Evaluation of angles of the tracheobronchial tree with the 3-dimensional reconstruction method: a morphometric and radiologic study / Evaluación de los ángulos del árbol traqueobronquial con el método de reconstrucción tridimensional: un estudio morfométrico y radiológico

SUMMARY: The objective of the current research is to assess the branching angles of the tracheobronchial tree and the correlation between these angles and the lung volume using the 3-dimensional reconstruction method. Thorax CT (computed tomography) images of 150 individuals, who were over 18 years of age and did not have any pathology on CT, were obtained retrospectively. A 3-dimensional reconstruction of the trachea, bronchi, and lungs was carried out. External and internal angles between the trachea and main bronchi, between the main bronchi and lobar bronchi, and between the lobar bronchi were measured. The volume measurement of the right and left lungs was performed. The individuals included in the study were grouped by sex and age (20-40 years, 41-61 years, and 62-87 years). The left subcarinal angle (LSA), total subcarinal angle (TSA), and left interbronchial angle (LIA) were found to be greater in the 62-87 age group. Both the external angle (LULB-LMBE) and the internal angle (LULB- LMBI) between the left upper lobar bronchus and the left main bronchus were observed to be greater in males. In males, a statistically significant negative moderate correlation was identified between the right lung volume and the right subcarinal angle (RSA). In females, a statistically significant positive moderate correlation was revealed between the external (RULB-IBE) and internal angles (RULB-IBI) between the right upper lobar bronchus and the intermediate bronchus, and the right lung volume. In the literature review we performed, we did not find any studies investigating the correlation between the branching angles of the tracheobronchial tree and the lung volume using the 3-dimensional reconstruction method. Therefore, we are of the opinion that our study will contribute to the literature.

El objetivo de la investigación fue evaluar los ángulos de ramificación del árbol traqueobronquial y la correlación entre estos ángulos y el volumen pulmonar utilizando el método de reconstrucción tridimensional. Se obtuvieron retrospectivamente imágenes de tomografía computarizada de tórax de 150 individuos mayores de 18 años sin patología. Se realizó una reconstrucción tridimensional de la tráquea, los bronquios y los pulmones. Se midieron los ángulos externo e interno entre la tráquea y los bronquios principales, entre los bronquios principales y los bronquios lobares, y entre los bronquios lobares. Se realizó la medición del volumen de los pulmones derecho e izquierdo. Los individuos incluidos en el estudio fueron agrupados por sexo y edad (20-40 años, 41-61 años y 62-87 años). Se encontró que el ángulo subcarinal izquierdo, el ángulo subcarinal total y el ángulo interbronquial izquierdo eran mayores en el grupo de edad de 62 a 87 años. Tanto el ángulo externo (LULB-LMBE) como el ángulo interno (LULB-LMBI) entre el bronquio lobular superior izquierdo y el bronquio principal izquierdo era mayor en los hombres. En los hombres, se identificó una correlación moderada negativa estadísticamente significativa entre el volumen pulmonar derecho y el ángulo subcarinal derecho. En mujeres, se reveló una correlación positiva moderada estadísticamente significativa entre los ángulos externos (RULB-IBE) e internos (RULB-IBI) entre el bronquio lobar superior derecho y el bronquio intermedio, y el volumen pulmonar derecho. En la revisión bibliográfica que realizamos, no encontramos ningún estudio que analizara la correlación entre los ángulos de ramificación del árbol traqueobronquial y el volumen pulmonar utilizando el método de reconstrucción tridimensional. Por lo tanto, consideramos que nuestro estudio contribuirá a la literatura especializada del tema.

Morphometric examination of the trachea and bronchi in follow-up computed tomography scans of COVID-19 patients / Examen morfométrico de la tráquea y los bronquios en tomografías computarizadas de seguimiento de pacientes con COVID-19

SUMMARY: The purpose of this study is to evaluate changes in the trachea and bronchi using 3-dimensional reconstruction images obtained from the initial and follow-up computed tomography (CT) scans of COVID-19 patients. A hundred COVID-19 patients over the age of 18 were included in our study. CT images were transferred to Mimics software, and a 3-dimensional reconstruction of the trachea and bronchi was performed. The initial and follow-up CT images of COVID-19 patients were graded as none (grade 0), mild (grade 1), moderate (grade 2), and severe (grade 3) according to the total lung severity score. The patients were divided into progression and regression groups according to the grade increase/decrease between the initial and follow-up CTs. Moreover, the patients were divided into groups as 0-2 weeks, 2-4 weeks, 4-12 weeks, and over 12 weeks according to the duration between the initial and follow-up CTs. The mean cross-sectional area, circumference, and diameter measurements of the right upper lobar bronchus, intermediate bronchus, middle lobar bronchus, and left lower lobar bronchus decreased in the follow-up CTs of the progression group. This decrease was not found to be statistically significant. In the follow-up CTs of the regression group, the left upper lobar bronchus and left lower lobar bronchus measurements increased but not statistically significant. Upon comparing the onset of the disease and the follow-up period, statistically significant changes did not occur in the trachea, main bronchus, and lobar bronchus of COVID-19 patients.

