• 대한치과기공학회지
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• 제13권1호
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• pp.21-26
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• 1991

The mesiodistal crown diameters and crown length of the permanent anterior teeth have been studied and analyzed about the mean size, S.D, S.E etcs from stone models of 100 Korean male and 74 female. From the study, the following conclusions were made : 1. Statistical differences of left and right teeth were not found in the mesio distal crown diameters and crown length of the permanent anterior teeth. 2. The mean values of mesiodistal crown diameters of permanent anterior teeth were slightly larger in male than in females and statistical differences of males and females were found in maxillary right central incisor, mandibular left canine, mandibular right lateral incisor and mandibular right canine. 3. The mean values of crown length of permanent anterior teeth were slightly larger in male than in female and statistical differences of males and females were found in mandibular left canine, mandibular right canine. 4. Mesiodistal crown diameters and crown length of maxillary left lateral incisors and right lateral incisors of female are larger than that of male.

• 대한소아치과학회지
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• 제49권4호
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• pp.468-480
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• 2022

이 연구의 목적은 구개측 및 협측 변위를 보이는 상악 영구 견치에서 차단적 유견치 발치의 효과를 평가하고, 치료 결과에 영향을 미치는 임상적 및 방사선학적 인자를 분석하는 것이다. 상악 영구 견치의 맹출 경로가 근심 및 교합면 방향을 향하면서 치관의 일부가 인접치 치근과 중첩된 것으로 진단된 환자 중 해당 부위의 상악 유견치를 발치한 86명의 환자의 97개의 상악 영구 견치를 연구 대상으로 하였다. 97개의 변위된 상악 영구 견치 중 64개(66.0%)가 유견치 발치만으로 인접 측절치 치근에서 완전히 벗어났다. 상악 영구 견치의 협-구개측 변위 방향, 치관첨의 수평 및 수직적 위치, 치근단 폐쇄 여부, 유견치의 치근단 방사선투과상 여부, 인접 측절치의 쐐기모양 여부가 치료 결과에 유의미한 영향을 미쳤다.

• 대한소아치과학회지
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• 제11권1호
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• pp.25-39
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• 1984

The author has sought to determine the time and the sequence of permanent teeth eruption in Korean children. The study group consisted of 15,671 healthy children (male 8,015 ; female 7,656) aged 5-13 years old who lived in Seoul or Cheongju. The results were as follows : 1. The eruption times of permanent teeth were 0.45 years earlier in females than in males. 2. The ages corresponding to $ER_{50}$ of permanent teeth were as follows : In Maxilla 1) central incisor was 7.37 yrs 2) lateral incisor was 8.50 yrs 3) canine was 10.83 yrs 4) 1st premolar was 10.30 yrs 5) 2nd premolar was 11.09 yrs 6) 1st molar was 6.49 yrs 7) 2nd molar was 12.79 yrs In Mandible 1) central incisor was 6.40 yrs 2) lateral incisor was 7.41 yrs 3) canine was 10.18 yrs 4) 1st premolar was 10.26 yrs 5) 2nd premolar was 11.15 yrs 6) 1st molar was 6.32 yrs 7) 2nd molar was 12.05 yrs 3. The eruption sequence of permanent teeth by Z-test was as follow: In Male 1st : Mandibular 1st molar, and Mandibular central incisor 2nd : Maxillary 1st molar 3rd : Maxillary central incisor 4th : Mandibular lateral incisor 5th : Maxillary lateral incisor 6th : Mandibular canine, Maxillary and Mandibular 1st premolar 7th : Maxillary canine 8th : Maxillary and Mandibular 2nd premolar 9th : Mandibular 2nd molar 10th : Maxillary 2nd molar In Female 1st : Mandibular 1st molar, and Mandibular central incisor 2nd : Maxillary 1st molar 3rd : Mandibular lateral incisor, Maxillary central incisor 4th : Maxillary lateral incisor 5th : Mandibular canine, Maxillary and Mandibular 1st premolar 6th : Maxillary canine 7th : Maxillary and Mandibular 2nd premolar 8th : Mandibular 2nd molar 9th : Maxillary 2nd molar 4. The corresponding permanent teeth in the mandible generally erupted earlier than the corresponding permanent teeth in the maxilla by an average of 0.73 years, but the mean eruption time of mandibular 1st premolars was almost the same as those of maxillary 1st premolars, and the mean eruption time of mandibular 2nd premolars was 0.06 years later than those of maxillary 2nd premolars. 5. There is no significant difference between left and right arch in the eruption time and sequence. 6. Generally, the ages of permanent teeth eruption tended to be earlier than those of Dr. Cha's data from 1963.

