• The Journal of the Korean dental association
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• v.57 no.4
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• pp.204-212
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• 2019

Introduction : Patients with temporomandibular disorder may have various ear-related symptoms. If an excessive load is applied to the ear area due to the skeletal shape of the mandibular condyle or malposition of the disc, an auditory problems may occur. Case report : The patient was referred to our clinic due to the suspicion of temporomandibular disorder from the local otorhinolaryngology clinic. A few days ago, his right ear could not be heard. MRI showed that the left TMJ disc was anterior displacement with reduction, the right TMJ disc was anteromedial displacement without reduction. Also Right mandibular condyle showed sclerotic bone change, subchondral cyst and was compressing the frontal wall of the ear on MRI view. Right TMJ arthroplasty was done under the diagnosis of right TMJ osteoarthritis and osteochondroma. Postoperative intermaxillary fixation was done with SAS screw and elastics for 2 weeks. One month after the operation, hearing and TMJ discomfort were recovered without any complications. Conclusions As seen in this case, hearing loss due to benign tumor-like lesions of the temporomandibular joint should be treated surgically to restore the TMJ function and hearing.

• Anatomy and Cell Biology
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• v.56 no.3
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• pp.342-349
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• 2023

This study was conducted to investigate the clinical and anatomical importance of the relevant region from the perspective of surgical approaches by determining the morphometric analysis of the craniocervical junction and foramen magnum (FM) region and determining their distances from important anatomical points. This research was carried out with 59 skulls found at the Anatomy Laboratories of Erciyes and Ankara Medipol University. Metric measurements of FM and condyle, FM shape, condyle-fossa relationship, and pharyngeal tubercle (PT) were made in mm-based dry bone samples of unknown age and sex. The distance between the anterior notches and the FM was 87.01±4.35, the distance between the anterior notches and the PT was 77.70±4.24, the distance between the PT-sphenooccipital junction was 13.23±2.42, and the FM index was 81.86±7.47. The anteroposterior and transverse lengths of FM were determined as 33.80±2.99 and 27.72±2.30, respectively. The morphometric and morphological data available regarding the craniocervical junction showed significant differences between populations. Comprehensive knowledge of this topic will provide a better approach to treat Arnold Chiari Malformation, FM meningiomas, and other posterior cranial fossa lesions. Therefore, we believe that FM and craniocervical junction morphology will be a guide not only for anatomists, but also for radiologists, neurosurgeons, ENT surgeons, and orthopedists.

• The korean journal of orthodontics
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• v.41 no.2
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• pp.87-97
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• 2011

Objective: Facial asymmetry is usually evaluated from the difference in length and angulation of the maxilla and mandible. However, asymmetric position or shape of the condyle can also affect the expression of asymmetry. The purpose of this study was to evaluate the correlation between condylar asymmetry and chin point deviation in facial asymmetry. Methods: Cone-beam CT images of fifty adult skeletal Class III patients were studied. Thirty patients who had more than 4 mm menton deviation were categorized in the asymmetric group. Twenty patients with less than 4 mm menton deviation were assigned to the symmetric group. Anteroposterior and transverse condyle positions were evaluated from the cranial base. The greatest mediolateral diameter (GMD) of the condyle in the axial plane and angulation to the coronal plane were measured. The height and volume of the condyles were evaluated. Results: The symmetric group had no statistical difference between both condyles in position, angulation, GMD, height and volume. In the asymmetric group, the non-deviated side condyle was larger in GMD, height and volume than the deviated side. There was no statistical difference in condyle position and angulation. The GMD, height difference and condylar volume ratio (non-deviated/deviated) were positively correlated with chin deviation. From the linear regression analysis, condylar volume ratio was a significant factor affecting chin deviation. Conclusions: These findings suggests that the non-deviated side condyle is larger than the deviated side. In addition, condylar asymmetry can affect the expression of facial asymmetry.

