• Restorative Dentistry and Endodontics
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• v.32 no.6
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• pp.483-490
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• 2007

This report describes clinical cases of a palato-gingival groove on a maxillary lateral incisor with associated localized periodontal disease and pulp necrosis. The tooth of the first case was extracted because of severe bone destruction. The palato-gingival groove of the second case was eliminated using a round bur, and the resulting defect was filled with synthetic graft and covered by an absorbable membrane. Both diagnosis and treatment of palato-gingival groove were very difficult and usually extraction of the involved tooth is the treatment of choice. but combined endodontic-peri-odontic treatment allowed the tooth to be saved.

• The korean journal of orthodontics
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• v.28 no.3 s.68
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• pp.431-440
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• 1998

While periodontal disease results in the extrusion of upper incisors with interdental spacing in adult patient, the intrusive movement should be executed for the rehabilitation in terms of esthetics and function. The present study was peformed to investigate the periodontal response following orthodontic intrusion of teeth with infrabony pocket. Bone defect and periodontal disease were produced adjacent to the both maxillary second lateral incisors in four adult dogs. Four weeks later, a flap operation was performed to eliminate inflammation and a reference notch was made on the root surface at the level of bottom of each defect. Two weeks after periodontal surgery, 4 weeks of intrusion and subsequent another 4 weeks of retention was executed on the right side of incisors while left incisors served as the control. Through the histologic analysis, following results were obtained. 1. Histologic section of control side showed the reduction of pocket depth after flap operation. However, the status of long junctional epithelium was observed while new connective tissue attachment occurred in a small area adjacent newly formed cementum 2. Epithelial attachment was less around the intruded incisor while new connective tissue attachment was much more compared to the control side. 3. Plenty of cells were observed in the connective tissue around the reference notch of the intruded incisor and the degree of the new cementum formation was higher in the intruded incisor than the control. The results of the present study suggested that an orthodontic intrusion of periodontally involved and extruded incisors could be carried out with a desirable periodontal response, provided that inflammation is under control.

• The korean journal of orthodontics
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• v.52 no.2
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• pp.150-160
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• 2022

Objective: To provide reliable prediction models based on dentoskeletal and soft tissue variables for customizing maxillary incisor positions and to optimize digitalized orthodontic treatment planning. Methods: This study included 244 Chinese women (age, 18-40 years old) with esthetic profiles after orthodontic treatment with fixed appliances (133 in group I: 1° ≤ The angle between the nasion [N]-A point [A] plane and the N-B point [B] plane [ANB] ≤ 4°; 111 in group II: 4° < ANB ≤ 7°). Dental, skeletal, and soft tissue measurements were performed on lateral cephalograms of the participants. Correlation and multiple linear regression analyses were used to determine the influence of dentoskeletal and soft tissue variables on maxillary incisor position. Results: The ideal anteroposterior position of the maxillary incisor varied between sagittal skeletal patterns. The position of the maxillary incisor correlated with the sagittal discrepancy between the maxilla and the mandible (ANB), protrusion of the midface, nasal tip projection, development of the chin, and inclination of both the maxillary and mandibular incisors. Distance from the maxillary central incisor to nasion-pogonion plane predicted using multiple linear regression analysis was accurate and could be a practical measurement in orthodontic treatment planning. Conclusions: Instead of using an average value or norm, orthodontists should customize a patient's ideal maxillary incisor position using dentoskeletal and soft tissue evaluations.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.2
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• pp.213-230
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• 2008

The aim of this study was to analyze the initial movement and the stress distribution of each tooth and periodontal ligament during the lingual lever-arm retraction of 6 maxillary incisors using FEA. Two kinds of finite element models were produced: 2-properties model (simple model) and 24-properties model (multi model) according to the material property assignment. The subject was an adult male of 23 years old. The DICOM images through the CT of the patient were converted into the 3D image model of a skull using the Mimics (version 10.11, Materialise's interactive Medical Image Control System, Materialise, Belgium). After series of calculating, remeshing, exporting, importing process and volume mesh process was performed, FEA models were produced. FEA models are consisted of maxilla, maxillary central incisor, lateral incisor, canine, periodontal ligaments and lingual traction arm. The boundary conditions fixed the movements of posterior, sagittal and upper part of the model to the directions of X, Y, Z axis respectively. The model was set to be symmetrical to X axis. Through the center of resistance of maxilla complex, a retraction force of 200g was applied horizontally to the occlusal plane. Under this conditions, the initial movements and stress distributions were evaluated by 3D FEA. In the result, the amount of posterior movement was larger in the multi model than in the simple model as well as the amount of vertically rotation. The pattern of the posterior movement in the central incisors and lateral incisors was controlled tipping movement, and the amount was larger than in the canine. But the amount of root movement of the canine was larger than others. The incisor rotated downwardly and the canines upwardly around contact points of lateral incisor and canine in the both models. The values of stress are similar in the both simple and multi model.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.574-578
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• 2002

