• 대한치과교정학회지
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• 제12권2호
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• pp.145-154
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• 1982

Plaster models were constructed and orthopantomographs were taken for 86 male and 70 female primary school pupils, whose upper and lower permanent 4 incisors and 1st molars were completely erupted without crowding; whose deciduous canines and molars were found almost uniformly even without any visible tooth fractures, dental caries or restorations on proximal surfaces of the teeth. Certain reference points on the orthophantomograph were set up and measured and the values were compared with actual or predicted values from the models. The following results were obtained: 1. In regards to available space, the values from the orthopantomograph were greater than the values from the models by a mean of 3.24% on the upper and 10.06% on the lower for males; 3.05% on the upper and 10.01% on the lower for females. 2. In regards to total mesiodistal widths of permanent canine, 1st and 2nd premolars, the values from the orthopantomograph were greater than the presumed values based on the size of lower permanent 4 incisors from the models by a mean of 18.50% on the upper and 24.09% on the lower for males; 14.54 on the upper and 20.51% on the lower for females. 3. Comparing the magnified values of total mesiodistal widths of permanent canine, 1st and 2nd premolars with those of available space, the regression constants of regression equation (Y = a + bX) between them were a=3.2336, b=0.6533 on the upper and a=5.0138, b=0.3290 on the lower for males; a=2.5994, b=0.6521 on the upper and a=3.0113, b=0.6586 on the lower for females. 4. The correlation coefficients between the magnified values of available space and permanent canine, 1st and 2nd premolars were moderately positive as 0.6474 in the upper and 0.505 on the lower for males; 0.6493 on the upper and 0.6183 on the lower for females. 5. In regards to magnified values of the available space from the orthopantomographs there were no significant difference between sexes, (P>0.05) but of the total mesiodistal widths of permanent canine, 1st and 2nd premolars, a significant difference between sexes was found.(p<0.01).

• 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.

• 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.

• 대한치과교정학회지
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• 제15권2호
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• pp.341-352
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• 1985

The primary objective of this study is to estimate of the mesiodistal crown diameters of the unerupted permanent successors derived from the mesiodistal crown diameters of the deciduous teeth in Korean population. The subjects were 54 individuals (twenty nine boys and twenty five girls) with normal occlusion aged 6 to 13 years. The mesiodistal crown diameters of the deciduous and the successional permanent teeth were measured from the longitudinal dental cast models using the sliding calipers (Mitutoyo Co.). From the study, the results are as follows; 1. Sex differences of mesiodistal won diameters were less in the deciduous teeth, but male were more than that of female in the successional permanent teeth. 2. The mesiodistal crown diameters of the deciduous central incisors, lateral incisors, canines were smaller than that of the successional permanent teeth and the deciduous 1st molars, and 2nd molars were more larger than that of the successional permanent teeth. 3. Size differences between sum of the mesiodistal crown diameters of central incisors and lateral incisors in the decidous teeth and the successional permanent teeth were $7.20{\pm}1.79mm$ in upper, $5.38{\pm}1.64mm$ in lower and that of canine,1st molar and 2nd molar in the deciduous teeth and the successional permanent teeth were $0.56{\pm}1.19mm$ in upper, $2.22{\pm}1.19mm$ in lower. 4. In male, the correlation coefficients between the upper deciduous central incisor and the successional permanent tooth (r = 0.57) and in female, the correlation coefficients between the upper deciduous 1st molar and the successional permanent tooth (r=0.67) appeared the highest. 5. The regression constants were determined to estimate the mesiodistal crown diameters of the unerupted successional permanent teeth.

• 대한소아치과학회지
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• 제34권3호
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• pp.430-437
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• 2007

