• 대한치과교정학회지
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• 제28권3호
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• pp.343-351
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• 1998

본 연구는 비발치로 치료된 I급 부정교합 환자의 형태적 특성을 알아보고자 시행하였다. 비발치로 치료된 I급 부정교합 환자의 치료전과 치료후 안면형태를 평가하고 이를 교정치료를 받지 않은 정상군과 4개의 제 1소구치를 발거하고 치료한 I 급 부정교합 환자군과 비교하였다. Edgewise appliance와 MEAW를 사용하여 비발치로 치료한 환자로 치료후 비교적 양호한 안모와 교합을 갖는 환자 22명을 대상으로 하였다. 이들의 평균 연령은 14.7세 였고 평균 치료기간은 2.6년이었다 치료전과 치료후의 두부계측방사선 사진에서 32개의 계측점을 사용하여 24항목의 각도와 거리를 측정하였다. Student t-test를 시행하여 비발치군의 치료전과 치료후의 변화, 비발치군과 정상군의 차이, 그리고 비발치군과 발치군의 차이를 비교한 결과($p{\leq}0.05$), 다음의 결론을 얻었다. 1. 비발치로 치료한 I 급 부정교합 환자의 치료전 ODI는 $69.9^{\circ}$, APDI는 $82.1^{\circ}$, CF는$152^{\circ}$, EI는 $152^{\circ}$ 였다. 2. 비발치군의 골격형태는 정상군과 유사하였으나 정상군보다 큰 절치간각을 보였다. 3. 발치군은 비발치군보다 돌출된 안모와 작은 절치간각, 그리고 낮은 EI를 가지고 있었다. 4. 비발치군의 치료전,후 골격형태에는 큰 변화가 없었으나 치료후 상,하악 구치의 직립과 절치간각의 감소를 나타내었다.

• 대한치과교정학회지
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• 제41권4호
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• pp.237-254
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• 2011

설측의 연속호선과 분절호선의 3차원 유한요소 모델에서 레버암의 길이와 미니스크류의 위치를 달리하여 전치부 후방 견인 시의 변위 양상을 비교하였다. 구개 경사면 견인 시, 두 호선 공히 레버암이 짧을수록 전치부의 설측 경사 이동을, 20 mm인 경우 중절치의 치체 이동 및 견치의 치근 이동 양상을 나타냈다. 정중구개봉합부 견인 시의 변위양상은 구개 경사면의 경우와 유사하였으나, 레버암이 20 mm인 두 호선에서 절치의 치체 이동 및 연속호선에서 전치부의 함입 소견을 보였다. 호선 종류에 관계없이 레버암이 길어질수록 절치의 정출은 감소하였고, 구개 경사면에서의 견인인 경우와 함께 견치의 협측 변위가 증가하였으며, 분절호선에서 변위량이 많았다. 연속호선상의 제2소구치는 근심 경사 이동 및 함입 소견을, 대구치는 레버암이 길수록 원심 이동 및 협측 변위를 나타낸 반면, 분절호선상의 구치부도 3차원적 이동 양상을 나타냈으나 변위량은 미미하였다. 전치부 후방 견인 시 레버암 작용에 의해 절치의 경사 이동과 견치의 측방 이동 경향이 있었으며, 치체 이동을 위해서는 약 20 mm의 레버암을 추천할 수 있다. 또한 호선의 종류가 치열 변위 양상 및 변위량에 차이를 나타냈다.

• 구강회복응용과학지
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• 제19권2호
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• pp.57-67
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• 2003

