• The korean journal of orthodontics
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• v.12 no.2
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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).

• The korean journal of orthodontics
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• v.37 no.2 s.121
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• pp.150-158
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• 2007

Objective: The aim of this study was to determine the relationship between the status of a unilateral palatally impacted maxillary canine (as seen on the panoramic radiograph) and the orthodontic treatment duration. Methods: A total of 36 subjects were chosen (8 males and 28 females, $13.7{\pm}2.5$ years). All patients had undergone orthodontic traction of the impacted canine after a closed flap surgery. The position of impacted canine on the panoramic radiograph was traced and calculated with regard to the treatment duration. Results: The canine overlap over the lateral incisor (COGr) had significant statistical difference between the short-term and the long-term treatment duration groups (divided by average treatment time of 21 months) (p<0.05). Multiple regression indicated that the variables of significance (with treatment duration as the dependent variable) were the canine vertical height from the occlusal plane $(HCV,\;r^2=0.115;\;p<0.05)$ and the mandibular anterior width $(MnDW,\;r^2=0.142;\;p<0.05)$. The treatment duration, the canine angle to the incisor midline (CA), and HCV decreased from primary dentition (under 12 yrs) to permanent dentition (15 yrs). Howerer, these increased again at the adolescent ages (over 16 yrs). Conclusion: These findings suggested that orthodontic treatment of a palatally impacted canine would show good prognosis at an age of early permanent dentition with the canine showing smaller CA and HCV.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.630-635
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• 1999

Transposition has been described as an interchange of position of permanent tooth and is a relatively rare dental anomaly. Transposition of teeth may occur both in the maxillary and mandibular arches. but it appears more often in the maxilla of individual teeth, the maxillary canine is the most often involved. A canine transposes most often with a first premolar and less frequently transposes with a lateral incisor. Incomplete transposition is a condition describing an interchange in the position of the crowns of two permanent teeth, while the root apices remain in their relative position. Complete transposition is a situation in which both the crowns and entire root structure are transposed. The etiologic factors of transposition are tooth buds interchange, retained deciduous canines, migration of the erupting canine, trauma to deciduous teeth etc. This report describes a case of a transposition between a maxillary left canine and a lateral incisor and impaction of a maxillary left central incisor due to trauma to deciduous dentition.

• Journal of the korean academy of Pediatric Dentistry
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• v.6 no.1
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• pp.43-52
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• 1979

The purpose of this study was to finding out the relationship between the tooth calcification and eruption of the mandibular permanent teeth in Korean. This study was undertaken in 592 children at ages from 3 to 13 years who had good oral condition by means of panoramic roentgenographic analysis. The following results were obtained. 1. The mean ages of crown completion were as follows; Canine 1st. Premolar 2nd. Premolar 1st. Molar Male 6yrs. 4mos. 6yrs. 8mos. 7yrs. 6mos. 7yrs. 6mos. Female 5yrs. 11mos. 6yrs. 5mos. 7yrs. 2mos. 3yrs. 3mos. 2. Each tooth started to move toward occlusion at approximately stage 6 or after crown completion. 3. The highest increment in eruption rate was at about 1/3~1/2 completion of root and ages at 10-11 years in male, 9-10 years in female. 4. Eruption period of both sexes were as follows; Canine: 6-12years 1st. Premolar: 7-12 years 2nd. Premolar: 7-13 years 1st. Molar: 3-7 years 5. The eruption was completed before the root completion. 6. The sequence of eruption and calcification was 1st. Molar-Canine-1st. Premolar-2nd. Premolar in both sexes.

• The Journal of the Korean dental association
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• v.58 no.7
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• pp.398-403
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• 2020

Odontogenic anomalies can occur as a result of conjoining defects. These include fusion, gemination and concrescence. The presence of fused teeth can lead to various clinical problems, including the aplasia of permanent successor, the supernumerary teeth and delayed eruption of permanent teeth. In general, the supernumerary teeth associated with fusion is mainly found in the maxillary anterior region. This report describes rare cases of supernumerary tooth associated with fused teeth of mandibular primary lateral incisor and canine. In the first case, fused teeth was extracted. The supernumerary teeth was erupted at canine space. The second case is still being observed. Extraction of fused teeth and observation of supernumerary teeth is planned.

