• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.397-406
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• 2002

The purpose of this study was to clarify the palatal arch length, width and volume in the primary and permanent dentition. 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 plaster casts were used and through 3-dimensional laser scanning(3D Scanner, DS4060, LDI, U.S.A.), cloud data, polygonization, section curve, loft surface and fit and horizontal plane were made for measuring the palatal arch length, width and volume(Surfacer 10.0, Imageware, U.S.A.). Correlation coefficients were calculated separately for males and females in each group(SPSS 10.0). The results were as follows : 1. Average distance from the fit plane to the points(tooth-tooth-palate) was greater in the permanent dentition than those of primary dentition. 2. Palatal volume was greater more than 3 times in the permanent dentition, especially it was greater in male compared to female with significance(p<0.05). 3. Palatal width of male was greater in the primary and permanent dentition but palatal length, only in the permanent dentition than that of female(P<0.05). 4. Correlation coefficients were statistically most significant between the palatal volume and size of posterior palatal width and total palatal length(r=0.401, r=0.450, r=0.678, r=0.654).

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.569-578
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• 2004

The purpose of this study was to clarify the palatal arch length, width and height in the primary and permanent dentition. Samples were consisted of normal occlusions both in the primary dentition(50 males and 50 females) and in the permanent dentition(50 males and 50 females). With their upper plaster casts were used and through 3-dimensional laser scanning(3D Scanner, DS4060, LDI, U.S.A.), cloud data, polygonization, section curve and loft surface, fit and horizontal plane were based to measure the palatal arch length, width and height(Surfacer 10.0, Imageware, U.S.A.). T-tests were applied for the statistical analyze of the data. The results were as follows : 1. In the measurement values, the values of the male were higher than those of the female except primary anterior palatal height. There were not only statistically significant differences in anterior palatal width(p<0.05) and posterior palatal width(p<0.01) in primary dentition but palatal width(p<0.05), anterior palatal length(p<0.01), middle and posterior palatal length(p<0.05) in permanent dentition between male and female. 2. In the indices of palate, there were statistically significant differences in height-length index(p<0.05) and width-length index(p<0.01) between male and female in primary dentition. In permanent dentition, there was statistically difference between male and female. 3. In the measurement values, posterior palatal width was increased most greatly. Posterior palatal height, anterior palatal width and anterior palatal length were followed by descending order. On the other hand, anterior palatal height and posterior palatal length were decreased. 4. In the indices of palate, the height-length index, the width-length index and posterior height-width index were increased, but the others were decreased.

• Korean Journal of Cleft Lip And Palate
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• v.7 no.1
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• pp.25-34
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• 2004

The present study was carried out to investigate the change of the palatal length after palatoplasty in congenital cleft palate. With the data from one hundred and twelve patients with cleft palate who had been treated at the Department of Oral and Maxillofacial Surgery of Chonnam University Hospital over a period of 10 years(April 1995 to April 2004). The epidemiological characteristics, the method of palate repair, the postoperative complications and the extent of palatal lengthening were investigated and analyzed statistically. Incomplete cleft palate occurs more frequently than complete cleft palate. Male were affected 2.1 times more than female in complete cleft palate, and female were affected 1.2 times more than male in incomplete cleft palate. Dorrance method and Wardill V-Y method were frequently used in repair of incomplete cleft palate. Wardill V-Y method, Furlow double opposing Z-plasty, two flap method, and Perko method were widely used in repair of complete cleft palate. The extent of palatal lengthening was greater in the incomplete cleft palate group(5.84 mm) than in the complete cleft palate group(4.71 mm), and in the Furlow double opposing Z-plasty group(5.70 mm) than in the push back palatoplasty group(5.33 mm). But no significant difference was noted. Palatal fistula and wound dehiscence were popular postoperative complications in cleft palate. These results indicate that the extent of palatal lengthening, which contributing to speech function, is a range of 3.5% to 24.0%(average 10.8%) after palatoplasty in cleft palate patients.

• The korean journal of orthodontics
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• v.35 no.1 s.108
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• pp.35-42
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• 2005

There is lack of data for the amount of vertical bone in the midpalatal region for miniscrew implantation. The purpose of this study was to measure the structure of the midpalatal suture area using CT image and V-works 4.0 program (Cybermed Inc, Seoul, Korea). CT images of 14 male and 14 female adults were reconstructed. In detail, it was 1) to measure the length of maxilla on the midsagittal plane 2) to measure vertical bone height in the midpalatal area 3) to establish the zone of safety for miniscrew implantation. The following results were obtained. The mean length of ANS-PNS was 51.08mm in males and 47.34mm in females. There was a statistically significant difference between males and females (p<0.05). The vertical bone height of the midpalatal suture area was above 0mm except for 6mm posterior from the central Point of ANS-PNS in males The zone of safety was located 19.43mm posterior from the ANS in males while it was 17.62mm in females along the palatal plane. These results support that the safety zone of the midpalatal area is suitable for screw implantation. Midpalatal miniscrew implantation is a powerful tool in modern orthodontics Through many applications. it can expand the modern orthodontic field.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.1
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• pp.25-35
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• 2020

