• 대한소아치과학회지
• /
• 제26권1호
• /
• pp.1-13
• /
• 1999

To study the caries patterns in primary dentition, 719 preschool children, 4-6 years old, were examined for their caries activity(salivary reductase activity) and caries experience of individual teeth. Teeth groups were made by cluster analysis using dft indexes of individual teeth as criteria. The six major teeth groups in the order of dft index from high to low were (1) lower primary molars, (2) upper primary molars, (3) upper central incisor, (4) upper lateral incisor, (5) canines, and (6) lower incisors. There were significant differences in dft index between teeth groups except upper lateral incisor and canines. Upper and lower primary molars showed the highest correlation in dft index, and the next couples were upper central incisors and upper lateral incisors, upper lateral incisor and canines, upper central incisor and canines, upper lateral incisor and upper primary molars, and canines and upper primary molars in descending order. Upper first primary molar showed the greatest differences in dft index between caries activity levels.

• 대한소아치과학회지
• /
• 제7권1호
• /
• pp.21-32
• /
• 1980

The purpose of this study is to determine the developmental relationship between the maxillary primary central incisors and their permanent successor. The auther took 315 cases of lateral cephalogram of the children (males were 171, females were 141) Angular change of the teeth and horizontal and vertical linear change were observed. The obtained results were as follows: 1. The inclination of the long axes of both incisor teeth was relatively stable and labio-version of both incisore was significant at 7 years of age. 2. The distance between the incisal edge of the permanent central insisor and the resorbing apex of the primary maxillary central incisor remained within 2mm of each other, 3. Vertical growth of the maxillary anterior portion was greater than horizontal growth from 6 to 7 years of age. 4. There was not a significant sexual difference.

• 대한소아치과학회지
• /
• 제36권3호
• /
• pp.387-393
• /
• 2009

본 연구는 상악 유전치부의 치간공간과 인접면 우식의 상관관계를 평가해보고자 하였다. 익산에 거주하는 만3-7세의 어린이 555명을 대상으로 하였으며 탐침이 통과하는지 여부로 치간공간이 있음과 없음으로 분류하였고 와동이 형성되었거나 법랑질 표면이 연화되었을 경우 인접면 우식이 존재하는 것으로 판단하였다. 연구 결과 다음과 같은 결론을 얻었다. 1. 상악 유전치부의 치간공간은 영장류 공간이 77.4%, 발육공간이 유측절치와 유중절치 사이에서 54.4%, 양유중절치 사이에서 39.0%로 나타났다. 2. 인접면 우식발생율은 우측유견치가 6.3%, 우측유측절치가 14.7%, 우측유중절치가 33.5%, 좌측유중절치가 33.7%, 좌측유측절치가 16.0%, 좌측유견치가 4.7%로 나타났다. 3. 치간공간의 수가 많을수록 상악 유전치의 우식발생율은 낮아졌으나 그 상관관계(r=-0.024)는 미약하였다. 4. 상악 유전치부에 공간이 존재하지 않을 경우 존재할 때 보다 평균 우식발생율이 높았으며, 치간공간이 전혀 존재하지 않는 경우 한 곳이라도 치간공간이 존재하는 경우보다 평균 우식발생율이 2배 이상 높은 것으로 나타났다.

• 대한소아치과학회지
• /
• 제11권1호
• /
• pp.145-150
• /
• 1984

Author have measured the depth of gingival sulcus of the primary teeth. 333 teeth were selected from the children who attended on the department of pedodontic, College of dentistry, Yonsei University, and kindergarten children at Won Ju city aged from 1 year 8 months to 10 year 2 months. 1998 point were measured. The results were as follows. ; 1. Facial surface was the shallowest in sulcus depth compared with other surfaces. It was 1.56 mm. The depth of sulcus in lingual surface was deeper than facial. 2. The deepest part of each surface was mesial and distal, There were no statistical differences between mesial and distal part of the sulcus depth. 3. The mean sulcus depth of each tooth was as follows. Primary central incisor.....1.71mm. Primary canine....1.75mm. Primary second molar.....2.03mm. 4. The mean sulcus depth of upper was 1.86mm, and the lower was 1.76mg. The upper tooth was deeper than lower in sulcus depth. 5. The lower primary central incisor had the shallowest sulcus and the upper 2nd primary molar had the deepest compared with other tooth. 6. There wasn't specific statistical differences between the age groups of primary dentition and mixed dentition.

