Evaluating the precision and accuracy of digital dental models with a low-cost structured light device

ABSTRACT Objective: This study evaluated the accuracy and precision of digital models acquisition using a home-built, low-cost scanning system based on the structured light method. Methods: a plaster model (PM) was scanned using the experimental device (SL) and a dental desktop scanner (DS). The teeth dimensions of PM and SL models were measured in triplicate, with a caliper and digitally, respectively. The agreement of the measurements of each model was evaluated using the intraclass correlation coefficient, and the validity between the different measurement techniques was assessed using the Bland-Altman analysis. The accuracy and precision of the models were qualitatively investigated using the mesh superposition of the SL and DS models. Results: A high intraclass correlation coefficient was observed in all models (PM=0.964; SL1=0.998; SL2=0.995; SL3=0.998), and there was no statistical difference between the measurements of the SL models (p>0.05). PM and SL model measurements were found to be in good agreement, with only 3.57% of the observed differences between the same measurement being located outside 95% limits of agreement according to Bland and Altman (0.43 and -0.40 mm). In the superimpositions of SL-SL and SL-DS models, areas of discrepancy greater than 0.5 mm were observed mainly in interproximal, occlusal, and cervical sites. Conclusion: These results indicate that the home-built SL scanning system did not possess sufficient accuracy and precision for many clinical applications. However, the consistency in preserving the dental proportions suggests that the equipment can be used for planning, storage, and simple clinical purposes.

RESUMO Objetivo: Este estudo avaliou a acurácia e a precisão da aquisição de modelos digitais utilizando um sistema de digitalização caseiro e de baixo custo baseado no método de luz estruturada. Material e Métodos: Para isso, um modelo de gesso (MG) foi digitalizado utilizando o dispositivo experimental (LE) e um scanner dental de mesa (SD). As dimensões dos dentes dos modelos MG e LE foram medidas em triplicata com um paquímetro e digitalmente, respectivamente. A concordância das medidas de cada modelo foi avaliada usando o coeficiente de correlação intraclasse, e a validade entre as diferentes técnicas de medição foi avaliada usando a análise de Bland-Altman. A acurácia e a precisão dos modelos foram investigadas qualitativamente usando a sobreposição de malhas dos modelos LE e SD. Resultados: Um alto coeficiente de correlação intraclasse foi observado em todos os modelos (MG=0,964; LE1=0,998; LE2=0,995; LE3=0,998) e não houve diferença estatística entre as medições dos modelos LE (p>0,05). As medições dos modelos MG e LE mostraram boa concordância, com apenas 3,57% das diferenças observadas entre as mesmas medições localizadas fora dos limites de concordância de 95% de acordo com a análise de Bland-Altman (0,43 e -0,40 mm). Nas sobreposições dos modelos LE-LE e LE-SD, foram observadas áreas de discrepância maiores que 0,5 mm principalmente nos sítios interproximais, oclusais e cervicais. Conclusões: Esses resultados indicam que o sistema de digitalização por luz estruturada caseiro não possui precisão e acurácia suficientes para muitas aplicações clínicas. No entanto, a consistência na preservação das proporções dentárias sugere que o equipamento pode ser usado para planejamento, armazenamento e propósitos clínicos simples.

Evaluation of cardiac contractility of fetuses from pregestational diabetes mellitus pregnancies by three-dimensional ultrasound

SUMMARY OBJECTIVE: This study aimed to evaluate cardiac contractility in fetuses from pregestational diabetes mellitus pregnancies by three-dimensional ultrasound using spatiotemporal image correlation in rendering mode. METHODS: A retrospective cross-sectional study was performed on 40 fetuses from nondiabetic pregnancies and 28 pregestational diabetic pregnancies between 20 and 33 weeks and 6 days. Cardiac contractility was assessed by measuring the ventricular myocardial area in diastole subtracted from the ventricular myocardial area in systole. RESULTS: Pregestational diabetic pregnancies had a lower maternal age than nondiabetic pregnancies (26.7 vs. 39.9 years, p=0.019). Cardiac contractility in fetuses from diabetic and nondiabetic pregnancies was similar (p=0.293). A moderately positive and significant correlation was observed between gestational age and cardiac contractility (r=0.46, p=0.0004). A 1-week increase in gestational age was responsible for a 0.1386 cm2 increase in cardiac contractility. CONCLUSION: Cardiac contractility as evaluated by three-dimensional ultrasound using spatiotemporal image correlation in rendering mode showed no significant differences across fetuses with and without pregestational diabetes.

Protocol for capturing 3D facial meshes for rhinoseptoplasty planning

Abstract Objectives: To present and execute a protocol for the capture of 3D facial images using photogrammetry through the open access software Blender and its add-on OrtogOnBlender (OOB) and to evaluate the compatibility of the 3D meshes generated with Computed tomography (CT) of the sinuses. Methods: Individuals > 18 years old, candidates for Rhinoseptoplasty in a tertiary hospital, were submitted to a photographic session to perform the standardized protocol. In the session, divided into 3 phases, sequential photos were taken for processing the photogrammetry in the OOB and producing 3D meshes of the face. The photogrammetry reconstructions were compared with the reference mesh of the soft tissue surface of the Sinus CT scan to assess compatibility between them. Results: 21 patients were included, 67% female. 3 photogrammetry meshes and 1 CT reference mesh were generated, which demonstrated matching compatibility, as most of the mean distances between cloud points were <1.48mm. Phase 3 of the session with the highest number of photos (54.36 ± 15.05) generated the most satisfactory mesh with the best resolution. Conclusions: The proposed protocol is reproducible and feasible in clinical practice, generated satisfactory 3D meshes of the face, being a potential tool for surgical planning and comparison of results. For the implementation of photogrammetry for use in 3D anthropometry, it is necessary to validate this method. Level of evidence: 3. OCEBM Levels of Evidence Working Group.1 The Oxford 2011 Levels of Evidence. Oxford Centre for Evidence-Based Medicine. http://www.cebm.net/index.aspx?o=5653

