• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.300-309
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• 2001

The purpose of this study was to investigate the caries prevalence and caries pattern of preschool children in a small city. Six hundred twenty four kindergarten children in Milyang city were examined for their caries experience of individual teeth and surfaces by dmf index. The obtained results were as follows. 1. The rate of children with caries experience(dmft rate) in primary teeth was 74.0% in 3-year-olds, 83.8% in 4-year-olds, and 90.6% in 5-year-olds. The mean number of decayed, missed, and filled primary teeth(dmft index) was 3.47 in 3-year-olds, 5.41 in 4-year-olds, and 6.01 in 5-year-olds. 2. The caries prevalence of children in this study was higher than those of other researches in past and in other cities. 3. The caries-experienced teeth in order in 5-year-olds were as follows : mandibular 2nd primary molar, mandibular 1st primary molar, maxillary 2nd primary molar, maxillary primary central incisor and maxillary 1st primary molar. 4. The pattern of dental caries development was different between the incisors and molars. The prevalent surface of caries was proximal surface in primary incisors, but occlusal surface in primary molars.

• Journal of Yeungnam Medical Science
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• v.18 no.1
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• pp.112-122
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• 2001

Background: Cleft lip and palate deformity have unknown patterns of maxillofacial growth and development. The maxillofacial growth can be affected either by congenital or environmental factors such as infection and trauma. Surgical repair of cleft lip and palate may interfere the subsequent growth and development of maxillofacial region. The purpose of this study is to evaluate the characteristics of maxillofacial growth patterns in adult cleft lip and palate patients. Materials and Methods: The material for this study consisted of 17 adult male patients with cleft lip and palate. Cephalometric tracing and measurements were done by one investigator. The relationship between 17 cleft lip and palate patients and Korean norms were evaluated statistically. Results: There were statistically differences in Na. perpendicular to point A, SNA angle, effective maxillary length, maxillofacial differencial. Wit's appraisal and upper incisor to point A(p < 0.01). Pogonion to Na. perpendicular also statistically differed(p < 0.05). Other measurements didn't statistically differ. Conclusion: It was evident that in adult cleft lip and palate patients, maxilla was retruded and short. Careful cleft lip and palate repair and treatment are recommended for facilitating normal growth of maxilla.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.2
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• pp.261-273
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• 1991

This study was undertaken to document and better defined this condition to help clarify this clinical and radiographical appearances by the analysis of clinical and radiographical features of fibro-osseous lesions in the jaws. A study was made of a series of 128 cases with fibro-osseous lesions. The obtained results were as follows. 1. Fibrous dysplasia of the jaws occurred with equal predilection for males and females. But the females occurred in 68% of cemento-ossifying fibroma and 75% of periapical cemental dysplasia. 2. 43% of fibrous dysplasia and 32% of cemento-ossifying fibroma occurred in the 2nd decades and 33% of periapical cemental dysplasia in 5th decades. 3. 62% of fibrous dysplasia occurred in the maxilla, 73% of cemento-ossifying fibroma in mandible, 90% of periapical cemental dysplasia in mandible. 4. 98% of fibrous dysplasia occurred in premolar-molar region, 77% of cemento-ossifying fibroma in molar region, 68% of periapical cemental dysplasia in incisor region. 5. In serial radiographic features, mature stage were 55% of fibrous dysplasia, 45% of cemento-ossifying fibroma, 59% of periapical cemental dysplasia. 6. 87% of fibrous dysplasia had monostotic lesion, 67% of periapical cemental dysplasia had multiple lesions. 7. In fibrous dysplasia and cemento-ossifying fibroma, migration of tooth occurred in 61.7% and 36.4%, retention of tooth occurred in 4.3% and 9.1%, loss of lamina dura occurred in 6.4% and 9.1%, and root resorption had not occurred in fibrous dysplasia, but occurred in 18% of cemento-ossifying fibroma, displacement of mandibular canal occurred in 14.9% and 31.8%.

