• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권2호
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• pp.124-129
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• 2013

Multiple segment osteotomy orthognathic surgery serves to combine the total or segmental maxillary and mandibular correction of the dentofacial deformities with concurrent procedures to provide immediate repositioning to the dento-osseous elements. In addition, splitting the palate may often be necessary to correct a functionally poor relationship of the maxilla to the mandible or the facial skeleton by realigning the maxillary arch. In this case, the discrepancy in a bimaxillary horizontal relationship and the space between the 2nd premolar and 2nd molar was retained after lengthy preoperative orthodontic treatment. However, we could correct these dento-osseous discrepancies immediately by performing midpalatal expansion, anterior segmental osteotomy and symphyseal osteotomy with bimaxillary osteotomies. If the blood supply to each segment segments was maintained and primary closure of the operation site was feasible, multiple segment osteotomy was considered as a very effective technique for treating dentofacial deformities in vertical, transverse, and sagittal dimensions with differential repositioning of all segments.

• 대한치과보철학회지
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• 제36권2호
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• pp.293-301
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• 1998

The purpose of this study was to investigate the effects of load on root that was applied to edentulous area in three simulated situation, in each case the guiding planes of abutment were right vertical, 95 degrees, or 100 degrees to residual ridge. The 2-dimensional finite element method was used and the finite element model was prepared as fellows. Right mandibular 1st and 2nd molar was lost and the 2nd premolar with distal rest was used as primary abutment which had three different degrees of guiding plane. Then 150N of compressive force was applied to central fossae of the 1st and 2nd molars and von Mises stress and displacement was measured. The results were as follows; 1. Irrespective of slopes of guiding planes, the stress was concentrated on mesial side of root apex and distal side of coronal portion of root, in particular on junction with distal alveolar bone. As slopes of guiding planes were increased. stress on root and compact bone surrounding abutment was increased but no considerable effect was seen on compact bone of residual ridge. 2. Distal side of coronal portion of root limited by periodontal ligament was displaced distally and mesial side of apical portion was mesially. With slope of guiding plane increasing, the pattern of displacement was similar with one another but the quantity was increased. 3. Both abutment & alveolar bone were displaced downward and root of abutment, especially distal side of coronal portion, was displaced severely. As the guiding plane was tiffed more mesially over $90^{\circ}$, the degree of displacement was also increased.

• The Journal of Advanced Prosthodontics
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• 제4권1호
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• pp.37-42
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• 2012

PURPOSE. The influence of the modified process in the fiber-reinforced post and resin core foundation treatment on the fracture resistance and failure pattern of premolar was tested in this study. MATERIALS AND METHODS. Thirty-six human mandibular premolars were divided into 4 groups (n = 9). In group DCT, the quartz fibre post (D.T. Light-post) was cemented with resin cement (DUO-LINK) and a core foundation was formed with composite resin (LIGHT-CORE). In group DMO and DMT, resin cement (DUO-LINK) was used for post (D.T. Lightpost) cementation and core foundation; in group DMO, these procedures were performed simultaneously in one step, while DMT group was accomplished in separated two steps. In group LCT, the glass fiber post (LuxaPost) cementation and core foundation was accomplished with composite resin (LuxaCore-Dual) in separated procedures. Tooth were prepared with 2 mm ferrule and restored with nickel-chromium crowns. A static loading test was carried out and loads were applied to the buccal surface of the buccal cusp at a 45 degree inclination to the long axis of the tooth until failure occurred. The data were analyzed with MANOVA (${\alpha}$= .05). The failure pattern was observed and classified as either favorable (allowing repair) or unfavorable (not allowing repair). RESULTS. The mean fracture strength was highest in group DCT followed in descending order by groups DMO, DMT, and LCT. However, there were no significant differences in fracture strength between the groups. A higher prevalence of favorable fractures was detected in group DMT but there were no significant differences between the groups. CONCLUSION. The change of post or core foundation method does not appear to influence the fracture strength and failure patterns.

