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.

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.

Assessment of accuracy and reproducibility of cephalometric identification performed by 2 artificial intelligence-driven tracing applications and human examiners.

OBJECTIVE: To assess the accuracy and reproducibility of cephalometric landmark identification performed by 2 artificial intelligence (AI)-driven applications (CefBot and WebCeph) and human examiners. STUDY DESIGN: Lateral cephalometric radiographs of 10 skulls containing 0.5 mm lead spheres directly placed at 10 cephalometric landmarks were obtained as the reference standard. Ten radiographs without spheres were obtained from the same skulls for identification of cephalometric points performed by the AI applications and 10 examiners. The x- and y-coordinate values of the cephalometric points identified by the AI applications and examiners were compared with those from the reference standard images using one-way analysis of variance and the Dunnet post-hoc test. The intraclass correlation coefficient (ICC) was used to evaluate reproducibility. Mean radial error (MRE) in identification was calculated with respect to the reference standard. Statistical significance was established at P < .05. RESULTS: Landmark identification by CefBot and the examiners did not exhibit significant differences from the reference standard on either axis (P > .05). WebCeph produced a significant difference (P < .05) in 4 and 6 points on the x- and y-axes, respectively. Reproducibility was excellent for CefBot and the examiners (ICC ≥ 0.9943) and good for WebCeph (ICC ≥ 0.7868). MREs of CefBot and the examiners were similar. CONCLUSION: With results similar to those of human examiners, CefBot demonstrated excellent reliability and can aid in cephalometric applications. WebCeph produced significant errors.

Metaverse and oral and maxillofacial radiology: Where do they meet?

Since previous literatureregarding the application of the metaverse in educationis scarce, the present letter aimed to highlight possible applications, as a complementary tool for the classroom, in the oral and maxillofacial radiology academic experience.Thepotential risksof the metaverse are also discussed. The metaverse and its possible applications, especially related to enhanced teaching and learning, will become a hot topic in the near future, and therefore, there will be a challenging learning curve before the educator makes the most of these innovative educational tools empowered by deeply interactive virtual reality technology.

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.

Filtered back projection vs. iterative reconstruction for CBCT: effects on image noise and processing time.

OBJECTIVES: To assess the effect of standard filtered back projection (FBP) and iterative reconstruction (IR) methods on CBCT image noise and processing time (PT), acquired with various acquisition parameters with and without metal artefact reduction (MAR). METHODS: CBCT scans using the Midmark EIOS unit of a human mandible embedded in soft tissue equivalent material with and without the presence of an implant at mandibular first molar region were acquired at various acquisition settings (milliamperages [4mA-14mA], FOV [5 × 5, 6 × 8, 9 × 10 cm], and resolutions [low, standard, high] and reconstructed using standard FBP and IR, and with and without MAR. The processing time was recorded for each reconstruction. ImageJ was used to analyze specific axial images. Radial transaxial fiducial lines were created relative to the implant site. Standard deviations of the gray density values (image noise) were calculated at fixed distances on the fiducial lines on the buccal and lingual aspects at specific axial levels, and mean values for FBP and IR were compared using paired t-tests. Significance was defined as p < 0.05. RESULTS: The overall mean for image noise (± SD) for FBP was 198.65 ± 55.58 and 99.84 ± 16.28 for IR. IR significantly decreased image noise compared to FBP at all acquisition parameters (p < 0.05). Noise reduction among different scanning protocols ranged between 29.7% (5 × 5 cm FOV) and 58.1% (5mA). IR increased processing time by an average of 35.1 s. CONCLUSIONS: IR significantly reduces CBCT image noise compared to standard FBP without substantially increasing processing time.

ChatGPT: a tool for scientific writing or a threat to integrity?

