. RESULTS: The agreement of the evaluation of the position and excursion with the reference standard was high, independent of the protocol (range, 0.75-0.91). Various combinations of acquisition protocols and jaw position did not influence the CMA evaluation. Erosion was overdiagnosed in protocols with larger voxel sizes and the detection of osteophytes greater in images with smaller voxel sizes. The anteroposterior dimension was greater in the open jaw position (p < .05). CONCLUSION: CBCT protocols using reduced radiation exposure from the CBCT machine evaluated in this study can be used to assess condylar morphology, dimension, position and excursion, without compromising diagnostic performances for these parameters.

The impact of digital filters on the diagnosis of simulated root resorptions in digital radiographic systems.

OBJECTIVES: To evaluate the influence of digital filters of intraoral radiographic systems on the diagnosis of simulated internal and external root resorptions and image quality. MATERIALS AND METHODS: Internal root resorption (IRR) and external root resorption (ERR) were simulated in 34 teeth. For image acquisition, two radiographic systems were used: Digora Toto and VistaScan. All filters available in these systems were applied. Three observers scored the detection of root resorptions in a 5-point scale. The noise and the contrast-to-noise ratio (CNR) were calculated. The area under ROC curve, sensitivity, specificity, and accuracy were obtained. One-way ANOVA with Tukey's post hoc tests compared the diagnostic values, noise, and CNR between the filters (α = 0.05). RESULTS: For ERR, there were no significant differences in diagnostic values between the filters tested for both systems. For IRR, Original and Noise Reduction filters presented higher sensitivity than the Sharpen2 filter for images from Digora Toto, with no differences between the other groups. For VistaScan, there were no significant differences of diagnostic values between the groups studied. Noise values differed among the filters of both systems. The CNR of the filters differed only for the bone region for Digora Toto, while for VistaScan, both tooth and bone regions differed. CONCLUSIONS: Despite promoting changes in pixel intensities and affecting the noise level of the radiographic images, the digital filters of Digora Toto and VistaScan systems do not affect the diagnosis of internal or external root resorptions. CLINICAL RELEVANCE: Digital filters are common tools in digital radiographic systems and may be used by the professional without impairment in root resorptions diagnosis.

Evaluation of photobiomodulation therapy to accelerate bone formation in the mid palatal suture after rapid palatal expansion: a randomized clinical trial.

To evaluate the efficiency of photobiomodulation therapy (PBMT) in the midpalatal suture (MPS) and pain sensation in patients undergoing rapid palatal expansion (RPE). Thirty-four individuals with the diagnosis of skeletal maxillary hypoplasia were divided in two groups: laser (n = 18) and control (n = 16). Treatment plan consisted of the use of the Hyrax expander in all patients. Subjects in the laser group were irradiated with diode laser (980 nm, 0.3 W) in six spots bilaterally distributed along the MPS for 10 s during the active phase of treatment and after overcorrection (passive phase of RPE). Control group received sham irradiations with the laser in standby mode to characterize the placebo effect. Digital occlusal radiographs were performed at different time-points for bone formation evaluation in both groups. The effects of laser irradiation on pain were assessed by the visual analog scale (Wong-Baker Faces Pain Scale). Bone formation between groups was not significantly different (p = 0.2273). At 3 months, bone formation was not yet complete in both groups. Pain sensation was similar between groups (p = 0.3940). However, pain was significantly higher for the first 7 days of treatment compared with the 14th day. PBMT did not accelerate bone regeneration in the MPS and pain sensation was similar.

Artefacts at different distances from titanium and zirconia implants in cone-beam computed tomography: effect of tube current and metal artefact reduction.

