• 치과방사선
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• 제7권1호
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• pp.49-52
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• 1977

The authors had observed a case of cleidocranial dysostosis of 42 years old unmarried woman. The observation was founded upon roentgenogram of skull P-A view, orthopantomograph, cephalometric view, chest P-A view and wrist X-ray view. The patient gave a dwarfic impression with 145㎝ body height and concaved mandibular prognastic facial feature. The palate was narrowed and extremely high arched. The eruption state of teeth were extremely poor, only four teeth were erupted, composed of upper third molar and lower three deformed teeth. The skull P-A view of roentgenogram reveals overlying metopic suture, extends from the nasion to the sagittal suture, and the suture are delayed up to date and many wormian bones are formed. On the cephalometric view the maxilla is underdeveloped and produce the false mandibular prognathism. Twenty four impacted teeth can be detected by orthopantmograph, twelve in upper jaw and twelve in lower jaw. There are many supernumerary teeth, one in upper jaw and seven in lower jaw. On the chest P-A view, the clavicles are totally aplastic, but a vestige of clavicle is visible in the right side. On the wrist roentgenogram, the epiphyseal ossification of distal phalanx, mesial phalanx and proximal phalanx is delayed.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권6호
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• pp.490-496
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• 2011

Purpose: Dr. Marquardt made the facial 'phi' mask using golden ratio. Most class III patients have bulky faces and want a smaller face. Using a facial golden mask, this study estimated and compared frontal photographs before and after operation for soft tissue measurement. The golden mask can be considered as a reference tool for facial esthetic analyses especially in lower face. Methods: Forty patients who had undergone orthognathic surgery at Samsung Medical Center from January 2006 to December 2009 were included in this study. These patients had Class III malocclusion. Lateral cephalometric radiographs, frontal clinical photos of pre-op and 8~12 month later post-op, and the facial 'phi' mask using golden ratio, were used for analysis. Reduction of the lower face area, occlusal plane changes, amounts of mandible setback and amounts of maxilla posterior impaction were estimated. Results: Lower facial reduction ratio and mandibular setback amounts were significantly different between 1-jaw and 2-jaw groups. Average postoperative changes in the area of lower face between bilateral sagittal split ramus osteotomy (BSSRO) and BSSRO combined maxilla posterior impaction were compared by using an independent simple t-test and $P$ value was 0.016. Therefore, the lower facial reduction ratio and mandibular setback amount were significantly different in maxilla posterior impaction. Conclusion: The two-jaw surgery group showed more reduction of the lower facial area than the 1-jaw surgery group. The amount of lower facial reduction was more related with the amount of mandibular setback. There was no significant relation in lower facial reduction with amount of maxilla posterior impaction, pre-op occlusal plane, post-op occlusal plane and the mandibular angle. A relationship between the change in the lower facial area and the amount of maxilla posterior impaction or the change of mandibular angle occlusal plane at pre-op could not be found because of the difference in the amount of setback between two groups.

• 한국기계가공학회지
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• 제7권3호
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• pp.17-24
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• 2008

Rail clamps are mechanical components installed to fix the container crane to its lower members against wind blast or slip. According to rail clamps should be designed to survive harsh wind loading conditions. In this study, a jaw structure, which is a part of a wedge-typed rail clamp, is optimized with respect to its strength under a severe wind loading condition. According to the classification of structural optimization, the structural optimization of a jaw is included in the category of shape optimization. Conventional structural optimization methods have difficulties in defining complex shape design variables and preventing mesh distortions. To overcome the difficulties, the metamodel using Kriging interpolation method is introduced to replace the true response by an approximate one. This research presents the shape optimization of a jaw using iterative Kriging interpolation models and a 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.

