Detecting white spot lesions on post-orthodontic oral photographs using deep learning based on the YOLOv5x algorithm: a pilot study.

BACKGROUND: Deep learning model trained on a large image dataset, can be used to detect and discriminate targets with similar but not identical appearances. The aim of this study is to evaluate the post-training performance of the CNN-based YOLOv5x algorithm in the detection of white spot lesions in post-orthodontic oral photographs using the limited data available and to make a preliminary study for fully automated models that can be clinically integrated in the future. METHODS: A total of 435 images in JPG format were uploaded into the CranioCatch labeling software and labeled white spot lesions. The labeled images were resized to 640 × 320 while maintaining their aspect ratio before model training. The labeled images were randomly divided into three groups (Training:349 images (1589 labels), Validation:43 images (181 labels), Test:43 images (215 labels)). YOLOv5x algorithm was used to perform deep learning. The segmentation performance of the tested model was visualized and analyzed using ROC analysis and a confusion matrix. True Positive (TP), False Positive (FP), and False Negative (FN) values were determined. RESULTS: Among the test group images, there were 133 TPs, 36 FPs, and 82 FNs. The model's performance metrics include precision, recall, and F1 score values of detecting white spot lesions were 0.786, 0.618, and 0.692. The AUC value obtained from the ROC analysis was 0.712. The mAP value obtained from the Precision-Recall curve graph was 0.425. CONCLUSIONS: The model's accuracy and sensitivity in detecting white spot lesions remained lower than expected for practical application, but is a promising and acceptable detection rate compared to previous study. The current study provides a preliminary insight to further improved by increasing the dataset for training, and applying modifications to the deep learning algorithm. CLINICAL REVELANCE: Deep learning systems can help clinicians to distinguish white spot lesions that may be missed during visual inspection.

Comparative Evaluation of Various Lens and Ring Flash Combination for Intraoral Photography.

BACKGROUND: Extraoral and intraoral dental photographs serve as preoperative records and document the entire treatment. Correctly composed orthodontic photographs are crucial for remote diagnosis and may serve as a bulwark against medicolegal challenges. MATERIALS AND METHODS: In this prospective study, intraoral frontal photographs of patients with ideal occlusion were taken using two types of lenses (EF-S 18-55 mm f/3.5-5.6 IS STM lens (Canon, Tokyo, JP), SP 90 mm F/2.8 MACRO VC lens (Model F017 Tamron, NY, USA)) and two different ring flash systems (Meike FC-100 Macro Ring LED Light (Meike, China), Macro Ring flash Lite YN-14EX (Yongnuo digital, China)). The combination of lens and flash used was grouped into four groups. Twenty-eight intraoral photographs of patients were taken. An image quality assessment survey was distributed among two groups - 50 orthodontists and 50 other dental specialists. RESULTS: The participants were asked to assess all the intraoral images and subjectively score them on a scale of one to ten, with one being very poor and ten being excellent, considering the sharpness, color, brightness, contrast, and overall quality of the image. The general dentists rated the images taken with a 90-mm macro lens and ring flash as the best quality photographs. Images obtained using an 18-55 mm lens and ring LED received significantly lesser scores and were graded good by dentists. CONCLUSION: This combination of lens and flash may prove a valuable investment in the long-term aiding in excellent dental images for diagnosis and treatment monitoring.

Telediagnosis of dental caries: Possible or impossible? A pilot cross-sectional study.

