• Imaging Science in Dentistry
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• 제44권4호
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• pp.315-320
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• 2014

Root resorption is loss of dental hard tissue as a result of clastic activities. The dental hard tissue of permanent teeth does not normally undergo resorption, except in cases of inflammation or trauma. However, there are rare cases of tooth resorption of an unknown cause, known as "idiopathic root resorption". This report would discuss a rare case of multiple idiopathic resorption in the permanent maxillary and mandibular teeth of an otherwise healthy 36-year-old male patient. In addition to a clinical examination, the patient was imaged using conventional radiography and cone-beam computed tomography (CBCT). The examinations revealed multiple external and internal resorption of the teeth in all four quadrants of the jaws with an unknown cause. Multiple root resorption is a rare clinical phenomenon that should be examined using different radiographic modalities. Cross-sectional CBCT is useful in the diagnosis and examination of such lesions.

• 대한치과의사협회지
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• 제50권5호
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• pp.256-261
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• 2012

Temporomandibular joint (TMJ) prosthesis have been hesitated to use because of bitter memories about Proplast-Teflon interpositional TMJ implants. Many clinicians, however, are trying to use total TMJ prosthesis with getting continuous long-term follow-up results. Alloplastic total TMJ replacement have been applied to much more patients who have failed previous TMJ prostheses or TMJ implants, fibrous/bony ankylosis, severe osteoarthritis, degenerative joint disease, idiopathic condylar resorption, condyle loss by trauma or tumor resection, and other bony destructive diseases. Nowadays three types of total TMJ prosthesis are widely used. In this article, indications, types of prosthesis, safety and stability would be demonstrated with a case report.

• 대한치과기공학회지
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• 제44권3호
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• pp.89-96
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• 2022

Purpose: The purpose of this study was to investigate the types of mouthguards athletes who play contact sports use as well as their perceived discomfort of wearing them in order to analyze the relationship with wearing frequency so as acquire basic data for the development of more user-friendly mouthguards. Methods: The participants, who completed a self-report questionnaire, included 70 contact sports athletes, including high school contact (rugby and boxing) sport department affiliated athletes located in the city of Daejeon. Results: Breathing (p<0.01), fitting (p<0.05), ease of wearing (p<0.01), occlusion (p<0.05), and fatigue in muscles (p<0.05) were positively correlated with wearing frequency. Furthermore, the recognition of the mouthguards was not significantly correlated with wearing frequency. Conclusion: To prevent oral and maxillofacial trauma, multi-directional studies are imperative to develop mouthguards, which are comfortable and cost-efficient.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권3호
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• pp.189-199
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• 2006

