• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.489-494
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• 2003

Odontomas are the common type of odontogenic tumors and generally they are asymptomatic, depending upon size, location and their limited growth potential. they are rarely diagnosed before the second decade of life, and the frequently lead to impaction or delayed eruption of permanent teeth. Odontomas are classified of compound as compound or complex by morphology. Complex odontomas are unorganized masses of odontogenic tissues, morphologically not resembling the teeth, account for approximately 25 percent of all odontomas, 22 percent of odontogenic tumor of the jaws, and have a predilection for the posterior mandible in males. The etiology of odontomas is unknown, although local trauma, infection, and genetic factors have been suggested. Usually, treatment of odontoma is conservative sugical removal and their is little probability of recurrence. This paper describes two cases of complex odontomas diagnosed in children due to impaction of maxillary first molar in all cases, the surgical excision of the lesions was performed. Follow-up after 2 years, showed spontaneous eruption of the first permanent molar to the occlusal plane.

• The korean journal of orthodontics
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• v.24 no.1 s.44
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• pp.37-62
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• 1994

This study was undertaken to investigate the three dimensional vascular changes of periodontal ligament following orthodontic tooth movement. Experimental tooth movement was carried out in 96 Sprague-Dawley rats with the weight of 250g. They were divided into four experimental groups (each 24 rats). The left maxillary first molar was moved mesially with 25g force in group I, and with 75g force in group II. Each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days. In group III, 25g mesial force was applied for 3 days, and in group IV, 75g mesial force was applied for 3 days. Then the appliances were removed, and each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days from removal of appliance. The contralateral molars were used for control group. Casting media was injected via left ventricle and polymerized in warm water. After corrosion of surrounding soft tissue, three dimensional vascular changes were examined using scanning electron microscopy. The findings of this study were as follows: 1. Pressure side of group I and II showed degenerative vascular changes such as vascular compression, reduction of vasculature, leakage of casting media. But, regenerative changes were dominant after 7 days of tooth movement. Although the degenerative vascular changes were more severe in group II, which was exposed to heavy force, the timing of these changes was not different between two groups. 2. Periodontal vasculature was reestablished by the growth of new capillaries and their differentiation and union from the remaining periodontal vessels and vessels of alveolar bone marrow. Although vascular regeneration was more rapid in group I, which was exposed to light force, the vasculature was not fully normalized in both groups even after 21 days. 3. There was no remarkable changes in tension side of group I and II, but looping of capillary, new capillary growth, dilation of vessels, redirection of vessels in the direction of tensile force were occurred. 4. In pressure side of group III and IV, in which appliance was removed after 3 days of orthodontic force, bone resorption was continued even after removal of appliance. Regeneration of vasculature was initiated after 1-6 hours, and it was more rapid in group III than group IV. In both groups, the vasculature was not fully normalized even after 21 days. 5. After removal of appliance, tension side of group III and IV showed vascular compression and loss of vasculature.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.317-325
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• 1999

In proper diagnosis of skeletal Class III malocclusion, it was important to know the pattern of three dimensional skeletal & facial disharmony. The purpose of this study was to obtain P-A cephalometric characteristics in skeletal Class III malocclusion comparing with normal occlusion. The samples were consisted of 120 subjects, divided into four groups : Male normal occlusion, Female normal occlusion, Male skeletal Class III malocclusion, Female skeletal Class III malocclusion. Posteroanterior and lateral cephalogram were taken from the subjects with a x-ray apparatus (ASHAI CX90SP, Japan) and traced on acetate paper with routine manner. The transverse and vertical values from posteroanterior cephalometry, the sagittal values from lateral cephalometry and their ratio were obtained. The results were as follows: 1. The anteroposterior discrepancy in skeletal Class III group was not due to short maxillary length(Cd-A), but to longer mandibular length(Cd-Gn) than normal occlusion group. 2. The faces of skeletal Class III group were longer than normal occlusion group. It was not due to increase of upper face height(Cg-ANS) but to increase of the lower face height(ANS-Me) especially mandibular height(Cd-Me). 3. There was no difference in the facial width values between normal occlusion group and skeletal Class III group, except upper molar width(U6-U6), lower molar width(L6-L6) and mandibular width(Ag-Ag) of female skeletal Class III group which were larger than normal occlusion group. 4. The increase of mandibular length of skeletal Class III group was reflected in the increase of lower facial height but did not have an effect on the mandibular width.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.27.1-27.9
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• 2019

