• The Journal of Advanced Prosthodontics
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• 제9권5호
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• pp.321-327
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• 2017

PURPOSE. The aim of this study was to investigate dental arch dimensions and to classify arch shape in Korean young adults. MATERIALS AND METHODS. The sample included 50 Koreans with age ranging from 24 to 32 years. Maxillary and mandibular casts were fabricated using irreversible hydrocolloid and type III dental stones. Incisor-canine distance, $incisor-1^{st}$ molar distance, $incisor-2^{nd}$ molar distance, intercanine distance, $inter-1^{st}$ molar distance, and $inter-2^{nd}$ molar distance in both the maxillary and mandibular arch were measured using a three-dimensional measuring device. The dental arch was classified into three groups using five ratios from the measured values by the K-means clustering method. The data were analyzed with one-way analysis of variance. RESULTS. Arch lengths (IM2D, $incisal-2^{nd}$ molar distance) were 44.13 mm in the maxilla and 40.40 mm in the mandible. Arch widths (M2W, inter $2^{nd}$ molar width) were 64.12 mm in the maxilla and 56.37 mm in the mandible. Distribution of the dental arch form was mostly ovoid shape (maxilla 52% and mandible 56%), followed by the V-shape and the U-shape. The arch width for the U-shape was broader than for the other forms. CONCLUSION. This study establishes new reference data for dental arch dimensions for young Korean adults. The most common arch form is the ovoid type in the maxilla and mandible of Koreans. Clinicians should be aware of these references and classify arch type before and during their dental treatment for effective and harmonized results in Koreans.

• 대한소아치과학회지
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• 제28권2호
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• pp.300-309
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• 2001

소도시에 거주하는 미취학 아동을 대상으로 하여, 유치열의 우식 발생 빈도와 양상을 조사하였다. 밀양시에 거주하는 624 명의 유치원 아동을 대상으로 dmf index를 사용하여 개개 치아와 치면별로 우식 발생 양상을 조사한 결과, 아래와 같은 결론을 얻었다. 1. 유치우식경험자율(dmf rate)은 3세에서 74.0%, 4세에서 83.8%, 5세에서는 90.6%였으며, 우식경험유치지수(dmft index)는 3세에서 3.47개, 4세에서 5.41개, 5세에서는 6.01개로 나타났다. 2. 5세 아동에 있어서 우식 경험률은, 하악 제2유구치, 하악 제1유구치, 상악 제2유구치, 상악 유중절치, 상악 제1유구치의 순으로 나타났다. 3. 3세 아동의 경우, 상악 유중절치의 우식이 가장 높은 빈도로 나타났으나, 연령증가와 함께 유구치 우식이 현저하게 증가하여, 5세 아동에서는 유구치 우식이 가장 높은 빈도로 나타났다. 4. 유전치와 유구치는 우식 발생 양상에 있어서 차이를 보였는데, 유전치의 경우에는 인접면 우식이 호발한 반면, 유구치에서는 교합면 우식이 더 높은 빈도로 나타났다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제13권4호
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• pp.462-467
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• 1991

Aspergillus is a fungus of Ascomycetes class that occurs world wide and found in many of the molds on foods, frutis, grains and plants. Its ubiquitous spores, present in dust, enter the respiratory system of man, where, under proper condition, they become pathogenic. We present a case of primary maxillary sinus aspergillosis developed from a 52-year old male patient when has oroantral fistula after extraction of maxillary Lt. 1st molar tooth. The treatment composed with Caldwell-Luc's operation, Oro-antral fistula closure and associated anit-fungal treatment with Amphoatrisin B.

• 대한치과교정학회지
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• 제18권2호
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• pp.435-447
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• 1988

This study was performed to evaluate the effect of low-power laser irradiation on the periodontium of the orthodontically moved tooth of rat. The experimental materials were 30 male rats. Orthodontic appliances were placed bilaterally between maxillary first molar and incisor teeth and the force was 1 Oz. Experimental animals were divided into eight groups as follows: no movement, 1st, 2nd, 3rd, 5th, 7th, 14th, and 28th day groups. In all experimental animals except no movement group, low-power laser was irradiated on the unilateral maxillary first molar (experimental side), but on the contralateral side, only orthodontic force was applied (control side). The histologic effects of laser on the periodontium of the orthodontically moved tooth on the consecutive experimental days were as follows: In the experimental side, by the biostimulating effect of laser, 1. Hyalinized tissue was formed later and eliminated earlier than in the control side. 2. Undermining bone resorption was occurred earlier than in the control side. 3. More osteoid tissue was deposited and calcified earlier than in the control side. 4. The most prominent changes were formation of new blood vessels and dilatation of old blood vessels.