OBJECTIVES: The aims of this study were to evaluate the effectiveness of teledentistry (based on a home intraoral imaging protocol) in detecting dental caries and to assess the accuracy of this method compared to clinical examination. METHODS: Forty-three patients were recruited for the study. Using a protocol for taking intraoral photographs at home with a smartphone proposed by the Dental School of Verona, a remote diagnosis of dental caries (TD) was performed by an experienced dentist. The same caries sites were also assessed by clinical diagnosis (CD) by a second experienced dentist. Ten photos were taken at home in five different perspectives, with and without flash, and emailed to one of the authors. The best five photos were selected for telediagnosis. The International Caries Detection and Assessment System (ICDAS II) score was used for caries diagnosis. Statistical tests were performed: Sensitivity and specificity of TD, the positive and negative predictive value of TD (PPV-NPV), and Spearman correlation to evaluate the relationship between the scores of TD and CD. RESULTS: A total of 430 photographs were submitted; TD was performed on 215 photographs and 43 patients were visited. A total of 1201 teeth were analyzed. The sensitivity of TD was 74.0, the specificity was 99.1, the PPV of TD was 91.7, and the NPV was 96.4. The Spearman correlation was 0.816, showing a very strong correlation between the values obtained with TD and CD. CONCLUSIONS: The study showed good potential for TD, which proved to be a feasible method to combine with routine caries diagnosis in daily preventive dentistry practice.

A Standardized Approach to Extra-Oral and Intra-Oral Digital Photography.

Contemporary dentistry mandates a more comprehensive and personalized analysis of each patient. Technological advances in digital photography have played vital roles in diagnostic accuracy, treatment planning, execution of therapies, and outcome evaluations, including esthetic enhancement. Digital photography also provides an excellent platform for patient education, communication, and co-management of cases with other healthcare providers. However, intra-oral photography often faces challenges such as inaccessibility of areas to be captured, different moveable vs. fixed tissues involved, contamination with saliva or blood, and differing illumination needs on various locations. Thus, a more standardized and systematic approach is proposed for intra- and extra-oral documentation via digital photography to overcome the existing technical challenges. The current work will outline the appropriate equipment specifications (camera bodies, macro lens, and flashes), positions and postures of the operator and patients, proper techniques of tissue retraction, the use of appropriate intra-oral mirrors, and the essential elements such as aperture settings (F-stop), ISO, shutter speed, and white balance. This article aims to provide all dental professionals with an approachable linear array of guidelines to produce simplified and standardized visual tools for more efficient and effective documentation.

Automated detection of posterior restorations in permanent teeth using artificial intelligence on intraoral photographs.

OBJECTIVES: Intraoral photographs might be considered the machine-readable equivalent of a clinical-based visual examination and can potentially be used to detect and categorize dental restorations. The first objective of this study was to develop a deep learning-based convolutional neural network (CNN) for automated detection and categorization of posterior composite, cement, amalgam, gold and ceramic restorations on clinical photographs. Second, this study aimed to determine the diagnostic accuracy for the developed CNN (test method) compared to that of an expert evaluation (reference standard). METHODS: The whole image set of 1761 images (483 of unrestored teeth, 570 of composite restorations, 213 of cements, 278 of amalgam restorations, 125 of gold restorations and 92 of ceramic restorations) was divided into a training set (N = 1407, 401, 447, 66, 231, 93, and 169, respectively) and a test set (N = 354, 82, 123, 26, 47, 32, and 44). The expert diagnoses served as a reference standard for cyclic training and repeated evaluation of the CNN (ResNeXt-101-32 × 8d), which was trained by using image augmentation and transfer learning. Statistical analysis included the calculation of contingency tables, areas under the receiver operating characteristic curve and saliency maps. RESULTS: After training was complete, the CNN was able to categorize restorations correctly with the following diagnostic accuracy values: 94.9% for unrestored teeth, 92.9% for composites, 98.3% for cements, 99.2% for amalgam restorations, 99.4% for gold restorations and 97.8% for ceramic restorations. CONCLUSIONS: It was possible to categorize different types of posterior restorations on intraoral photographs automatically with a good diagnostic accuracy. CLINICAL SIGNIFICANCE: Dental diagnostics might be supported by artificial intelligence-based algorithms in the future. However, further improvements are needed to increase accuracy and practicability.

Mobile photographic screening for dental caries in children: Diagnostic performance compared to unaided visual dental examination.

