Application of 3D-CT simulation image in the description of gastric artery variation to guide laparoscopic total gastrectomy / 中华胃肠外科杂志

Objective: Anatomic variations in the perigastric vessels during laparoscopic radical gastrectomy often affect the operator's judgment and prolong the operation time, and even cause accidental injury and surgical complications, and hence the safety and quality of the operation cannot be ensured. In this study, multiple slice CT was reconstructed by 3-dimensional CT simulation software (3D-CT), and 3D-CT images were used to describe the variation of celiac trunk and splenic artery before surgery. The guiding role of the different variation of vessels was analyzed for laparoscopic total gastrectomy+D2 lymph node dissection (LTG+D2LD). Methods: A retrospective cohort study was conducted. Case inclusion criteria: (1) Gastric cancer was at an advanced stage. All the patients were preoperatively examined by digestive endoscopy and 64-row enhanced CT scan, and were histopathologically diagnosed with gastric adenocarcinoma. (2) 3D-CT simulation images were reconstructed to guide the operation. (3) LTG+D2LD surgery was performed by the same surgical team. (4) Clinical data were complete, and all the patients had signed the informed consent. From 2014 to 2018, 98 patients with gastric cancer at the Gastrointestinal Surgery Department of Henan Provincial People's Hospital were enrolled. According to the Adachi classification, celiac trunk variation was divided into common type (Adachi type I) and rare type (Adachi type II-VI). According to the Natsume classification, splenic artery was classified into "flat type" and "curved type". Based on 3D-CT simulation images, variation of celiac trunk and splenic artery was described, and the differences in operation time, intraoperative blood loss and the number of postoperative retrieved lymph nodes were compared between groups with different types of arterial variation. Results: For celiac trunk, common type was found in 84 cases (86%) and rare type was found in 14 cases, including 6 cases (6%) of type II, 2 cases (2%) of type III, 2 cases (2%) of type IV, 3 cases (3%) of type V, 1 case (1%) of type VI. No other types were found. There were no statistically significant differences in clinical characteristics and number of retrieved lymph nodes between patients of the common type group and rare type group (all P>0.05). Compared with common type patients, those of rare type had longer operative time [(321.1±29.0) minutes vs. (295.1±46.5) minutes, t=2.081, P=0.040] and more intraoperative blood loss (median: 66.0 ml vs. 32.0 ml, Z=-4.974, P=0.001). For splenic artery, 41 patients (42%) were flat type and 57 patients (58%) were curved type. There were no statistically significant differences between the two groups in terms of clinical characteristics, intraoperative blood loss, operative time and number of retrieved lymph nodes (all P>0.05). Conclusions: The method of describing the variation in the perigastric vessels by 3D-CT simulation has certain clinical value in laparoscopic radical gastrectomy. The duration of LTG+D2LD is prolonged and the intraoperative blood loss is increased with the variation of celiac trunk, while the variation of splenic artery has no effect on LTG+D2LD.

Application of 3D-CT reconstruction technology to predicting difficult airway in patients with odontogenic infections / 上海交通大学学报（医学版）

Objective: To evaluate the application of 3D-CT airway reconstruction images to predicting difficult airway in patients with odontogenic infections. Methods: A retrospective analysis was performed on patients with odontogenic infections who were treated by incision and drainage under general anesthesia at Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from August 2017 to July 2019, and patients who were evaluated as difficult airway receiving awake tracheal intubation were selected as the case group (n=27). From the "Hospital Inpatient System", patients who were evaluated as non-difficult airway receiving fast induction were selected as the control group (n=27). Maxillofacial CT scans of all the patients were collected. The Dolphin Imaging software version 11.9 Premium was used to perform 3D-CT reconstruction of the airway. The upper airway was divided into oropharynx and hypopharynx, and the oropharynx was divided into velopharynx and glossopharyngeal. The indicators such as airway volume, median sagittal area, minimal cross-sectional area, and thickness of pharyngeal soft tissue were collected. The indicators of the difference between the two groups were compared and selected. Logistic re-gression analysis was conducted to investigate the association of these factors with difficult airway. Results: The volume of velopharynx and hypopharynx, the median sagittal area of velopharynx, oropharynx and hypopharynx, the mean cross-sectional area of velopharynx and hypopharynx, the minimal cross-sectional area and its lateral dimension of oropharyngeal of patients in the case group were significantly smaller than those of the controls (P<0.05). Thickness of pharyngeal soft tissue in the most inferior-anterior point of the second and the third cervical vertebrae of patients in the case group was significantly higher than that of the controls (P<0.05). The Logistic regression analysis showed that the median sagittal area of velopharynx, oropharynx and hypopharynx, the volume and mean cross-sectional area of hy-popharynx, and thickness of pharyngeal soft tissue in the most inferior-anterior point of the second and the third cervical vertebrae of patients were related to difficult airway in patients with odontogenic infections (P<0.05). Conclusion: Airway 3D-CT reconstruction can clearly show the airway anatomy of patients with odontogenic infections. The median sagittal area of pharynx, the volume and mean cross-sectional area of hypopharynx, and thickness of pharyngeal soft tissue in the most inferior-anterior point of the second and the third cervical vertebrae may will be used as predictors of difficult airway in patients with odontogenic infections.