El propósito de este estudio fue evaluar los cambios en la tráquea y los bronquios utilizando imágenes de reconstrucción tridimensionales obtenidas de las tomografías computarizadas (TC) iniciales y de seguimiento de pacientes con COVID-19. En nuestro estudio se incluyeron 100 pacientes con COVID-19 mayores de 18 años. Las imágenes de TC se transfirieron al software Mimics y se realizó una reconstrucción tridimensional de la tráquea y los bronquios. Las imágenes de TC iniciales y de seguimiento de los pacientes con COVID-19 se calificaron como ninguna (grado 0), leve (grado 1), moderada (grado 2) y grave (grado 3) según la puntuación total de gravedad pulmonar. Los pacientes se dividieron en grupos de progresión y regresión según el aumento/disminución del grado entre las TC iniciales y de seguimiento. Además, los pacientes se dividieron en grupos de 0 a 2 semanas, de 2 a 4 semanas, de 4 a 12 semanas y de más de 12 semanas según la duración entre la TC inicial y la de seguimiento. Las mediciones medias del área transversal, la circunferencia y el diámetro del bronquio lobar superior derecho, el bronquio intermedio, el bronquio lobar medio y el bronquio lobar inferior izquierdo disminuyeron en las TC de seguimiento del grupo de progresión. No se encontró que esta disminución fuera estadísticamente significativa. En las TC de seguimiento del grupo de regresión, las mediciones del bronquio lobar superior izquierdo y del bronquio lobar inferior izquierdo aumentaron pero no fueron estadísticamente significativas. Al comparar el inicio de la enfermedad y el período de seguimiento, no ocurrieron cambios estadísticamente significativos en la tráquea, el bronquio principal y el bronquio lobar de los pacientes con COVID-19.

A new way of analyzing tooth movement using universal coordinate system geometry single point superposition in a 3D model

ABSTRACT Introduction: Superposing 3D models is an imminent need. However, current methods rely on marking multiple points on the maxilla and mandible, which could increase point marking and overlapping errors. Objective: This study aimed at developing a method for superimposing 3D models of the maxillary and mandibular arches with Autodesk Inventor® engineering software, using a single universal coordinate system (UCS) point superposition. Methods: A total of 104 STL (stereolithography) models of the maxillary and mandibular arches exported from My iTero® platform were retrospectively selected, in which T0 and T1 were the initial and refinement periods, respectively (n=26 per group). The X, Y, and Z coordinates associated with a single point in each arch were inserted into the models with SlicerCMF® software for model orientation. The arch models with UCS registration were transferred to Autodesk Inventor® for superimposition and to measure tooth movements performed during Invisalign® treatment. Arch expansion, intrusion and rotation were analyzed by two examiners. The statistics were performed using intraclass correlation coefficients (ICC), Dahlberg's formula, and t-test (p<0.05). Results: A reliable method of superimposing 3D digital models using a single UCS point in the maxilla and mandible was developed. ICC showed excellent intra- and inter-examiner correlation (ICC>0.90). A systematic error was not found concerning linear and angular measurements (<1mm and <1.5°, respectively). Digital dental movements could be analyzed, including arch expansion, dental intrusion, and tooth rotation. Conclusions: The developed method was proven reliable and reproducible for superimposing 3D models of the maxillary and mandibular arches by using UCS system.