The use of ChatGPT as a tool for writing and knowledge integration raises concerns about the potential for its use to replace critical thinking and academic writing skills. While ChatGPT can assist in generating text and suggesting appropriate language, it should not replace the human responsibility for creating innovative knowledge through experiential learning. The accuracy and quality of information provided by ChatGPT also require caution, as previous studies have reported inaccuracies in references used by chatbots. ChatGPT acknowledges certain limitations, including the potential for generating erroneous or biased content, and it is essential to exercise caution in interpreting its responses and recognize the indispensable role of human experience in the processes of information retrieval and knowledge creation. Furthermore, the challenge of distinguishing between papers written by humans or AI highlights the need for thorough review processes to prevent the spread of articles that could lead to the loss of confidence in the accuracy and integrity of scientific research. Overall, while the use of ChatGPT can be helpful, it is crucial to raise awareness of the potential issues associated with the use of ChatGPT, as well as to discuss boundaries so that AI can be used without compromising the quality of scientific articles and the integrity of evidence-based knowledge.

Maxillary Parosteal Osteosarcoma: Additional case Report and Literature Review of Surface Osteosarcomas.

Introduction: Surface osteosarcomas represent around 3-6% of all osteosarcomas, which include the parosteal (low-grade), periosteal (intermediate-grade) and high-grade surface osteosarcomas. The classical location is the femur, followed by tibia and humerus. Parosteal osteosarcoma is the most common type of surface osteosarcoma. To date, 26 cases of parosteal osteosarcoma affecting the jaws have been reported, with most cases following an evolution time of several months to years, clinically favoring a benign osseous or fibro-osseous lesion. Methods: Here, we report a 39-year-old female who was referred presenting a maxillary tumoral mass 5 years ago, clinically diagnosed as osteoma. After clinical, imaginological and histopathological analysis, a diagnosis of parosteal osteosarcoma was made. Conclusion: Thus, parosteal osteosarcoma should also be considered in the differential diagnosis of benign-appearance, bone-forming nodular lesions affecting the jaws.

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.

Retromolar canal diagnosed by cone-beam computed tomography and its influence in inferior alveolar nerve block / Canal retromolar diagnosticado por tomografía computarizada de haz cónico y su influencia en el bloqueo del nervio alveolar inferior

The aim of this study was to observed the anesthetic efficacy of the alveolar nerve block on nine patients that CBCT diagnosed unilateral retromolar canal on a double-blind, split-mouth approach. The assessments of patient response to thermal (pulp vitality test) and pressure (compression of soft tissue) stimuli were carried out before and 5 minutes after the inferior alveolar nerve block procedure, using both visual analog scale (VAS) and Mc Gill pain questionnaires (McG). The mean percentage of patient response decreased after alveolar nerve block, according to both VAS and McG, and was statistically similar among hemi mandibles with and without retromolar canal (Wilcoxon>0.05); however, those without retromolar canal presented greater reduction in patient response in 6 out of 9 cases. Therefore, the retromolar canal is not a determinant factor of inferior alveolar nerve block failure.

El objetivo de este estudio fue observar la eficacia anestésica del bloqueo del nervio alveolar en nueve pacientes que CBCT diagnosticó canal retromolar unilateral en un abordaje de boca dividida doble ciego. Las evaluaciones de la respuesta del paciente a los estímulos térmicos (prueba de vitalidad pulpar) y de presión (compresión de los tejidos blandos) se realizaron antes y 5 minutos después del procedimiento de bloqueo del nervio alveolar inferior, utilizando tanto la escala analógica visual (VAS) como los cuestionarios de dolor de Mc Gill ( McG). El porcentaje medio de respuesta de los pacientes disminuyó tras el bloqueo del nervio alveolar, según EVA y McG, y fue estadísticamente similar entre hemimandíbulas con y sin canal retromolar (Wilcoxon>0,05); sin embargo, aquellos sin canal retromolar presentaron mayor reducción en la respuesta del paciente en 6 de 9 casos. Por lo tanto, el canal retromolar no es un factor determinante del fracaso del bloqueo del nervio alveolar inferior.

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.

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.

Comparison of intraoral scanning and CBCT to generate digital and 3D-printed casts by fused deposition modeling and digital light processing.