Morphologic and morphometric analysis of glenoid cavity of human scapula

Background: To study the morphometry and morphology of glenoid cavity of dried scapula bone and in CT scan of glenoid cavity. The present study aimed at calculating three dimensions i.e. vertical diameter, horizontal diameter of the upper segment and horizontal diameter of the lower segment of the glenoid cavity and describing the incidence of its different shapes.Methods: This study was done on 100 dry, unpaired adult human scapulae of unknown sex. 50 scapulae belongs to right side and 50 scapulae belongs to left side obtained from Department of Anatomy, SRM Medical College and Research Institute. The above mentioned diameters are measured using Vernier caliper and the mean dimensions are calculated, morphological variations are studied. 3D CT images of scapulae, obtained from Department of Radiology, SRM Medical college and Hospital, Potheri, were also analysed.Results: In the current study, various dimensions and incidence of various shapes of glenoid cavity were measured. The incidence of both pear and inverted comma shape in right side is greater than in left whereas the incidence of oval shape in left side is greater than right side. The SI diameter of right glenoid is greater than the left, which is statistically significant. The Antero-posterior diameters (AP-1, AP-2, AP-3) of right glenoid is greater than the left, but not statistically significant.Conclusions: The knowledge of the above said variations of glenoid cavity is important in manufacturing the glenoid component of shoulder prosthesis, repair of Bankart’s lesion, procedures like posterior glenoid osteotomy.

Percutaneous left ventricular transapical access guided by cardiac 3D CT angiography combined with echocardiography / 中国胸心血管外科临床杂志

@#Objective    To investigate the reliability and safety of the technique of percutaneous left ventricular transapical access guided by cardiac three dimensional CT angiography (3D-CTA) combined with echocardiography applied in structural heart defects. Methods    The clinical data of 9 patients (7 males and 2 females with a median age of 50 years ranging from 43 to 64 years) with paravalvular leaks closed by percutaneous left ventricular transapical access in West China Hospital, from April 2015 to August 2018, were retrospectively analyzed. We applied preoperative cardiac 3D-CTA to define the puncture site and trace, which was established by combining with real-time guidance of transesophageal echocardiography (TEE/3D-TEE), and an occluder was deployed at the apical access point for hemostasis with real-time guidance of transthoracic echocardiography (TTE). Results    The puncture needles were successfully introduced into the left ventricular cavity at one time in all patients without injury of lung tissue, coronary artery or papillary muscle. There was no occluder displacement or apex bleeding. One patient developed pleural effusion caused by intercostal artery injury. Conclusion    That cardiac 3D-CTA is used to define puncture sites and trace with advantages of simplicity and repeatability. A safe access and secure exit of left ventricle can be achieved by combining with real-time guidance of echocardiography. There are acceptable technology-related complications.