• Imaging Science in Dentistry
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• v.51 no.3
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• pp.271-278
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• 2021

Purpose: This study aimed to investigate the panoramic imaging features of cleidocranial dysplasia (CCD) with a relatively large sample. Materials and Methods: The panoramic radiographs of 40 CCD patients who visited Seoul National University Dental Hospital between 2004 and 2018 were analyzed. Imaging features were recorded based on the consensus of 2 radiologists according to the following criteria: the number of supernumerary teeth and impacted teeth; the shape of the ascending ramus, condyle, coronoid process, sigmoid notch, antegonial notch, and hard palate; the mandibular midline suture; and the gonial angle. Results: The mean number of supernumerary teeth and impacted teeth were 6.1 and 8.3, respectively, and the supernumerary teeth and impacted teeth were concentrated in the anterior and premolar regions. Ramus parallelism was dominant (32 patients, 80.0%) and 5 patients (12.5%) showed a mandibular midline suture. The majority of mandibular condyles showed a rounded shape (61.2%), and most coronoid processes were triangular (43.8%) or round (37.5%). The mean gonial angle measured on panoramic radiographs was 122.6°. Conclusion: Panoramic radiographs were valuable for identifying the features of CCD and confirming the diagnosis. The presence of numerous supernumerary teeth and impacted teeth, especially in the anterior and premolar regions, and the characteristic shapes of the ramus, condyle, and coronoid process on panoramic radiographs may help to diagnose CCD.

• Journal of the Korea Computer Graphics Society
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• v.23 no.5
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• pp.19-27
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• 2017

In this paper, we propose an automatic segmentation method of the mandible using shape-constrained information in cranio-maxillo-facial CBCT images. The proposed method consists of the following two steps. First, the mandible segmentation based on the global shape information is performed through the statistical shape model generated using the MDCT images. Second, improvement of mandible segmentation is performed considering the local shape information and intensity characteristics of the mandible. To evaluate the performance of the proposed method, the proposed method was evaluated qualitatively and quantitatively based on the results of manual segmentation by expert. Experimental results show that the Dice Similarity Coefficient of the proposed method was 95.64% and 90.97%, respectively, in the mandible body region including the narrow region of large curvature and the condyle region with large positional variance.

• Archives of Craniofacial Surgery
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• v.19 no.2
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• pp.152-156
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• 2018

Mandibular defects lead to severe deformation and functional deficiency. Vascularized osteocutaneous tissue has been widely used to reconstruct the mandible. However, it is technically challenging to shape this type of grafts in such a manner that they resemble the configuration of the mandible. A 48-year-old female patient who underwent anterolateral thigh (ALT) flap coverage after a tongue cancer excision was diagnosed with a tumor recurrence during the follow-up. A wide excision mandibulectomy and mandibular reconstruction with an ALT flap and a titanium implant were performed. The prefabricated titanium implant was fixed to the condyle. Then, an ALT flap was harvested from the ipsilateral thigh and anastomosed. After confirming that the circulation of the flap was intact, the implant was fixed to the parasymphysis. On the radiograph taken after the surgery, the prosthesis was well positioned and overall facial shape was acceptable. There was no postoperative complication during the follow-up period, 1 year and 2 months. The prefabricated implant allows the restoration of facial symmetry without harvesting autologous bone and it is a safe and effective surgical option for mandibular reconstruction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.5
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• pp.543-549
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• 2008

Distraction osteogenesis is a commonly used technique for mandibular lengthening, but changes in the temporomandibular joint(TMJ) have not been well documented. The TMJ is one of the most complex joint in the body and is composed of a fibrous surface layer, a proliferative zone, hypertrophic cartilage, and bone. The shape and role of the TMJ change and modify during a person's life-time. Possible complications that can arise after mandibular distraction include failure of the formation, failure of callus, infection, disturbance of TMJ and of occlusion. However, there are only a few reports on changes in the TMJ as a result of distraction osteogenesis. Hence, the goal of this study was to evaluate the change of the TMJ after experimental distraction of mandibular ramus in rabbit. We studied histological changes of mandibular condyle, articular disk and retrodiscal tissue, and also examined the collagen I gene expression and MMP-1 gene expression. The results were as follows. 1. In the histological staining, experimental condylar surface showed more thick fibrous articular layer and proliferative layer, compared with the control condyle and experimental articular disc showed thick and dense collagen fibers compared with the control disc. 2. In the collagen I and MMP-1 gene RT-PCR analysis, experimental discs showed increased collagen I expression compared with the control disc, while MMP-1 gene expression was decreased compared with the control disc. The retrodiscal tissue was almost equal expressions of the collagen I and MMP-1 genes compared with the control retrodiscal tissue. These findings suggest that histological and biomolecular changes occur in condyles and discs after unilateral mandibular distraction osteogenesis.

