• The korean journal of orthodontics
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• v.41 no.1
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• pp.6-15
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• 2011

Objective: The aim of this study was to evaluate the biomechanical aspects of peri-implant bone upon root contact of orthodontic microimplant. Methods: Axisymmetric finite element modeling scheme was used to analyze the compressive strength of the orthodontic microimplant (Absoanchor SH1312-7, Dentos Inc., Daegu, Korea) placed into inter-radicular bone covered by 1 mm thick cortical bone, with its apical tip contacting adjacent root surface. A stepwise analysis technique was adopted to simulate the response of peri-implant bone. Areas of the bone that were subject to higher stresses than the maximum compressive strength (in case of cancellous bone) or threshold stress of 54.8MPa, which was assumed to impair the physiological remodeling of cortical bone, were removed from the FE mesh in a stepwise manner. For comparison, a control model was analyzed which simulated normal orthodontic force of 5 N at the head of the microimplant. Results: Stresses in cancellous bone were high enough to cause mechanical failure across its entire thickness. Stresses in cortical bone were more likely to cause resorptive bone remodeling than mechanical failure. The overloaded zone, initially located at the lower part of cortical plate, proliferated upward in a positive feedback mode, unaffected by stress redistribution, until the whole thickness was engaged. Conclusions: Stresses induced around a microimplant by root contact may lead to a irreversible loss of microimplant stability.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.2
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• pp.174-180
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• 2012

In case of an immature tooth with necrotic pulp, regeneration of pulp tissue into a canal would be the ideal outcome. It may be capable of promoting the continuation of normal root development. Platelet-rich fibrin has been suggested as a potentially ideal scaffold for regenerative endodontic treatment. Immature permanent teeth of young children were diagnosed with pulp necrosis and apical abscess as the result of clinical and radiographic examination. After removal of necrotic pulp, canal was irrigated with 5.25% NaOCl and dried with paper point. A triple antibiotic mixture was placed in canal space in 3 weeks. After removal of the antibiotic mixture, the platelet-rich fibrin was injected into the canal space with MTA placed directly over the platelet-rich fibrin clot. The coronal region was restored by composite resin. On the basis of short-term results of the present 3 cases, regeneration of vital tissues appears to be possible in a tooth with necrotic pulp and a periapical lesion. Also, platelet-rich fibrin proves to be potentially an ideal scaffold for this procedure. Therefore, long-term clinical observation and examination about this treatment using platelet-rich fibrin in immature permanent teeth of young children are considered to be necessary.

• The Journal of the Korean dental association
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• v.48 no.2
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• pp.140-145
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• 2010

True vertical root fracture (VRF) in nonendodontically treated teeth confined to the root surface (fatigue root fracture; FRF) is apparently uncommon, the few documented reports being Chinese. The aim of this study is to analyze the cases of a fatigue root fracture and to find out the characteristic features of teeth with a FRF. A total of 21 consecutive cases of fatigue root fracture occurring in 16 patients were reviewed. In terms of the occlusion, the presence of restorations, the location, the age and gender, each tooth and patient were analyzed. The prevalent age was in those over 50 years of age (75%) and FRFs were more frequent in male patients (69%). Fatigue root fractures occurred most frequently in the mandibular molars (61.9%; 42.9% in first molar, 19% in second molar). Fatigue root fractures were observed most frequently in the teeth with no restorations (85.7%) and in the patients with occlusal problems (94%). FRFs seem to occur frequently and may represent an undiagnosed clinical entity deserving of our attention.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.3
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• pp.191-197
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• 2012

Esthetics is important in restoring maxillary anterior area. Alveolar bone resorption and loss of interdental papilla may be minimized by immediate implantation. Previous studies showed successful results with the immediate implantation in healthy extraction socket, while many of these studies objected the immediate implantation into extraction sites with periapical lesions. Recent studies, however, reported successful results of the immediate implantation into extraction sites with periapical lesions with careful debridement of extraction sockets and general medication of antibiotics prior to implantation. A 73-year-old female visited the department of Prosthodontics in ${\bigcirc}{\bigcirc}$ University Dental Hospital with the chief complaint of fallen post-core and crown on left maxillary incisor. Although the incisor was with vertical root fracture and periapical lesion, the immediate implantation following the extraction of tooth was planned. Thorough socket debridement, irrigation with chlorhexidine, and tetracycline soaking were followed by immediate implantation. The general medication of antibiotics (Moxicle Tab.$^{(R)}$, 375 mg) was prescribed before and after the surgery. Immediate provisional restoration was delivered two days after the surgery, and the definitive metal-ceramic restoration was placed about six months later after reproducing the emergence profile from the provisional restoration. This case presents satisfying result esthetically and functionally upto two years after the placement of prosthesis with the harmonious gingival line and no loss of marginal bone.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.4
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• pp.418-425
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• 2013