현재 혼합치열 분석 방법으로 가장 널리 사용되고 있는 Moyers의 예측표나 Tanaka와 Johnston의 예측방정식은 북유럽 인종의 백인 자료를 바탕으로 만들어졌기 때문에 한국인에게 적용하기에는 무리가 있다. 또한 최근에는 이들이 제시한 하악 전치에 기초한 방법이 미맹출 견치와 소구치 폭경의 합을 예측하기 위한 최적의 예측인자인지에 대해서도 의문이 제기되고 있다. 본 연구의 목적은 한국인 집단을 대상으로 미맹출 견치와 소구치의 근원심 폭경을 예측하기 위한 최적의 예측인자가 어떤 치아의 조합인지 밝히고, 그 조합을 이용한 예측 방정식을 제시하며, 새로운 예측 방정식의 임상 적용을 위해 그 타당성을 검증하는 것이다. 완전한 영구치열을 가진 성인 178명(남자 108명, 여자 70명, 평균 나이 21.63세)의 자료를 기초로 예측방정식을 도출하였으며, 53명의 청소년(남자 25명, 여자 28명, 평균 나이 14.22세)으로 검증집단을 구성하여 그 타당성을 검증하였다. 그 결과 다음과 같은 결론을 얻었다. 1. 한국인 혼합치열기 청소년에서 미맹출 견치와 소구치 폭경의 합을 예측하기 위한 최적의 치아 조합은 상악 중절치, 하악 측절치, 상악 제1대구치 폭경의 합이었다($r=0.65{\sim}0.80$). 2. 상악 중절치, 하악 측절치, 상악 제1대구치 폭경의 합을 기초로 하고 부가적인 설명 변수로 성별과 악궁을 포함시켜 계산한 예측 방정식은 다음과 같이 계산되었다. 남자, 상악: $Y\;=\;0.332{\times}X_0\;+\;6.195$ 남자, 하악: $Y\;=\;0.332{\times}X_0\;+\;5.269$ 여자, 상악: $Y\;=\;0.332{\times}X_0\;+\;5.929$ 여자, 하악: $Y\;=\;0.332{\times}X_0\;+\;5.003$ 예측 방정식의 설명력은 64%였으며 표준오차(SEE)는 0.71mm였다. 3. 새로운 예측 방정식을 검증 집단에 적용하여 검증한 결과, 약 97%에서 실제 측정한 견치와 소구치 폭경의 합과 예측치와의 차이가 1mm 이하였다.

• 대한소아치과학회지
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• 제23권4호
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• pp.788-799
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• 1996

The purpose of this study was to determine the accuracy of the prediction methods which are frequently used in the clinic, such as Moyers', Tanaka and Johnston's, Song's Hixon and Oldfather's, Kaplan's, Smith's. These prediction methods were compared to the data, which were obtained from 100 Kyung-Hee University students (50 males and 50 females) with normal occlusion of permanent dentition, using a retrospective statistical analysis. The standard periapical radiopgraphs for the lower premolars using 16-inch long cone technique and the yellow stone dental casts were taken from each samples. The mesiodistal widths of 4 incisors, canine, premolars were measured on the dental casts, and those of premolars were measured on the radiographs. The correlation coefficients, paired samples t-tests, regression coefficients between the actual measuredments of the samples and the predicted measurements of each methods were analyzed. The results obtained were as follows: 1. The prediction methods using periapical radiographs tended to show a stronger correlation than the methods using dental casts; the correlation coefficients between the actual widths of the lower canine and premolars and the predicted widths of the tested methods were higher in Smith, Kaplan, Hixon & Oldfater, and Tanaka & Johnston (p<0.001). 2. The Moyers' probability chart at 65 % showed a tendency toward the least difference between the actual measurements and the predicted widths of the lower canine and the premolars, and the methods of Smith, Kaplan, Tanaka & Johnston also showed a less difference. 3. By means of evaluation in correlation coefficients and paired smaples t-tests, the Smith and Tanaka & Johnston in male, and the Moyers' 65 % and Song in female showed a high tendency toward accurate methods. 4. The regression equations by models that are derived from the study were as follows: Male(Lt.) :Y=10.799+0.475X Femle(Lt.) :Y= 7.427+0.609X (Rt.) :Y=11.043+0.462X (Rt.) :Y= 8.475+0.556X 5. The regression equations by radiographs that are dericed from the study were as follows: Male(Lt.) :Y=6.5651+0.9720X Femle(Lt.) :Y=4.8656+1.0632X (Rt.) :Y=7.8610+0.9060X (Rt.) :Y=4.5483+1.0843X

• Journal of Korean Dental Science
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• 제3권1호
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• pp.17-24
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• 2010

Objective : To investigate the prevalence of dental anomalies and to determine the associations between dental anomalies in permanent teeth Materials and methods : The samples were 1,240 patients (760 females and 480 males, mean age=15.1 years) who visited the Samsung Medical Center. Dental anomalies were diagnosed using pre-treatment dental casts, radiographs, clinical examinations, and medical/dental histories. Prevalence and association were investigated according to gender and sidedness. The Chi-square test was performed for statistical analysis. Results : The most common missing tooth was the lower lateral incisor, followed by the lower and upper second premolars. This particular dental anomaly is characteristic of the East Asian population (prevalence of congenital missing tooth=12.3%). The upper anterior area was the most frequently affected area (prevalence of supernumerary tooth was 1.5%). The presence of a supernumerary tooth was more prevalent in males than in females (p<.05, odds ratio=3.2). The most frequently affected tooth was the upper canine (prevalence of impacted tooth=4.3%). Unilateral impaction of the upper canine occurred significantly more often compared to bilateral impaction (p<.001). The prevalence of peg lateralis was 2.7%. The presence of congenital missing tooth was closely associated with peg lateralis (p<.01). If children aged 7~8 years have peg lateralis, the rest of the teeth should be checked for congenital absences. Conclusion : The early detection of dental anomalies and understanding of their associations help clinicians determine the appropriate treatment timing and methods of dealing with these anomalies.

