• Journal of the korean academy of Pediatric Dentistry
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• v.51 no.1
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• pp.55-65
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• 2024

This study aimed to assess the accuracy of tooth widths, intermolar widths, and arch lengths acquired through two intraoral scanners, including iTero Element Plus Series (Align Technology, Santa Clara, CA, USA) and Trios 4 (3Shape, Copenhagen, Denmark), specifically on mixed dentition. A total of 30 subjects were divided into 2 groups, each undergoing both alginate impressions and intraoral scanning using either the iTero or Trios scanner. The plaster models were measured with a caliper, while the digital models were measured virtually. In the iTero group, all tooth width measurements exhibited differences compared to the plaster values, except for maxillary left lateral incisors (p = 0.179), mandibular right (p = 0.285), and left (p = 0.073) central incisors. The Trios group did not display significant differences in any of the tooth width measurements. Intermolar width comparisons for both groups indicated differences, except for mandibular primary canine to primary canine values (p = 0.426) in the iTero group. Regarding arch length, the mandibular anterior, maxillary right, and left arch lengths in the iTero group demonstrated larger caliper values than those of iTero. Conversely, in the Trios group, all parameters showed smaller caliper values, especially in upper anterior, maxillary right, mandibular right, and mandibular left arch lengths with significance (p = 0.027, 0.007, 0.003, and 0.047, respectively). Despite the differences between the two groups, digital models might be clinically suitable alternatives for plaster models. Pediatric dentists should carefully assess these differences, as a comprehensive evaluation would result in precise orthodontic treatment planning and favorable outcomes for young patients with mixed dentition.

• Journal of the korean academy of Pediatric Dentistry
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• v.10 no.1
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• pp.115-122
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• 1983

The author surveyed 2,082 schoolchildren (Male: 1,078, Female: 1,004) from 7 to 12 years old in "N" primary school in kwang Ju City, and studied on 304 schoolchildren (Male: 176, Female: 128) having maxillary median diastema. The results were as follows: 1. The prevalence of maxillary median diastema was 14.6%, and it showed the greater rate at the boys than at the girls and the highest rate at 8 years old in the both sexes. 2. The maxillary median diastema showed decreasing tendency with ageing. 3. The frenum distance in children without local factors showed no change and the divergent degree of maxillary median diastema showed decreasing tendency after the eruption of maxillary lateral incisors. 4. The rate of maxillary median diastema associated with local factors was 37.8% and it showed increasing tendency with ageing. 5. The prevalence of median diastema according to etiology was as follows; rotated tooth; 12.2%, supernumerary teeth; 10.9%, abnormal frenum; 9.5%, peg lateralis; 7.2%, open bite; 2.6%, abnormal pattern of interseptal alveolar bone; 2.6%, missing lateral incisor; 0.7%, tooth size discrepancy; 0.3%.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.387-393
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• 2009

The purpose of this study was to assess the relationship between interdental spaces and proximal caries in maxillary anterior primary teeth. 555 children aged 3-7 inhabit in Iksan were divided into two groups, depending on the presence of interdental space which was detected by a dental explorer. They were determined to have proximal caries if cavity was formed or the enamel surface was softened. The results were as follows : 1. Regarding interdental spaces, 77.4% had primate spaces; 54.4% had developmental spaces between central and lateral incisor, and 39.0% between central incisors. 2. Interproximal caries incidences in right primary canine, lateral incisor, and central incisor were 6.3%, 14.7%, and 33.5%, respectively. Also interproximal caries incidences in left primary central incisor, lateral incisor, and canine were 33.7%, 16.0%, and 4.7%, respectively. 3. Children with more interdental spaces had less caries incidence, but the relationship was weak(r=-0.024). 4. The mean caries incidence was higher in absence of interdental space of maxillary primary incisors than in presence of space. The mean caries incidence with no interdental space was twice as high as that with presence of interdental space.