OBJECTIVES: This study was conducted to compare the use of intraoral photographs with the unaided visual dental examination as a means of dental caries detection in children. METHODS: Children aged 4- to 14-year-olds were visually examined at their schools. Following dental examinations, children had five photographs of their teeth taken using a smartphone camera. Four dental reviewers, who are different from those who visually examined the children, assessed intraoral photographs for dental caries. Sensitivity, specificity, and inter-rater reliability agreement were estimated to assess the diagnostic performance of the photographic method relative to the benchmark visual dental assessments. Caries prevalence was measured using dft/DFT (decayed and filled teeth) index. RESULTS: One hundred thirty-eight children (67 male and 71 female) were enrolled and had a mean age of 7.8 ± 2.1 years. The caries prevalence (dft/DFT > 0) using photographic dental assessments ranged from 30 percent to 39 percent but was not significantly different from the prevalence (42 percent) estimated with the visual dental examination (P ≥ 0.07). The sensitivity and specificity of the photographic method for detection of dental caries compared to visual dental assessments were 58-80 percent and 99.7-99.9 percent, respectively. The sensitivity for the photographic assessments was high in the primary dentition (63-82 percent) and children ≤7-year-olds (67-78 percent). The inter-rater reliability for the photographic assessment versus the benchmark ranged from substantial to almost perfect agreement (Kappa = 0.72-0.87). CONCLUSIONS: The photographic approach to dental screening, used within the framework of its limitations, yielded an acceptable diagnostic level of caries detection, particularly in younger children with primary dentition.

Dental Whitening: Self-Referred Needs versus Professional Indication

Abstract Objective: To analyze the self-reported need of patients compared to professional indications for tooth whitening. Material and Methods: Initially, 58 undergraduate students responded to a form that highlighted the question: "Do you think you need to have your teeth whitened?" Among those who answered positively to the previous question, ten individuals were photographed with their smiles. In addition, they were asked to point out, on the Vita 3D-Master scale, which color they believed their teeth had, a value that was compared to the actual color obtained by a spectrophotometer. Finally, the photographs were presented to dentists, who were asked about the indication or not of the whitening treatment. Results: Most interviewees (63.8%) self-reported the need for whitening, as well as there was a greater incidence of a positive indication among professionals (53.9%). Pearson's Chi-square test revealed a relationship between patient gender and the training course on the desire to have teeth whitened. Among the professionals, the specialty, as well as time since graduation, interfered in the indication for whitening. Conclusion: Professionals and patients share the aesthetic ideal directly related to light teeth; most patients self-perceive the color of their teeth darker than it actually is; the opinion about the color of the teeth has an extremely subjective character and varies greatly from one professional to another (AU).

A novel method quantifying caries following orthodontic treatment.

This retrospective pilot study used a newly developed evaluation tool to assess the prevalence and incidence of White Spot Lesions (WSL) before and after multibracket appliance (MB) therapy. Digital photographs of 121 adolescent patients (63 ♂, 58 ♀) with metal brackets were analyzed retrospectively before and after MB therapy. The labial surfaces of anterior teeth, canine teeth, and premolars in the upper (UJ) and lower jaws (LJ) were evaluated using the Enamel Decalcification Index (EDI) by Banks and Richmond (Eur J Orthod, 16(1):19-25, 1994, levels 0-3) and a specially developed digitally scaled graticule with concentric circles to quantify the extent of WSL (in %). The statistical data analysis was based on crosstabulations and logistic regression. Before MB, 69.4% of the patients presented at least one WSL and 97.5% after, an increase of 28.1%. Before MB, 18.4% of the tooth surfaces (TS) showed an EDI level of 1-3. After MB, 51.8% of the TS featured WSL. 18.2% of the TS showed a WSL to the extent of ≥ 20-100% before and 52.3% after MB. The incidence in the UJ (71-79%) as well as the LJ (64-76%) was highest for the first and second premolars and lowest for LJ incisors (22-35%). The probability for developing a new distal WSL is higher than developing gingival, mesial or occlusal WSL. Labial MB therapy drastically increases the risk of developing WSL. We verified a concise quantification of the extent of labial WSL with the evaluation index.

Effectiveness of 2D radiographs in detecting CBCT-based incidental findings in orthodontic patients.

