• 대한치과기공학회지
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• 제8권1호
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• pp.91-99
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• 1986

In order to evaluate the community dental health level the actual health capacity of the lower-first permanent molar is suitable as a indicator for assessment. So we had surveyed decayed, missed and filled lower permanent first molar of 460 persons who were in the age from 20 to 29 in Iri City. The obtained results were as follows: 1. The DMFT indices of the lower first permancent molars showed in 1.40 in the age group of from 20 to 24 and 1.44 from 25 to 29. 2. The actual dental health capscities of the lower first permanent molars showed in 84.86% in the age group of from 20 to 24 and 81.03% from 25 to 29. 3. The DMF indices of the lower first permanent molars showed 15.15% in the age group of from 20 to 24 and 18.98% of from 25 to 29. 4. The DMF rates of the lower first permanent molars showed 85.66% in the age group of from 20 to 24 and 88.70% of from 25 to 29. 5. The DMF rates of the lower first permanent molars showed 70.00% in the age group of from 20 to 24 and 71.96% of from 25 to 29. 6. The DT rates of the lower first permanent molars showed 48.84% in the age group of from 20 to 24 and 39.55% of from 25 to 29. 7. The FT rates the lower first permanent molars showed 40.22% in the age group of from 20 to 24 and 43.98% of from 25 to 29. 8. The MT rates of the lower first permanent molars showed 10.94% in the age group of from 20 to 24 and 16.17% of from 25 to 29.

• 대한소아치과학회지
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• 제21권2호
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• pp.555-560
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• 1994

Among the permanent teeth. the first permanent molars play the greatest role in occlusion and function. So, the congenital missing, abnormal reuption or abnormal formation of the first permanent molars in the course of arch development would inflict normal development of dental arches. Therefore, early detection of abnormal cases related to first permanent molars and understanding of current and predictable clinical problems are essential for proper occlusal guidance in children. With the aim of investigating the clinical patterns of delayed eruption of first permanent molars in children, panoramic tomograms of the childern in mixed and early permanent dentition were observed and analyzed. The results were as follows: 1. Among the delayed eruption of first permanent molars, on tooth or bilateral teeths were affected most frequently. Delayed eruption was more prevalent in maxilla than in mandible. 2. The formation of tardily erupted teeth were also delayed. 3. Delayed eruption was generally limited in first molars or molar segments. 4. Delayed eruption of first permanent molars is accompanied by abnormal position of tooth germs, for example, ectopic eruption, delayed dental age, delayed localized tooth formation and generalized congenital missing. 5. There was a tendency of delayed formation or congenital missing of second molars distal to tardily erupted 1st molars. And that was more marked in maxilla than in mandible. 6. There was reported that affected 1st molars show various size and shapes. Maxillary 1st molars showing delayed eruption showed a tendency of having 3 cusps. But, tardily erupted mandibular 1st molars showed no significant reduction in mesiodistal dimension, as reported. 7. In some cases, the delayed eruption of 1st permanent molars was associated with ectopic eruption, but their formation was not usually retarded. 8. In skeletal class III cases, there showed a tendency of mandibular 1st molars to erupt earlier than maxillary 1st molars with greater interval than in normal occlusion.

• 대한소아치과학회지
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• 제3권1호
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• pp.7-11
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• 1976

The author measured the degree of development and the eruption pattern of first permanent molars with orthopantomography in 553 Korean children(male; 302, female; 251) from 4 to 9 years old. The orthopantomographs were obtained from dept. of pedodontics, college of dentistry, Seoul National University. The results of the studies were as follows: 1. Upper first permanent molars were erupted with distal inclination of about 30 degrees in the early stage and they gradually moved in the mesial direction by bodily movement of the tooth to be in contact with the disto-proximal surface of primary secondary molars in the late stage. 2. Lower first permanent molars were erupted with mesial inclination in the early stage and moved mesially by tipping movement of the tooth to be in contact with the disto proximal surface of the second primary molars in the late stage. 3. The eruptive forces were considered to be main etiologic factors of space closure after the premature loss of primary molars.