RESUMO Introdução: A sobreposição de modelos 3D é uma necessidade iminente. No entanto, os métodos atuais dependem da marcação de múltiplos pontos na maxila e na mandíbula, o que pode aumentar a incorporação de erros no processo de sobreposição. Objetivo: O objetivo desse estudo foi desenvolver um método para sobrepor modelos 3D das arcadas superior e inferior utilizando o software de engenharia Autodesk Inventor®, por meio da marcação de um único ponto em cada arcada, usando o sistema de coordenadas universal (UCS). Métodos: No total, 104 modelos STL das arcadas superior e inferior exportados da plataforma My iTero® foram selecionados retrospectivamente, onde T0 foi o período inicial e T1, o de refinamento (n=26 por grupo). As coordenadas X, Y e Z associadas a um único ponto em cada arcada foram inseridas nos modelos usando o software SlicerCMF®. Os modelos com os pontos UCS demarcados foram transferidos para o software Autodesk Inventor® para realizar a sobreposição e medir os movimentos dentários realizados durante o tratamento com Invisalign®. Os movimentos de expansão, intrusão e rotação foram analisados por dois examinadores. A análise estatística foi realizada usando os coeficientes de correlação intra-classe (ICC), fórmula de Dahlberg e teste t (p<0,05). Resultados: Foi desenvolvido um método confiável de sobreposição de modelos digitais 3D usando um único ponto UCS na maxila e mandíbula. O ICC apresentou excelente correlação intra e inter-avaliadores (ICC>0,90). Não foi encontrado erro sistemático nas medidas lineares e angulares (<1mm e <1,5°, respectivamente). Os movimentos dentários puderam ser analisados por meio do método proposto, incluindo expansão da arcada, intrusão e rotação dentária. Conclusão: O método desenvolvido provou ser confiável e reprodutível para sobreposição de modelos 3D das arcadas superior e inferior usando o sistema UCS com marcação de ponto único.

Efficacy and safety of 3-dimensional laparoscopic pyeloplasty and ultrasound-guided flexible ureteroscopy lithotripsy in the treatment of ureteropelvic junction obstruction and renal calculi / 现代泌尿外科杂志

【Objective】 To evaluate the efficacy and safety of 3-dimensional laparoscopic pyeloplasty and ultrasound-guided flexible ureteroscopy lithotripsy (3DLP-UGFURL) in the treatment of ureteropelvic junction obstruction (UPJO) and renal calculi. 【Methods】 The clinical data of 29 patients of UPJO complicated with renal calculi treated with 3DLP-UGFURL during Dec.2017 and Jul.2022 were retrospectively analyzed. There were 23 males and 6 females with average age of (35.3±13.6) years. The lesions were on the left side in 20 cases, on the right side in 9 cases, and all were unilateral. One case was complicated with horseshoe kidney. The body mass index (BMI) was 23.6±3.9. Multiple calculi of renal pelvis or calyces occurred in 16 cases, and the rest were single calculi. The maximum diameter of calculi was (1.2±0.6)cm. There were 2 cases of mild hydronephrosis, 19 cases of moderate hydronephrosis and 8 cases of severe hydronephrosis. 【Results】 All operations were successful. The operation time of 3DLP was (84.2±15.4)min. Operation time of UGFURL was (42.8±15.7)min. Estimated blood loss was (36.9±13.6)mL. Indwelling time of drainage tube was (3.6±1.6)d. Indwelling time of urinary catheter and postoperative hospital stay was (6.8±1.2)d. One month after operation, the stone removal rate was 97.4%. The retention time of ureteral stent was 2.7 months. During the follow-up of (24.5±10.0)months, there were 45 Clavien Dindo grade 1 complications. 【Conclusion】 3DLP-UGFURL is safe and effective in the treatment of UPJO complicated with renal calculi, but it still needs long-term follow-up data.

Dynamic evaluation of left ventricular systolic function in patients with pregnancy-induced hypertension by three-dimensional speckle tracking imaging / 中国基层医药