• The korean journal of orthodontics
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• v.18 no.2
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• pp.407-420
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• 1988

The primary objective of this study was to make the prediction percentile tabulation of the sum of mesiodistal widths of the unerupted permanent canines and premolars derived from the sum of mesiodistal widths of the erupted permanent incisors in normal and crowding groups. Crowding group consisted of 85 pairs of dental casts (42 males and 43 females) with more than 4mm of crowding in anteriors. Normal group consisted of 109 pairs of dental casts (65 males and 44 females) with less than 1mm of spacing or crowding in anteriors. The mesiodistal crown diameters of permanent teeth were measured from the dental casts using the sliding calipers (Mitutoyo Co., Japan). From the study, the obtained results were as follows: There were not significant differences between male and female in both groups on the basis of the ratios between the sum of mesiodistal widths of incisors and the sum of mesiodistal widths of canines and premolars. There was not significant difference between two groups on the basis of the ratio between the sum of mesiodistal widths of mandibular incisors and the sum of mesiodistal widths of mandibular canines and premolars and was significant differences between two groups on the basis of the ratio between the sum of mesiodistal widths of mandibular incisors and the sum of mesiodistal widths of maxillary canines and premolars. There was significant difference between two groups on the basis of the ratio between the sum of mesiodistal widths of maxillary incisors and the sum of mesiodistal widths of mandibular canines and premolars. There was significant difference between two groups on the basis of the ratio between the sum of mesiodistal widths of maxillary incisors and the sum of mesiodistal widths of maxillary canines and premolars. The percentile prediction tabulations were made in an attempt to predict the sum of mesiodistal widths of the unerupted permanent canines and premolars derived from the sum of mesiodistal widths of the erupted permanent mandibular incisors in each group. The percentile prediction tabulations were made in an attempt to predict the sum of mesiodistal widths of the unerupted permanent canines and premolars derived from the sum of mesiodistal widths of the erupted permanent maxillary incisors in each group.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.519-525
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• 2010

Ectopic eruption means the eruption of the tooth in an abnormal position due to multiple factors, which found most frequently in maxillary fist permanent molars, mandibular lateral incisors and maxillary permanent canines. Ectopic eruption of the maxillary first permanent molar occurs when the molar erupts with a more mesial angulation than normal, and locks itself in an atypical resorption on the distobuccal root of the second primary molar. The maxillary first permanent molar plays important roles for mastication and occlusion, so ectopically erupted maxillary first permanent molars should be relocated into proper position. Treatment options are separation by insertion of the brass wire or elastic rings, preparation of distal aspect of the maxillary second primary molar, using fixed or removable appliance with finger spring, and placement of space maintainer or space regainer after extraction of the maxillary second primary molar. We report three cases treated of ectopically erupted maxillary first permanent molar by re-setting of stainless steel crowns, placement of brass wire and using active plate. We could find out distal movement of maxillary first permanent molars into proper position and normal occlusion.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.10 no.1
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• pp.8-15
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• 2001

The Class III malocclusion classified in two types of Skeletal Class III and Pseudo Class III. In the case of the maxillary deficiency, the protraction H-G(facemask) with Bonded RPE can be used. For children with A-P and vertical maxillary deficiency, the preferred treatment is to move the maxilla into a more anterior and inferior position, which also increases its size as bone is added at the posterior and superior sutures. Successful forward repositioning of the maxilla can be accomplished before age 8. To resist tooth movement as much as possible, the maxillary teeth should be splinted together as a single unit. The maxillary appliance must have hooks for attachment to the facemask that are located in the canine-primary molar area above the occlusal plane. The facemask usually worn until a positive overjet of 2-5mm is achieved interincisally. Occipital chin cup is successful in those patients who can bring their incisors close to an edge-to-edge position when in centric relation. This treatment is particularly useful in patients who begin treatment with a short lower anterior facial height, as this type of treatment can lead to an increase in lower anterior facial height. If the pull of the chin cup is directed below the condyle, the force of the appliance may lead to a downward and backward rotation of the mandible.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.611-616
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• 1994

A major cause of missing permanent incisors is congenital abscence and extraction because of trauma and pathologic condition. The request for restoration of missing or spaced anterior teeth is common in dental practice. Problems, such as the tilting, drifting, and rotation of teeth adjacent to the space, complicate the restoration of apperance, and a normally simple restorative dental procedure may become difficult. There are two primary treatment alternatives to improving a dentition's irregular and spaced apperance-closing the space by orthodontic means or providing a prosthesis to disguise the space. The treatment choice depends on many variables, but, as a general rule, patients with a normal overbite, overjet, and buccal relationship are better treated by maintaining the sapce and providing a prosthesis, either fixed or removable. This case report presents two cases : Traumatic loss of maxillary right and left central incisors, Extraction of malformed mandibular right central inciosr. The loss of central incisor space was regained by the fixed-removable and fixed orthodontic appliance, and then Maryland bridge was cemented.