Suppose that dental occlusion is related to body posture. We want to find out that improving occlusal balance may affect vibration and distribution of C.O.P. in which way, by measuring change of posture and center of gravity (center of pressure, C.O.P.) which plays important role in measuring balance sensation. Total 11 students at Kyung Hee dental college students, 4 females and 9 males (age: 23-30) participated in this test, who have normal occlusion (Angle's classification I), no TMJ problems. All of the participants have no tooth loss except 3rd molar, no prosthesis over single tooth restoration, no orthopedic problems which affect balance sensation, and no otorhinolaryngological problems. First, we registrated bite by centric relation, and then fabricated stabilization splint that is increased 3.5mm vertical dimension around premolar region. By F-scan (Tekscan Inc., Boston, Mass), we measured discrepancy of average contact pressure of left and right foot. And we also measured discrepancy of vibration of C.O.P(center of pressure). before setting stabilization splint and after wearing stabilization splint at intervals of 1 week, 2 weeks, 3 weeks after. In normal human beings, improved occlusal balance by stabilization splint leads to decrease of vibration of C.O.P. (P<0.05). One week after wearing stabilization splint, vibration of C.O.P. decreased reliably (P<0.05), two weeks after wearing stabilization splint, vibration of C.O.P. decreased similarly comparing to before wearing and one week after wearing. (P<0.05) After two weeks and three weeks, however, it was hard to find reliability. (P>0.05) Difference between average contact pressure of right and left foot also decreased. (P<0.05) We could find decrease after one week of wearing stabilization splint (P<0.05) and two weeks after, the decrease was more reliable than one week after. (P<0.05) After two weeks and three weeks, however, it was hard to find reliability. Improvement of occlusal balance leads to decrease of vibration of C.O.P. and decrease of difference between right and left average contact pressure.

• 구강회복응용과학지
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• 제27권3호
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• pp.293-304
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• 2011

구치부 가위교합을 개선하기 위한 여러 방법 중, 교정용 미니임플란트(OMI)와 조합된 Dragon helix를 이용한 방법이 이전에 소개된 바 있으며 이는 간접 골성고정원의 역할이 중요하다. 이에 본 연구에서는 간접골성고정원으로 사용된 OMI의 식립각도에 따라 나타나는 구치부의 치근에 나타나는 응력분포와 OMI의 표면에서의 응력 분포 및 변위를 유한요소 해석으로 비교하고자 하였다. 상악 제1대구치와 상악 제2소구치의 치근 사이에 OMI의 식립 각도를 골 표면에 대하여, $45^{\circ}$, $60^{\circ}$, $90^{\circ}$으로 변화시키면서 최대응력분포와 변위를 관찰하였다. OMI의 식립 각도가 $90^{\circ}$일 때 상악 제1대구치와 상악 제2대구치의 구개 치근첨에 최대응력분포가 나타났고, 상악 제1대구치에서는 협측으로 변위의 양이 가장 적게 나타났으며, 상악 제2대구치에서는 함입 및 구개측으로의 변위량이 가장 크게 나타났다. OMI에서는 식립각도가 감소됨에 따라 최대 응력분포가 나사첨 부분으로 이동되었으며, 그에 따라 OMI의 변위량은 증가하였다. 이상의 결과로 OMI의 식립각도가 $90^{\circ}$일 때 고정원의 역할이 최대가 되었으며, 구치부 가위교합의 개선 효과가 가장 크게 나타남을 알 수 있었다.

• 구강회복응용과학지
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• 제25권3호
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• pp.279-285
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• 2009

본 연구의 목적은 인산칼슘제제인 $MBCP^{(R)}$, $Polybone^{(R)}$을 발치와에 이식 후 치유 양상을 조직학적으로 관찰하는 것이다. 비글견의 소구치를 발치 후 발치와에 골이식재를 이식하였으며, 3개월간의 치유기간을 거친 후 조직표본을 제작하여 현미경으로 치유 양상을 관찰하였다. $MBCP^{(R)}$, $Polybone^{(R)}$은 조직학적으로 비슷한 치유 양상을 보였으며 이물반응이나 염증 반응 없이 신생골 생성을 유도하여 정상적인 치유를 도모하였다. 치유된 조직의 조직 계측학적 평가에서 신생골 비율은 골이식재를 이식하지 않은 대조군이 34.5%, $MBCP^{(R)}$는 28.4%, $Polybone^{(R)}$은 23.8%였으며, 골이식재를 포함한 전체 mineralized tissue의 비율은 각각 34.5%, 42.9%, 37.3% 였다. 이상의 결과에서 $MBCP^{(R)}$, $Polybone^{(R)}$은 발치와에 사용할 골이식재로 가치가 있는 것으로 생각된다.