• 대한소아치과학회지
• /
• 제25권2호
• /
• pp.383-399
• /
• 1998

Tooth development is usually described in four stages such as bud stage, cap stage, bell stage and crown stage. Exact time of appearance of tooth primordia is different among reports, and up to now there is no timetable regarding initial tooth development. To understand the congenital malformations and other disorders of the orofacial region, there is a need to establish a standard timetable on early tooth development. Till now, studies on the tooth development were mainly on later fetuses, and only few reports on early stage. Also, there were no reports on the time when bud stage turns to cap stage, and cap stage to bell stage. In this study, external morphology of face and the early development of the tooth, and transition of bud stage to cap stage, cap stage to bell stage were studied using 27 staged human embryos and 9 serially sectioned human fetuses. The results are as follows: 1. Mandibular region was formed by union of both mandibular arch at stage 15, and maxillary region by union of maxillary arch, medial nasal prominence, and intermaxillary segment at stage 19. 2. Ectodermal thickening which represents the primordia of tooth appeared in mandibular region at stage 13, and maxillary region at stage 15. 3. Bud stage began from mandibular primary central incisor at stage 17, and maxillary primary central incisor at stage 18. And the sequence of appearance was in the mandibular primary lateral incisor at stage 19, maxillary primary lateral incisor at stage 20, mandibular primary canine at stage 22, maxillary primary canine and primary first molar at stage 23, madibular primary first molar and maxillary primary second molar at 9th week, and mandibular primary second molar at 10th week of development. 4. Cap stage began from the primary anterior teeth at 9th week, and primary second molar still had the characteristics of cap stage at 12th week of development. 5. Transition to bell stage started from the primary anterior teeth at 12th week, and primary second molar started at 16th week of development. 6. Trnasition to crown stage started from primary anterior teeth at 16th week, and primary second molar at 26th week of development.

• 대한소아치과학회지
• /
• 제48권3호
• /
• pp.352-358
• /
• 2021

Molar-incisor malformation (MIM)은 치관은 정상이나 치근의 비정상적인 형태를 보이는 것이 특징적이다. 제1대구치에 가장 많이 발생하며, 제2유구치나 상악 중절치도 때때로 이환된다. 이 증례 보고에서는 제1대구치를 포함해, 제2유구치에 MIM이 나타난 환자의 증례를 보고하고, 치근이 건전하게 발거된 제2유구치의 micro computed tomography (CT)를 이용한 형태학적 분석을 시행하였다. 발거된 치아에서는 MIM의 외형적 특징인 치관 - 치근 이행부의 cervical constriction을 육안상으로 확인할 수 있었으며, micro CT 분석에서 백악법랑경계부의 광화된 부위 (Cervical Minelarized Diaphragm), 많은 부근관과 막힌 근관 등의 복잡한 근관 형태, 근관 내 석회화 물질, 영구치에 비해 상대적으로 협착된 치관부 치수강이 관찰되었다.

• 대한치과교정학회지
• /
• 제50권3호
• /
• pp.216-226
• /
• 2020

Root resorption can be caused by several factors, including contact with the cortical bone. Here we report a case involving a 21-year-old female with Angle Class II, division 1 malocclusion who exhibited significant root resorption in the maxillary right central incisor after orthodontic treatment. The patient presented with significant left-sided deviation of the maxillary incisors due to lingual dislocation of the left lateral incisor and a Class II molar relationship. Cephalometric analysis demonstrated a Class I skeletal relationship (A point-nasion-B point, 2.5°) and proclined maxillary anterior teeth (upper incisor to sella-nasion plane angle, 113.4°). The primary treatment objectives were the achievement of stable occlusion with midline agreement between the maxillary and mandibular dentitions and appropriate maxillary anterior tooth axes and molar relationship. A panoramic radiograph obtained after active treatment showed significant root resorption in the maxillary right central incisor; therefore, we performed cone-beam computed tomography, which confirmed root resorption along the cortical bone around the incisive canal. The findings from this case, where different degrees of root resorption were observed despite comparable degrees of orthodontic movement in the bilateral maxillary central incisors, suggest that the incisive canal could be an inducing factor for root resorption. However, further investigation is necessary to confirm this assumption.

