OBJECTIVE: To explore an efficient and automatic method for determining the anatomical landmarks of three-dimensional(3D) mandibular data, and to preliminarily evaluate the performance of the method. METHODS: The CT data of 40 patients with normal craniofacial morphology were collected (among them, 30 cases were used to establish the 3D mandibular average model, and 10 cases were used as test datasets to validate the performance of this method in determining the mandibular landmarks), and the 3D mandibular data were reconstructed in Mimics software. Among the 40 cases of mandibular data after the 3D reconstruction, 30 cases that were more similar to the mean value of Chinese mandibular features were selected, and the size of the mandibular data of 30 cases was normalized based on the Procrustes analysis algorithm in MATLAB software. Then, in the Geomagic Wrap software, the 3D mandibular average shape model of the above 30 mandibular data was constructed. Through symmetry processing, curvature sampling, index marking and other processing procedures, a 3D mandible structured template with 18 996 semi-landmarks and 19 indexed mandibular anatomical landmarks were constructed. The open source non-rigid registration algorithm program Meshmonk was used to match the 3D mandible template constructed above with the tested patient's 3D mandible data through non-rigid deformation, and 19 anatomical landmark positions of the patient's 3D mandible data were obtained. The accuracy of the research method was evaluated by comparing the distance error of the landmarks manually marked by stomatological experts with the landmarks marked by the method of this research. RESULTS: The method of this study was applied to the data of 10 patients with normal mandibular morphology. The average distance error of 19 landmarks was 1.42 mm, of which the minimum errors were the apex of the coracoid process [right: (1.01±0.44) mm; left: (0.56±0.14) mm] and maximum errors were the anterior edge of the lowest point of anterior ramus [right: (2.52±0.95) mm; left: (2.57±1.10) mm], the average distance error of the midline landmarks was (1.15±0.60) mm, and the average distance error of the bilateral landmarks was (1.51±0.67) mm. CONCLUSION The automatic determination method of 3D mandibular anatomical landmarks based on 3D mandibular average shape model and non-rigid registration algorithm established in this study can effectively improve the efficiency of automatic labeling of 3D mandibular data features. The automatic determination of anatomical landmarks can basically meet the needs of oral clinical applications, and the labeling effect of deformed mandible data needs to be further tested.
Humans ; Imaging, Three-Dimensional/methods* ; Mandible/diagnostic imaging* ; Software ; Algorithms ; Anatomic Landmarks/anatomy & histology*

Objective: To explore an automatic landmarking method for anatomical landmarks in the three-dimensional (3D) data of the maxillary complex and preliminarily evaluate its reproducibility and accuracy. Methods: From June 2021 to December 2022, spiral CT data of 31 patients with relatively normal craniofacial morphology were selected from those who visited the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology. The sample included 15 males and 16 females, with the age of (33.3±8.3) years. The maxillary complex was reconstructed in 3D using Mimics software, and the resulting 3D data of the maxillary complex was mesh-refined using Geomagic software. Two attending physicians and one associate chief physician manually landmarked the 31 maxillary complex datasets, determining 24 anatomical landmarks. The average values of the three expert landmarking results were used as the expert-defined landmarks. One case that conformed to the average 3D morphological characteristics of healthy individuals' craniofacial bones was selected as the template data, while the remaining 30 cases were used as target data. The open-source MeshMonk program (a non-rigid registration algorithm) was used to perform an initial alignment of the template and target data based on 4 landmarks (nasion, left and right zygomatic arch prominence, and anterior nasal spine). The template data was then deformed to the shape of the target data using a non-rigid registration algorithm, resulting in the deformed template data. Based on the unchanged index property of homonymous landmarks before and after deformation of the template data, the coordinates of each landmark in the deformed template data were automatically retrieved as the automatic landmarking coordinates of the homonymous landmarks in the target data, thus completing the automatic landmarking process. The automatic landmarking process for the 30 target data was repeated three times. The root-mean-square distance (RMSD) of the dense corresponding point pairs (approximately 25 000 pairs) between the deformed template data and the target data was calculated as the deformation error of the non-rigid registration algorithm, and the intra-class correlation coefficient (ICC) of the deformation error in the three repetitions was analyzed. The linear distances between the automatic landmarking results and the expert-defined landmarks for the 24 anatomical landmarks were calculated as the automatic landmarking errors, and the ICC values of the 3D coordinates in the three automatic landmarking repetitions were analyzed. Results: The average three-dimensional deviation (RMSD) between the deformed template data and the corresponding target data for the 30 cases was (0.70±0.09) mm, with an ICC value of 1.00 for the deformation error in the three repetitions of the non-rigid registration algorithm. The average automatic landmarking error for the 24 anatomical landmarks was (1.86±0.30) mm, with the smallest error at the anterior nasal spine (0.65±0.24) mm and the largest error at the left oribital (3.27±2.28) mm. The ICC values for the 3D coordinates in the three automatic landmarking repetitions were all 1.00. Conclusions: This study established an automatic landmarking method for three-dimensional data of the maxillary complex based on a non-rigid registration algorithm. The accuracy and repeatability of this method for landmarking normal maxillary complex 3D data were relatively good.
Male ; Female ; Humans ; Adult ; Imaging, Three-Dimensional/methods* ; Reproducibility of Results ; Algorithms ; Software ; Tomography, Spiral Computed ; Anatomic Landmarks/anatomy & histology*

