Recent advances in imaging technologies in dentistry

Diagnostic Accuracy of Caries and Periapical Lesions on a Monitor with and without DICOM-GSDF Calibration Under Different Ambient Light Conditions

To evaluate the diagnostic accuracy of caries and periapical lesions on a monitor with and without DICOM part 14: grayscale standard display function (DICOM-GSDF) calibration under different ambient light conditions. Forty digital bitewing radiographs were selected, with or without radiographic images of carious lesions and forty digital periapical radiographs with or without periapical lesions were selected from archives of the Radiology Department at the University Hospital of the Federal University of Sergipe. The gold standard radiographic images were determined through consensus between two radiologists with more than 15 and 30 years of experience. The selected radiographs were evaluated on a LG LED monitor with and without DICOM-GSDF calibration under different ambient light conditions: Lx1 (low ambient lighting), Lx2 (moderate ambient lighting) and Lx3 (high ambient lighting). Kappa (K_w) values determined that evaluator 1 showed almost perfect agreement for all devices, while evaluator 2 presented a substantial agreement for all devices. Monitors with and without DICOM-GSDF calibration have similar accuracy values. The three ambient light conditions analyzed have similar accuracy and can be used for caries lesions diagnosis (p > 0.05); however, the best diagnostic accuracy of periapical lesions was found in Lx 2. The displays with and without DICOM-GSDF calibration studied in this research have similar accuracy and can be used to evaluate digital radiographs without changing the diagnostic capacity. The different ambient lighting conditions did not influence the evaluation of caries lesions. The best diagnostic accuracy of periapical lesions was found in moderate ambient lighting.

Multiple Regression Modeling for Age Estimation by Assessment and Comparison of Spheno-Occipital Synchondrosis Fusion and Cervical Vertebral Maturation Stages

Objectives The aim of this study was (1) to evaluate the relationship between spheno-occipital synchondrosis (SOS) fusion stages, cervical vertebral maturation (CVM) stages, and clivus sizes with chronological age on cone-beam computed tomography (CBCT) images, and (2) to compare these methods for accurate age estimation using regression analysis.

Methods The CBCT images of 200 individuals (102 females and 98 males) were included in the study. The SOS fusion stages and CVM stages were evaluated. The width and length of the clivus were measured. The effects of SOS fusion stages, CVM stages, clivus width, and clivus length on age estimation were evaluated by univariate tests and the effects of coexistence with ANCOVA and regression model. Spearman rank correlation analysis was also used to investigate the relationship between the SOS fusion stage, CVM stage, clivus width, and clivus length.

Results The SOS stages, CVM stages, and clivus width were not shown statistically significant differences between the sexes (p-values = 0.205, 0.162, and 0.277, respectively), whereas clivus length was significantly longer in males (42.9 ± 4.26 mm) than in females (41.04 ± 3.74 mm). Multiple regression analysis showed 80% success when all parameters (SOS fusion stages, CVM stages, clivus width, and clivus length) were taken into consideration.

Conclusion In conclusion, with the use of CVM stages and SOS fusion stages together, an accurate and reliable age estimation can be obtained in forensic medicine.

Mouthwash as a non-invasive method of indocyanine green delivery for near-infrared fluorescence dental imaging

SIGNIFICANCE

X-ray imaging serves as the mainstream imaging in dentistry, but it involves risk of ionizing radiation.

AIM

This study presents the feasibility of indocyanine green-assisted near-infrared fluorescence (ICG-NIRF) dental imaging with 785-nm NIR laser in the first (ICG-NIRF-I: 700 to 1000 nm) and second (ICG-NIRF-II: 1000 to 1700 nm) NIR wavelengths.

APPROACH

Sprague Dawley rats with different postnatal days were used as animal models. ICG, as a fluorescence agent, was delivered to dental structures by subcutaneous injection (SC) and oral administration (OA).

RESULTS

For SC method, erupted and unerupted molars could be observed from ICG-NIRF images at a short imaging time (<1  min). ICG-NIRF-II could achieve a better image contrast in unerupted molars at 24 h after ICG injection. The OA could serve as a non-invasive method for ICG delivery; it could also cause the glow-in-dark effect in unerupted molars. For erupted molars, OA can be considered as mouthwash and exhibits outstanding performance for delivery of ICG dye; erupted molar structures could be observed at a short imaging time (<1  min) and low ICG dose (0.05  mg  /  kg).

CONCLUSIONS

Overall, ICG-NIRF with mouthwash could perform in-vivo dental imaging in two NIR wavelengths at a short time and low ICG dose.

Dual Mode pHRI-teleHRI Control System with a Hybrid Admittance-Force Controller for Ultrasound Imaging

The COVID-19 pandemic has brought unprecedented extreme pressure on the medical system due to the physical distance policy, especially for procedures such as ultrasound (US) imaging, which are usually carried out in person. Tele-operation systems are a promising way to avoid physical human-robot interaction (pHRI). However, the system usually requires another robot on the remote doctor side to provide haptic feedback, which makes it expensive and complex. To reduce the cost and system complexity, in this paper, we present a low-cost, easy-to-use, dual-mode pHRI-teleHRI control system with a custom-designed hybrid admittance-force controller for US imaging. The proposed system requires only a tracking camera rather than a sophisticated robot on the remote side. An audio feedback is designed for replacing haptic feedback on the remote side, and its sufficiency is experimentally verified. The experimental results indicate that the designed hybrid controller can significantly improve the task performance in both modes. Furthermore, the proposed system enables the user to conduct US imaging while complying with the physical distance policy, and allows them to seamlessly switch modes from one to another in an online manner. The novel system can be easily adapted to other medical applications beyond the pandemic, such as tele-healthcare, palpation, and auscultation.

Detection of Dental Diseases through X-Ray Images Using Neural Search Architecture Network

An important aspect of the diagnosis procedure in daily clinical practice is the analysis of dental radiographs. This is because the dentist must interpret different types of problems related to teeth, including the tooth numbers and related diseases during the diagnostic process. For panoramic radiographs, this paper proposes a convolutional neural network (CNN) that can do multitask classification by classifying the X-ray images into three classes: cavity, filling, and implant. In this paper, convolutional neural networks are taken in the form of a NASNet model consisting of different numbers of max-pooling layers, dropout layers, and activation functions. Initially, the data will be augmented and preprocessed, and then, the construction of a multioutput model will be done. Finally, the model will compile and train the model; the evaluation parameters used for the analysis of the model are loss and the accuracy curves. The model has achieved an accuracy of greater than 96% such that it has outperformed other existing algorithms.

Knowledge, Attitude, and Practices of Parents toward Pediatric Dental Radiography

Background Pediatric dental radiography is a field with numerous uses as well as concerns regarding radiation safety. This study was undertaken to assess the knowledge that parents have regarding the same. This questionnaire survey was conducted with the aim of assessing the knowledge, attitude, and practices of parents toward pediatric dental radiography.

Material and Methods In total, 280 questionnaires were answered by parents of children visiting the Pediatric Dental Department. The first 10 questions served to evaluate the knowledge and attitude of parents toward pediatric dental radiography. The last three questions were designed to assess the practices of parents in relation to dental radiography and protective gear. The answers were collected and analyzed.