OBJECTIVES: To evaluate the effect of cone-beam computed tomography (CBCT) tube current (mA) on the magnitude of artefacts at different distances from titanium or zirconia implants, with and without activation of a proprietary metal artefact reduction (MAR). MATERIAL AND METHODS: Human mandibles were scanned on an OP300 Maxio CBCT unit (Instrumentarium, Tuusula, Finland) before and after the installation of dental implants, with four different tube currents (4 mA, 6.3 mA, 8 mA and 10 mA), with and without activation of proprietary MAR. The effect of mA on the standard deviation (SD) of gray values and contrast to noise ratio (CNR) were assessed in regions of interest located 1.5 cm, 2.5 cm, and 3.5 cm from implants. RESULTS: In the presence of titanium implants, a significant decrease in SD was found by increasing tube current from 4 mA to 6.3 mA or 8 mA. For zirconia implants, 8 mA yielded better results for all distances. MAR improved CNR in the presence of zirconia implants at all distances, whereas no differences were observed with the use of MAR for titanium implants. CONCLUSION: Increased tube current can improve overall image quality in the presence of implants, at all the distances tested. When a zirconia implant is present, such increase in mA should be higher in comparison to that for examinations with titanium implants. Activation of OP300 Maxio proprietary MAR improved image quality only among examinations with zirconia implants. CLINICAL RELEVANCE: Artefact-generating implants are common in the field of view of CBCT examinations. Optimal exposure parameters, such as tube current, ensure high image quality with lowest possible radiation exposure.

Do the number of basis images and metal artifact reduction affect the production of artifacts near and far from zirconium dental implants in CBCT?

OBJECTIVES: This study aimed to evaluate the influence of the number of basis images and the metal artifact reduction (MAR) tool on the production of artifacts near and far from a zirconium implant in cone-beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT scans of a mandible were acquired before and after insertion of an implant, using 450 and 720 basis images, with and without MAR activation. The mean and standard deviation (SD) of the gray values of the regions of interest (ROIs) located on the cortices adjacent to the implant and at different distances from it (in the soft tissue) were calculated. The mean of the gray values was used to calculate the absolute contrast difference (ACD) between the control and implant scans. RESULTS: In general, the number of basis images did not affect the SD and the ACD values of the buccal and lingual ROIs (p > 0.05). The implant increased the SD in the lingual cortical plate (p < 0.05). In this case, MAR activation decreased SD (p < 0.05). All ROIs located at different distances from the implant showed higher SD on scans acquired with 450 basis images (p < 0.05), regardless of MAR condition. CONCLUSIONS: A higher number of basis images reduces the magnitude of artifacts but does not influence the image quality in bone cortical plates. MAR improves the image in the areas most affected by artifacts. CLINICAL RELEVANCE: The number of basis images is known as a factor capable of influencing the image quality and radiation dose for the patient. Therefore, it is important to investigate its effect on the expression of artifacts in the CBCT images.

Effect of digital enhancement on the radiographic assessment of vertical root fractures in the presence of different intracanal materials: an in vitro study.

OBJECTIVES: To evaluate the effect of enhancement tools of intraoral digital radiographs on the assessment of vertical root fracture (VRF) and to quantify the resultant image noise. MATERIALS AND METHODS: Thirty single-rooted human teeth (15 control and 15 fractured) were each radiographed in four intracanal conditions: no filling, gutta-percha, metal post, and fiberglass post, totaling 120 original images. Two filters were applied to the original images-Sharpen filter (SF) and Edge Enhancement filter (EE), and brightness and contrast were adjusted in four combinations (B&C1 to 4), resulting in 840 images. Five oral radiologists analyzed the images for VRF detection. Pixel intensity was obtained in two regions from the radiographs. Diagnostic values were calculated and compared by two-way ANOVA, and the SD values of pixel intensity values were compared by one-way ANOVA (α = 0.05). RESULTS: There were no significant differences in accuracy for VRF detection between the experimental groups (p > 0.05). Teeth with metal post presented the lowest sensitivity (p < 0.05) for all experimental conditions, except for SF and EE (p > 0.05). B&C2, B&C3, and B&C4 had higher specificity than SF (p ≤ 0.05) for all intracanal conditions. Analysis of pixel intensity showed that all enhanced images presented statistically significant higher noise compared to those of the original images (p ≤ 0.05). CONCLUSION: Digital enhancement tools in digital radiography increase image noise; however, they can be used without compromising VRF detection. CLINICAL RELEVANCE: The use of digital enhancement does not impair the detection of VRF and, therefore, can be applied for this purpose according to the observer preference.

Early imaging signs of the use of antiresorptive medication and MRONJ: a systematic review.