Analysis of smile exposure and related factors in young people aged 20 to 30 with convex facial profiles / 口腔疾病防治

Objective @#To study smile exposure in 20- to 30-year-olds with convex facial profiles and to explore the correlation between smile exposure and other aesthetic indicators, as well as psychological factors. @*Methods @# This study obtained ethical approval from the hospital. After they gave informed consent and portrait authorization, 80 young subjects aged 20-30 with convex facial profiles had their dynamic postural smile and spontaneous laughter recorded. The videos were imported into Photoshop CC software, key frames were selected, and the smile exposure was measured. The three-dimensional information of the subject's face in a resting state was obtained, the relevant aesthetic indicators were measured, and the satisfaction degree of their smile and laughter were evaluated. Correlation analysis was conducted for smile exposure and the relevant aesthetic indicators and subjective psychological evaluation.@*Results @# There were statistically significant differences in smile exposure, smile patterns, relevant aesthetic indicators and subjective psychological evaluation between males and females aged 20 to 30 (P<0.05). There was a large gap between males and females in the average opening degree when laughing, males having 5 times that of females, while the average gingival exposure height of the maxillary central incisor in males was approximately 1/2 of that in females. The average nasolabial angle of males (99.80° ± 7.96°) was larger than that of females (96.26° ± 7.31°) (P<0.05), while the average ratio of upper lip length to the length of the lower 1/3 of the face of males (33.73% ± 2.35%) was less than that of females (38.57% ± 2.76%) (P<0.05). The average psychological score of males (57.75±13.46) was higher than that of females (53.69±17.95) (P<0.05). The ratios of maxillary teeth and gingival exposure to oral fissure in the postural smile were positively correlated with the nasolabial angle. The oral fissure width in spontaneous laughter was negatively correlated with psychological score.@*Conclusion @# Convex-faced males and females aged 20 to 30 have different smile exposures and smile patterns. Males tend to smile more openly with a larger opening and less gingival exposure, while females tend to grin with a small opening and more gingival exposure. Smile exposure is positively correlated with nasolabial angle and negatively correlated with smile satisfaction.

Application of three-dimensional image reconstruction technology based on 3D-slicer software in urology / 国际外科学杂志

Objective:To investigate the application value of three-dimensional image reconstruction technology based on 3D-slicer software in urology.Methods:The data of 36 patients with urinary tract diseases admitted to Beijing Friendship Hospital, Capital Medical University from May 2019 to December 2021 were retrospectively analyzed, including 20 males and 16 females; the median age was 53.50(41.75, 66.25) years. There were 10 relative kidney transplant donors, 12 cases with renal tumors, 6 cases with hydronephrosis and 8 patients with urinary calculi. The CT urography data of 36 cases were reconstructed into three-dimensional image models based on 3D-slicer software, and the morphology of the target tissue was measured.Results:In the urinary system model of 10 relative kidney transplant donors constructed in this study, the type of donor renal artery was single artery in 7 cases and accessory renal artery in 3 cases; In the three-dimensional model of 12 tumor kidneys, 4 tumors were located at the upper part of the kidney (2 near ventral and 2 near dorsal), 5 tumors were located at the middle part of the kidney (2 near ventral and 3 near dorsal), and 3 tumors were located at the lower part of the kidney near ventral. The average maximum diameter of the tumors was (27.3 ± 9.63) mm, and the tumor volume was (15.89 ± 5.93) cm 2. The study also successfully constructed a three-dimensional image model of the urinary system in 6 patients with hydronephrosis and 8 patients with urinary calculi (without hydronephrosis). Three-dimensional model image reconstructed by 3D-slicer software clearly showed the spatial structure of renal parenchyma, blood vessels, renal pelvis, calyces and ureter. The diameter, position and direction of ureters and blood vessels can be observed clearly based on the three-dimensional reconstruction model, and clinicians could also evaluate the location, shape, size and adjacent relationship with surrounding tissues of renal cysts, tumors, stones or other masses. Conclusion:3D-slicer software platform can assist clinicians to reconstruct the three-dimensional model of urinary system, which is worthy of further clinical application.

Application of preoperative three-dimensional image reconstruction in the treatment of ureteropelvic junction obstruction / 北京大学学报(医学版)

