• 대한구순구개열학회지
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• 제14권1_2호
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• pp.19-28
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• 2011

Maxillary anterior segmental distraction osteogenesis (DO) has been the alternative treatment option for patients with midfacial retrusion. The patient showed unilateral cleft lip and palate, and premaxillary distraction with rigid external device (RED) was planned to solve midface deficiency and to create alveolar space. Significant advancement of A point was observed, but relapse of A point was detected during consolidation period. The vertical position of the ANS was found to have moved downward. Axis of upper incisor decreased after DO. Maxillary anterior segmental DO is effective for treatment of patient with cleft lip and palate. The alveolar space is regained successfully, and the facial profile is improved without velopharyngeal problems.

• 대한치과보철학회지
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• 제29권3호
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• pp.141-170
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• 1991

This study was to analyze the displacement and the magnitude and mode of distribution of the stresses in the lower overdenture, the mucous membrane, the abutment teeth and the mandibular supporting bone when various abutment designs were subjected to different loading schemes. For this study, the two-dimensional finite element method was used. The models of overdenture and mandibe with the canine and the second premolar remaining, were fabricated. In the first design, a 1 mm space was prepared between the denture and the dome abutment with the height of 2 mm(OS). In the second design, a contact between the denture and the occlusal third of the dome abutment with the hight of 2 mm was prepared(OC). In the third design, a 0.5 mm space was prepared between the denture and 8 degree tapered cylindrical abutments with the height of 7 mm(TS). In the fourth design, a contact between the denture and the occlusal two thirds of the conical abutments with the height of 7 mm was prepared(TC). In order to represent the same physiological condition as the fixed areas of the mandible under loading schemes, the eight nodes which lie at the mandibular angle, the coronoid process and the mandibular condyle were assumed to be fixed. Each model was loaded with a magnitude of 10 Kgs on the first molar region (P1) and 7 Kgs on the central incisor region (P2) in a vertical direction. The force of 10 Kgs was then applied distributively from the first premolar to the second molar of each motel in a vertical direction (P3). The results were as follows: 1. The vertical load on the central incisor region(P2) produced the higher displacement and stress concentration than that on the posterior region(P1, P3). 2. The case of space between abutment and denture base produced higher displacement than that of contact, and the case of long abutment produced higher displacement than that of short abutment because of low rigidity of denture base. 3. The magnitude of the torque and vertical force to the abutment teeth and the stress distribution to the denture base was higher in the telescope coping than in the overdenture coping. 4. The vertical load on the central incisor region(P2) produced higher equivalent stress in the mandible than that on the posterior region(P1, P3). 5. The case of space between abutment and denture base produced better stress distribution to the farther abutment from the loading point than that of contact. 6. In case of sound abutment teeth, the type of telescope coping can be used, hilt in case of weak abutment, the type of overdenture coping is considered to be favorable generally.

• 대한치과교정학회지
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• 제29권4호
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• pp.399-409
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• 1999

본 연구는 교정치료동안의 전치부 후방이동에 의한 하안면부 연조직 측모 변화를 평가하기 위하여 시행되었다. 치조성 양악전돌을 주소로 내원하여 상, 하악 제 1 소구치를 발거하고 전치부 후방이동을 시행한 31증례의 치료전후 측모두부X선규격사진을 이용하였으며 성장의 영향을 배제하기 위하여 17세 이상의 한국인 여성으로 대상을 제한하였다. 치료전후 각 계측치와 변화량을 이용하여 paired f-test와 상관분석 및 회귀분석을 시행한 결과 다음과 같은 결론을 얻었다. $\cdot$치아의 후방이동량과 연조직의 후방이동량의 비는, 상악 중절치 (UIS):상순 (LS)은 1.54:1, 하악 중절치 (LIS):하순 (Ll)은 0.92:1이며 각각의 상관계수는 각각 0.746과 0.584로 나타났다. $\cdot$치료동안 연조직 자체의 두께는 상순 (UIS-LS)에서만 증가가 있었고 나머지 부위에서는 약간의 감소가 있었다. $\cdot$치아 이동량과 연조직 이동량간의 상관분석에서 상순 (LS)은 상악 중절치 (UIS)와 하순(LI)은 B점과 가장 높은 상관관계를 보였다. $\cdot$치아이동에 따른 하안면부 연조직의 이동을 예측하기 위한 다중 회귀방정식을 구할 수 있었다.