OBJECTIVE: The main aim is to identify, by means of different imaging modalities, the early bone changes in patients "at risk" and in stage 0 MRONJ. MATERIALS AND METHODS: A search of the literature was performed on PubMed, Embase, Web of Science, and Cochrane Library databases, until June 9, 2020. No language or year restrictions were applied. Screening of the articles, data collection, and qualitative analysis was done. The Newcastle-Ottawa Scale (NOS) was used for observational studies, and the Systematic Review Centre for Laboratory Animal Experimentation's (SYRCLE) risk of bias tool for the animal studies. RESULTS: A total of 1188 articles were found, from which 47 were considered eligible, whereas 42 were suitable for the qualitative analysis. They correspond to 39 human studies and 8 animal studies. Radiographic findings such as bone sclerosis, osteolytic areas, thickening of lamina dura, persisting alveolar socket, periapical radiolucency, thicker mandibular cortex, widening of the periodontal ligament space, periodontal bone loss, and enhancement of the mandibular canal were identified as early bone changes due to antiresorptive therapy. All those findings were also reported later in Stage 0 patients. CONCLUSION: The main limitations of these results are the lack of prospective data and comparisons groups; therefore, careful interpretation should be made. It is a fact that radiographic findings are present in antiresorptive-treated patients, but the precise timepoint of occurrence, their relation to the posology, and potential risk to develop MRONJ are not clear. CLINICAL RELEVANCE: The importance of a baseline radiographic diagnosis for antiresorptive-treated patients.

Retrospective assessment of dental implant-related perforations of relevant anatomical structures and inadequate spacing between implants/teeth using cone-beam computed tomography.

OBJECTIVES: To assess the prevalence of dental implant-related perforations of relevant anatomical structures and inadequate spacing between the implant and the adjacent tooth or implant, and their association with anatomical location, implant dimension, thread exposure, and presence of graft, using cone beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT scans of patients with implants were retrospectively assessed regarding the presence of implant-related perforation of adjacent anatomical structures, and inadequate mesial and distal spacing between the implant and the adjacent tooth/implant (i.e., < 1 mm or < 3 mm, respectively). Implants were classified according to anatomical location, dimensions, thread exposure, and the presence of graft (i.e., bone graft or bone substitutes). Prevalence of perforations and inadequate spacing was compared among the different implant classifications (Chi-squared test). Significance level was set at 5%. RESULTS: A total of 1109 implants were assessed, out of which 369 (33.3%) presented perforation of adjacent structures. Prevalence of perforations in the maxilla (43.5%) was higher than in the mandible (11.3%). Inadequate spacing was found in 18.2% of the mesial and distal measurements, which was more prevalent in the maxilla (p < 0.001). Implants perforating adjacent structures or placed with inadequate spacing presented higher prevalence of thread exposure (p < 0.001). No significant difference was found between the presence of perforations or inadequate spacing and presence of graft (p > 0.05). CONCLUSIONS: Implant-related perforations of relevant anatomical structures and inadequate spacing between the implant and the adjacent tooth/implant are relatively prevalent and more common in the maxilla. Both are associated with threads exposure. CLINICAL RELEVANCE: Information on dental implant-related perforations and inadequate spacing can assist dental surgeons in pre-surgical planning.

Is Panoramic Imaging Equivalent to Cone-Beam Computed Tomography for Classifying Impacted Lower Third Molars?