OBJECTIVE@#To investigate the value of preoperative three-dimensional image reconstruction in the treatment of ureteropelvic junction obstruction (UPJO).@*METHODS@#We reviewed data on 40 patients (22 male cases, and 18 female cases) diagnosed with UPJO in Peking University First Hospital from May 2017 to April 2019. The median age was 26.5 years (IQR 23.25-38.75) years. There were 11 patients complicated with ectopic vessels, 14 patients with kidney stones, 3 patients with horseshoe kidney, and 6 patients with obstruction after pyeloplasty. All the patients underwent preoperative enhanced CT scan, and the CT data were reconstructed into three-dimensional image models. The obstruction position of ureteropelvic junction and the relationship between ureteropelvic junction and blood vessels and organs were observed by three-dimensional models to assist planning surgery. Thirty-seven patients underwent laparoscopic pyeloplasty (including 3 cases combined with pyelolithotomy with flexible cystoscope, 1 case combined with pyelolithotomy by sun-style cystoscope, 1 case with laparoscopic ureter resection and anastomosis, 3 cases of laparoscopic pyeloplasty of horseshoe kidney), 2 patients underwent laparoscopic ventral onlay lingual mucosal graft ureteroplasty, and 1 patient underwent robot-assisted laparoscopic pyeloplasty.@*RESULTS@#Three-dimensional CT image clearly showed the relationship between the obstruction of ureteropelvic junction and blood vessels and organs after three-dimensional reconstruction. The type, diameter, position and direction of the ectopic vessels could be observed clearly before operation according to the three-dimensional reconstruction model, and the number, size, location and shape of renal calculi or other masses, the number of involved renal calyces and the anatomical distribution in the renal pelvis and calyces could be also evaluated preoperatively. After comprehensive analysis of the above information, individualized operation plans were performed on the patients, all the 40 cases were successfully completed with the surgery without any transfer to open surgery. The average operative time was (129.91±37.90) min (range: 75 to 273), the average blood loss was (48.1±78.0) mL (range: 10 to 400), the average hospitality was (5.04±1.99) d (range: 2 to 10), and the average postoperative drainage time was (3.8±1.4) d (range: 2 to 8).@*CONCLUSION@#The preoperative three-dimensional image reconstruction has a high clinical value in the treatment of ureteropelvic junction obstruction, and it is of great help to assist surgery planning and is worthy of further clinical promotion and application.

A precise method of marking pulmonary nodules based on body surface mesh and three-dimensional image reconstruction / 中国胸心血管外科临床杂志

@#Objective    To explore the safety and effectiveness of a precise marking method based on body surface mesh and three-dimensional (3D) image reconstruction. Methods    We retrospectively analyzed the clinical data of 22 patients in our hospital from October 2018 to October 2019. There were 13 males and 9 females aged 58.5 (37-72) years. All patients underwent a precise marking of pulmonary nodules based on body surface mesh and 3D image reconstruction. Then, video-assisted thoracoscopic surgery (VATS) was performed to resect the nodules. The clinical data, including positioning success rate and operation time were analyzed. Results    A total of 22 small pulmonary nodules were removed. The average diameter of small nodules was 12±3 mm, and the average distance from the visceral pleura was 17±6 mm. The localization success rate was 86.4%. The operation time was 110±43 min, and there was no surgery-related complication. Conclusion    The method of marking pulmonary nodules based on body surface mesh and 3D image reconstruction is a safe and reliable technology, which reduces the risk of hemopneumothorax caused by CT-guided lung puncture.

Application of cone beam CT in diagnosis of supernumerary teeth of adolescents / 吉林大学学报(医学版)

Objective: To observe the image and clinical characteristics of the supernumerary teeth of the adolescents, and to elucidate the clinical application value of cone beam CT (CBCT) in the diagnosis of supernumerary teeth. Methods: A total of 146 adolescents with supernumerary teeth scanned by CBCT and comfirmed were selected. The patient's gender, supernumerary teeth localization, number, shape and the root resorption of adjacent teeth were retrospectively analyzed. The changes in the root resorption rates of adjacent teeth induced by different supernumerary teeth shapes were evaluated. Results: The proportion of men to women with supernumerary teeth in 146 patients was 1. 98: 1 (97/49). Among them, 95 (65. 07%) patients were single supernumerary teeth. There were 203 supernumerary teeth in the 146 patients; among them, 132 (65.02%) supernumerary teeth were conical, 112 (55.17%) supernumerary teeth were inverted, and 48 (23.65%) supernumerary teeth were curved root. There was no statistically significant difference between the root resorption rates of adjacent teeth induced by the different shapes of supernumerary teeth (P>0. 05). Conclusion: CBCT can show the localization, the number of supernumerary teeth and other image and clinical charactersistics, which can provide the important evidence for the diagnosis and treatment of supernumerary teeth.

Assessment of Internal Fitness on Resin Crown Fabricated by Digital Light Processing 3D Printer / 치위생과학회지

BACKGROUND: Recently, three-dimensional (3D) printing has been hailed as a disruptive technology in dentistry. Among 3D printers, a digital light processing (DLP) 3D printer has certain advantages, such as high precision and relatively low cost. Therefore, the latest trend in resin crown manufacturing is the use of DLP 3D printers. However, studies on the internal fitness of such resin crowns are insufficient. The recently introduced 3D evaluation method makes it possible to visually evaluate the error of the desired area. The purpose of this study is to evaluate the internal fitness of resin crowns fabricated a by DLP 3D printer using the 3D evaluation method.METHODS: The working model was chosen as the maxillary molar implant model. A total of 20 resin crowns were manufactured by dividing these into two groups. One group was manufactured by subtractive manufacturing system (PMMA), while the other group was manufactured by additive manufacturing system, which uses a DLP 3D printer. Resin crowns data were measured using a 3D evaluation program. Internal fitness was calculated by root mean square (RMS). The RMS was calculated using the Geomagic Verify software, and the mean and standard deviation (SD) were measured. For statistical analysis, IBM SPSS Statistics for Windows ver. 22.0 (IBM Corp., USA) was used. Then, independent t-test was performed between the two groups.RESULTS: The mean±SD of the RMS were 41.51±1.51 and 43.09±2.32 for PMMA and DLP, respectively. There was no statistically significant difference between PMMA and DLP.CONCLUSION: Evaluation of internal fitness of the resin crown made using a DLP 3D printer and subtractive manufacturing system showed no statistically significant differences, and clinically acceptable results were obtained.

