• The korean journal of orthodontics
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• v.48 no.6
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• pp.367-376
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• 2018

Objective: This study was performed to investigate the changes in alveolar bone after maxillary incisor intrusion and to determine the related factors in deep-bite patients. Methods: Fifty maxillary central incisors of 25 patients were evaluated retrospectively. The maxillary incisors in Group I (12 patients; mean age, $16.51{\pm}1.32years$) were intruded with a base-arch, while those in Group II (13 patients; mean age, $17.47{\pm}2.71years$) were intruded with miniscrews. Changes in the alveolar envelope were assessed using pre-intrusion and post-intrusion cone-beam computed tomography images. Labial, palatal, and total bone thicknesses were evaluated at the crestal (3 mm), midroot (6 mm), and apical (9 mm) levels. Buccal and palatal alveolar crestal height, buccal bone height, and the prevalence of dehiscence were evaluated. Two-way repeated measure ANOVA was used to determine the significance of the changes. Pearson's correlation coefficient analysis was performed to assess the relationship between dental and alveolar bone measurement changes. Results: Upper incisor inclination and intrusion changes were significantly greater in Group II than in Group I. With treatment, the alveolar bone thickness at the labial bone thickness (LBT, 3 and 6 mm) decreased significantly in Group II (p < 0.001) as compared to Group I. The LBT change at 3 mm was strongly and positively correlated with the amount of upper incisor intrusion (r = 0.539; p = 0.005). Conclusions: Change in the labial inclination and the amount of intrusion should be considered during upper incisor intrusion, as these factors increase the risk of alveolar bone loss.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.41-56
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• 2018

The purpose of this study was to provide clinical recommendations for restoration with selection of the most similar zirconia crown by 3-dimensional analysis of the shape of the maxillary primary central and lateral incisors in Korean individuals and prefabricated zirconia crowns. The average shape of the sound maxillary primary central and lateral incisors in 300 children was reproduced by 3-dimensional scanning. Zirconia crowns of 4 manufacturers (NuSmile $ZR^{(R)}$ Crown, Cheng $Crowns^{(R)}$, Kinder $Krowns^{(R)}$, and EZ $Pedo^{(R)}$ Crown) were scanned 3-dimensionally, and coordinates for comparison of the shape were measured to evaluate the similarity between the teeth and crowns. The most similar crowns were selected by comparing the mesiodistal length, crown height, crown shape ratio, distance between the same coordinates of a tooth and crown, the radius of curvature of the labial surface, and the volume. As a result of analysis, Cheng $Crowns^{(R)}$ size 3 and NuSmile $ZR^{(R)}$ Crown size 2 were the most similar crowns in the maxillary primary central and lateral incisors, respectively. Scanning the inner surface of the crowns and evaluating the amount of tooth reduction required suggested that an overall lesser amount of tooth reduction compared to that presented by the manufacturer's guidelines should be performed.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.93-100
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• 2019

The objective of this study was to analyze the color distribution of the maxillary primary central incisors and the relationship between the color of each tooth region by dividing tooth into incisal, middle and cervical region using a spectrophotometer. The subjects were 105 sound maxillary primary central incisors from 3 to 6 years old children. Color measurements were performed by one dentist using same protocol. CIE $L^*$, $a^*$, $b^*$, $C^*$, $h^*$ data and the best matched shades with coverage error were obtained for each region and whole labial surface. There was a significant difference in CIE $L^*$, $a^*$, $b^*$ according to regions and the difference in color between each region was more than the clinical acceptance. By correlating the relationship between the color of each region with $L^*$, $a^*$, $b^*$ values, it is possible to extrapolate the color of other region with one color or to be used as data for making restorative materials and prostheses that are more aesthetically pleasing for primary teeth.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.11 no.2
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• pp.72-75
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• 2015

Cerebral palsy is one of the most common disabilities of childhood, which affects movement and co-ordination. Individuals with cerebral palsy are susceptible to traumatic dental injuries. High occurrence of Class II malocclusion with prominent maxillary incisors appears to increase risk of trauma. However, due to fear of behavior management and lack of cooperation, clinicians have avoided orthodontic treatment in cerebral palsy patients. This case report demonstrates that modified rapid maxillary expansion can be used as a simple and effective method to correct ectopic eruption of maxillary incisor in cerebral palsy patient.

• The Korean Journal of Oral and Maxillofacial Pathology
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• v.42 no.6
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• pp.183-187
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• 2018

The supernumerary tooth which is extra tooth in comparison to normal dentition is one of the developmental problems. The most common type of supernumerary tooth is mesiodens which may cause several complications like delayed eruption, crowding, spacing et al. Moral Incisor Hypomineralization (MIH) describes the clinical appearance of enamel hypomineralization of systemic origin affecting one or more permanent first molars that associated frequently with affected incisors. We report a case of a 6 - year - old boy who visited our clinic for removal of mesiodentes. The patient was diagnosed by mesiodentes and MIH by clinical examination and radiographic examination. Under local anesthesia, Mesiodentes were removed surgically. The demarcated opacities, a feature of MIH, were observed in the removed mesiodentes. After removal of mesiodentes, the maxillary central incisors erupted normally and in order to manage the teeth affected MIH, follow-up and fluoride varnish application were done every 3 months.

