• 대한소아치과학회지
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• 제37권1호
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• pp.109-116
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• 2010

매복은 임상 검사나 방사선 사진 검사 상에서 인식 가능한 맹출 경로 상에 장애물이나 이소 위치에 의한 치아 맹출의 정지를 의미한다. 상악 중절치의 치아 매복의 원인으로는 과잉치, 치아종, 치배의 이소위치, 외상 후 연조직 치유에 의한 폐쇄, 만곡치, 정지된 치근 발육 등이 있다. 매복된 치아는 인접치의 근심이동으로 인한 공간 상실, 부정교합, 인접치의 치근 흡수, 낭종의 형성 등을 유발할 수 있으므로 맹출장애에 대한 주의 깊은 관찰과 조기 진단이 중요하며 적절한 치료가 시행되어야 한다. 매복된 치아의 치료방법으로는 유치의 발거나 외과적 노출을 통한 맹출 유도, 경과관찰, 외과적 방법이나 교정력을 이용한 매복치의 재위치, 매복치의 외과적 발거 등이 있다. 이 중 교정적 견인은 매복된 치아가 원인을 제거한 후 또는 외과적으로 치관을 노출시킨 후에 일정기간의 관찰에도 맹출하지 않거나, 맹출경로가 정상에서 많이 벗어나 맹출이 기대되지 않을 경우 적용될 수 있다. 본 증례는 매복된 상악중절치를 교정적 견인을 통해 정상적인 맹출 방향으로 유도한 치험례들로 양호한 치료 결과를 보였기에 이를 보고하고자 하는 바이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.2.1-2.9
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• 2015

Background: The aim of this study was to evaluate the effect of autogenous tooth bone as a graft material for regeneration of bone in vertical bony defects of the minipigs. Material and Methods: Six minipigs were used in this study. Four molars were extracted in the right mandibular dentition and sent to the Korea Tooth Bank for fabrication of autogenous tooth bone. Ten days later, each extraction site was implanted with MS Implant Narrow Ridge $3.0{\times}10mm$ fixture (Osstem, Seoul, Korea) after standardized 2mm-sized artificial vertical bony defect formation. Pineappleshaped Root-On type autogenous tooth bones were applied to the vertical defects around the neck area of the posterior three fixtures and the fore-most one was not applied with autogenous bone as a control group. Each minipig was sacrificed at 4, 8, 12 weeks after fixture installation and examined radiologically and histologically. Histological evaluation was done under light microscope with Villanueva osteochrome bone staining with semi-quantitative histomorphometric study. Percentage of new bone over total area (NBF) and bone to implant contact (BIC) ratio were evaluated using digital software for area calculation. Result: NBF were $48.15{\pm}18.02%$, $45.50{\pm}28.37%$, and $77.13{\pm}15.30%$ in 4, 8, and 12 weeks, respectively for experimental groups. The control group showed $37.00{\pm}11.53%$, $32.25{\pm}26.99%$, and $1.33{\pm}2.31%$ in 4,8,12 weeks, respectively. BIC ratio were $53.08{\pm}19.82%$, $45.00{\pm}28.37%$, and $75.13{\pm}16.55%$ in 4,8,12 weeks, respectively. Those for the control groups were $38.33{\pm}6.43%$, $33.50{\pm}29.51%$, and $1.33{\pm}2.31%$ in 4, 8, 12 weeks, respectively. Conclusion: Autogenous tooth bone showed higher score than control group in NBF and BIC in all the data encompassing 4,8,12 weeks specimens, but statistically significant only 12 weeks data in both NBF and BIC.

• 대한소아치과학회지
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• 제21권2호
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• pp.555-560
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• 1994

Among the permanent teeth. the first permanent molars play the greatest role in occlusion and function. So, the congenital missing, abnormal reuption or abnormal formation of the first permanent molars in the course of arch development would inflict normal development of dental arches. Therefore, early detection of abnormal cases related to first permanent molars and understanding of current and predictable clinical problems are essential for proper occlusal guidance in children. With the aim of investigating the clinical patterns of delayed eruption of first permanent molars in children, panoramic tomograms of the childern in mixed and early permanent dentition were observed and analyzed. The results were as follows: 1. Among the delayed eruption of first permanent molars, on tooth or bilateral teeths were affected most frequently. Delayed eruption was more prevalent in maxilla than in mandible. 2. The formation of tardily erupted teeth were also delayed. 3. Delayed eruption was generally limited in first molars or molar segments. 4. Delayed eruption of first permanent molars is accompanied by abnormal position of tooth germs, for example, ectopic eruption, delayed dental age, delayed localized tooth formation and generalized congenital missing. 5. There was a tendency of delayed formation or congenital missing of second molars distal to tardily erupted 1st molars. And that was more marked in maxilla than in mandible. 6. There was reported that affected 1st molars show various size and shapes. Maxillary 1st molars showing delayed eruption showed a tendency of having 3 cusps. But, tardily erupted mandibular 1st molars showed no significant reduction in mesiodistal dimension, as reported. 7. In some cases, the delayed eruption of 1st permanent molars was associated with ectopic eruption, but their formation was not usually retarded. 8. In skeletal class III cases, there showed a tendency of mandibular 1st molars to erupt earlier than maxillary 1st molars with greater interval than in normal occlusion.