Results From the survey it was seen that most parents were aware that the harmful effects from dental radiography were minimal (51%). A fairly significant number of parents lacked the knowledge regarding the harmful effects of dental radiography in children compared to adults (63%), in comparison to the harmful effects from cell phones (66%) and in comparison to harmful effects of medical radiography (42%). A fair number of parents seemed to be aware of the detrimental cumulative nature (47%) of radiation. It was found that a large number of parents do not ask for an explanation regarding the need for the dental radiograph for their children before the dental treatment (50%). Most parents (64%) were not aware of the availability of protective gear and very few (16%) requested for it.

Conclusion The parents considered in this study had appreciable knowledge and a positive attitude toward dental radiography. However, a significant lack of knowledge regarding protective gear used for dental radiography among these parents was identified from this study.

Evaluating the X-ray-Shielding Performance of Graphene-Oxide-Coated Nanocomposite Fabric

Exposure to ionizing radiation (IR) during diagnostic medical procedures brings certain risks, especially when experiencing recurrent exposures. The fabrication of nano-based composites, doped with different nanoparticles, have been suggested as effective shielding materials to replace conventional lead-based ones in material sciences and nanotechnology. In this study, commercially available fabrics, used to produce scrubs and gowns for clinical staff, are modified utilizing graphene oxide (GO) nanoparticles using a layer-by-layer (LBL) technique. GO was obtained from graphite through environmentally friendly technology by using a modified-improved Hummers' method without NaNO₃. Lightweight, flexible, air- and water-permeable shielding materials are produced that are wearable in all-day clinical practice. The nanoparticles are kept to a minimum at 1 wt%; however, utilizing the LBL technique they are distributed evenly along the fibers of the fabrics to achieve as much shielding effect as possible. The evaluation of samples is accomplished by simulating real-time routine clinical procedures and the radiographic programs and devices used daily. The GO-coated nanocomposite fabrics demonstrated promising results for X-ray shielding.

Efficacy of low dose and ultra-low dose on the visibility of peri-implant fenestration and dehiscences: a computed tomography study

PURPOSE

This study aimed to evaluate the visibility of peri-implant fenestration and dehiscences on computed tomography (CT) images taken with 2 different doses.

MATERIAL AND METHODS

The defects were created on the apical of 6 implants randomly selected from 20 titanium implants placed in the ribs, and dehiscences were created on the cervical of 8 implants. No defects were created around 6 implants. Macroscopic analysis of the implanted ribs was accepted as the gold standard. From the samples, images were taken by using both ultra-low dose (80 kVp, 50 mA, 1.25 mm slice thickness) and low dose (100 kVp, 50 mA, 1.25 mm slice thickness) protocols in CT. The images obtained were evaluated using a 5-point scale.

RESULTS

No significant difference was found between the area under the receiver operating characteristic of ultra-low dose protocol and low dose protocol in both defects based on the Wilcoxon test (p > 0.05).

CONCLUSIONS

The ultra-low dose protocol could be applied by adhering to the "as low as reasonably achievable" principle in the diagnosis of peri-implant defects.

Magnetic resonance imaging versus cone beam computed tomography in diagnosis of periapical pathosis – A systematic review

Objective

The diagnosis of any dental pathology can vary from being simple to challenging. While the use of cone beam computed tomography (CBCT) is well established, magnetic resonance imaging (MRI) remains a proof of concept. This systematic review aims to compare the diagnostic ability of MRI with CBCT in diagnosing periapical pathosis.

Materials and Methods

This systematic search was performed using the electronic databases of MEDLINE, Cochrane Library, Google Scholar, and Science Direct to identify relevant articles from 2010 to 2020. The search terms used were magnetic resonance imaging, cone beam computed tomography, diagnosis, and periapical diseases.

Result

In total, 3218 potentially relevant abstracts and titles were identified. After removing duplicates, 1288 articles were reviewed for titles and abstracts, and 29 articles were selected for full-text reading. From those, 19 articles were finally selected that included original research studies, case reports, and case series and were included for systematic review. Most of the studies included in this review suggested that the combined use of CBCT and MRI is needed for a better and more precise diagnosis of complex periapical pathoses. The main advantage of MRI is its ability to image soft tissues usingnonionizing radiation, and the main disadvantage in the case of CBCT is overdiagnosis of the lesion.

Conclusion

MRI has various advantages over CBCT with similar diagnostic utility. When diagnosing periapical pathogens, both MRI and CBCT are needed for an accurate diagnosis.

Automated chart filing on panoramic radiographs using deep learning

OBJECTIVE

The aim of this study is to automatically detect, segment and label teeth, crowns, fillings, root canal fillings, implants and root remnants on panoramic radiographs (PR(s)).

MATERIAL AND METHODS

As a reference, 2000 PR(s) were manually annotated and labeled. A deep-learning approach based on mask R-CNN with Resnet-50 in combination with a rule-based heuristic algorithm and a combinatorial search algorithm was trained and validated on 1800 PR(s). Subsquently, the trained algorithm was applied onto a test set consisting of 200 PR(s). F1 scores, as a measure of accuracy, were calculated to quantify the degree of similarity between the annotated ground-truth and the model predictions. The F1-score considers the harmonic mean of precison (positive predictive value) and recall (specificity).

RESULTS

The proposes method achieved F1 scores up to 0.993, 0.952 and 0.97 for detection, segmentation and labeling, respectivley.

CONCLUSION

The proposed method forms a promising foundation for the further development of automatic chart filing on PR(s).

CLINICAL SIGNIFICANCE

Deep learning may assist clinicians in summarizing the radiological findings on panoramic radiographs. The impact of using such models in clinical practice should be explored.

Reliability of Photogrammetric Landmarks to the Conventional Cephalogram for Analyzing Soft-Tissue Landmarks in Orthodontics

Background

Graber introduced facial photographs as an internal diagnostic aid. Facial photographs could serve as an important alternative assessment tool in the absence of equipment for cephalometric analysis.

Objectives

The present study was aimed at assessing whether analyzing the photographs could have precision for assessing the landmarks appropriate for facial analysis. In addition, the relationship between frontal cephalogram and measurements on photographs was assessed.

Materials and Methods

Twenty individuals including both males and females within the age range of 18 years to 28 years were enrolled in the study. Frontal facial photographs, as well as frontal cephalograms, were obtained for all the included study participants. Various soft-tissue vertical and horizontal landmarks were marked on both radiographs and photographs. The data were collected and subjected to statistical analysis.

Results

The results showed a statistically insignificant difference between all the vertical and horizontal parameters on photographs and cephalograms. The reliability of the digital photographs was comparable to that of the cephalograms with nonsignificant differences in the recorded mean values using the one-way ANOVA test where the statistical significance level was kept at P ≤ 0.05.

Conclusion

The present study concluded that photography is a cost-effective and reliable method for soft-tissue landmark identification, and allows recording the images of sufficient quantity for analysis. Low-cost and easily captured photographic images can replace costly radiographic procedures without causing any discomfort to the patients.

An artifıcial ıntelligence approach to automatic tooth detection and numbering in panoramic radiographs

Background

Panoramic radiography is an imaging method for displaying maxillary and mandibular teeth together with their supporting structures. Panoramic radiography is frequently used in dental imaging due to its relatively low radiation dose, short imaging time, and low burden to the patient. We verified the diagnostic performance of an artificial intelligence (AI) system based on a deep convolutional neural network method to detect and number teeth on panoramic radiographs.

