• 대한치과보철학회지
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• 제37권2호
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• pp.242-255
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• 1999

The purpose of this study was to estimate the morphology and the size of permanent mandibular molar in Korean Adult. The 100 dental college students with a normal dentition and without any dental prosthesis and severe caries were selected for this study The subjects were taken impression to make study model. On the study model, the 5 dentists measured those sizes and estimated morphological structures with a calipers, a Boley gauge and a protractor. The results were as follows; 1. The clinical crown height, width, thickness and the other anatomical structures had symmetrical relationship between the left and right mandibular molar. 2. In the clinical crown height aspect, the buccal crown heights always were higher than the lingual crown height. The heights of the each surface, the buccal or lingual surface, were gradually decreased from the 1st molar to the 2nd molar and the difference on the buccal surface was higher than that on the lingual surface. 3. In the clinical crown width aspect, the mesiodistal measurement of the mandibular 1st molar was higher than that of the mandibular 2st molar. 4. In the clinical crown thickness aspect, the mesial buccolingual measurement was highest on the mandibular 1st molar and the distal buccolingual distance was lowest on the mandibular 2nd molar. This distal thickness of the mandibular molar always was higher than that of the mesial half. 5. The well-developed mesiobuccal groove of the 1st molar was observed more often than that of the 2nd molar. The buccal pit was also observed more frequently at the 1st molar, but the frequency(35%) was not high. 6. The occlusal type according to the number of cusp was almost 5-cusp(98%) in the 1st molar and was also 5-cusp(63%) in the 2nd molar. The frequency of the 6th cusp was 31% in the 1st molar and was 22% in the 2nd molar. The frequency of the 7th cusp was below 2of in the both teeth. 7. In the buccolingual intercuspal distance aspect of the mesial and distal half, the intercuspal distance of distal half was higher than that of the mesial half on the 1st and 2nd molar, but the difference on the 1st molar was higher than that on the 2nd molar. 8. The difference between the widths of the buccal and lingual half was 1.5mm in the 1st molar and 0.8mm in the 2nd molar. Therefore the lingual convergency of the occlusal surface was more higher in the 1st molar. 9. On the mandibular 1st and 2nd molar, the distobuccal external angle was more acute than the mesiobuccal external angle. But the mesiobuccal internal angle was more acute than the distobuccal internal angle. 10. When the mandibular molar was a 5-cusp type, the development of the distal cusp on the 1st molar was better than that on the 2nd molar. The difference between the cusps was around 0.4mm.

• 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.

• 대한치과의사협회지
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• 제21권12호통권175호
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• pp.1005-1010
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• 1983

To study the eruption process of the permanent tooth, esp., 1st molar, the author took 303 cases of oblique cephalogram (Male. 162 cases, Female: 141 cases) from age 3 to 8 yea old children, and observed the vertical change and axial change. The result were as follow: 1. The mesial end of upper 1st molar was closer to the occlusal plane than the distal, and they were erupting toward the occlusal plane by aging. In the case of lower 1st molar, the distal end was closer to the occlusal plane than the mesial and the occlusion showed the tendency to accord with the plane to be settled by aging. 2. Eruption rate of the upper and lower 1st permanent molar increased rapidly at 5 or 6 years of age. 3. Axial inclination of lower 1st permanent molar to the mandibular plane decreased gradually from 3 years of age, except for 6 years of age. There was some increase at 5 or 6 years of age.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권6호
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• pp.432-439
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• 2012

Purpose: The aim of this study was to investigate the blood supply to the maxillary sinus in Koreans using computed tomography of the lateral wall of the sinus, and to analyze the data according to demographic data, and to compare our results with previously published research. Methods: One hundred and three patients (males 51, females 52) who visited the dental clinic were evaluated. We investigated the canals with cone-beam computed tomography, and measured the diameter and length from the bony notch of the vascular canal at the lateral wall of the sinus to each of the reference planes. Results: Most types of vascular canal were type I & II (total 72.2%) which were driving through inside the sinus wall. Type IV, V were frequently investigated in 1st premolar and 2nd molar. Mean height; from anterior nasal spine-posterior nasal spine plane to vascular canal was 5.56 mm in 1st premolar, 2.11 mm in 2nd premolar, 0.98 mm in 1st molar, 4.32 mm in 2nd molar; from the basal layer of the sinus was 4.93 mm in 1st premolar, 5.00 mm in 2nd premolar, 6.05 mm in 1st molar, 7.91 mm in 2nd molar; and from alveolar crest, 20.80 mm in 1st premolar, 16.57 mm in 2nd premolar, 14.01 mm in 1st molar, 16.17 mm in 2nd molar. The mean height of the vascular canal of each reference plane showed no significant difference between sex, site (left or right) and age. The mean diameters of the canals were 1.76 mm in male, and 1.50 mm in female. Diameter decreased with age, and tooth site (from 1st premolar to 2nd molar). Conclusion: These results show that the mean diameter of the vascular canal of the maxillary sinus varies according to age, sex, and tooth site, but that the mean height of canal had no significant difference based on these three factors.

