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Oral and Maxillofacial Surgery Mar 2022The close topographic relationship between vascular and osseous structures in the condylar and subcondylar region and marked variability in the arterial course has been...
Proximity of the middle meningeal artery and maxillary artery to the mandibular head and mandibular neck as revealed by three-dimensional time-of-flight magnetic resonance angiography.
PURPOSE
The close topographic relationship between vascular and osseous structures in the condylar and subcondylar region and marked variability in the arterial course has been revealed by both imaging and cadaveric studies. This study aimed to verify the previously published information in a large sample and to determine a safe surgical region.
METHODS
We analyzed the three-dimensional time-of-flight magnetic resonance angiography images of 300 individuals.
RESULTS
The mean distance between the middle meningeal artery and the apex of the condyle or the most medial point of the condyle was 18.8 mm (range: 11.2-25.9 mm) or 14.5 mm (range: 8.8-22.9 mm) respectively. The course of the maxillary artery relative to the lateral pterygoid muscle was medial in 45.7% of cases and lateral in 54.3%. An asymmetric course was evident in 66 patients (22%). The mean distance between the maxillary artery and condylar process at the deepest point of the mandibular notch was 6.2 mm in sides exhibiting a medial course (range: 3.7-9.8 mm) and 6.6 mm in sides exhibiting a lateral course (range: 3.9-10.4 mm). The distances were significantly influenced by age, gender, and the course of the maxillary artery.
CONCLUSION
Our study emphasizes the marked inter- and intra-individual variability of the maxillary and middle meningeal arterial courses. We confirmed the proximity of the arteries to the condylar process. Extensive surgical experience and thorough preparation for each individual case are essential to prevent iatrogenic vascular injury.
Topics: Humans; Magnetic Resonance Angiography; Mandible; Mandibular Condyle; Maxillary Artery; Meningeal Arteries
PubMed: 34024006
DOI: 10.1007/s10006-021-00960-0 -
Annual International Conference of the... Jul 2020Temporomandibular joints (TMJ) like a hinge connect the jawbone to the skull. TMJ disorders could cause pain in the jaw joint and the muscles controlling jaw movement....
Temporomandibular joints (TMJ) like a hinge connect the jawbone to the skull. TMJ disorders could cause pain in the jaw joint and the muscles controlling jaw movement. However, the disease cannot be diagnosed until it becomes symptomatic. It has been shown that bone resorption at the condyle articular surface is already evident at initial diagnosis of TMJ Osteoarthritis (OA). Therefore, analyzing the bone structure will facilitate the disease diagnosis. The important step towards this analysis is the condyle segmentation. This article deals with a method to automatically segment the temporomandibular joint condyle out of cone beam CT (CBCT) scans. In the proposed method we denoise images and apply 3D active contour and morphological operations to segment the condyle. The experimental results show that the proposed method yields the Dice score of 0.9461 with the standards deviation of 0.0888 when it is applied on CBCT images of 95 patients. This segmentation will allow large datasets to be analyzed more efficiently towards data sciences and machine learning approaches for disease classification.
Topics: Cone-Beam Computed Tomography; Humans; Mandibular Condyle; Skull; Temporomandibular Joint; Temporomandibular Joint Disorders
PubMed: 33018219
DOI: 10.1109/EMBC44109.2020.9175692 -
Experimental Biology and Medicine... Nov 2021After high fractures of the mandibular condyle, the insufficient blood supply to the condyle often leads to poor bone and cartilage repair ability and poor clinical...
After high fractures of the mandibular condyle, the insufficient blood supply to the condyle often leads to poor bone and cartilage repair ability and poor clinical outcome. Parathyroid hormone (PTH) can promote the bone formation and mineralization of mandibular fracture, but its effects on cartilage healing after the free reduction and internal fixation of high fractures of the mandibular condyle are unknown. In this study, a rabbit model of free reduction and internal fixation of high fractures of the mandibular condyle was established, and the effects and mechanisms of PTH on condylar cartilage healing were explored. Forty-eight specific-pathogen-free (SPF) grade rabbits were randomly divided into two groups. In the experimental group, PTH was injected subcutaneously at 20 µg/kg (PTH (1-34)) every other day, and in the control group, PTH was replaced with 1 ml saline. The healing cartilages were assessed at postoperative days 7, 14, 21, and 28. Observation of gross specimens, hematoxylin eosin staining and Safranin O/fast green staining found that every-other-day subcutaneous injection of PTH at 20 µg/kg promoted healing of condylar cartilage and subchondral osteogenesis in the fracture site. Immunohistochemistry and polymerase chain reaction showed that PTH significantly upregulated the chondrogenic genes Sox9 and Col2a1 in the cartilage fracture site within 7-21 postoperative days in the experimental group than those in the control group, while it downregulated the cartilage inflammation gene matrix metalloproteinase-13 and chondrocyte terminal differentiation gene ColX. In summary, exogenous PTH can stimulate the formation of cartilage matrix by triggering Sox9 expression at the early stage of cartilage healing, and it provides a potential therapeutic protocol for high fractures of the mandibular condyle.
