• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.36 no.3
• /
• pp.214-216
• /
• 2010

An osteochondroma is an osseous protuberance with cartilaginous growth potential, usually arising in skeletal bone and relatively uncommon in the craniofacial bone. Osteochondroma of the craniofacial region usually occurs at the condyle or the tip of the coronoid process, and rarely arises in the mandibular body, symphysis, ramus, and similar areas. Excision of the lesion including the periosteum is curative, and recurrence or malignant change (usually to a chondrosarcoma) after treatment is rare. We present an atypical case of osteochondroma in the left mandibular inferior border with review of literature.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.19 no.2
• /
• pp.130-134
• /
• 1997

The sagittal split ramus osteotomy(SSRO) of the mandible has used one of the most popula methods for the correction of various dentofacial deformities, especially mandibular prognathism. In SSRO, there are produced bony gap following mandible setback because of mandibular flaring. For this reason, the condylar axis may be changed due to bony approximation both segment in three dimension more mesio-laterally. According to change of condylar position, the condition of TMJ structure are changed and change of TMJ symptoms are suggested theoretically, and the correction of malocclusion by SSRO may improve the TMJ symptoms by improvement of feeding difficulties. The pupose of this study was to determine relationship between expected alterations in condylar position and suggested TMJ symptoms produced by change of condylar position. TMJ symptoms of 15patients who had operated SSRO are checked at about postoperative 6 month ranging $5{\sim}11$ month. Anterior-posterior position of condyle which was comparison preoperative with postoperative position, was classified 5 groups. The author tried to identify relationship between positional change of condyle and TMJ discomfort.

• Imaging Science in Dentistry
• /
• v.36 no.1
• /
• pp.41-48
• /
• 2006

Purpose : To evaluate the reliability and clinical usefulness of ultrasonography in the temporomandibular joint (TMJ). Materials and Methods : Parasagittal and paracoronal 1.5 T MR images and 7.5 MHz ultrasonographs of 40 TMJs in 20 asymptomatic volunteers were obtained. Disc position using MR imaging was evaluated and the distance between the lateral surface of mandibular condyle and the articular capsule using MR image and ultrasonograph of 27 TMJs with normal disc position was measured and compared. Intraobserver and interobserver measurements reliability was evaluated by using interclass correlation coefficients (ICC) and measurement error. Also, the distance measured on ultrasonographs was compared, according to mouth position and disc postion. Results : The normal disc position was found in 27 of 40 asymptomatic joints. At the intraobserver reliability of measurement, ICC at the closed and open mouth position were 0.89 and 0.91. The measurement error was 0.4% and 0.5%. At the interobserver reliability, ICC at the closed and open mouth position were 0.92 and 0.81. The measurement error was 0.4% and 0.7%. At the TMJ with normal disc position, the distances between the lateral surface of mandibular condyle and the articular capsule measured on MR images and ultrasonographs were $2.0{\pm}0.7mm,\;1.8{\pm}0.5mm$, respectively (p<0.05). On the ultrasonographs, the distances at open mouth position were $1.2{\pm}0.5mm$ (p<0.05). At the TMJ with medially displaced disc, the distances at the closed and open mouth position were $1.3{\pm}0.3\;mm\;and\;0.9{\pm}0.2\;mm$ (p<0.05). Conclusion : The results suggest ultrasonography of TMJ is a reliable imaging technique for assessment of normal disc position.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.32 no.1
• /
• pp.70-79
• /
• 2016

Patients who lost posterior teeth due to periodontitis or dental caries have collapsed vertical dimension, unstable occlusion and change of the mandibular position. In particular, patients in orthognathic surgery, clinician should re-establish the pre-operative stable position of mandibular condyle in articular fossa and favorable vertical dimension for high post-operative stability of mandible. Therefore, interdisciplinary approach and co-operation, including prosthetics, orthodontics, oral and maxillofacial surgeon, from diagnosis and treatment plan is important to get a good outcome. This case report was patients who had collapsed occlusal plane due to severe dental caries on maxillary molars with skeletal Class III malocclusion. Before orthognathic surgery, resetting of maxillary occlusal plane with temporary removable denture was performed. Then successful multidisciplinary approach was done and lead to acceptable clinical outcome.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.43 no.5
• /
• pp.331-335
• /
• 2017

Clinical limitations following closed reduction of an intracapsular condylar fracture include a decrease in maximum mouth opening, reduced range of mandibular movements such as protrusion/lateral excursion, and reduced occlusal stability. Anteromedial and inferior displacement of the medial condyle fragment by traction of the lateral pterygoid muscle can induce bone overgrowth due to distraction osteogenesis between the medial and lateral condylar fragments, causing structural changes in the condyle. In addition, when conventional maxillomandibular fixation (MMF) is performed, persistent interdental contact sustains masticatory muscle hyperactivity, leading to a decreased vertical dimension and premature contact of the posterior teeth. To resolve the functional problems of conventional closed reduction, we designed a novel method for closed reduction through protrusive MMF for two weeks. Two patients diagnosed with intracapsular condylar fracture had favorable occlusion after protrusive MMF without premature contact of the posterior teeth. This particular method has two main advantages. First, in the protrusive position, the lateral condylar fragment is moved in the anterior-inferior direction closer to the medial fragment, minimizing bone formation between the two fragments and preventing structural changes. Second, in the protrusive position, posterior disclusion occurs, preventing masticatory muscle hyperactivity and the subsequent gradual decrease in ramus height.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.11 no.1
• /
• pp.287-296
• /
• 1989