Reconstrucción del ligamento patelofemoral medial (LPFM) con autoinjerto cuadricipital y uso de TAC 3D preoperatorio para establecer punto anatómico femoral / Medial patellofemoral ligament reconstruction with a quadriceps autograft and using a pre-operative 3-d ct scan to locate the femoral anatomical point

Introducción En los últimos años ha cobrado importancia la reconstrucción del LPFM. La técnica más utilizada es con autoinjerto de tendones isquiotibiales. En algunas series los reportes de complicaciones son mayores al 26%. Este trabajo pretende demostrar la utilidad del autoinjerto del cuádriceps para la reconstrucción del LPFM, sin túneles rotulianos y sin el uso de fluoroscopia intraoperatoria. Materiales y métodos Se incluyeron pacientes con historia clínica de al menos dos episodios de luxación. Se tomaron en todas los pacientes serie radiográfica, TAC axial rótulas, TAC 3D y RNM. Se obtuvo registro de manera retrospectiva de puntuaciones en las escalas de Lysholm, Tegner y Kujala en el posoperatorio con controles a los 6,12 y 18 meses. Resultados Cumplieron con los criterios de selección 24 pacientes, 16 mujeres y 8 hombres, edad promedio de 23 años.En nuestro estudio se observó la mejoría de puntuaciones en las escalas de Lysholm, Tegner y Kujala en el posoperatorio con controles a los 6,12 y 18 meses. Sin presentarse nuevos episodios de luxación rotuliana u otras complicaciones relevantes. Hubo un retorno en todos los casos a la actividad deportiva. Discusión Este estudio reafirma que el tendón cuadricipital es un injerto que reproduciendo mejor la anatomía del LPFM, presenta cifras comparables o mejores funcionalmente con los otros injertos utilizados en la actualidad. Con el protocolo preoperatorio de TAC3D se ha conseguido identificar en forma individual y con la especificidad anatómica de cada paciente, al tubérculo aductor y epicóndilo medial, dando mayor certeza en la ubicación anatómica de la inserción femoral LPFM. Con las ventajas adicionales de disminuir el tiempo quirúrgico, y evitar radiación innecesaria en el equipo quirúrgico.

Background The reconstruction of the medial patellar-femoral ligament (MPFL) has become increasingly important in recent years. The most used technique is a hamstring tendons autograft. Complications of greater than 26% have been reported in some series. The aim of this study is to demonstrate the use of quadriceps autograft for the reconstruction of the MPFL, without patellar tunnels and without the use of intraoperative fluoroscopy. Methods A Case Series study was performed. Patients with a clinical history of at least two episodes of dislocation were included. A series of x-rays, axial Computed Tomography (CT), patellae, 3D CT, and MR image were taken in all patients. Scores on the Lysholm, Tegner, and Kujala scales were used in the postoperative period, with controls at 6, 12 and 18 months being recorded Results A total of 24 patients, 16 women and 8 men, with a mean age of 23 years, met the selection criteria. An improvement was observed in the scores on the Lysholm, Tegner, and Kujala scales in the postoperative period, with controls at 6, 12, and 18 months. No new episodes of patellar dislocation or other relevant complications were observed. There was a return to sports activity in all cases. Discussion This study reaffirms that the quadriceps tendon is a graft that reproduces the anatomy of the MPFL better, shows figures comparable or functionally better than with the other grafts used at present. Using the preoperative protocol of 3-D CT scans, the adductor and medial epicondyle tubules have been identified individually and with the anatomical specificity of each patient, giving greater certainty in the anatomical location of the MPFL femoral insert. This also has the additional advantages of decreasing surgical time, and avoiding unnecessary radiation in the surgical team.

Nasal Bone 3 Dimentional Computer Tomography Guided Tailored Osteotomy of the Bony Deviated Nose / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Correction of deviated nose is considered one of the most difficult and serious surgical operations in rhinoplasty. The correction of bony deviation, in particular, requires osteotomy. Although there are individual differences in the shapes or features of bony deviations of each patient, the techniques of osteotomy are limited. Therefore, for proper correction of bony deviation, it is necessary to set up a precise pre-surgical plan. SUBJECTS AND METHOD: We categorized 187 patients with bony deviated nose into 5 types based on the analysis of preoperative nasal bone 3D computer tomography, and studied surgical method for each type. RESULTS: Of 187 patients, 92 (49%) patients are categorized into type I, 62 (36%) patients into type II, 12 (6%) patients into type III, 2 (1%) patients into type IVa, 7 (4%) patients into type IVb and 7 (4%) patients into type V. Only did eight patients (5%) undergo revision surgery due to unsuccessful outcomes. Major complications like infection, abscess, arteriovenous fistula, epiphora, and saddle deformation did not occur at all. CONCLUSION: Preoperative planning under the analysis and categorization using 3D CT is considered helpful for the precise and individualized surgery in corrective rhinoplasty.

