• The korean journal of orthodontics
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• v.51 no.4
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• pp.241-249
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• 2021

Objective: This study aimed to evaluate the volume, amount, and localization of root resorption in the maxillary first premolars using micro-computed tomography (micro-CT) after expansion with four different rapid maxillary expansion (RME) appliances. Methods: In total, 20 patients who required RME and extraction of the maxillary first premolars were recruited for this study. The patients were divided into four groups according to the appliance used: mini-implant-supported hybrid RME appliance, hyrax RME appliance, acrylic-bonded RME appliance, and full-coverage RME appliance. The same activation protocol (one activation daily) was implemented in all groups. For each group, the left and right maxillary first premolars were scanned using micro-CT, and each root were divided into six regions. Resorption craters in the six regions were analyzed using special CTAn software for direct volumetric measurements. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U test with Bonferroni adjustment. Results: The hybrid expansion appliance resulted in the lowest volume of root resorption and the smallest number of craters (p < 0.001). In terms of overall root resorption, no significant difference was found among the other groups (p > 0.05). Resorption was greater on the buccal surface than on the lingual surface in all groups except the hybrid appliance group (p < 0.05). Conclusions: The findings of this study suggest that all expansion appliances cause root resorption, with resorption craters generally concentrated on the buccal surface. However, the mini-implant-supported hybrid RME appliance causes lesser root resorption than do other conventional appliances.

• Korean Journal of Head & Neck Oncology
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• v.37 no.2
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• pp.97-100
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• 2021

Pilomatricoma(or calcifying epithelioma) is a not common benign solitary tumor originated from outer root sheath cell of hair follicle or hair follicle of sebaceous glands. The tumor usually presents as an asymptomatic, hard, superficial located, and skin colored to reddish blue cutaneous mass. Most of the tumors are less than 10mm in diameter and adherent to the skin. Recently, 48-year-old man presented with cheek mass. The tumor was 2.6cm sized and located at the subcutaneous layer of cheek on CT scan. The tumor was clearly removed via transoral approach with buccal incision leaving no wound on face. The mass was confirmed as pilomatricoma on pathologic examination. Herein, we report our experience with literature review.

• Journal of Species Research
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• v.12 no.1
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• pp.55-67
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• 2023

Two new records of marine nematodes, belonging to the family Ironidae de Man, 1876, are reported based on the specimens collected from intertidal sediments from the west coast of Korea. Conilia sinensis is characterized by a relatively long body length, a well-developed buccal cavity with three claw-like teeth, the presence of a single spicule with transverse striations, the presence of rib-shaped telamons, and single precloacal supplement. Pheronous donghaiensis is distinguished from other species of the genus by a well-developed buccal cavity with four claw-like solid teeth and minute denticles, relatively short and thick spicules with the central septum, the presence of 8-9 curved tubular-shaped precloacal supplements, and a sharp pointed tail with three small tubular supplements arranged into two rows in males. In this report, we provide a taxonomic description and illustrations of two unrecorded species of the family Ironidae by differential interference contrast microscopy. This is the first taxonomic report on the species of the family Ironidae from Korea.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.2
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• pp.91-95
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• 2023

This study examined the effects of a vertical incision on postoperative edema after third molar extraction. The study design was that of a comparative split-mouth approach. Evaluation was performed via magnetic resonance imaging (MRI). Two patients with homogeneous bilateral impacted mandibular third molars were enrolled. These patients underwent facial MRI within 24 hours after simultaneous extraction surgery. Modified triangular flap and enveloped flap incisions were made. Postoperative edema was evaluated by MRI and was assessed according to anatomical space. The two pairs of homogeneous extractions demonstrated that vertical incisions were associated qualitatively and quantitatively with extensive postoperative edema. The edema associated with these incisions spread toward the buccal space, beyond the buccinator muscle. In conclusion, a vertical incision with mandibular third molar extraction was related to edema in the buccal space and the fascial space, which contributed to clinical facial swelling.