Objective:To investigate the clinical efficacy of three-dimensional speckle tracking imaging in the dynamic evaluation of left ventricular systolic function in patients with pregnancy-induced hypertension.Methods:50 patients with pregnancy-induced hypertension, who received prenatal examination in Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine from July 2019 to June 2020 and finally gave birth, were included in the observation group. An additional 50 healthy pregnant women who concurrently received prenatal examination were included as controls. All participants underwent routine echocardiography and three-dimensional speckle tracking imaging examinations. Parameters related to left ventricular systolic function were recorded. Routine echocardiography parameters and three-dimensional speckle tracking imaging parameters were compared between the observation and control groups.Results:There were no significant differences in routine echocardiography parameters (including heart rate, left ventricular end-diastolic diameter, interventricular septum thickness in end-diastole, left ventricular posterior wall thickness in diastole, and left ventricular ejection fraction) between before treatment, after treatment, and 3 months after delivery in the observation group, and between observation and control groups before treatment (all P > 0.05). The absolute values of left ventricular global longitudinal strain (LVGLS) [(-18.41 ± 2.23)% vs. (-26.03 ± 2.79)%], left ventricular global circumferential strain (LVGCS) [(31.29 ± 3.09)% vs. (37.45 ± 3.68)%], left ventricular global radial strain (LVGRS) [(-19.37 ± 2.19)% vs. (-24.59 ± 2.74)%], and left ventricular global area peak systolic strain (LVGAS) [(-26.61 ± 3.18)% vs. (-39.23 ± 3.96)%] measured before treatment were significantly lower in the observation group than in the control group ( t = 6.31 -14.87, all P < 0.05). The absolute values of LVGLS, LVGCS, LVGRS, and LVGAS in the observation group were significantly higher after treatment [(-24.79 ± 2.68)%, (35.94 ± 3.25)%, (-22.48 ± 2.41)%, (-37.54 ± 3.38)%] and 3 months after delivery [(-25.64 ± 2.72)%, (36.63 ± 3.47)%, (-23.91 ± 2.69)%, (-38.49 ± 3.64)%] than before treatment ( t = 4.08 - 10.59, P < 0.05). There were no significant differences in LVGLS, LVGCS, LVGRS, and LVGAS between observation group and control groups at each time point studied ( t = 0.47 - 1.19, P = 0.182 - 0.652 > 0.05). The absolute svalues of LVGLS, LVGCS, LVGRS and LVGAS in patients with pregnancy-induced hypertension were positively correlated with left ventricular ejection fraction values ( r = 0.638 - 0.775, P = 0.009 - 0.041 < 0.05). Conclusion:Three-dimensional speckle tracking imaging can be used to dynamically evaluate the impairment of left ventricular systolic function in patients with pregnancy-induced hypertension. This technique helps guide early intervention and prognosis evaluation and has a high clinical application value.

Additive Manufacturing: A 3-Dimensional Approach in Periodontics

Additive manufacturing technology or 3-dimensional printing has been used since ages in various fields including medical. Their addition to dentistry is recent and has tried to revolutionize the field. It is being used in various fields of dentistry like endodontics, prosthodontics, orthodontics, oral and maxillofacial surgery and recently in periodontics and Implantology. With introduction of recent “layer-by-layer” additive technology, their use in periodontal field has changed its treatment planning. It is use in preparation of customized scaffold with or without stem cell therapy, ridge augmentation, sinus lift and guided implant surgery, implant fixtures, education models,drug technology and many more. This review has tried to explain the various applications of the additive manufacturing in the field of periodontics with recent evidences. This paper highlights the role of 3-dimensional printing which can change the future of periodontal management.

Double outlet of right ventricle: imaging spectrum on multi-slice computed tomography

Background: Multi-slice computed tomography (MSCT) is the main stay of pre-operative assessment of many complex congenital heart diseases (CHD) in current clinical practice, one of them is double outlet of right ventricle (DORV). DORV is one of the conotruncal anomalies that encompasses a wide spectrum of anatomic malformations in which both the aorta and pulmonary arterial trunk arise entirely or predominantly from the morphologically right ventricle (RV). Purpose of this article is to understand spectrum of DORV and associated types of ventricular septal defect (VSD) on MSCT imaging with special emphasis of usefulness of 3-D volume rendered (VR) images in pre surgical evaluation.Methods: A total of 500 paediatric patients (<18 years old), who had undergone MSCT were studied during the period 2014 to 2019 at the tertiary cardiac care centre.Results: 500 patients having primary/suspicious diagnosis of DORV on echocardiography during the said period were enrolled in the study. All the patients who underwent MSCT scan, were studied in detail for: DORV spectrum, associated types of VSD and its relationship to the semilunar valves. Out of 500 total subjects, subaortic VSD was the most common type of VSD observed (53%), followed by subpulmonic VSD (22%), non-committed VSD (18%) and doubly committed VSD (7%). Associations of pulmonary stenosis, subaortic stenosis and aortic co-arctation with various types of VSDs were addressed. Associated other anomalies were also analysed.Conclusions: Advances in MSCT technology has revolutionized pre-surgical diagnosis, management approach and post-operative follow-up of DORV patients. Excellent image qualities along with 3D volume rendered images help surgeon understand complex morphology of DORV variants and associated types of VSD. Significant reduction in intra and post-operative mortality in DORV patients in current era is result of MSCT technology.