A comparative study of Conventional and CT based planning of Target volumes and organs at risk in Intra cavitary brachytherapy for Carcinoma of cervix

Introduction: Cervical cancer is the third most common malignancy in women worldwide, and it remains the leading cause of cancer related deaths in women in developing countries. In the management of cervical cancer, both intracavitary brachytherapy (ICBT) and external radiotherapy (ERT) are essential as they deliver a high dose to the primary tumor and low doses to adjacent organ. The dose can be delivered either by conventional orthogonal radiograph mapping or by the 3- dimensional computed tomography mapping. In the present study, we have compared both the techniques. Aim and objectives: To compare intracavitary brachytherapy (ICBT) planning methods for cervical cancer based on orthogonal radiographs (conventional plan) and computed tomography sections (CT plan). Materials and methods: This was a prospective study, conducted in the department of Radiotherapy, MNJ Institute of Oncology and Regional Cancer Centre, over a period of two years from November 2012 to November 2014. The study consisted of total 25 registered patients having confirmed diagnosis of Squamous cell carcinoma of cervix. All the patients underwent conventional and CT planning for brachytherapy. One arm received the conventional plan of radiotherapy while the other arm received computed tomography (CT) based plan. Radhika Rani, R. Srikanth. A comparative study of Conventional and CT based planning of Target volumes and organs at risk in Intra cavitary brachytherapy for Carcinoma of cervix. IAIM, 2016; 3(9): 200-209. Page 201 Results: The patient age ranged from 35 to 65 years. The mean age was 47 years. The results of the study demonstrates that CT-guided brachytherapy planning is superior in terms of both conformity of target coverage and evaluation of OARs .Although this superiority was clear for small GTVs, for large GTVs both the conventional and CT-Plans had the drawbacks of inadequate target coverage and /or excessive radiation doses to normal organs. Conclusions: The conventional plan with the point A calculation relies on reference points on orthogonal films ,not tumor volumes defined on CT, which may cause underestimation of tumor doses. Likewise, the calculation of rectum and bladder doses made with ICRU reference points, not with bladder and rectal volumes may not reflect the actual organ doses. To overcome such problems, 3D CT-guided brachytherapy treatment planning is recommended.

Analysis of Femoral Tunnel Position Targeted at Bifurcate Ridge Using Anteromedial Portal Technique in Anatomic Anterior Cruciate Ligament Reconstruction / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to analyze the position of the 10-mm-sized femur tunnel drilled aiming for the bifurcate ridge using anteromedial portal technique with 'Figure of 4 position' by 3-dimensional computed tomography (3D-CT) reconstruction images after anatomic anterior cruciate ligament (ACL) reconstruction and to evaluate it's propriety. MATERIALS AND METHODS: Out of 35 patients who underwent anatomic ACL reconstruction from March 2012 to February 2013, 32 patients who undergone postoperative 3D-CT scans were included in this study retrospectively. Medial surface of the lateral femoral condyle was reconstructed using Mimics, and then the position of the femoral tunnel was evaluated using the Bernard quadrant method and the results were compared with those of published literatures. The mean age of the patients was 32.6 years old. There were 25 cases of double-bundle ACL reconstruction with one femoral-two tibial tunnel. There were 7 cases of single bundle ACL reconstruction with one femoral-one tibial tunnel. RESULTS: The mean distance of the femoral tunnel center was 32.2%+/-2.9% (range, 27.4%-37.6%) along the line parallel to the Blumensaat's line from the posterior condylar surface and 46.7%+/-2.3% (range, 43.5%-51.1%) along the line perpendicular to the Blumensaat's line from the roof of the notch. In comparison with the results of published literature, although the center of the femoral tunnel was presented in the femoral footprint, it was located slightly more shallow and inferior than the center of the ACL footprints. CONCLUSION: The bifurcate ridge may be a good anatomic landmark when making a 10-mm-sized single femoral tunnel in 'Figure of 4 position' using the anteromedial portal technique.