• 대한소아치과학회지
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• 제26권4호
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• pp.630-635
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• 1999

치아의 전위는 매우 드문 치아 기형의 하나로서 발생 또는 맹출중 인접한 2개의 영구치의 위치가 서로 바뀐것을 말한다. 전위는 상악과 하악 모두에서 발생 가능한데 그중에서 상악에서의 발생이 더 흔하며 상악견치는 가장 호발하는 치아이다. 상악에서는 상악 견치와 제 1 소구치와의 전위가 가장 빈도가 높고 그 다음으로 상악 견치와 측절치와의 전위가 많다. 전위는 완전 전위와 불완전 전위로 나눌수 있는데 완전 전위는 치관뿐 아니라 치근의 위치까지 전위된 경우를 말하고 불완전 전위는 치근의 위치는 정상이고 치관만 전위된 경우이다. 전위의 원인에 대하여 명확하게 밝혀진 것은 없으나 유치의 만기잔존이나 조기상실, 발생중의 전위나 정상 맹출 경로로부터의 이탈, 유치열시기의 안면외상 등이 제기되고 있고 이밖에 과잉치, odontoma 또는 odontogenic cyst, 염증성 병소 등을 그 원인으로 생각해 볼 수 있다. 본 증례는 유치열시기의 안면외상으로 인하여 상악 영구 견치와 측절치의 전위가 발생한 경우로서 치료후 전위된 위치로의 양호한 배열을 이루었다.

• 대한치과교정학회지
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• 제48권3호
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• pp.172-181
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• 2018

Objective: This study was performed to investigate buccal facial depth (BFD) changes after extraction and nonextraction orthodontic treatments in post-adolescent and adult female patients, and to explore possible influencing factors. Methods: Twelve and nine female patients were enrolled in the extraction and nonextraction groups, respectively. Changes in BFD in the defined buccal region and six transverse and two coronal measuring planes were measured after registering pretreatment and posttreatment three-dimensional facial scans. Changes in posterior dentoalveolar arch widths were also measured. Treatment duration, changes in body mass index (BMI), and cephalometric variables were compared between the groups. Results: BFD in the buccal region decreased by approximately 1.45 mm in the extraction group, but no significant change was observed in the nonextraction group. In the extraction group, the decrease in BFD was identical between the two coronal measuring planes, whereas this differed among the six transverse measuring planes. Posterior dentoalveolar arch widths decreased in the extraction group, whereas these increased at the second premolar level in the nonextraction group. The treatment duration of the extraction group was twice that of the nonextraction group. No differences were found in BMI and Frankfort horizontal-mandibular plane angle changes between the groups. BFD changes in the buccal region moderately correlated with treatment duration and dental arch width change. Conclusions: BFD decreased in adult female patients undergoing extraction, and this may be influenced by the long treatment duration and constriction of dentoalveolar arch width. However, nonextraction treatment did not significantly alter BFD.

• Restorative Dentistry and Endodontics
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• 제38권4호
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• pp.258-262
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• 2013

The restorative management of deep carious lesions and the preservation of pulp vitality of immature teeth present real challenges for dental practitioners. New tricalcium silicate cements are of interest in the treatment of such cases. This case describes the immediate management and the follow-up of an extensive carious lesion on an immature second right mandibular premolar. Following anesthesia and rubber dam isolation, the carious lesion was removed and a partial pulpotomy was performed. After obtaining hemostasis, the exposed pulp was covered with a tricalcium silicate cement (Biodentine, Septodont) and a glass ionomer cement (Fuji IX extra, GC Corp.) restoration was placed over the tricalcium silicate cement. A review appointment was arranged after seven days, where the tooth was asymptomatic with the patient reporting no pain during the intervening period. At both 3 and 6 mon follow up, it was noted that the tooth was vital, with normal responses to thermal tests. Radiographic examination of the tooth indicated dentin-bridge formation in the pulp chamber and the continuous root formation. This case report demonstrates a fast tissue response both at the pulpal and root dentin level. The use of tricalcium silicate cement should be considered as a conservative intervention in the treatment of symptomatic immature teeth.

