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*

BACKGROUND: In cervical anterior approach, transverse skin incision is preferred due to cosmetic reasons. Precise skin incision is required to reach the surgery segment while minimizing soft tissue injury. Skin incision site is frequently identified using C-arm fluoroscopy or the carotid tubercle. Accordingly, this study was conducted to investigate the efficacy of skin incision using the carotid tubercle as a marker. METHODS: This study was retrospectively conducted on 114 patients who underwent anterior cervical surgery by the same surgeon from April 2004 to June 2012. The rate of the appropriate insertion of K-wire, which was inserted into the disc after anterior approach, into the surgery segment was compared between 62 patients where skin incision site was identified using C-arm fluoroscopy before skin incision and 52 patients where skin incision site was identified using carotid tubercle palpitation before surgery. RESULTS: The needle was shown to have been inserted into the planned site in 106 patients out of the total 114 patients. The appropriate insertion of the needle was shown in 59 patients of group I (95.2%) and in 47 patients of group II (90.4%). Although the success rate was higher in group I than group II, it was statistically insignificant. The success rate of one-segment surgery was shown to be 89.7% in group I and 82.6% in group II. Although the success rate was higher in group I than group II, it was statistically insignificant. The success rate of two-segment surgery was shown to be 100% in group I, and 96.4% in group II due to one case of the failure at C3-4 and C5-6. The success rate of three- and four-segment surgeries was shown to be 100% in both groups. CONCLUSIONS: The identification of skin incision site via carotid tubercle palpation was useful for surgeries involving two or more segments. Furthermore, it could be useful for one-segment surgery if surgical site is identified using vertebral body or soft tissues such as longus collis rather than insertion into the disc.
Adult ; Anatomic Landmarks/anatomy & histology/radiography ; Cervical Vertebrae/*anatomy & histology/radiography/*surgery ; Female ; Fluoroscopy/*methods ; Humans ; Male ; Middle Aged ; Palpation/*methods ; Retrospective Studies

OBJECTIVETo investigate the morphological features of the perforator from the first plantar metatarsal artery, so as to provide anatomic basis for the reconstruction of soft-tissue defects of the forefoot.

METHODSThe first metatarsophalangeal joint was chosen as the landmark on 30 human cadaveric feet prefused with red latex. The following contents were observed under surgical magnifier: (1)The origin, courses,branches,distribution of the perforator of the first plantar metatarsal artery; (2)The anastomoses among the perforator of the first plantar metatarsal artery and other arteries on the medial aspect of the foot. Simulated operation was performed on one fresh specimen.

RESULTSThe perforator of the first plantar metatarsal artery passed through the space between the tendon, the abductor hallucis and the first metatarsal bone, and its entry point into the deep fascia was located (2. 3 ± 0.7 ) cm proximal to the first metatarsophalangeal joint. The perforator anastomosed with either the medial tarsal artery, the medial anterior malleolus artery or the branch of the medial plantar artery on the superior margin of the abductor hallucis, forming a longitudinal arterial chain,through which small branches were given off to the skin of the medial aspect of the foot. The perforator was( 1. 1 ± 0.2) mm in diameter and(3.2 ± 0.2) cm in length.

CONCLUSIONThe flap based on the perforator of the first plantar metatarsal artery can be harvested as an axial flap to repair the defects of soft tissue on the forefoot.

Anatomic Landmarks ; anatomy & histology ; Arteries ; anatomy & histology ; Cadaver ; Foot ; Foot Injuries ; surgery ; Humans ; Metatarsal Bones ; blood supply ; Metatarsophalangeal Joint ; anatomy & histology ; Muscle, Skeletal ; anatomy & histology ; Perforator Flap ; blood supply ; Reconstructive Surgical Procedures

OBJECTIVETo assess the safety and the accuracy of surgical navigation technology in the resection of severe ankylosis of the mandibular condyle with the middle cranial fossa.

METHODSThe CT scan data was transferred to a Windows-based computer workstation, and the patient' s individual anatomy was assessed in multiplanar views at the workstation. In the operation, the patient and the virtual image were matched by individual registration with the reference points which were set on the skull bone surface and the teeth. Then the real time navigation can be performed.