• 치과방사선
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• 제10권1호
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• pp.15-28
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• 1980

The author studied age and sex distribution, etiology, affected site and several radiographic features of osteomyelitis of the jaw. And radiologic classification of osteomyelitis was also done. The material consisted of 118 males and 96 females examined and/or treated under the diagnosis of osteomyelitis during past 11 years (1970-1980.6) in SNUDH. The obtained results were as followings. 1. The incidence is the highest in teenages(22.9%) and the lowest in seventies. (2.8%). 2. 199 cases were found in lower jaw, and 15 cases in upper jaw. 30.8% of all cases were located at the posterior portion of mandibular body comprising alveolar region. 3. Radiographic examination of osteolytic lesion revealed that 21. 5% of all patients had periapical and alveolar bone rarefaction combined with osteoporotic changes and that in most of patients two or more of the above described changes were present at the same time. 4. Sclerotic lesions were seen in 62.2 % of all patients and 21.5% of sclerotic lesion were diffuse or homogenuous type. 5. Based on the radiologic study, classification of the osteomyelitis of the jaw was made. Loclized osteolytic type was the highest in incidence (38.8%) and localized sclerotic type was the lowest (7.0%)

• Imaging Science in Dentistry
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• 제49권3호
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• pp.235-240
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• 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.

• 대한치과보철학회지
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• 제37권4호
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• pp.516-530
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• 1999

The current clinical technique for occlusal vertical dimension recording is based on marking the skin reference points on the patient's face and measuring between these points using caliper-like device. And it is difficult to achieve reliable measurements by this technique because of movable soft tissue. The purpose of this study is to reveal the stability of skin reference points by comparing the relative movement between extra-oral skin reference points and intra-oral reference points using X-ray fluoroscope. 10 test subjects were divided into 2 groups : Group I (natural dentition) and Group II (denture-wearer whose vertical dimension was lost) and Group III consists of identical test subjects to Group II with their upper denture removed and record base inserted. Attaching the 3 mm diameter steel ball to nose tip, lower lip, chin and to existing denture (or record base), fluoroscopic examination and recording were taken during 2 jaw opening and closing movements. After subsequent digitization using personal computer, 1219 still pictures with 0.1 second interval were made. Using the 2 dimensional graphic software, measurements between reference points were executed. Dividing the entire jaw movement into 3 ranges (total, 1st half opening, 2nd half opening), rate of movement and relative movement between extra-oral and intra-oral reference points were calculated and statistically analyzed. The results of this study are as follows. 1 Within the same experimental group, no statistical difference was found in the stability of skin reference between lower lip point and chin point during total range of jaw opening and closing movement (p>.05) 2. In the first half range of jaw opening, statistical difference was found between Group I (natural dentition) and Group II (denture wearer) (p<.05) Group I has greater skin reference stability than Group II. 3. In the first half range of jaw opening, statistical difference was found between Group I and Group III (record base wearer) (p<.05). Group I has greater skin reference stability than Group III. 4. In the first half range of jaw opening, no statistical difference was found in the stability of skin reference between Group II and Group III (p>.05). 5. In the second half range of jaw opening, no statistical difference was found in the stability of skin reference between any experimental groups (p>.05). 6. In patients with their occlusal vertical dimension lost, employing other measuring references rather than skin is recommended because of low stability.

• 대한치과교정학회지
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• 제25권5호
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• pp.613-625
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• 1995

본 연구는 골격성 III급 부정교합 환자에서 술전 상태와 수술방법 사이의 관계 및 악교정 수술후 재발경향을 조사하기 위하여 시행하였다. 연구 대상으로는 악교정수술을 받은 31명(남자 17명, 여자 14명)을 선택하였고, 이중 20명은 편악수술, 11명은 양악수술을 시행하였으며, 평균연령은 22.5세였다. 각 대상에서 술전, 수술직후, 1년 이상 경과 후의 측모두부방사선 규격사진을 채득하여, 투사도를 작성하고, 분석하여 다음과 같은 결과를 얻었다. 1. 하악만을 수술한 군보다 양악 동시수술군에서 하악체의 길이가 4.24mm, 하안모 고경의 길이가4.64mn, 하순의 길이가 4.13mm 더 길게 나타났으며, 반면 수평피개도는 3.13mm 더 작게 나타났다. 2. 하악만을 수술한 군에서 $8.95\pm4.45mm$ 하악이 후방이동되었으며, 양악 동시수술군에서 상악은 $5.15\pm3.46mm$ 전방이동되었고, 하악은 $7.24\pm9.11mm$ 후방이동되었다. 3. 최소 1년 이상 경과 후와 수술직후의 변화에 있어서 양악 동시수술군에서 A point는 $1.02\pm2.14mm$, Pn에서는 $1.05\pm1.48mm$, Sn에서는 $1.55\pm1.37mm$ 후방이동되었다. 4. 최소 1년 이상 경과 후와 수술직후의 변화에 있어서 B point에서 하악만을 수술한 군은 $28\%$ 양악 동시수술군은 $8\%$, B' point에서 하악만을 수술한 군은 $24\%$, 양악 동시수술군은 $3\%$ 전방이동되었다.

