• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.4
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• pp.412-420
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• 1991

Seventeen rigid screw fixation and sixteen nonrigid wire fixation cases of mandibular sagittal slit ramus osteotomy were selected to compare postoperative dental and skeletal changes. A constructed horizontal plane was drawn seven degrees under sella-nasion plane and detailed cephalometirc assessment was applied to serial radiographic films taken before surgery($T_0$), immediately after surgery($T_1$), and at least six months after surgery($T_2$). Linear and angular positional changes were measured and analyzed statistically using paired t-test method and percent of positional changes(amount of post-op change/amount of intra-op change)${\times}100$. The results were as follows; 1. It was 29.4% in rigid fixation cases and 37.5% in nonrigid fixation cases comparing the postoperative positional change of more than 2mm at point B. So rigid fixation method was slightly more stable. 2. In nonrigid fixation cases, the positional change might be caused by incomplete bony union at the osteotomy site and soft tissue tension acting on this site. 3. In rigid fixation cases, the positional change might be caused by interaction between relapse tendency of protracted condyle-proximal segment and neighboring soft tissue tension.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.1
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• pp.16-20
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• 2014

Mandibular condylar hyperplasia is an uncommon condition of excessive unilateral growth of the condyle causing facial asymmetry and occlusal alterations. The etiology of condylar hyperplasia is unclear, but several factors are suspected, including previous trauma, hormonal disturbances, and abnormal functional loadings. Acute or chronic recurrent dislocation of temporomandibular joint (TMJ) is common, but long-standing dislocation is rare. We present two cases of the exophytic condylar hyperplasia that lasted for over 20 years with TMJ dislocation. In both cases, we performed a condyloplasty to restore normal occlusion and facial symmetry, with satisfactory results.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.1
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• pp.95-99
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• 1991

Several authors have proposed techniques and devices by which the correct position of the proximal segment can be maintained both during fixation and postoperatively. Schendel, Epker, Lake, Worms, Ive and Poulton have been discussed the problem of condylar distration in mandibular orthognathic surgery. This study described have showed the some advantages forward repositioning of the condyle head in vertical ramus osteotomy which used with the Mini-Hoffmann sets in external skeletal pin fixation extraorally in 19 cases.

• Imaging Science in Dentistry
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• v.51 no.3
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• pp.313-321
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• 2021

Ankylosis of the temporomandibular joint (TMJ) is a disabling disease resulting from fibrous or bony fusion of the mandibular condyle and the glenoid fossa. Early diagnosis and surgical treatment are essential to prevent facial deformity and other complications. Conventional radiography has limitations in demonstrating the true extent of ankylosis. It is important for surgeons to be aware of the size and degree of bony ankylosis in order to perform complete resection of the ankylotic mass. In addition, a detailed evaluation of the relationship with adjacent vital structures such as the internal maxillary artery, inferior alveolar nerve canal, external auditory canal, and skull base are crucial to avoid iatrogenic injury. Multidetector computed tomography (MDCT) is the current imaging modality of choice for preoperative assessments. Herein, the authors propose a structured CT reporting template for TMJ ankylosis to strengthen the value of the preoperative imaging report and to reduce the rates of intraoperative complications and recurrence.

• Journal of Oral Medicine and Pain
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• v.47 no.1
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• pp.67-71
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• 2022

Subchondral cysts are frequently encountered in patients with temporomandibular joint osteoarthritis (TMJ OA), particularly in advanced stage. Subchondral cysts within osteoarthritis are typically lying adjacent to the joint surface where initial load bearing occurs during activity and have been associated with greater pain and disease progression. Although the etiology of these cysts remains uncertain, recently studies report that the induction of the subchondral bone mechanical stress caused subchondral cysts. Repeated overloading leads to further deterioration of subchondral bone which render subchondral bone structure more fragile, increase the risk of osteoarthritis progress. The purpose of this study was to assess the effect of conservative treatment and longitudinal osseous changes of a large subchondral cyst in a mandibular condyle in a symptomatic TMJ OA patient.

• The korean journal of orthodontics
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• v.30 no.1 s.78
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• pp.43-52
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• 2000

Hemifacial microsomia ( HFM ) is the second most common craniofacial abnormalies. HFM represnted a spectrum of clinical findings such as hypoplasia of the mandibular ramus and condyle, confinement of maxilla growth, external and/or middle ear defects, involvement of some cranial suture, buccal soft tissue, facial nerve, and muscles in the affected side. HFM often showed progressive facial asymmetry and occlusal plane slanting to the affected side with growth. There were several reports about asymmetry of tooth maturation, hypodontia, delayed eruption, enamel hypoplasia in HFM. Since teeth develope in close association with size and morphology of the maxillary and the mandible, it is highly likely that dental changes will be present in HFM. So the Purpose of this study was to investigate the differences of the primary and the permanent teeth dimensions in the maxillary and the mandibular dentition between the affected and the non-affected side of HFM.. The sample of this study consisted of 34 unilateral HFM Patients (18 males and 16 females, average age : 5 year 11 months old). The authors examined the mesiodistal and the faciolingual dimensions of the primary and the permanent teeth and performed statistical study by using paired t-test. The results were as follows 1. The mesiodistal dimensions of the mandibular second primary molar and the mandibular first permanent molar in the affected side of HFM were significantly smaller than those of non-affected side. But there were no significant differences in the anterior teeth and the mandibular first primary molar. It means that a gradient of severity from anterior teeth to posterior teeth was found in the mandibular dentition. 2. Although there were no significant differences in the faciolingual dimensions of the primary and the permanent teeth in the maxillary and the mandibular dentition between the affected and non-affected side of HFM, there were general trend of compensatory increase in faciolingual dimension of the mandibular primary and the permanent teeth in the affected side Therefore these results showed that HFM might affect on the abnormality of tooth dimension, especially the most posterior teeth, in the affected side of the mandible.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.4
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• pp.305-315
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• 1998