A Novel Method for Hyperacuity Measurement

PURPOSE: We developed a novel method for measurement of hyperacuity and verified the utility thereof.METHODS: We developed a three-dimensional (3D) hyperacuity test using a 3D liquid crystal flat screen, a left- and right-image polarized display, and liquid crystal shutter glasses. We tested the technique in three groups: normal (n = 48), with cataracts (n = 14), and with macular disease (n = 35). We used a chart consisting of five dots and a reference line. Of the five dots, one was variably shifted from the other dots. A chart was presented to one eye and the reference line or blank image to the other eye; a subject scored positive when the dot in the unusual position was recognized.RESULTS: Hyperacuity was measured in terms of the reference line seen by the reference eye (RR), a blank image seen by the reference eye (RB), the reference line seen by the contralateral eye (CR), and a blank image seen by the contralateral eye (CB). All test scores were significantly lower when the reference line was seen than not (RR vs. RB and CR vs. CB; p < 0.01, respectively). For the RR and CR tests, no significant difference was apparent between the normal and cataracts group (p = 0.553, p = 0.494) but such differences were evident between the normal and macular disease groups (p = 0.028, p = 0.002). Also, visualization of the reference line by the reference and contralateral eyes did not differ (p > 0.05).CONCLUSIONS: Measurement of hyperacuity using our new method was not affected by media opacity but was significantly affected by macular disease. Presentation of a reference line facilitated hyperacuity assessment.

Dosimetric parameters of heart and left ventricle – comparison of 3D CRT and IMRT in left cancer breast

Background: Conformal Radiotherapy techniques adapting to the ballistics of delineated volumes allowed significant reduction in excess radiation induced mortality however the increasing number of long-term survivors and expanding use of cardiotoxic drug highlight the persistent need for maximal cardiac possible sparing. The low dose volume of left ventricle are better predictor of acute coronary events than mean heart dose. Materials and Methods: 38 post-MRM patients were randomized to treatment by 3Dimensional Conformal Radiotherapy (3D CRT) and Intensity Modulated Radiotherapy (IMRT) technique. Two tangential beams were used in 3D CRT technique while five to seven (mostly tangential beams) were used in inversely planned IMRT technique. The dose volume parameters of planning target volume, heart and left ventricle were compared. Results: The dosimetry of Planning target volume showed significantly better coverage in IMRT technique (D90, D95) however the D50 was comparable in both the techniques. In dosimetry of heart, the high dose volumes (V30, V40) were nearly comparable in both the techniques. The other dose volume parameters (V5, V10, V20, V25, D33, D67, D100) and the mean dose were significantly lesser in 3D CRT technique along with significantly better sparing of left ventricle (Dmean and V5). Conclusion: The dosimetry of target volume was better with IMRT technique, but this was accompanied by a huge increase in dose to whole heart and specifically the left ventricle which has strong potential to translate into an increased cardiotoxicity. A better distribution of the target region may be obtained by multiple segmentation of the two tangential fields in 3D CRT plans with further reduction in dose to heart and left ventricle.

Evaluation of 3-Dimensional Titanium Miniplates in Mandibular Fractures

Introduction: Mandibular fractures are one of the mostcommon fractures of facial skeleton because of its prominentposition in maxillofacial region. Traditionally, surgeons haveattempted to achieve: anatomic reduction, immobilization andfixation, prevention of infection and rehabilitation of function.The aim of our study was to evaluate the following parameterslike surgical procedures, infection, hardware failure, wounddehiscence, neurosensoery deficit, and fate of implant.Material and methods: The present study was conducted inthe Department of Oral and Maxillofacial Unit, after obtainingethical clearance. A total of 20 patients were selected toevaluate the usefulness of 3-Dimensional titanium miniplatesin fixation of mandibular fractures. After surgical exposure,either straight 6 holed or 8 holed or curved 8 holed 3-Dtitanium miniplates are placed. The patients were in the agegroup of 21-40 years. Etiology of trauma in most of the patientwas Road traffic accident (70%).Result: The frequency of fracture site being mainlyparasymphysis fracture (50%). Two patients had infection(10%). None of the patients had malunion or nonunion. The3-Dimensional titanium miniplates are suitable for fixation ofsimple mandibular fractures and an easy to use alternative toconventional miniplates.Conclusion: This plate is associated with good stability offracture segments and low infection rate

Precision repairing of compound tissue defect at limbs by 3-Dimentional contrast printing and fibular head compound tissue flap transplantation / 中华显微外科杂志