• Journal of Radiation Protection and Research
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• 제44권4호
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• pp.156-160
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• 2019

Background: To compare the dose of radiation received by the fetus in a pregnant patient irradiated for head and neck cancer using helical tomotherapy and three-dimensional conformal radiation therapy (3DCRT). Materials and Methods: The patient was modeled with a humanoid phantom to mimic a gestation of 26 weeks. Radiotherapy with a total dose of 2 Gy was delivered with both tomotherapy (2.5 and 5.0 cm jaw size) and 3DCRT. The position of the fetus was predicted to be 45 cm from the field edge at the time of treatment. The delivered dose was measured according to the distance from the field edge and the fetus. Results and Discussion: The accumulated dose to the fetus was 1.6 cGy by 3DCRT and 2 and 2.3 cGy by the 2.5 and 5 cm jaw tomotherapy plans. For tomotherapy, the fetal dose with the 2.5 cm jaw was lower than that with the 5 cm jaw, although the radiation leakage was greater for 2.5 cm jaw plan due to the 1.5 fold longer beam-on time. At the uterine fundus, tomotherapy with a 5 cm jaw delivered the highest dose of 2.4 cGy. When the fetus moves up to 35 cm at the 29th week of gestation, the resultant fetal doses for 3DCRT and tomotherapy with 2.5 and 5 cm jaws were estimated as 2.1, 2.7, and 3.9 cGy, respectively. Conclusion: For tomotherapy, scattering radiation was more important due to the high monitor unit values. Therefore, selecting a smaller jaw size for tomotherapy may reduce the fetal dose. however, evaluation of risk should be individually performed for each patient.

• 대한치과의사협회지
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• 제12권5호
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• pp.345-346
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• 1974

Supernumerary tooth was found in the premolar region of lower jaw on the left.

• 대한후두음성언어의학회지
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• 제10권1호
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• pp.12-16
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• 1999

Background and Objectives : The common cause of voice disorders may be bad habits of phonation. faulty vocal habits might aggravate the voice disorder or make the dysphonia. Authors thought the analysis of faulty vocal habits might help to evaluate the causes and to choose the treatment methods in patients with dysphonia. Authors studied to evaluate which vocal habits were used in patients with dysphonia. Materials and Methods : Patients with dysphonia(N= 32) and person without dysphonia(N=20) were evaluated through pre-evaluation test by otolaryngologist and SLP. All subjects were evaluated accordingly Posture of body, expansion of cervical vein, excessive movements of thyroide prominence, position of tongue, tension of lower lip, tension of jaw, breathing pattern related with phonation. Results : In dysphonia group, we found 23 cases with tension of jaw, 15 cases with expansion of cervical vein, 7 cases with bad position of tongue, 3 cases with excessive movement of thyroid prominence and a lot of cases with bad breathing Pattern on Phonation. In control group, only 3 cases with bad position of tongue, 2 cases with tension of lower lip, 1 case with tension of jaw were found. Conclusions : More faulty vocal habits were found in dysphonia group. Authors thought faulty vocal habits could be the cause of dysphonia and aggravate the dysphonia and the control of vocal habits would be very important in patients with dysphonia.