• 대한치과교정학회지
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• 제31권5호
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• pp.499-504
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• 2001

하악골 횡적 성장결핍에 의한 하악 전치부의 총생을 치료하는데 성인의 경우 발치가 종종 요구된다. 그러나 발치에 의한 안모 변화가 바람직하지 않을 때 견인골 신장술을 시행하여 하악 정중부의 확장은 횡적 공간을 확보하여 빠른 교정치료 및 안정성을 확보할 수 있는 방법으로 고려된다. 하악 정중부 견인골 신장술을 시행한 후 tooth-borne type 과 tooth & bone-borne type distractor를 사용하여 latency, distraction, consolidation period를 거쳐 하악 정중부 횡적 확장을 시행하여 전치부 총생을 빠르게 치료할 수 있었으며, 두가지 방법에 의한 치유과정을 비교한 결과 치주적인 요소와 골 형성과정은 유사하였으며, 악관절 부위의 퇴행적 증상변화는 관찰되지 않았다.

• International Journal of Oral Biology
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• 제36권1호
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• pp.31-35
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• 2011

Teeth develop via a reciprocal induction between the ectomesenchyme originating from the neural crest and the ectodermal epithelium. During complete formation of the tooth morphology and structure, many cells proliferate, differentiate, and can be replaced with other structures. Apoptosis is a type of genetically-controlled cell death and a biological process arising at the cellular level during development. To determine if apoptosis is an effective mechanism for eliminating cells during tooth development, this process was examined in the rat mandible including the developing molar teeth using the transferase-mediated dUTP-biotin nick labeling (TUNEL) method. The tooth germ of the mandibular first molar in the postnatal rat showed a variety of morphological appearances from the bell stage to the crown stage. Strong TUNEL-positive reactivity was observed in the ameloblasts and cells of the stellate reticulum. Odontoblasts near the prospective cusp area also showed a TUNEL positive reaction and several cells in the dental papilla, which are the forming pulp, were also stained intensively in this assay. Our results thus show that apoptosis may take place not only in epithelial-derived dental organs but also in the mesenchyme-derived dental papilla. Hence, apoptosis may be an essential biological process in tooth development.

• Journal of Periodontal and Implant Science
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• 제38권4호
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• pp.699-708
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• 2008

Purpose: The aim of this study was to investigate the effect of tongue cleaner-equipped manual toothbrush on tooth cleanness, tongue cleanness and malodor index. Materials and methods: 504 subjects were included in this study. At 1st visit, basic information such as age, sex, smoking amount and alcohol consumption was recorded. Self assessment by individual subjects was performed regarding satisfaction to old toothbrush and toothbrushing habit. Tooth cleanness, tongue cleanness and malodor index was assessed by professional researcher. Tongue cleaner-equipped manual toothbrush was given to each subject with proper toothbrushing instruction. After 1 month passed, self assessment and researcher assessment regarding the same index were performed and analyzed statistically by chi-square test. Results: At 1st visit subjects seem to ignore tongue cleansing and showed poor tooth cleanness index, tongue cleanness index and malodor index, however the same subjects were motivated to clean their tongue and teeth and presented statistically improved distribution pattern in tooth cleanness index, tongue cleanness index and malodor index after using tongue cleaner-equipped manual toothbrush(p<0.01). Satisfaction to tongue cleaner-equipped manual toothbrush was 98%. Conclusion: Tongue cleaner-equipped manual toothbrush would be an effective tool for maintaining good oral hygiene through improving tooth and tongue cleanness and preventing malodor formation.

