• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권5호
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• pp.311-319
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• 2012

Purpose: The aim of this study is to evaluate the vertical changes of the lip and perioral soft tissue, following orthognathic surgery in skeletal class III patients by a cephalometric analysis of a cone beam computed tomography (CBCT). Methods: A total of 20 skeletal class III patients, who had bimaxillary surgery with Le Fort 1 osteotomy and bilateral sagittal split ramus osteotomy, were included in this study. The surgical plan for maxilla was posterosuperior impaction with the anterior nasal spine, as the rotation center. Further, the surgical plan for mandible was also posterosuperior movement. The soft tissue changes between lateral cephalogram and CBCT were compared. And the correlations between independent variables and dependent variables were evaluated. Results: There were no significant differences of the soft tissues changes between lateral cephalogram and CBCT. Upper lip philtrum length (SnLs), nasolabial angle increased and upper lip vermilion length (LsStms), lower lip length (StmiB'), lower lip vermilion length (StmiLi), lower lip philtrum length (LiB') and soft tissue lower facial height (SnMe') decreased after surgery. Change of SnLs (${\Delta}$SnLs) was influenced by vertical change of menton (${\Delta}$MeV), and change of LsStms (${\Delta}$LsStms) was influenced by upper lip thickness (ULT). Change of StmiLi' (${\Delta}$StmiLi') were influenced by preoperative overjet. Change of StmiB' (${\Delta}$StmiB') were influenced by preoperative overjet, vertical change of lower incisor (${\Delta}$L1V) and horizontal change of posterior nasal spine (${\Delta}$PNSH). Change of LiB' (${\Delta}$LiB') was influenced by ${\Delta}$L1V and ${\Delta}$PNSH. Change of SnMe' (${\Delta}$SnMe') was influenced by ${\Delta}$MeV, horizontal change of upper incisor (${\Delta}$U1H) and horizontal change of lower incisor (${\Delta}$L1H). ${\Delta}$Nasolabial angle was influenced by change of ULT (${\Delta}$ULT). Conclusion: Both soft tissues and hard tissues can be evaluated by CBCT. Posterosuperior rotation of maxillomandibular complex resulted in increase of upper lip philtrum length and nasolabial angle, while the upper lip vermilion length, lower lip philtrum length, lower lip vermilion length, and soft tissue lower facial height showed a decrease.

• 대한소아치과학회지
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• 제34권4호
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• pp.646-650
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• 2007

2003년 4월부터 2006년 4월까지 안양 지역에 위치한 개인 소아치과 병원에 내원한 환아 7038명을 대상으로 임상적, 방사선학적 검사를 통해 성별, 상악 정중과잉치의 수, 치관의 형태와 위치, 치관 방향을 조사하여 다음과 같은 결론을 얻었다. 1. 과잉치를 가진 환아는 239명으로 3.40%(총 241명, 3.42%)에 해당하였고 총 289개의 과잉치가 있었다. 2. 과잉치는 1개 있는 경우가 191명으로 가장 많았고, 2개 있는 경우도 48명 있었으며, 3개 이상 있는 경우는 없었다. 3. 상악 정중과잉치는 3.2:1로 여아보다 남아에서 호발하였다. 4. 과잉치는 왼쪽에 있는 경우가 55.4%로 약간 더 많았고, 모양은 원추형, 방향은 역위형이 가장 많았다. 5. 하악 정중과잉치는 2명에서 관찰되었다.

• Imaging Science in Dentistry
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• 제41권4호
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• pp.155-159
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• 2011

Purpose : This study was performed to determine the prevalence of maxillary canine impaction on a basis of a single panoramic radiograph in Bangladeshi population. Materials and Methods : A random sample of seven hundred panoramic radiographs was collected from the patient record of a dental clinic. All the selected panoramic radiographs were taken from January 2009 to August 2010 by a single panoramic radiograph machine with the same exposure time (19 seconds) for all radiographs. One hundred and twenty panoramic radiographs were excluded to minimize the selection bias. In a dim lit room, an observer assessed the radiographs on a standard radiographic light box. The position of the impacted maxillary canine was recorded in line with the longitudinal axis of a tooth using the edge of a metal ruler. Data were subsequently put on SPSS 11.5 software and chi-square (${\chi}^2$) tests were applied to find out the association. Results : Among 580 panoramic radiographs it was found that impacted maxillary canines were present in only 7 (1.2%) radiographs. A statistical significant difference was found between the age of the patients and the vertical position of the impacted canines (p=0.000) and between the age of the patients and the horizontal position of the impacted canines (p=0.003). Conclusion : The prevalence was found to be low compared with the present study from the limitation of panoramic image. Further study needs to include three-dimensional imaging modality.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제41권4호
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• pp.190-193
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• 2015

