• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.89-100
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• 2005

The purpose of this study was to analyze the morphometrics of primary second molar and permanent first molar. Samples were consisted of normal occlusion in the primary dentition(50 males and 50 females) and permanent dentition(43 males and 43 females). Their upper and lower plaster casts were used and their measuring points were decided, through 3-dimensional laser scanning(3D Scanner, DS4060, LDI, U.S.A.), fitting standard horizontal plane were made for measuring the intercuspal distance, volume of intercuspal area and section curve. The results were as follows; 1. Average distance from the fit plane to the cusp tips of mandibular primary second molar was smaller than any other tooth. (0.05-0.09 mm in male and 0.04-0.09 mm in female). 2. Intercuspal distances of mandibular primary second molar and permanent first molar were larger in male than in female. Especially, there was statistical significance in primary second molar(p<0.05). 3. Intercuspal distance between distobuccal and distolingual cusp was larger in maxillary primary second molar, except cross intercuspal distances. And distances between distal and distolingual cusp, in mandibular primary second molar, between mesiolingual and mesiobuccal cusp, in maxillary first molar, and between distolingual and mesiolingual cusp, in mandibular first molar were larger than any other intercuspal distance. 4. Volume of intercuspal area of primary second molar and permanent first molar was larger in mandible than in maxilla and that of permanent first molar was 1.40-1.75 times of primary second molar (p<0.05). Also it was larger in male than in female, but there was no statistical significance. 5. In most cases, section curves were wider and deeper in permanent dentition than in primary dentition. Except cross intercuspal distances, in maxilla, section curve between mesiobuccal and mesiolingual cusp was the deepest in both dentition. In mandible, section curve between distobuccal and distal cusp was the deepest in permanent dentition and between distolingual and distal cusp was the deepest in primary dentition.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.285-296
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• 2010

This study was implemented among 100 students of C College of Public Health who have healthy permanent dentition in order to measure the morphology and sizes of clinical crowns of permanent maxillary molars. The following are conclusions of this study. 1. The cusp height, crown width, crown thickness of clinical crowns appeared to be bilaterally symmetrical. 2. The strong development of the buccal groove showed to be superior in the right first molar. The appearance rate of the buccal pit was high in the right first molar also. 3. The type 4th cusp appeared as 100% in the left and right first molars, and 78%, 75% in the left and right second molars respectively. 4. The distal lingual cusp(DLC) size were bilaterally symmetrical in the type 4th cusp. 5. As for the distance between two cusp tips, it was large between mesial cusp tips in all of the first and second molars at both sides. 6. Development of the Carabelli's cusp was high in both the left and right first molars. 7. The appearance rate of the oblique ridge was 87.0% in the right first molar, 73.0% in the right second molar, 88.0% in the left first molar, and 73.0% in the left second molar. This is considered to be caused by people who have mild dental crown caries in their first molars. 8. The appearance rate of the mesial marginal ridge tubercle(DMRT) was high in both of the left and right first molars. That of the distal tubercle was 16.0% in the right first molar, 26.0% in the right second molar, 14.0% in the left first molar, and 21% in the left second molar.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.147-152
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• 2013

Purpose: The aim of this study was to propose the position of maxillary anterior teeth and intercanine width measurements based on the incisive papilla in accordance with the cephalic type and gender of dentate Korean adult with normal teeth alignment. Materials and methods: 42 students with Class I normal occlusion, without crowding or spacing, were selected from the Chonnam National University School of Dentistry. The lateral skull radiographs of the subjects were taken and were classified as different cephalic types, based on their PFH / AFH ratios. 42 casts of their maxilla were prepared and both the distance between the upper central incisors and the middle of the incisor papilla was measured with a vernier caliper (A) and the distance between the maxillary canine cusp tips (B) were measured. Statistical analysis was performed using SPSS version 15 and their significance was investigated. Results: For dolichocephalic group, the mean values for A and B were 8.43 (SD: 0.61) and 36.73 (SD: 2.17), respectively. The mean value for A was 8.51 (SD: 1.27) for the mesocephalic group and 8.76 (SD 1.03) for the brachycephalic group. The mean value for B was 35.91 (SD: 1.86) for the mesocephalic group and 37.34 (SD: 2.23) for the brachycephalic group. For the male group, the mean A value was 8.86 (SD: 1.04) and the mean B value was 37.60 (SD: 0.24). For the female group, the mean A value was 8.41 (SD: 0.93) and the mean B value was 36.18 (SD: 2.01). The difference between male and female group in A values were not statistically significant (P>.05). The B values of the male subjects were greater than those of the female subjects and was statistically significant (P<.05). Conclusion: 42 students with normal dentition and occlusion in korea, the distance from the incisive papilla and the incisal edge of maxillary central incisors had no difference in cephalic type or gender. However, the distance between the cusp tip of both canines had significant difference in gender where the male showed higher values than the female, while having no difference in cephalic types.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.4
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• pp.337-347
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• 2011

The basic structure of the primary crowns usually resemble their succeeding permanent teeth. However, maxillary second primary molars resemble ipsilateral first permanent molars. Accordingly in this study, odontometric data of the two teeth was obtained, then analyzed to verify the morphological relationship and sex difference between the two teeth. Dental study casts were examined for their mesiodistal and buccolingual width of the crowns, diameter of each cusps, and intercuspal distances. Photographs of the crowns were taken to measure the angles between each cusp tip. The results are as follows : 1. In boys, PrI, PaI, DBC angle, and MBC angle did not show any statistically significant difference between the two teeth(p>0.05), and moderate level of correlations were observed. 2. In girls, crown index, DBC angle, and MBC angle of the two teeth did not show any statistically significant difference(p>0.05), and moderate level of correlations were recognized. 3. Measurements that did not show statistically significant difference between the two teeth in both boys and girls were DBC angle and MBC angle(p>0.05). In DLC angle, however, statistically significant difference was observed(p<0.01). 4. Most of the measurements showed sex differences, except DBC angle, which did not show any sex difference in both teeth(p>0.05).

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.4
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• pp.214-219
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• 2019

Purpose: The aim of this study was to evaluate the correlation between inter-condylar width and inter-maxillary first molar width to present the criteria for prosthetic reconstruction of dental arch width in maxillary and mandibular fully edentulous patients. Materials and Methods: 120 Koreans (60 males and 60 females) who underwent the cone beam computerized tomography (Cone-beam CT) were selected. The Cone-beam CT images were analysed using Invivo 5.1. After reorientation of axis, inter-maxillary first molar width was measured by clicking both mesio-buccal cusp tip of maxillary first molar. And inter-condylar width was measured by clicking both middle points of condyles. The collected data were analysed with SPSS Version 20.0 and statistical significance of the correlation between inter-condylar width and inter-maxillary first molar width was verified by Pearson's correlation analysis. Results: The mean inter-condylar width of Korean was 105.9 mm, and that of male (108.3 mm) was statistically significantly wider than the female (103.4 mm). The inter-maxillary first molar width of Korean was 57.1 mm, and that of male (57.9 mm) was statistically significantly wider than the female (56.2 mm). Pearson's correlation analysis between inter-condylar width and inter-maxillary first molar width showed a Pearson correlation coefficient of 0.614 and statistically significantly positive correlation. Conclusion: Intercondylar width and inter-maxillary first molar width showed positive correlation and the average ratio of inter-condylar with and inter-maxillary first molar width was 1:0.54. Based on the results of this limited study, inter-condylar width can be used as a guide for setting up dental arch width in fully edentulous patient.