• 대한치과보철학회지
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• 제52권4호
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• pp.324-330
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• 2014

임플란트와 자연치를 연결하여 보철물을 제작할 경우, 자연치에 함입현상이 일어날수 있음은 여러 보고로 알려져 있다. 이를 설명하는 메커니즘은 여러가지가 있으며, 이에 임플란트와 자연치를 연결 하는 보철물 형태는 권장되지 않는다. 본 증례는 임플란트와 인접 하지만, 연결되어 있지는 않은 자연치가 인접면 접촉과 연관되어 함입이 일어난 증례이다. 68세 여성이 상악 좌측 제2소구치 및 제2대구치 발치후, 임플란트 수술 및 보철수복을 받았으며, 임플란트 사이의 제1대구치는 크라운 치료를 받았다. 2.5년 후, 제2대구치 근심면의 접촉이 느슨해져 상기 보철물의 근심면 합착을 시행하였다. 그로부터 7개월후, 제1대구치의 약 2 mm 함입이 발생하였으며, 치주문제로 인한 통증도 발생하였다. 제1대구치의 크라운을 제거하고 다시 정출이 일어났고, 치주 통증도 사라졌다. 이에 본 증례를 분석, 보고하는 바이다.

• 치위생과학회지
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• 제9권3호
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• pp.257-263
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• 2009

본 연구의 목적은 신체 발육발달의 기준이 되는 나이 그리고 키와 몸무게의 요인들 중 제 1대구치 맹출정도에 더 많이 관련되는 요인이 무엇인지를 탐색하고, 각각의 요인의 상관계수를 파악하고자 하는 연구로서 우리나라 충남 아산, 서산에 거주하는 만6세 아동 441명을 대상으로 만들어진 자료를 이용하여 얻어진 단면 연구이다. 연구의 결과는 제1대구치 맹출정도와 월령의 관련성에서 통계적으로 ($x^2$(df) = 117.68로 p < 0.001 수준에서 유의한 차이가 있었다. 즉, 제1대구치 맹출정도 점수가 높을수록 월령수가 높음을 알 수 있다. 제1대구치 맹출정도와 키(신장)와의 관련성에 대한 결과로는 ($x^2$(df) = 59.74 p < 0.001 수준에서 유의한 차이가 있었다. 즉, 제1대구치 맹출정도 점수가 높을수록 키가 크다는 것을 알 수 있었다. 제1대구치 맹출정도와 몸무게(체중)과의 관련성에 대한 결과는 ($x^2$(df) = 31.69 p < 0.001 수준에서 유의한 차이가 있음을 알 수 있었다. 즉, 제1대구치 맹출정도 점수가 높을수록 몸무게가 많이 나가는 것을 알 수 있었다. 제1대구치 맹출정도와 월령, 키, 몸무게의 각 변수들간의 상호 관련성은 모두 p<0.001 수준에서 유의한 상관을 나타내고 있었으며 제1대구치 맹출정도와 월령 간에 정적인 상관(r=.45, p < 0.01), 맹출정도와 키 간에 정적인 상관 (r=.31, p<0.01). 맹출정도와 몸무게 간의 정적인 상관 (r=.24, p<0.01), 또한, 월령과 키 사이에 정적인 상관 (r=.40, p < 0.01), 월령과 몸무게 사이에 정적인 상관 (r=.24, p < 0.01), 키와 몸무게 사이에서도 정적인 상관 (r=.54, p<0.01) 관계를 보이고 있으며 각각의 항목에서 유의한 상관관계를 나타내고 있었다. 만 6세 아동의 제1대구치 맹출정도와의 관련성은 월령, 키, 몸무게 순이었으며 이에 대한 설명력은 29.1% 이었다. 이상의 결과에서 각각의 변수들은 인과관계가 아니며 종속연수가 하나 이상의 독립변수에 의하여 영향을 받는다는 것을 알 수 있었으며 제1대구치 맹출 정도와 월령, 키와 몸무게는 이들 항목 간 상호 복합적으로 작용하고 서로 영향을 미치고 있음을 알 수 있다.