Objective To explore the clinical application and effect of fibular head compound soft tissue flap transplantation on precision repairing of compound tissue defect at limb joints assisted by 3-Dimensional contrast printing technology.Methods From March,2014 to September,2017,9 patients with bone and soft tissue defect at limb joints were selected.In which,2 were distal radius bone defect with joint capsule and ligament defect,2 were lower segment tibia bone and soft tissue defect,2 were femur under section of the bone and soft tissue defect,2 were medial malleolus bone and ligament defect,and 1 was external ankle ligament and bone defect.Using 3-Dimensional printing to conduct bilateral mirror-image contrast prior to the operation,morphology of bone defect at limb joints was acquired.Based on the texture printed out,corresponding fibular head compound blocks with blood vessels were removed from the donor site and transplanted to the recipient site before anastomosing the blood vessels and restoring the blood flow.The regular post-operative followed-up was performed.Results The 9 transplanted tissue blocks survived.The donor sites and the recipient sites were healed.The followed-up for restoration of limb function was from 9 to 35 (average,17.5) months.The ankle function was assessed according Kofoed scale,resulted in 2 excellent and 1 good;The wrist function was assessed according Mayo scale,resulted in 1 excellent and 1 good.The medial malleolus bone defect and criteria bone defect were healed at 6 months.The patients were satisfied with the efficacy.Conclusion The application of 3-Dimensional contrast printing of fibular head compound tissue flap transplantation in repairing compound tissue defects at limb joints can reduce damage to the donor site,realizing precise repairing on limb tissue defect,and make good function restoration.

MDCT with three-dimensional fusion images in the preoperative evaluation of pancreaticoduodenectomy / 中华肝胆外科杂志

Objective To study the role of MDCT with 3D fusion images in the preoperative evaluation of pancreaticoduodenectomy.Methods 37 patients who underwent pancreaticoduodenectomy from March 2016 to May 2018 in the Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University were included in this retrospective study.All patients underwent a dual-phase enhanced MDCT before operation.The volume data of enhanced MDCT were transmitted to a dedicated CT post-processing workstation.The 3D images,including the tumor,pancreas,portal vein system,arterial system,pancreatic and biliary tract,were reformatted respectively before the fusion imaging.Two reviewers analyzed the tumor location and its spatial relations with the pancreaticobiliary system,peripancreatic vessels and vascular variations by means of zooming,rotating,splitting and transparent displaying on fusion images.Then,the assessed items were compared to the surgical and pathological findings.Results The 3D fusion images of 37 patients in this study depicted the tumor,pancreas,peripancreatic vessels and pancreatic and biliary tract clearly.Compared with the intraoperative and pathological findings,the accuracy of both tumor detection and localization with the 3D fusion images was 100％.To compare the intraoperative findings,visualization and variation detection of the celiac,splenic,common hepatic,gastroduodenal,hepatic,and superior mesenteric arteries,and the superior mesenteric and portal veins were all 100％.Visualizations of the anterior superior pancreaticoduodenal artery (ASPDA),posterior superior pancreaticoduodenal artery (PSPDA),inferior pancreaticoduodenal artery (IPA) and dorsal pancreatic artery (DPA) were 85.7％,82.8％,72.2％ and 75.8％,respectively.Conclusion The MDCT 3D fusion imaging technology allowed one stop preoperative assessment of pancreaticoduodenectomy,especially in clearly outlining the tumor location and its spatial relations with the surrounding surgical anatomies before surgery.

Three-dimensional evaluation of the machinability of monolithic CAD/CAM-generated posterior crowns by nano-hybrid ceramic / 대한치과재료학회지

The purpose of this study comparatively analyzed the machinability of various dental hybrid blocks manufactured by using the CAD/CAM system. Three hybrid composite blocks (Vita enamic, Lava Ultimate, GC Cerasmart) were used for experimental groups and one conventional ceramic block (Vita Mark II) was used for control. The digital impression of the master model and abutment was taken by using a scanner, and then the CAD software program was used to design restorations. The four-axis milling machine (inLab MCXL; Sirona Dental Systems GmbH, Bensheim, Germany) was used four materials. The digitized data was superimposed with 3D inspection software to quantitatively obtain the machinability of a ceramic crown, and visual differences were confirmed with a color map. The root mean square (RMS) values of ceramic crown group were statistically analyzed with one-way ANOVA (α=0.05). While there was a significant difference in the machinability of the internal surface, among four groups, there was statistically significant difference between conventional (VM group) and hybrid ceramic (VE, LU, GC groups) (p<0.05). Consequently, the machinability of VM is lower than that of other hybrid ceramics, and the machinability of VE is better than that of LU and GC. For ceramics as final restorations, manufacturing of dental restorations using hybrid composite ceramic is recommended.