• 대한치과교정학회지
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• 제26권5호
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• pp.523-534
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• 1996

성장기 아동의 ClassII 부정교합에서 과도한 성장의 억제, 미약한 성장의 촉진으로 성장 시기에 적절히 치료하는 것이 가장 효과적이며 좋은 치료 방법이다. 이러한 방법중 가장 적절히 쓰이는 장치 중 Cervical headgear의 사용을 들수 있으며 악골에 효과적으로 적용된다. 그러나 장치의 부작용이라 할 수 있는 수직적 성장의 과잉을 볼 수 있는데 이에 대해 많은 선학들의 연구가 시행되어 왔다. 본 연구는 Cervial headgear의 상하악골에 대한 효과를 분석하고 Lover facial height를 기준으로 증가군(>0)과 증가하지 않은 군 (${\leq}0$)으로 나누어 골격적 특성을 알아보기 위해 단국대학교 부속 치과병원에 내원한 성장기 아동의 II급 부정교합환자 25명을 대상으로 cervical headgear를 사용한 결과 다음과 같이 다소의 지 견을 얻었기에 보고하는 바이다. 1. 상악골의 전방 성분이 억제되었고, 구개 평면의 전방이 하방으로 tipping되었으며 상악 제 1대구치의 후방 이동이 있었다. 2. 하악골의 두개저에 대한 상대적인 전방 이동이 있었으며 상악에 대한 하악 제 1대구치의 상대적인 전방 이동이있었고 하악골의 alveolar growth에 의한 수직적인 증가가 있었다. 3. 전안면 고경과 후안면 고경이 각기 유의하게 증가했으나 안면 고경 비율에는 유의성이 없었다. 4. Lower facial height가 증가한 group이 증가하지 않은 group보다 ramus의 길이가 짧고 palatal plane angle이 더 작았으며 상악 제 1대구치의 후방 이동량이 더 많았다

• 대한치과교정학회지
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• 제24권4호
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• pp.787-798
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• 1994

The purpose of this study was three-fold: i) to investigate the degree of asymmetry in Angle's Class III malocclusion patients and normal adults; ii) to determine the nature of difference existed between two groups; and iii) to investigate the correlationship between the degree of asymmetry and ANB and overbite in Angle's Class III malocclusion patients. The subjects consisted of 25 Angle's Class III malocclusion patients and 25 normal adults and the mean ages were 22.0 and 24.5 years, respectively. Their posteroanterior and lateral cephalograms were traced and analysed with three-dimensional approach. The results were as follows: 1. Asymmetry of Angle's Class III malocclusion group was significant in all regions except cranial base. Their horizontal asymmetry was seen in mandibular angle, maxillary and mandibular 1st molar, mandibular midline and menton. Vertical asymmetry was observed in maxillary 1st molar and mandibular shape and anteroposterior asymmetry in mandibular angle. 2. Nine variables indicating asymmetry were selected and each variable had similar discriminant score. 3. There was a little correlationship between An and asymmetric variable(MSR-B6) and its correlation coefficients was 0.3564. 4. There was no significant correlationship between overbite and asymmetric variables.

• 대한치과교정학회지
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• 제24권2호
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• pp.247-273
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• 1994

The purpose of this study was to evaluate the dental arch morphology and the occlusal characteristics in the Koreans from the dental-anthropological point of view. The sample consisted of dental stone casts obtained from 120 Korean adults and 142 Japanese adults. Japanese casts and Caucasian data had been preserved at the Dept, of Orthodontics of Tokyo Medical and Dental University. Tooth size and dental arch morphology of the Koreans were compared with that of the Japanese. On the other hand, the variations of 30 crown traits, categorized and quantitatively graded, were compared between two peoples and the frequency distribution of each crown traits were analyzed by means of Chi-square test. The results were summerized as followings ; 1. There was a significant sexual difference in dental arch length and width in the Korean, in which male had a longer and wider dental arch than female. There was a close resemblance for dental arch morphology between the Koreans and the Japanese, except for a little longer mandibular arch of the Japanese. 2. In general, Korean male had wider crown than female, particulary in central incisor,canine,1st molar of maxilla and canine, 1st and 2nd molar of mandible with significance. The Korean had wider maxillary first molar, smaller mandibular first and second molar than the Japanese in both sex. 3. In crown traits of the Korean, shovel-shaped incisor showed lower frequency distribution than in the Japanese, but higher than in the Caucasians. Frequency of incisor reduction was shown higher distribution than in the Japanese and the Caucasians. Carabelli's tubercle showed higher frequency distribution than in Japanese, but remarkably lower than in Caucasians.