• 대한소아치과학회지
• /
• 제31권3호
• /
• pp.406-411
• /
• 2004

영구 상악 절치의 매복은 매복이 흔한 제3대구치와 상악 견치에 비해서 드물지만 상악 중절치 미맹출을 주소로 내원한 학동기 아동에서 종종 관찰된다. 매복을 유발시키는 원인에 대해서는 많은 논란이 있으나 주 요인으로는 유치의 외상과 유치의 치근단 감염이 보고되고 있다. 특히 유치의 치근단 감염에 의한 매복설이 유력한데 병소의 압력에 의한 계승영구치의 회전, 변위등의 위치변화가 일어날 수 있다고 보고되고 있다. 매복치는 무엇보다도 조기에 발견하여 치료하는 것이 이로 인해 발생되는 부정교합이나 그 밖의 부작용을 예방할 수 있다. 일단 매복이 진단되면 방사선 검사를 통하여 위치 확인을 정확히 하는 것이 중요하며 치료에 앞서 전반적인 공간분석과 치료계획을 세워야 한다. 치료로는 교정적 견인, 또는 자가이식등이 있으며, 역위 매복된 경우가 아니라면 공간 확보만으로도 50%의 자발적 맹출을 보고하고 있다. 본 증례는 유치의 치근단 감염에 의해 역위 매복된 것으로 보이는 상악 중절치를 교정력을 이용해 정상적인 맹출로 바로 잡아준 결과 4-5개월만에 자발적으로 맹출하였기에 이에 보고하는 바이다.

• 대한소아치과학회지
• /
• 제32권3호
• /
• pp.550-556
• /
• 2005

매복치아란 어떤 원인에 의하여 구강점막이나 악골내에서 치아의 맹출이 중지된 상태를 말하며, 악궁내의 어떠한 치아도 매복될 수 있으나 가장 흔하게 이환되는 치아는 상, 하악 제 3대구치, 상악 견치, 상, 하악 제 2소구치, 상악 중절치의 순으로 나타난다. 이 중 상악 영구 전치의 매복률은 0.1-0.5% 정도이며 매복 원인으로는 여러 가지가 있으나 유전치의 외상, 과잉치, 치근단 병소로 인한 매복이 흔하며 조기에 적절히 치료되지 못하면 정중선의 변위, 인접치에 의한 맹출공간 감소, 치조골 높이의 차이 등의 결과를 유발한다. 치료로는 주기적 관찰방법, 매복치의 맹출로가 정상이며 치근이 미완성일 경우 상부 연조직과 경조직을 단순히 제거하여 맹출을 유도하거나 외과적 노출 후 매복치를 교정하는 방법, 치아이식술, 발치 등을 시행할 수 있다. 본 증례들은 상악 중절치의 맹출 지연을 주소로 본원에 내원한 환아들로 상악 중절치의 변위 매복을 외과적 노출과 교정적 견인을 시행하여 양호한 결과를 얻어 보고하는 바이다.

• 대한소아치과학회지
• /
• 제25권4호
• /
• pp.717-730
• /
• 1998

The Finite Element Analysis has been used for stress analysis of prosthesis, orthodontic or orthopedic appliances and filling materials. The primary purpose of the present studying was to evaluate the effectiveness of needle post in promoting the retention and integrity of composite crown restored on the pulpotomized primary central incisor. Three finite element models-natural tooth (Sample I), composite crown with (Sample II) and without (Sample III) needle post-were constructed and the stress distribution within each model were analyzed and compared one another. The results can be summarized as follows: 1. In sample I, the stress was shown to have distributed uniformly throughout the whole tooth even to the alveolar bone. 2. In sample II, the transmission of stress from the crown to the root area was shown to be very poor and irregular. 3. In sample III, the needle post was proved to be very effective in distributing the stress well to the aveolar bone which might help in maintaining the stability of crown restoration.