Uso da estereofotogrametria para mensuração do volume da anatomia externa da face: revisão sistemática / Use of stereophotogrammetry for measuring the volume of external facial anatomy: a systematic review

Introdução: O registro fotográfico tem sido importante para diversas especialidades médicas como a Cirurgia Plástica. A fotografia em duas dimensões apresenta limitações para capturar profundidade e volume de estruturas outros instrumentos para avaliar essa alteração. Diversas tecnologias foram desenvolvidas para analisar objeto em três dimensões, sendo a estereofotogrametria uma tecnologia que utiliza a análise computadorizada de duas ou mais fotografias simultâneas do objeto para produzir um modelo geométrico em três dimensões. As vantagens da estereofotogrametria incluem menor custo, portabilidade, ausência de radiação e rapidez da captura das imagens. O objetivo deste trabalho foi realizar uma revisão bibliográfica avaliando o uso e a acurácia da estereofotogrametria para mensuração de volume de estruturas na face. Métodos: Foi realizada pesquisa nos bancos de dados Cochrane Library e Medline até maio de 2018 utilizando uma combinação de descritores Mesh e termos livres. Resultados: Foram obtidos inicialmente 2213 estudos observando a estratégia de busca. Seguindo os critérios de elegibilidade, foram selecionados 27 artigos, sendo 21 relatos de casos não randomizados e 6 ensaios clínicos randomizados. A qualidade metodológica dos estudos variou de 50 a 67%, segundo uma pontuação que vai de 0 a 100%. Conclusões: A estereofotogrametria é uma tecnologia promissora e tem sido cada vez mais utilizada para verificar variações de volume na face com alta acurácia e reprodutibilidade. Faltam estudos com melhor qualidade metodológica avaliando a acurácia e o uso da estereofotogrametria na avaliação de volume facial.

Introduction: Photographic documentation is important in several medical specialties, such as plastic surgery. Two-dimensional photography has limitations in capturing structure depth and volume, requiring other instruments to evaluate these changes. Several technologies have been developed for three-dimensional analysis of objects, of which stereophotogrammetry uses computerized analysis of two or more simultaneous photographs of the object to produce a three-dimensional geometric model. The advantages of stereophotogrammetry include lower cost, portability, absence of radiation, and speed of image capture. The aim of the present study was to perform a bibliographic review evaluating the use and accuracy of stereophotogrammetry for measuring the volume of facial structures. Methods: Using a combination of MeSH keywords and free terms, a search was performed in the Cochrane Library and MEDLINE databases. The search included all articles published on or before May 2018. Results: 2,213 studies were initially retrieved using this search strategy. Of these, 27 studies were selected based on the eligibility criteria, of which 21 were non-randomized case studies and 6 were randomized clinical trials. The methodological quality of the studies varied between 50 and 67%, on a grading scale from 0 to 100%. Conclusions: Stereophotogrammetry is a promising technology that is increasingly being used to check for facial volume variations with high accuracy and reproducibility. More studies with higher methodological quality are needed for evaluating the accuracy and use of stereophotogrammetry for facial volume evaluations.

Surgery-first approach with 3D customized passive self-ligating brackets and 3D surgical planning: Case report

ABSTRACT It is possible to unify three-dimensional customized orthodontic techniques and three-dimensional surgical technology. In this case report, it is introduced a treatment scheme consisting of passive self-ligation customized brackets and virtual surgical planning combined with the orthognathic surgery-first approach in a Class III malocclusion patient. Excellent facial and occlusal outcomes were obtained in a reduced treatment time of five months.

RESUMO É possível unificar técnicas ortodônticas personalizadas e tecnologia de planejamento cirúrgico 3D. No presente relato de caso, apresenta-se um plano de tratamento envolvendo o uso de braquetes autoligáveis passivos personalizados e planejamento cirúrgico virtual, combinado com cirurgia ortognática de benefício antecipado, em um paciente com má oclusão de Classe III. Foram obtidos excelentes resultados faciais e oclusais em um tempo reduzido de tratamento, de 5 meses.

Three-dimensional virtual reconstruction as a tool for preoperative planning in the management of complex anorectal fistulas / Reconstrução virtual tridimensional como ferramenta de planejamento pré-operatório de fístulas anais complexas

ABSTRACT The making of three-dimensional virtual models is a promising technology in preoperative planning, but that is not used in the treatment of anorectal fistulas. The objective of this work is to describe the development and initial experience of the construction of a virtual three-dimensional model of the pelvic anatomy of a patient, allowing the exact identification of the relationships between the fistulous tracts of complex anorectal fistulas and the other pelvic structures. An MRI was performed on this patient, and the images were exported to the Vitrea fX Workstation® software. A radiologist did the analysis and segmentation of the images that were then sent to a three-dimensional image processor (Meshlab v. 1.3.3 - ISTI - CNR Research Center, Pisa University, Italy®). The final 3D color image was analyzed by the surgeon and used to guide the catheterization of the fistulous pathways, the internal orifice and to assist in the identification of adjacent structures. The final three-dimensional model presented a high correlation with the intraoperative findings and facilitated the surgical planning.