The purpose of this study is to evaluate the morphological characteristics of the roots and roots canals of primary molar teeth using Cone-Beam Computed Tomography (CBCT). A total of 68 CBCT images of children aged 4 - 5 years was used for this study. A total of 160 molar teeth were analyzed. Various parameters such as the number of roots and canals, length of root and root canal, and the angulation and shape of the roots were analyzed. All maxillary primary molars had 3 roots. The presence of 2 root canals in 1 root was only observed in the mesiobuccal root of maxillary primary second molars. Most mandibular primary molars had 2 roots, and most mesial roots had 2 root canals. Concerning the length of the roots, the palatal root of the maxillary primary molar was found to be longest whereas the distobuccal root was shortest. In mandibular primary molars, the mesial root was longer than the distal root. In maxillary primary molars, the palatal root had the greatest angulation whereas the distal root has the greatest in mandibular molars. The root and root canals of maxillary primary molars were more curved in shape whereas mandibular primary molars were straight.

• Korean Journal of Cleft Lip And Palate
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• v.12 no.1
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• pp.33-40
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• 2009

구개열이 있으면 언어장애 음식섭취의 어려움, 구개범장근의 기능장애로 인한 이관의 개폐기능부전으로 중이의 액체고임, 부정교합등 여러 문제가 생길 수 있다. 따라서 구개성형술은 갈라진 경구개와 연구개를 막아주며 동적인 연구개를 만들어 주어 충분한 구개인두폐쇄를 하여 정상적 발음을 하는데 그 목표가 있다. 그 외에도 음식물을 정상적으로 섭취할 수 있고 중이염 및 난청을 일으킬 수 있는 기능을 개선시키고 정상적인 교합을 만들어주는데 있다. 위의 목표를 이루기 위해 지금까지 많은 수술 방법이 개발되었고 개선되어 왔다. 하지만 아직도 가장 효과적인 수술방법, 수술시기에 대하여 논쟁거리가 되고있다. 언어를 분명하게 하려면 연구개는 인두벽에 닿기 위해 후상방으로 올라가고 인두의 후벽과 측벽은 올라온 연구개에 닿으려고 수축함으로써 비인두와 구인두 사이의 공간이 좁아지게 됨으로써 가능하다. 따라서 발음이 정확하려면 비인두괄약(nasopharyngeal sphincter)을 합리적으로 만들어주어 비인두와 구인두를 분리해 주어야 한다. 비인두괄약을 조성해 주는 방법에는 구개범거근이 괄약기능을 할수 있도록 연구개내근성형술(intravelar veloplasty)을 시행하여 양편구개범거근을 횡위로 옮겨 연결하여 올림근 걸이(levator muscle sling)을 만드는 방법, 구개 연조직을 후방으로 밀어 구개 길이를 연장하는 방법, 인두 피판술을 하는 방법등이 있다. 구개범거근의 주행방향과 부착이 잘못되어 있는 것으로, 정상에서는 구개범거근이 횡으로 주행하여 연구개의 정중봉선(median raphe)에 부착하는 데 반해 구개열에서는 구개범거근이 전방으로 주행하여 개열 가까이에 있는 구개열 후연과 골선 개열연에 부착되어 있고 구개인두근과 구개수근이 연구개를 그냥 지나쳐직접 구개열 후연에 붙는다. 저자등은 완전 양측성 구개열을 연구개내근성형술 및 서골피판을 동반한 2개 점막성골막판을 이용한 구개성형술로 수술을 시행하여 다소의 지견을 얻었기에 문헌고찰과 함께 보고하는 바이다

• The korean journal of orthodontics
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• v.41 no.4
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• pp.237-254
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• 2011

Objective: The purpose of this study was to compare the displacement patterns shown by finite element analysis when the maxillary anterior segment was retracted from different orthodontic miniscrew positions and different lengths of lever arms in lingual continuous and segmented arch techniques. Methods: A three dimensional model was produced, the translation of teeth in both models was measured and individual displacement was calculated. Results: When traction was carried out from miniscrews in the palatal slope, lingual tipping of crowns and extrusion of the maxillary anterior segment were found in both continuous and segmented arches as the lever arms were made shorter. With miniscrews in the midpalatal suture area, the displacement patterns were similar to the palatal slope, but bodily movement of the upper incisors was observed in both continuous and segmented arches with the lever arm at 20 mm. When lever arms were longer, there was less extrusion of the incisors and more buccal displacement of the canines. Such displacement was shown less in the continuous arch than the segmented arch. The second premolar showed crown mesial tipping and intrusion, and the molars showed distal tipping in the continuous arch. The posterior segment was displaced three dimensionally in the segmented arch, but the amount of displacement was less than the continuous arch. Conclusions: It is recommended that lever arms of 20 mm in length be used for bodily movement of the anterior segment. Use of continuous or segmented arches affect the displacement patterns and induce differences in the amount of displacement.

