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The Angle Orthodontist Sep 2007To examine the effects of mandibular lateral shift on the growth and morphology of the condyle and mandibular bone in growing rats.
OBJECTIVE
To examine the effects of mandibular lateral shift on the growth and morphology of the condyle and mandibular bone in growing rats.
MATERIALS AND METHODS
A maxillary resin plate was designed to displace 4-week-old rat mandibles 2 mm to the left during closure. The plate was cemented, and the rats were killed after 2, 4, 8, or 12 weeks. Gross dimensions of the condylar head were measured. Radiographic films of the mandibles were exposed, and selected measurements were made. The newly formed bone in the condyle was evaluated with periodic acid and Schiff's reagent (PAS) staining.
RESULTS
The length of the condylar head was greater on the ipsilateral side compared with the contralateral side. The experimental rats developed an asymmetric mandible, shorter in horizontal dimension but longer in the vertical dimension on the ipsilateral side. The mandibular growth direction was also affected, with the mandible on the ipsilateral side growing in a more anterior and superior direction. The amount of newly formed bone was greater in the superior subchondral region but lower in the posterior subchondral region on the ipsilateral side compared with the contralateral side.
CONCLUSIONS
Mechanical stimuli delivered by a functional shift produce a series of morphological and histological responses in the condyle and lead to condylar and mandibular asymmetry in rats.
Topics: Animals; Facial Asymmetry; Male; Mandible; Mandibular Condyle; Models, Animal; Osteogenesis; Radiography; Rats; Rats, Wistar
PubMed: 17685779
DOI: 10.2319/091806-377 -
The Chinese Journal of Dental Research Sep 2022To investigate the differences between temporomandibular articular fossa bone surface and the envelope surface of the mandibular condyle movement. (Comparative Study)
Comparative Study
OBJECTIVE
To investigate the differences between temporomandibular articular fossa bone surface and the envelope surface of the mandibular condyle movement.
METHODS
Thirty-four healthy adults underwent skull base and mandible scans using CBCT and performed mandibular border movement using the mandibular movement recording system. Landmarks of the fossa and tubercle were indicated and distance and angle parameters were measured on the 3D models reconstructed from the CBCT. The condyle movement envelope surfaces were formed according to models reconstructed from CBCT and the mandibular movement trajectory using computer simulation. The highest and lowest points of the envelope surface were indicated to create parameters. The data were analysed using a paired t test in SPSS (version 24.0, IBM, Armonk, NY, USA).
RESULTS
The mandibular fossa bone surface was statistically different to the envelope surface for the height of the first peak of the envelope surface (3.280 ± 1.319 mm) and depth of the mandibular fossa (6.338 ± 2.389 mm) (the ratio was 51.75%), the height of the second peak of the envelope surface (1.463 ± 0.745 mm) and the height of the tubercle (2.000 ± 0.968 mm) (the ratio was 73.15%), and the downwards angle of the envelope surface (25.933 ± 7.539 degrees) and the posterior slope angle of the articular tubercle (35.059 ± 5.224 degrees) (the ratio was 73.97%).
CONCLUSION
The downwards angle of the envelope surface was statistically significantly smaller than the posterior slope angle of the articular tubercle, suggesting that the condyle movement is flatter than the mandibular fossa bone surface.
Topics: Adult; Computer Simulation; Cone-Beam Computed Tomography; Humans; Mandible; Mandibular Condyle; Movement; Temporomandibular Joint
PubMed: 36102887
DOI: 10.3290/j.cjdr.b3317993 -
The Angle Orthodontist Nov 2009To clarify the relationship between occlusal force and mandibular condyle morphology using clinical data.
OBJECTIVE
To clarify the relationship between occlusal force and mandibular condyle morphology using clinical data.
MATERIALS AND METHODS
The subjects were 40 female patients with malocclusion. The mandibular condyle morphology was assessed by using limited cone-beam CT imaging. The maximum occlusal force was calculated by using pressure-sensitive films. Maxillofacial morphologies were analyzed by using data from lateral cephalograms.
RESULTS
Correlation analysis showed that the occlusal force was correlated with the lateral and posterior radii of the condyles, and with the mandibular plane angle to the Frankfort horizontal plane (FH). Moreover, condylar length was significantly correlated with the occlusal plane angle to the FH, the mandibular plane angle to the FH, the ramus inclination, and the posterior facial height (S-Go). Low-occlusal-force patients tended to have smaller mandibular condyles. This size-related difference was more remarkable on the lateral and posterior side.