PURPOSE: Preoperative recognition of the relative position of the mandibular third molars may contribute to more reliable treatment planning, avoiding injuries and decreasing surgical and recovery times. The research questions for this study were as follows: 1) Is panoramic radiography (PR) equivalent to cone-beam computed tomography (CBCT) in determining the degree of mandibular third molar impaction? 2) For PR, is the external oblique ridge a more reliable reference to determine the degree of mandibular third molar impaction? MATERIALS AND METHODS: This retrospective case-series study assessed whether the imaging modalities (primary predictor variable) are equivalent in determining the degree of impaction of third molars (primary outcome variable) according to the parameters of the Pell and Gregory classification. Two oral and maxillofacial radiologists evaluated PR and CBCT images presenting at least 1 mandibular third molar. The degrees of impaction related to the ascending ramus and related to the external oblique ridge (secondary outcome variables) also were assessed. The agreement rates between PR and CBCT were presented, and the imaging modalities were compared by the McNemar-Bowker test (α = .05). RESULTS: A total of 173 patients were included (66 male and 107 female patients). Among these patients, 313 mandibular third molars were assessed. In relation to the occlusal plane, the agreement rate between PR and CBCT was 82.1% for Pell and Gregory class A, 90.5% for class B, and 65.6% for class C (P = .116). The overall agreement rate between the classifications in relation to the mandibular ramus on PR and CBCT ranged from 66.8% (considering the ascending ramus, P < .001) to 76.4% (considering the external oblique ridge, P < .001). CONCLUSIONS: PR performs similarly to CBCT in the classification of impaction in relation to the occlusal plane. However, PR shows a tendency to underestimate the space for accommodation of the third molar compared with CBCT. Furthermore, the external oblique ridge is not a reliable alternative landmark on PR.

Effect of brightness and contrast variation for detectability of root resorption lesions in digital intraoral radiographs.

OBJECTIVES: To evaluate the performance of periapical radiography assessed under different radiographic brightness and contrast variations in the detection of simulated internal (IRR) and external (ERR) root resorption lesions. Additionally, observers' preferences related to image quality for these diagnostic tasks were evaluated. METHODS: Thirty single-root teeth were divided into two groups (n = 15): IRR, in which lesions were simulated using mechanical and biochemical processes; and ERR, in which cavities standardized with drills of different sizes were performed on the root surfaces. Digital radiographs were obtained and subsequently adjusted in 4 additional combinations, resulting in 5 brightness/contrast variations (V1-V5). Five radiologists evaluated the radiographs. The observers' preference on the image quality was also recorded. RESULTS: For both conditions, there were no differences in the accuracy and specificity between the five brightness/contrast variations (p > 0.05), but the sensitivity for ERR was significantly lower in V4 (+ 15% brightness/-15% contrast) in the large size (p < 0.05). The observers classified V2 (- 15% brightness/+15% contrast) as the "best" image quality for IRR and ERR evaluation. CONCLUSIONS: For IRR and ERR lesions, brightness and contrast variation does not affect the diagnostic performance of digital intraoral radiography within the tested range. The observers prefer images with a reasonable decrease in brightness and increase in contrast. CLINICAL RELEVANCE: Brightness and contrast enhancement tools are commonly applied in digital radiographic assessment. The use of these tools for detection of root resorptions can be applied according to the observer preference without influence on diagnostic accuracy.

Influence of 2D vs 3D imaging and professional experience on dental implant treatment planning.

OBJECTIVES: This study investigated whether professional experience and type of image examination (panoramic radiography (PAN) or cone beam computed tomography (CBCT)) could influence the pre-surgical planning for dental implant treatment. MATERIALS AND METHODS: Six dentists, from two different levels of experience (senior (Sr) and junior (Jr)) performed simulated pre-surgical planning by using PANs and after 1 month, by using CBCTs, considering implant length (IL), implant width (IW), need for bone graft (BG), and other surgical procedures (OP). Bland-Altman test and Kappa coefficient were used to identify agreements. RESULTS: Bland-Altman test showed good agreement in the plans for inter-professional (i.e., Sr vs Jr) comparisons. Bland-Altman plots displayed intra-observer agreement (i.e., differences between PAN and CBCT), showing discrepancy between imaging modalities for IL and a tendency towards selecting larger dental implant options when using PAN and smaller options with CBCT. Kappa showed almost perfect (0.81-1.0) agreement between Jr and Sr for OP (PAN and CBCT). For BG, agreement was substantial (0.61-0.80) when planning was done with PAN and CBCT. Descriptive statistics showed evidence that when Jrs used CBCT, they no longer indicated the BG they had planned when they used PAN. CONCLUSION: There were differences in the pre-surgical planning for treatment with dental implants depending on the professional experience and the type of imaging examination used. CLINICAL RELEVANCE: Variation in dental implant planning can affect treatment time, cost, and morbidity in patients.