Some craniofacial diseases or anatomical variations are found in radiographic images taken for other purposes. These incidental findings (IFs) can be detected in orthodontic patients, as various radiographs are required for orthodontic diagnosis. The radiographic data of 1020-orthodontic patients were interpreted to evaluate the rates of IFs in three-dimensional (3D) cone-beam-computed tomography (CBCT) with a large field of view (FOV) and investigate the effectiveness and accuracy of two-dimensional (2D) radiographs for detecting IFs compared to CBCT. Prevalence and accuracy in five areas was measured for sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). The accuracies of various 2D-radiograph were compared through a proportion test. A total of 709-cases (69.5%) of 1020-subjects showed one or more IFs in CBCT images. Nasal cavity was the most affected area. Based on the CBCT images as a gold standard, different accuracies of various 2D-radiographs were observed in each area of the findings. The highest accuracy was confirmed in soft tissue calcifications with comprehensive radiographs. For detecting nasal septum deviations, postero-anterior cephalograms were the most accurate 2D radiograph. In cases the IFs were not determined because of its ambiguity in 2D radiographs, considering them as an absence of findings increased the accuracy.

Novel methodology for measuring intraoral wear in enamel and dental restorative materials.

OBJECTIVES: To test the hypotheses that (a) the chairside/handheld dental scanner combined with a metrology software will measure clinical wear in vivo in agreement with measurements from X-ray computed microtomography and; (b) polished monolithic zirconia does not cause accelerated wear of opposing enamel. MATERIALS AND METHODS: Thirty single crowns were randomized to receive a monolithic zirconia or metal-ceramic crown. Two non-restored opposing teeth in the same quadrants were identified to serve as enamel controls. After cementation, quadrants were scanned using an intraoral dental scanner. Patients were recalled at 6-months and 1-year for re-scanning. Scanned images were compared using a metrology software to determine maximum vertical wear of teeth. The accuracy of the scanning measurements from this new method was compared with X-ray computed microtomography (micro-CT) measurements. Statistical analysis was performed using Mann-Whitney U test to determine significant differences between wear of enamel against zirconia, metal-ceramic or enamel. Linear regression analysis determined agreement between measurements obtained using intraoral scanning and micro-CT. RESULTS: Regression analysis demonstrated that there is a quantitative agreement between depth and volume measurements produced using intraoral scanning and the micro-CT methodologies. There was no significant difference between the wear of enamel against polished monolithic zirconia crowns and enamel against enamel. CONCLUSIONS: Intraoral scanning combined with a matching software can accurately quantify clinical wear to verify that monolithic zirconia exhibited comparable wear of enamel compared with metal-ceramic crowns and control enamel. Agreement between the intraoral scanner and the micro-CT was 99.8%. Clinical Trials.gov NCT02289781.

Planejamento Digital do Sorriso / Planificación digital de la sonrisa / Digital Smile Planning

RESUMO Introdução: Avanços no campo da Odontologia Estética têm proporcionado métodos cada vez mais inovadores na construção de um sorriso funcional e harmonioso. O elevado grau de exigência do paciente por detalhes e por sorrisos personalizados evidencia a necessidade do clínico em lançar mão de meios que facilitem a comunicação para o melhor entendimento de seus pacientes em relação ao tratamento proposto. Objetivo: Realizar uma revisão de literatura sobre Planejamento Digital do Sorriso em Odontologia. Métodos: Com caráter atual e integrativo, esta revisão de literatura foi realizada utilizando os descritores estética dentária, sorriso e fotografia dentária, em portugês, inglês e espanhol, obtendo 302 artigos, dos quais foram utilizados 51 artigos e 1 livro como base científica para o estudo, obedecendo os critérios de inclusão e exclusão. Análise e integração da informação: Os avanços na informática, fotografia digital e processamento de imagens, bem como a redução dos custos envolvidos, têm proporcionado que um planejamento tradicional em odontologia para tratamentos estéticos tenha evoluído para um planejamento digital, fornecendo uma visão ampla do diagnóstico, melhorando a comunicação entre paciente e equipe profissional envolvida, tornando o tratamento mais previsível, facilitando a compreensão e permitindo sua análise crítica e participação mais ativa no planejamento. Considerações finais: As técnicas utilizadas para realização do Planejamento Digital do Sorriso tornam os procedimentos mais previsíveis, melhorando a visualização e compreensão das etapas a serem realizadas. O conceito de Visagismo não apresenta embasamento científico suficiente. Aplicações de conceitos de proporção áurea na odontologia têm sido bastante estudadas, porém seu uso não é consensual por existirem outros parâmetros(AU)