RESULTSThe acquisition of the data sets was uncomplicated, and image quality was sufficient to assess the operative result in three cases. The operations were performed successfully with the guidance of real-time navigation. The application of surgical navigation have enhanced the safety and the accuracy of the surgery for bony ankylosis of temporomandibular joint.

CONCLUSIONSThe application of surgical navigation can improve the accuracy and safety of surgical excision of the ankylosed skull base tissue.

Anatomic Landmarks ; anatomy & histology ; Ankylosis ; surgery ; Humans ; Skull ; diagnostic imaging ; surgery ; Surgery, Computer-Assisted ; methods ; Temporomandibular Joint ; surgery ; Temporomandibular Joint Disorders ; surgery ; Tomography, X-Ray Computed

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: To investigate the possibility and anatomy landmark of the frontal beak approach of endoscopic frontal sinusotomy to the frontal sinus lesions. METHOD: (1)Twenty cases of frozen cadaveric head underwent spiral computed tomography scans. Then data were transferred into the Mimics image workstation to reorganize CT images in the coronal, sagittal, and axial planes. The anatomic parameters related to surgical approach points were measured, such as the distance between vertical plate of the middle turbinate and lamina papyracea and the thickness of the frontal beak. (2) 3D visual model of the frontal cell and the drainage way of the frontal sinus was produced with the application of Sinuses Trachea I software. (3)The endoscopic frontal sinus surgery were performed on 20 cases of subjects (objects)to find out the anatomy landmarks of the frontal beak approach, measure the parameters such as the distance between middle turbinate and lamina papyracea, and evaluate the potential surgical complications during operation. RESULT: (1)The frontal beak is a white bony arcs located at the attachment point of middle turbinate front inserted to the skull base. Its position was relatively constant, before frontal sinus above. (2)The distance between the middle turbinate vertical plate and lamina papyracea was (7. 61 ± 1. 34) mm. The thickness of the frontal beak in surgical approach was (3. 27 ± 0. 91) mm. (3) 3D visual structure of the frontal sinus and its ventilation pathway: the shape of unilateral frontal sinus looked like the cone, which was transited by the drainage pathway of the frontal sinus. The front part of the frontal sinus ostium is surrounded by the frontal beak. The upper part the frontal beak connected to the floor of the frontal sinus. (4) Frontal beak can be used as an landmark of frontal beak approach in the endoscopic frontal sinus surgery. But the lateral view of frontal sinus still was limited in the operation. CONCLUSION The endoscopic frontal sinus surgery with the approach of the frontal beak is easy to operate and learn. In this area between the double "L", the operation is safe.
Anatomic Landmarks ; Endoscopy ; methods ; Frontal Sinus ; surgery ; Humans ; Skull Base ; Software ; Tomography, Spiral Computed ; Tomography, X-Ray Computed ; Turbinates ; anatomy & histology

OBJECTIVETo investigate the clinical effect of lateral superior genicular composite tissue flap for tissue defect.

METHODSThe axis line of flap is the lateral thigh vertical midline. The cutaneous branch is inserted 4 cm near the femoral lateral epicondylus. The anterior border is the elongation line along patellar lateral border. The posterior margin is the hinder margin of femoral biceps. The lower border is the horizontal line along the upper line of patella. The composite flaps were used in 18 cases with soft tissue defects in extremities, 11 cases with clacaneus tenden defects and 16 cases with bony nonunion. Results From Mar. 2002 to Sept. 2013, 45 cases were treated with the composite tissue flaps. The flaps size ranged from 6 cm x 3 cm to 17cm x 9 cm. All the flaps survived completely. Blood supply crisis happened in 2 cases, which was released by reanastomosis. The patients were followed up for 1 - 2. 5 years with satisfactory aesthetic and functional results. All the bone defect and nonunion were healed. Good healing was also achieved in donor sites. 8 months after operation, knee joint function is evaluated as good by hospital special surgery knee score (HSS).

CONCLUSIONLateral superior genicular compostie tissue flap can be used to reconstruct soft tissue defect, bone defect and tenden calcaneus defect in one stage.