Methods

The data set included 2482 anonymized panoramic radiographs from adults from the archive of Eskisehir Osmangazi University, Faculty of Dentistry, Department of Oral and Maxillofacial Radiology. A Faster R-CNN Inception v2 model was used to develop an AI algorithm (CranioCatch, Eskisehir, Turkey) to automatically detect and number teeth on panoramic radiographs. Human observation and AI methods were compared on a test data set consisting of 249 panoramic radiographs. True positive, false positive, and false negative rates were calculated for each quadrant of the jaws. The sensitivity, precision, and F-measure values were estimated using a confusion matrix.

Results

The total numbers of true positive, false positive, and false negative results were 6940, 250, and 320 for all quadrants, respectively. Consequently, the estimated sensitivity, precision, and F-measure were 0.9559, 0.9652, and 0.9606, respectively.

Conclusions

The deep convolutional neural network system was successful in detecting and numbering teeth. Clinicians can use AI systems to detect and number teeth on panoramic radiographs, which may eventually replace evaluation by human observers and support decision making.

A Novel Volume-based Cone-beam Computed Tomographic Periapical Index

INTRODUCTION

The purpose of this study was to evaluate the variations in the volume of periapical lesions scored using a cone-beam computed tomographic periapical index (CBCTPAI) and to develop a new volume-based periapical index.

METHODS

Cone-beam computed tomographic images were obtained from InteleViewer (Intelerad Medical Systems Incorporated, Montreal, Canada). Teeth with a periapical radiolucency or with a history of endodontic treatment were included in this study. Using 3-dimensional medical imaging processing software (Mimics Research; Materialise NV, Leuven, Belgium), the maximum diameter of 273 periapical lesions and their corresponding CBCTPAI score was determined. The software was then used to determine the volume of the lesions using a semiautomatic segmentation technique.

RESULTS

There was a substantial variation in the volume for CBCTPAI scores 3, 4, and 5, which was demonstrated by the variance and range, thus making it difficult to use the current CBCTPAI as a method to predict volume and treatment outcomes. A new index, the cone-beam computed tomographic periapical volume index (CBCTPAVI), was developed using partition classification analysis. The results for the new index demonstrated high levels of sensitivity, specificity, precision, and area under the curve, all at 0.90 or more, except 1 sensitivity for CBCTPAVI 1 at 0.875. Overall, the accurate classification rate was 98.169%, and the root mean square error rate was low at 0.07.

CONCLUSIONS

The proposed CBCTPAVI will allow clinicians to classify lesions based on their true 3-dimensional size, accurately assess healing of lesions, and predict treatment outcomes.

The Chairside Periodontal Diagnostic Toolkit: Past, Present, and Future

Periodontal diseases comprise a group of globally prevalent, chronic oral inflammatory conditions caused by microbial dysbiosis and the host immune response. These diseases specifically affect the tooth-supporting tissues (i.e., the periodontium) but are also known to contribute to systemic inflammation. If left untreated, periodontal diseases can ultimately progress to tooth loss, lead to compromised oral function, and negatively impact the overall quality of life. Therefore, it is important for the clinician to accurately diagnose these diseases both early and accurately chairside. Currently, the staging and grading of periodontal diseases are based on recording medical and dental histories, thorough oral examination, and multiple clinical and radiographic analyses of the periodontium. There have been numerous attempts to improve, automate, and digitize the collection of this information with varied success. Recent studies focused on the subgingival microbiome and the host immune response suggest there is an untapped potential for non-invasive oral sampling to assist clinicians in the chairside diagnosis and, potentially, prognosis. Here, we review the available toolkit available for diagnosing periodontal diseases, discuss commercially available options, and highlight the need for collaborative research initiatives and state-of-the-art technology development across disciplines to overcome the challenges of rapid periodontal disease diagnosis.

Comparative dosimetry of radiography device, MSCT device and two CBCT devices in the elbow region

The aim of the study was to estimate and to compare effective doses in the elbow region resulting from four different x-ray imaging modalities. Absorbed organ doses were measured using 11 metal oxide field effect transistor (MOSFET) dosimeters that were placed in a custom-made anthropomorphic elbow RANDO phantom. Examinations were performed using Shimadzu FH-21 HR radiography device, Siemens Sensation Open 24-slice MSCT-device, NewTom 5G CBCT device, and Planmed Verity CBCT device, and the effective doses were calculated according to ICRP 103 recommendations. The effective dose for the conventional radiographic device was 1.5 µSv. The effective dose for the NewTom 5G CBCT ranged between 2.0 and 6.7 µSv, for the Planmed Verity CBCT device 2.6 µSv and for the Siemens Sensation MSCT device 37.4 µSv. Compared with conventional 2D radiography, this study demonstrated a 1.4-4.6 fold increase in effective dose for CBCT and 25-fold dose for standard MSCT protocols. When compared with 3D CBCT protocols, the study showed a 6-19 fold increase in effective dose using a standard MSCT protocol. CBCT devices offer a feasible low-dose alternative for elbow 3D imaging when compared to MSCT.

Estimation of the radiation dose for dental spectral cone-beam CT

OBJECTIVES

The purpose of this study was to estimate the radiation dose for a dental spectral cone-beam CT (SCBCT) unit at different scanning parameters.

METHODS

Radiation dose measurements were performed for a commercially available dental SCBCT. Scans were obtained at different exposure times and fields of view (FOV), both for non-spectral (25×18 cm, 14×18 cm, 14×12 cm, 9×9 cm, 6×6 cm) and spectral modes (14×18 cm, 14×12 cm, 9×9 cm, 6×6 cm) with the tube voltage alternating between 80 and 110 kV for spectral mode, and fixed at 110 kV for non-spectral mode. An ion chamber was used for air kerma and dose area product (DAP) measurements. The effective dose was estimated based on the mAs using previously published logarithmic curves for CBCT units with a similar X-ray spectrum.

RESULTS

The adult effective dose, in non-spectral mode, was 44-269 µSv for small FOVs, 131-336 µSv for the medium FOV, and 163-476 µSv for the large FOV. In spectral mode, the estimated adult effective doses were 96-206 µSv for small, 299 µSv for medium and 372 µSv for large FOV protocols. Paediatric effective doses were estimated to be 75% higher than corresponding adult doses.

CONCLUSION

SCBCT showed comparable doses with other CBCT devices, but DAP values were generally above currently published DRLs. Spectral imaging might allow for artefact reduction at comparable dose levels, which should be assessed in further image quality studies at both a technical and diagnostic levels.

Efecto de los daños causados por el insecto escudo verde (Palomena prasina L.) en las características cualitativas de la avellana

Este estudio se realizó en 2018 para determinar el efecto del daño del insecto escudo verde (DV) en las propiedades químicas del cultivar de avellana "Tombul". La composición proximal, proteína, lípidos totales (LT), carbohidratos, relación total de cenizas (CT), vitamina E (VE), fenólicos totales, valores de energía (E), color, composición de ácidos grasos, ácidos grasos totales, oxidación de lípidos e índice de calidad nutricional se determinaron en relación con los daños causados por el insecto. Se encontró que el nivel de LT, CT, VE, E, ácidos grasos monoinsaturados (MUFA) y ácidos grasos insaturados/saturados (UFA/SFA) fue menor en los granos de DV que en los granos buenos (GB). Aunque los granos de DV tienen niveles más altos de yodo, acidez, grasa libre y peróxidos, tienen niveles más bajos de la relación ácido oleico/linoleico y de los valores de rancimat. Además, los granos de DV tienen una relación más baja PUFA/SFA y de hipocolesterolémica/hipercolesterolémica, pero tienen valores de índice de aterogenicidad y trombogenicidad más altos.