Mesiodens is developmental tooth anomaly which is commonly found in clinical pediatric dentistry. however, it may cause many partial problem in tooth alignment when congenitally missing teeth was accompanied by mesiodens. The terms, concomitant hypodontia and hyperdontia' and oligo-pleiodontia' have been used to describe the condition in witch developmental absence of teeth and supernumerary teeth are present in the same individual. Only a few case reports of this rare condition which is opposite developmental phenomena exist in the literature. The purpose of this study is survey of congenitally missing teeth in mesiodens case and to compare previous literature of congenitally missing teeth in normal. The subjects were 310 children(247 male and 63 female) at the age from 5 to 12 years visiting the Department of Pediatric Dentistry, Pusan National University Hospital with mesiodens for last 3 years. With their pantomograms we studied congenitally missing teeth except permanent 3rd molar. 1. The preference of congenitally missing teeth in mesiodens cases was revealed to be 17.1%(53 out of 310 in total), and there was a higher prevalence in females(22.2%) than in males(15.8%). 2. The most frequently missing teeth were maxillary lateral incisors(22.7%) and mandibular second premolars(22.7%), followed by maxillary second premolar(17.3%), and mandibular lateral incisors(16.0%). There was no significant differences between maxilla(49.3%) and mandible(50.7%). 3. In number of congenitally missing teeth per person, 69.9% had one missing tooth, 22.7% had two missing teeth and 9.4% had three missing teeth.

• Journal of Periodontal and Implant Science
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• v.45 no.5
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• pp.162-168
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• 2015

Purpose: The aim of this study was to analyze the anatomical dimensions of the buccal bone walls of the aesthetic maxillary region for immediate implant placement, based upon cone-beam computed tomography (CBCT) scans in a sample of adult patients. Methods: Two calibrated examiners analyzed a sample of 50 CBCT scans, performing morphometric analyses of both incisors and canines on the left and right sides. Subsequently, in the sagittal view, a line was traced through the major axis of the selected tooth. Then, a second line (E) was traced from the buccal to the palatal wall at the level of the observed bone ridges. The heights of the buccal and palatal bone ridges were determined at the major axis of the tooth. The buccal bone thickness was measured across five lines. The first was at the level of line E. The second was at the most apical point of the tooth, and the other three lines were equidistant between the apical and the cervical lines, and parallel to them. Statistical analysis was performed with a significance level of $P{\leq}0.05$ for the bone thickness means and standard deviations per tooth and patient for the five lines at varying depths. Results: The means of the buccal wall thicknesses in the central incisors, lateral incisors and canines were $1.14{\pm}0.65mm$, $0.95{\pm}0.67mm$ and $1.15{\pm}0.68mm$, respectively. Additionally, only on the left side were significant differences in some measurements of buccal bone thickness observed according to age and gender. However, age and gender did not show significant differences in heights between the palatal and buccal plates. In a few cases, the buccal wall had a greater height than the palatal wall. Conclusions: Less than 10% of sites showed more than a 2-mm thickness of the buccal bone wall, with the exception of the central incisor region, wherein 14.4% of cases were ${\geq}2mm$.

• The korean journal of orthodontics
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• v.42 no.6
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• pp.280-290
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• 2012

Objective: This study aimed to compare the effects of conventional and orthodontic mini-implant (OMI) anchorage on tooth movement and arch-dimension changes in the maxillary dentition in Class II division 1 (CII div.1) patients. Methods: CII div.1 patients treated with extraction of the maxillary first and mandibular second premolars and sliding mechanics were allotted to conventional anchorage group (CA, n = 12) or OMI anchorage group (OA, n = 12). Pre- and post-treatment three-dimensional virtual maxillary models were superimposed using the best-fit method. Linear, angular, and arch-dimension variables were measured with software program. Mann-Whitney U-test and Wilcoxon signed-rank test were performed for statistical analysis. Results: Compared to the CA group, the OMI group showed more backward movement of the maxillary central and lateral incisors and canine (MXCI, MXLI, MXC, respectively; 1.6 mm, p < 0.001; 0.9 mm, p < 0.05; 1.2 mm, p < 0.001); more intrusion of the MXCI and MXC (1.3 mm, 0.5 mm, all p < 0.01); less forward movement of the maxillary second premolar, first, and second molars (MXP2, MXM1, MXM2, respectively; all 1.0 mm, all p < 0.05); less contraction of the MXP2 and MXM1 (0.7 mm, p < 0.05; 0.9 mm, p < 0.001); less mesial-in rotation of the MXM1 and MXM2 ($2.6^{\circ}$, $2.5^{\circ}$, all p < 0.05); and less decrease of the inter-MXP2, MXM1, and MXM2 widths (1.8 mm, 1.5 mm, 2.0 mm, all p < 0.05). Conclusions: In treatment of CII div.1 malocclusion, OA provided better anchorage and less arch-dimension change in the maxillary posterior teeth than CA during en-masse retraction of the maxillary anterior teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.317-322
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• 1999

