• 대한소아치과학회지
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• 제44권4호
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• pp.397-402
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• 2017

본 연구의 목적은 화성시에 거주하는 유치열기 어린이의 전치부 공극과 총생에 대해 알아보는 것이다. 한 명의 소아치과 전문의가 만 3 - 4세 유치열기 어린이들의 구강 내 임상 사진을 촬영하였으며, 400명 중 237명이 포함 기준을 충족하였다. 전치부 공극의 유무는 인접면 접촉의 유무로 판단하였다. 상악에서 생리적 치간 공극이 관찰되는 어린이는 47.3%였으며, 하악에서는 38.0%였다. 양악 모두에서 접촉 혹은 총생의 치열을 보이는 어린이는 43.5%였다. 여아보다 남아에서 생리적 치간공극이 존재하는 경우가 더 많았다. 상악에서는 영장류 공간이 발육공간에 비해 더 많이 발견되었으나, 하악에서는 그 차이가 적었다. 상악에서는 유중절치 사이에 공극이 있는 경우보다 유중절치와 유측절치 사이에 공극이 있는 어린이가 더 많았으며, 반면 하악에서는 유중절치 사이에 공극이 있는 어린이가 유중절치와 유측절치 사이 혹은 유측절치와 유견치 사이에 공극이 있는 어린이보다 많았다. 본 연구를 통해 3 - 4세 유치열기 어린이의 전치부 공극과 총생의 정도를 파악할 수 있었으며, 추후 더 많은 표본으로 조사가 필요할 것으로 사료된다. 유치열기의 전치부 공극 혹은 총생은 어린이 개인에 따라, 성별에 따라, 악궁에 따라, 치간 위치에 따라 다른 정도를 보이므로, 치과의사는 유치의 치관부를 수복할 때 이에 대한 인식 하에 치료를 시행하여야 한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권3호
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• pp.229-237
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• 2000

According to the functional matrix theory, Delaire proposes that individual occlusal plane was determined by variable effects of teeth, maxilla, mandible, cranium, cranial base and soft tissue matrix including the orofacial musculature. and that there is the ideal occlusal plane determined by the most proper spatial position of maxilla and mandible, functionally and esthetically. This study was designed to find out the relation between Delaire's ideal occlusal plane and muscle activity of masticatory muscles in individuals who have normal maxillo-mandibular relationships. Lateral cephalometric radiographs were taken and his/her individual occlusal plane and ideal occlusal plane were analyzed with Delaire's architectural and structural craniofacial analytic method. For evaluation of muscle activities of masticatory muscles, electromyography of anterior temporal muscle, superficial masseter muscle, and anterior belly of digastric muscle was recorded in fifty Korean normal Angle class I occlusion individuals. According to the average value of ideal occlusal plane, fifty normal Angle class I occlusion individuals were classified into three groups: Ideal occlusal plane group(I group), hyperrotation group(I+ group) and hyporotation group(I- group). The result of this study was as follows: 1. The results of Delaire's architectural and structural craniofacial analysis of lateral cephalography of the fifty Korean normal Angle class I occlusion individuals are that twelve persons(24%) have consistent or parallel with ideal occlusal plane and the average of angular difference was $1.22^{\circ}{\pm}3.69^{\circ}$. 2. There is no significant difference in muscle activities of masticatory muscles during resting(p<0.05), but significant increases of muscle activity of ipsilateral anterior temporal and masseter muscle, contralateral anterior belly of digastric muscle during unilateral chewing and of anterior temporal and masseter muscle during bilateral clenching(p<0.05). 3. To find out the effect of the angular difference between Delaire's ideal occlusal plane and real occlusal plane to muscle activity, muscle activities of masticatory muscles were compared with three groups in each other; I group, I+ group and I- group. The results were no significant differences during resting, unilateral chewing and bilateral clenching.(p>0.05) 4. Although there is no significant differences of masticatory muscle activities among the three groups, the fact that increasing tendency of masseter muscle activity of ideal occlusal plane group(I+) than those of any other groups(I+ and I-) during bilateral clenching was noted. There is only the implication that occlusal plane makes some effects on masticatory muscle activities, espacially that of masseter muscle during bilateral clenching. In conclusion, the hypothesis that occlusal plane is one of the factors which affect the muscle activities of masticatory muscles and that anyone whose occlusal plane consistent with Delaire's ideal occlusal plane has an extraordinary functional advantage in masticatory muscle function cannot be proven with electromyography methods.