CONCLUSIONS
Occlusal force influences not only maxillofacial morphology but also mandibular condyle morphology.
Topics: Bite Force; Cephalometry; Cone-Beam Computed Tomography; Female; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Malocclusion; Malocclusion, Angle Class I; Malocclusion, Angle Class II; Malocclusion, Angle Class III; Mandible; Mandibular Condyle; Vertical Dimension; Young Adult
PubMed: 19852595
DOI: 10.2319/120908-620R.1 -
BMC Oral Health Dec 2022The pathogenesis of traumatic temporomandibular joint (TMJ) bony ankylosis remains unknown. This study aimed to explore the pathogenesis of traumatic TMJ bony ankylosis...
BACKGROUND
The pathogenesis of traumatic temporomandibular joint (TMJ) bony ankylosis remains unknown. This study aimed to explore the pathogenesis of traumatic TMJ bony ankylosis in a rat model.
METHODS
Twenty-four 3-week-old male Sprague-Dawley rats were used in this study. Excision of the whole disc, the fibrocartilage damage of the condyle and glenoid fossa, and narrowed joint space were performed in the left TMJ of the operation group to induce TMJ bony ankylosis (experimental side). The right TMJ underwent a sham operation (sham side). The control group did not undergo any operations. At 1, 4, and 8 weeks postoperatively, rats of the operation group were sacrificed and TMJ complexes were evaluated by gross observation, Micro-CT, histological examinations, and immunofluorescence microscopy. Total RNA of TMJ complexes in the operation group were analyzed using RNA-seq.
RESULTS
Gross observations revealed TMJ bony ankylosis on the experimental side. Micro-CT analysis demonstrated that compared to the sham side, the experimental side showed a larger volume of growth, and a considerable calcified bone callus formation in the narrowed joint space and on the rougher articular surfaces. Histological examinations indicated that endochondral ossification was observed on the experimental side, but not on the sham side. RNA-seq analysis and immunofluorescence revealed that Matrix metallopeptidase 13 (MMP13) and Runt-related transcription factor 2 (RUNX2) genes of endochondral ossification were significantly more downregulated on the experimental side than on the sham side. The primary pathways related to endochondral ossification were Parathyroid hormone synthesis, secretion and action, Relaxin signaling pathway, and IL-17 signaling pathway.
CONCLUSIONS
The present study provided an innovative and reliable rat model of TMJ bony ankylosis by compound trauma and narrowed joint space. Furthermore, we demonstrated the downregulation of MMP13 and RUNX2 in the process of endochondral ossification in TMJ bony ankylosis.
Topics: Male; Rats; Animals; Mandibular Condyle; Rats, Sprague-Dawley; Ankylosis; Temporomandibular Joint
PubMed: 36494653
DOI: 10.1186/s12903-022-02560-0 -
American Journal of Orthodontics and... Aug 2019To evaluate whether the effects on the mandibular condylar cartilage (MCC) and subchondral bone are transient of botulinum neurotoxin (Botox) injection into the masseter...
OBJECTIVES
To evaluate whether the effects on the mandibular condylar cartilage (MCC) and subchondral bone are transient of botulinum neurotoxin (Botox) injection into the masseter muscle.
METHODS
Botox (0.3 U) was injected into the right masseter of 6-week-old female mice (C57BL/6; n = 16). In addition, 16 mice were used as control and received no injections. Experimental and matching control mice were killed 4 or 8 weeks after the single Botox injection. Mandibles and mandibular condyles were analyzed by means of microscopic computed tomography (microCT) and histology. Sagittal sections of condyles were stained for tartrate-resistant acid phosphatase (TRAP), toluidine blue, 5-ethynyl-2'-deoxyuridine (EdU), and terminal deoxynucleotide transferase-mediated dUTP nick-end labeling.
RESULTS
Bone volume fraction was significantly decreased on the subchondral bone of the Botox-injected side, compared with the control side and control mice, 4 and 8 weeks after injection. Furthermore, histologic analysis revealed decrease in mineralization, cartilage thickness, TRAP activity, and EdU-positive cells in the MCC of the Botox-injected side 4 and 8 weeks after injection.
CONCLUSIONS
The effects on the MCC and subchondral bone of Botox injection into the masseter muscle persisted for 8 weeks after injection and were not considered to be transient.
Topics: Animals; Apoptosis; Botulinum Toxins, Type A; Cell Proliferation; Female; Injections; Male; Mandible; Mandibular Condyle; Masseter Muscle; Mice; Mice, Inbred C57BL; Models, Animal; Temporomandibular Joint
PubMed: 31375229
DOI: 10.1016/j.ajodo.2018.08.023 -
Dento Maxillo Facial Radiology Jul 2020To critically synthesize the literature surrounding segmentation of the mandibular condyle using three-dimensional imaging modalities. Specifically, analyzing the...