RESUMEN Introducción: Avances en el campo de la Odontología Estética han proporcionado métodos cada vez más innovadores en la construcción de una sonrisa funcional y armoniosa. El alto grado de exigencia del paciente por detalles y por sonrisas personalizadas evidencia la necesidad de que el clínico use medios que faciliten la comunicación para una mejor comprensión de sus pacientes con respecto al tratamiento propuesto. Objetivo: Realizar una revisión de literatura sobre planificación digital de la sonrisa en odontología. Métodos: Esta revisión de literatura se realizó utilizando los descriptores "estética dental", "sonrisa" y "fotografía dentaria", en portugués, inglés y español. Se recuperaron un libro y 302 artículos, de los cuales, el libro y 51 artículos fueron utilizados como base científica para el estudio. Análisis e integración de la información: Los avances en la informática, fotografía digital y procesamiento de imágenes, así como la reducción de los costos involucrados, han permitido que una planificación dental tradicional en odontología para tratamientos estéticos evolucione hacia la planificación digital y proporcione una visión amplia del diagnóstico. Esto ha mejorado la comunicación entre los pacientes y los equipos de profesionales involucrados y ha hecho el tratamiento más previsible. Así se ha facilitado la comprensión del paciente, se ha permitido su análisis crítico y su participación más activa en la planificación. Consideraciones finales: Las técnicas utilizadas para realizar la planificación digital de la sonrisa hacen los procedimientos más previsibles y mejora la visualización y comprensión de cada etapa. El concepto de Visagismo no presenta un fundamento científico suficiente. Las aplicaciones de conceptos de proporción áurea en la odontología han sido bastante estudiadas, pero, por existir otros parámetros, su uso no es consensual(AU)

ABSTRACT Introduction: Advances in the field of aesthetic dentistry have provided increasingly innovative methods for building a functional and harmonious smile. The high degree of patient demand for details and for personalized smiles shows the need for clinicians to use means that facilitate communication for better understanding of their patients regarding the proposed treatment. Objective: To carry out a literature review on digital smile planning in dentistry. Methods: This literature review was performed using the descriptors estética dental [dental aesthetics], sonrisa [smile], and fotografía dental [dental photography], in Portuguese, English and Spanish. A book and 302 articles were retrieved, of which the book and 51 articles were used as scientific basis for the study. Information analysis and integration: Advances in computer science, digital photography and image processing, as well as the reduction of costs involved, have allowed traditional dental planning in dentistry for aesthetic treatments to evolve towards digital planning and to provide comprehensive diagnostic insight. This has improved communication between patients and professional teams involved and has made treatment more predictable. Thus, the patient's understanding has been facilitated, as well as is has permitted his or her critical analysis and more active participation in planning. Final considerations: The techniques used to carry out digital smile planning make the procedures more predictable and improve the visualization and understanding in each stage. The concept of visagism does not present a sufficient scientific basis. The applications of golden ratio concepts into dentistry have been extensively studied, but, due to the existence of other parameters, their use is not consensual(AU)

An Experimental Strategy for Capturing the Margins of Prepared Single Teeth with an Intraoral Scanner: A Prospective Clinical Study on 30 Patients.