Dentistry 4.0 technologies applications for dentistry during COVID-19 pandemic

The term, Dentistry 4.0, coincides with Industry 4.0, in which the traditional methods of manufacturing and information are made more precise to enhance process efficiency by using automation and advanced computer technologies. The main of this paper is to discuss the major potential of Dentistry 4.0 technologies in the field of dentistry during Coronavirus (COVID-19) Pandemic. Thereon, Dentistry 4.0 is advancing on its way with the use of advanced technologies in dentistry. Dental healthcare makes an essential part of the overall health of the masses. New technological advancements are essential to make the dentist work quicker, patient comfortable, and process reliable. So, we introduced the concept of Dentistry 4.0 to improve efficiency and impart innovation in dentistry during this pandemic. This paper briefs about the Dentistry 4.0 technologies helpful for the COVID-19 pandemic. Further discusses various issues and challenges in implementing Dentistry 4.0 for dentistry during the COVID-19 pandemic. Finally, the paper identifies and discussed fifteen significant applications of Dentistry 4.0 technologies for dentistry during the COVID-19 pandemic. With the onset of the pandemic, globally, the healthcare sector is taking initiatives to strengthen affordable and high-speed data connectivity. This up-gradation and investment will also help dentists to access patients' data from smaller towns or villages using Dentistry 4.0 technologies. Thus, globally there is the onset of the fourth dentistry revolution, and we understand that this will change the trend of dentistry during and post-COVID-19 Pandemic. Dentistry 4.0 technologies are helpful during the COVID-19 pandemic to create teledentistry, virtual clinical practice and connect all dental devices to improve health conditions. This approach is to help progress towards the integrated capabilities, patient-centric remedies with predicted results in an easier way than the traditional way of the health care industry.

[Use of skeletal-related diagnostic methods in articles published from 2018 to 2020 in four major orthodontics journals]

Objective

To determine the skeletal-related diagnostic methods most commonly used according to the four most important orthodontics journals in the period from 2018 to 2020.

Methods

A review of the data available regarding the diagnostic procedures most frequently used to determine skeletal relationships in the four most important orthodontics journals from 2018 to 2020. Article review was performed using SCIMAGO 2018, which provides a series of parameters ranking the importance of the impact of publications and journals. We made a synopsis of the information analyzed to establish a correlation and compare sources, and critically examined the articles collected on the subject of interest. An online bibliographic search of databases including mainly Medline was carried out, followed by evaluation and selection of the bibliography, organized according to the significance and nature of the study.

Results

The four journals included in the bibliographic search were: AJODO, AO, EJO and KJO. The A point-Nasion-B point (ANB) method was used in 92.2% of the articles published in AJODO, and 7.8% did not describe the method used. Twenty-three articles in the AO journal were evaluated, all of which referred to the use of ANB as the method used. Finally, 16 and 11 articles from the EJO and KJO journals, respectively, were evaluated, with 93.8% and 95%, respectively of the articles using ANB as the method of choice for determining skeletal relationships.

Conclusion

The method of choice for skeletal-related diagnostics is ANB, although this widely known method presents a risk of geometric effect.

Clinical and Cone-Beam Computed Tomography Features of Orthokeratinized Odontogenic Cysts and Odontogenic Keratocysts in the Mandible

PURPOSE

The aim of the study was to compare the clinical and cone-beam computed tomography features of orthokeratinized odontogenic cysts (OOCs) and odontogenic keratocysts (OKCs) and to fully understand features of these 2 odontogenic cysts.

MATERIALS AND METHODS

This retrospective cross-sectional study included patients with mandibular OOCs and OKCs. The predictor variables included age at the time of diagnosis, sex, anatomical location of the cysts, lesion size, cortical bone expansion rate, and presence of cortical bone destruction, impacted tooth, tooth displacement, and root resorption. The outcome variable was the type of cystic lesion. A 1-way analysis of variance test was used to analyze the differences among the cases of OOCs and OKCs. The specificity and sensitivity of the radiological features were calculated to differentiate OOCs from OKCs.

RESULT

The sample was composed of 12 patients with OOCs and 36 patients with OKCs. The mean ages of the patients with OOCs (30.50 ± 6.14 years) and OKCs (38.39 ± 19.44 years) were concentrated in the third decade. The cystic lesions occurring in areas II and III accounted for 66.67 and 52.78% of the OOC and OKC cases, respectively. The cortical bone expansion rate of the OOC was larger than that of the unilocular OKC (OOC, 2.20 ± 1.05; OKC, 1.48 ± 0.50; P < .05). The specificity and sensitivity of unilocular or multiocular cysts to differentiate OOC from OKC were 100%, 42%, 95% confidence interval of 0.1479 to 0.3892 (P < .05) and tooth displacement were 100%, 3%, 95% confidence interval of 0.1479 to 0.3892 (P < .05).

CONCLUSIONS

The results of this study suggest clinical and radiological features of OOCs and OKCs mostly overlap, but OOC has distinctive characteristics. Most cystic lesions of OOC are unilocular cysts, rarely accompanied by tooth displacement. The cortical bone expansion rate is larger than that of unilocular cysts of OKC.

Simultaneous imaging of hard and soft biological tissues in a low-field dental MRI scanner

Magnetic Resonance Imaging (MRI) of hard biological tissues is challenging due to the fleeting lifetime and low strength of their response to resonant stimuli, especially at low magnetic fields. Consequently, the impact of MRI on some medical applications, such as dentistry, continues to be limited. Here, we present three-dimensional reconstructions of ex-vivo human teeth, as well as a rabbit head and part of a cow femur, all obtained at a field strength of 260 mT. These images are the first featuring soft and hard tissues simultaneously at sub-Tesla fields, and they have been acquired in a home-made, special-purpose, pre-medical MRI scanner designed with the goal of demonstrating dental imaging at low field settings. We encode spatial information with two pulse sequences: Pointwise-Encoding Time reduction with Radial Acquisition and a new sequence we have called Double Radial Non-Stop Spin Echo, which we find to perform better than the former. For image reconstruction we employ Algebraic Reconstruction Techniques (ART) as well as standard Fourier methods. An analysis of the resulting images shows that ART reconstructions exhibit a higher signal-to-noise ratio with a more homogeneous noise distribution.

Timing of Spheno-Occipital Synchondrosis Ossification in Children and Adolescents with Cleft Lip and Palate: A Retrospective Case-Control Study

Background: Cleft lip and palate (CLP) can affect the development of the maxilla; which may create a midfacial deficiency as well as an interference of the facial growth pattern and dentofacial esthetics. Objective: This study aimed to estimate the chronological age of complete fusion of the spheno-occipital synchondrosis (SOS) in cleft lip and palate patients and a control group; using cone beam computed tomography (CBCT) images. Methods: In this retrospective study; 125 patients were enrolled (cleft lip and palate group (n = 91); control group (n = 34)). Age comparison was made with a chi-square test; and a Kaplan–Meier analysis determined the median time to reach complete fusion of the spheno-occipital synchondrosis (p < 0.05). Results: The experimental group showed statistically significant differences in the median time for complete ossification between males and females (p = 0.019). The median time for complete ossification of the spheno-occipital synchondrosis was; for males; 15.0 years in both groups; for females; it was 14.0 years and 13.0 years in the experimental group and in the control group; respectively. Both for males and females; there were no statistically significant differences between experimental and control groups (p = 0.104). Conclusions: The present study showed no differences in the ossification of the spheno-occipital synchondrosis between individuals with and without cleft lip and/or palate.