• 대한치과의사협회지
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• 제56권9호
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• pp.492-502
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• 2018

Anterior maxillary teeth play an important role in determining a person's first impression and facial profile. Implant surgery in esthetic area requires more careful diagnosis, treatment planning, surgery, and prosthetic restoration than in posterior area. To avoid complications in surgery and prosthetic restoration for implants in esthetic area, accurate diagnosis and appropriate case selection become very important. If you have decided to restore the area with implant prosthesis, you have to know exactly where to place an implant. I will discuss the ideal implant position in terms of mesio-distally, apico-coronally, labio-palatally, and implant angulation. And I would like to point out the selection of fixture diameter & length for anterior implant. Finally, a clinical implant prosthesis case in maxillary central incisor will be shown. In conclusion, for superior esthetic outcome in anterior implant prostheses, we must understand the patient's anatomic condition and know our ability.

• 대한두개안면성형외과학회지
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• 제13권1호
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• pp.4-10
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• 2012

Purpose: The objective of this retrospective study was to assess the skeletal stability after orthognathic surgery for patients with cleft lip and palate. The soft tissue changes in relation to the skeletal movement were also evaluated. Methods: Thirty one patients with cleft received orthognathic surgery by one surgeon at the Craniofacial Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan. Osseous and soft tissue landmarks were localized on lateral cephalograms taken at preoperative (T0), postoperative (T1), and after completion of orthodontic treatment (T2) stages. Surgical movement (T0.T1) and relapse (T1.T2) were measured and compared. Results: Mean anteroposterior horizontal advancement of maxilla at point A was 5.5 mm, and the mean horizontal relapse was 0.5 mm (9.1%). The degree of horizontal relapse was found to be correlated to the extent of maxillary advancement. Mean vertical lengthening of maxilla at point A was 3.2 mm, and the mean vertical relapse was 0.6 mm (18.8%). All cases had maxillary clockwise rotation with a mean of 4.4 degrees. The ratio for horizontal advancement of nasal tip/anterior nasal spine was 0.54/1, and the ratio of A' point/A point was 0.68/1 and 0.69/1 for the upper vermilion/upper incisor tip. Conclusion: Satisfactory skeletal stability with an acceptable relapse rate was obtained from this study. High soft tissue to skeletal tissue ratios were obtained. Two-jaw surgery, clockwise rotation, rigid fixation, and alar cinch suture appeared to be the contributing factors for favorable results.

• 대한소아치과학회지
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• 제36권3호
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• pp.412-419
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• 2009

혼합치열기 정상교합 아동 24명(남:14명, 여:10명, 초진 시 평균 나이 9${\pm}$1.3세, 평균 관찰 기간: 13${\pm}$1.3개월)에 대한 성장량을 측정하여 기능적 교정장치의 순수 치료효과를 평가하는데 도움이 되기 위해 3회(5${\sim}$8개월 간격) 촬영한 측모 두부방사선 규격 사진에 대한 분석 결과 다음과 같은 결론을 얻었다. 1. 남아는 상악골은 전하방, 하악골은 전방성장하였고, 여아는 상하악골이 전하방 성장하였다(p<0.05). 2. 상하악골의 남녀간 차이에서 수평적 성장상태는 여아가 컸고(A point 여아: 2.39mm, 남아: 1.26mm, p<0.05), 수직적 성장상태는 유의한 차이가 없었다. 3. 상악 전치의 치축은 두개저에 대해서 순측 경사하였고(p<0.01) 하악 전치의 치축은 큰 변화가 없었다.

• Imaging Science in Dentistry
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• 제38권4호
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• pp.203-208
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• 2008

Purpose : The purpose of this study was to develop a system for the measurement and simulation of the TMJ movement and to analyze the mandibular movement quantitatively. Materials and Methods : We devised patient-specific splints and a registration body for the TMJ movement tracking. The mandibular movements of the 12 subjects with facial deformity and 3 controls were obtained by using an optical tracking system and the patient-specific splints. The mandibular part was manually segmented from the CT volume data of a patient. Three-dimensional surface models of the maxilla and the mandible were constructed using the segmented data. The continuous movement of the mandible with respect to the maxilla could be simulated by applying the recorded positions sequentially. Trajectories of the selected reference points were calculated during simulation and analyzed. Results : The selected points were the most superior point of bilateral condyle, lower incisor point, and pogonion. There were significant differences (P<0.05) between control group and pre-surgical group in the maximum displacement of left superior condyle, lower incisor, and pogonion in vertical direction. Differences in the maximum lengths of the right and the left condyle were 0.59${\pm}$0.30 mm in pre-surgical group and 2.69${\pm}$2.63 mm in control group, which showed a significant difference (P<0.005). The maximum of differences between lengths of the right and the left calculated during one cycle also showed a significant difference between two groups (P<0.05). Conclusion : Significant differences in mandibular movements between the groups implies that facial deformity have an effect on the movement asymmetry of the mandible. (Korean J Oral Maxillofac Radiol 2008; 38 : 203-8)