• Journal of the korean academy of Pediatric Dentistry
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• v.7 no.1
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• pp.53-61
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• 1980

The purpose of this study was to statistically evaluate the spacing of primary dentition according to whether or not a space existed and measurement of amount of space in 205 children (male 114, female 91) from 2 to 6 years of age. The results were as follows; 1. In the incidence of interdental space on each region, spacing between the primary lateral incisors and primary canine in maxilla and between the primary canine and 1st primary molar in mandible showed the highest percentage, on the other hand, spacing between the 1st and 2nd primary molars in both jaw showed the lowest percentage. 2. In the kinds of interdental space, the state of primate space and other space together showed the highest percentage, and in the degree of spacing, $S_2$ showed the highest percentage in both jaw. 3. In the incidence of primate space, maxillary primate space showed higher percentage than mandibular primate space in bilateral case. 4. In the type of arch form, spaced arch showed higher percentage than closed arch and about the half of closed arch showed crowding. 5. In both Jaw, available space showed incisor segments, canine segments, and premolar segments in order of amount, and there were not statistically significant differences of sex or jaws in the amount of available space.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.1
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• pp.60-65
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• 2013

The term 'triple tooth' is used to describe a rare dental abnormality in which three teeth appear to be joined. The literature contains many reports of joined primary teeth; most cases have involved, however, the joining of two teeth, and only rarely three teeth. Triple tooth has clinical problems such as dental caries, esthetic problems, malocclusions, and periodontal problems. Therefore, it may require multi-disciplinary approach. The present study describes rare case of triple tooth between maxillary primary central and lateral incisors and a supernumerary tooth. An one-year, eleven-month old girl was seen for evaluation of swelling in the labial gingiva above a right maxillary triple tooth. She experienced traumatic dental injury in that area three weeks ago. Intraoral examination revealed an abscess and fistula in the region of the triple tooth. A radiographic examination showed that right lateral incisor was missing. Endodontic treatment and composite resin restoration was performed on the triple tooth. After follow-ups of 7 months period, there were no marked complications.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.64-75
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• 2019

The purpose of this study was to obtain instructions for size selection of prefabricated crown and tooth reduction by 3-dimensional analysis of the size and shape of the maxillary primary central and lateral incisors and prefabricated crowns (celluloid strip, resin veneered stainless steel, and zirconia crowns). The maxillary primary central and lateral incisors of 300 Korean children was scanned with three types of prefabricated crown to create standard three-dimensional tooth models and prefabricated crowns. The shapes of the prefabricated crowns and natural teeth were compared according to four parameters (mesio-distal width, height, labio-palatal width, and labial surface curvature coefficient) and calculated the amount of tooth reduction required for each prefabricated crown. The size 2 resin veneered stainless steel crown, size 1 zirconia crown, and size 2 celluloid strip crown were most similar in shape to the primary central incisor. The size 3 rein veneered stainless steel crown, size 2 zirconia crown, and size 3 celluloid strip crown were most similar to the primary lateral incisor. The amount of tooth reduction was similar in both maxillary primary central and lateral incisors. The incisal reduction was greatest for the zirconia crown. At the proximal surface, the zirconia and celluloid strip crowns required a similar amount of tooth reduction, but more than the resin veneered stainless steel crown. The labial surface reduction was greatest for the zirconia crown. The degree of lingual surface reduction was not significant among the three prefabricated crowns. Among the assessment parameters, mesio-distal crown width was the most important for choosing a prefabricated crown closest to the actual size of the natural crown.