• The korean journal of orthodontics
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• v.48 no.2
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• pp.73-80
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• 2018

Objective: This retrospective study compared the three-dimensional (3D) structure of mandibular condyles between adults with and without facial asymmetry, and whether it influences menton deviation. Methods: Sixty adult patients were classified into symmetry and asymmetry groups based on the menton deviation on postero-anterior radiographs. The right/left differences of 3D measurements were compared between the two groups, and measurements were compared separately on the right and left sides. The correlations between menton deviation and the right/left differences were analyzed. Results: The mediolateral dimension, neck length, condylar angles to the anteroposterior reference (PO) and midsagittal reference planes, and neck and head volumes showed significantly larger right/left differences in the asymmetry group compared to the symmetry group. Separate comparisons of the right and left sides between the two groups showed that the neck was significantly shorter and neck and head volumes were significantly smaller on the left side, which was deviated side in the asymmetry group. Pearson's correlation analysis showed significant positive correlations of menton deviation with right/left differences in neck length, condylar angle to the PO plane, and neck and head volumes in the asymmetry group. Conclusions: In individuals with facial asymmetry, menton deviation is associated with the right/left differences caused by a smaller condyle on the deviated side, particularly in neck length and neck and head volumes.

• Archives of Plastic Surgery
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• v.45 no.1
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• pp.23-28
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• 2018

Background Condylar process fractures account for one-third of all mandibular fractures, and the distal fragment is prone to dislocate to the medial side due to the pulling of the lateral pterygoid muscle. Retromandibular approaches are commonly used, but the intraoperative view becomes limited in medially dislocated fractures. This study summarized a series of cases of retromandibular reduction for medially dislocated condylar process fractures and described our supplementary procedure to realign the dislocated condylar process. Methods Nine patients with medially dislocated condylar process fractures underwent surgical correction from January 2012 to December 2016. In 6 of them, it was possible to realign the fractures with a conventional retromandibular approach, but for 3 cases of severe dislocation to the middle cranial fossa, a supplementary transoral procedure was carried out. The angle difference between the ramus and condyle, ramus height, and maximal mouth opening (MMO) were evaluated. Results All 9 cases were restored to the proper anatomical alignment without any major complications, and postoperative images revealed successful union. The angle difference was $8.94^{\circ}{\pm}4.11^{\circ}$ preoperatively, and $0.99{\pm}0.49^{\circ}$ at the 6-month follow-up. The pretreatment ramus height difference was $6.12{\pm}6.09mm$, and the postoperative difference was $0.18{\pm}0.10mm$. These changes after surgery were statistically significant. The MMO before surgery was $11.44{\pm}3.0mm$, and the postoperative MMO was $37.2{\pm}2.9mm$, reflecting a significant increase after reduction. Conclusions Retromandibular reduction is a useful method in medially dislocated condylar process fractures, and additional transoral assistance should be considered to realign condylar processes that severely dislocate to the middle cranial fossa.

• 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.

• The korean journal of orthodontics
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• v.46 no.6
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• pp.395-408
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• 2016

We report a case involving a young female patient with severe mandibular retrognathism accompanied by mandibular condylar deformity that was effectively treated with Le Fort I osteotomy and two genioplasty procedures. At 9 years and 9 months of age, she was diagnosed with Angle Class III malocclusion, a skeletal Class II jaw relationship, an anterior crossbite, congenital absence of some teeth, and a left-sided cleft lip and palate. Although the anterior crossbite and narrow maxillary arch were corrected by interceptive orthodontic treatment, severe mandibular hypogrowth resulted in unexpectedly severe mandibular retrognathism after growth completion. Moreover, bilateral condylar deformities were observed, and we suspected progressive condylar resorption (PCR). There was a high risk of further condylar resorption with mandibular advancement surgery; therefore, Le Fort I osteotomy with two genioplasty procedures was performed to achieve counterclockwise rotation of the mandible and avoid ingravescence of the condylar deformities. The total duration of active treatment was 42 months. The maxilla was impacted by 7.0 mm and 5.0 mm in the incisor and molar regions, respectively, while the pogonion was advanced by 18.0 mm. This significantly resolved both skeletal disharmony and malocclusion. Furthermore, the hyoid bone was advanced, the pharyngeal airway space was increased, and the morphology of the mandibular condyle was maintained. At the 30-month follow-up examination, the patient exhibited a satisfactory facial profile. The findings from our case suggest that severe mandibular retrognathism with condylar deformities can be effectively treated without surgical mandibular advancement, thus decreasing the risk of PCR.