Variations in shoulder loading due to differences in the site of stepping foot contact during baseball pitching - Comparison between flat ground and mound conditions - / 体力科学

This study examined variations in shoulder loading due to differences in the site of stepping foot contact during baseball pitching, while comparing flat ground and mound conditions. Measurement was performed, involving 10 right-handed pitchers who belonged to university baseball clubs, under original flat ground and mound conditions. Pitching movements were classified into 3 categories: [normal], [narrow], and [outside]. Through 3-dimensional motion analysis using a motion capture system, the following results were obtained: 1. The pitching velocity was significantly higher in the [normal] compared with [narrow] and [outside] conditions and under the mound compared with flat ground condition. 2. The peak torque of the shoulder internal rotation was markedly lower in the [narrow] compared with [normal] condition. There were no significant differences between the [normal] and [outside] conditions or between the flat ground and mound conditions. 3. The posterior, superior, and inferior shearing forces, as well as the proximal traction force, which influence the humeral head of the shoulder, were markedly greater in the [normal] compared with [narrow] and [outside] conditions. The anterior and posterior shearing forces and proximal traction force were significantly greater under the mound compared with flat ground conditions. Based on the results, the internal rotation torque of the shoulder, as well as the shearing and traction forces influencing the humeral head of the shoulder, may vary due to differences in the site of stepping foot contact during baseball pitching and between flat ground and mound conditions. The former may also be useful to prevent pitching-related shoulder injuries.

Three-Dimensional Analysis of Mouse Habenula Subnuclei Reveals Reduced Volume and Gene Expression in the Lipopolysaccharide-mediated Depression Model

The habenula (Hb) is small but important brain structure, anatomically and functionally links the forebrain with the midbrain to modulate various neuropsychiatric functions associated with drug addiction and emotion-associated dysfunctions. Several reports suggested that the dysfunction of Hb-related functions affected the Hb structurally and functionally. However, the technical limitation has awaited the solid conclusion of whether Hb change due to depression is likely to occur in certain subnuclei of the Hb. To probe this possibility, we developed 3-dimensional reconstruction methods for the high-resolution volumetric analysis of Hb and the mRNA levels at the given volume in normal or lipopolysaccharide (LPS)-mediated mouse model of depression. Notably, we discovered that the volume reduction was prominent in medial Hb but not in lateral Hb after LPS treatments. On the other hand, the RNA expression levels of known Hb regional markers such as Tac1 (dorsal part of medial Hb), ChAT (ventral part of medial Hb), and Tacr1 (medial and lateral Hb) were all decreased in all Hb subnuclei in LPS-injected mice. Accordingly, accurate volumetry with marker labeling was not feasible. Collectively, these established 3D analyses of mouse Hb successfully and precisely determine the volume-based changes of small brain structure, which should be applicable in a wider range of mouse models or pathological specimens.

Fabrication of additive manufacturing interim denture and comparison with conventional interim denture: A case report / 대한치과보철학회지

With development of digital dentistry, the 3-dimensional (3D) manufacturing industry using computer-aided design and computer-aided manufacturing (CAD/CAM) has grown dramatically in recent years. Denture fabrication using digital method is also increasing due to the recent development of digital technology in dentistry. The 3D manufacturing process can be categorized into 2 types: subtractive manufacturing (SM) and additive manufacturing (AM). SM, such as milling is based on cutting away from a solid block of materal. AM, such as 3D printing, is based on adding the material layer by layer. AM enables the fabrication of complex structures that are difficult to mill. In this case, additive manufacturing method was applied to the fabrication of the resin-based complete denture to a 80 year-old patient. During the follow-up periods, the denture using digital method has provided satisfactory results esthetically and functionally.

Comparison of different impression techniques for edentulous jaws using three-dimensional analysis

PURPOSE: The purpose of this study was to compare two novel impression methods and a conventional impression method for edentulous jaws using 3-dimensional (3D) analysis software. MATERIALS AND METHODS: Five edentulous patients (four men and one woman; mean age: 62.7 years) were included. Three impression techniques were used: conventional impression method (CI; control), simple modified closed-mouth impression method with a novel tray (SI), and digital impression method using an intraoral scanner (DI). Subsequently, a gypsum model was made, scanned, and superimposed using 3D analysis software. Mean area displacement was measured using CI method to evaluate differences in the impression surfaces as compared to those values obtained using SI and DI methods. The values were confirmed at two to five areas to determine the differences. CI and SI were compared at all areas, while CI and DI were compared at the supporting areas. Kruskal-Wallis test was performed for all data. Statistical significance was considered at P value .05); the difference was .05). CONCLUSION: The CI, SI, and DI methods were effective in making impressions of the supporting areas in edentulous patients. The SI method showed clinically applicability.