RESUMO A criação de modelos virtuais tridimensionais é uma tecnologia promissora no planejamento pré-operatorio, entretanto não é utilizada no tratamento de fistulas anais. O objetivo desse trabalho é descrever o desenvolvimento e a experiência inicial da construção de um modelo virtual tridimensional da anatomia pélvica de um paciente, que permite a identificação exata das relações entre os tratos fistulosos de fistulas anais complexas e as demais estruturas pélvicas. O paciente realizou uma ressonância magnética e as imagens foram exportadas para o programa Vitrea fX software Workstation®. Um radiologista realizou a analise e segmentação das imagens que, em seguida, foram enviadas para um processador de imagens tridimensionais (Meshlab v. 1.3.3 - ISTI - CNR research center, Pisa University, Italy®). A imagem 3D colorida final foi analisada pelo cirurgião e utilizada para guiar a cateterização dos trajetos fistulosos e orifício interno e para auxiliar na identificação das estruturas adjacentes. O modelo tridimensional final apresentou alta correlação com os achados intraoperatorios e facilitou o planejamento cirúrgico.

In vivo 3-dimensional Kinematics of Cubitus Valgus after Non-united Lateral Humeral Condyle Fracture

BACKGROUND: Nonunion of lateral humeral condyle fracture causes cubitus valgus deformity. Although corrective osteotomy or osteosynthesis can be considered, there are controversies regarding its treatment. To evaluate elbow joint biomechanics in non-united lateral humeral condyle fractures, we analyzed the motion of elbow joint and pseudo-joint via in vivo three-dimensional (3D) kinematics, using 3D images obtained by computed tomography (CT) scan. METHODS: Eight non-united lateral humeral condyle fractures with cubitus valgus and 8 normal elbows were evaluated in this study. CT scan was performed at 3 different elbow positions (full flexion, 90° flexion and full extension). With bone surface model, 3D elbow motion was reconstructed. We calculated the axis of rotation in both the normal and non-united joints, as well as the rotational movement of the ulno-humeral joint and pseudo-joint of non-united lateral condyle in 3D space from full extension to full flexion. RESULTS: Ulno-humeral joint moved to the varus on the coronal plane during flexion, 25.45° in the non-united cubitus valgus group and −2.03° in normal group, with statistically significant difference. Moreover, it moved to rotate externally on the axial plane −26.75° in the non-united cubitus valgus group and −3.09° in the normal group, with statistical significance. Movement of the pseudo-joint of fragment of lateral condyle showed irregular pattern. CONCLUSIONS: The non-united cubitus valgus group moved to the varus with external rotation during elbow flexion. The pseudo-joint showed a diverse and irregular motion. In vivo 3D motion analysis for the non-united cubitus valgus could be helpful to evaluate its kinematics.

Novel Three-Dimensional Image-Guided Surgery: Application of a Computed Tomography-Based Three-Dimensional Model Using a Tablet Device

OBJECTIVE: A tablet device has several medical applications because it's portability. Most importantly, its powerful graphics and touch-based features have several benefits in the surgical field, especially for generating three-dimensional (3D) images based on patients' computed tomography (CT) scans. METHODS: In this study, 3D objects were manipulated by an operator on an iPad during several laparoscopic surgeries of intra-abdominal organs. Before surgery, 3D structures, such as vessels, soft tissues, and bones, were reconstructed by the surgeon using the patients' CT scans on the patients' bed-side personal computer. RESULTS: In this study, 3D image-guided surgeries were performed using an iPad in five patients. The benefits of this technique were recorded and analyzed in detail by the surgeon. CONCLUSION: Although in a pilot phase with unresolved issues, direct intra-operative handling of a patient-tailored 3D model developed using a tablet device could be useful compared with conventional two-dimensional imaging.

Os modelos ortodônticos digitais são confiáveis? Uma revisão sistemática / Are the digital orthodontics models reliable? A systematic review

Introdução: Os modelos ortodônticos digitais são alternativas ao uso de modelos ortodônticos em gesso. Devido sua importância no diagnóstico, faz-se necessário averiguar a precisão dos softwares de modelos ortodônticos digitais disponíveis no mercado. Objetivo: Evidenciar qual software de modelos ortodônticos digitais possui maior confiabilidade. Material e métodos: Foi realizada busca sistemática nas seguintes bases de dados eletrônicas: Scopus, PubMed, Web of Science, Embase e Cochrane, Grey Literature e Clinical Trials, sem limitações quanto ao ano de publicação ou idioma. Foram incluídos estudos laboratoriais que utilizaram softwares destinados a geração de modelos ortodônticos digitais, comparando-os com modelos ortodônticos em gesso. Após seleção por título e resumo, os artigos potencialmente elegíveis foram lidos na íntegra. A qualidade metodológica e o risco de viés dos artigos incluídos foram avaliados de acordo com as descrições dos modelos, técnicas de medição e análises estatísticas. A qualidade metodológica foi classificada em alta, moderada ou baixa. Resultados: 13.333 artigos foram encontrados nas bases de dados utilizadas. Após a aplicação dos critérios de elegibilidade e remoção de duplicações, restaram apenas 41 artigos. 29 foram considerados de qualidade moderada e 12 de alta qualidade. A classificação quanto à confiabilidade variou de menos confiaveis, equivalentes e a mais confiaveis. Apresentando diferenças estatisticas em suas mensurações (p<0,05); sem significância clínica. Conclusão: os modelos ortodônticos digitais apresentaram mensurações acuradas, reprodutíveis e confiáveis quando comparado ao método convencional utilizando modelos de gesso.