• The Journal of the Korean dental association
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• v.11 no.5
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• pp.313-316
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• 1973

970 children visited attached hospital, S.N.U, were taken orthopantomograph. Of those children, there were 14 patients who have primary fused teeth. The author observed those cases and got following results. 1) Incidence of primary fused teeth was higher in female. 2) In the order of frequency, fused teeth of mandibular right primary lateral incisor and canine were 9 and that of mandibular left primary lateral incisor and canine were 4, and there was only one case in maxillary. 3) 13 cases showed the congenital absence of lateral incisor of the corresponding permanent teeth. 4) Incidence of fused teeth was 1.44%.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.693-702
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• 2005

Accurate timing and sequence of eruption of permanent teeth are indicies of growth and essential for pediatric dentistry and pediatric clinical orthodontics. From the children brought to the Yonsei Dental Hospital during 2001 to 2003, 654 boys and 542 girls, ranging in age from five to fourteen years, were selected and analysed. The following was concluded. 1. Eruption time of maxillary teeth is 6.81 years in boys, 6.78 years in girls for central incisor, 8.30 years in boys, 7.98 years in girls for lateral incisor, 10.28 years in boys, 10.04 years in girls for canine, 9.74 years in boys, 9.90 years in girls for first premolar, 10.87 years in boys, 10.41 years in girls for second premolar, 6.25 years in boys, 6.54 years in girls for first permanent molar, 12.21 years in boys, 12.03 years in girls for second permanent molar 2. Eruption time of mandibular teeth is 6.00 years in boys, 6.06 years in girls for central incisor, 6.99 years in boys, 6.74 years in girls for lateral incisor, 9.83 years in boys, 9.17 years in girls for canine, 9.92 years in boys, 9.75 years in girls for first premolar, 10.66 years in boys, 10.39 years in girls for second premolar, 5.99 years in boys, 5.75 years in girls for first permanent molar, 11.92 years in boys, 12.17 years in girls or second permanent molar. 3. The following eruption sequence was observed the first permanent molar erupted first, followed by the central incisor, the lateral incisor, the first premolar, the canine, the second premolar and the second permanent molar in the maxilla. The first permanent molar erupted first, followed by the central incisor, the lateral incisor, the canine, the first premolar, the second premolar and the second permanent molar in the mandible.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.2
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• pp.233-239
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• 2010

Space loss of dental arch can appear when the proper position of teeth within the dental arch changes by a certain cause, because the balance of force makes changes about tooth position as well as alignment. The causes of space loss include proximal caries, early extraction, congenital missing of a tooth and hypodontia, etc. Among those causes of space loss, congenital missing of a tooth is more rarely observed in the primary dentition than in the permanent dentition. Congenital missing in the primary dentition is associated with that in the permanent dentition. Furthermore, it can cause space problem, such as mesial tilting or drift of adjacent teeth, space loss for permanent successors and dental arch constriction, etc. Primary lateral incisors is the most commonly involved, in the maxilla rather than in the mandible, but primary canine is rarely reported. In this patient, who visited the department of pediatric dentistry at Yonsei university dental hospital, it was observed that the maxillary right primary canine was congenitally missing and an odontoma was found insteadly. However, neither the space loss for the congenitally missing primary canine nor midline deviation is remarkable during the 2-year-10-month observation period. In addition, any clinical or radiographical symptom did not occur in spite of odontoma. Therefore, surgical enucleation of odontoma is planned according to the eruption of permanent lateral incisor or canine, unless eruption failure of permanent lateral incisor or canine nor cystic change around the odontoma is occurred. Through further evaluation, space maintainer or orthodontic treatment may be necessary.

• The Journal of the Korean dental association
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• v.11 no.12
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• pp.787-799
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• 1973

Surveying the calcification degree of permanent tooth crown in 719 Korean children (Male 387, female 332) from 2 to 10 years old by orthopantomograph, the author got the following results. 1. Female was earlier than male in calcification of permanent teeth. 2. The results of the complete calcification of the permanent tooth crown were as follows. 3. The completion of calcification in the mandibular crown was seen earlier than that of the maxilla. 4. The order of calcification in permanent tooth crowns was as follows : 1 st molar, central incisor, lateral incisor, canine, 1st premolar, 2nd premolar, and 2nd molar. 5. The completion of calcification of the permanent crowns in Korean children was slightly retarded comparing with the Japanese and the American children.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.6
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• pp.528-532
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• 2010

Introduction: There are few reports on tooth eruption through Bio-Oss grafts. To our knowledge, there are no reports on whether teeth can erupt normally through the grafts. The aim of this study was to examine the effect of Bio-Oss grafts on tooth eruption in a canine model. Materials and Methods: In five 10-week-old dogs, the deciduous third mandibular molars in one jaw quadrant of each animal were extracted and the fresh extraction sockets were then filled with Bio-Oss particles (experimental side). No such treatments were performed on the contralateral side (control side). A clinical and radiological evaluation was carried out every other week to evaluate the eruption level of the permanent third mandibular premolars and compare the eruption levels between the two sides. Results: At week 4 after the experiment, the permanent third premolars began to erupt on both sides. At week 12, the crown of the permanent third premolar emerged from the gingiva on both sides. At week 20, the permanent third premolars on both sides erupted enough to occlude the opposing teeth. No significant differences were found between the control and experimental sides in terms of the eruption speed of the permanent third molars. Conclusion: These findings demonstrate that the grafting of Bio-Oss particles into the alveolar bone defects does not affect tooth eruption.