Anatomic Landmarks ; anatomy & histology ; Follow-Up Studies ; Graft Survival ; Humans ; Knee ; anatomy & histology ; Muscle, Skeletal ; anatomy & histology ; Soft Tissue Injuries ; pathology ; surgery ; Surgical Flaps ; transplantation ; Thigh ; Time Factors ; Wound Healing

OBJECTIVE: To evaluate the value of spinal and paraspinal anatomic markers in both the diagnosis of lumbosacral transitional vertebrae (LSTVs) and identification of vertebral levels on lumbar MRI. MATERIALS AND METHODS: Lumbar MRI from 1049 adult patients were studied. By comparing with the whole-spine localizer, the diagnostic errors in numbering vertebral segments on lumbar MRI were evaluated. The morphology of S1-2 disc, L5 and S1 body, and lumbar spinous processes (SPs) were evaluated by using sagittal MRI. The positions of right renal artery (RRA), superior mesenteric artery, aortic bifurcation (AB) and conus medullaris (CM) were described. RESULTS: The diagnostic error for evaluation of vertebral segmentation on lumbar MRI alone was 14.1%. In lumbarization, all patients revealed a well-formed S1-2 disc with squared S1 body. A rhombus-shaped L5 body in sacralization and a rectangular-shaped S1 body in lumbarization were found. The L3 had the longest SP. The most common sites of spinal and paraspinal structures were: RRA at L1 body (53.6%) and L1-2 disc (34.1%), superior mesenteric artery at L1 body (55.1%) and T12-L1 disc (31.6%), and AB at L4 body (71.1%). CM had variable locations, changing from the T12-L1 disc to L2 body. They were located at higher sacralization and lower lumbarization. CONCLUSION: The spinal morphologic features and locations of the spinal and paraspinal structures on lumbar MRI are not completely reliable for the diagnosis of LSTVs and identification on the vertebral levels.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Anatomic Landmarks/*anatomy & histology ; Aorta, Abdominal/anatomy & histology ; Diagnostic Errors ; Female ; Humans ; Intervertebral Disc/anatomy & histology ; Lumbar Vertebrae/*anatomy & histology ; Lumbosacral Region ; Magnetic Resonance Imaging ; Male ; Mesenteric Artery, Superior/anatomy & histology ; Middle Aged ; Renal Artery/anatomy & histology ; Reproducibility of Results ; Sacrum/*anatomy & histology ; Spinal Cord/anatomy & histology ; Spine ; Young Adult

OBJECTIVE: To investigate the related parameters of temporal bone structure in the surgery of cochlear implantation through facial recess approach so as to offer a theoretical reference for the avoidance of facial nerve injury and the accurate localization. METHOD: In a surgical simulation experiment, twenty human temporal bones were studied. The correlation parameters were measured under surgical microscope. RESULT: Distance between suprameatal spine and short process of incus was (12.44 +/- 0.51) mm. Width from crotch of chorda tympani nerve to stylomastoid foramen was (2.67 +/- 0.51) mm. Distance between short process of incus and crotch of chorda tympani nerve was (15.22 +/- 0.83) mm. The location of maximal width of the facial recess into short process of incus, crotch of chorda tympani nerve were (6.28 +/- 0.41) mm, (9.81 +/- 0.71) mm, respectively. The maximal width of the facial recess was (2.73 +/- 0.20) mm. The value at level of stapes and round window were (2.48 +/- 0.20 mm) and (2.24 +/- 0.18) mm, respectively. Distance between pyramidalis eminence and anterior round window was (2.22 +/- 0.21) mm. Width from stapes to underneath round window was (2.16 +/- 0.14) mm. CONCLUSION These parameters provide a reference value to determine the position of cochlear inserting the electrode array into the scale tympani and opening facial recess firstly to avoid potential damage to facial nerve in surgery.
Anatomic Landmarks ; anatomy & histology ; Chorda Tympani Nerve ; anatomy & histology ; Cochlea ; anatomy & histology ; Cochlear Implantation ; methods ; Ear, Middle ; Facial Nerve Injuries ; prevention & control ; Humans ; Incus ; anatomy & histology ; Organ Sparing Treatments ; methods ; Round Window, Ear ; anatomy & histology ; Stapes ; anatomy & histology ; Temporal Bone ; anatomy & histology ; Tympanic Membrane ; anatomy & histology