Topics: Animals; Cartilage; Collagen Type II; Female; Fracture Fixation, Internal; Male; Mandibular Condyle; Mandibular Fractures; Matrix Metalloproteinase 13; Osteogenesis; Parathyroid Hormone; Rabbits; SOX9 Transcription Factor; Up-Regulation; Wound Healing
PubMed: 34233524
DOI: 10.1177/15353702211027114 -
Beijing Da Xue Xue Bao. Yi Xue Ban =... Feb 2024To establish and assess the precision of pre-surgical condyle position planning using mandibular movement trajectory data for orthognathic surgery.
OBJECTIVE
To establish and assess the precision of pre-surgical condyle position planning using mandibular movement trajectory data for orthognathic surgery.
METHODS
Skull data from large-field cone beam computed tomography (CBCT) and dental oral scan data were imported into IVSPlan 1.0.25 software for 3D reconstruction and fusion, creating 3D models of the maxilla and mandible. Trajectory data of mandibular movement were collected using a mandibular motion recorder, and the data were integrated with the jaw models within the software. Subsequently, three-dimensional trajectories of the condyle were obtained through matrix transformations, rendering them visually accessible. A senior oral and maxillofacial surgeon with experience in both diagnosis and treatment of temporomandibular joint disease and orthognathic surgery selected the appropriate condyle position using the condyle movement trajectory interface. During surgical design, the mobile mandibular proximal segment was positioned accordingly. Routine orthognathic surgical planning was completed by determining the location of the mandibular distal segment, which was based on occlusal relationships with maxilla and facial aesthetics. A virtual mandible model was created by integrating data from the proximal and distal segment bone. Subsequently, a solid model was generated through rapid prototyping. The titanium plate was pre-shaped on the mandibular model, and the screw hole positions were determined to design a condylar positioning guide device. In accordance with the surgical plan, orthognathic surgery was performed, involving mandibular bilateral sagittal split ramus osteotomy (SSRO). The distal segment of the mandible was correctly aligned intermaxillary, while the proximal bone segment was positioned using the condylar positioning guide device and the pre-shaped titanium plate. The accuracy of this procedure was assessed in a study involving 10 patients with skeletal class Ⅱ malocclusion. Preoperative condyle location planning and intraoperative positioning were executed using the aforementioned techniques. CBCT data were collected both before the surgery and 2 weeks after the procedure, and the root mean square (RMS) distance between the preope-rative design position and the actual postoperative condyle position was analyzed.
RESULTS
The RMS of the condyle surface distance measured was (1.59±0.36) mm (95%: 1.35-1.70 mm). This value was found to be significantly less than 2 mm threshold recommended by the expert consensus ( < 0.05).
CONCLUSION
The mandibular trajectory may play a guiding role in determining the position of the mandibular proximal segment including the condyle in the orthognathic surgery. Through the use of a condylar positioning guide device and pre-shaped titanium plates, the condyle positioning can be personalized and customized with clinically acceptable accuracy.
Topics: Humans; Mandibular Condyle; Orthognathic Surgery; Titanium; Mandible; Orthognathic Surgical Procedures; Osteotomy, Sagittal Split Ramus
PubMed: 38318897
DOI: 10.19723/j.issn.1671-167X.2024.01.010 -
Cartilage Dec 2021Bone morphogenetic protein 2 (BMP2) plays important roles in cartilage growth and development. Paradoxically, elevated levels of BMP2 leads to hypertrophic...
OBJECTIVE
Bone morphogenetic protein 2 (BMP2) plays important roles in cartilage growth and development. Paradoxically, elevated levels of BMP2 leads to hypertrophic differentiation and osteoarthritis of cartilage. We examined the loss of BMP2 in cells expressing aggrecan of the mandibular condyle and knee.