• 대한치과교정학회지
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• 제47권2호
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• pp.118-129
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• 2017

Objective: To evaluate the effects of facemask therapy, which was anchored from the zygomatic buttresses of the maxilla by using two miniplates, in skeletal Class III patients with maxillary deficiency. Methods: Eighteen skeletal Class III patients (10 girls and 8 boys; mean age, $11.4{\pm}1.28$ years) with maxillary deficiency were treated using miniplate-anchored facemasks, and their outcomes were compared with those of a Class III control group (9 girls and 9 boys; mean age, $10.6{\pm}1.12$ years). Two I-shaped miniplates were placed on the right and left zygomatic buttresses of the maxilla, and a facemask was applied with a 400 g force per side. Intragroup comparisons were made using the Wilcoxon test, and intergroup comparisons were made using the Mann-Whitney U-test (p < 0.05). Results: In the treatment group, the maxilla moved 3.3 mm forward, the mandible showed posterior rotation by $1.5^{\circ}$, and the lower incisors were retroclined after treatment. These results were significantly different from those in the control group (p < 0.05). No significant anterior rotation of the palatal plane was observed after treatment. Moreover, changes in the sagittal positions of the maxillary incisors and molars were similar between the treatment and control groups. Conclusions: Skeletally anchored facemask therapy is an effective method for correcting Class III malocclusions, which also minimizes the undesired dental side effects of conventional methods in the maxilla.

• Journal of Radiation Protection and Research
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• 제48권1호
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• pp.15-19
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• 2023

Background: Cone beam computed tomography (CBCT) is a specialized medical equipment and plays a significant role in the diagnosis of oral and maxillofacial diseases and abnormalities; however, it is attributed to risk of exposure of ionizing radiation. The aim of the study was to estimate and determine the amount of scattered radiation dose to the thyroid gland in dental CBCT during maxilla and mandible scan. Materials and Methods: The average scattered radiation dose for i-CAT 17-19 Platinum CBCT (Imaging Sciences International) was measured using a Multi-O-Meter (Unfors Instruments), placed at the patient's neck on the skin surface of the thyroid cartilage, with an exposure parameter of 120 kVp and 37.07 mAs. The surface entrance dose was noted using the Multi-O-Meter, which was placed at the time of the scan at the level of the thyroid gland on the anterior surface of the neck. Results and Discussion: The surface entrance dose to the thyroid from both jaws scans was 191.491±78.486 µGy for 0.25 mm voxel and 26.9 seconds, and 153.670±74.041 µGy from the mandible scan, whereas from the maxilla scan the surface entrance dose was 5.259±10.691 µGy. Conclusion: The surface entrance doses to the thyroid gland from imaging of both the jaws, and also from imaging of the maxilla and mandible alone were within the threshold limit. The surface entrance dose and effective dose in CBCT were dependent on the exposure parameters (kVp and mAs), scan length, and field of view. To further reduce the radiation dose, care should be taken in selecting an appropriate protocol as well as the provision of providing shielding to the thyroid gland.

• 대한치과보철학회지
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• 제43권2호
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• pp.191-203
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• 2005

