• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.4
• /
• pp.600-604
• /
• 2003

Tooth impaction is defined as a cessation of the eruption of a tooth at the level of the oral mucosa or alveolar bone. Maxillary canines are the most frequently impacted teeth next to the third molar. Maxillary canine impaction is associated with congenital missing of lateral incisors, peg lateralis and genetic factors such as ectopic positioning of a tooth germ. The clinicians have an important role in early detection of tooth impaction for prevention of esthetic and functional problems. There are specific methods to treat impacted tooth for different conditions. In this case, an 11-year-old girl with a horizontally impacted maxillary right canine in a palatal position was treated through orthodontic traction along with surgical button attachment procedure. On regaining of eruption space, canine traction was performed. At the completion of treatment, the canine was positioned fairly within the arch with proper keratinized gingiva and complications such as root resorption were not observed.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.44 no.1
• /
• pp.99-107
• /
• 2017

In the management of ankylosed primary molars, early diagnosis, proper treatment, and thorough follow-ups are very important. Untreated infraocclusion due to ankylosis has a negative impact on normal occlusal development, and may cause problems. There are many treatment options on infraoccluded deciduous molars, such as periodic observation, conservative method, restoration, and space regaining via extraction of the teeth. In this case report, two 6-year-old girls were diagnosed with ankylosed maxillary second primary molar and displaced tooth germ of the second premolar. Early surgical removal of the ankylosed primary molar was considered as a treatment approach. The long-term follow-up shows normal eruption of a succeeded permanent premolar.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.11 no.1
• /
• pp.131-143
• /
• 1984

150 rats weighting about 150gm were devided into control group of 80 and experimental group of 70. Control group was subdivided into the irradiated vitamin D injection group and X-ray irradiated group. Experimental group was given 2.0mg ergocalciferol by four intramuscular injection prior to X-ray irradiation with single 800 rads and 1,500 rads respectively. Experimental animals from each group was sacrificed after 1, 3, 7, 14, and 28 days and their incisors were investigated by histopathological examination. The results were as follows; 1. In the irradiated groups, it showed dentin hypoplasia and formation of dentinoid substance caused by degeneration of odontoblast at the early stage. Especially, 1,500 rads group which was severely effected showed formation of osteoid dentin at the apical portion and severe injuries of dental papilla at the first week. 2. In the vitamin D2 administration group, it showed thinned dentin layer at the early stage but, taking time, predentin and dentin layer was thickened. At the fourth week, dentin was chiefly composed of interglobular dentin, especially in the lingual portion. 3. Using in combination of overdose vitamin D2 administration and X-ray irradiation, it effected severely odontoblast, undifferentiated mesenchymal cells around tooth germ and pulp tissue. At the early stage, dentin layer was thinned but, taking time, it was thickened and composed of interglobular dentin caused by calcification of predentin layer. 4. In 800 rads irradiation after the overdose vitamin D2 administration, it showed formation of osteoid dentin in the lingual portion at the first week. In the 1,500 rads irradiation after the overdose vitamin D2 administration, it showed formation of osteoid dentin and degeneration of ameloblast in both buccal and lingual portion at the first week, and enamel hypoplasia caused by edema and loss of polarity of ameloblasts at the second week. 5. By the entire experiment, the overdose vitamin D2 administration and X-ray irradiation effected severely odontoblasts, undifferentiated mesenchymal cells of dental papilla, and primitive cells of tooth germ among the dental tissue. Especially using combination of overdose vitamin D2 administration and X-ray irradiation also effected ameloblasts, resulting in enamel hypoplasia.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.28 no.1
• /
• pp.171-191
• /
• 1998

The present study was designed to elucidate the effects of the Co-60 γ irradiation and/or calcium-deficient diet on the periodontal tissue formation in rat pups. The pregnant three-week old Sprague-Dawley rats were used for the study. The experimental group was divided into two groups, irradiation/normal diet group (Group 2) and irradiation/calcium-deficient diet group (Group 3). The control group was non-irradiation/normal diet group (Group 1). The abdomen of the rats at the 19th day of pregnancy were irradiated with single absorbed dose of 350 cGy. The rat pups were sacrificed on the 14th day after delivery, and the maxillae including molar tooth germ were taken. The specimens including the 1st molar tooth germ were prepared to make tissue sections for light and transmission electron microscopy. Some of tissue sections for light microscopy were stained immunohistochemically with anti-fibronectin and anti-osteonectin antibodies. The results were as follows; 1. In the periodontal ligament forming area, the fibroblasts of Group Z showed irregular arrangement and low activity. The immunoreactivity between the fibroblasts and collagen fibers was decreased, compared with Group 1. The fibroblasts of Group 3 showed atrophic change and clumped nucleus. The collagen fibers showed cystic change and low immunoreactivity to the fibronectin. 2. In the cementum forming area, the cementoblasts of Group 2 showed decrease of number and atrophic change. The cementoblasts of Group 3 showed edematous change, atrophy of cytoplasm, and clumping of nucleus. 3. In the alveolar bone forming area, the bone of Group 2 was thin and various degree of immunoreactivity to the osteonectin. Group 3 showed edematous osteoblasts, fibrous degeneration of bone marrow, and weak immunoreactivity to the osteonectin.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.39 no.4
• /
• pp.390-396
• /
• 2012