Purpose: To present an experimental strategy for successfully capturing the margins of prepared single teeth with an intraoral scanner (IOS). Methods: The protocol was as follows: (1) an intraoral impression was captured with an IOS, without taking care of the visibility of the margins; (2) a partial analog impression was taken by means of a 3D-printed custom tray filled with polyvinylsiloxane light, after the removal of a retraction cord; (3) the hollow portion of the analog impression, with the preparation margins clearly visible, was scanned extraorally with the same IOS; (4) the scan of the analog impression was imported into computer-assisted-design (CAD) software, where its normals were inverted; (5) the scan with inverted normals was registered on the first intraoral scan, and replaced it; (6) the technician designed the final restoration, which was fabricated and delivered for application. The study outcomes were: (1) the marginal adaptation of the final crown; (2) the quality of interproximal contacts; and (3) the quality of occlusal contacts. Results: Thirty patients (18 males, 12 females; mean age 51.3 ± 11.6 years) were selected for this study. All these patients were restored with a monolithic translucent zirconia crown, fabricated following the aforementioned protocol. The clinical precision and the marginal adaptation of the crowns were optimal, interproximal contact points were perfect, and the only necessary adaptations were occlusal, with some minor precontacts that had to be polished. Conclusions: The present protocol seems to be compatible with the fabrication of clinically precise zirconia crowns. Further studies are needed to confirm these results.

Possible applications of reflected UV photography in forensic odontology: Food for thought.

Usually, in forensic sciences, ultraviolet (UV) light is used to induce fluorescence on many samples to identify and evaluate proofs (ex. fibers, gunshot residue, biologic fluids, pigments, inks and fingerprints) and different wavelength are used to better enhance the material characteristics. On the contrary, the potential use of absorbed and reflected UV has not been deeply investigated, especially in forensic odontology. The aim of this study is to evaluate the forensic potential of dental materials UV absorption and reflection and to investigate if different dental tissues and materials interact in different ways with UV radiation. A digital camera modified so to be UV sensible only and a modified flashlight were used to produce images of absorbed/reflected UV radiation of different dental materials. First results show the promising potentials of the technique in detecting dental composite resin materials, in enhancing image contrast between dentin and enamel, in enhancing enamel infractions and in possible age estimation future applications.

Using Standard Digital Extra-Oral Photography in Patient With Cleft Lip and Palate / Uso de Fotografía Digital Extra Oral Estandarizada en Pacientes con Fisura Labiopalatina

ABSTRACT: A standardized photographic documentation is reproducible, which facilitates the evaluation of new techniques, treatment planning, and comparison of results. Clinical photography is important to impart scientific education to health professionals, because techniques can be better understood by the listener or reader when they are well illustrated. Documentation of consistent imaging of clinical diagnosis and treatment is also essential in medical-legal cases. Highquality clinical photographs along with radiographs and other medical and dental images should become an integral part of patients' medical records. Variables such as lens selection, camera position, distance, and patient's position should be understood and controlled by healthcare personnel for acquiring accurate photographs. In the case of patients with craniofacial deformities, such as cleft lip and palate, it is important to establish the standardization of photographic records because the patients' aesthetic evaluation is a fundamental clinical indicator in the deformity analysis, besides assisting the planning of patients' multidisciplinary treatment. This article aims to assist health professionals in acquiring standardized facial photographs (front, right profile, left profile, and submental oblique view) of patients with cleft lip and palate.

RESUMEN: Una documentación fotográfica estandarizada es reproducible, lo que facilita la evaluación de nuevas técnicas, la planificación del tratamiento y la comparación de resultados. La fotografía clínica es importante para impartir educación científica a los profesionales de la salud, ya que el oyente o lector puede comprender mejor las técnicas cuando están bien ilustradas. La documentación de imágenes consistentes de diagnóstico clínico y tratamiento también es esencial en casos médico-legales. Las fotografías clínicas de alta calidad junto con las radiografías y otras imágenes médicas y dentales deben convertirse en una parte integral de los registros médicos de los pacientes. El personal de atención médica debe comprender y controlar las variables como la selección de la lente, la posición de la cámara, la distancia y la posición del paciente para obtener fotografías precisas. En el caso de pacientes con deformidades craneofaciales, como labio leporino y paladar hendido, es importante establecer la estandarización de los registros fotográficos porque la evaluación estética de los pacientes es un indicador clínico fundamental en el análisis de la deformidad, además de ayudar en la planificación del tratamiento multidisciplinario del paciente. Este artículo pretende ayudar a los profesionales de la salud a adquirir fotografías faciales estandarizadas (frente, perfil derecho, perfil izquierdo y vista oblicua submental) de pacientes con labio leporino y paladar hendido.