Objective: To explore the establishment of an efficient and automatic method to determine anatomical landmarks in three-dimensional (3D) facial data, and to evaluate the effectiveness of this method in determining landmarks. Methods: A total of 30 male patients with tooth defect or dentition defect (with good facial symmetry) who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology from June to August 2021 were selected, and these participants' age was between 18-45 years. 3D facial data of patients was collected and the size normalization and overlap alignment were performed based on the Procrustes analysis algorithm. A 3D face average model was built in Geomagic Studio 2013 software, and a 3D face template was built through parametric processing. MeshLab 2020 software was used to determine the serial number information of 32 facial anatomical landmarks (10 midline landmarks and 22 bilateral landmarks). Five male patients with no mandibular deviation and 5 with mild mandibular deviation were selected from the Department of Orthodontics or Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from June to August 2021. 3D facial data of patients was collected as test data. Based on the 3D face template and the serial number information of the facial anatomical landmarks, the coordinates of 32 facial anatomical landmarks on the test data were automatically determined with the help of the MeshMonk non-rigid registration algorithm program, as the data for the template method to determine the landmarks. The positions of 32 facial anatomical landmarks on the test data were manually determined by the same attending physician, and the coordinates of the landmarks were recorded as the data for determining landmarks by the expert method. Calculated the distance value of the coordinates of facial anatomical landmarks between the template method and the expert method, as the landmark localization error, and evaluated the effect of the template method in determining the landmarks. Results: For 5 patients with no mandibular deviation, the landmark localization error of all facial anatomical landmarks by template method was (1.65±1.19) mm, the landmark localization error of the midline facial anatomical landmarks was (1.19±0.45) mm, the landmark localization error of bilateral facial anatomical landmarks was (1.85±1.33) mm. For 5 patients with mild mandibular deviation, the landmark localization error of all facial anatomical landmarks by template method was (2.55±2.22) mm, the landmark localization error of the midline facial anatomical landmarks was (1.85±1.13) mm, the landmark localization error of bilateral facial anatomical landmarks was (2.87±2.45) mm. Conclusions: The automatic determination method of facial anatomical landmarks proposed in this study has certain feasibility, and the determination effect of midline facial anatomical landmarks is better than that of bilateral facial anatomical landmarks. The effect of determining facial anatomical landmarks in patients without mandibular deviation is better than that in patients with mild mandibular deviation.
Adolescent ; Adult ; Algorithms ; Anatomic Landmarks ; Cephalometry/methods* ; Face/anatomy & histology* ; Female ; Humans ; Imaging, Three-Dimensional/methods* ; Male ; Malocclusion ; Middle Aged ; Orthodontics ; Software ; Young Adult