OBJECTIVES: to evaluate trueness and precision of digital casts from intraoral scanning (IOS) and cone beam computed tomography (CBCT); trueness and precision of 3D-printed casts using digital light processing (DLP) and fused deposition modeling (FDM); the influence of digitizing method in the 3D-printed casts and, to compare STL data after DICOM segmentation and conversion. METHODS: a reference cast was digitized with IOS and CBCT, and 3D-printed using FDM and DLP. Linear measurements of occlusocervical (OC), interarch (IEA), and mesiodistal (MD) dimensions were taken on reference, digital and 3D-printed casts. Trueness was observed as the distortion, and precision was observed as the variation of measurements. One and Two-way ANOVA, Student t-test, and Chi-Square were applied to analyze data. RESULTS: distortion varied between digital casts for all dimensions; at OC, both showed expanded dimensions with IOS being significantly greater; in turn, CBCT digital casts showed higher distortion at IEA and MD. Dimensions of 3D-printed casts showed a predominance of shrinkage, DLP presented higher distortion compared to FDM for both digitizing methods. Digitizing methods influenced the 3D-printing of casts, especially for DLP. Regarding precision, no statistical difference was found. STL converted from DICOM showed statistical difference in IEA (p < 0.001). CONCLUSIONS: digital casts showed distortion depending on the digitizing method. IOS was better in IEA and MD, and CBCT in OC dimensions. Overall, DLP casts presented higher distortion compared to FDM. The digitizing method influences trueness on 3D-printed casts. File conversion from DICOM to STL per se could change the dimension. CLINICAL SIGNIFICANCE: This investigation showed that digital casts from IOS and CBCT as well 3D-printed casts from FDM and DLP can show different trueness. It is clinically relevant as clinicians have various workflows available in Digital Dentistry which involve these digitizing and manufacturing methods.

Automatic exposure compensation of digital radiographic technologies does not affect alveolar bone-level measurement.

OBJECTIVE: To evaluate whether the automatic exposure compensation in the presence of high-density materials can affect the measurement of alveolar bone level. METHODS: Thirty regions of seven dry skulls and six mandibles were radiographed with and without a high-density material, using two digital radiographic technologies: photostimulable phosphor plate (PSP, Digora Optime) and sensor (CMOS, Digora Toto), totaling 120 images. The distances from the cement-enamel junction to the alveolar bone crest were measured using cone-beam computed tomography (CBCT) images to represent the reference standard. The same measurements of alveolar bone level and the average of the pixel values of the image were evaluated on the radiographs. Paired t test compared the average pixel values and alveolar bone-level measurements between images with and without high-density material. One-way analysis of variance compared the difference between radiographic and CBCT measurements (α = 0.05). RESULTS: The high-density material reduced the pixel values in PSP (p = 0.002) and CMOS (p < 0.001) technologies, demonstrating the AEC functioning in both technologies. There was no difference in bone-level measurements between the images without and with the high-density material for both technologies (p ≥ 0.091), or between the tomographic and radiographic measurements (p ≥ 0.319). CONCLUSION: In the presence of high-density material, the automatic exposure compensation reduces the average pixel values of the images (i.e., images get darker), but does not influence the radiographic measurements of alveolar bone level.

Does the angulation between the maxillary central incisors and the nasopalatine canal differ among sagittal and vertical skeletal patterns? A CBCT study.

OBJECTIVES: To assess the influence of sagittal and vertical skeletal patterns, and sex in the angulation and relationship between the maxillary central incisors and the nasopalatine canal. MATERIALS AND METHODS: Cone-beam computed tomography (CBCT) exams of 172 patients were classified into sagittal (class I, II, and III) and vertical skeletal patterns (mesofacial, brachyfacial and dolichofacial). Hard palate-nasopalatine canal and hard palate-long axis of maxillary central incisors angles were measured in sagittal reconstructions. The obtained angles were used to calculate the angulation between maxillary central incisors and nasopalatine canal by triangle geometric relationship. Analysis of variance (multi-way ANOVA) and Tukey post-hoc test were used for data analysis (α=5%). RESULTS: Sagittal and vertical skeletal patterns, and sex presented a low influence on the angulation of maxillary central incisors and nasopalatine canal. Dolichofacial class II women showed the greatest hard palate-nasopalatine canal angulations (P<0.05) and maxillary central incisors and nasopalatine canal angulations (P<0.05). Mesofacial class II and III men presented the lowest maxillary central incisors and nasopalatine canal angulations (P<0.05). CONCLUSIONS: The sagittal and vertical skeletal patterns, and sex have a low influence on the angulation of the maxillary central incisors and the nasopalatine canal.