• Journal of Dental Anesthesia and Pain Medicine
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• v.24 no.5
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• pp.319-328
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• 2024

Background: It is vital to identify more efficient anesthesia techniques for the restorative or endodontic treatment of mandibular molars. Both articaine buccal infiltration anesthesia (ABI) and lidocaine inferior alveolar nerve block anesthesia (LIANB) may not provide profound anesthesia, necessitating supplementary anesthesia. This study aimed to investigate whether lidocaine intraosseous lidocaine intraosseous anesthesia (LIO) is more suitable than ABI as primary anesthesia for caries treatment of mandibular molars. Methods: This study retrospectively analyzed patients treated for advanced caries according to the International Caries Detection and Assessment System (ICDAS) 5 and 6. The study involved 48 patients, split evenly between those receiving ABI and LIO, and examined the anesthesia success rate, pain during anesthesia, onset time, duration, and post-anesthesia lower lip numbness using Chi-square and Independent T-tests. Results: In the ABI group, 17 patients (70.8%) did not require additional anesthesia, whereas all 24 patients (100%) in the LIO group did not require additional anesthesia (P < 0.001). ABI was associated with significantly higher pain during anesthesia, slower onset time, and longer duration of anesthesia than LIO. There was no significant difference in post-anesthesia lower lip numbness between the two methods. Conclusion: Intraosseous anesthesia using lidocaine is more effective for treating severe caries in the mandibular molars because of its higher success rate, decreased pain during anesthesia, faster onset, and shorter recovery time.

• Animal Systematics, Evolution and Diversity
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• v.40 no.4
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• pp.302-307
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• 2024

Carcinothoe haustra n. gen. n. sp. feeding on eggs of the three-spotted swimming crab Portunus sanguinolentus is described from Korean waters. Choniosphaera indica Gnanamuthu, 1954, which was previously described as copepod parasitic on the same species of the crab from India, is transferred to Carcinothoe n. gen. As two significant synapomorphic features in the female of the new genus, the antennule is 5-segmented and the caudal ramus is transformed into an elongate stylet. As other diagnostic features in the female of the new genus, the body is elliptical, unsegmented, and slightly compressed laterally, the urosome is completely fused with the prosome, the caudal rami are fused with abdominal region, the genital region is positioned on the ventral surface and partly covered with a pair of genital plates, the antenna is 4-segmented with two denticulate spines distally, the maxillule bears two setae on the precoxal endite and three apical setae on the unsegmented palp, the maxilla is 2-segmented, and the maxilliped is 4-segmented and tipped with a denticulate spine. Carcinothoe haustra n. gen. n. sp. differs from C. indica n. comb. in having an anteroventrally protruded buccal region, the antennule which is remotely separated from the buccal region, and no legs.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.3
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• pp.194-201
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• 2010

Purpose: The purpose was to compare the marginal fidelity and the fracture resistance of the zirconia crowns according to the various coping designs with different thicknesses and cement types. Materials and methods: Zirconia copings were designed and fabricated with various thicknesses using the CAD/CAM system (Everest, KaVo Dental GmbH, Biberach., Germany). Eighty zirconia copings were divided into 4 groups (Group I: even 0.3 mm thickness, Group II: 0.3 mm thickness on the buccal surface and the buccal half of occlusal surface and the 0.6 mm thickness on the lingual surface and the lingual half of occlusal surface, Group III: even 0.6 mm thickness, Group IV: 0.6 mm thickness on the buccal surface and the buccal half of occlusal surface and the 1.0 mm thickness on the lingual surface and the lingual half of occlusal surface) of 20. By using a putty index, zirconia crowns with the same size and contour were fabricated. Each group was divided into two subgroups by type of cement: Cavitec$^{(R)}$ (Kerr Co, USA) and Panavia-$F^{(R)}$ (Kuraray Medical Inc, Japan). After the cementation of the crowns with a static load compressor, the marginal fidelity of the zirconia crowns were measured at margins on the buccal, lingual, mesial and distal surfaces, using a microscope of microhardness tester (Matsuzawa, MXT-70, Japan, ${\times}100$). The fracture resistance of each crown was measured using a universal testing machine (Z020, Zwick, Germany) at a crosshead speed of 1 mm/min. The results were analyzed statistically by the two-way ANOVA and oneway ANOVA and Duncan's multiple range test at $\alpha$=.05. Results: Group I and III showed the smallest marginal fidelity, while group II demonstrated the largest value in Cavitec$^{(R)}$ subgroup (P<.05). For fracture resistance, group III and IV were significantly higher than group I and II in Cavitec$^{(R)}$ subgroup (P<.05). The fracture resistances of Panavia-$F^{(R)}$ subgroup were not significantly different among the groups (P>.05). Panavia-$F^{(R)}$ subgroup showed significantly higher fracture resistance than Cavitec$^{(R)}$ subgroup in group I and II (P<.05). Conclusion: Within the limitation of this study, considering fracture resistance or marginal fidelity and esthetics, a functional ceramic substructure design of the coping with slim visible surface can be used for esthetic purposes, or a thick invisible surface to support the veneering ceramic can be used depending on the priority.