Dens invaginatus is a developmental anomaly resulting from an invagination of the enamel organ. The incidence is highest with maxillary permanent lateral incisors. The reported occurrence ranges from 0.04 to 10%. This anomaly may involve the pulp and periapical tissues and cause pulpal inflammation, loss of vitality, apical and lateral periodontitis, periapical abscesses and cysts and stimulate internal resorption. Oehlers describes dens invaginatus as occurrence in three forms. In treating type 3 invaginatus, treatment strategy can be determined by considering the complexity and accessibility of invagination. In this case, showing simple invagination, it could be treated by simple endodontic treament confining to invagination without loss of vitality of tooth. After treatment of the present case, the results were as follows: 1. In type 3 dens invagiantus, if the tooth is vital and there is no evidence of communicating between invagination and pulp, we can save the vitality of the tooth and resolve the lesion by endodontic treament confining to the invagination. 2. In the invagination with opened apex, the closure of apex can be induced by apexification procedure doing this, we can avoid the neccessity of surgical intervention.

• The korean journal of orthodontics
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• v.32 no.2 s.91
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• pp.91-105
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• 2002

In general, orthodontists make problem lists and treatment plans based on norms of several cephalometric standards. But consideration of dentoalveolar compensation, which tends to maintain normal dental arch relationship in various skeletal jaw relationships, helps orthodontists make more individualized treatment objectives and plans. The purpose of this study was to classify skeletal patterns of normal occlusion samples by cluster analysis and to investigate the dentoalveolar compensation according to skeletal patterns. The subjects were consisted of 125 subjects who were normal occlusion samples at Seoul National University Dental Hospital, Department of Orthodontics. Lateral cephalograms in centric occlusion were traced and digitized. The skeletal patterns of normal occlusion samples were classified into three horizontal groups and three vertical groups by cluster analysis and ANOVA on the skeletal and dentoalveolar measurements among the groups were carried out. The results were as follows ; 1. Anteroposterior and vertical skeletal relationships of normal occlusion samples were very variable. 2. As the mandibular position was anterior to the maxilla, the maxillary incisors inclined more labially, the mandibular incisors more lingually, and the occlusal plane was flattened due to the anteroposterior dentoalveolar compensation. dentoalveolar height was decreased and upper posterior teeth was uprighted to the palatal plane and lower incisors and lower posterior teeth to the mandibular plane. 4. Lower incisors were more strongly associated with the dentoalveolar compensation than upper incisors according to the anteroposterior and vertical skeletal relationship.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.147-156
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• 1999

Skeletal Cl III malocclusion is an orthopedic appliance mainly used for growing children with maxillary undergrowth, which largely entails skeletal Cl III malocclusion. It improves anterior crossbite and maxillary position and thus, enables patients to attain favorable Profile but often involves unfavorable profile with protrusive upper and lower lips. Therefore, if orthodontists have knowledge of which condition helps obtain favorable occlusion and profile, they are able to predict the prognosis and limitation of the treatment. This study was done in order to help obtain favorable Profile after treating growing skeletal Cl III children. In the study, we classified childern into two groups, the one with favorable profile(Group 1, n=12) and the other with unfavorable profile(Group 2, n=14) and, with retrospective study using pre- and post-treatment lateral cephalogram, drew the following conclusions. 1. As patients had more serious labioversion of upper incisors, they were more unlikely to have favorable profiles after the treatment. Protrusion of prosthion, which was related with maxillary incisors, also affected profiles. 2. As the NL-ML angle before the treatment was small, it was more likely to get favorable profile. 3. As the degree of lower lip protrusion was high, it was likely to have bialveolar protrusion after the treatment. 4. As the degree of downward and backward rotation of mandible was high, it was likely to get unfavorable profile.