• 한국전산구조공학회논문집
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• 제29권4호
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• pp.309-315
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• 2016

최근 치의학 분야에서도 인체에 대한 구조적이고 역학적인 이해를 위하여 유한요소해석 기법이 널리 사용되고 있다. 따라서 본 연구에서는 CT 이미지를 기반으로 하는 유한요소모델링 기법을 제안하고, 실험결과와 비교하여 검증하였다. 또한 제안된 해석기법을 통해 교합 시뮬레이션을 구현하여 정상 I급 교합과 Full-CUSP II급 교합상태의 두개골 모델에 대하여 기하비선형구조해석을 수행하였다. 그 결과, 하악골이 같은 거리만큼 이동할 때 사람의 실제 교합력 범위에서는 두 모델의 교합력에 큰 차이가 없는 것으로 나타났다. 그러나 응력분포를 비교했을 때 정상 I급 교합모델은 치아 및 치조골 전반에 응력이 균등하게 발생하는 반면, Full-CUSP II급 교합모델의 경우 일부 구역에 응력집중 현상이 나타났다. 이는 치아의 부재 및 재배열로 인하여 교합면이 달라지면서 생긴 결과라고 분석된다.

• 대한소아치과학회지
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• 제43권1호
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• pp.70-78
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• 2016

성장기 아동의 II급 부정교합의 치료에는 많은 악정형장치가 사용되어 왔으며 다양한 형태로 변화하여 발전되어 왔다. Headgear는 II급 부정교합 중 상악이 과성장된 경우 상악골의 성장 억제를 목적으로 사용하는 구외장치이다. Hotz 장치는 주로 II급 I류 부정교합 환자에서 cervical headgear와 함께 사용한다. 이 증례 보고는 상악의 과성장과 상악전치의 전향을 가진 3명의 II급 I류 부정교합 환자들에 관한 것이다. 모두 cervical headgear와 Hotz 장치를 이용하여 성장기에 악정형 치료를 시작하였다. cervical headgear와 Hotz 장치를 이용하여 치료한 후, 각 환자의 상황에 맞는 후속 치료를 다음과 같이 시행하였다: 고정식 교정장치, 유지 및 계속적 악정형 치료를 위한 class II activator, 기존의 Hotz 장치를 이용한 유지. 환자들을 악정형 치료하고 각각의 상황에 맞는 후속 치료를 하였으며 돌출된 안모와 상악전치 전향의 개선, 전치부 총생의 개선, 상악골 성장 억제 등 양호한 결과를 얻을 수 있었다.

• 대한치과교정학회지
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• 제25권5호
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• pp.511-523
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• 1995

Elastic Open Activator(E.O.A.)는 myodynamic activator의 일종으로서 장치의 아크릴 부위의 대폭적인 크기 감소로 환자가 거부감 없이 장시간 착용할 수 있는 장점을 가지며, 구강내에서 매우 느슨하게 장착되므로써 보다 적극적인 근기능 자극 효과를 나타내고, 구강 내외의 제 기능시 발휘되는 생리적인 힘을 효율적으로 치조골 및 악관절부에 전달시킨다. 특히 기능모체(functional matrix)를 효과적으로 차단하는 동시에 능동적으로 자극함으로써 많은 부정교합 증례에서 비발치에 의한 교정치료의 성공률을 높이는 것으로 사료된다. 이 연구는 혼합치열기 및 초기 영구치열기의 II급 부정교합 환자에게 사용된 E.0.A.의 치료효과를 구명하기 위하여 시행되었으며 경희의료원 교정과에 내원하여 II급 1류 및 2류 부정교합으로 진단되었던 각각 9명과 5명의 치료 전후 cephalogram 및 석고모형을 비교분석한 후 결과를 평가하여 다음과 같은 결론을 얻었다. 1. 상악골은 두 군 모두에서 정상적인 성장 양태를 유지하였다. 2. 하악골은 두 군 모두에서 크게 전하방 성장되었다. 3. 상악 전치는 II급 1류 부정교합자에서는 설측, II급 2류 부정교합자에서는 순측 경사되었고 두 군 모두에서 상하악 전치부 치조골 수직 성장이 억제되었다. 4. 하악 전치는 두 군 모두에서 약간 순측 경사되었다. 5. 두 군 모두에서 상, 하악 치궁의 확장이 일어났으며 II급 2류 부정교합자에서 가용 공극의 길이가 증가되었다.

• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.357-367
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• 1993

The purpose of this study was to evaluate the fracture strength of class II restored premolars with amalgam, posterior composite, amalgam - Ketac silver, resin - Ketac silver restorations at marginal ridge. Fifty extacted maxillary and mandibular premolar teeth that were caries free, fracture free, and restoration free were selected and randomly divided into five groups : Group 1 : 10 intact teeth, Group 2 : 10 teeth with class II cavities and restored with, amalgam, Group 3: 10 teeth with class II cavities and restored with posterior resin, Group 4 : 10 teeth with class II cavities and restored with amalgam - ketac silver, Group 5 : 10 teeth with class II cavities and restored with resin - Ketac silver. All teeth were mounted in base of dental stone within metal rings of 2cm diameter, exposing only the crown portion. Class II mesio - occlusal or disto - occlusal cavities were prepared into specimens of Group 2 through 5 by using a No. 710 fissure bur. The occlusal portion was prepared to a faciolingual width of 1.5mm and a pulpal depth of 1.5mm. The proximal protion was prepared to a faciolingual width of 4mm, a occlusogingival height of 4mm, and a gingival floor of 1.5mm. The teeth in Group 2 and 3 were resotored with silver amalgam apd posterior resin respectively. In Group 4 and 5, proximal portions were first filled with Ketac silver 1.5mm gingivally and remaining cavities were restored with amalgam and posterior resin respectively. All specimens were stored in 100 % relative humidity at $37^{\circ}C$ for 48 hours before testing. All teeth were subjected to a compressive load in a Universal Instron Testing Machine at marginal ridges. The loads required to fracture the restorations were recorded in killograms and the data obtained were subjected to statisticall analysis. The results were all follows : 1. The fracture strength of Group 1 which were unprepared were $100{\pm}10.1\;kg$ and the higher values than Group 2, 3, 4, 5 which were prepared and resotred. 2. In restored groups, Group 2 had the higher fracture strength($81.8{\pm}12.4\;kg$) than other groups and Group 4 had the lowest fracture strength($66.8{\pm}9.2kg$). 3. There were significant differences between fracture strength of between Group 1 and Group 3, 4, 5(P<0.05), but not significant difference between fracture strength of Group 2, 3, 4, 5(P>0.05).

• 대한치과교정학회지
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• 제25권6호
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• pp.665-674
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• 1995

The purpose of this study is to investigate the cephalometric characteristics of the open-bite patients with DJD of TMJ. The DJD open-bite cases were compared with normal samples and Class II open-bite cases with normal TMJ respectively. Twenty three open-bite patients with bilateral DJD of TMJ($13.9\~35.3$ yens old, Group I) were selected from the Department of Orthodontics, SNUDH. Group ll consisted of thirteen Class II open-bite cases($13.2\~27.4$ years old) with no TMD signs/symtoms and good condylar shapes. Group III samples were the forty eight healthy dental students who have Class I molar relationships with no history of orthodontic treatment, good facial balance and no TMD symptoms($20.0\~26.8$ years old). First, sixty measurements in the lateral cephalometric radiographs and analysis of variance(P<0.05, Scheffe) were used to compare these three groups. The seven measurements showed significant difference(p<0.05) between Group I and Group II. After analysis of variance, six of them were used for the discriminant analysis(Wilks' stepwise analysis) and the discrminant function for Group I/Group II was obtained. The results and conclusions were as follows : In most of the measurments, Group I and Group II showed the same skeletal and dental characteristics. But seven of the sixty measurements(FH-PP angle, SNB, FH-ArGo angle, articulare angle, genial angle, upper gonial angle and Ar-Go length) were significantly different(p<0.05) between Group I and Group II. These differences may be explained by the fact that in DJD cases the mandible rotated backward due to the shortening of the ramus following the degenerative destruction of condylar head and its surrounding structures. The resulting discriminant function was : $D={-0.120X}_1+{0.066X}_2+{0.144X}_3-{0.058X}_4+2000,\;where\;X_1=ArGo\;length(mm),\;X_2=SArGo\;angle(degree),\;X_3=FH-PP\;angle(degree),\;X_4=Gonial\;angle(degree)$. Mean of the group centroids was -0.555 and percent of the 'grouped' cases correctly classified was $88.89\%$.