• 대한치과보철학회지
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• 제33권4호
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• pp.705-717
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• 1995

In clinical prosthetic dentistry the occlusal planes were represented to the dental arch form sagittally and composed of the occlusion morphologically. From now on the determinations of the occlusal planes were done through the facebow transfer and the cephalometric radiography, but they were not exact method for the diagnosis of the stomagnathic function. The purpose of this study is to examine the sagittal characteristics of occlusal planes using panoramic view between the normal subjects and the subjects with stomatognathic dysfunction. 60 normal subjects and 16 subjects with stomatognathic dysfunction were slectec for this investigation. We measured the inclination of occlusal planes to Frankfurt Horizontal plane. The occlusal planes were divided into 4 groups : 1) The plane between the midpoint of upper central incisor and the mesiobuccal cusp of upper 1st molar, 2) The plane between the midpoint of upper central incisor and the mesiobuccal cusp of upper 2nd molar, 3) The plane between the midpoint of upper central incisor and the distobuccal cusp of upper 2nd molar, 4) The plane between the mesiobuccal cusp of 1st molar and the distobuccal cusp of 2nd molar. The results were as follows : 1) The occlusal planes could be determined very easy by using panoramic view, 2) Among the angles between the occlusal planes and the FH plane, the angles related with the 2nd molar were more steep than those of the 1st molar. The angle between the 1st molar and the 2nd molar is the most steep in the other angles. 3) In the angles between occlusal planes and FH plane, the subjects with stomatognathic dysfunction were more significant steep(p<0.05) than the normal subjects.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권2호
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• pp.185-189
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• 2011

Tooth impaction represents the stop of eruption by clinical and radiographical disturbance in eruption path or the dislocation of tooth germ. The most common factor in tooth eruption disorders are spacial deficiency with other causes reported to be odontogenic tumors, periodontal ligament injury, etc. Impaction of the mandibular second molar is relatively rare and reported in about 3 out of 1,000 people. Because the second molars tend to erupt in a mesial direction, this situation can lead to serious problems if untreated, including dental caries, periodontal disease and root resorption of the first molar. Treatment of this problem includes, surgical repositioning and orthodontic forced eruption. Because each procedure have the definite advantages and disadvantages, and influenced by circumferential environment, these have limits for successfu1 recovery as independent treatment. In a case at St. Mary's Hospital, we performed successful correction of a horizontal impacted mandibular second molar using a miniplate skeletal anchorage system. We introduce this treatment as a valid method for an impacted second molar and consider a oromaxillofacial surgeon's role in tooth movement treatment.

• 대한치과교정학회지
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• 제42권3호
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• pp.110-117
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• 2012

Objective: In this study, we measured the cortical bone thickness in the mandibular buccal and lingual areas using computed tomography in order to evaluate the suitability of these areas for application of temporary anchorage devices (TADs) and to suggest a clinical guide for TADs. Methods: The buccal and lingual cortical bone thickness was measured in 15 men and 15 women. Bone thickness was measured 4 mm apical to the interdental cementoenamel junction between the mandibular canine and the 2nd molar using the transaxial slices in computed tomography images. Results: The cortical bone in the mandibular buccal and lingual areas was thicker in men than in women. In men, the mandibular lingual cortical bone was thicker than the buccal cortical bone, except between the 1st and 2nd molars on both sides. In women, the mandibular lingual cortical bone was thicker in all regions when compared to the buccal cortical bone. The mandibular buccal cortical bone thickness increased from the canine to the molars. The mandibular lingual cortical bone was thickest between the 1st and 2nd premolars, followed by the areas between the canine and 1st premolar, between the 2nd premolar and 1st molar, and between the 1st molar and 2nd molar. Conclusions: There is sufficient cortical bone for TAD applications in the mandibular buccal and lingual areas. This provides the basis and guidelines for the clinical use of TADs in the mandibular buccal and lingual areas.

• Journal of Oral Medicine and Pain
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• 제18권1호
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• pp.107-117
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• 1993

The author has taken intraoral standard films by the paralleling technique of 6414 teeth in 838 patients ranged from early twenties to early sixties and analysed the change of pulp cavity in the mandibular posterior teeth by ageing. The obtined results were as follows : 1. There was no significant difference between the right and left teeth. 2. The degree of change of pulp cavity in female was higher than that in male. 3. The change of pulp cavity was increased by ageing. 4. The correlation between the degree of change of pulp cavity inmandibular posterior teeth (X) and age (Y) were : Male 1st premolar Y=13.22X3.37+ r=0.79 2nd premolar Y=12.09X+3.65 r=0.79 1st molar Y=11.90X+1.25 r=0.78 2nd molar Y=10.51X+10.43 r=0.83 Female 1st premolar Y=13.66X-2.49 r=0.86 2nd premolar Y=13.63X-2.42 r=0.86 1st molar Y=12.42X-1.44 r=0.79 2nd molar Y=11.42X+5.91 r=0.84