Statement of problem. In Korea, the preliminary impression trays for dental and edentulous maxillae are manufactured on the base of the statistical value of Westerners. There had been less study on the dental and edentulous arches of Koreans. Purpose. The purpose of this study was to evaluate an average dental cast, preliminary impression trays, three-dimensional relation of dental and edentulous maxilla of Koreans Material and methods. The subjects for this study were 173 dental casts of maxilla (dental: 52, edentulous : 146) with ages $18\{\sim}60$ years old. Each of the master casts was measured 69 measuring points on the dental cast or maxilla, and 46 measuring points on the edentulous cast of maxilla with three-dimensional digital measuring machine. Each measuring points were analysed and were overlapped, that three dimensional dental graphic manufactured by CAD/CAM system. Results. 1. A standard of distribution to alveolar bone were width between left and right buccal border lines of the standard 3/4 line. The mean value of dental and edentulous casts were 67.27mm, 63.49mm respectively. 2. Morphological classification of dental casts were divided into three groups or V-shape, O-shape, U-shape, that proportion of distribution were 17%, 16%, 67%, respectively. Dimensional classification of the dental casts were divided into five groups of less than 63mm, 63 up to 65mm, 65 up to 67mm. 67 up to 69mm, more than 69mm, respectively. 3. Morphological classification of edentulous casts were divided into three groups or V-shape, O-shape, U-shape, that proportion of distribution were 18%, 17%, 65%, respectively Dimensional classification of the edentulous casts were divided into five groups of less than 57mm, 57 up to 61mm, 61 up to 65mm, 65 up to 69mm, more than 69mm, respectively. 4. Mean dental and edentulous cast of maxilla were overlapped, the proportion of bone resorption to alveolar bone is higher than that of palatal bone, its difference were higher anterior 2/4 area than posterior 3/4 area. Conclusion. It obtains information of preliminary impression trays for dental and edentulous maxilla of Koreans.

• 대한치과교정학회지
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• 제4권1호
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• pp.49-55
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• 1974

The author studied the open-bite of 16 males and 25 females aged 20-23 using profile cephalometric roentgenogram and compared with normal occlusion to determine the morphological pattern of open-bite. The following results are obtained. 1) Open-bite patients showed remarkable vertical development of jaws than normal occlusion. 2) Females indicated conspicuous characteristics than males in open-bite. 3) Anterior teeth disclosed low positions in open-bite patients. 4) Mandible revealed obvious morphological features than maxilla in open-bite patients.

• 대한치과의사협회지
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• 제42권6호통권421호
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• pp.409-413
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• 2004

Tooth ankylosis is frequently resulted from trauma. If indicated, surgical correction is useful osteotomy is one of the method orthodontic surgery that realigns each tooth to the desirable position by using interdental alveolotomy. This method is being adapted when conventional orthodontic of tooth ankylosis on the anterior maxilla via unitooth osteotomy with literature review.

• 대한치과교정학회지
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• 제7권1호
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• pp.23-29
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• 1977

A 23 year-old female with skeleto-dentoalveolar protrusion of maxilla, minor broken contact points between anterior teeth, and missing of lower 1st molars, has been treated with multibanded edgewise technique. After treatment of 14 months, she has gained functional overbite-overjet relationship and facial harmony due to the retraction of upper anterior teeth. Root resorption was slight. Especially, us ing the space of missed lower 1st molars instead of extracting lower premolars, expected and favorable results were obtained.

• 대한치과의사협회지
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• 제16권3호통권106호
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• pp.199-204
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• 1978

The patient, 8 years female, complained of crossbite of anterior teeth and prognathism of mandible. There was lingual tipping of upper lateral incisor in teeth lining. Cephalometric analysis revealed normal in maxilla, but forward relation to standard, so daignosised as skeletal class III case. Crossbite of anterior teeth was corrected by means of CIII elastics under multibanded system. Space for eruption of canine was regained by means of E.O.A. After 2 years and 7 months, she gained good interdigitation of buccal segments of attractive facial profile.

• 대한치과교정학회지
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• 제21권3호
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• pp.701-709
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• 1991

This paper presents 2 clinical cases of facial asymmetry resulted from vertical asymmetry of the maxilla and unilateral hyperplasia of the mandibular condyle. Both patients, a 27 year 4 month old female and a 17 year 1 month old male, had a anterior crossbite with deviated dental midline and a concave profile. Both cases were treated with orthodontic and orthognathic procedure. The following results were obtained; 1. The facial asymmetry was favorably corrected. 2. The concave profile was improved. 3. The anterior crossbite was corrected. 4. The upper and lower dental midlines against the facial midline were corrected. 5. The functional overbite and overjet were established.