Introduction: Digital models are an alternative for the use of orthodontic models in plaster. Due to its importance in the orthodontic dignified, it is necessary to ascertain the accuracy of the software of digital orthodontic models available in the market. Objective: To show which software of digital orthodontic models has greater reliability. Material and methods: A systematic search was performed in the following electronic databases: Scopus, PubMed, Web of Science, Embase and Cochrane, Gray Literature and Clinical Trials, with no limitations on year of publication or language. We included laboratory studies using digital orthodontic models, comparing them with orthodontic models of plaster through the evaluation of reliability through measurement techniques. After selection by title and abstract, potentially eligible articles have been read in full. The methodological quality and risk of bias of the included articles were evaluated according to the descriptions of the models, measurement techniques and statistical analyzes. The methodological quality was classified as high, moderate or low. Results: 13,333 articles were found in the databases used. After applying the eligibility criteria and removing duplicates, only 41 articles remained. 29 were considered of moderate quality and 12 of high quality. The ranking of digital models for reliability ranged from less reliable, equivalent, and more reliable. Presenting statistical differences in their measurements (p <0.05), without clinical significance. Conclusion: The measurements made in digital models can be as accurate, reproducible and reliable as the conventional method using plaster models.

Acurácia e precisão do método de colagem indireta de bráquetes ortodônticos utilizando tecnologia CAD/CAM / Accuracy and precision of digital indirect bonding method with CAD/CAM technology

A colagem indireta pode ser definida como o posicionamento dos bráquetes ortodônticos em modelos, previamente à colagem clínica. A inclusão dos modelos digitais na ortodontia permite o planejamento virtual das posições dos acessórios ortodônticos. O objetivo deste estudo foi avaliar a acurácia e precisão entre diferentes ortodontistas em relação à colagem indireta com planejamento digital. A amostra foi composta por 33 ortodontistas que realizaram a colagem indireta em 33 modelos prototipados (superior ou inferior) da mesma má oclusão. Cada ortodontista preencheu um questionário com dados como tempo de formação profissional e se possuía experiência clínica com colagem indireta. Foram utilizados 2 tipos de bráquetes diferentes no estudo: MiniSprint® e BioQuick® (Forestadent). O planejamento digital do posicionamento dos bráquetes foi realizado previamente no software OrthoAnalyzer® nos modelos digitais utilizando a sobreposição com a tomografia. Os modelos com os bráquetes em posição foram utilizados para a confecção e impressão das guias. Após realizada a colagem indireta, os 33 modelos foram escaneados com scanner intraoral Trios® para obtenção de modelos digitais que foram superpostos aos modelos do planejamento virtual original. Para análise das diferenças nos posionamentos dos bráquetes foram confeccionados três planos: corte sagital para o plano vertical, corte axial para o plano horizontal e corte coronal para o posicionamento quanto à angulação. Foi verificada a reprodutibilidade intra e interexaminador solicitando-se que 3 ortodontistas repetissem o procedimento de colagem indireta. Para verificação da reprodutibilidade do método de obtenção das medidas, o mesmo operador repetiu o procedimento. Foi aplicada ANOVA de fatores repetidos para verificar as diferenças entre os bráquetes. A ANOVA Multivariada foi aplicada para analisar a influência dos fatores experiência com colagem indireta e formação profissional. O Coeficiente de Correlação Intraclasse (CCI) e os Gráficos Altman Bland foram utilizados para avaliação da reprodutibilidade intraexaminador. O teste de Kaplan-Meier verificou a reprodutibilidade interexaminador. Os resultados mostraram que as diferenças entre os posicionamentos dos bráquetes não foram estatisticamente significantes (p>0,05), com exceção dos bráquetes do grupo BioQuick Inferior quanto ao posicionamento mésiodistal (p=0,016). A análise descritiva das diferenças no posicionamento, mostram que em geral essas foram mínimas sem que houvesse significância clínica (média das diferenças: de 0,08mm a 0,42mm ocluso-gengival, de 0,04mm a 0,13mm mésio-distal e de 0,45º a 2,03º quanto à angulação). Não houve influência significativa (p=0,314 e p=0,158) dos fatores referentes à experiência clínica do ortodontista. A reprodutibilidade entre os ortodontistas foi confirmada e não houve diferença significativa verificada com Kaplan-Meier (p = 0,914). Houve também confirmação da reprodutibilidade do método de medição utilizado. Concluiuse que a técnica de planejamento digital da colagem indireta apresentou acurácia e precisão. Foi confirmada a reprodutibilidade intra e interexaminador da colagem indireta em questão.