• 대한소아치과학회지
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• 제43권1호
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• pp.1-7
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• 2016

이 연구의 목적은 Nolla 방법에 근거하여 소아 청소년에서 나이와 성별에 따른 영구치의 평균 발육 연령을 평가하기 위한 것이다. 연세대학교 치과대학병원에 내원하여 파노라마 사진을 촬영한 어린이 중 4세에서 15세의 남녀 각각 50명을 대상으로 하여 1,200명의 파노라마 사진을 후향적으로 조사하였다. 3명의 잘 훈련된 조사자가 Nolla 방법에 의하여 상, 하악 영구치의 발육 단계를 평가하였다. 조사자 간 신뢰도(ICC, intra-class correlation coefficient value)는 0.973으로 높은 일치도를 보였다. 조사 결과를 바탕으로 발육 연령의 평균값을 계산하였다. 치관이 완성되는 Nolla 6단계는 남아에서는 상악 중절치부터 제2대구치까지 각각 5.4, 6.4, 6.7, 7.5, 7.8, 4.6, 8.1세에서 나타났고, 하악에서는 4.8, 5.1, 6.0, 6.5, 7.2, 4.5, 8.0세에서 나타났다. 여아에서는 상악에서 5.3, 6.0, 6.3, 7.3, 7.7, 4.8, 8.1세, 하악에서는 4.8, 5.1, 5.9, 6.5, 7.2, 5.0, 7.9세에 치관이 완성되었다. 본 연구를 통하여 우리나라 소아 청소년 환자에서의 영구치의 평균 발육 연령을 평가하였다. 성장 중인 환자의 진단과 치료 계획 수립에 있어 본 연구의 결과가 임상적으로 유용하게 적용될 수 있을 것으로 생각된다.

• 대한치과교정학회지
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• 제52권6호
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• pp.432-438
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• 2022

Objective: To compare crown-root angulations of the permanent maxillary anterior teeth in skeletal Class I, Class II, and Class III Korean malocclusion patients using cone-bean computed tomography (CBCT) images. Methods: Sixty CBCT images were collected from orthodontic patients archive based on skeletal Class I (0˚< A point-nasion-B point angle [ANB] < 4˚), Class II (ANB ≥ 4˚), and Class III (ANB ≤ 0˚) to have 20 samples in each group. Mesiodistal crown-root angulation (MDCRA) and labiolingual crown-root angulation (LLCRA) were evaluated after orientation of images. Crown-root angulations were compared among Class I, Class II, and Class III groups and among the maxillary anterior teeth in each group. Results: LLCRAs of the maxillary central incisor and the lateral incisor were significantly lower in Class III group than those in Class I group. However, those of the canine showed no significant differences among groups. MDCRAs of the maxillary anterior teeth did not significantly differ among groups either. Conclusions: Our results suggest that skeletal Class III malocclusion might affect LLCRA of the maxillary incisors, especially the central incisor.

• 대한치과교정학회지
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• 제52권6호
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• pp.451-460
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• 2022

Moebius syndrome (MBS) is a congenital neurologic disorder that causes cranio-facial abnormalities. It involves paralysis of the VI and VII cranial nerves and causes bilateral or unilateral facial paralysis, eye movement disorder, and deformation of the upper and lower limbs. The orofacial dysfunctions include microstomia, micrognathia, hypotonic mimetic and lip muscles, dental enamel hypoplasia, tongue deformity, open bite or deep overbite, maxillary hypoplasia, high arched palate, mandibular hyperplasia or features indicating mandibular hypoplasia. This case report presents a 7-year-old male patient who was diagnosed with MBS at the age 2 years. The patient displayed typical clinical symptoms and was diagnosed with Class II malocclusion with a large overjet/overbite, tongue deformity and motion limitation, and lip closure incompetency. Treatment was initiated using a removable appliance for left scissor bite correction. After permanent tooth eruption, fixed appliance treatment was performed for correction of the arch width discrepancy and deep overbite. A self-ligation system and wide-width arch form wire were used during the treatment to expand the arch width. After 30 months of phase II treatment, the alignment of the dental arch and stable molar occlusion was achieved. Function and occlusion remained stable with a Class I canine and molar relationship, and a normal overjet/overbite was maintained after 9.4 years of retainer use. In MBS patients, it is important to achieve an accurate early diagnosis, and implement a multidisciplinary treatment approach and long-term retention and follow-up.