Purpose of study: Partial thickness skin graft is the golden standard regimen for full-thickness skin defect caused by burn or trauma. However, in case of extensive burns of more than 50% of total body surface area, the donor site is not sufficient to cover all defects. As a second choice, allograft, xenograft and synthetic materials have been used to treat skin defect. Among them the amniotic membrane(AM) was used as a biological dressing for centuries because of its potential for wound healing. In this study, quantification of EGF in AM and effect of AM-collagen complex on full thickness skin defects was examined. Materials & Methods: The concentration of EGF in fresh, deep frozen and freeze-dried AM was evaluated by ELISA. EGF-R immunostaining was performed in freeze-dried AM. SD rats weighing 250${\sim}$300g was used for wound healing experiment. Three full thickness skin defects(28mm diameter) were made on dorsal surface of SD rat. The control group was covered by Vaselin gauze and AM-collagen complex and $Terudermis^{(R)}$. was grafted in two other defects. Healing area, Cinamon's score were evaluated before biopsy. Grafted sites were retrieved at 3 days, 1 week, 2 weeks and 4 weeks after operation. H & E and Factor VIII immunohistochemical stain was performed to evaluate the microscopic adhesion and structural integrity and microvessel formation. Results: 1. EGF concentration of fresh, deep frozen and freeze-dried AM showed similar level and EGF-R was stained in epithelial layer of freeze-dried AM. 2. At 4 weeks after grafting, the healing area of AM-collagen and Terudermis group was 99.29${\pm}$0.71% and 99.19${\pm}$0.77 of original size. However, that of control group was 24.88${\pm}$2.90. 3. The Cinamon's score of AM-Collagen and $Terudermis^{(R)}$. group at 4 weeks was 15.6${\pm}$1.26 and 14.6${\pm}$3.13 and that of control group was 3.7${\pm}$0.95. Significant difference was observed among control and experimental groups(p<0.05). 4. Histologic examination revealed that AM protected leukocyte infiltration and epithelial migration was nearly completed at 4 weeks. $Terudermis^{(R)}$. group showed mild neutrophil infiltration until 2 weeks and completion of epithelization at 4 weeks. Control group showed massive leukocyte infiltration until 4 weeks. 5. Microvessels were increased sharply at 1 week and control group at 1 and 4 week showed significant differences with $Terudermis^{(R)}$. group of same interval(p<0.05) but no differences were found with AM group(p<0.05). Conclusion: EGF and EGF-R were well preserved in freeze-dried AM. AM attached to collagen acted as excellent biologic dressing which had similar effect with $Terudermis^{(R)}$. AM showed anti-inflammatory action and healing was completed at 4 weeks after full-thickness skin defect.

• 대한두개안면성형외과학회지
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• 제20권3호
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• pp.212-216
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• 2019

Zygomaticomaxillary complex (ZMC) fractures account for a substantial proportion of trauma cases. The most frequent complications of maxillofacial fracture treatment are infections and soft tissue flap dehiscence. Postoperative infections nearly always resolve in response to oral antibiotics and local wound care. However, a significant infection can cause a permanent fistula. A 52-year-old man visited our clinic to treat an oroantral fistula (OAF), which was a late complication of a ZMC fracture. Postoperatively, the oral suture site dehisced, exposing the absorbable plate. However, he did not seek treatment. After 5 years, an OAF formed with a $2.0{\times}2.0cm$ bony defect on the left maxilla. We completely excised the OAF, harvested a piece of corticocancellous bone from the iliac crest, inserted the harvested bone into the defect, and covered the soft tissue defect with a buccal mucosal transposition flap. Although it is necessary to excise OAFs, the failure rate is higher for large OAFs (> 5 mm in diameter) because of the extensive defect in the underlying bone that supports the overlying flap. Inappropriate management of postoperative wounds after a ZMC fracture can lead to disastrous outcomes, as in this case. Therefore, proper postoperative treatment and follow-up are essential.

• Imaging Science in Dentistry
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• 제42권3호
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• pp.147-154
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• 2012

Purpose: This study was performed to evaluate the incidence and degree of external apical root resorption of maxillary incisors after orthodontic treatment and to evaluate particular associated factors related to external apical root resorption. Materials and Methods: The records and maxillary incisor periapical radiographs of 181 patients were investigated. Crown and root lengths were measured and compared on the pre- and post-treatment periapical radiographs. Crown length was measured from the center of the incisal edge to the midpoint of the cemento-enamel junction (CEJ). Root length was measured from the CEJ midpoint to the root apex. A correction factor for the enlargement difference was used to calculate root resorption. Results: The periapical radiographs of 564 teeth showed that the average root resorption was $1.39{\pm}1.27$ ($8.24{\pm}7.22$%) and $1.69{\pm}1.14$ mm ($10.16{\pm}6.78%$) for the maxillary central and lateral incisors, respectively. The results showed that the dilacerated or pointed roots, maxillary premolar extraction cases, and treatment duration were highly significant factors for root resorption (p<0.001). Allergic condition was a significant factor at p<0.01. Age at the start of treatment, large overjet, and history of facial trauma were also factors significantly associated with root resorption (p<0.05). There was no statistically significant difference in root resorption among the factors of gender, overbite, tongue-thrusting habit, types of malocclusion, and types of bracket. Conclusion: These results suggested that orthodontic treatment should be carefully performed in pre-treatment extraction patients who have pointed or dilacerated roots and need long treatment duration.