Fractures of the mandibular condyle are among the most frequently occuring facial bone fractures. Anatomical structures around the joint inhibit the ideal reposition of the fragments, so variable treatment modalities have been tried selectivly. There can be functional disturbances postoperatively, and normalization of joint function must be considered primarily in treatment planning. Secondly, the possible joint ankylosis and facial deformity following developmental disturbance of facial skeleton must be considered. The authors reviewed 73 patients treated in Dept. of Oral and Maxillofacial Surgery. Inje College of medicine Pusan Paik Hospital from 1981 to 1987. Also literatures were reviewed, and we obtained some reference points concerning the selection of the treatment modality and prevention of the possible complication.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.21 no.1
• /
• pp.73-81
• /
• 1991

The purpose of this study was to analyze the position of mandibular condyle on the submentovertex radiograph, thereafter to evaluate the usefulness of submentovertex radiograph in diagnosis of temporomandibular joint dysfunction, and to check the best method of tomographic techniques. Submentovertex radiographs which were taken in 75 temporomandibular joint dysfunction patients and 75 normal persons were used as the sample for this study. The obtained results were as follows: The submentovertex radiograph was a improper method in diagnosis of temporomandibular joint dysfunction and discrimination of affected side. The selective tomography was a better method than any other tomographic techniques in diagnosis of temporomandibular joint dysfunction.

• Journal of Technologic Dentistry
• /
• v.28 no.1
• /
• pp.53-59
• /
• 2006

The movement range on the semi adjustable articulator and the movement range in an oral were measured. And then I studied to analyze the gap. I got wax records by the movement on the semi adjustable articulator, the movement in an oral. I measured the distance of the cusp tips that are close to the mesial direction and the distal direction, the buccal direction and the lingual direction then I compared gaps. As I saw results on data, I knew that the semi adjustable articulator represented the range of mandibular movement restrictively. I could find the decisive contradiction that the sliding movement finished on the semi adjustable articulator although it did not finish in an oral. When the sliding movement does not reappear exactly, it brings a fatal failure to the dental prosthesis. In addition it is impossible that the semi adjustable articulator restores the movement in an oral because the lateral condyle inclination and the horizontal condyle inclination are appeared to be straight. Therefore dental prosthesisses were made by the semi adjustable articulator, they will interfere with a mastication. I have obtained the following results; 1. The distance of sliding movement on the semi adjustable articulator showed shorter than the distance of sliding movement in oral. This means the increase of cusp inclination of the dental prosthesis that was made on the semi adjustable articulator. Therefore, when the lateral movement occurs in oral, there is a possibility to become the premature as the increase of cusp inclination. 2. The difference in the range of movement is considered as the gap that is made because the movement only can be occurred as straight in the semi adjustable articulator. 3. When the dental technician understand mandibular movement and articulator deficiencies, they can attain proficiency in use of the articulator and reduce the gap.

• Imaging Science in Dentistry
• /
• v.38 no.2
• /
• pp.81-87
• /
• 2008

Purpose: To investigate the relationship between 3D bone architectural parameters and direction-related elastic moduli of cancellous bone of mandibular condyle. Materials and Methods: Two micro-pigs (Micro-$pig^R$, PWG Genetics Korea) were used. Each pig was about 12 months old and weighing around 44 kg. 31 cylindrical bone specimen were obtained from cancellous bone of condyles for 3D analysis and measured by micro-computed tomography. Six parameters were trabecular thickness (Tb. Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI), degree of anisotropy (DA) and 3-dimensional fractal dimension (3DFD). Elastic moduli of three orthogonal directions (superior-inferior (SI), medial-lateral (ML), andterior-posterior (AP) direction) were calculated through finite element analysis. Results: Elastic modulus of superior-inferior direction was higher than those of other directions. Elastic moduli of 3 orthogonal directions showed different correlation with 3D architectural parameters. Elastic moduli of SI and ML directions showed significant strong to moderate correlation with BV/TV, SMI and 3DFD. Conclusion: Elastic modulus of cancellous bone of pig mandibular condyle was highest in the SI direction and it was supposed that the change into plate-like structure of trabeculae was mainly affected by increase of trabeculae of SI and ML directions.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.23 no.2
• /
• pp.559-574
• /
• 1996

The purpose of this study was to determine whether there was any correlation between temporomandibular joint dysfunction and structure of the mandibular condyle. Weanling rats had their masseter muscles resected and immunohistochemical findings were observed with a light microscope. The results obtained were as follows : 1. The condylar cartilage region was divided into articular, proliferating, cartilage cell and hypertrophic cell layers according to cell morphology. 2. In light microscopic views, the proliferating and cartilage cell layers of the experimental group decreased gradually and at the 8th week significantly. 3. In immunohistochemical staining for type I and II collagen, a reaction was detected in the lower part of proliferating cell and cartilage cell layers. In the cartilage cell layers, a stronger cellular reaction was present. Immunohistochemical staining for type II collagen reacted more strongly than that of type I collagen. 4. In immunohistochemical staining for proteoglycan, the staining of the experimental group resembled the control group and gradually showed a weak reaction. The proliferating and cartilage cell layers reacted more strongly than the hypertrophic cell layer. 5. In immunohistochemical staining for proliferating cell nuclear antigen(PCNA), the strong reaction was detected in the nucleus of the proliferating cell layer both in control and experimental groups. But the thickness of the proliferating layer decreased in experimental group, consequently the reaction of the experimental group was reduced more than that of the control group.