• Imaging Science in Dentistry
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• 제46권2호
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• pp.117-125
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• 2016

Purpose: This study evaluated and compared interradicular distances and cortical bone thickness in Thai patients with Class I and Class II skeletal patterns, using cone-beam computed tomography (CBCT). Materials and Methods: Pretreatment CBCT images of 24 Thai orthodontic patients with Class I and Class II skeletal patterns were included in the study. Three measurements were chosen for investigation: the mesiodistal distance between the roots, the width of the buccolingual alveolar process, and buccal cortical bone thickness. All distances were recorded at five different levels from the cementoenamel junction (CEJ). Descriptive statistical analysis and t-tests were performed, with the significance level for all tests set at p<0.05. Results: Patients with a Class II skeletal pattern showed significantly greater maxillary mesiodistal distances (between the first and second premolars) and widths of the buccolingual alveolar process (between the first and second molars) than Class I skeletal pattern patients at 10 mm above the CEJ. The maxillary buccal cortical bone thicknesses between the second premolar and first molar at 8 mm above the CEJ in Class II patients were likewise significantly greater than in Class I patients. Patients with a Class I skeletal pattern showed significantly wider mandibular buccolingual alveolar processes than did Class II patients (between the first and second molars) at 4, 6, and 8 mm below the CEJ. Conclusion: In both the maxilla and mandible, the mesiodistal distances, the width of the buccolingual alveolar process, and buccal cortical bone thickness tended to increase from the CEJ to the apex in both Class I and Class II skeletal patterns.

• Journal of Periodontal and Implant Science
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• 제30권4호
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• pp.803-814
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• 2000

Current acceptable methods of promoting periodontal regeneration are basis of removal of diseased soft tissue, root treatment, guided tissue regeneration, graft materials, biological mediators. Platelet Rich Plasma have been reported as a biological mediator which regulate activities of wound healing progress including cell proliferation, migration, and metabolism. The purpose of this study is to evaluate the possibility of using the Platelet Rich Plasma as a regeneration promoting agent for furcation involvement defect. Five adult beagle dogs were used in this experiment. With intrasulcular and crestal incision, mucoperiosteal flap was elevated. Following decortication with 1/2 high speed round bur, degree II furcation defect was made on mandibular third(P3), forth(P4) and fifth(P5) premolar. 2 month later experimental group were PRP plus bovine bone and bovine bone only. After 4, 8 weeks, the animals were sacrificed by perfusion technique. Tissue block was excised including the tooth and prepared for light microscope with Gomori's trichrome staining. At 4 weeks after surgery, there were rapid osteogenesis phenomenon on the defected area of the Platelet Rich Plasma plus bovine bone group and early trabeculation pattern was made with new osteoid tissue produced by activated osteoblast. Bone formation was almost completed to the fornix of furcation by 4 weeks after surgery. In conclusion, Platelet Rich Plasma can promote rapid osteogenesis during early stage of periodontal tissue regeneration.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권1호
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• pp.61-68
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• 1996

1. 첫 번째 증례에서 관상 절개를 이용한 부분골 절제술과 Le Fort씨 1급 골절단술을 시행한 결과, 골절단술을 시행한 부위에 원활한 골 치유가 일어났다. 2. 두 번째 증례에서 관상 절개를 이용하여 두개안면부에 광범위한 부분골 절제술을 시행하여 만족할만한 결과를 얻었으며, 병소 부위 말초 혈관 과다는 병소의 성장에 따른 생리적 변화로 추정된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권1호
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• pp.64-67
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• 2003

본 증례는 하악골 정중부의 종창과 미맹출 매복 견치를 주소로 내원한 12세 남아 환자로 환자의 임상 및 방사선 소견상 함치성 낭종으로 가진하였다. 그러나 정확한 진단과 환자의 조절 등의 문제로 인하여 전신마취하에 낭종성 병소의 적출을 시행하여 조직 검사를 시행하였으며 그 결과 매복 견치와 관련된 점액종으로 진단되었다. 이에 저자 등은 하악 양측 견치의 미맹출 매복치과 연관되어 매우 드물게 발생되는 점액종을 경험하였기에 문헌 고찰과 함께 보고하는 바이다.