• 한국콘텐츠학회논문지
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• 제10권11호
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• pp.209-216
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• 2010

초등학생을 대상으로 적은 비용과 노력으로 조사할 수 있는 제일대구치 건강도를 이용하여 초등학생집단의 구강건강관리의 중요성에 대해 살펴보고 포괄적인 구강건강상태 판정에 효율적으로 활용할 수 있으며 학교구강보건사업의 정책에 기초자료로 활용하고자 2009년 3월 순천시 일개 초등학교 재학생 823명의 구강검진을 수행하였다. 건전제일대구치는 10점, 상실제일대구치나 발거지시 제일대구치는 0점, 우식증에 이환된 제일대구치의 치면의 수에 따라 1점씩 감점, 충전되어 있는 제일대구치의 치면 수에 따라 0.5점씩 감점하여 4개의 제일대구치평점을 합한 후 40점에 대한 백분율을 구하였다. 그 결과 제일대구치건강도는 36.9점, 제일대구치건강률은 92.2%이었고, 한 사람의 제일대구치건강도가 높을수록 그 사람이 보유한 우식경험영구치지수는 작아져 상관관계는 역상관(r=-0.895)이었으며, 제일대구치 우식경험치면지수도 작아져 역상관(r=-0.932)이었고, 우식경험영구치지수와의 상관관계는 순상관(r=0.902)이었다(P<0.001). 그러므로 제일대구치 건강도는 구강건강상태판정과 학교구강보건사업의 질관리를 위한 구강보건지표로 활용가능하게 여겨진다.

• 대한소아치과학회지
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• 제23권4호
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• pp.859-866
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• 1996

It is a relatively rare clinical experience to see the impacted first molar. The first permanent molar is the key in normal occlusion. Abnormal eruption of the first permanent molars would inflict normal development of dental arches and give rise to abnormal root resorption of the adjacent teeth. Therefore, the abnormally erupted first permanent molars should be detected and treated early in order to obtain proper occlusal guidance in mixed dentition period. This report presents two cases on distally tilted and impacted mandibular first molars which were treated by surgical exposure and orthodontic traction using facial mask.

• 대한치과교정학회지
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• 제46권3호
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• pp.171-179
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• 2016

Objective: The primary aim of the study was to generate new prediction equations for the estimation of maxillary and mandibular canine and premolar widths based on mandibular incisors and first permanent molar widths. Methods: A total of 2,340 calculations (768 based on the sum of mandibular incisor and first permanent molar widths, and 1,572 based on the maxillary and mandibular canine and premolar widths) were performed, and a digital stereomicroscope was used to derive the the digital models and measurements. Mesiodistal widths of maxillary and mandibular teeth were measured via scanned digital models. Results: There was a strong positive correlation between the estimation of maxillary (r = 0.85994, $r^2=0.7395$) and mandibular (r = 0.8708, $r^2=0.7582$) canine and premolar widths. The intraclass correlation coefficients were statistically significant, and the coefficients were in the strong correlation range, with an average of 0.9. Linear regression analysis was used to establish prediction equations. Prediction equations were developed to estimate maxillary arches based on $Y=15.746+0.602{\times}sum$ of mandibular incisors and mandibular first permanent molar widths (sum of mandibular incisors [SMI] + molars), $Y=18.224+0.540{\times}(SMI+molars)$, and $Y=16.186+0.586{\times}(SMI+molars)$ for both genders, and to estimate mandibular arches the parameters used were $Y=16.391+0.564{\times}(SMI+molars)$, $Y=14.444+0.609{\times}(SMI+molars)$, and $Y=19.915+0.481{\times}(SMI+molars)$. Conclusions: These formulas will be helpful for orthodontic diagnosis and clinical treatment planning during the mixed dentition stage.