OBJECTIVE
To critically synthesize the literature surrounding segmentation of the mandibular condyle using three-dimensional imaging modalities. Specifically, analyzing the reliability and accuracy of methods used for three-dimensional condyle segmentation.
METHODS
Three electronic databases were searched for studies reporting the reliability and accuracy of various methods used to segment mandibular condyles from three-dimensional imaging modalities. Two authors independently reviewed articles for eligibility and data extraction.
RESULTS
Nine studies fulfilled the inclusion criteria. Eight studies assessed the condylar segmentation from CBCT images and limited studies were available on non-CBCT three-dimensional imaging modalities. Threshold-based volume segmentation, manual segmentation, and semi-automatic segmentation techniques were presented. Threshold-based volume segmentation reported higher accuracy when completed by an experienced technician compared to clinicians. Adequate reliability and accuracy were observed in manual segmentation. Although adequate reliability was reported in semi-automatic segmentation, data on its accuracy were lacking.
CONCLUSION
A definitive conclusion with regards to which current technique is most reliable and accurate to efficiently segment the mandibular condyle cannot be made with the currently available evidence. This is especially true in terms of non-CBCT imaging modalities with very limited literature available.
Topics: Cone-Beam Computed Tomography; Imaging, Three-Dimensional; Mandibular Condyle; Reproducibility of Results
PubMed: 31778321
DOI: 10.1259/dmfr.20190150 -
Dento Maxillo Facial Radiology Jan 2010The objective of this study was to investigate the frequency and pattern of bifid mandibular condyles (BMCs). (Review)
Review
OBJECTIVE
The objective of this study was to investigate the frequency and pattern of bifid mandibular condyles (BMCs).
METHODS
A retrospective study was performed using panoramic radiographs from 10 200 patients undergoing dental treatment in the Department of Oral and Maxillofacial Radiology (Erzurum, Turkey) between 1996 and 2008.
RESULTS
Of the 10 200 patients, 32 (0.3%) had BMCs, of whom 17 were female (53.1%) and 15 were male (46.9%). The age range of the patients with BMCs was 5 to 71 years (mean age 30.0+/-0.40). Of these 32 patients, 24 (75.0%) had unilateral and 8 (25.0%) had bilateral BMCs, none of the patients had a history of trauma. No symptoms associated with bifid condyles were observed in any of the patients with BMCs.
CONCLUSIONS
It is possible that BMC is a more frequent condition than is commonly perceived. However, because of the minimal symptoms associated with this condition, the authors believe that it will remain an incidental finding upon routine radiographic examination, rather than a clinical observation. Nevertheless, in symptomatic cases or in cases where surgical treatment is planned, panoramic radiographs should be supplemented with CT.
Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Female; Humans; Incidental Findings; Jaw Abnormalities; Male; Mandibular Condyle; Middle Aged; Prevalence; Radiography, Panoramic; Retrospective Studies; Turkey; Young Adult
PubMed: 20089743
DOI: 10.1259/dmfr/38196548 -
Brazilian Oral Research Mar 2017This study aimed at verifying the correlation among angulation of the articular eminence (AE), shape of the condyle and its degenerative bone diseases (DBDs), according...
This study aimed at verifying the correlation among angulation of the articular eminence (AE), shape of the condyle and its degenerative bone diseases (DBDs), according to age and sex, through Cone Beam Computed Tomography (CBCT). Five hundred and twenty-eight temporomandibular joints (TMJ) were evaluated. The condyles were classified as: flat, convex, angled and rounded, and the AE angulation was measured. The DBDs evaluated were osteophytes, flattening, erosion, subcortical cysts and spinal sclerosis. There was no difference in the mean angulations in relation to age group (p>0.05). In age groups of 60-69 years (p=0.003) and 70 years or over (p=0.021), the angulation was higher in males. There was an association between DBD and sex (p=0.047), in that the prevalence was higher in females. Differences in AE angles were not observed in condyles with one or no DBDs (p>0.05). However, the presence of two or more DBDs led to a decrease in the angle (p<0.05). Angled condyles showed higher AE angulations than the flat and convex types (p<0.01). In conclusion, the AE inclination is influenced by DBD and condyle shape; an association of two or more bone diseases in the condyle, or its flat or convex anatomy, results in a decrease in the angulation.