The effect of electronic cigarettes on dental enamel color.

OBJECTIVE: The use of electronic cigarettes (ECIGs) has recently increased as an alternative to conventional smoking tobacco products. The literature is scarce on the effects of ECIGs on dental and oral structures. Therefore, the objective of this study was to observe whether ECIG aerosol could alter the color of dental enamel. MATERIALS AND METHODS: Sixty-three bovine enamel specimens were randomly separated into groups (n = 7) and treated with aerosols with different e-liquid flavors (neutral, menthol, and tobacco) and nicotine content (0, 12, and 18 mg). The initial color assessment was performed using a spectrophotometer (Easy Shade-Vita). Dental enamel was exposed to 20 cycles of ECIG aerosol in a smoking machine, and the final color was measured. The color change was evaluated using ΔEab, ΔE00, and Whiteness Index (WID ) formulae. Differences in L* a* b* coordinates were calculated, and data were analyzed (two-way ANOVA, uncorrected Fisher's LSD post hoc test, α = 0.05). RESULTS: Luminosity (ΔL) was reduced by aerosols with almost all levels of nicotine content and neutral and menthol flavors. Flavored e-liquids caused more color change (P < .05) according to ΔEab and ΔE00. ΔE values from both formulae exceeded the thresholds for perceptible visual alterations of color. WID increased after ECIGs exposure for menthol and tobacco and decreased for neutral flavors. CONCLUSIONS: ECIG aerosol from e-liquids with different nicotine contents and flavors altered enamel color. Menthol and tobacco e-liquids may alter the enamel color decreasing the yellowness of the enamel compared to neutral e-liquid. CLINICAL SIGNIFICANCE: Electronic cigarettes can cause perceptible changes in tooth color, altering dental esthetics.

Interactive audience response systems in oral and maxillofacial radiology undergraduate lectures.

OBJECTIVES: To evaluate the impact of audience response systems (ARS) on student participation (SP) during Oral and Maxillofacial Radiology (OMR) undergraduate lectures and on final examination scores (FES). Furthermore, an analysis of unanimity assessed the influence of ARS on students' responses. Students' perceptions were also assessed. METHODS: A controlled crossover study was designed. Four lectures covering topics of OMR were each taught with ARS and without ARS (i.e. hand-raising method). SP and FES were compared between ARS and HR groups. Unanimity of answers was analyzed for both groups. Questionnaires assessed students' impressions about ARS. RESULTS: Mean SP of ARS and HR groups were 97.6% and 47.3%, respectively, and this difference was statistically significant (P<.05). Mean FES for the ARS group (77%) was slightly higher than HR group (75.1%), however, not statistically significant. There was positive correlation between SP and FES. With ARS, only 5.7% of the questions were unanimous, whilst 51.4% were unanimous with HR method. Most students reported that the use of ARS had positive influence on their attention (92%), participation (96%), classmates' participation (82.7%), interest (74.7%), and learning (86.7%). For the five-point scale ratings of the relevance of ARS features, anonymity had an average 3.6, whilst other items received an average 4.6 or higher. CONCLUSIONS: ARS significantly increased participation in OMR lectures; however, an increase in FES could not be associated with ARS by itself. Not taking into consideration which method was used to answer questions posed during lectures, higher participation correlated with higher scores. ARS is well-accepted and students believe that these devices positively influence their performance. Among the recognized advantages of ARS, anonymity was considered the least relevant.

Mandibular Osteolytic Lesion Associated with Exuberant Hyaline Ring Granuloma Reaction.

OBJECTIVE: To report an unusual case of oral hyaline ring granuloma (HRG) that caused an extensive osteolytic lesion. CLINICAL PRESENTATION AND INTERVENTION: A 22-year-old female was referred to our hospital with a large expansile cystic lesion in the left mandibular ramus associated with a clinically visible, partially erupted third molar. A diagnosis of paradental cyst was made. After marsupialization of the lesion, histopathological analysis of the surgical specimen showed an unusual exuberant HRG reaction supported by scarce fibrous stroma. CONCLUSION: This was a case of exuberant HRG reaction that caused extensive bone destruction.