• Journal of Dental Anesthesia and Pain Medicine
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• 제22권4호
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• pp.239-254
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• 2022

The high success rate of dental treatment is dependent on the cooperation of pediatric patients during procedures. Dental treatment often causes pain, particularly in children. The factors in providing treatment to pediatric patients include the characteristics and location of the tooth, profoundness of the anesthesia including the type of local anesthetic, and cooperation of the patient. Previous studies have examined several techniques to successfully achieve profound pulpal anesthesia in maxillary permanent teeth. The dentist should select the injection technique to be used based on patient needs. In children, either buccal with palatal injections or buccal with intra-septal injections may be used to anesthetize the permanent maxillary first molar. Buccal with palatal injections are commonly used prior to routine maxillary dental procedures. Currently, there are only a few studies on the employment of buccal with intra-septal injections to anesthetize permanent maxillary first molars in pediatric patients. This review will focus on efficacy of buccal with palatal versus buccal with intra-septal pulpal anesthesia of the permanent maxillary first molars in pediatric patients and aim to determine which technique should be used during routine dental procedures.

• 대한치과교정학회지
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• 제17권2호
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• pp.311-320
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• 1987

The purpose of this study was to investigate the growth changes of maxilla and mandible and position changes of first permanent molars of growing children The author analyzed the data using cephalometric roentgenogram of 43 boys and 39 girls age of 6 to 11 with normal occlusion The obtained results were as follows 1 The eruption path of maxillary and mandibular first permanent molar superimposed on TM-ANS and mandibular plane shows individual variation 2 There was no correlation between horizontal and vertical changes of maxillary first permanent molar, but positive correlation in mandibular first permanent molar 3 As the eruption, the forward changes of mandibular first permanent molar was significantly greater than that of maxillary first permanent molar 4 As the ages were increased, there were irregular growth changes of maxilla and mandible 5 Growth changes of lower anterior facial height was relatively stable 6 N-S-${\bar{6}}$ was stable after age 7.

• Journal of Oral Medicine and Pain
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• 제3권1호
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• pp.11-22
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• 1977

In order to evaluate the normal eruption time of the Korean permanennt teeth, the author had examined the eruption phases of permanent first molars in 778 males and 653 female children aged from 5 to 9-year old and analysed. The eruption was divided into 4 phases; the tip of the crown can be seen, the dull occlusal surface of the crown can be easily seen, the crown is not in contact with its antagonist, and the crown is in contact with its antagonist. The obtained results were as follows : 1. It seemed that percentage of the eruptingand erupted permanent first molar in female by age was higher than that of male. 2. In general, percentage of the erupting and erupted permanent first molar by age was higher than that of upper first molar. 3. In the correlation of age with the eruption phase, the regression equation were "y=0.43x+5.61" on male upper first molar, "y=0.41x+5.60" on male lower first molar, "y=0.44x+5.47" on female upper first molar, and "y=0.38x+5.57" on female lower first molar respectively.n female lower first molar respectively.

• 대한소아치과학회지
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• 제42권2호
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• pp.172-179
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• 2015

치근 형성은 매우 복잡한 과정이며, 유전적으로 그 형태가 정해져 있다. 유전이나 환경적인 요인이 치근발달과정에 영향을 줄 수 있다. 본 연구에서는 제1대구치의 치근형성이상을 주소로 내원한 12명의 환아들에 대하여 보고하고자 한다. 임상적으로 이들 치아는 정상적인 치관의 형태를 보이고 있었다. 그러나 방사선학적 검사상 치근이 얇고 꼬여있으며 불규칙한 길이를 나타내었다. 그리고 백악법랑경계에서 치근이개부까지의 길이는 짧았으며, 치수강은 협착되어 있었다. 이들 중 6명의 환아에서는 제2유구치의 치근형성이상이 함께 나타났으며, 3명의 환아에서는 상악 중절치의 치관형태이상이 함께 나타났다. 이들 대부분에서 조산, 뇌신경계 감염, 선천성 심질환 등의 의학적 병력이 생후 1년 이내에 관찰되었다. 제1대구치에서 특징적으로 발생하는 치근형태이상에 대한 보고는 희소하며, 본 증례에서 열두 명의 환아에서 동시에 발생한 제1대구치의 치근형성이상은 임상가들에게 새로운 증례의 발견 및 진단함에 의의가 있다.