• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.2
• /
• pp.329-334
• /
• 2006

Rail clamps are mechanical components installed to fix the container crane to its bottoms from wind blast or slip. Rail clamps should be designed to survive the harsh wind loading condition. In this study, the jaw structure that is one part of wedge-typed rail clamp is optimized, considering strength under the severe wind loading condition. According to the classification of structural optimization, the structural optimization of a jaw belongs to shape optimization. In the conventional structural optimization methods, they have difficulties in defining complex shape design variables and preventing mesh distortions. To overcome the difficulties, the metamodel using kriging interpolation method is introduced, replacing true response by approximate one. This research presents the shape optimization of a jaw using iterative kriging interpolation models and simulated annealing algorithm. The new kriging models are iteratively constructed by refining the former kriging models. This process is continued until the convergence criteria are satisfied. The optimum results obtained by the suggested method are compared with those obtained by the DOE (design of experiments) and VT (variation technology) methods built in ANSYS WORKBENCH.

• Imaging Science in Dentistry
• /
• v.49 no.3
• /
• pp.235-240
• /
• 2019

Osteosarcoma is the most common primary bone tumor after plasma cell neoplasms. Osteosarcoma has diverse histological features and is characterized by the presence of malignant spindle cells and pluripotent neoplastic mesenchymal cells that produce immature bone, cartilage, and fibrous tissue. Osteosarcoma most frequently develops in the extremities of long bones, but can occur in the jaw in rare cases. The clinical and biological behavior of osteosarcoma of the jaw slightly differs from that of long-bone osteosarcoma. The incidence of jaw osteosarcoma is greater in the third to fourth decades of life, whereas long-bone osteosarcoma mostly occurs in the second decade of life. Osteosarcoma of the jaw has a lower tendency to metastasize and a better prognosis than long-bone osteosarcoma. Radiographically, osteosarcoma can present as a poorly-defined lytic, sclerotic, or mixed-density lesion with periosteal bone reaction response. Multi-detector computed tomography is useful for identifying the extent of bone destruction, as well as soft tissue involvement of the lesion. The current case report presents a fibroblastic osteosarcoma involving the left hemimandible with very unusual radiographic features.

• Journal of Oral Medicine and Pain
• /
• v.46 no.4
• /
• pp.143-149
• /
• 2021

Purpose: Oromandibular dystonia is a neurological disorder that affects the jaw and lower face muscles, often resulting in abnormal repetitive movement of the jaw and perioral structures. The purpose of this study was to assess the effectiveness of surface electromyography (EMG) in evaluating the treatment outcome of oromandibular dystonia. Methods: Based on a retrospective review of medical records, we analyzed the data of four patients who received medication or botulinum toxin injection, as well as surface EMG of the jaw muscles before and after treatment. We assessed the patients' clinical characteristics and the results of surface EMG before and after treatment. Results: The case series included one female and three males, and the age range was 65-78 years. Based on the clinical features, two subjects were classified as jaw deviation and the remaining two were as jaw closing. Dystonic patterns revealed by surface EMG varied, including phasic, tonic, and mixed contraction patterns. EMG amplitude after treatment was lower than pre-treatment value in all four subjects, suggesting improved clinical signs and symptoms. One subject who received clonazepam and another who received botulinum toxin injection showed a remarkable reduction in EMG amplitude within a normal range. Conclusions: Surface EMG can be used to effective evaluate treatment outcomes in patients with oromandibular dystonia. It could be considered as an adjunctive diagnostic tool in managing patients with dystonia.

• Imaging Science in Dentistry
• /
• v.52 no.3
• /
• pp.309-317
• /
• 2022

Purpose: The aim of this study was to introduce a category of jaw lesions comprising cysts and tumors associated with scalloped borders. Materials and Methods: General search engines and specialized databases including Google Scholar, PubMed, PubMed Central, and Scopus, as well as an authoritative textbook, were used to find relevant studies by using keywords such as "jaw lesion," "jaw disease," "scalloping," "scalloped border," "scalloped margin," "irregular border," and "irregular margin." Out of 289 articles, 252 records were removed because they were duplicates, did not have a relevant title, or did not mention the frequency of findings described using the term "scalloped border." Finally, 37 closely related articles were chosen. Results: According to the relevant literature, scalloped borders are found most frequently in ameloblastoma, followed by simple bone cyst, central giant cell granuloma, odontogenic keratocyst, and glandular odontogenic cyst. Conclusion: The lesions most frequently reported to have scalloped borders are ameloblastoma, central giant cell granuloma, odontogenic keratocyst, simple bone cyst, and glandular odontogenic cyst.