• Imaging Science in Dentistry
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• v.31 no.4
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• pp.185-192
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• 2001

Purpose: To evaluate the condylar movement at maximal mouth opening on MRI in patients with internal derangement. Materials and Methods: MR images and transcranial views for 102 TMJ s in 51 patients were taken in closed and maximal opening positions, and the amount of condylar movement was analyzed quantitatively and qualitatively. Results: For MR images, the mean condylar movements were 9.4 mm horizontally, 4.6 mm vertically and 10.9 mm totally, while those for transcranial views were 12.5 mm, 4.6 mm, and 13.7 mm respectively. The condyle moved forward beyond the summit of the articular eminence in 41 TMJs (40.2%) for MR images and 56 TMJs (54.9%) for transcranial views. Conclusion: The horizontal and total condylar movements were smaller in MR images than in transcranial views.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.6
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• pp.412-420
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• 2013

The literature on alloplastic total temporomandibular joint (TMJ) replacement is encouraging, with acceptable improvement of treatment outcomes in terms of both pain level and jaw function. This is a case report on patients who suffered from degenerative joint disease and ankylosis after mandibular condyle fracture or prior TMJ surgery and were treated by TMJ replacement with condyle prosthesis. We obtained good results from the procedures, including total TMJ replacement.

• Journal of Korean Dental Science
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• v.1 no.1
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• pp.10-14
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• 2008

The fracture of facial bone usually accompanies alveolar bone fracture and dislocation or fracture of teeth. Thus, aside from the reduction of fracture, the reconstruction of occlusion through the rehabilitation of lost teeth should be considered. The dislocation of tooth after trauma accompanying alveolar bone fracture needs bone grafting in case of implant treatment. Although autogenous bone graft shows good prognosis, it has the disadvantage of requiring a secondary surgery. This is a case of a mandibular condyle head fracture accompanied by alveolar bone fracture. The condylar head fragment removed during open reduction was grafted to the alveolar bone fracture site, thereby foregoing the need for secondary surgery.

• Journal of the korean academy of Pediatric Dentistry
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• v.10 no.1
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• pp.57-65
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• 1983

The purpose of this study was to investigate the range of condylar movement of children with young permanent dentition. Materials included 33 roentgenograms of 4 serial projections of TMJ by modified transcranial projection with Accurad 100. Four serial projections were taken in the centric occlusion, rest position, 1 inch open, and maximum open position. The results obtained from this study were as follows. 1. The condyle was located anteriorly in articular fossa at centric occlusion. 2. The condyle was moved forwardly and downwardly during mandibular movement from centric occlusion to maximum open position. 3. The pattern of condylar movement was similar in both sexes, but there were no sex differences in distance of condylar movement.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.3
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• pp.279-283
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• 2000

Disc displacement, deformation, perforation or osteoarthritis may induce the joint space narrowing. This study was designed to get the normal joint space width which could be used as a standard comparing with damaged joints. Twenty asymptomatic volunteers' MR images were evaluated and coronal images of thirty joints having normal disc position in sagittal and coronal views, were selected. The joint spaces were measured at center, medial and lateral side on the coronal views. In normal joints, the mean joint space was $3.57{\pm}0.63mm$ at center, $2.77{\pm}0.51mm$ at medial and $2.41{\pm}0.41mm$ at lateral side of mandibular condyle. The mean of joint space of male was wider than that of female at center, but not significantly different at medial and lateral side of the condyle.

• The Journal of the Korean dental association
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• v.50 no.5
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• pp.256-261
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• 2012

Temporomandibular joint (TMJ) prosthesis have been hesitated to use because of bitter memories about Proplast-Teflon interpositional TMJ implants. Many clinicians, however, are trying to use total TMJ prosthesis with getting continuous long-term follow-up results. Alloplastic total TMJ replacement have been applied to much more patients who have failed previous TMJ prostheses or TMJ implants, fibrous/bony ankylosis, severe osteoarthritis, degenerative joint disease, idiopathic condylar resorption, condyle loss by trauma or tumor resection, and other bony destructive diseases. Nowadays three types of total TMJ prosthesis are widely used. In this article, indications, types of prosthesis, safety and stability would be demonstrated with a case report.