Objectives: A mesiodens appears most commonly as a supernumerary tooth impacted in the anterior maxilla. The purpose of this study is analyze mesiodens clinically. Materials and Methods: Gender, crown form, direction of impaction, relation to permanent incisors, and chief complaints of patients with extracted mesiodens were analyzed. Results: Patients were analyzed for motivation to visit the hospital; 85.4% of the patients were referred from other hospitals. Mesiodens was more common in males than in females (3.7:1), and 70.1% of patients had only one mesiodens, while 29.6% had two mesiodenses. Of the mesiodenses, 61.4% were of the aconical form, and the most common direction was upward (62.4%), followed by the normal position (26.0%) and the horizontal position (11.6%). The mesiodenses caused orthodontic problems with the permanent incisors in 46.3% of cases. Mesiodens associated with dentigerous cyst was rarely observed in our patient group. Conclusion: Mesiodens is more common in males than in females and often affects the permanent incisors. Thus, careful clinical and radiological evaluations of mesiodenses are important.

• Journal of Periodontal and Implant Science
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• 제29권3호
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• pp.693-703
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• 1999

Since they were introduced by Ward in 1923, periodontal dressing have been routinely used following the periodontal surgery to avoid pain, infection, desensitizing teeth, inhibiting food impaction of the surgical areas, and immobilizing injured areas. Recently, however, the value of periodontal dressings and their effects on periodontal wound healing have been questioned, several authors have been reported that the use of dressing has little influence on healing following periodontal surgical procedures. In addition, there is evidence that when good flap adaptation is achieved, the use of a periodontal dressing does not add to patient comfort nor promote healing. The purpose of this study was to evaluate patient postoperative pain experience and discomfort with and without the use of periodontal dressing following periodontal surgery. Twenty-eight patients, 11 male and 17 female. were selected for this study; The age range was 31 to 56, with an average of 40.2years. Patient selection was based on existence of two bilateral sites presenting similar periodontal involvement, as determined by clinical and radiographic assessment, and requiring comparable bilateral surgical procedures. Using a splitmouth dressing. one site received a periodontal dressing while the other site did not. Pain assessment was made according to a horizontal, rating scale(0-10). After at least a two-week period, the second surgical precedure was performed using the alternate postoperative treatment. At the conclusion of the trial, a self-administered questionnaire on postoperative experience was administered, and were asked of their preference of either, dressed or undressed. The results were as follows: 1. A similar trend for mean pain and discomfort scores as assessed by patients both dressed and salinetreated procedures was evident during 7-day postsurgical period. 2. Statistical analysis of differences between the dressed side and salinetreated side with respect to pain, discomfort and patient's experiences revealed that both treatment sides behaved similarly at any postoperative day(P>0.05). 3. Considering the patient's preference, on the basis of pain and discomfort experienced, 43% preferred the saline-mouthwash and 32% preferred the dressing, 25% showing no preference for either the dressing or the saline-mouthwash. There is evidence to support the use of a periodontal dressing in retention of an apically positioned flap by preventing coronal displacement, or its use to provide additional support to stabilize a free gingival graft. However, there will always be a use for periodontal dressing although routine use of dressings may decrease because of better surgical techniques and the use of antibacterial mouth rinses.

• International Journal of Automotive Technology
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• 제5권4호
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• pp.221-238
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• 2004

Wall interactions of direct injection spray were investigated using laser-sheet imaging, shadowgraphy, wetted footprint and phase Doppler interferometry techniques. A narrow-cone high-pressure swirl injector is used to inject iso-octane fuel onto a plate, which has three different impact angles inside a pressurized chamber. Heated air and plate conditions were compared with unheated cases. Injection interval was also varied in the heated case to compare dry- and wet- wall impingement behaviors. High-speed macroscopic Mie-scattering images showed that presence of wall and air temperature has only minor effect on the bulk spray structure and penetration speed for the narrow-cone injector tested. The overall bulk motions of the spray plume and its spatial position at a given time are basically unaffected until a few millimeters before impacting the wall. The surface properties of the impact surface, such as the temperature, the presence of a preexisting liquid film also have a small effect on the amount of wetting or the wetted footprint; however, they have strong influence on what occurs just after impact or after a film is formed. The shadowgraph in particular shows that the plate temperature has a significant effect on vapor phase propagation. Generally, 10-20% faster horizontal vapor phase propagation is observed along the wall at elevated temperature condition. For impingement onto a preexisting film, more splash and evaporation were also observed. Contrary to some preconceptions, there is no significant splashing and droplet rebounding from surfaces that are interposed in the path of the DI gasoline spray, especially for the oblique impact angle cases. There also appears to be a dense spray front consists of large sac spray droplets in the oblique impact angle cases. The bulk of the spray is not impacted on the surface, but rather is deflected by it The microscopic details as depicted by phase Doppler measurements show that the outcome of the droplet impaction events can be significantly influenced. Only droplets at the spray front have high enough Weber numbers for wall impact to wet, splash or rebound. Using the sign of vertical velocity, the time-resolved downward droplets and upward droplets are compared. The Weber number of upward moving droplets, which seldom exceeds unity, also decreases as the impact angle decreases, as the droplets tend to impact less and move along the wall in the deflected spray plume.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권1호
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• pp.21-26
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• 2006

