• The korean journal of orthodontics
• /
• v.23 no.1 s.40
• /
• pp.57-74
• /
• 1993

Anterior crossbite is a common malocclusion in the early deciduous dentition. Even today, many these malocclusion patients are not treated until the mixed or permanent dentition. And the purpose here is to emphasize the need for early diagnosis and possible treatment for these anterior crossbite malocclusions and their associated facial patterns. Case histories of 4 patients selected from the author's practice are presented. Different methods of treatment are evaluated. Some improvement was achieved in all patients from an early interceptive regimen, although ultimately corrective orthodontic treatment may still be needed in some. It is concluded that early interception of deciduous anterior crossbite malocclusion should by attempted in patients ; there should be no delemma in reaching such a decision. And it is essential for diagnosis and treatment to determine exact variations in growth when some appliance are used, it is recommended that growth-related records be made as early as possible.

• The korean journal of orthodontics
• /
• v.47 no.1
• /
• pp.21-30
• /
• 2017

Objective: The aim of this study was to investigate the three-dimensional (3D) position of the center of resistance of 4 mandibular anterior teeth, 6 mandibular anterior teeth, and the complete mandibular dentition by using 3D finite-element analysis. Methods: Finite-element models included the complete mandibular dentition, periodontal ligament, and alveolar bone. The crowns of teeth in each group were fixed with buccal and lingual arch wires and lingual splint wires to minimize individual tooth movement and to evenly disperse the forces onto the teeth. Each group of teeth was subdivided into 0.5-mm intervals horizontally and vertically, and a force of 200 g was applied on each group. The center of resistance was defined as the point where the applied force induced parallel movement. Results: The center of resistance of the 4 mandibular anterior teeth group was 13.0 mm apical and 6.0 mm posterior, that of the 6 mandibular anterior teeth group was 13.5 mm apical and 8.5 mm posterior, and that of the complete mandibular dentition group was 13.5 mm apical and 25.0 mm posterior to the incisal edge of the mandibular central incisors. Conclusions: Finite-element analysis was useful in determining the 3D position of the center of resistance of the 4 mandibular anterior teeth group, 6 mandibular anterior teeth group, and complete mandibular dentition group.

• Journal of Periodontal and Implant Science
• /
• v.23 no.2
• /
• pp.331-344
• /
• 1993

The purpose of this study was to investigate the change of tooth mobility and bite force according to periodontal disease severity. Tooth mobility and biting force due to change of viscoelastic property of periodontium were influenced by inflammation of periodontal tissue. 30 patients participated in this study, the periodontal disease severity is evaluated with SBI and attachment loss. SBI and attachment loss were examined by periodontal probe. Tooth mobility was tested two times to each tooth using periotest (Siemens Co, Germany) and bite force was evaluated with MPM-3000 (Nihon Kohden Co, Japan). Statistical analysis was applied to correlation ($r^2$) and regression analysis. The obtained results were as follows : 1. As the attachment loss increased, tooth mobility increased with significance, and they had highly positive correlation ($r^2=0.68$) on entire dentition. 2. As the SBI increased, tooth mobility increased with significance, and they had positive correlation ($r^2=0.37$) on entire dentition. 3. As the attachment loss increased, bite force decreased with significance, and they had highly negative correlation ($r^2=0.42$) on maxillary anterior dentition but low negative correlation ($r^2=0.20$) on the other portion of dentition. 4. As the SBI increased, bite force decreased with significance, and they had highly negative correlation ($r^2=0.31$) on maxillary anterior dentition but low negative correlation ($r^2=0.16$) on the other portion of dentition. 5. As tooth mobility increased, bite force decreased with significance, and they had highly negative correlation ($r^2=0.32$) on maxillary anterior dentition but low negative correlation ($r^2=0.16$) on the other portion of dentition.

• Imaging Science in Dentistry
• /
• v.48 no.4
• /
• pp.261-268
• /
• 2018

Purpose: To determine the impact of an image processing technique on diagnostic accuracy of digital panoramic radiographs for the assessment of anatomical structures in paediatric patients with mixed dentition. Materials and Methods: The study consisted of 50 digital panoramic radiographs of children aged from 6 to 12 years, which were later on processed using a dedicated image processing method. A modified clinical image quality evaluation chart was used to evaluate the diagnostic accuracy of anatomical structures in maxillary and mandibular anterior and maxillary premolar region of processed images. Results: A statistically significant difference was observed between pre and post-processed evaluation of anatomical structures(P<0.05) in the maxillary and mandibular anterior region. The anterior region was found to be more accurate in post-processed images. No significant difference was observed in the maxillary premolar region (P>0.05). The Inter-observer and intra-observer reliability of both pre and post processed images were excellent (>0.82) for anterior region and good (>0.63) for premolar region. Conclusion: The application of image processing technique in digital panoramic radiography can be considered a reliable method for improving the quality of anatomical structures in paediatric patients with mixed dentition.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.33 no.4
• /
• pp.278-283
• /
• 2017