This case report describes about recurrent herpetic stomatitis mimicking post-root resection complication. A 49 year-old male patient was diagnosed vertical root fracture of the mesiobuccal root of his left maxillary first molar (#26). The mesiobuccal root was resected following root canal treatment of the same tooth. 19 months later, the patient presented with pain on left hard palate after a barbecue party. Intra oral examination revealed a gum boil-like blister at the hard palate corresponding to the apex of the palatal root of #26. On clinical examination, there was bleeding on probing and the periodontal pocket depth was measured less than 5 mm with no tooth mobility. On a periapical radiograph, periodontal ligament space widening was observed. Tracing the sinus tract with gutta percha cone was attempted, however, it was impossible. Extending the field of vision, small multiple round ulcerations were observed at the palate front which caused pain to the patient. Therefore, the pain was considered a non odontogenic and the patient was referred to the department of oral medicine. The patient was diagnosed recurrent herpetic stomatitis and after 3 days of antiviral medication, the pain and ulceration were subsided.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.654-659
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• 2003

Intrusive luxation that takes approximately three percent of permanent teeth commonly occures at anterior teeth. This intrusion frequently leads to pulp necrosis, root resorption, marginal bone loss and these complications are influenced by depth of intrusion and stage of root development. Various treatment approaches have been suggested to manage of intrusive luxation. Techniques aiming to reposition the intruded tooth include an observation for spontaneous re-eruption, surgical or orthodontic repositioning. We report two cases with clinically satisfactory results for traumatically intruded maxillary central incisor. In one case which has a large open apex and mild intrusion depth, we observed for spontaneous eruption and then repositioning by forced eruption method. In other case, which has been completely intruded, was repositioned by surgical extrusion and followed by apexification.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.1
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• pp.66-72
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• 2012

Autogenous tooth transplantation can be defined as the surgical movement of a tooth from one position in the mouth to another in the same individual. The most common reasons for tooth transplantation include replacement of a missing first molar, transplantation of impacted canines to their normal positions in the arch, and transplantation of premolars in areas of missing teeth, especially in the anterior area of the mouth. The key to successful tooth transplantation is proper selection of graft with adequate root development as well as the design of surgical operation. Root development stage with half to three-quarter-developed roots increase the success rate of autotransplantation. We report the cases of successful autotransplantation which resulted in ideal healing of periodontal ligament, gingiva and alveolar bone. All transplanted teeth presented immature root formation at the moment of the procedure. After surgical procedure, we can observe good healing pattern without endodontic problem.

• The Journal of the Korean dental association
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• v.48 no.10
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• pp.754-761
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• 2010

Horizontal root fractures are defined as those that involve cementum, dentin and pulp, comprising from 0.5 to 7% of injuries in permanent dentition on dental trauma. Diagnosis is made through clinical findings and radiographic exams, the latter frequently being limited by the position of the fracture line. Treatment varies according to the displacement of crown portion and vitality of the fragments. Authors describe clinical cases of maxillary right central incisor with horizontal root fractures in dental clinic, Jeju National University Hospital.

• The Journal of the Korean dental association
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• v.57 no.11
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• pp.679-688
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• 2019

A 8-year-old patient presented with a crown-root fracture of the maxillary right central incisor with an oblique subgingival fracture line. A multidisciplinary treatment approach including endodontic treatment, surgical extraction and intraalveolar repositioning was used to gain sufficient crown length of the fractured maxillary incisor. The coronally repositioned maxillary right central incisor was stabilized by a resin wire splint. Apexification using MTA was performed. Resin core and direct resin restoration(Cl IV) on fractured teeth was built up. Clinical and radiographic follow-up of the maxillary right central incisor after 36 months showed no signs of root resorption or pathology and acceptable aesthetics and functions were maintained. Surgical extrusion can be considered as a good treatment modality for young patients.

• The Korean Journal of Oral and Maxillofacial Pathology
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• v.42 no.5
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• pp.153-158
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• 2018

Complicated crown-root fractures are considered rare occurrences in young permanent dentition; however, they often present complicated and unpredictable treatment options. The most common treatment option for crown-root fractured teeth is reattachment of fractured segment, but if it is thought impossible to maintain, it should be extracted. However, when unfavorable crown-root fracture occurs in the adolescents, extraction of fractured teeth is expected to be poor due to excessive resorption of alveolar and prosthetic replacement cannot be performed immediately, various treatment options should be considered. This report suggests root submergence in the complex crown-root fracture in growing patients is performed and the functional and aesthetic results including preservation of the alveolar bone are obtained.