• The korean journal of orthodontics
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• v.43 no.6
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• pp.271-278
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• 2013

Objective: The purposes of this study were to determine the accuracy of crown and root length measurements of premolars using cone-beam computed tomography (CBCT) and to generate reference CBCT-based data on incisor, canine, and premolar lengths in patients with malocclusions. Methods: Imaging was performed using a CBCT scanner with a 0.292-mm voxel size and 12-bit grayscale. The CBCT-based length measurements were compared with direct measurements of 94 subsequently extracted premolars without metal restorations using the paired t-test. Furthermore, the crown and root lengths of incisors, canines, and premolars in 62 Korean patients with malocclusions were measured using CBCT, and Pearson's correlation coefficients were calculated to examine the relationship between the crown and root length measurements of each tooth type. Results: The differences between the CBCT-based and direct measurements of the extracted premolars were not significant, with 95% limits of agreement of -0.90 to 0.90 mm for crown length and -1.23 to 1.18 mm for root length. Weak positive correlations between the crown and root length measurements were observed for the mandibular canine and premolars. Conclusions: The CBCT-based measurements showed a wider range of limits of agreements for root length than for crown length. The CBCT-based data can be used as a reference for evaluating root length and resorption of teeth without metal restorations in patients with malocclusions.

• Restorative Dentistry and Endodontics
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• v.44 no.4
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• pp.39.1-39.8
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• 2019

The present report presents a case of dens invaginatus (DI) in a patient with 4 maxillary incisors. A 24-year-old female complained of swelling of the maxillary left anterior region and discoloration of the maxillary left anterior tooth. The maxillary left lateral incisor (tooth #22) showed pulp necrosis and a chronic apical abscess, and a periapical X-ray demonstrated DI on bilateral maxillary central and lateral incisors. All teeth responded to a vitality test, except tooth #22. The anatomic form of tooth #22 was similar to that of tooth #12, and both teeth had lingual pits. In addition, panoramic and periapical X-rays demonstrated root canal calcification, such as pulp stones, in the maxillary canines, first and second premolars, and the mandibular incisors, canines, and first premolars bilaterally. The patient underwent root canal treatment of tooth #22 and non-vital tooth bleaching. After a temporary filling material was removed, the invaginated mass was removed using ultrasonic tips under an operating microscope. The working length was established, and the root canal was enlarged up to #50 apical size and obturated with gutta-percha and AH 26 sealer using the continuous wave of condensation technique. Finally, non-vital bleaching was performed, and the access cavity was filled with composite resin.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.291-297
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• 2016

Patients with $Sj{\ddot{o}}gren^{\prime}s$ syndrome usually suffer from teeth discoloration and attrition due to xerostomia. If the anterior teeth are badly worn, problems such as loss of anterior guidance, occlusal disharmony, and limited space for restoration may occur. However, ideal occlusion is obtained in both centric and eccentric relation by regaining the disocclusion of the posterior teeth through the anterior and lateral guidance using twin-stage method. In this case, rehabilitation was performed for a $Sj{\ddot{o}}gren^{\prime}s$ syndrome patient with maxillary and mandibular incisor's severe attrition and teeth discoloration by using twin-stage method.

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.715-724
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• 1999

The purpose of this study was to approve the possibility of clinical application of selftesting technique to confirm the cleanness status of the tooth surface after mechanical toothbrushing. Thirty-two periodontal patients who did not compromise any other systemic diseases were divided into two groups. Control group was instructed only the Bass method for toothbrushing, and then experimental group was demonstrated the Bass method and self-testing technique respectively for plaque control during this experiment. Selftesting technique is composed the comparison of roughness of the labial surface of maxillary central incisor and other toothsurface with touch sense using the tip of tongue. Plaque score and Gingival index were measured as clinical parameters at baseline and 1, 2 and 4 weeks after scaling and root planing. The results were as follows ; 1. Plaque scores and gingival index of 1, 2, and 4 weeks of two groups were statistically significant differences when compared with baseline value (p<0.05). 2. Plaque scores and gingival index of baseline and 1 week between two groups were not significant differences (p<0.05). 3. Plaque scores and gingival index of 2 and 4 weeks of test group were statistically significant difference when compared with control group (p<0.05). From the above results, self-testing technique which decides necessity of additional toothbrushing when tongue tip of subjects touch the maxillary molar buccal surfaces and mandibular molar lingual surfaces nd compares with maxillary anterior labial surfaces after toothbrushing appeared to effect the motivation of subjects. This study suggests that self-testing technique for cleanness after toothbrushing should be effect on the maintenance of oral hygiene when it is applied to clinical practice.