Infraocclusion is defined as tooth whose relative occlusal movement was blocked during the period of active eruption due to ankylosis and so on. Then infraoccluded tooth remains under the occlusal plane composed by adjacent structures showing normal eruption patterns. Untreated infraocclusion may cause: prolonged retention of infraoccluded teeth; extrusion of apposed teeth; destruction of periodontal tissues by occlusal force and food packing; increased sensitivity for dental caries; and disturbances on eruption pathway of succedaneous teeth. Therefore, periodic check-ups and proper treatments are required. There are many treatment options on infraoccluded deciduous molars such as periodic observation, conservative method, restoration and space regaining with extraction of the teeth. The choice of treatment may depend on the presence of succedaneous teeth, time of diagnosis and degree of infraocclusion. In this case report, three patients showing displacement of the second premolars due to infraocclusion of upper second primary molars, were treated by means of space regaining with removable orthodontic appliances and extraction of ankylosed primary molars. All malpositioned permanent premolars in the 3 cases showed ordinary eruption pathways after treatment.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.1
• /
• pp.109-116
• /
• 2010

Impaction is defined as a cessation of the eruption of a tooth caused by a clinically or radiographically detectable physical barrier in the eruption path or by an ectopic position of the tooth. The reasons for impaction of the maxillary central incisor are supernumerary tooth, odontoma, ectopic position of tooth germ, dilacerated tooth and so force. Impacted tooth cause space loss due to proximal movement of adjacent tooth, malocclusion, root resorption of adjacent tooth, cyst formation, so careful observation and early detection is important and exact treatment should be applied to prevent these results. The treatment options of impacted tooth include induction an eruption through extraction of deciduous tooth or surgical exposure, reposition of impacted tooth by surgical method or orthodontic treatment. Orthodontic traction is recommended when an eruption does not happen after removal of barrier or surgical exposure, when eruption path is too transpositioned to be corrected spontaneously so eruption does not expected. In these cases, traction of impacted maxillary central incisor was carried out using orthodontic method with closed eruption technique and it showed good clinical results so we report these cases.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.34 no.2
• /
• pp.329-334
• /
• 2007

The infection of primary teeth occurs by caries or trauma. But, if it is not treated on time, the complication may occur such as enamel hypoplasia, discoloration, impaction, displacement and dilaceration of permanent successors. The periapical lesion on primary tooth could displace the permanent successors in any direction. Treatment options of displaced tooth are observation after extracting the primary teeth, surgical exposure orthodontic traction, transplantation and extraction. In these cases, displacement of permanent central incisor caused by the periapical lesion of primary teeth was observed. The spontaneous eruption after extraction of primary teeth was expected considering degree of displacement, development of root and direction of eruption. This case report shows spontaneous eruption of displaced permanent tooth germ was achieved with periodic examination after extraction of primary teeth.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.39 no.2
• /
• pp.166-173
• /
• 2012

Dilaceration is a developmental disturbance in shape of teeth. It refers to an angulation, or a sharp bend or curve, in the root or crown of a formed tooth. Dilacerations are estimated to occur in 3% of all permanent dentitions. However, the etiology of dilaceration is not yet fully understood. Traumatic injury to the deciduous predecessors and ectopic development of the tooth germ are the two commonly cited causes of this anomaly. The involved tooth is usually the maxillary central incisor and it also shows high prevalence of impaction. At first, We tried to do surgical exposure with orthodontic traction but to no avail. After then surgical repositioning of the dilacerated tooth was performed. Finally, Satisfactory results were obtained at the end of treatment, with improvement in dental esthetics and functional aspects.

• Proceedings of the KACD Conference
• /
• 2003.11a
• /
• pp.546.2-546
• /
• 2003

Dental follicle is the mesenchymal tissue which surrounds developing tooth germ. During tooth root development, periodontal components such as cementum, periodontal ligament and alveolar bone are considered to be created by progenitors present in the dental follicle. However, little is known about these progenitors. Previously we observed that cultured bovine dental follicle cells (BDFC) contained putative cementoblast progenitors. To further analyze the biology of these cells, we have attempted to immortalize BDFC by expression of the polycomb group protein Bmi-1 and human telomerase reverse transcriptase (hTERT). The BDFC expressing Bmi-1 and hTERT showed extended life span by 90 population doublings more than normal BDFC, and still contained cells with potential to differentiate into cementoblasts upon implantation into immunodeficiency mice. Among them, we established a clonal cell line designated as BCPb8, which formed cemetum-like mineralized tissue reactive to anti-cementum specific monoclonal antibody, 3G9, and expressed mRNA for bone sialoprotein, osteocalcin, osteopontin and type I collagen upon implantation. Thus with the combination of hTERT and Bmi-1, we succeeded in immortalization of cementoblast progenitor in BDFC without affecting differentiation potential. The BCPb8 progenitor cell line could be a useful tool not only to study cementogenesis but also to develop regeneration therapy for periodontitis.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.32 no.1
• /
• pp.26-32
• /
• 2005

A tooth impaction means a state that a tooth does not erupt out of oral mucosa or alveolar bone for many reasons. The reasons for an impaction of the Maxillary central incisor are an odontoma, supernumerary tooth, space loss, prolonged remaining or early loss of a preceding deciduous tooth, abnormalities of crown or root caused by trauma of a deciduous tooth and an ectopic position of a tooth germ. In the case of the impacted maxillary incisor, a rapid mesial movement of a lateral incisor leads a space loss and a midline deviation can be happened. Furthermore, it can cause a cyst. When we treated a patient with an impacted central incisor early, we could see a better prognosis. It means an early diagnosis and an exact treatment are very important. Generally if the impaction is not severe or it is caused by a keratinized covering tissue, a surgical exposure can induce an eruption easily but an orthodontic force is recommended when an eruption does not happen after a surgical method, when the eruption path is too transpositioned to be corrected spontaneously and when an impacted tooth is located so deeply. In the treatment using an orthodontic force, careful considerations about a root length, pulp, and a periodontal tissue can improve the periodontal and esthetic prognosis for the long follow-up results. This case is using an orthodontic traction following a periodic observation and in no expectation of spontaneous eruption. After treatment of this case, I have got some knowledges, so I report this case.