The indirect bonding allows the positioning of the brackets on a plaster model before the clinical bonding. The current use of digital models in orthodontics routine made possible to develop virtual setups and positioning brackets with digital indirect bonding. The aim of this study was to evaluate the accuracy and precision of digital indirect bonding, analysing the differences in brackets positions after bonding with the use of a prototyped transfer tray. The sample of the study included 33 orthodontists that made the indirect bonding on 33 prototyped models (upper or lower) of the same malocclusion, using 33 prototyped transfer trays. Each orthodontist previously answered a survey which included their experience with indirect bonding and their professional experience since graduation. Two different sets of brackets were used: MiniSprint® and BioQuick® (Forestadent). The digital indirect bonding was made by positioning the brackets on the digital models (the superimposition with the tomography was also made) with OrthoAnalyzer® (3Shape) software and these images were used to create the digital transfer tray that was sent for 3D printing. After indirect bonding was performed, the prototyped models with the brackets were scanned using an intraoral scanner (Trios®, 3 Shape). Then, superimpositions were made between the digital models obtained after indirect bonding and the digital models from the original setup. To analyze and measure the differences in brackets positions 3 planes were made on each bracket: sagital or vertical plane, axial or horizontal plane and coronal plane to measure angulation. The interexaminer and intraexaminer reproducibility were evaluated by asking to 3 orthodontists to repeat the indirect bonding after 15 days interval. To evaluate the reliability of the method that was used to measure the brackets positions, the same evaluator repeated the measures in 4 different digital models. The repeated factor ANOVA was conducted to analyse the differences between positions of the brackets on the virtual setups and after the indirect bonding. The multivariated ANOVA was applied to verify the influence of the orthodontists' experience on the results. To evaluate the intraexaminer reliability the Intraclass Correlation Coeficiente was applied and for the interexaminer reliability the Kaplan-Meier test was calculated. The results demonstrated that diferences between brackets positions were not statistically significant, except for mesial-distal discrepancies in BioQuick lower models group (p = 0,016). Nevertheless, the descriptive analysis presented that the mean differences were too small to be considered clinically significant (mean differences: from 0,08mm to 0,42mm occlusogingivally, from 0,04mm to 0,13mm mesial-distal and from 0,45º to 2,03º for angulation). There was no significant influence of orthodontists' experience (p=0,314 and p=0,158) on the differences observed. The intraexaminer and interexaminer reproducibility for the orthodontists were confirmed and the differences were not statistically significant for KaplanMeier results (p = 0,914). The intraexaminer reliability for the method of measurements was also confirmed in all 4 models. In conclusion, the digital indirect bonding presented accuracy and precision in bracket positions and reproducibility within orthodontists.

The effect of hard tissue surgical changes on soft tissue displacement: a pilot CBCT study

ABSTRACT Introduction: This pilot study had as main objective to test the reliability of a new method to evaluate orthognathic surgery outcomes and also, to understand the effect of hard tissue changes on soft tissue displacement. Methods: The sample consisted of eight patients that underwent bimaxillary advancement and had CBCT at two time points (before surgery and 6-8 months follow-up). Voxel-based cranial base superimposition was used to register the scans. A different technique of iterative closest point (ICP) was used to measure and correlate the changes. The average displacement of 15 areas (4 hard tissue and 11 soft tissue) were measured twice. Results: ICC was > 0.99 for all areas. Changes in the tip of the nose did not correlate with changes in any maxillary area, whereas soft tissue A point, A point and upper lips had correlation with several areas. The highest correlation for the maxilla was between the upper lip and the left/right supra cheilion (p< 0.001, r= 0.91 and p< 0.001, r= 0.93, respectively). In the mandible, the majority of the correlations involved soft tissue pogonion, pogonion and lower incisors, with the strongest one between pogonion and lower incisors (p< 0.001, r= 0.98). Conclusion: With the proper case selection, ICP is a reliable method that can be used to assess three-dimensional changes.

RESUMO Objetivo: o objetivo deste estudo piloto foi testar a confiabilidade de um novo método para avaliar os resultados da cirurgia ortognática e entender o efeito das alterações dos tecidos duros no deslocamento dos tecidos moles. Métodos: a amostra selecionada consistiu de oito pacientes submetidos a avanço bimaxilar que possuíam TCFC em dois períodos de tempo (antes da cirurgia e de 6 a 8 meses após a cirurgia). A sobreposição da base do crânio pelo método voxel-based foi utilizada para registrar as varreduras, enquanto uma técnica diferente, de ponto iterativo mais próximo (ICP), foi usada para medir e correlacionar as mudanças. O deslocamento médio de 15 áreas (4 em tecidos duros e 11 em tecidos moles) foi mensurado duas vezes. Resultados: o ICC foi > 0,99 para todas as áreas. As alterações da ponta do nariz não se correlacionaram com alterações em qualquer área da maxila, enquanto o ponto A em tecido mole, o ponto A e os lábios superiores apresentaram correlação com várias áreas. A maior correlação para a maxila foi entre o lábio superior e a supracomissura esquerda/direita (p< 0,001, r = 0,91 e p< 0,001, r = 0,93, respectivamente). Na mandíbula, a maioria das correlações envolveu o pogônio em tecido mole, pogônio e incisivos inferiores, sendo a maior entre pogônio e incisivos inferiores (p< 0,001, r= 0,98). Conclusão: com a seleção adequada do caso, o ICP é um método confiável que pode ser utilizado para avaliar mudanças tridimensionais.

COMPARISON BETWEEN RENDERING 3D-CT AND TRANSPARENT 3D-CT IN ACL TUNNEL POSITIONING / COMPARAÇÃO ENTRE 3D-TC POR RENDERIZAÇÃO E 3D-TC POR TRANSPARÊNCIA NO POSICIONAMENTO DE TÚNEIS DO LCA

ABSTRACT Objective: To compare the transparent 3D computed tomography (CT) image protocol against conventional 3D-CT image-rendering protocol to assess femoral tunnel position in anatomic anterior cruciate ligament (ACL) reconstructions . Methods: Eight knee CT scans from cadavers were analyzed by image rendering 3D-CT protocol, using Rhinoceros(r) software. The central point of the ACL tunnel was set using the sagittal plane. Same CT scans were analyzed using transparent 3D-CT measurement protocol with OsiriX(r) software. Central point of the ACL tunnel was set using sagittal, coronal and axial planes. The grid system described by Bernard and Hertel was used to compare tunnel positions between protocols, using height and length parameters . Results: There was a significant difference between measurements using image rendering 3D-CT and transparent 3D-CT protocol for height (23.8 ± 7.9mm and 33.0 ± 5.0mm, respectively; p=0.017) and no differences for length (18.6 ± 4.2mm and 18.3 ± 4.5mm, respectively; p=0.560) . Conclusion: Height in transparent CT protocol was different and length was the same as compared to 3D-CT rendering protocol in Bernard and Hertel method for tunnel measurements. Level of Evidence II, Descriptive Laboratory Study.