• 구강회복응용과학지
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• 제26권1호
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• pp.59-68
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• 2010

최근 무치악 부위를 대신하여 광범위하게 식립되고 있는 치과용 임플란트는 높은 임상 성공률을 보이고 있으나 실패 가능성은 늘 존재하며 이는 예기치 않은 경우가 많다. 임플란트의 실패과 관련하여 여러 가지 요인들이 거론되고 있으나, 아직 논란의 여지가 있다. 본연구에서는 서울 보훈병원에서 2005-2006년에 하악 구치부위에 임플란트를 식립한 212명의 환자, 총 358개의 임플란트를 대상으로 환자의 연령, 임플란트 식립 부위, 시스템, 직경과 길이, 골이식 유무에 따른 생존율을 비교하였다. 각 요소에 따른 생존율을 SPSS chi-square test를 이용한 multi-variable analysis를 시행하여 관련성을 검증하였다. 연구 결과 3년간 98.3%의 누적 생존율을 보였으며, 조사한 요인 중 임플란트 직경만이 임플란트 생존율과 관련성이 있는 것으로 나타났다. 이는 넓은 직경의 임플란트가 주로 대체(rescue) 임플란트 혹은 골질이 좋지 않은 부위에 사용되는 경우가 많은 것이 원인으로 작용한 것으로 사료된다. 향후 임플란트의 성공과 관련하여 명확한 지표를 제공할 수 있는 지속적인 연구가 필요할 것이다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권4호
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• pp.245-248
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• 2003

The retraction of anterior teeth could be performed more easier by inducing of skeletal anchorage system rather than by conventional method on orthodontic treatment. But, we wonder how effective the system draws well without anchorage loss and draws anterior teeth aside posteriorly, and if the system can reduce the time, in comparison with the anchorage of posterior teeth. For that reason we have studied on the subject of patients, who were required the maximum anchorage on orthodontic treatment and the cases without crowding. The subjects of the experimental group are 35 areas of 20 people who were inserted miniscrews after Mx or Mn 1st premolar extracted. Also, the subjects of the control group are 81 areas of 45 people who were not inserted miniscrews. Compared the anchorage loss of experimental group with control one, we could get the result that the anchorage loss of experimental group is $1.034{\pm}0.891mm$ and control group is $2.790{\pm}1.882mm$(P<0.01). Compared the space closing time of experimental group with control one, we could get the result that the space closing time of experimental group is $369.40{\pm}110.81$days and control group is $406.56{\pm}231.63$days. But the result of comparing space closing time has no significance in statistics. We recognized that the experimental group is more faster than the control group in the canine retraction velocity from the result ; the speed of a experimental group has as much as $0.60{\pm}0.23mm/30days$ while the speed of a control group has $0.44{\pm}0.35mm/30days$(P<0.05). So, we could convince that orthodontic miniscrew is used effectively in the cases required the maximum anchorage.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제44권5호
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• pp.225-231
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• 2018

Objectives: The purpose of this study was to investigate the demographic and clinical characteristics of patients with medication-related osteonecrosis of the jaw (MRONJ) and to elucidate factors affecting recurrence in surgical treatment. Materials and Methods: A total of 51 patients who were diagnosed with MRONJ were analyzed according to demographic and clinical features and treatment results through a retrospective chart review from 2013 to 2017 in the Department of Oral and Maxillofacial Surgery, Korea University Anam Hospital, Seoul in Korea. Results: Alendronate composed the majority of medication doses (55.6%), followed by ibandronate (20.0%), risedronate (15.6%), and zoledronate (6.7%). Forty patients (88.9%) were given oral medication, and five patients (11.1%) were intravenously treated, and the mean duration of medication use was $61.1{\pm}42.9$ months. A total of 10 patients (22.2%) had a drug holiday before MRONJ-induced dental treatment lasting an average of $6.8{\pm}7.0$ months. MRONJ occurred 2.7 times more in the mandible, with 41 cases (73.2%) occurring in the mandible and 15 cases (26.8%) occurring in the maxilla, and the prevalence of affected posterior parts (premolar-molar) was six times greater than that of the anterior parts (incisor-canine) (48 cases vs 8 cases, 85.7% vs 14.3%). The most common dental cause of MRONJ was tooth extraction (69.6%). Regarding recurrence, there was no statistical difference in recurrence rate according to either site or stage. However, recurrence occurred in 4 out of 34 cases (11.8%) in the primary closure group and 9 out of 20 cases (45.0%) in the secondary healing group, and there was a statistical difference with respect to closure technique. Conclusion: The identified risk factors in patients taking bone resorption inhibitors can aid dental clinicians in ensuring prevention and proper treatment of MRONJ.