Dental hard tissue morphological segmentation with sparse representation-based classifier.

In the field of dental image processing and analysis, automatic segmentation results of dental hard tissue can provide a useful reference for the clinical diagnosis and treatment process. However, the segmentation accuracy is greatly affected due to the limitation of imaging conditions in the oral environment, as well as the complexity of dental hard tissue topology. To further improve the precision of dental hard tissue segmentation, a novel algorithm was presented by using the sparse representation-based classifier and mathematical morphology operations. First, the captured dental image was preprocessed to eliminate the impact of imbalance local illumination. Then, the preliminary dental hard tissue areas were calculated as the initial marker regions based on color characteristics analysis, and the sparse representation-based classifier was applied sequentially to optimize the initial marker regions combined with certain morphological operations. Finally, a modified marker-controlled watershed transform was employed to segment dental hard tissue regions on the basis of the optimized marker regions, and the final results were obtained after homogeneous region merging. The experimental results show that our method has better adaptability and robustness than existing state-of-the-art methods. Graphical abstract.

Quantification of maxillary dental midline deviation in 2D photographs: Methodology trial.

INTRODUCTION: Discrepancy of the upper dental midline to the facial midline plays an important role in smile aesthetic assessment. This study presents different reference points to quantify the deviation of upper dental midline to the facial midline in 2D frontal photographs. The aim was to find the most accurate, precise, and practical reference points to measure dental midline discrepancy in 2D photographs. METHODOLOGY: A modified headset with a protractor was developed in order to achieve photographs in nine standardised head positions. Six reference points were used to detect the facial midline in the 2D photographs (eyebrows "EB", inner-canthus of the eyes "ICE", alae of the nose "AN", columella "C", nasolabial folds "NLF", and the philtrum "PH"). The deviation of the maxillary dental midline from the facial midline was measured and compared with clinical measurements. STATISTICAL ANALYSIS: Standard deviations (SD), Root Mean Square Error (RMSE), Method of Moments' Estimator (MME), 2-way repeated measures ANOVA, and multi-level linear model were used to estimate the true errors. RESULTS: The different reference points responded significantly differently to changes in head position and all showed measurement errors, which increased with greater head rotation. Alae of the nose showed the least measurement error and the greatest precision in all head positions. CONCLUSION: The alae of the nose are the recommended reference points to identify the facial midline in order to quantify dental midline deviation from frontal photographs.

Endoscopic System Based on Intraoral Camera and Image Processing.

OBJECTIVE: In dentistry, dentists perform many treatments with a few visually magnified information. About deep area of root canals, it commonly relies on exploration carried out with the fingers of the dentist, because the root canal entrance is very small to be observed. In clinical practice, the intraoral camera and endoscopic systems are separate devices, and there are no sensors to capture both pictures of the whole tooth and those inside the root canal. Objective of this research is to combine the intraoral camera and endoscopic system facilitating to use clinical practice. METHODS: We propose an endoscopic system based on the thin image fiber, SOPROLIFE intraoral camera as an image sensor, and a new adaptor to connect the two parts. We observed resolution charts with 50, 25, 10, and 5 line pairs (LP)/mm patterns. The acquired images are processed to both remove fixed-pattern noise using robust principal component analysis and enhance contrast. RESULTS: The acquired images containing all LP/mm patterns were clear and showed higher contrast after processing. Visibility of the processed images is 1.7, 1.6, 2.2, and 1.9 times higher than that of the raw images for 50, 25, 10, and 5 LP/mm patterns, respectively. CONCLUSION: Our fabricated endoscopic system based on the SOPROLIFE intraoral camera could observe 50, 25, 10, and 5 LP/mm patterns. After image processing, the noise was reduced, and high-contrast images were obtained. SIGNIFICANCE: This system can be considered as a further step toward facilitating noninvasive and contactless systems in clinical practice.