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.

Can the Incorporation of a Lead Foil on the Backside of Digital Receptors Produce a Better Endodontic Diagnosis?

ABSTRACT: This study evaluated influence of addition of lead foil coupled to different types of digital receptors on image noise and on diagnosis of fractured instruments in teeth without and with root filling. Twenty-six molars had their root canals (n=67) cleaned and shaped and were divided into groups with and without root filling and with and without fractured instruments. Images were acquired in PSP and CMOS sensor, with and without addition of a lead foil coupled to the digital receptors. Diagnostic values were obtained by the area under the ROC curve, and one-way ANOVA compared the groups. Noise in images was measured by the standard deviation of mean gray values in images with and without the lead foil, and compared by two-way ANOVA (a=0.05). Addition of lead foil did not interfere in the diagnostic accuracy for both digital systems (p>0.05) and did not decrease noise in the images (p>0.05). However, independently of the addition of the lead foil, the phosphor-storage plate presented higher noise compared to the sensor (p ?0.05). Addition of lead foil to the digital receptor did not interfere in image noise and with the diagnostic accuracy for detecting fracured endodontic instrument in ex-vivo conditions.

RESUMEN: Este estudio evaluó la influencia de láminas de plomo acopladas a diferentes tipos de receptores digitales sobre el ruido de la imagen y el diagnóstico de instrumentos fracturados en dientes sin y con obturación radicular. Se limpiaron y moldearon 26 molares (n = 67), se dividieron en grupos con y sin relleno radicular y con y sin instrumentos fracturados. Las imágenes se adquirieron en el sensor PSP y CMOS, con y sin adición de una lámina de plomo acoplada a los receptores digitales. Los valores diagnósticos se obtuvieron por el área bajo la curva ROC y con ANOVA de una vía comparó los grupos. El ruido en las imágenes se midió mediante la desviación estándar de los valores medios de gris en las imágenes con y sin la lámina de plomo, y se comparó mediante ANOVA bidireccional (a = 0,05). La adición de lámina de plomo no interfirió en la precisión diagnóstica de ambos sistemas digitales (p> 0,05) y no disminuyó el ruido en las imágenes (p> 0,05). Sin embargo, independientemente de la adición de la lámina de plomo, la placa de almacenamiento de fósforo presentó mayor ruido en comparación con el sensor (p?0,05). La adición de lámina de plomo al receptor digital no interfirió con el ruido de la imagen y con la precisión diagnóstica para detectar el instrumento endodóntico fracturado en condiciones ex vivo.

Comparison of distance of upper central incisor root and incisive canal in different sagittal and vertical skeletal patterns and sex: A retrospective CBCT study.

INTRODUCTION: To evaluate the influence of sagittal and vertical skeletal patterns (skeletal classes and facial profiles), and sex on the distance between upper central incisors roots and incisive canal. MATERIAL AND METHODS: Cone-beam computed tomography exams of 172 patients were classified into skeletal classes I, II, and III and according to the facial profile into mesofacial, brachyfacial, and dolichofacial. In sagittal reconstructions, linear measurements were done between central incisors roots and incisive canal at three levels: incisive foramen opening, intermediate region, and the region close to the apex of upper central incisors. In axial reconstructions, measurements of incisive canal width and distance between the roots were obtained. Analysis of Variance (three-way ANOVA) was used to evaluate measurement differences in relation to skeletal classes, facial profiles, and sex. RESULTS: The distance between upper central incisors roots and incisive canal anterior region was little influenced by sagittal and vertical skeletal patterns and sex. Men had significantly greater incisive canal (mean=2.85mm; SD=1.18) width compared to women (mean=2.40mm; SD=1.04), regardless of skeletal class and facial profile (P<0.05). In general, inter-root distance between medial points of central incisors roots and incisive canal opening was greater in the region close to upper central incisors apex (mean=3.84mm; SD=1.44) than in incisive foramen opening (2.44mm; SD=1.04), (P<0.05). CONCLUSIONS: The distance between upper central incisors roots and incisive canal is little influenced by sagittal and vertical skeletal patterns and sex.