Evaluation of the Forearm Dominancy Artery for Invasive Vascular Procedure with 3D-CT Angiography

The aim of this study was to evaluate the vascular dominance in the forearm as a factor in determining the choice of invasive vascular procedures in arteries of the forearm, using 3D-computerized tomography (3D-CT) angiographies of 92 forearms. The diameters of the ulnar and radial arteries were measured just distal to the bifurcation of the brachial artery, at the midpoint between the bifurcation and the wrist, and at the wrist crease. In 79 cases, the ulnar artery was larger than the radial artery after the bifurcation of the brachial artery. However, no statistically significant difference was observed at either the mid-forearm or the wrist crease. In the remaining 13 cases, the diameter of the radial artery was larger or the same as that of the ulnar artery after the bifurcation, but at the more distal sites no regular pattern could be detected. The findings suggest that 3D-CT angiography offers valuable preoperative details of the forearm vessels for cases requiring invasive vascular procedures on the forearm.

Application of femoral neck anteversion′s correction in the treatment of children′s developmental dysplasia of the hip / 重庆医学

Objective To discuss application of femoral neck anteversion′s correction in the treatment of children′s developmen-tal dysplasia of the hip .Methods 98 children diagnosed DDH from Jan 2006 to Jan 2010 were treated and followed up ranging from 12 to 48 months ,average 32 months .Before the operations ,FNA index were evaluated by X-ray and thin slice hip joint scan and 3D reconstruction to guide the rotary osteotomy .After the operations ,FNA index were rechecked .Results According to Mckay′s clas-sification ,clinical assessment was performed .84 hips were evaluated as excellent (73 .68% ) ,20 hips as good(17 .55% ) ,10 hips as acceptable(8 .77% ) ,and no poor hip (0% ) was reported .FNA decreased averagely 16 .3° ± 2 .0° .FNA had significant difference with themselves before the operations(P0 .05) .Conclusion The change of FNA is one of the most important pathological changes .FNA′s correction is one of the most valuable to guarantee success operation .

Plastinated fetus: 3D CT scan (VRT) evaluation.

Objective: The intent of this study was to evaluate the effect of plastination on the morphology and structure of stored organs, to find out how much accuracy a plastinated specimen has, and to look into the changes that occurred because of plastination. Materials and Methods: A human fetus of gestational age 24 weeks was plastinated, and 3D CT scan evaluation of the fetus was done. Results: The results showed normal, well-defined, clearly identifiable organs, with no alteration in morphology and structure of organs. Conclusion: In our opinion, plastinated specimens are better way of visualization of morphology and structure of stored organs, which is a useful tool for teaching as well as for research purposes.

Measurement Discrepancy of Sagittal Parameters between Plain Radiography and 3D Computed Tomography in Thoracolumbar and Lumbar Fractures / 대한정형외과학회잡지

PURPOSE: For decision making in the management of vertebral fractures such as operation or not, sagittal parameters like Cobb angle and wedge compression ratio are important. Plain radiography had been the only image tool for measuring such parameters until 3D computed tomography (CT) became popular recently. In this study, we investigated the measurement discrepancy between plain radiography and 3D CT. MATERIALS AND METHODS: Plain radiography and 3D CT of 45 thoracolumbar and lumbar fracture patients (male=21, female=24) were evaluated. We measured sagittal angle and vertebral height on lateral radiography and sagittal CT. Sagittal angle was measured between the upper body and lower body of fractured vertebrae. Anterior and posterior heights were measured to assess anteriorposterior (AP) wedge ratio. RESULTS: The sagittal angle of plain radiography (13.1+/-14.3degrees) was significantly larger than that of 3D CT (8.2+/-13.0degrees) by 4.9degrees (p<0.001). AP wedge ratio of plain radiography was on average 65+/-17%, which was significantly lower than the 3D CT (73+/-17%) by 8% (p<0.001). The severer the initial kyphotic deformity, the more discrepancy of results between the two methods was observed. CONCLUSION: Significant discrepancy was observed in sagittal features of fractured vertebra between plain radiography and 3D CT. Measured values of plain radiography showed more kyphotic features of the fractured body.

The Importance of Preoperative Epicardial Imaging by Three-Dimensional Computed Tomography in Off-pump Cardiac Surgery for Coronary Artery Fistula with Coronary Aneurysm / 日本心臓血管外科学会雑誌

We surgically treated coronary artery fistula with 2 aneurysmal formations without cardiopulmonary bypass. Preoperative epicardial imaging suggested that ligation of both inflow and outflow of the coronary artery fistula was feasible. Preoperative understanding of anatomical relationships by 3D-CT imaging can be very useful in selection of surgical procedures.