• 대한수의학회지
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• 제50권4호
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• pp.303-310
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• 2010

Demand on specialized feline dentistry has increased over the years, partly due to growing feline population in Korea. Despite the notable increase in the population, not much researches has been conducted on oral disease for stray cats. Thus this research was conducted on 81 adult stray cats from Gwangju in Korea (42 males and 39 females) with average weight of 3.4 kg and also focused on occurrence of periodontal disease (plaque and calculus), feline odontoclastic resorptive lesion (FORL), stomatitis and tooth anomaly. Formation of dental plaque and calculus were abundant on maxilla than mandible, especially distributed much on 4th premolar teeth and 1st molar teeth. After thorough examination of oral cavity, 33 stray cats (40.7%) were found to have oral disease. Eighteen stray cats (22.2%) had tooth fracture which was evident on cuspid and missing teeth were present on 2nd premolar tooth of maxilla and 2nd incisor of mandible amongst 20 stray cats (24.7%). FORL was present on cuspids and 2nd premolar tooth of maxilla among 10 stray cats (12.3%). Stomatitis was involved with FORL, missing tooth, and tooth fracture. Therefore, it was determined that stomatitis, FORL, and periodontal disease were closely associated.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권5호
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• pp.375-379
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• 2011

Introduction: This study examined the effect of autogenous tooth bone used as a graft material for bone regeneration in an artificial bony defect of minipigs. Materials and Methods: Four healthy minipigs, weighing approximately 35-40 kg, were used. Four standardized artificial two-walled bony defects, 5 mm in length and depth, were made on the bilateral partial edentulous alveolar ridge on the mandible of minipigs, and autogenous tooth bone was augmented in the right side as the experimental group. On the other hand, only alloplastic bone graft material HA was grafted with the same size and manner in the left side as the control group. All minipigs were sacrificed at 4 weeks after a bone graft and evaluated histologically by Haematoxylin-eosin staining. The specimens were also evaluated semi-quantitatively via a histomorphometric study. The percentage of new bone over the total area was evaluated using digital software for an area calculation. Results: All specimens were available but one in the left side (control group) and two in the right side (experimental group) were missing during specimen preparation. The amount of bone formation and remodeling were higher in all experimental groups than the control. The mean percentage area for new bone in the experimental and control groups was $43.74{\pm}11.96%$ and $30.79{\pm}2.93%$, respectively. Conclusion: Autogenous tooth bone is a good alternative to autogenous bone with the possible clinical feasibility of an autogenous tooth bone graft in the reconstruction of bony defects.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권3호
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• pp.120-126
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• 2013

Objectives: This study sought to elucidate the effect of autogenous tooth bone material by experimenting on minipig's maxillary sinus and performing histological and histomorphometric analyses. Materials and Methods: Five 18-24 month-old male minipigs were selected, and right maxillary sinuses were grafted with bone graft material made of their respective autogenous teeth extracted eight weeks earlier. The left sides were grafted with synthetic hydroxyapatite as control groups. All minipigs were sacrificed at 12 weeks after bone graft, which was known to be 1 sigma (${\sigma}$) period for pigs. Specimens were evaluated histologically under a light microscope after haematoxylin-eosin staining followed by semi-quantitative study via histomorphometric analysis. The ratio of new bone to total area was evaluated using digital software for calculation of area. Results: All specimens were available, except one on the right side (experimental group), which was missing during specimen preparation. This study demonstrated new bone at the periphery of the existing bone in both groups, showing evidence of bone remodeling, however, encroachment of new bone on the central part of the graft at the 1 ${\sigma}$ period was observed only in the autogenous tooth bone group (experimental group). Histomorphometric analysis showed more new bone formation in the experimental group compared to the control group. Although the difference was not statistically significant (P>0.05), the mean percentage area for new bone for the experimental and control groups were $57.19%{\pm}11.16%$ and $34.07%{\pm}13.09%$, respectively. Conclusion: The novel bone graft material using autogenous tooth is a good alternative to autogenous bone, comparable to autogenous bone, and outperforming synthetic hydroxyapatite bone graft materials in terms of bone regeneration capacity. Augmentation with autogenous tooth bone materials will reduce donor site morbidity without hampering the safety of the autogenous bone graft.

• Applied Microscopy
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• 제46권1호
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• pp.58-66
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• 2016

Thymosin ${\beta}4$ ($T{\beta}4$) has been recently reported to play a role in dentinogenesis by regulating the expression of dentin matrix proteins. Based on previous studies, it is hypothesized that $T{\beta}4$ is associated with the formation of the enamel matrix and thus plays an important role in ameloblast. However, there is no report on the function of $T{\beta}4$ during tooth development so far. Therefore, in this study, we aimed to investigate the expression of $T{\beta}4$ and its function in ameloblasts during mouse tooth development. $T{\beta}4$ was expressed strongly in the tooth bud at the bud stage and in the dental lamina and oral epithelium at the cap stage. In advanced bell stage at postnatal day 4, large elongated ameloblasts were observed and the expression of the $T{\beta}4$ protein was the highest, with the enamel being was thicker than that in the early bell stage. The length of ameloblasts increased from the presecretory to the secretory stage and decreased from the maturation to the protective stage. These results suggest that $T{\beta}4$ participates not only in the proliferation of oral epithelial cells during the early stage of tooth development but also regulates enamel protein secretion in ameloblasts and enamel mineralization.