• 대한치과교정학회지
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• 제46권4호
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• pp.242-252
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• 2016

Objective: Orthodontic mini-implants (OMI) generate various horizontal and vertical force vectors and moments according to their insertion positions. This study aimed to help select ideal biomechanics during maxillary incisor retraction by varying the length in the anterior retraction hook (ARH) and OMI position. Methods: Two extraction models were constructed to analyze the three-dimentional finite element: a first premolar extraction model (Model 1, M1) and a residual 1-mm space post-extraction model (Model 2, M2). The OMI position was set at a height of 8 mm from the arch wire between the second maxillary premolar and the first molar (low OMI traction) or at a 12-mm height in the mesial second maxillary premolar (high OMI traction). Retraction force vectors of 200 g from the ARH (-1, +1, +3, and +6 mm) at low or high OMI traction were resolved into X-, Y-, and Z-axis components. Results: In M1 (low and high OMI traction) and M2 (low OMI traction), the maxillary incisor tip was extruded, but the apex was intruded, and the occlusal plane was rotated clockwise. Significant intrusion and counter-clockwise rotation in the occlusal plane were observed under high OMI traction and -1 mm ARH in M2. Conclusions: This study observed orthodontic tooth movement according to the OMI position and ARH height, and M2 under high OMI traction with short ARH showed retraction with maxillary incisor intrusion.

• 구강회복응용과학지
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• 제17권4호
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• pp.257-274
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• 2001

To properly prepare teeth, dentists require a direct view of the working area and are often placed in a difficult position, moreover, a high proportion of dentists suffer from headache and back pain. Dentists who make use of the dental mirror and position their patients carefully to gain a proper view report less headache, pain and discomfort in the shoulders. It is recommended that dentists learn the "Home Position(H.P.)" which among the various "Random Position(R.P.)" methods, enables dentists to approach their patients in a stable posture. The purpose of this study was to compare tooth preparation in the H.P. and the R.P., and evaluate the clinical efficacy of the H.P.. Tooth preparation for a full cast crown was performed on the maxillary left 1st molar using the H.P. and the R.P., and the shapes of the prepared tooth surfaces at the two different operating positions were compared. The amount of occlusal reduction, marginal width, height, and axial taper were measured and analyzed. A T-test was performed separately to compare the results of the H.P. and the R.P. with respect to the accuracy of the corresponding tooth reduction. The results were as follows. ; 1. The amount of occlusal reduction was excessive on the mesiobuccal cusp(P<0.05), and deficient on the lingual cusp in the H.P.(P<0.01). In the R.P., this was excessive on the buccal cusp and deficient on the fossa and distolingual cusp(P<0.01). 2. The amounts of marginal width were excessive in all areas except on the lingual and mesial surfaces in the H.P. and lingual surface in the R.P.(P<0.01). 3. The marginal heights were achieved more accurately in the R.P. than the H.P.(P<0.01). 4. Axial surface taper was excessive in all areas in the H.P.(P<0.01). But the axial taper of measured areas was even, and tooth is more like to retain its original axis after reduction. In the R.P., axial surface taper was excessive on the mesial and buccal area, and deficient on the distolingual area(P<0.01), and therefore, the axis of the prepared teeth was tipped in the distolingual direction. 5. The times needed for preparation were 12 minutes and 49 seconds in the H.P., and 11 minutes and 35 seconds in the R.P., and the R.P. was statistically faster(P<0.01). The tooth preparation in the H.P. achieved its goal, in that it enabled the operator to make even tooth reduction. In conclusion, the H.P. system offers an improved method that can be used in clinic after specific training.

• 대한치과교정학회지
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• 제50권1호
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• pp.52-62
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• 2020

This case report presents the orthodontic treatment of a 25-year-old patient with skeletal Class II and severe maxillary arch crowding, moderate mandibular arch crowding, anterior crossbite, and a missing lower incisor. He was treated with molar distalization using a modified C-palatal plate and temporary anchorage devices to create sufficient space for retraction. The total treatment duration was 21 months. After treatment, his occlusion and smile esthetics showed significant improvement. The modified C-palatal plate represents a treatment modality that enhances the prospects of non-extraction treatment and reduces the need for extraction.