• The korean journal of orthodontics
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• v.29 no.6 s.77
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• pp.689-698
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• 1999

Although the purpose of orthodontic treatment is to increase the function and aesthetics of the jaws as well as to increase stability, there are side effects from the treatment itself such as root resorption and alveolar bone resorption. Such resoiption of the apical root is unpredictable and may even proceed into the dentin layer. Once the process has begun, it is irreversible. By evaluating the effects of different oral habits, especially that ef nail biting, and their correlation with the root and the periodontal tissues, the appropriate biomechanics for orthodontic treatment can be taken into consideration. The possibility of root resorption and alveolar bone loss during orthodontic treatment can also be considered. Also, any legal problems that might occur may be pondered as well. Among the male md female patients of the ages 10~15, 63 were chosen as the test group with known nail biting habits at time of examination and within the same age range those without nail biting habits as the control group. The test group was composed of 30 males and 33 females. The control group had 31 males and 32 females. The result from this study were as follows : 1. Of the 63 patients of both the test and control groups, the male-to-female-ratio was 1:1, and had no statistically significant difference in male and female root resorption. 2. In comparing crown length of the test and control groups, no significant difference existed, but in root length, maxillary and mandibular right and left central incisors and mandibular right lateral incisors had a smaller value. (p<0.001) 3. Average crown-to-root ratio of the test group on the periapical view show a noticeably high value for the maxillary and mandibular right and left central incisors and mandibular right and left lateral incisors. (p<0.01) 4. In comparing and evaluating the alveolar bone loss measured from the cemento-enamel junction to the alveolar bone crest, mesial surfaces of the maxillary and mandibular right and left central incisors and distal surface of maxillary right central incisor of the test group showed greater loss of crestal bone than the control. (p<0.05)

• Journal of Periodontal and Implant Science
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• v.27 no.1
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• pp.235-248
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• 1997

The purpose of this study was to investigate the width of attached gingiva of 414 subjects with healthy gingiva, or early stage of gingivitis. We compared the differences according to the tooth location, age (Yonger group : $14{\sim}30$, Older group : $31{\sim}67$) and gender. In addition, we compared the width of attached gingiva in the subjects with less than 2 sites of gingival recession($Re{\leq}2$) and the subjects with more than 3 sites of gingival recession($Re{\geq}3$) to study the relationship between the gingival recession and the width of attached gingiva. The results were as follows : 1. The width of keratinized gingiva was widest in maxillary incisors($5.3{\pm}1.4mm$) and narrowest in mandibular right 1st bicuspid and mandibular right and left 2nd molars($3.5{\pm}1.1mm$). 2. The width of attached gingiva was widest in maxillary right central incisor($3.8{\pm}1.5mm$) and narrowest in mandibular right 2nd molar($1.2{\pm}1.0mm$). 3. In the comparison between the age groups, the width of keratinized in older group was significantly (p<0.05) wider than that in younger group in maxillary right and left 1st bicuspids, mandibular right and left 1st and 2nd molars, maxillary right and left cuspids and mandibular right 1st bicuspid. There was no significant difference in the width of attached gingiva between the two groups except for maxillary right and left 1st molars and maxillary left 2nd molar. 4. In the comparison between male group and female group, in maxillary right and and left lateral incisors and cuspids, mandibular right and left cuspids and 1st bicuspids, the width of attached gingiva in female was significantly(p<0.05) wider than that in male group. 5. In the comparison between the Re 3 group and Re 2 group, there was no significant difference except for maxillary right and left 2nd molars and maxillary left 1st molar. 6. The frequency of gingival recession was m the order of mandibular right 1st bicuspid(16.6%), maxillary right 1st bicuspid(13.7%), maxillary and mandibular left 1st bicuspids (13.4%), mandibular left cuspid (10.5%), maxillary left and mandibular right cuspids(10.1%) and maxillary right cuspid(7.9%).

• The Journal of the Korean dental association
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• v.20 no.3 s.154
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• pp.233-237
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• 1982

A review of the literature was presented, illustrating the effect that gingivally retained orthodontic elastic bands have on the periodontal tissues. A case report was presented for treatment of mobile maxillary central incisors secondary to a subgingival elastic band. Following surgical removal of elastic band and periodontal debridement, the teeth were successfully retained with active orthodontic appliances. Until a harmless radiopaque medium can be safely incorporated into elastic bands, extreme caution in their use should be observed. Not only should all attempts be made to anchor the elastic bands to the clinical crown, but the patient should receive through instructions in their placement and removal.

• Journal of Oral Medicine and Pain
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• v.7 no.1
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• pp.41-46
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• 1982

The patient, 11 yeats old male was examined for routine oral health care. He had been hospitalized for treatment of nephritis. Hos physical condition os mental retarded & undergrowth state. In oral examination, notch on cutting edge and screw-driver shaped crown of maxillary central incisors, narrow crown and dwarfed & pinched occlusal surface of lower first molars and scars(rhagades) on the angle of the lip were shown. We diagnosed the above symptoms as dental defects of congenital syphilis; Huchinson's inscisors and mulberry molar.

• Journal of Oral Medicine and Pain
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• v.6 no.1
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• pp.15-18
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• 1981

The author had selected the roots and root-canal as measurable parts and sought the area ratio by measuring the respective areas of the root. Further, heplotted out a root caual index and studied the correlation with age. The teeth used as reserch material were permanent maxillary central incisors of Korean female. Some 296 teeth of known age were selected on condition that there is no caries or filling material and that they were not malformed in showing normal signs in roentgenograms. The $3" {\times} 4"$ printing paper so as to measure easily. On the ocassion of measureing the area of measured parts with a planimeter (Koizumi, type kp-27, Japan), the cervical lines were joined up into a straight line on a photograph (Figure 1) Root canal index = Area of the root / Area of the root canal The results of the root canal index in Korean female age groups were as follows : 1. The root canal index of maxilary central incisor in women was 4.74 im 20 years of age, 5.44 in 30, 5.90 in 40, 6.32 in 50, 6.63 in 60 in the order. 2. Root canal index and age were in positive correlation ; there was a tendency that the root canal index increase as age advances. 3. The regression equation was as follows : Y = 5.36x + 7.71 (r = 0.54, n= 296 ) (Y = estimated age, x = root canal index)