Open Repair of Acute Tibial Avulsion Injury of Posterior Cruciate Ligament: Clinical Outcomes and Usefulness of Preoperative 3-D CT / 대한정형외과학회잡지

PURPOSE: To evaluate the clinical outcome of open repair of acute tibial posterior cruciate ligament (PCL) tibial avulsion injury using the posteromedial approach, and to examine the usefulness of pre-operative 3D-computed tomography (CT) imaging. MATERIALS AND METHODS: From July 2004 onwards, among the 33 patients with acute tibial avulsion injury of the PCL, 22 patients were available for a 1-year follow-up. Patients underwent internal fixation using screws, pullout sutures or staples through the posteromedial approach. Clinical evaluations were performed using the posterior drawer test, posterior drawer stress x-ray, range of motion and Tegner score. In addition, size of the fragment, visibility, comminution, displacement and presence of extension were studied and were compared to the pre-operative X-ray and 3D-CT imaging. RESULTS: Four cases demonstrated 10-degree restriction in flexion and 1 case demonstrated 10-degree restriction in extension compared to the unaffected side. Except for the 2 cases which had Grade I posterior instability on the posterior drawer test, the results of the post-operative joint stability were negative and the posterior drawer stress X-ray using the Telos device showed an average of 0.57+/-0.4 mm. Like the average pre-operative Tegner score of 6.7+/-0.9, the Tegner score was restored to 6.2+/-0.7 (p>0.05) at the last follow-up. 3D-CT showed an improved accuracy in visibility (55.6%), comminution (50%) and displacement (44.4%) compared to the simple X-ray. CONCLUSION: The acute tibial avulsion injury treated with the appropriate internal fixation through the posteromedial approach based on the fracture size demonstrated exellent outcomes. The pre-operative 3D-CT was useful for identifying the fracture pattern and choosing the appropriate internal fixation.

Tessier No. 2 Oblique Facial Cleft Not Associated with Cleft Lip or Palate: a Case Report

Comparison of the observer reliability of cranial anatomic landmarks based on cephalometric radiograph and three-dimensional computed tomography scans

INTRODUCTION: Accurate diagnosis and treatment planning are very important for orthognathic surgery. A small error in diagnosis can cause postoperative functional and esthetic problems. Pre-existing 2-dimensional (D) chephalogram analysis has a high likelihood of error due to its intrinsic and extrinsic problems. A cephalogram can also be inaccurate due to the limited anatomic points, superimposition of the image, and the considerable time and effort required. Recently, an improvement in technology and popularization of computed tomography (CT) provides patients with 3-D computer based cephalometric analysis, which complements traditional analysis in many ways. However, the results are affected by the experience and the subject of the investigator. MATERIALS AND METHODS: The effects of the sources human error in 2-D cephalogram analysis and 3-D computerized tomography cephalometric analysis were compared using Simplant CMF program. From 2008 Jan to 2009 June, patients who had undergone CT, cephalo AP, lat were investigated. RESULTS: 1. In the 3 D and 2 D images, 10 out of 93 variables (10.4%) and 11 out 44 variables (25%), respectively, showed a significant difference. 2. Landmarks that showed a significant difference in the 2 D image were the points frequently superimposed anatomically. 3. Go Po Orb landmarks, which showed a significant difference in the 3 D images, were found to be the artificial points for analysis in the 2 D image, and in the current definition, these points cannot be used for reproducibility in the 3 D image. CONCLUSION: Generally, 3-D CT images provide more precise identification of the traditional cephalometric landmark. Greater variability of certain landmarks in the mediolateral direction is probably related to the inadequate definition of the landmarks in the third dimension.

Comparison of midsagittal reference plane in PA cephalogram and 3D CT / 대한치과교정학회지

OBJECTIVE: The aim of this study is to find the most helpful midsagittal reference plane for diagnosis in PA cephalometry compared with 3D CT. METHODS: The subjects consisted of 25 adults who showed no facial asymmetry by gross inspection. 3D CT and posteroanterior cephalogram of the subjects were taken. To find the most helpful midsagittal reference plane in PA cephalometry, we considered five kinds of midsagittal planes from which the distances to five landmarks were measured and compared the result with that of 3D CT. The midsagittal plane for 3D CT was determined by the landmarks Nasion, Sella and Basion. RESULTS: PA measurements using the midsagittal reference plane on a perpendicular plane lying through the midpoint of the right and left latero-orbitales was closest to those of 3D CT. CONCLUSIONS: It was considered that latero-orbitale perpendicular could be used as the helpful midsagittal reference plane to assess facial asymmetry in PA cephalometry.