• Journal of Oral Medicine and Pain
• /
• v.38 no.3
• /
• pp.275-289
• /
• 2013

This study was conducted to investigate and analyze the dental patients' awareness and understanding about TMDs. Among the total number of 243 patients who had visited the department of dentistry of Busan Paik Hospital, Inje University or Hanvit dental hospital in Ulsan metropolitan city and participated in the survey, 195 patients who filled in all parts of the questionnaire were selected as the subjects. The results were as follows. 1. The subjects who were aware of the term, "TMDs" were 17.4%. The group with total education period of 12 years and over was significantly more aware of "TMD"(82.4%, p<0.01) than the other group. The subjects who were aware of the term, "jaw joint disease" were 81.0%. 30 to 49 age group(45.6%, p<0.05) and the group with total education period of 12 years and over(60.1%, p<0.01) were significantly more aware of "jaw joint disease" than other groups. 2. More than half of the subjects chose "overuse of the jaws" as the concept of jaw joint disease(50.6%). 3. TV, radio(41.4%) was the most frequent source of awareness about jaw joint disease followed by family and friends(20.2%), hospitals and health professionals(18.2%), internet(15.7%) and newspapers, magazines(4.5%). Among the respondents who were aware of jaw joint disease through TV, radio, 30 to 49 age group showed significantly higher percentage(52.4%, p<0.05) than other age groups. Among the respondents who were aware of jaw joint disease through internet, 18 to 29 age group showed significantly higher percentage(61.3%, p<0.01) than other age groups. Among the respondents who were aware of jaw joint disease from hospitals and health professionals, the group with total education period of 12 years and over showed significantly higher percentage(75.0%, p<0.05) than the other group. 4. Noise during mouth opening and closing(26.9%), mouth opening difficulty(25.1%) and jaw pain(13.7%) were the most frequently responded sign and symptoms of jaw joint disease. For the causes of jaw joint disease, enjoying hard food chewing(19.5%), occlusal discrepancy(19.0%) and chewing with one side only(18.5%) were responded in sequence. TMJ surgery(28%) was the most frequently responded treatment method for jaw joint disease, followed by occlusal appliance therapy(23.9%) and physical therapy(14.6%). For preventive method of jaw joint disease, avoid eating hard food(21.1%), avoid opening mouth wide(17.0%) and simultaneous using of molar of both side when chewing food(15.4%) were chosen frequently.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.18 no.1
• /
• pp.5-12
• /
• 1988

Several cases of jaw cyst-basal cell nevus-bifid rib syndrome are presented. This syndrome consists principally of multiple jaw cysts, basal cell nevi, and bifid ribs but no one component is present in all patients. The purpose of this paper is to review the multiple characteristics of this syndrome and present three cases in a family and additional 4 cases. The many malformations associated with the syndrome have variable expressivity. In the cases, multiple jaw cysts, palmar and plantar pittings, bridging of sella, temporoparietal bossing, hypertelorism, cleft palate, and dystopia canthorum have been observed.

• Journal of Oral Medicine and Pain
• /
• v.23 no.4
• /
• pp.447-455
• /
• 1998

A 42-year old male patient was referred to the Department of Oral Medicine, Kyungpook National University Hospital due to the chief complaint of limite mouth opening. Three years ago, the patient was diagnosed as an infarction of both cerefellar hemispheres, acute obstructive hydrocephalus and acute epidural hematoma of frontal lobe at the department of neurosurgery.Both of the infarcted cerevellar hemispheres and the epidural hematoma of frontal lobe were removed with suboccipital and frontal craniectomu. After the brain surgery jaw opening range was decreased progressively and ultimately mouth opening became almost impossible. Spasmodic and rhythmic contractions of the masseter muscles occurred intermittently during daytime as well as sleeping. Food intake was available only through Levin -tube. Actibe jaw opening exercise was prescribed with the aids of tongue blades. A moist hot pack and indomethacin phonophesis were also applied 20 minutes three times a day to decrease discomfort muscle activities. After a month of treatments, the opening range was increased to 5mm at the premolar area and oral food intake was possibel. The L-tube was removed and the patient was discharged.

• Imaging Science in Dentistry
• /
• v.33 no.3
• /
• pp.195-198
• /
• 2003

We present two cases of multiple jaw cysts not associated with basal cell nevus syndrome. Case 1: a nine year-old boy visited CNU Hospital for orthodontic treatment and his radiographs showed cystic lesions surrounding the crowns of teeth #13 and #17 respectively, which were diagnosed as dentigerous cysts. Subsequently, two more cysts were found on his follow-up radiographs in 12 and 15 months. The two cysts were determined to be odontogenic keratocysts. The boy had no skeletal abnormalities and no skin lesions associated with basal cell nevus syndrome. Case 2: a fifty-eight year old man had three impacted third molars with pericoronal radiolucencies, which were diagnosed as dentigerous cysts. He had no additional abnormalities associated with basal cell nevus syndrome. Multiple jaw cysts can occur at any age, and periodic radiographic surveillance may be needed for any cases of impacted tooth.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.36 no.6
• /
• pp.508-514
• /
• 2010

Bisphosphonates are used effectively for many medical conditions, such as multiple myeloma, Paget's disease, osteoporosis, etc. However, recently, osteonecrosis of the jaw was observed in patients receiving long-term bisphosphonate therapy, including oral administration. This osteonecrosis is refractory, and complete recovery is not guaranteed despite a standard treatment protocol being established by many associations related to oral and maxillofacial surgery. The treatment outcome of oral bisphosphonate-related osteonecrosis of jaw (BRONJ) is reported with a review of the relevant literature.

• Phonetics and Speech Sciences
• /
• v.3 no.2
• /
• pp.29-35
• /
• 2011

This paper examines several articulatory properties of /k/, known as a trigger of place assimilation as well as the object of post-obstruent tensing (/tk/), in comparison to non-assimilating controls (/kk/ and /kt/). Using EMMA, tongue body articulation in the place assimilation context robustly shows greater spatio-temporal articulation and lower jaw position. Results showed several characteristics. Firstly, constriction duration of the tongue body gesture in C2 of the assimilation context (/tk/) was longer than non-assimilating controls (/kk/ and /kt/). Secondly, constriction maxima also demonstrated greater constriction in the /tk/ sequences than in the control /kk/, but similar values with the control /kt/. In particular, results showed a significant relationship between the two variables - the longer the constriction duration, the greater the constriction degree. Lastly, jaw height was lower for the assimilating context /tk/, intermediate for the control /kk/, and higher for the control /kt/. Results suggest that speakers have lexical knowledge of place assimilation, producing a greater tongue body gesture in the spatio-temporal domains with lower jaw height as an indication of anticipating reduction of C1 in /tk/ sequences.