Handheld optical coherence tomography for clinical assessment of dental plaque and gingiva

SIGNIFICANCE

Optical coherence tomography (OCT) offers high spatial resolution and contrast for imaging intraoral structures, yet few studies have investigated its clinical feasibility for dental plaque and gingiva imaging in vivo. Furthermore, the accessibility is often limited to anterior teeth due to bulky imaging systems and probes.

AIM

A custom-designed, handheld probe-based, spectral-domain OCT system with an interchangeable attachment was developed to assess dental plaque and gingival health in a clinical setting.

APPROACH

Healthy volunteers and subjects with gingivitis and sufficient plaque were recruited. The handheld OCT system was operated by trained dental hygienists to acquire images of dental plaque and gingiva at various locations and after one-week use of oral hygiene products.

RESULTS

The handheld OCT can access premolars, first molars, and lingual sides of teeth to visualize the plaque distribution. OCT intensity-based texture analysis revealed lower intensity from selected sites in subjects with gingivitis. The distribution of the dental plaque after one-week use of the oral hygiene products was compared, showing the capability of OCT as a longitudinal tracking tool.

CONCLUSIONS

OCT has a strong potential to display and assess dental plaque and gingiva in a clinical setting. Meanwhile, technological challenges remain to perform systematic longitudinal tracking and comparative analyses.

Breaking new ground in mineralized tissue: Assessing tissue quality in clinical and laboratory studies

Mineralized tissues, such as bone and teeth, have extraordinary mechanical properties of both strength and toughness. This mechanical behavior originates from deformation and fracture resistance mechanisms in their multi-scale structure. The term quality describes the matrix composition, multi-scale structure, remodeling dynamics, water content, and micro-damage accumulation in the tissue. Aging and disease result in changes in the tissue quality that may reduce strength and toughness and lead to elevated fracture risk. Therefore, the capability to measure the quality of mineralized tissues provides critical information on disease progression and mechanical integrity. Here, we provide an overview of clinical and laboratory-based techniques to assess the quality of mineralized tissues in health and disease. Current techniques used in clinical settings include radiography-based (radiographs, dual energy x-ray absorptiometry, EOS) and x-ray tomography-based methods (high resolution peripheral quantitative computed tomography, cone beam computed tomography). In the laboratory, tissue quality can be investigated in ex vivo samples with x-ray imaging (micro and nano-computed tomography, x-ray microscopy), electron microscopy (scanning/transmission electron imaging (SEM/STEM), backscattered scanning electron microscopy, Focused Ion Beam-SEM), light microscopy, spectroscopy (Raman spectroscopy and Fourier transform infrared spectroscopy) and assessment of mechanical behavior (mechanical testing, fracture mechanics and reference point indentation). It is important for clinicians and basic science researchers to be aware of the techniques available in different types of research. While x-ray imaging techniques translated to the clinic have provided exceptional advancements in patient care, the future challenge will be to incorporate high-resolution laboratory-based bone quality measurements into clinical settings to broaden the depth of information available to clinicians during diagnostics, treatment and management of mineralized tissue pathologies.

Estimating bone mineral density using MRI in medicine and dentistry: a literature review

OBJECTIVES

Studies performed in the medical area have shown that an indirect diagnosis of bone mineral density (BMD) is feasible by assessing the amount of bone marrow fat with non-ionizing magnetic resonance imaging (MRI). In dentistry, radiographic methods are still the most used for alveolar bone diagnosis. The present literature review aimed at addressing the role of MRI in assessing BMD in medicine and dentistry.

METHODS

MEDLINE and EMBASE databases were searched for articles published up to 2019.

RESULTS

A total of 428 potentially eligible papers were screened. Of these, 397 were excluded after title, abstract and keyword assessment, yielding 31 papers that potentially met the inclusion criteria. Eleven studies were then excluded because their full texts did not discuss the role of MRI in the indirect diagnosis of BMD. As a result, a total of 20 studies were finally identified as eligible for inclusion in this literature review. Most studies found satisfactory accuracy of MRI for indirectly assessing BMD by quantifying bone mineral fat (BMF). However, only one of these studies was on dentistry.

CONCLUSION

Within the limitations of this study, the present findings suggest that MRI is accurate to indirectly estimate bone density by assessing BMF, and could be clinically relevant during dental treatment planning.

Comparative Evaluation of Digitization of Diagnostic Dental Cast (Plaster) Models Using Different Scanning Technologies

Rapidly developing digital dental technologies have substantially simplified the documentation of plaster dental models. The large variety of available scanners with varying degrees of accuracy and cost, however, makes the purchase decision difficult. This study assessed the digitization accuracy of a cone-beam computed tomography (CBCT) and an intraoral scanner (IOS), as compared to a desktop optical scanner (OS). Ten plaster dental models were digitized three times (n = 30) with each scanner. The generated STL files were cross-compared, and the RMS values were calculated. Conclusions were drawn about the accuracy with respect to precision and trueness levels. The precision of the CBCT scanner was similar to the desktop OS reference, which both had a median deviation of 0.04 mm. The IOS had statistically significantly higher deviation compared to the reference OS, with a median deviation of 0.18 mm. The trueness values of the CBCT was also better than that of IOS—median differences of 0.14 and 0.17 mm, respectively. We conclude that the tested CBCT scanner is a highly accurate and user-friendly scanner for model digitization, and therefore a valuable alternative to the OS. The tested IOS was generally of lower accuracy, but it can still be used for plaster dental model digitization.

Diagnostic Performance of ICDAS II, FluoreCam and Ultrasound for Flat Surface Caries with Different Depths

The use of ultrasound for the diagnosis of natural caries lesions with different depths on flat surfaces of permanent molar teeth was studied. A total of 200 freshly extracted permanent molar teeth with natural caries lesions were included. After evaluation with International Caries and Detection Assessment System II (ICDAS II), mineral loss and lesions in the teeth were detected with a fluorescence device, FluoreCam and lesion depths were measured using ultrasound. The teeth were sectioned and examined histologically using a microscope. The intraclass correlation coefficient was 0.97 for the ultrasound system, 0.65 for the ICDAS II classification and 0.59 for FluoreCam (p < 0.001 for all). With an increase in ICDAS II scores, mean ultrasound values, FluoreCam-Size and microscope measurements increased numerically, while FluoreCam-Intensity and FluoreCam-Impact measurements inversely decreased (p < 0.001). There was a high level of agreement between histologic diagnosis and ultrasound. Ultrasound and FluoreCam can be used to detect enamel caries on flat surfaces.

Evaluation of canine teeth crown reduction technique in macaques

Background

The reduction of canine teeth in adult males in whom permanent canine teeth eruption occurs should be considered due to the safety of humans or other monkeys. The objective of this study was to evaluate the complications of canine teeth reduction in macaques. Case presentation: Canine teeth reductions were performed in 8 rhesus and 2 cynomolgus macaques. Complications related to canine teeth reduction were evaluated at one to three week intervals during the experimental period by gross examination, CBC, and monitoring of appetite. One monkey showed a fistula due to periapical abscess and neutrophilia more than 2 years after canine teeth reduction, and extraction of the diseased canine tooth was performed; the other 9 monkeys showed no complications during the observation period. This report shows the effectiveness of canine teeth reduction with few complications.

Conclusion

Canine teeth reduction in male macaques is an acceptable procedure for reducing the severity of injury to humans or other monkeys.