Purpose: The aim of this study was to evaluate the interdental distances of anterior, premolar, and molar teeth at the cementoenamel junction (CEJ) and 2 mm below the CEJ in healthy natural dentition with cone-beam computerized tomography (cone-beam CT) in order to provide valuable data for ideal implant positioning relative to mesiodistal bone dimensions. Materials and Methods: Two hundred patients who visited Dental Hospital, Wonkwang University, who had natural dentition with healthy interdental papillae, and who underwent cone-beam CT were selected. The cone-beam CT images were converted to digital imaging and communication in medicine (DICOM) files and reconstructed in three-dimensional images. To standardize the cone-beam CT images, head reorientation was performed. All of the measurements were determined on the reconstructed panoramic images by three professionally trained dentists. Results: At the CEJ, the mean maxillary interdental distances were 1.84 mm (anterior teeth), 2.07 mm (premolar), and 2.08 mm (molar), and the mean mandibular interproximal distances were 1.55 mm (anterior teeth), 2.20 mm (premolar), and 2.36 mm (molar). At 2mm below the CEJ, the mean maxillary interdental distances were 2.19 mm (anterior teeth), 2.51 mm (premolar), and 2.60 mm (molar), and the mean mandibular interproximal distances were 1.86 mm (anterior teeth), 2.53 mm (premolar), and 3.01 mm (molar). Conclusion: The interdental distances in the natural dentition were larger at the posterior teeth than at the anterior teeth and also at 2 mm below the CEJ level compared with at the CEJ level. The distances between mandibular incisors were the narrowest and the distances between mandibular molars were the widest in the entire dentition.

• The korean journal of orthodontics
• /
• v.39 no.2
• /
• pp.83-94
• /
• 2009

Objective: The aim of this study was to investigate the 3-dimensional position of the center of resistance of the 4 maxillary anterior teeth, 6 maxillary anterior teeth, and the full maxillary dentition using 3-dimensional finite element analysis. Methods: Finite element models included the whole upper dentition, periodontal ligament, and alveolar bone. The crowns of the teeth in each group were fixed with buccal and lingual arch wires and lingual splint wires to minimize individual tooth movement and to evenly disperse the forces to the teeth. A force of 100 g or 200 g was applied to the wire beam extended from the incisal edge of the upper central incisor, and displacement of teeth was evaluated. The center of resistance was defined as the point where the applied force induced parallel movement. Results: The results of study showed that the center of resistance of the 4 maxillary anterior teeth group, the 6 maxillary anterior teeth group, and the full maxillary dentition group were at 13.5 mm apical and 12.0 mm posterior, 13.5 mm apical and 14.0 mm posterior, and 11.0 mm apical and 26.5 mm posterior to the incisal edge of the upper central incisor, respectively. Conclusions: It is thought that the results from this finite element models will improve the efficiency of orthodontic treatment.

• Journal of Oral Medicine and Pain
• /
• v.9 no.1
• /
• pp.157-167
• /
• 1984

A human bite-mark shows special feature according to the suspect's dentition. The teeth which most frequently give useful bite-marks are six upper and lower anteriors, while the premolar teeth somtimes give marks it is often difficult to distinguish. The author tried to classify and to analize the anterior dentition which makes the bite-mark directly by means of 672 maxillary and 691 mandibular stone model taken from Korean adult aging from 17 to 40 years old. The results were as follows : 1. There was no particular correlation between the presence of six normal-shaped and correctly positioned upper and lower anteriors and the presence of rotation of teeth. 2. Inter central incisor, inter lateral incisor, inter canine width and angles of adjecent teeth were not identical eath other in studied models. 3. The results of this analysis supported the statement that any bite-mark had no same feature.

• The korean journal of orthodontics
• /
• v.9 no.1
• /
• pp.67-84
• /
• 1979

The author measured the right and left craniofacial skeleton using posteroanterior cephalography of 124 male and 97 female subjects of ages ranging 2-6 years, 7-13 years and adult group on Korean. Statstical parameters were calculated by computer from the data. The results of the study were as follows. 1. In the male and female group of deciduous dentition, the right side measurements were slightly greater than the left side measurements, and generally male measurements were greater than female measurements. 2. In the both sex group of mixed dentition, the right side measurements were greater than the left side measurements, and in comparision of sex, the female recognized more growth, and development than male, especially on the cranial base, lateral maxilla, lower maxilla and dental region. 3. In the permanent dentition group, regardless of sex, the right side measurements were greater than the left side measurements, and in the sex difference, male was conspicuously greater than female on both sides measurements. 4. In the permanent dentition group, the asymmetry of the face was striking than deciduous dentition and mixed dentition group.

• Journal of the Korean Academy of Esthetic Dentistry
• /
• v.8 no.1
• /
• pp.18-27
• /
• 1999

A tooth solely can not be an exclusive factor to attain our goal, esthetics. Other consideration, such a proportion of individual tooth, harmonized arrangement of the dentition and surrounding tissues including gingiva, lip and face should be taken into account. Esthetic gingival pattern and incisal level in the anterior area are the very important factors for esthetic restoration of the smile. We often propose adequate periodontal and prosthodontic approaches in order to improve the esthetics of the anterior area. Here, I would like to share some cases which include soft tissue management for ovate pontic placement, osteoplasty, resin filling for severe cervical caries, and bleaching approach to discolored root caused by endodontic treatment, and so on.

• The korean journal of orthodontics
• /
• v.43 no.3
• /
• pp.147-158
• /
• 2013

This article describes the orthodontic treatment of a 31-year-old Korean female patient with gummy smile and crowding. The patient showed excessive gingival display in both the anterior and posterior areas and a large difference in gingival heights between the anterior and posterior teeth in the maxilla. To correct the gummy smile, we elected to intrude the entire maxillary dentition instead of focusing only on the maxillary anterior teeth. Alignment and leveling were performed, and a midpalatal absolute anchorage system as well as a modified lingual arch was designed to achieve posterosuperior movement of the entire upper dentition. The active treatment period was 18 months. The gummy smile and crowding were corrected, and the results were stable at 21 months post-treatment.