• 대한치과보철학회지
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• 제39권6호
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• pp.599-610
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• 2001

Due to an increasing interest in esthetics and concerns about toxic and allergic reactions to certain alloys, patients and dentists have been looking for metal-free tooth-colored restorations. Recent improvement in technology of new all-ceramic materials and composite materials has broadened the options for esthetic single crown restorations. The aim of this investigation was to study the fracture strength of the metal-free posterior single crowns fabricated using two recently introduced systems, Empress 2 ceramic and Targis-Vectris. Forty premolar-shaped stainless steel dies with the 1mm-wide circumferential shoulder were prepared. Ten cylindrical crowns having a diameter of 8.0mm and total height of 7.5mm were fabricated for each crown system respectively(PFM, Empress staining technique, Empress 2 layering technique, and Targis- Vectris). The crowns were filled with cement and placed on the stainless steel dies with firm finger pressure. The crowns were then stored in distilled water at room temperature for 24 hours before testing. The crowns were tested for fracture strength in an Instron universal testing machine (Instron 6022). With a crosshead speed of 1mm/min the center of the occlusal surface of the crown was loaded using a 4-mm-diameter stainless steel ball until fracture occurred. The fracture surfaces of the crowns were gold coated and examined using scanning electron microscopy(Jeol JSM-840 Joel Ltd., Akishima, Tokyo, Japan). Within the parameters of this study the following conclusions were drawn: 1. The mean fracture strength for PFM crowns was 5829(${\pm}906$)N; for Empress staining technique the fracture strength was 1697(${\pm}604$)N; for Empress 2 Layering technique the fracture strength was 1781N(${\pm}400$)N, and the fracture strength for Targis- Vectris was 3093(${\pm}475$)N. 2. The fracture strength of the PFM crowns was significantly higher than that of the Empress 2 and the Targis-Vectris crowns (P<0.05). 3. The fracture strength of the Targis-Vectris crowns was significantly higher than that of the Empress 2 crowns (P<0.05). 4. No statistical difference was found when Empress staining technique was compared with Empress 2 layering technique. 5. The SEM image of fracture surface of Empress 2 crown showed a very dense microstructure of the lithium disilicate crystals and the SEM image of fracture surface of Targis-Vectris crown showed indentations of Vectris and some fibers tom off from Vectris.

• Journal of Periodontal and Implant Science
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• 제34권1호
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• pp.101-112
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• 2004

Osseointegrated implnats have proven to be successful in both full and partial edentulous patients since the 1960s and recently have shown successful results when used to restore single tooth missing. However, in most studies reporting the success of single implants, single implants replacing anterior teeth are more frequently mentioned than posterior single implants. Moreover, in studies regarding posterior single implants, the replaced region seemed to be variable; the maxilla, mandible and areas from the first premolar to the second molar were mentioned. However, considering the difference in bone quality in the mandible and maxilla, and the increased occlusal force in the posterior region, the success rates in each region may be different. In this study, the cumulative success rates and amount of bone loss of single implants replacing the mandibular first and second molar, respectively, were compared and analyzed to come to the following conclusion. 1. The 20 (20 persons) single implants that were placed in the mandibular first molar region were all successful and showed a 100% 5 year cumulative success rate. Among the 27 (24 persons) single implants replacing the mandibular second molar, 8 failed (27.63%) showing a 5 year cumulative success rate of 70.37%. 2. Among the 8 failed implants, one showed symptoms of postoperative infection and one complained of parenthesia. 6 implants failed after functional loading; 5 showed mobility and one resulted in fixture fracture. 3. After the attachment of the prosthesis, there was no significant statistical difference regarding the marginal bone loss in group 1 and group 2 during the checkup period (P>0.05). In conclusion, restoration of the mandibular first molar using single implants was found to be an excellent treatment modality, and when replacing mandibular second molars with single implants, poor bone quality and risk of overloading must be considered.