• The korean journal of orthodontics
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• v.39 no.3
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• pp.146-158
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• 2009

Objective: The purpose of this study was to reveal the position of the incisive foramen in relation to the incisive papilla and cusp tips. Methods: Plaster models and CT images of 25 adult orthodontic patients were used to measure the width of the incisive canal and positions of the anterior and posterior borders of the incisive foramen in relation to the incisive papilla. Results: The palatal surface distance from the interdental papilla between the maxillary central incisors to the posterior border of the incisive foramen along the palatal surface was 1.7 fold of the distance from the interdental papilla between the central incisors to the posterior border of the incisive papilla. The distance between the posterior border of the incisive papilla and posterior border of the incisive foramen along the palatal surface was 6.15 ${\pm}$ 1.75 mm. The anteroposterior position of the posterior border of the incisive foramen was slightly anterior to the lingual cusp tips of the maxillary 1st premolars. The width of the incisive foramen was 4.03 ${\pm}$ 0.64 mm, therefore it is recommended to position the mini-implant more than 3 mm laterally when placing a mini-implant lateral to the incisive foramen, from the center. Conclusions: These results can be used as a reference in presuming the position of the incisive foramen when placing mini-implant in the anterior palate area.

• The korean journal of orthodontics
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• v.38 no.2
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• pp.74-82
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• 2008

Objective: This study examined the craniofacial morphology of young patients in their prepubertal stage showing class I, II malocclusion, by analyzing lateral cephalograms, and analyzed its relationship with tongue position, tongue space, and airway space in order to ascertain the effects of nasopharyngeal airway and tongue morphology on the form of the malocclusion. Methods: Seventy-six patients aging from 9 to 11 were divided into two groups depending on the ANB difference on the lateral cephalogram: Experimental group (CI II malocclusion group) showing $0{\le}ANB$ difference < 4.0; Control group (CI I malocclusion group) showing $0{\le}ANB$ difference < 4.0. The tongue space, space between palate and tongue, nasopharyngeal airway space and craniofacial morphology were compared between the two groups. Results: Tongue space, palate-tongue space, nasopharyngeal airway space showed no significant differences between class I and class II malocclusion groups. Hyperdivergent faces were associated with smaller nasopharyngeal airway space. Longer anterior facial height and posterior facial height were associated with larger tongue space, and greater anterior facial height were associated with lower tongue position. Smaller nasopharyngeal airway space showed smaller tongue space. Conclusions: Tongue space and nasopharyngeal airway space showed no significant differences between class I malocclusion group and class II malocclusion group. Only anterior facial height and posterior facial height had an influence on tongue space and nasopharyngeal airway space.

• The korean journal of orthodontics
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• v.41 no.5
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• pp.324-336
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• 2011

Objective: The aim of this study was to conduct three-dimensional finite element analysis of individual tooth displacement and stress distribution when a posterior retraction force of 200 g was applied at different positions of the retraction hook on the transpalatal arch (TPA) of a molar, and over different lengths of the lever arm on the maxillary anterior teeth in lingual orthodontics. Methods: A three-dimensional finite element model, including the entire upper dentition, periodontal ligaments, and alveolar bones, was constructed on the basis of a sample (Nissan Dental Product, Kyoto, Japan) survey of Asian adults. Individual movement of the incisal edge and root apex was estimated along the x-, y-, and z-coordinates to analyze tooth displacement and von Mises stress distribution. Results: When the length of the lever arm was 15 mm and 20 mm, the incisal edge and root apex of the anterior teeth was displaced lingually, with a maximum lingual displacement at the lever arm length of 20 mm. When the posterior retraction hook was on the root apex, the molars showed distal displacement. When the length of the lever arm was 20 mm, anterior extrusion was reduced and the crown of the canine displaced toward the buccal side, in which case, the retraction hook was on the edge, rather than at the center, of the TPA. Conclusions: The results of the analysis showed that when 6 anterior teeth were retracted posteriorly, lateral displacement of the canine and lingual displacement of the incisal edge and root apex of the anterior teeth occur without the extrusion of the anterior segment when the length of the lever arm is longer, and the posterior retraction hook is in the midpalatal area.