• 대한소아치과학회지
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• 제26권1호
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• pp.126-132
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• 1999

저자는 전남대학병원 소아치과에 내원한 혼합치열기 II급 부정교합환아를 Activator와 Anterior high pull headgear로 치료하여 다음과 같은 결론을 얻었다. 1. 상악골의 전, 하방 성장을 억제하였다. 2. 하악골의 전방 전위 및 반시계방향 회전을 유도하였다. 3. Deep overbite와 large overjet이 개선되었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권2호
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• pp.94-99
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• 2010

The purpose of this study was to examine the soft tissue changes in skeletal class II patients after mandibular advancement by bilateral sagittal split ramus osteotomy (BSSRO). In Asian population, the incidence of skeletal class II malocclusion is lower than that of skeletal class III malocclusion unlike the caucasians. This study was conducted to figure out the ratio at which hard tissue and soft tissue changes after mandibular advancement by analyzing cephalograms of 13 patients that have undergone the mandibular advancement surgery. As a result, change ratios of Li, B', Pog' according to the movement of li, B, Pog were found to be 0.59, 1.06, 0.82. Also, vertical height of vermilion zone (Si-Vb) and lower lip and chin (Si-Me') were measured to evaluate vertical changes. Vermilion zone showed tendency to decrease by 1.02 mm on the average postoperatively, whereas vertical length of lower lip and chin showed tendency to increase by 3.57 mm on the average.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.17.1-17.5
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• 2019

Background: Class II malocclusion patients with hyperdivergent facial types are characterized by short mandibular body lengths and anterior open bite. Accordingly, the treatment for hyperdivergent skeletal class II malocclusion is a lengthening of the mandibular body length and a counterclockwise rotation of the mandible. To prevent post-operative relapse, botulinum toxin-A (BTX-A) injection can be a retention modality. Case presentation: A class II open-bite patient received BTX-A injection to the anterior belly of her digastric muscle for the prevention of post-operative relapse. The relapse was evaluated via a clinical examination and a lateral cephalometric radiograph after the completion of post-surgical orthodontic treatment. The patient showed stable occlusion without any signs of relapse at 15 months post-operatively. Conclusion: In this case presentation, a single injection into the anterior belly of the digastric muscle was sufficient for the prevention of post-operative open bite.

• 대한치과교정학회지
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• 제21권1호
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• pp.171-183
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• 1991

This investigation was designed to categorize Angle's class II malocclusion groups through analyzing horizontal and vertical components of craniofacial skeleton in Angle's class II malocclusion. The material selected for this study consisted in standard lateral cephalogram of two hundred and twenteen children, eighty eight boys and one hundred twenty four girls, aged 6 through 18 years, having Angle's class II malocclusion. On the basis of findings of this study, the following results were obtained. 1. In horizontal skeletal classifications, 16 groups were classified according to FMN-A-B, SE-FMN-A, Ba-SE-Me, Ba-Se/Ra P. The sequences that have relatively high frequency are as follows: a) Horizontal Group 16 b) Horizontal Group 12 c) Horizontal Group 13 d) Horizontal Group 9 & 15 2. In vertical skeletal classification, 8 groups were classified according to the PMV/PP, PMV/Occ. P. PMV/Mn. P. The sequences that relatively high frequency are as follows; a) Vertical Group A b) Vertical Group D c) Vertical Group C d) Vertical Group H 3. In vertical and horizontal skeletal classifications, the sequence that relatively high frequency are as follows; a) Group13-A b) Group16-A & 9-A c) Group12-A & 15-A d) Group16-C

• 대한치과교정학회지
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• 제23권1호
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• pp.123-136
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• 1993

The purpose of this report is to present the successful improvement of occlusal relationship and facial esthetics in class II division 1 malocclusion with severe labioversion of upper anterior teeth and severe overjet, and in class II malocclusion with infraversion of bilateral maxillary canines by MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, with upper second molar extraction. After treatment, there were natural contact points at canine and premolar regions, normal occlusal relation-ship and treatment results, satisfied the gnathologic concept, in this 2 cases. Compared with the routine treatment with premolar extraction, the treatment time and patients' discomfort were reduced. And the MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, resulted in reduction of the treatment time and getting the good treatment results. Consequently, the majot concerns in orthodontic treatment are appropriate diagnosis and treatment plan, so, the application of second molar extraction with appropriate case analysis and diagnosis is very helpful to orthodontic treatment.