• 대한장애인치과학회지
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• 제6권2호
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• pp.116-119
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• 2010

Trauma to the lips and tongue can occur by accidental self-biting after dental treatment. After local anesthesia, it is likely that the patient may feel painless even in biting the tongue. In case of young children and disabled patients, the dentists should be careful not to bite the tongue. In this report, we present a case of deep lingual laceration due to biting the tongue in the course of dental treatment under general anesthesia. A 33 year-old male was transferred to our hospital to treat tongue laceration. Before 2 hour on arrival, he had received dental care under general anesthesia at a dental hospital for the disabled because of cooperation difficulty and cerebral palsy. During recovery from general anesthesia, he tried to bite his own tongue involuntary. The doctors and nurses tried to prevent the patient from being injured. Despite these efforts, massive bleeding occurred from the injured sites of the tongue. Because we could not communicate with him, we decided to evaluate the extent of the injury and treat the injured sites under general anesthesia. The laceration wound was sutured for nearly 1 hr general anesthesia. During recovery we inserted mouth prop into the oral cavity to prevent further injuries from tongue biting. After full recovery from general anesthesia he didn't try to bite his tongue. After 4 hour admission, he was discharged without other complications.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권2호
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• pp.112-126
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• 1998

In dentistry, bony defects can be formed by cyst, tumor, inflammation, trauma and surgery in maxilla and mandible. If the overlying soft tissue invades and preoccupies the jaw bony defects, regenerated bony tissue same as adjacent bone can not replace whole space of the defects, thus preventing osteogenesis from occurring. Guided bone regeneration(GBR) is based on the prevention of overlying soft tissue from entering the bony defect during the initial healing periods. E-polytetrafluoroethylene(e-PTFE) is one of an effective and widely used barrier membrane for GBR, but it has the disadvantages such as surgical removal and high price. To overcome such disadvantages of e-PTFE, many investigators have proposed various absorbable barrier membranes. Inexpensive oxidized cellulose($Surgicel^{(R)}$) membrane was shown to have potential for use as an absorbable barrier membrane for regenerative procedure and it would not require surgical removal. The purpose of this study is to investigate the absorption periods of oxidized cellulose at the implant site and usefulness as a mechanical barrier, preventing the ingrowth of the overlying soft tissue into the bony defects. Two bony defects were made in each tibia of a dog using drill and one defect covered with oxidized cellulose and the other covered with periosteum directly as control. The experimental animals were sacrificed at 1st-7th, 10th, 14th, 21th, 28th day postoperatively, Inspection of the specimens was done to evaluate gross changes. Specimens were examined histopathologically by hematoxylin-eosin and Masson's trichrome staining under light microscope. The results were as follows : 1. There was no significant differences of inflammatory reaction between the experimental and the control group. 2. The resorption of oxidized cellulose was almost completed within 14th day. 3. Histologically, bone formation in the experimental group was somewhat more than that of the control group at 10th, 14th, 21th and 28th day postoperatively. The bone forming pattern of the experimental group was more regular than that of the control group. 4. There was no evidence of soft tissue invasion into the bony defect in the experimental group. In conclusion, oxidized cellulose membrane might be used as an alternative absorbable barrier membrane to prevent overlying soft tissue invasion into the bony defects.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권4호
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• pp.679-700
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• 1996