The structural change in the hyoid bone and upper airway after orthognathic surgery for skeletal class III anterior open bite patients using 3-dimensional computed tomography / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to investigate the structural changes of the hyoid bone and upper airway after orthognathic surgery for skeletal class III anterior open bite patients, and make comparisons with normal occlusion. METHODS: Pre- and post-operative computed tomography (CT) examinations were performed on 12 skeletal class III anterior open bite patients who were treated with mandibular setback osteotomy. Using the V-works 4.0(TM) program, 3-dimensional images of the total skull, mandible, hyoid bone, and upper airway were evaluated. RESULTS: In the Class III openbite group, the hyoid bone were all positioned anteriorly, compared to the Normal group (p < 0.05). The angle between the hyoid plane and mandibular plane in the Class III openbite group before surgery was greater than in the Normal group (p < 0.05), and the difference increased after surgery (p < 0.01). In the Class III openbite group, the volume of the upper airway decreased after surgery (p < 0.001) and the volume of the upper airway was smaller than the Normal group before and after surgery (p < 0.001). CONCLUSIONS: The narrow upper airway space in skeletal Class III openbite patients decreased after mandibular setback osteotomy. This may affect the post-surgical stability.

Analysis of masseter muscle in facial asymmetry before and after orthognathic surgery using 3-dimensional computed tomography / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to understand the differences in masseter muscle (MM) between the shifted and non-shifted sides in facial asymmetry patients, and the changes shown by MM after mandibular surgery. METHODS: Pre- and post-operative CT scans were performed on 12 Class III patients with facial asymmetry who were treated by intraoral vertical ramus osteotomy and 10 subjects with normal occlusion. Using the V-works 4.0 program (Cybermed, Seoul, Korea), 3-dimensional images of the mandible, and MM were reconstructed, and evaluated. RESULTS: In the asymmetry group, the MM angle between the shifted and non-shifted sides was only significantly different (p < 0.05). Compared with normal occlusion, the asymmetry group showed a significantly smaller volume and maximum cross-sectional area in both sides of MM (p < 0.05). After mandibular surgery, the angle of MM (p < 0.01) and differences in angle between the shifted and non-shifted sides of MM (p < 0.05) were significantly decreased. The thickness in the maximum cross-sectional area was significantly increased (p < 0.01). After surgery, MM in facial asymmetry patients was similarly changed to those in the normal occlusion group except for widths. CONCLUSIONS: MM in facial asymmetry was definitely different from those in normal occlusion. However, this study suggests that MM changed symmetrically in conjunction with the mandible after proper mandibular surgery.

The Availability of Three-Dimensional Computed Tomography Reconstructions on the Classification and Treatment Plan of Distal Radius Fractures

PURPOSE: The purpose of this study is to determine whether the three-dimensional computed tomography (3D-CT) images would increase the reliability of fracture classification and influence treatment plan of distal radius fractures. MATERIALS AND METHODS: Four independent observers evaluated radiographic images of thirty patients with distal radius fractures. The fracture classification has been performed based on (1) AO classification, (2) Fernandez classification, (3) Frykman classification. And then treatment plan was planned based on (1) closed reduction with Sugar-tong splint, (2) closed reduction with pinning, (3) closed reduction with external fixator, (4) open reduction with plate (volar approach), (5) open reduction with plate (dorsal approach). Two rounds of evaluation were compared regarding: (1) simple radiographs alone, and (2) simple radiographs and 3D-CT together two weeks after that. This cycle was then repeated to assess intraobserver reliability. RESULTS: 3D-CT improved the intraobserver and interobserver reliability regarding the fracture classification and treatment plan. And the addition of 3D-CT to simple radiographs influenced treatment recommendations, resulting in a significantly greater number of decisions for an open approach (p<0.05, McNemar test). CONCLUSIONS: 3D-CT is a reliable tool of fracture classification and improves treatment plan of distal radius fractures.