Research advances of clinical applications in repairing surgery for orbital fracture / 眼科新进展

As one of the common type of ocular injuries,orbital fracture can result in enophthalmos,diplopia and infraorbital nerve injury,which affects the physiological function of eyeball.Repairing surgery for orbital fracture should be treated for reconstructing the orbital anatomical structure in case of severe enophthalmos and diplopia,or infraorbital nerve injury.Meanwhile,it's crucial to identify the suitable surgery approach and implants because of the specificity and complexity of the orbit.What a clinician expected most is the ideal prognosis obtained easily with minimal operation complication.Transconjunctival approach should be applied as one of the standard approaches for repairing surgery of orbital fracture,offering good operative field with less complications.Titanium mesh and resorbable materials are the ideal implants at present,for their high level of stable quality and plasticity.More and more applications of 3D-printed rapid prototyping technique can guide the new directions of individualization and precision of repairing surgery for orbital fracture.

Comparison between 3-dimensional cranial ultrasonography and conventional 2-dimensional cranial ultrasonography in neonates: impact on reinterpretation

PURPOSE: The aim of this study was to evaluate impact of 3-dimensional cranial ultrasonography (3DUS) on reinterpretation of cranial ultrasonography images in neonates in comparison with 2-dimensional cranial ultrasonography (2DUS). METHODS: We retrospectively enrolled 50 young infants who simultaneously underwent both 2DUS and 3DUS scanning from February to March 2015. Two pediatric radiologists independently reviewed both scans for overall image quality on a 5-point scale. Five features were evaluated in both scans: the presence of germinal matrix hemorrhage (GMH), intraventricular hemorrhage (IVH), ventriculomegaly (VM), abnormality of periventricular echogenicity (PVE), and focal parenchymal lesions (FL). The concordance rate between the two scanning modes was calculated. The confidence level for each finding on a 3-point scale and the scanning time were compared between the two scanning modes. Interobserver agreement was evaluated using kappa statistics. RESULTS: Both scans demonstrated similar overall image quality in terms of reinterpretation (mean scores for 2DUS and 3DUS, 4.0±0.5 and 4.0±0.7 in reviewer 1, 3.9±0.6 and 4.0±0.8 in reviewer 2, respectively). GMH, IVH, VM, and FL showed perfect concordance, while PVE showed a concordance rate of 91.4% between the two modes by both reviewers. 3DUS was associated with a higher diagnostic confidence in the evaluation of GMH, IVH, and FL than 2DUS (P < 0.05) for both reviewers. For PVE, 3DUS received a significantly higher confidence score than 2DUS from one of the reviewers. The mean scanning time for 2DUS and 3DUS was 92.75 seconds and 36 seconds, respectively. Interobserver agreement for qualitative scoring was almost perfect. CONCLUSION: In reinterpretation, 3DUS showed very high concordance with 2DUS and a similar image quality. 3DUS also increased diagnostic confidence for several image findings and significantly decreased scan time.

Comparison of Three-Dimensional Accuracy between Digital Models Obtained from Impression Scan and Model Scan / 대한치과재료학회지

The purpose of the study is to compare and analyze the accuracy of digital images obtained from impression and stone model with model scanner and to find out clinical effectiveness. A mandibular left first molar composite resin tooth was made for abutment. Digital models were obtained with a same model scanner(Ceramill Map 400, Amann Girrbach, Austria); (1) Fabricated resin model was scanned(Group C). (2) 10 impressions were taken with putty and polyvinyl siloxane, then were scanned (Group I). (3) Type IV stone was poured in each impressions made in step(2) and 10 stone models were scanned(Group S). 3 dimensional super-impositional program (Geomagic control X, 3D Systems, USA) was used to analyze the STL files. Stone model scan(Group S) showed lower deviation than impression scan(Group I) compared to the control group(P < 0.001). Both Group I and Group S showed signs of expansion in the occlusion surface and margin surface while showing contraction in the axial surface. The deviations were smaller in order of occlusal plane, horizontal plane of margin and axial plane. Within the limited boundary of this study, the digital model obtained from stone model scan showed smaller deviation than the digital model obtained from impression scan.