RESUMO Objetivo Comparar o protocolo de tomografia computadorizada (TC) 3D por transparência com o protocolo TC-3D por renderização de imagem na avaliação do posicionamento de túneis femorais na reconstrução anatômica do ligamento cruzado anterior (LCA) . Método: Oito TC de joelho de cadáveres foram analisadas pelo protocolo de renderização de imagem 3D-TC utilizando o software Rhinoceros(r). O ponto central do túnel do LCA foi definido pelo plano sagital. As mesmas tomografias foram analisadas pelo protocolo 3D-TC por transparência, com o software OsiriX(r). O ponto central do túnel do LCA foi definido pelos planos sagital, coronal e axial. O sistema de grade de Bernard e Hertel foi utilizado para comparar a posição dos túneis entre os protocolos, utilizando parâmetros para comprimento e altura. Resultados: Houve diferença significativa entre as medidas dos protocolos de renderização de imagem 3D-TC e 3D-TC por transparência para altura (23,8 ± 7,9mm e 33,0 ± 5,0mm, respectivamente; p=0,017), sem diferenças para comprimento (18,6 ± 4,2mm e 18,3 ± 4,5mm, respectivamente; p=0,560) . Conclusão: A altura no protocolo de TC por transparência foi diferente e o comprimento foi igual quando comparados com o protocolo 3D-TC por renderização de imagem no método de Bernard e Hertel para mensuração dos túneis. Nível de Evidência II, Estudo Laboratorial Descritivo.

Three-dimensional data fusion method for tooth crown and root based on curvature continuity algorithm / 北京大学学报(医学版)

Objective:To explore a three-dimensional (3D) data fusion and integration method of optical scanning tooth crowns and cone beam CT (CBCT) reconstructing tooth roots for their natural transition in the 3D profile.Methods: One mild dental crowding case was chosen from orthodontics clinics with full denture.The CBCT data were acquired to reconstruct the dental model with tooth roots by Mimics 17.0 medical imaging software, and the optical impression was taken to obtain the dentition mo-del with high precision physiological contour of crowns by Smart Optics dental scanner.The two models were doing 3D registration based on their common part of the crowns'' shape in Geomagic Studio 2012 reverse engineering software.The model coordinate system was established by defining the occlusal plane.crown-gingiva boundary was extracted from optical scanning model manually, then crown-root boundary was generated by offsetting and projecting crown-gingiva boundary to the root model.After trimming the crown and root models, the 3D fusion model with physiological contour crown and nature root was formed by curvature continuity filling algorithm finally.In the study, 10 patients with dentition mild crowded from the oral clinics were followed up with this method to obtain 3D crown and root fusion models, and 10 high qualification doctors were invited to do subjective evaluation of these fusion models.Results: This study based on commercial software platform, preliminarily realized the 3D data fusion and integration method of optical scanning tooth crowns and CBCT tooth roots with a curvature continuous shape transition.The 10 patients'' 3D crown and root fusion models were constructed successfully by the method, and the average score of the doctors'' subjective evaluation for these 10 models was 8.6 points (0-10 points).which meant that all the fusion models could basically meet the need of the oral clinics, and also showed the method in our study was feasible and efficient in orthodontics study and clinics.Conclusion: The method of this study for 3D crown and root data fusion could obtain an integrate tooth or dental model more close to the nature shape.CBCT model calibration may probably improve the precision of the fusion model.The adaptation of this method for severe dentition crowding and micromaxillary deformity needs further research.

Three-Dimensional Fast Spin-Echo Imaging without Fat Suppression of the Knee: Diagnostic Accuracy Comparison to Fat-Suppressed Imaging on 1.5T MRI

PURPOSE: To evaluate the diagnostic performance of three-dimensional fast spin-echo (3D FSE-Cube) without fat suppression (NFS) for detecting knee lesions, using comparison to 3D FSE-Cube with fat suppression (FS). MATERIALS AND METHODS: One hundred twenty-four patients who underwent 1.5T knee magnetic resonance imaging (MRI) scans and 25 subsequent arthroscopic surgeries were retrospectively reviewed. Using arthroscopic results and two-dimensional images as reference standards, diagnostic performances of 3D FSE-Cube-NFS and FS imaging about lesions of ligament, meniscus, subchondral bone marrow edema (BME), and cartilage were compared. Scan parameters of 3D FSE-Cube imaging were previously optimized by a porcine knee phantom. RESULTS: No significant differences were observed between detection rates of NFS and FS imaging for detecting lesions of meniscus and cartilage (p>0.05). However, NFS imaging had lower sensitivity for detection of medial collateral ligament (MCL) tears, and lower sensitivity and specificity for detection of BME lesions, compared to FS imaging (p<0.05). CONCLUSION: 3D FSE-Cube-NFS imaging showed similar diagnostic performance for detecting lesions of meniscus or cartilage compared to FS imaging, unlike MCL or BME lesions.