Considering the skeletal class III malocclusion that complains of mandibular prognathism, there have been some studies of the mandibular change for comparing the changes of pre operative with post operative state. Nowadays it is common to do the orthognathic 2-jaw surgery for the correction of the maxillary deficiency, the post operative stability and the esthetics. We compare and analyze the changes of soft tissue around the nose and the lip with the changes in the direction and the amount of maxilla. Patients who were diagnosed as maxillofacial deformity and received orthognathic surgery of both jaws at Yongdong Severance hospital from 2001 through 2003 were included in this study. Their lateral cephalograms were analyzed, and the post operative change of hard tissue and soft tissue were studied. Upon analyzing the preoperative cephalograms and 6 month post operative cephalograms, there were significant in the vertical change of Labialis superius(Ls) and Stomion(Stm) in soft tissue in relation to the vertical change of skeletal landmarks (Anterior Nasal Spine, Subspinale, Prosthion, Incision Superious). In addition, there were no significance in horizontal movement of the skeletal landmarks among groups. In terms of hard tissue landmarks, group 3(maxillary posterior impaction and advancement surgery group) showed significantly greater change in the vertical movement of Anterior Nasal Spine(ANS), Subspinale(A), Prosthion(Pr), and Incision Superious(Is) compared with other groups. In terms of soft tissue change, group 3 showed more significant change in the vertical movement of Ls and Stm. This study calculated the changes of the skeletal and soft tissue landmarks in order to act as a guide in planning and performing the surgery and as a reference in predicting the postoperative change of facial appearance.

• 대한소아치과학회지
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• 제39권1호
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• pp.90-96
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• 2012

정중 과잉치(mesiodens)는 대개 상악 절치부에서 발견되며, 주로 구개측에 위치하는 경향이 있다. 정중 과잉치의 자연맹출 가능성이 관찰되면, 주기적으로 검사하여 구강내로 충분히 맹출한 후에 단순발치를 시행한다. 주기적 검사에서 자연맹출 소견이 보이지 않거나, 형태이상 혹은 맹출방향의 이상으로 구강 내로 자연맹출 할 가능성이 없으면, 수술적 제거방법을 고려해야 할 것이다. 특히, 인접한 중절치나 측절치의 맹출을 방해하고 있는 상황이 관찰된다면, 빠른 시일 내에 과잉치 제거를 위한 수술적 방법을 시도하는 것이 타당하다. 한편, 외과적 수술의 시기를 늦추는 것을 고려해야 하는 경우도 있다. 정중과잉치가 인접하여 발육중인 정상 치아의 맹출을 방해하지 않는 경우이다. 이때, 삼차원 CT사진을 촬영하여보면, 과잉치 주변으로 영구절치의 치배가 근접하여 성곽처럼 둘러싸고 있는 것을 볼 수 있다. 미성숙한 치배가 둘러 싸고 있는 상황에서, 무리하게 과잉치를 제거하려고 시도할 경우 인접 치배를 손상시킬 가능성을 배제하기 어렵다. 이 점을 고려 한다면, 가급적 인접한 치아의 치근이 보다 발육한 후에 수술을 시도하는 것이 바람직할 것이다. 초등학교 2학년 이상의 어린이들은 외래에서 국소마취하 제거하는 수술방법에 대개 잘 적응하며 고학년이 될수록 보다 수월해진다. 수술시기를 너무 늦추거나, 과잉치가 너무 늦게 발견된 경우 구개측 심부로 깊이 이동한 것을 볼 수 있다. 때로는 과잉치의 위치가 처음부터 심부에 매복되어 있을 수 있다. 이와 같은 경우, 전신마취방법을 생각해 볼 수 있을 것이다. 본 증례는 상악 정중부의 깊은 부위에 역위 매복된 과잉치를 외래에서 국소마취하에 치료를 시도할 때 관찰되는 문제점을 고찰하였고, 전신마취방법을 결정하기 위한 기준을 제시하였다. 심부 매복된 치아의 외과적 발거시 어린이의 행동조절이 가장 큰 문제였으며, 방사선 소견상 과잉치 치관의 위치가 절치의 치근단보다 상방에 위치할 경우 전신마취로 전환 하는 것이 바람직 할 것으로 사료된다.