The fibrous layer of mandibular condyle of the neonatal, 1-, 7-, 14-, 27-, 55-days and 1 year old rats were examined in the electron microscope with particular attention to the ultrastructure and diameter of collagen fibrils. In the 1-day rats, most of the cells of the fibrous layer were undifferentiated mesenchymal cells and fibroblasts with rough a little developed rough endoplasmic reticulum(RER) and golgi apparatus(GA). In 7-, 17 and 27-days old rats, most of the fibroblast showed well developed GA and RER with widely distended cisternae containing granular materials. In many of these cells contained intracytoplasmic filaments among the cytoplamic organelle. In 55-day and 1-year old rats, three types of cells were observed, ie, cells containing well developed cytoplasmic organelle presumed to be involved in the collagen fibril synthesis, cells showing well developed lysosomes, golgi apparatus, mitochondria and short cytoplasmic process presumed to be involved in the active resorption of the injured collagen fibrils or cellular debris, cells containing many intracytoplasmic filaments and a little organelle presumed to be cells of inactive state. The average diameters of collagen fibrils were similar in 1- and 7-day old rats as $38.48{\pm}3.81nm$, $38.06{\pm}3.86nm$. That was thickest in 14 days old rats as $50.21{\pm}3.93nm$ among experimental groups. They were gradually thinner in 27-, 55-day rats as $40.05{\pm}2.52nm$, $43.63{\pm}1.20nm$ and thinnest in 1-year old rats as $37.38{\pm}2.17nm$. The distribution pattern of diameters of collagen fibrils were unimordal with peak of 30-60nm in rats from 1-day to 17-day old. With aging from 27-day to 1 year old rats, collagen fibril diameters showed wide distribution pattern and percentage of thin collagen fibrils increased. These results may show the functional adaptation of fibrous layer of mandibular condyle to the increased mechanical forces with aging.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.50-62
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• 1989

This is clinicostatistical study of mandibular fractures. This study was based on a series of 677 patients with mandibular fracture during the period of 1982 to 1987. This results obtained were as follows : 1. In respect of incidence, there were high frequency in May and September, and in large city(63%). 2. The age frequency was the highest in the 20s-year old group (38.7%), and the ratio of male to female was 4.64 : 1. 3. The most common etiologic factor was blow(31.5%), but in children that was traffic accident followed by fall down. 4. The most common site of bone fractures was symphysis, followed by angle, condyle. In comparison of right and left sides, left side was more frequently involved(364 cases) than right side(257 cases). 5. The patients arrived in hospital immediately within 24 hours after accident were 62.9% of all, and 42.4% was arrived via private medical and dental clinic. 6. In respect of treatment, open reduction was 55.5% of all, closed reduction was 37.2%. In children, closed reduction was done in 50.6%.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.2
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• pp.80-87
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• 2020

Purpose: This study aims to measure the mandibular movement using JT-3D system and provide a range of mandibular movement that can serve as a good reference for diagnosing the temporomandibular disorder. Materials and Methods: This study was conducted in 60 young male and female adults. The maximum opening and closing movement was recorded using JT-3D system, and by regarding 5 times of repetitive movement as 1 cycle of movement, total 3 cycles of movement were recorded. During the maximum opening, vertical position of lower jaw, antero-posterior position, lateral deflection position, and maximum opening distance were recorded. To evaluate the reproducibility of JT-3D system, statistical analysis were conducted (α = 0.05). Results: During the maximum opening, the average value appeared at 31.56 mm vertically and 24.42 mm rearwardly, lateral deflection position 0.72 mm, and maximum opening distance 40.32 mm. There was no statistical significance in all measured values for three cycles of movement recorded with JT-3D system (P > 0.05). Conclusion: During the maximum opening, the average value appeared at 0.72 mm in lateral deflection position and the maximum opening distance at 40.32 mm, and the analysis on the maximum opening of lower jaw using JT-3D system showed sufficiently reproducible results.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.19 no.1
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• pp.123-136
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• 1989

The purpose of this study was to decide the diagnostic value of transmaxillary and transcranial projection in the evaluation of mandibular condyles. Five dry skulls with intact anatomic structure were selected for this study and the artificial osteophytes were attached to 9 different are as of the mandibular condyle. Ninety transcranial and forty-five transmaxillary radiographs were taken and then the radiographs were evaluated three times. The results were as follows; In transcranial radiographs, superocentral osteophyte was easily observed in closing state than in opening state (p<0.05). But there were no significant differences in other locations (p>0.05). The osteophytes on the medial and central portion easily observed at the transmaxillary projection than transcranial projection (p<0.05), but there was no significant difference on the lateral portion (p>0.05). The osteophytes on the superior (p<0.01) and posterior (p<0.01.) portion were easily observed at the transmaxillary projection than transcranial projection, but there was no significant difference on the anterior portion (p >0.05). The more laterally located osteophytes (p<0.01) at the transcranial projections were easily observed. The more posteriorly located osteophytes (p<0.05) at the transmaxillary projections were easily observed.