Platelet-Rich Fibrin for Hard- and Soft-Tissue Healing in Mandibular Third Molar Extraction Socket

Background:

Successful management of patients reporting with extreme sensitivity in second molar after surgical extraction of deeply impacted mandibular third molar poses a big challenge to oral surgeons and periodontists worldwide. A variety of grafts, barrier membranes, and guided tissue regeneration techniques have been used postsurgically for soft- and hard-tissue formation. In the current study, platelet-rich fibrin (PRF), a second-generation platelet aggregate, was assessed for its effectiveness in promoting hard- and soft-tissue healing.

Objective:

The aim of the study was to evaluate the efficacy of PRF in hard- and soft-tissue healing after extraction of mandibular third molar.

Materials and Methods:

Bilateral surgical disimpaction of mandibular third molar was done on 25 patients. In every patient, randomly allocated test side received PRF and the other side acted as control. Pain, edema, tenderness, sensitivity, Sulcus Bleeding Index (SBI), Plaque Index, clinical attachment level (CAL), probing depth, and bone height were measured at different intervals for a maximum period of 6 months.

Results:

There was a statistically significant improvement in patients' signs and symptoms of pain, tenderness, edema, and sensitivity with the use of PRF. A statistically significant improvement was seen in SBI, Plaque Index, and probing depths, while CALs and bone height were not influenced by PRF use.

Conclusion:

PRF is a very viable and useful biomaterial for soft-tissue healing and relieving patient symptoms, however, it does not help in hard-tissue healing with respect to cortical bone.

Optimal imaging windows of indocyanine green-assisted near-infrared dental imaging with rat model and its comparison to X-ray imaging

In this study, we used rat animal model to compare the efficiency of indocyanine green (ICG)-assisted dental near-infrared fluorescence imaging with X-ray imaging, and we optimized the imaging window for both unerupted and erupted molars. The results show that the morphology of the dental structures was observed clearly from ICG-assisted dental images (especially through the endoscope). A better image contrast was easily acquired at the short imaging windows (<10 minutes) for unerupted and erupted molars. For unerupted molars, there is another optimized imaging window (48-96 hours) with a prominent glow-in-the-dark effect: only the molars remain bright. This study also revealed that the laser ablation of dental follicles can disrupt the molar development, and our method is able to efficiently detect laser-treated molars and acquire the precise morphology. Thus, ICG-assisted dental imaging has the potential to be a safer and more efficient imaging modality for the real-time diagnosis of dental diseases.

Diagnostic accuracy of panoramic radiography and ultrasonography in detecting periapical lesions using periapical radiography as a gold standard

OBJECTIVES

The purpose of this study was to compare the accuracy of imaging techniques in diagnosing periapical lesions.

METHODS

Imaging records of 80 patients (51 females, 29 males, aged between 14 and 75 years) including periapical and panoramic radiographs and ultrasonographic images were selected from databases of Selcuk University Dentistry Faculty. Periapical radiographs were accepted as gold-standard and 160 anterior maxillary and mandibular teeth with or without periapical lesion were included to the study. Three specialist observers (dental radiologists) evaluated the presence and appearance of periapical lesions on panoramic radiograph and ultrasonographic images.Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic value of panoramic radiographs and ultrasonography were determined.

RESULTS

Sensitivity was 0.80 and 0.77 for ultrasonographic images and panoramic radiographs, respectively which shows that periapical lesion was correctly detected in 80% of the cases with ultrasound and in 77% of the cases with panoramic radiography. Specificity values were determined as 0.97 for ultrasound and 0.95 for panoramic radiography. Overall diagnostic accuracy was 0.86 and 0.84 for ultrasound and panoramic radiography, respectively.

CONCLUSIONS

Periapical and panoramic radiographs are commonly used to visualize periapical lesions. Besides, ultrasonography is an alternative method to digital radiographic techniques in the diagnosis of anterior teeth with periapical lesions.

The correlation between the three-dimensional radiolucency area around the crown of impacted maxillary canines and dentigerous cysts

This study aimed to reveal the correlation between the radiolucency area around the crown of impacted maxillary canines and dentigerous cysts using cone beam CT (CBCT). CBCT data were obtained from patients with impacted maxillary canines. Three points of five areas (tooth cusp area and buccal, lingual, mesial and distal areas of the crown) were randomly selected, and the distance between the point and the surrounding hard tissue was measured respectively. The mean values were recorded as the radiolucency area. These results were compared with the occurrence of dentigerous cysts during surgery. 58 patients with 76 impacted maxillary canines were included. 14 of the 76 impacted canines were accompanied by cysts (18.42%). With the increase in the thickness of the radiolucency area, the incidence of cysts was significantly increased (p < 0.05). No cysts were found in the compacted canines with 0-1 mm thickness of the radiolucency area. The highest incidence (71.43%) was observed in canines with 3-4 mm thickness of the radiolucency area. This study found that the thickness of the radiolucency area around the crown of the maxillary impacted canine was closely related to the occurrence of dentigerous cysts. CBCT can be used to estimate the occurrence possibility of dentigerous cyst and guide surgical operations.

Nanodrug Delivery Systems for the Treatment of Ovarian Cancer

Despite advances achieved in medicine, chemotherapeutics still has detrimental side effects with ovarian cancer (OC), accounting for numerous deaths among females. The provision of safe, early detection and active treatment of OC remains a challenge, in spite of improvements in new antineoplastic discovery. Nanosystems have shown remarkable progress with impact in diagnosis and chemotherapy of various cancers, due to their ideal size; improved drug encapsulation within its interior core; potential to minimize drug degradation; improve in vivo drug release kinetics; and prolong blood circulation times. However, nanodrug delivery systems have few limitations regarding its accuracy of tumour targeting and the ability to provide sustained drug release. Hence, a cogent and strategic approach has focused on nanosystem functionalization with antibody-based ligands to selectively enhance cellular uptake of antineoplastics. Antibody functionalized nanosystems are (advanced) synthetic candidates, with a broad range of efficiency in specific tumour targeting, whilst leaving normal cells unaffected. This article comprehensively reviews the present status of nanosystems, with particular emphasis on nanomicelles for molecular diagnosis and treatment of OC. In addition, biomarkers of nanosystems provide important prospects as chemotherapeutic strategies to upsurge the survival rate of patients with OC.

Periodontal evaluation using a non-invasive imaging method (ultrasonography)

The periodontal disease and gingival bleeding are highly prevalent in the adult population worldwide. The World Health Organization (WHO) data shows that 90–100% of the 34-year-old adults present gingival inflammation. Therefore, an investigation method is required to allow the assessment of the periodontal disease as well as the monitoring of the evolution of the gingival inflammation after periodontal treatments. Non-invasive and operator-independent methods for periodontal examination are necessary for diagnosing and monitoring the periodontal disease. The periodontal ultrasonography is a reliable technique for visualizing the anatomical elements which are necessary to diagnose the periodontal status. Using this imaging technique the dentino-enamel junction, the cortical bone, the radicular surface from the crown to the alveolar bone, the gingival tissue can be seen without interfering with those elements during the examination. Also, calculus visualization is possible before and after scaling in order to evaluate the quality of the treatment.

Using 2D ultrasonography is not feasible in dental practice as it requires extensive experience and is also time consuming. The reproducibility of the 2D slices is very difficult in order to have the possibility to compare different investigations efficiently. 3D reconstructions of the periodontal tissue can be a very good alternative to eliminate the operator dependence.