• The korean journal of orthodontics
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• v.50 no.6
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• pp.373-382
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• 2020

Objective: To compare computer-aided design and computer-aided manufacturing (CAD/CAM) customized nitinol retainers with standard stainless-steel fixed retainers over a 12-month study period. Methods: This randomized controlled trial (RCT) was conducted on 62 patients randomly allocated to a control group that received stainless-steel retainers or a test group that received customized CAD/CAM nickel-titanium retainers. Four time points were defined: retainer placement (T0) and 1-month (T1), 6-month (T2), and 12-month (T3) follow-up appointments. At each time point, Little's irregularity index (LII) (primary endpoint) and dental stability measurements such as intercanine width were recorded in addition to assessment of periodontal parameters. Radiological measurements such as the incisor mandibular plane angle (IMPA) were recorded at T0 and T3. Failure events (wire integrity or debonding) were assessed at each time point. Results: From T0 to T3, LII and other dental measurements showed no significant differences between the two groups. The data for periodontal parameters remained stable over the study period, except for the gingival index, which was slightly, but significantly, higher in the test group at T3 (p = 0.039). The IMPA angle showed no intergroup difference. The two groups showed no significant difference in debonding events. Conclusions: This RCT conducted over a 12-month period demonstrated no significant difference between customized CAD/CAM nickel-titanium lingual retainers and standard stainless-steel lingual retainers in terms of dental anterior stability and retainer survival. Both retainers eventually appeared to be equally effective in maintaining periodontal health.

• Journal of Periodontal and Implant Science
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• v.46 no.2
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• pp.96-106
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• 2016

Purpose: Stress distribution and mandible distortion during lateral movements are known to be closely linked to bruxism, dental implant placement, and temporomandibular joint disorder. The present study was performed to determine stress distribution and distortion patterns of the mandible during lateral movements in Class I, II, and III relationships. Methods: Five Korean volunteers (one normal, two Class II, and two Class III occlusion cases) were selected. Finite element (FE) modeling was performed using information from cone-beam computed tomographic (CBCT) scans of the subjects' skulls, scanned images of dental casts, and incisor movement captured by an optical motion-capture system. Results: In the Class I and II cases, maximum stress load occurred at the condyle of the balancing side, but, in the Class III cases, the maximum stress was loaded on the condyle of the working side. Maximum distortion was observed on the menton at the midline in every case, regardless of loading force. The distortion was greatest in Class III cases and smallest in Class II cases. Conclusions: The stress distribution along and accompanying distortion of a mandible seems to be affected by the anteroposterior position of the mandible. Additionally, 3-D modeling of the craniofacial skeleton using CBCT and an optical laser scanner and reproduction of mandibular movement by way of the optical motion-capture technique used in this study are reliable techniques for investigating the masticatory system.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.1
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• pp.77-82
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• 2011

A long-term follow-up study of a case of impacted teeth associated with a large dentigerous cyst in the left maxilla is presented. The patient was a 30-year-old man who had a large dentigerous cyst in the premaxilla and left posterior maxilla, which impacted the canine and supernumerary tooth. This is one of the most prevalent types of odontogenic cysts associated with an erupted or developing tooth, particularly the mandibular third molars. The other teeth commonly affected in order of frequency are the maxillary canines, maxillary third molars and rarely, the central incisor. Radiographically, the cyst appears as huge ovoid well-demarcated unilocular radiolucency with a sclerotic border and causes ectopic displacement of the inferior border of the maxillary sinus without destruction. Dentigerous cysts may grow unnoticed to such extensive sizes as to occupy a considerable portion of the maxillary sinus. These cysts appear to be associated with a supernumerary tooth in the maxillary anterior incisors region called the mesiodens and impacted canine. The present case report describes the surgical enucleation of a dentigerous cyst involving the permanent maxillary left canine and mesioden. After surgery, left maxillary sinus recovered their normal size and apposition of bone was observed around the apex of the posterior teeth. During the subsequent years, there was no recurrence of the cystic lesion but the inflammation was evoked in the anterior maxilla after 42 months. This complication appeared to have correlated with bony healing in the enucleation site of the cyst. We report the healing status of a huge dentigerous cyst in the maxilla for 5 years with a review of the relevant literature.