Objective: Due to its various anatomical variations and numerous branches, the gastrocolic vein trunk (Henle trunk) is the most common site to develop bleeding and other complications in laparoscopic right hemicolectomy for colon cancer. This study aims to investigate the role of ileocolic vein (ICV) joining with Henle trunk, a rare anatomical variation. Methods: A rare case whose ICV was newly found to involve in the formation of Henle trunk during laparoscopic resection of right hemicolon cancer was reported as right gastroepiploic vein+ right colic vein+superior right colic vein+ICV. This anatomical variation was confirmed by multi-slice spiral CT coronal two-dimensional reconstruction of right hemicolon angiography. The literatures about ICV participating in formation of Henle trunk were systematically searched from PubMed, The Cochran Library, CNKI net and Wanfang database, and the occurrence probability and composition of its anatomical variation were analyzed. Results: This was a 47-year-old female patient who underwent laparoscopic right hemicolectomy. When the vessels were dissected during operation, it was found that ICV did not accompany the ileocolic artery, but directly flowed into Henle trunk. Two-dimensional reconstructed CT images of right hemicolon vessels showed that the composition of Henle trunk was rarely varied, which was composed of right gastroepiploic vein, right colonic vein, superior right colonic vein and ICV. Five literatures were enrolled from literature retrieval. A total of 12 cases with ICV participating in the construction of Henle trunk were reported, with a probability of 0.27%-6.31% and 6 forms of the formation of Henle trunk. In this case, Henle trunk was made up of right gastroepiploic vein, right colonic vein, upper right colonic vein and ICV, which was reported for the first time. Conclusions: ICV involving in Henle trunk is a rare vascular variation, and this type of variation should be fully recognized. Careful dissection during operation is necessary to prevent intraoperative bleeding caused by improper operation.
Anatomic Variation ; Colectomy ; Colonic Neoplasms/surgery* ; Female ; Humans ; Laparoscopy ; Mesenteric Veins ; Middle Aged

A clinical information navigation system based on 3D human body model is designed. The system extracts the key information of diagnosis and treatment of patients by searching the historical medical records, and stores the focus information in a predefined structured patient instance. In addition, the rule mapping is established between the patient instance and the three-dimensional human body model, the focus information is visualized on the three-dimensional human body model, and the trend curve can be drawn according to the change of the focus, meanwhile, the key diagnosis and treatment information and the original report reference function are provided. The system can support the analysis, storage and visualization of various types of reports, improve the efficiency of doctors' retrieval of patient information, and reduce the treatment time.
Diagnosis, Computer-Assisted ; Humans ; Medical Informatics Applications ; Models, Anatomic ; Software

OBJECTIVE: To reconstruct a three-dimensional model of female urinary system based on magnetic resonance imaging (MRI) and tomography angiography (CTA) data. METHODS: MRI and CTA datasets were collected from 20 patients in our department in 2018 for reconstructing 3D models of the bladder urethra in resting state using Mimics19.0 software combined with engineering software. The metric parameters of the bladder urethra were analyzed in the reconstructed 3D model. RESULTS: The bladder and urethra were successfully reconstructed using 10 MRI datasets, and the kidney, ureter and bladder were reconstructed using 10 CTA datasets. Using engineering software, we measured a number of cysto-urethral geometric parameters, including the cysto-urethral posterior angle (151.1±17.9°), beta angle (137.3±14.0°), urethral pubic angle (47.8± 12.1°), urethral tilt angle (21.5±7.3°), alpha angle (83.8±13.8°), the posterior pubic space (15.3±3.0 mm), and the urethral striated muscle thickness (2.6±0.6 mm). CONCLUSIONS Three-dimensional reconstruction of the anatomical model of the human urinary system provides a platform for studying the fine anatomy of the female urinary system and allows measurement of multiple parameters to better understand the functional differences of the bladder and urethra in different populations.
Female ; Humans ; Imaging, Three-Dimensional ; Magnetic Resonance Imaging ; Models, Anatomic ; Muscle, Skeletal ; Tomography, X-Ray Computed ; Urethra ; diagnostic imaging ; Urinary Bladder ; diagnostic imaging