• Korean Journal of Head & Neck Oncology
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• v.21 no.2
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• pp.190-195
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• 2005

Background and Objectives: Fibula is the flap of choice for reconstruction of wide mandible defects after tumor ablation surgery. In mandible reconstruction, restoring the mandible frame to provide mandibular contour and dental arch while restoring masticatory function are important. Even though vascularized fibula can be osteotomized freely, proper design and flap insetting is not easy because of its three dimensional structure and difference in design according to the defect sites. We reviewed patients who underwent mandible reconstruction with fibular flaps according to the defect sites and suggest proper modification methods of fibular flap according to the various defects sites after tumor ablation surgery. Materials and Methods: Twelve consecutive mandible reconstruction with fibular free flaps were performed for defects after tumor ablation surgery. Patients were classified into 4 groups according to the type of mandibular defect(Group 1 : defect on central segment including symphysis, Group 2 : defect on lateral segment(with or without central segment) confined to body, Group 3 : defect on body and ascending ramus that does not include the condyle, Group 4 : defect including the condyle). Results: We suggest different modification methods of fibular free flap for each patient group. Group 1, 3 ; contour by using multiple closing wedge osteotomy. Group 2 ; single or double barrel reconstruction without wedge osteotomy. Group 4 ; contour using single or multiple wedge osteotomy and condylar reconstruction with costochondral graft. Conclusion: Fibular free flaps can be contoured to any desired shape after multiple osteotomies to restore various mandibular defects. It is a reliable and versatile method for reconstruction of mandibular defects after tumor ablation surgery.

• Imaging Science in Dentistry
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• v.37 no.1
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• pp.15-18
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• 2007

Purpose : Disc and condylar position were observed on MRIs of temporomandibular joint disorder patients and condylar position agreement between MRI and tranascranal radiography was evaluated. Materials and Methods MRI and transcranial radiographs of both TM joints from 67 patients with temporemandibular disorder were used. On MRI, the position and shape of disc and condylar position as anterior, middle, posterior was evaluated at medial, center, and lateral views. On transcranial radiographs, condylar position was evaluated using the shortest distance from condyle to fossa in anterior, superior, and posterior directions. Results. 1. On MRI, 96 joints (71.6%) of 134 had anterior disc dispalcement with reduction and 38 joints (28.4%) without reduction. 2. Fourteen (14.6%) of 96 reducible joints showed anterior condylar position, 19 (19.8%) showed central position, 63 joints (65.6%) showed posterior position. Two joints (5.3%) of 38 non-reducible joints showed anterior condylar position, while 9 (23.7%) showed central position, and 27 (71.1%)-posterior position. 3. In 85 joints (63.4%) of 134, the transcranial condylar position agreed with that of the central MRI view, 10 joints (7.5%) with that of medial, 16 joints (11.9%) with that of lateral, and 23 joints (17.2%) disagreed with that of MRI. Conclusion : On MRT, most oi the reducible and non-reducible joints showed posterior condylar position. Transcranial radiographs taken with machine designed for TMJ had better agreement of condylar position with that of MRI. Extremely narrow joint spaces or very posterior condylar positions observed on transcranial radiographs had a little more than fifty percent agreement with those of MRIs.

• Imaging Science in Dentistry
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• v.48 no.4
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• pp.283-287
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• 2018

Craniometaphyseal dysplasia (CMD) is a rare hereditary disorder characterized by hyperostosis of the craniofacial bones and flared metaphyses of the long bones. Although some reports have described the dentomaxillofacial characteristics of CMD, including increased density of the jaw, malocclusion, and delayed eruption of the permanent teeth, only a few studies have reported the distinct imaging features of CMD on panoramic radiography. This report presents 2 cases of confirmed CMD patients with an emphasis on panoramic imaging features. The patients' images revealed hyperostosis and sclerosis of the maxilla and mandibular alveolar bone, but there was no change in the mandibular basal bone. In both cases, the mandibular condyle heads exhibited a short clubbed shape with hyperplasia of the coronoid process. For patients without clear otorhinolaryngological symptoms, common radiologic features of CMD could be visualized by routinely-taken panoramic radiographs, and further medical examinations and treatment can be recommended.