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권5호
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• pp.386-393
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• 2009

Objectives: This study was performed to evaluate course of the inferior alveolar canal in the mandibular ramus and to find safety zone when ramal bone is harvested. Patients and Methods: From January, 2009 to February, 2009, the 20 patients who visited in the Department of Oral and Maxillofacial Surgery, Sanbon Dental Hospital. Wonkwang University and the Conebeam CT was taken of various chief complaints, were selected. The patients who had left and right mandibular first molar and incisor missing, jaw fracture and bone pathology were excluded. The R point was defined as the point which occlusal plane was crossed to the mandibular anterior ramus(external oblique ridge). In the cross-sectional coronal and axial views, the inferior alveolar canal position to the R point, buccal bone width(BW), alveolar crest distance(ACD), distance from alveolar crest to occlusal plane(COD) and inferior alveolar canal to sagittal plane(CS) were measured and horizontal distance(HD), vertical distance(VD) and nearest distance(ND) were measured. Results: The inferior alveolar canal is located $6.19{\pm}1.21\;mm$ from the R point. Horizontal distance from the R point were $13.07{\pm}2.45\;mm$, vertical distance from the R point were $14.24{\pm}2.41\;mm$ and nearest distance from the R point were $10.12{\pm}1.76\;mm$. The course of the inferior alveolar canal was positioned within $0.61{\pm}0.68\;mm$. The distance from external buccal bone to the inferior alveolar canal was increased from the R point anteriorly. Conclusions: It is considered that the mandibular ramus from the R point to 10 mm anteriorly can be harvested safely at ramal bone grafting.

• 한국치위생학회지
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• 제10권4호
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• pp.655-661
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• 2010

Objectives : This study is aimed to prevent the damage to the inferior alveolar nerve during the orthognathic surgery. Methods : The control group consist of 50 patients with class I occlusion. The experimental group consist of 50 patients with class III malocclusion. The cepalometric radiography was used to evaluate the position of the mental foramina. Results : In the first, mental foramen position of class III was more inferior 0.85 mm in the distance between base of mandible and mental foramen. But the distance between occlusal plan and mental foramen had not statistically significant. Secondly, mental foramen location of Mandibular Prognathism was more anterior 0.91 mm in the distance between coronal plane of mandible included pogonion point and mental foramen. Also, the distance of occlusal-coronal plane of mandible included central incisor and mental foramen had statistically significant. The mental foramen location of class III was more anterior 4.81 mm than class I patients. Conclusions : The result of this study could help the clinicians to apprehend fundamental data with various facial skeletal types for any related researches about the location of the mental foramina for other purposes.

• 대한치과보철학회지
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• 제34권4호
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• pp.780-790
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• 1996

The endodontically treated tooth is generally restored with post and core, owing to the brittleness and the loss of large amount of tooth structure. Although there have been lots of studies about the endodontically treated teeth, the three-dimensional quantitative studies about the stress distribution of them are in rare cases. In this study, it was assumed that the coronal portion of the upper incisor had extensively damaged. After the root canal therapy it was post cored, and restored with PFG crown. The three-dimensional model, in which the root was supported with a normal alveolar bone, was constructed. Force was applied to the centric stop point with the angle of 135 degrees to the long axis of the tooth. Force was assumed to be 250N as functional maximum bite force of upper central incisors. The results analyzed with three-dimensional finite element method were as follows : 1. Stress was concentrated on the middle portion of the labial side dentin and the apical portion of the dentin. 2. Stress in the post was more concentrated on the post apex. 3. The displacement of the post at the post-cement interface was almost symmetrical la-bio-lingually. 4. It assumed that restoring extensively damaged tooth with a post-core and PFG crown is an adequate method of restoration.