Ultrasonography allows the practitioner to visualize the anatomic elements involved in making a periodontal diagnosis. It also allows tracking of subsequent changes. This method is not commonly used for periodontal examination and further studies are required. Previous studies show that ultrasonography can be a reliable non-invasive method to diagnose and monitor the periodontal disease.

Trueness of CAD/CAM digitization with a desktop scanner - an in vitro study

BACKGROUND

Desktop scanners are devices for digitization of conventional impressions or gypsum casts by indirect Computer-Aided Design/Computer-Assisted Manufacturing (CAD/CAM) in dentistry. The purpose of this in vitro study was: 1, to investigate whether virtual models produced by the extraoral scanner have the same trueness as sectioned casts; and 2, to assess if digitization with an extraoral scanner influences the surface information.

METHODS

A polimethyl-methacrilic acid (PMMA) cast and a reference scanner (TwoCam 3D, SCAN technology A/S, Ringsted, Denmark; field of view 200 mm, resolution 0.1 mm ± 0.025 mm) were used to create the reference data in standard tessellation format (STL). According to the extraoral CAD/CAM digitization steps, impressions, mastercasts, and sectioned casts were made, and STL files were generated with the reference scanner. The pivotal point of the study was to digitalize these sectioned casts with the extraoral scanner (Straumann CARES Scan CS2 Visual 8.0 software, InstitutStraumann AG, Basel, Switzerland) and STL files were exported. Virtual caliper measurements were performed. Absolute deviations were compared using multilevel mixed-effects linear regression. Relative distortions were calculated with mean absolute errors and reference values.

RESULTS

Differences were observed in measurements of tooth sizes. All four prepared teeth were affected. No relationship was observed in relative deviations. Absolute differences between all the indirect digitization steps considering arch distances were: impressions, - 0.004 mm; mastercasts, 0.136 mm; sectioned casts, - 0.028 mm; and extraoral scanner, - 0.089 mm. Prepared dies on the virtual casts (extraoral scanner) were closer to each other than those on the sectioned gypsum casts. Relative deviation calculations revealed no relationship with the position of the dies in the arch.

CONCLUSION

The trueness of the virtual models generated by the extraoral scanner system used in this study was different from the dimensions of the sectioned casts. The digitization of gypsum casts changes both the dimensions of dies and the distances between the dies. The virtual casts had smaller distances than any distances measured at previous steps. Either bigger dies or longer distances did not result in greater distortions. We cannot, however, generalize our results to all scanners available on the market, because they might give different results.

Towards AR-assisted visualisation and guidance for imaging of dental decay

Untreated dental decay is the most prevalent dental problem in the world, affecting up to 2.4 billion people and leading to a significant economic and social burden. Early detection can greatly mitigate irreversible effects of dental decay, avoiding the need for expensive restorative treatment that forever disrupts the enamel protective layer of teeth. However, two key challenges exist that make early decay management difficult: unreliable detection and lack of quantitative monitoring during treatment. New optically based imaging through the enamel provides the dentist a safe means to detect, locate, and monitor the healing process. This work explores the use of an augmented reality (AR) headset to improve the workflow of early decay therapy and monitoring. The proposed workflow includes two novel AR-enabled features: (i) in situ visualisation of pre-operative optically based dental images and (ii) augmented guidance for repetitive imaging during therapy monitoring. The workflow is designed to minimise distraction, mitigate hand-eye coordination problems, and help guide monitoring of early decay during therapy in both clinical and mobile environments. The results from quantitative evaluations as well as a formative qualitative user study uncover the potentials of the proposed system and indicate that AR can serve as a promising tool in tooth decay management.

Method validation to assess in vivo cellular and subcellular changes in buccal mucosa cells and saliva following CBCT examinations

OBJECTIVES

Cone-beam CT (CBCT) is a medical imaging technique used in dental medicine. However, there are no conclusive data available indicating that exposure to X-ray doses used by CBCT are harmless. We aim, for the first time, to characterize the potential age-dependent cellular and subcellular effects related to exposure to CBCT imaging. Current objective is to describe and validate the protocol for characterization of cellular and subcellular changes after diagnostic CBCT.

METHODS

Development and validation of a dedicated two-part protocol: 1) assessing DNA double strand breaks (DSBs) in buccal mucosal (BM) cells and 2) oxidative stress measurements in saliva samples. BM cells and saliva samples are collected prior to and 0.5 h after CBCT examination. BM cells are also collected 24 h after CBCT examination. DNA DSBs are monitored in BM cells via immunocytochemical staining for γH2AX and 53BP1. 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) and total antioxidant capacity are measured in saliva to assess oxidative damage.

RESULTS

Validation experiments show that sufficient BM cells are collected (97.1 ± 1.4 %) and that γH2AX/53BP1 foci can be detected before and after CBCT examination. Collection and analysis of saliva samples, either sham exposed or exposed to IR, show that changes in 8-oxo-dG and total antioxidant capacity can be detected in saliva samples after CBCT examination.

CONCLUSION

The DIMITRA Research Group presents a two-part protocol to analyze potential age-related biological differences following CBCT examinations. This protocol was validated for collecting BM cells and saliva and for analyzing these samples for DNA DSBs and oxidative stress markers, respectively.

Assessment of the Capability of Bone Density Contrast Dissociation in Cone Beam Computed Tomography Compared to Digital Periapical Radiography by Using a Phantom

STATEMENT OF THE PROBLEM

Assessment of bone density changes plays an important role in diagnosis, treatment, and follow-up procedures. The feasibility of cone-beam computed tomography (CBCT) for assessment of bone density changes is still controversial.

PURPOSE

The aim of this study was to investigate the capability of bone density contrast dissociation of CBCT compared to digital periapical radiography.

MATERIALS AND METHOD

In this in vitro, experimental study, we designed radiographic phantom for bone density simulation. The phantom was a polytetrafluoroethylene rectangular cube with five-chambers. Five micro-tubes (2 mL) containing different concentrations of dipotassium phosphate (K₂HPO₄) were placed within these chambers. Different concentrations of K₂HPO₄ were scanned by CBCT; the mean voxel value of each micro-tube was measured and compared with the concentration of K₂HPO₄ that represented bone density.

RESULTS

CBCT results showed that there were no significant correlations between 300 mg/mL and lower concentrations of K₂HPO₄ and CBCT voxel values (P≤0.52) but there was a significant correlation between concentrations of K₂HPO₄ higher than 300 mg/mL and CBCT voxel values (p< 0.001).

CONCLUSION

CBCT is a reliable method for the assessment of bone density changes in the high range of bone density but it is not reliable for such assessment in the lower range of bone density. Digital periapical imaging method may not be applied for the assessment of bone density, whereas in higher densities, the employment of CBCT seems to be feasible.

Method for Automated Selection of the Trabecular Area in Digital Periapical Radiographic Images Using Morphological Operations

Objectives

The aim of this study is to propose a method that automatically select the trabecular bone area in digital periapical radiographic images using a sequence of morphological operations.

Methods

The study involved 50 digital periapical radiographic images of women aged from 36 to 58 years old. The proposed method consists of three stages: teeth detection, trabecular identification, and validation. A series of morphological operations—top-hat and bottom-hat filtering, automatic thresholding, closing, labeling, global thresholding, and image subtraction—are performed to automatically obtain the trabecular bone area in images. For validation, the results of the proposed method were compared with those of two dentists pixel by pixel. Three parameters were used in the validation: trabecular area, percentage of agreed area, and percentage of disagreed area.