DESIGN
Three-week-old --positive mice and their Cre-negative littermates were treated with tamoxifen and raised until 3 or 6 months. We also investigated the direct effects of BMP2 on chondrocytes . Cells from the mandibular condyle of mice were treated with recombinant human BMP2 (rhBMP2) or rhNoggin (inhibitor of BMP2 signaling).
RESULTS
Conditional deletion of BMP2 caused breakage of the cartilage integrity in the mandibular condyle of mice from both age groups, accompanied by a decrease in cartilage thickness, matrix synthesis, mineralization, chondrocyte proliferation, and increased expression of degeneration markers, while the effects at articular cartilage were not significant. results revealed that rhBMP2 increased chondrocyte proliferation, mineralization, and differentiation, while noggin induced opposite effects.
CONCLUSIONS
In conclusion, BMP2 is essential for postnatal maintenance of the osteochondral tissues of the mandibular condyle.
Topics: Animals; Bone Morphogenetic Protein 2; Cartilage, Articular; Chondrocytes; Mandibular Condyle; Mice; Temporomandibular Joint
PubMed: 33307770
DOI: 10.1177/1947603520980158 -
Scientific Reports Nov 2022The aim of this study was to develop an auto-segmentation algorithm for mandibular condyle using the 3D U-Net and perform a stress test to determine the optimal dataset...
The aim of this study was to develop an auto-segmentation algorithm for mandibular condyle using the 3D U-Net and perform a stress test to determine the optimal dataset size for achieving clinically acceptable accuracy. 234 cone-beam computed tomography images of mandibular condyles were acquired from 117 subjects from two institutions, which were manually segmented to generate the ground truth. Semantic segmentation was performed using basic 3D U-Net and a cascaded 3D U-Net. A stress test was performed using different sets of condylar images as the training, validation, and test datasets. Relative accuracy was evaluated using dice similarity coefficients (DSCs) and Hausdorff distance (HD). In the five stages, the DSC ranged 0.886-0.922 and 0.912-0.932 for basic 3D U-Net and cascaded 3D U-Net, respectively; the HD ranged 2.557-3.099 and 2.452-2.600 for basic 3D U-Net and cascaded 3D U-Net, respectively. Stage V (largest data from two institutions) exhibited the highest DSC of 0.922 ± 0.021 and 0.932 ± 0.023 for basic 3D U-Net and cascaded 3D U-Net, respectively. Stage IV (200 samples from two institutions) had a lower performance than stage III (162 samples from one institution). Our results show that fully automated segmentation of mandibular condyles is possible using 3D U-Net algorithms, and the segmentation accuracy increases as training data increases.
Topics: Humans; Neural Networks, Computer; Algorithms; Mandibular Condyle; Cone-Beam Computed Tomography; Exercise Test
PubMed: 36446860
DOI: 10.1038/s41598-022-24164-y -
Folia Morphologica 2020The aim of this study was to compare the trabecular bone microstructure of the mandibular condyle in edentulous, unilateral edentulous (Kennedy Class II), and fully...
BACKGROUND
The aim of this study was to compare the trabecular bone microstructure of the mandibular condyle in edentulous, unilateral edentulous (Kennedy Class II), and fully dentate patients.
MATERIALS AND METHODS
The study used the cone-beam computed tomography (CBCT) images of 17 fully dentate (34 condyles), 16 edentulous (32 condyles), and 17 unilateral edentulous patients (34 condyles) aged 19 to 80 years. The trabecular bone microstructure of the mandibular condyle was evaluated on 8 consecutive cross-sectional images of these patients. In the microstructure analysis, structural model index (SMI), ellipsoid factor (EF), bone volume fraction (BV/TV), trabecular thickness (Tb.Th) and trabecular seperation (Tb.Sp) were measured.
RESULTS
There was no significant difference between the mean SMI, BV/TV, EF and Tb.Th microstructure values of each group (p = 0.243, p = 0.095, p = 0.962, p = 0.095, respectively). However, there was significant difference in terms of mean Tb.Sp between the groups (p = 0.021). The trabecular structure in all three groups was more rod-shaped. No correlation was found between age factor and microstructure values.
CONCLUSIONS
Considering the in vivo microstructure analysis of CBCT images, it can be said that teeth loss does not have a significant effect on the microstructure parameters excluding Tb.Sp of mandible condyles and does not affect mandibular condyle trabecular endurance.