Why do some extraction sites develop medication-related osteonecrosis of the jaw and others do not? A within-patient study assessing radiographic predictors.

PURPOSE: To compare radiographic predictors of medication-related osteonecrosis of the jaw in dental extraction sites. MATERIALS AND METHODS: Forty-one oncological patients undergoing intravenous or subcutaneous antiresorptive treatment, with a history of dental extraction visualised by panoramic imaging, were included in this retrospective study. Age-, sex- and extracted tooth-matched healthy patients who had previously undergone panoramic imaging were selected as controls (n = 57). A total of 288 extraction sites were independently evaluated by two oral and maxillofacial radiologists, who assessed eight distinct radiographic features. The radiographic features of extraction sites were noted to allow comparison between and within subjects regarding healing and osteonecrosis development. The association between radiographic findings, underlying dental disease and medication-related osteonecrosis of the jaw was also tested. The level of significance was set at 5%. RESULTS: Patients under antiresorptive treatment presented with widening of the periodontal ligament space, thickening of the lamina dura, sclerotic bone pattern, horizontal bone loss and periapical radiolucency with bone reaction (P ≤ 0.05). Development of medication-related osteonecrosis of the jaw was associated with altered bone pattern, angular bone loss, furcation involvement and unsatisfactory endodontic treatment (P ≤ 0.05). An association between medication-related osteonecrosis of the jaw and previous dental disease was also found, particularly for periapical lesions and endodontic-periodontal disease (P ≤ 0.05). CONCLUSIONS: Radiographic predictors of further development of medication-related osteonecrosis of the jaw in extraction sites include heterogeneous bone pattern, angular bone loss and furcation involvement. Extraction sites with underlying bony changes related to endodontic and endodontic-periodontal disease are more prone to development of medication-related osteonecrosis of the jaw.

Combined Use of 2 Cone-beam Computed Tomography Scans in the Assessment of Vertical Root Fracture in Teeth with Intracanal Material.

INTRODUCTION: The purpose of this preliminary study was to evaluate the diagnostic accuracy of the combined use of 2 cone-beam computed tomographic (CBCT) volumes obtained with the tooth of interest positioned at different orientations in the detection of vertical root fracture (VRF). METHODS: Thirty single-rooted teeth were divided into 2 main groups (n = 15): control and with VRF. The teeth were individually placed in a phantom composed of a human skull and mandible, which was CBCT scanned in 2 spatial orientations: conventional (with the Frankfurt plane parallel to the floor) and angled acquisition (tilted 90° backward). Also, each tooth was scanned with gutta-percha, a metal post, and without any intracanal material. Three oral radiologists individually evaluated the images resulting from conventional acquisition and verified the presence or absence of VRF (conventional CBCT assessment), setting a score on a 5-point scale. Subsequently, the observers evaluated both images resulting from the conventional and angled acquisitions (combined CBCT assessment). The diagnostic values of the conventional and combined assessments were compared using 2-way analysis of variance with the post hoc Tukey test. The significance level was set at 5% (α = 0.05). RESULTS: The combined CBCT assessment showed higher accuracy and sensitivity in the VRF diagnosis of teeth filled with gutta-percha (P < .05). In teeth with a metal post, all diagnostic values were higher in the combined CBCT assessment (P < .05). CONCLUSIONS: This preliminary study suggests that the CBCT-based diagnosis of VRF in teeth with intracanal material was improved when the assessment combines images obtained at 2 orientations.