Results

The proposed method obtains the trabecular bone area in a polygon. The obtained trabecular bone area is usually larger than that of previous studies, but is usually smaller than the dentists'. On average over all images, the trabecular area produced by the proposed method is 5.83% smaller than that identified by dentists. Furthermore, the average percentage of agreed area and the average percentage of disagreed area of the proposed method against the dentists' results were 75.22% and 8.75%, respectively.

Conclusions

The shape of the trabecular bone area produced by the proposed method is similar and closer to that identified by dentists. The method, which consists of only simple morphological operations on digital periapical radiographic images, can be considered for selecting the trabecular bone area automatically.

The Prevalence and Correlation of Carotid Artery Calcifications and Dental Pulp Stones in a Saudi Arabian Population

Background: This study sought to determine the prevalence of carotid artery calcifications (CACs) and pulp stones detected on panoramic radiographs (PRs) and ascertain their correlation. Methods: A total of 2013 digital PRs were retrospectively retrieved and thoroughly examined to determine the prevalence of CACs and pulp stones, their correlation with patient age and gender, and the relationship between the presence of pulps stones and radiographically detectable CACs. Results: The prevalence of CACs on PRs was 2.0%; the prevalence of pulp stones was 4.6%. There was no statistical relationship between pulp stones and CACs (p = 0.714). Older patients exhibited a significantly higher prevalence of CACs than younger patients (p < 0.001); pulp stones were statistically more prevalent in younger patients than older patients (p = 0.001). There were no significant differences between male and females in terms of the prevalence of either CACs or pulp stones (p = 0.087 and p = 0.278, respectively). Conclusions: Dentists should be trained to detect CACs on PRs belonging to patients older than 40 to exclude the presence of CACs. Moreover, pulp stones do not function as a diagnostic marker for CACs.

Age estimation using pulp/enamel volume ratio of impacted mandibular third molars measured on CBCT images in a northern Chinese population

The present study aims to evaluate the relation between chronological age and the ratio of pulp volume (PV) to enamel volume (EV) of impacted mandibular third molars (IMTMs) by using cone-beam computed tomography (CBCT) images and an improved 3D image segmentation technique. A sample of CBCT images of IMTM was collected from 414 northern Chinese subjects (214 male and 200 female clinical patients) ranging in age from 20 to 65 years. The GrowCut effect image segmentation (GCEIS) module algorithm was used to calculate the PV and EV from CBCT images. The total sample was divided into a training group and validation group in a ratio of 7 to 3. The PV/EV ratio (PEr) in the training sample was used to develop a mathematical formula for age estimation as follows: age = - 5.817-21.726 × Ln PEr (p < 0.0001) (Ln, natural logarithm). The mean absolute error (MAE) and root mean square error (RMSE) were used to determine the precision and accuracy of the mathematical formula in the validation group and all samples. The MAEs in the male, female, and pooled gender samples were 9.223, 7.722, and 8.41, respectively, and the RMSEs in the male, female, and pooled gender samples were 10.76, 9.58, and 9.986, respectively. The precise and accurate results indicate that the PEr of IMTM in CBCT images is a potential index for dental age estimation and is possible to be used in forensic medicine.

Near-infrared multispectral endoscopic imaging of deep artificial interproximal lesions in extracted teeth

BACKGROUND AND OBJECTIVE

A safer alternative method to radiographic imaging is needed. We present a multispectral near-infrared scanning fiber endoscope (nirSFE) for dental imaging which is designed to be the smallest imaging probe with near-infrared (NIR) imaging (1200-2000 nm).

MATERIALS AND METHODS

The prototype nirSFE is designed for wide-field forward viewing of scanned laser illumination at 1310, 1460, or 1550 nm. Artificial lesions with varying sizes and locations were prepared on proximal surfaces of extracted human teeth to examine capability and limitation of this new dental imaging modality. Nineteen artificial interproximal lesions and several natural occlusal lesions on extracted teeth were imaged with nirSFE, OCT, and microCT.

RESULTS

Our nirSFE system has a flexible shaft as well as a probe tip with diameter of 1.6 mm and a rigid length of 9 mm. The small form factor and multispectral NIR imaging capability enables multiple viewing angles and reliable detection of lesions that can extend into the dentin. Among nineteen artificial interproximal lesions, the nirSFE reflectance imaging operating at 1460-nm and OCT operating at 1310-nm scanned illumination exhibited high sensitivity for interproximal lesions that were closer to occlusal surface. Diagnosis from a non-blinded trained user by looking at real-time occlusal-side nirSFE videos indicate true positive rate of 78.9%. There were no false positives.

CONCLUSIONS

This study demonstrates that nirSFE may be used for detecting occlusal lesions and interproximal lesions located less than 4 mm under the occlusal surface. Major advantages of this imaging system include multiple viewing angles due to flexibility and small form factor, as well as the ability to capture real-time video. The multispectral nirSFE has the potential to be employed as a low-cost dental camera for detecting dental lesions without exposure to ionizing radiation. Lasers Surg. Med. 51:459-465, 2019. © 2019 Wiley Periodicals, Inc.

Clinical and radiographic evaluation of Biodentine and Mineral Trioxide Aggregate in revascularization of non-vital immature permanent anterior teeth (randomized clinical study)

OBJECTIVE

To asses clinically and radiographically the effect of using two types of coronal plug materials in revascularization of non-vital immature teeth.

METHODS

A total of 26 necrotic immature permanent anterior teeth were enrolled for pulp revascularization using a double antibiotic mix for root canal disinfection. They were randomly divided into the following based on coronal plug materials used: Biodentine (Group I) and white Mineral Trioxide Aggregate (Group II; n = 13). Clinical and radiographic assessments were performed after 3, 6, 9, and 12 months.

RESULTS

When comparing the overall clinical successes and percentage of increase in root length between the two groups, there was no statistically significant difference (P > 0.05). There was a significant difference in the distribution of discoloration between the two groups. One case was reported in Group I, and seven cases were reported in Group II (P = 0.01).

CONCLUSIONS

Both Biodentine and Mineral Trioxide Aggregate were successful clinically regarding the resolution of signs and symptoms associated with the necrotic teeth.

Indocyanine-green-assisted near-infrared dental imaging - the feasibility of in vivo imaging and the optimization of imaging conditions

X-ray-based imaging, including computed tomography, plays a crucial role in the diagnosis and surgery of impacted teeth that affects over 25% of the human population. But the greatest disadvantage of this technique is ionizing radiation risk to the patients. Here we describe a completely ionizing-radiation-free in vivo near-infrared (NIR) fluoresence dental imaging with indocyanine green (ICG) agent that has rarely been applied in dental imaging. Our method can acquire dental structure images within a short period (only 10 minutes after injection) without ionizing radiation risk. NIR enables the observation of dental structures that are not distinguishable under visible conditions. At prolonged 72 hours, only molar regions remained highlighted; the contrast between molar regions and surrounding tissues was prominent; this is particularly useful for in vivo dental imaging. Using the quantitative spectral analysis, we found the peak wavelengths of ICG fluorescence shifted along with the injection time: the peak wavelength shifted 8 nm (from 819 nm to 811 nm) in 0~72 hours. The injection methods of tail vein v.s. intradermal injections caused ~3 nm shift. ICG-assisted NIR fluorescence imaging can serve as a useful tool for in vivo real-time diagnosis in dental clinics and surgeries without ionizing radiation risk.