Topics: Cancellous Bone; Cone-Beam Computed Tomography; Humans; Mandibular Condyle; Mouth, Edentulous; X-Ray Microtomography
PubMed: 31802471
DOI: 10.5603/FM.a2019.0133 -
Folia Morphologica 2021Few studies have investigated the volumetric relationship between the condyles and the mandible bilaterally.
BACKGROUND
Few studies have investigated the volumetric relationship between the condyles and the mandible bilaterally.
MATERIALS AND METHODS
Condylar and mandibular segmentations from a sample of cone-beam computed tomography for 37 individuals were selected. T-test, correlation and linear regression analyses were performed to assess the relationships between the volumes of the condyles and mandible.
RESULTS
The volume of the condyles and the mandible was significantly different between genders (p < 0.05). There was a significant but moderate correlation between the volumes of the condyle and the rest of the mandible on the same side (p < 0.01). A regression analysis model demonstrated that condylar volume is related to the volume of the mandible.
CONCLUSIONS
The relationship between the condylar volume and the rest of the mandible was found to be moderate. The relation between the condylar volume and mandibular volume is described by the regression equations for each side of the jaw. Sexual dimorphism exists in condylar and mandibular volumes.
Topics: Cone-Beam Computed Tomography; Female; Humans; Imaging, Three-Dimensional; Male; Mandible; Mandibular Condyle
PubMed: 32896875
DOI: 10.5603/FM.a2020.0104 -
Dento Maxillo Facial Radiology Mar 2022To investigate the size and morphology of the temporomandibular joint (TMJ) articular disc and condyle in young asymptomatic adults by using magnetic resonance imaging...
OBJECTIVE
To investigate the size and morphology of the temporomandibular joint (TMJ) articular disc and condyle in young asymptomatic adults by using magnetic resonance imaging (MRI) and to provide a reference for clinical diagnosis and scientific study of temporomandibular disorders (TMD).
METHODS
Overall, 93 undergraduate volunteers without TMD were enrolled from the freshmen pool at the Qingdao University. All participants underwent MRI of the oblique sagittal and oblique coronal TMJ planes. The articular disc and condyle were subsequently measured, and their morphology was evaluated. The obtained data were then grouped and analyzed statistically. Finally, intragroup correlation coefficient (ICC) was used to evaluate the interobserver measurement reliability.
RESULTS
We totally received 186 TMJ imaging samples. Based on our analysis, disc's anterior band in young asymptomatic adult females were thicker than males of the same age ( = 0.024). Moreover, the media-lateral dimensions of the condylar head of adult females were shorter than males of equal age (<0.001). The bilateral articular disc morphology was the same in 72.4% of subjects while the condylar morphology was the same in 63.4% of participants. Finally, using measurement reliability assessment, we demonstrated that our conclusions are reliable (ICC ≥0.7).
CONCLUSION
The thickness of the anterior band of the disc and the media-lateral dimensions of the condylar head were gender-related. Additionally, the morphology of the bilateral articular disc and condyle was different among the subset of young asymptomatic adults.
Topics: Adult; Bone and Bones; Female; Humans; Joint Dislocations; Magnetic Resonance Imaging; Male; Mandibular Condyle; Reproducibility of Results; Temporomandibular Joint
PubMed: 34644186
DOI: 10.1259/dmfr.20210272 -
BMJ Case Reports Sep 2020We present the case of a 60-year-old woman who presented to our unit with left-sided facial swelling, pain and trismus. Initially managed as a parotitis by a different...
We present the case of a 60-year-old woman who presented to our unit with left-sided facial swelling, pain and trismus. Initially managed as a parotitis by a different specialty, an ultrasound subsequently showed a collection deep to the parotid associated with an ectopic wisdom tooth within the mandibular posterior ramus/condyle and the patient was referred to our department. After treating the acute infection, the wisdom tooth was surgically removed. Our case highlights the importance of the clinician maintaining an open mind to differential diagnoses and details a technique for surgical removal of a tooth with difficult access.
Topics: Choristoma; Female; Humans; Mandibular Condyle; Mandibular Diseases; Middle Aged; Molar, Third; Tomography, X-Ray Computed; Tooth Extraction; Treatment Outcome; Trismus
PubMed: 32943442
DOI: 10.1136/bcr-2020-234871