• Journal of dental hygiene science
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• v.12 no.1
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• pp.39-44
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• 2012

For the purpose of examining the dental biofilm reduction effect and control difficulty level through a dental biofilm control program in this study, the total of 131 medical records (82.9%) were used for the final analysis upon excluding the records that were not suitable for this study among the records of 158 persons for the medical records of clinical hygiene case reports that were submitted from 2006 to 2011 by students at the Department of Dental Hygiene at N University located in Chungnam region. The result of examining the dental biofilm reduction effect according to the visit number when conducting a dental biofilm control program showed that the dental biofilm index reduced meaningfully as the visit number increased. However, in the case of those that visited for 7 sessions, the level of reduction was not statistically meaningful. For the purpose of comparing the dental biofilm index mean per area of teeth during the final session visit of dental biofilm control program, the area of teeth was classified into labial/buccal surface, lingual/palatal surface and proximal surface, and the dental biofilm index of lingual/palatal surface was the highest with 26.5%. The result of measuring the dental biofilm of maxilla/mandible revealed meaningful differences between the dental biofilm index of maxilla and mandible. The result of analyzing the dental biofilm index of labial/buccal surface, lingual/palatal surface and proximal surface revealed meaingful differences among the dental biofilm index of labial/ buccal surface, lingual/palatal surface and proximal surface.

• The korean journal of orthodontics
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• v.25 no.1 s.48
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• pp.101-110
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• 1995

The purpose of this study was to observe the tissue response to the orthodontic force applied immediately after buccal horizontal subapical osteotomy of maxilla. Five mongrel cats weighing about 2.5 Kg were used for this experiment. The left upper canine and premolar of each cat served as a experimental side and the right ones as a control side. On the experimental side, a 100gm orthodontic force was applied between the upper canine and premolar immediately after the osteotomy. On the control side, the same orthodontic force was applied without the osteotomy. After 7days, the experimental animals were sacrificed. The results were as follows: 1. In the pressure zones of the experimental group, significant increase of osteoclasts and direct resolution along the alveolar bone surface was observed as compared with those of the control group. 2. In the pressure 2ones of the experimental group, a less extensive hyalinized zone was observed than those of the control group. 3. In the pressure zones of both group, no root resorption was found. 4. Tn the tension zones of the experimental group, new bone deposition increased along the alveolar bone surface as compared with those of the control group. In conclusion, the results suggest the possibility that early orthodontic treatment after orthognathic surgery may have some benefits if the stability of the repositioned segment at surgery is secured.

• Journal of Dental Rehabilitation and Applied Science
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• v.21 no.2
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• pp.153-167
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• 2005

The purpose of this study was to compare the v-shape thread with the square shape thread of fixture in the view of stress distribution pattern using finite element stress analysis. The finite element model was designed with the parallel placement of two standard fixtures(4.0 mm diameter ${\times}$ 11.5 mm length) on the region of mandibular 1st and 2nd molars. Three dimensional finite element model was created with the components of the implant and surrounding bone. This study simulated loads of 200 N at the central fossa in a axial direction (load A), 200 N at the buccal offset load that is 2 mm apart from central fossa in a axial direction (load B), 200 N at the buccal offset load that was 4 mm apart from central fossa in a axial direction (load C). These forces of load A',B',C' were applied to a $15^{\circ}$ inward oblique direction at that same site with 200 N. Von Mises stress values were recorded and compared in the supporting bone, fixture, and abutment screw. The following results have been made based on this study : 1. The highest stress concentration occurred at the cervical region of the implant fixture. 2. Von Mises stress value of off-site region was higher than that of central fossa region. 3. Square shape thread type showed more even stress distribution in the vertical and oblique force than V-shape thread type. 4. Stress distribution was the most effective in the case of buccal offset load (2, 4 mm distance from central fossa) in the square shape thread type. 5. V-shape thread type revealed higher von Mises stress value than square shape thread type in all environmental condition. The results from numerical analyses concluded that square shape thread type had the lower destructive stress and more stress distribution between the fixture and bone interface than V-shape thread type. Therefore, square shape thread type was regarded as optimal thread configuration in biomechanical concepts.