• Imaging Science in Dentistry
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• 제40권3호
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• pp.131-135
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• 2010

Purpose : The aim of this study was to investigate the timing and sequence of eruption of permanent canine and premolars, and to evaluate tooth calcification stage on emergence in Korean children. Materials and Methods : The sample was comprised of 1,266 children (male 720, female 546) aged from 7-13 years. Tooth eruption and calcification stages were determined through oral and panoramic radiographic examination, respectively. Probit analysis was used to calculate the timing of tooth eruption and tooth calcification stage from these cross-sectional data. Results : In both males and females, eruption occurred around the time when one third of tooth root or more was formed. The sequence was as follows: first premolar, canine, and second premolar in maxilla, and canine, first premolar and second premolar in mandible. Tooth eruption occurred earlier in girls compared with boys, averaging 0.63 years. Conclusions : Eruption sequence is identical in males and females with a trend for females to erupt earlier than males. Tooth eruption becomes earlier over the past decades in Korean children.

• 대한치과교정학회지
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• 제15권1호
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• pp.67-74
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• 1985

The primary objective of this study is to make the prediction percentile tabulation of the sun of mesiodistal width of the unerupted permanent canines and premolars derived from the sum of mesiodistal width of the erupted permanent mandibular incisors in Korean population. The subjects were 316 individuals with normal occlusion aged 11 to 23 years. The sum of mesiodistal width of mandibular incisors, and the sum of mesiodistal width of maxillary canine, first and second premolars, and the sum of mandibular canine, first and second premolars were measured from the dental cast models using the sliding caliper (Mitutoyo Co.). From the study, the results are as follows: 1. The sum of M-D width of mandibular incisors and the sum of M-D width of maxillary canines, first and second premolars, and the sum of M-D width of mandibular canine, first and second premolars were smaller than those of American Caucasians and Negros. 2. The correlation coefficient between the sum of M-D width of mandibular incisors and that of maxillary or mandibular canines, first and second premolars was found to be 0.598 and 0.586, respectively. 3. The regression constants were determined to evaluate the sum of M-D width of the unerupted permanent canines and premolars derived from the sum of M-D width of the erupted permanent incisors. 4. The prediction percentile tabulation were made in an attempt to predict the total M-D width of the unerupted permanent canines and premolars derived from the total M-D width of the erupted permanent mandibular incisors.

• 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.

• 치과방사선
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• 제20권1호
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• pp.79-89
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• 1990