Inferior alveolar nerve dysfunction may be the result of trauma, disease, or iatrogenic injury. Inferior alveolar nerve injury is inherent risk in endodontic therapy, orthognathic surgery of the mandible, and extraction of mandibular teeth, particularly the third molars. The sensory disturbances of inferior alveolar nerve associated with such injury have been well documented clinical problem that is commonly evaluated by several clinical sensory test including Tinels sign, Von Frey test(static light touch detection), directional discrimination, two-point discrimination, pin pressure nociceptive discrimination, and thermal test. These methods used to detect and assess inferior alveolar nerve injury have been subjective in nature, relying on the cooperation of the patients. In addition, many of these techniques are sensitive to differences in the examiners experience and skill with the particular technique. Data obtained at different times or by different examiners are therefore difficult to compare. Prior experimental studies have used electro diagnostic methods(sensory evoked potential) to objectively evaluate inferior alveolar nerve after nerve injury. This study was designed with inferior alveolar nerve of rabbit. Several types of injury including mind, moderate, severe compression and perforation with 19 gauze, 21 gauze needle and 6mm, 10mm traction were applied for taking the sesory evoked ppterntial. Latency and amplitude of injury rabbit inferior alveolar nerve were investigated with sensory evoked potential using unpaired t-test. The results were as follows : 1. Intensity of threshold (T1) was $128{\pm}16{\mu}A$ : latency, $0.87{\pm}0.07$ microsecond : amplitude, $0.4{\pm}0.1{\mu}V$ : conduction velocity, 23.3 m/s in sensory evoked potential of uninjured rabbit inferior alveolar nerve. 2. Rabbit inferior alveolar nerve consists of type II and III sensory nerve fiber. 3. Latency was increased and amplitude was decreased in compression injury. The more injured, the more changed in latency and amplitude. 4. Findings in perforation injury was similar to compression injury. Waveform for sensory evoked potential improved by increasing postinjured time. 5. Increasing latency was prominent in traction injury rabbit inferior alveolar nerve. 6. In microscopic histopathological findings, significant degeneration and disorganization of the internal architecture were seen in nerve facicle of severe compression and 10mm traction group. From the above findings, electrophysiological assessment(sensory evoked potential) of rabbit injured inferior alveolar nerve is reliable technique in diagnosis and prognosis of nerve injury.

• 대한소아치과학회지
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• 제35권1호
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• pp.175-180
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• 2008

치아 및 치조골은 복합적인 구조이므로 치아의 함입이나 측방 탈구와 같은 치조와의 변위가 있는 다수 치아를 포함한 외상에서 치조골 골절이 동반될 수 있다. 치조골이 골절되면 치주인대 및 치수로의 혈행이 단절되어 치아의 합병증을 유발할 수 있고, 특히 유치열기 외상은 후속 영구치배에 손상을 줄 가능성이 있으므로 장기간의 관찰이 필요하다. 치아 및 치조골 골절의 치료 시에는 환자의 연령과 외상의 위치 및 범위, 유치의 변위 정도 및 방향을 고려해야하며, 골절편을 재위치 시키고 고정하기 위하여 아치바(arch bar), 레진-강선 고정, 교정용 밴드, 아크릴 또는 금속 캡 스플린트(acrylic or metal cap splint), 화이버 스플린트(fiber-splint) 등의 다양한 방법이 고안되었다. 본 증례는 외상으로 인하여 치조골이 골절되어 내원한 1세 11개월 된 환아로서 모형상에서 레진-강선 오픈 캡 스플린트(resin-wire open cap splint)를 제작하여 고정한 후 양호한 치료 결과를 얻었다. 이 방법은 부가적인 기공 과정이 필요하지만, 유치열기에서 사용할 수 있고, 시술시간이 짧아 비협조적인 환아에게 진정요법 없이 적용할 수 있으며, 일반적인 아크릴 캡 스플린트에 비해 부피가 작아 불편감이 적고, 교합을 방해하지 않으며, 접착시 시멘트가 빠져나갈 공간이 있어서 스플린트의 정확한 안착이 가능하다. 또한 비교적 통증이 적으며 침습적이지 않아 출혈이 없으므로 의과적문제가 있는 경우에도 사용할 수 있다.