OBJECTIVE: To reconstruct a three-dimensional model of female urinary system based on magnetic resonance imaging (MRI) and tomography angiography (CTA) data. METHODS: MRI and CTA datasets were collected from 20 patients in our department in 2018 for reconstructing 3D models of the bladder urethra in resting state using Mimics19.0 software combined with engineering software. The metric parameters of the bladder urethra were analyzed in the reconstructed 3D model. RESULTS: The bladder and urethra were successfully reconstructed using 10 MRI datasets, and the kidney, ureter and bladder were reconstructed using 10 CTA datasets. Using engineering software, we measured a number of cysto-urethral geometric parameters, including the cysto-urethral posterior angle (151.1±17.9°), beta angle (137.3±14.0°), urethral pubic angle (47.8± 12.1°), urethral tilt angle (21.5±7.3°), alpha angle (83.8±13.8°), the posterior pubic space (15.3±3.0 mm), and the urethral striated muscle thickness (2.6±0.6 mm). CONCLUSIONS Three-dimensional reconstruction of the anatomical model of the human urinary system provides a platform for studying the fine anatomy of the female urinary system and allows measurement of multiple parameters to better understand the functional differences of the bladder and urethra in different populations.
Female ; Humans ; Magnetic Resonance Imaging ; Models, Anatomic ; Tomography, X-Ray Computed ; Urethra ; Urinary Bladder

Surgeons need to understand the effects of the nasal cartilage on facial morphology, the function of both soft tissues and hard tissues and nasal function when performing nasal surgery. In nasal cartilage-related surgery, the main goals for clinical research should include clarification of surgical goals, rationalization of surgical methods, precision and personalization of surgical design and preparation and improved convenience of doctor-patient communication. Computational technology has become an effective way to achieve these goals. Advances in three-dimensional (3D) imaging technology will promote nasal cartilage-related applications, including research on computational modelling technology, computational simulation technology, virtual surgery planning and 3D printing technology. These technologies are destined to revolutionize nasal surgery further. In this review, we summarize the advantages, latest findings and application progress of various computational technologies used in clinical nasal cartilage-related work and research. The application prospects of each technique are also discussed.
Computer Simulation ; Face ; Humans ; Models, Anatomic ; Nasal Cartilages ; Nasal Septum ; surgery ; Nose ; surgery ; Printing, Three-Dimensional ; Rhinoplasty ; trends

The xiphoid process of the sternum lies in the epigastric region and functions to serve as an attachment point for vital muscles that aid in respiration. With the xiphoid process extending as the most inferior portion of the sternum, variable morphology is widely observed. During a routine dissection of a 44-year-old Caucasian male cadaver, we discovered a hook-shaped, elongated xiphoid process that protruded dorsally. Potential clinical significance can arise leading to misdiagnosis of the hook-shaped xiphoid process as an epigastric mass during imaging. Though various variations of xiphoid process have been well documented, knowledge of a hook-shaped xiphoid process orientated dorsally remains scarce. Herein, this case study provides clinicians, surgeons, and radiologists a rare anomaly of the xiphoid process in order to further the knowledge of morphological variations of the xiphoid to prevent misdiagnosis and surgical complications.
Adult ; Anatomic Variation ; Cadaver ; Diagnostic Errors ; Humans ; Male ; Muscles ; Respiration ; Sternum ; Surgeons

Congenital heart disease (CHD) is the most common birth defect at present. In recent years, the application of 3D printing in the diagnosis and treatment of CHD has been widely recognized, which presents CHD lesions in 3D solid model and provides a better understanding of the anatomy of CHD. In the future, 3D printing technology would improve the surgical proficiency, shorten the operation time, reduce the occurrence of perioperative complications, and create more personalized cardiovascular implants, therefore promote the precision of diagnosis and treatment for congenital heart disease. This article reviews the application of 3D printing technology in preoperative planning, intraoperative navigation and personalized implants of CHD, in surgical training and medical education, as well as in promoting doctor-patient communication and better understanding their condition for patients.
Heart Defects, Congenital ; Humans ; Models, Anatomic ; Preoperative Care ; Printing, Three-Dimensional