The incidence and several characteristic features of fused and geminated teeth were studied radiographically, with full mouth periapical radiogram and pantomogram, in 4201 patients of mixed dentition and 5358 patients of permanent dentition. The obtained results were as follows: 1. The prevalence was revealed to 2.86%, 0.32%, 0.33%, and 0.06% in deciduous fused tooth, permanent fused tooth, deciduous geminated tooth and permanent geminated tooth respectively, and these anomalies were occured in female more than male. 2. Fused teeth were observed predominantly in lower anterior teeth area, especially in lateral incisor and canine region, and many cases of deciduous geminated tooth were observed in upper central incisor region. 3. Congenital missing rates of succedaneous tooth in deciduous fused teeth were 57.1 %, 85.7%, 71.0%, 69.0% in upper right and left central-lateral incisor regions, lower right and left lateral incisor-canine regions, respectively. 4. Prevalence of dental caries was 42.3%, 18.8% and 5.6% in deciduous fused, deciduous geminated and permanent fused tooth, respectively. 5. In classifying of fused and geminated teeth into 9 types, by following appearance such as number of crown, root, pulp chamber and pulp canal of those teeth, it was more favorable that Type Ⅰ(2 crown, 2 root, 2 pulp chamber, 2 pulp canal) in deciduous fused tooth and Type Ⅸ (I crown, 1 root, 1 pulp chamber, 1 pulp canal) in permanent fused tooth, deciduous and permanent geminated tooth.

• 대한소아치과학회지
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• 제42권1호
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• pp.87-101
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• 2015

하악 유견치의 조기탈락은 임상에서 흔히 관찰되는 현상으로 후에 영구치열에서 총생의 징후라 할 수 있으며 향후 영구 전치의 배열상의 문제점이나 부정교합을 유발할 수 있다. 영구 측절치가 맹출될 때 맹출 공간이 부족할 경우 인접해 있는 유견치 치근을 흡수시키면서 맹출하게 되고 그 결과 유견치가 조기에 탈락하게 되는데, 이 경우 영구 하악 영구 절치들이 설측으로 경사지게 되면 상악 절치들과 교합 접촉이 상실되어 상악 절치들이 과맹출됨으로써 수직피개교합 및 수평피개교합이 깊어지며 악궁둘레길이는 감소된다. 유견치가 편측으로 상실된 경우는 상기 현상 이외에, 영구 절치들이 조기 상실된 부위의 공간으로 경사지게 되어 정중선이 틀어지게 된다. 보통 4 mm 이하의 공간부족은 순차적인 유치의 disking과 passive lingual arch를 사용하여 leeway space를 보호하는 것만으로도 해결이 가능하며 4~6 mm 공간부족은 상기 술식과 함께 악궁의 전후방 및 측방확장으로 어느정도 해소할 수 있다.

• 대한소아치과학회지
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• 제35권2호
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• pp.339-344
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• 2008

상악 영구 견치의 매복에 비해 하악 영구 견치의 매복은 매우 드물게 일어난다. 치아가 매복된 경우 장애물 존재 여부와 매복 위치와 방향, 맹출 가능한 공간의 유무, 치근의 형성 단계 등의 요소에 따라 매복 치아의 발거 혹은 장애물의 제거 후 주기적 관찰, 맹출이 지연된 치아의 외과적 노출, 교정적 견인 등의 방법으로 치료하게 된다. 본 증례는 하악골의 골절 부위에 시행된 골간 강선 결찰과 미니 플레이트에 의해 하악 좌측 견치가 매복되어 있었던 경우로 CT 검사 결과 하악 정중부위 플레이트의 스크류가 맹출을 방해하고 있는 것으로 판단되어 전신 마취 하에 플레이트를 제거하였다. 이후 자연적인 맹출을 기대하였으나, 맹출력이 부족하여 교정적 견인으로 양호한 결과를 얻었기에 보고하는 바이다.

• 대한치과의사협회지
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• 제50권6호
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• pp.312-321
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• 2012

Permanent canine are very important teeth in point of function as well as esthetic. Therefore impaction of canines is a frequently encountered clinical problems. The incidence of impaction ranges between 1-3%. The cause of canine impaction can be result of ectopic position of tooth germ, defect of dental follicle, early loss or delayed exfoliation primary canine, space problem, supernumarary teeth, cyst, odontoma, Impaction frequently involves further complication such as root resorption of adjacent teeth, cyst formation and migration of the neighboring teeth. Various treatment modalities include extraction of primary canine, surgical opening and orthodontic traction, autotransplantation, surgical extraction of impacted canine.