Is it feasible to use smartphone images to perform telediagnosis of different stages of occlusal caries lesions?

The purpose of this study was to compare the performance of two different models of smartphone and a conventional camera with that of direct clinical examination in detecting caries lesions at different stages of progression in deciduous molars. The photographic equipment consisted of two smartphones (iPhone and Nexus 4) and a conventional macro camera setup. First, in the laboratory phase of the study, we compared the images of 20 exfoliated primary teeth having caries lesions at different stages. Then, in the clinical phase of the study, the images of 119 primary molars from fifteen children (3 to 6 years old) were used. All of the photographic images were taken using the previously described devices. In both groups, two examiners, blinded to the photographic equipment used, assessed the images independently on a computer screen, and classified them according to the International Caries Detection and Assessment System (ICDAS). The teeth were then examined directly by two other experienced examiners, and the consensus reached was considered the reference standard. Parameters of validity, such as percentage of correct answers, agreement with the reference standard, sensitivity, specificity and inter-examiner agreement (using the weighted kappa test) were calculated. The examiners performed similarly in both in vitro and in vivo studies. Inter-examiner reliability was approximately 0.7 for all the devices in the laboratory setting, and for the macro camera photography system in the clinical setting, but it was approximately 0.9 for the iPhone and Nexus images taken in vivo. With regard to the percentage of correct answers, the highest values were observed for sound and extensive caries lesions in both laboratory and clinical settings. The percentage of correct answers for initial and moderate lesions was particularly low in the clinical evaluation, irrespective of the camera devices used. Therefore, we concluded that photographic diagnosis using smartphone images is feasible and accurate for distinguishing sound tooth surfaces from extensive caries lesions; however, photographic images are not a good method for accurately detecting initial and moderate caries lesions.

Detection of residual resin-based orthodontic adhesive based on light-induced fluorescence.

INTRODUCTION: This study evaluated the fluorescence of orthodontic adhesives using quantitative light-induced fluorescence-digital (QLF-D) images, and compared differences in the color characteristics of the fluorescence between adhesive and the adjacent tooth with that under white-light illumination in specimens containing residual adhesive of various thicknesses. METHODS: Disc-shaped adhesive samples and samples comprising adhesive attached to extracted human teeth were prepared using Transbond XT, Blugloo, and Enlight, and they were ground to thicknesses ranging from 800 to 20 µm. Fluorescence and white-light images of the two types of specimens were taken with a QLF-D system. The color parameters for the fluorescence from the discs and the color difference (ΔE) between residual adhesive and the adjacent tooth were quantified in images using the CIE L*a*b* system. RESULTS: The fluorescence color values of the discs differed significantly among the three adhesive products (P < 0.05). The ΔE values in fluorescence (ΔEF) and white-light (ΔEW) images for all three adhesives were lower for thinner residual adhesive specimens. The thickness of the adhesive could be perceived over a range of 50-100 µm for fluorescence images and 400-800 µm for white-light images (ΔE > 3.3). ΔEF was significantly larger than ΔEW for all of the residual adhesives, Blugloo specimens thicker than 100 µm, and Transbond XT and Enlight specimens thicker than 50 µm (P < 0.05). CONCLUSIONS: Detecting and analyzing fluorescence signals can improve the ability to detect residual adhesive on a tooth and also provide thickness information.

Digital dental photography.

Photography has always been an integral part of dentistry. The journey goes back to the time when film photography was used only for documentation and referral purpose which has now evolved to digital photography. Its application in dental practice is simple, fast, and extremely useful in documenting procedures of work, education of patients, and pursuing clinical investigations, thus providing many benefits to the dentists and patients. The article describes the added benefits of digital dental photography over film photography, basic armamentarium for obtaining good photographs, and how digital dental photography is beneficial in the field of prosthodontics.