Topics: Adult; Age Factors; Aged; Aged, 80 and over; Analysis of Variance; Cone-Beam Computed Tomography; Cross-Sectional Studies; Female; Humans; Male; Mandibular Condyle; Mandibular Diseases; Middle Aged; Reference Values; Retrospective Studies; Sex Factors; Statistics, Nonparametric; Temporomandibular Joint; Young Adult
PubMed: 28380089
DOI: 10.1590/1807-3107BOR-2017.vol31.0025 -
Dento Maxillo Facial Radiology May 2022The purpose of the present study was to validate and compare the accuracy and reliability of surface- and voxel-based registration on the mandibular rami for long-term...
Comparison of surface- and voxel-based registration on the mandibular ramus for long-term three-dimensional assessment of condylar remodelling following orthognathic surgery.
OBJECTIVES
The purpose of the present study was to validate and compare the accuracy and reliability of surface- and voxel-based registration on the mandibular rami for long-term three-dimensional (3D) evaluation of condylar remodelling following Orthognathic Surgery.
METHODS
The mandible was 3D reconstructed from a pair of superimposed pre- and postoperative (two years) cone-beam computerized tomography scans and divided into the condyle, and 21 ramal regions. The accuracy of surface- and voxel-based registration was measured by the absolute mean surface distance of each region after alignment of the pre- and postoperative rami. To evaluate the reliability, mean absolute differences and intraclass correlation coefficients (ICC) were calculated at a 95% confidence interval on volumetric and surface distance measurements of two observers. Paired t-tests were applied to statistically evaluate whether the accuracy and reliability of surface- and voxel-based registration were significantly different ( < 0.05).
RESULTS
A total of twenty subjects (sixteen female; four male; mean age 27.6 years) with class II malocclusion and maxillomandibular retrognathia, who underwent bimaxillary surgery, were included. Surface-based registration was more accurate and reliable than voxel-based registration on the mandibular ramus two years post-surgery ( < 0.05). The interobserver reliability of using surface-based registration was excellent, ICC range [0.82-1.00]. For voxel-based registration, the interobserver reliability ranged from poor to excellent [0.00-0.98]. The measurement error introduced by applying surface-based registration for assessment of condylar remodelling was considered clinical irrelevant (1.83% and 0.18 mm), while the measurement error introduced by voxel-based registration was considered clinical relevant (5.44% and 0.52 mm).
CONCLUSIONS
Surface-based registration was proven more accurate and reliable compared to voxel-based registration on the mandibular ramus for long-term 3D assessment of condylar remodelling following Orthognathic Surgery. However, importantly, the performance difference may be caused by an inappropriate reference structure, proposed in the literature, and applied in this study.
Topics: Adult; Cone-Beam Computed Tomography; Female; Humans; Imaging, Three-Dimensional; Male; Mandible; Mandibular Condyle; Orthognathic Surgery; Reproducibility of Results
PubMed: 35143288
DOI: 10.1259/dmfr.20210499 -
BMC Surgery Jun 2019Reconstruction of mandibular continuity and function after tumor resection is challenging, particularly in cases including the mandibular condyle. Various approaches for...
Vascularized scapula and latissimus dorsi flap for CAD/CAM assisted reconstruction of mandibular defects including the mandibular condyle: technical report and clinical results.
BACKGROUND
Reconstruction of mandibular continuity and function after tumor resection is challenging, particularly in cases including the mandibular condyle. Various approaches for reconstruction after disarticulation resection have been reported. However, the scapula flap has received little attention as a treatment option in these cases.
PATIENTS AND METHODS
Three cases of computer aided design and computer aided manufacturing (CAD/CAM) assisted reconstruction after disarticulation resection using a vascularized scapula and latissimus dorsi flap are reported. All cases required reconstruction of the mandibular ramus and condyle in combination with the reconstruction of large and complex soft tissue defects.
RESULTS
The surgical procedure was deemed successful in all cases. The scapula flap could be placed as preoperatively planned and patients regained their preoperative occlusion pattern and satisfying mouth opening-ranges. The large soft tissue defects could reliably be reconstructed using a latissimus dorsi flap.
CONCLUSIONS
The scapula and latissimus dorsi flap can be considered a suitable option for the reconstruction of mandibular disarticulation resection defects in combination with large soft tissue defects.
Topics: Aged; Computer-Aided Design; Female; Humans; Male; Mandibular Condyle; Middle Aged; Plastic Surgery Procedures; Scapula; Superficial Back Muscles; Surgical Flaps
PubMed: 31242878
DOI: 10.1186/s12893-019-0535-3