Background: Implants are becoming the first choice of rehabilitation for tooth loss. Even though they have a high success rate, failures still occur for many reasons. The objective of this study is to analyze the reasons for recurring failure at the same site and the results of re-implantation. Methods: Thirteen patients (11 males and 2 females, mean age 60 ± 9.9 years) who experienced implant surgery failure at the same site (same tooth extraction area) two or more times in the Department of Oral and Maxillofacial Surgery, Seoul National University Bundang Hospital, between 2004 and 2017 were selected. The medical records on a type, sites, diameter, and length of implants; time and estimated cause of failure; and radiographs were reviewed. Data were collected and analyzed retrospectively, and the current statuses were evaluated. Results: A total of 14 implants experienced failure in the same site more than two times. Twelve implants were placed in the maxilla, while 2 implants were placed in the mandible. The maxillary molar area was the most common site of failure (57.1%), followed by the mandibular molar, anterior maxilla, and premolar areas (14.3% each). The first failure occurred most commonly after prosthetic treatment (35.7%) with an average period of failure of 3.8 months after loading. Ten cases were treated as immediate re-implantation, while the other 4 were delayed reimplantation after an average of 3.9 months. The second failure occurred most commonly after prosthetic treatment (42.9%), with an average of 31 months after loading; during the healing period (42.9%); and during the ongoing prosthetic period (14.3%). In 3 cases (21.4%), the treatment plan was altered to an implant bridge, while the other 11 cases underwent another implant placement procedure (78.6%). Finally, a total of 9 implants (64.3%) survived, with an average functioning period of 60 months. Conclusions: Implants can fail repeatedly at the same site due to overloading, infection, and other unspecified reasons. The age and sex of the patient and the location of implant placement seem to be associated with recurring failure. Type of implant, bone augmentation, and bone materials used are less relevant.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.33.1-33.7
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• 2019

Background: The concept of the ideal morphology for the alveolar bone form is an important element to reconstruct or restore the in maximizing esthetic profile and functional alveolar bone restoration. The purpose of this preliminary study is to evaluate the normal alveolar bone structure to provide the standard reference and guide template for use in diagnosing for implant placement, determining the correct amount of bone augmentation in actual clinical practice and producing prostheses based on three-dimensional imaging assessment of alveolar bone. Methods: This study was included 11 men and 11 women (average age, 22.6 and 24.5 years, respectively) selected from among 127 patients. The horizontal widths of alveolar bone of maxilla and mandible were measured at the crestal, mid-root, and root apex level on MDCT (multi-detector computed tomography) images reconstructed by medical imaging software. In addition, tooth dimensions of the central incisors, canines, second premolars, and first molars of maxilla and mandible, including the horizontal width of the interdental alveolar bone crest, were also measured and statistically analyzed. Results: The horizontal alveolar bone width of the palatal side of maxilla showed a distinct increment from the alveolar bone crest to the apical region in both anterior and posterior areas. The average widths of the maxillary alveolar ridge were as follows: central incisor, 7.43 mm; canine, 8.91 mm; second premolar, 9.57 mm; and first molar, 12.38 mm. The average widths of the mandibular alveolar ridge were as follows: central incisor, 6.21 mm; canine, 8.55 mm; second premolar, 8.45 mm; and first molar, 10.02 mm. In the buccal side, the alveolar bone width was not increased from the crest to the apical region. The horizontal alveolar bone width of an apical and mandibular border region was thinner than at the mid-root level. Conclusions: The results of the preliminary study are useful as a clinical guideline when determining dental implant diameter and position. And also, these measurements can also be useful during the production of prefabricated membranes and customized alveolar bone scaffolds.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.651-657
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• 2007

Odontomas are the common type of odontogenic tumors and generally are asymptomatic and frequently lead to impaction or delayed eruption of permanent teeth. They are composed of enamel, dentin, cementum and pulp tissue and are divided into compound and complex according to the morphology of the hard tissues. Compound odontomas consist of varying numbers of small toothlike structure and have a predilection for the maxillary anterior regions. Complex odontomas consist of an unorganized mass of odontogenic tissues and comprise approximately 25 percent of all odontomas and have a predilection for the mandibular posterior regions. The etiology of odontomas is uncertain but hypothesized to involve local trauma, infection and genetic factors. Treatment of odontoma is conservative surgical removal and are little probability of recurrence. These two cases were about the patients with delayed eruption of mandibular first molar and mandibular lateral incisor. We surgically removed odontoma, exposed impacted tooth and guided impacted tooth into normal position by orthodontic traction. At the completion of traction, the mandibular first molar and mandibular lateral incisor was positioned fairly within the arch and complications such as root resorption were not observed.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.3
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• pp.176-183
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• 2012

Purpose: This study examined the clinical success rate of Mg titanate implants (M Implant system, Shinhung, Korea), which employ a Mg coating method, by evaluating the marginal bone loss and implant stability using radiographs and Osstell$^{(R)}$, over a 1 year. Materials and methods: The locations of the implants placement were divided into 4 areas; the maxillary and mandibular premolars and molars. In the maxilla, 8 and 9 implants were inserted in the premolar and molar areas, respectively. In the mandible, 11 and 51 implants were inserted in the premolar and molar areas. Marginal bone loss and ISQ of all implants (79) were measured after insertion, mounting the prosthetic appliance, and 1, 3, 6, and 12 months after loading. The marginal bone loss was measured from the radiograph using XCP bite, which was customized, and the implant stability measured using Osstell$^{(R)}$. Fisher's exact test (${\alpha}$=.05) was used to compare the success rates of each region. Results: The mean marginal bone loss for the upper and lower jaws were 1.537 mm and 1.172 mm. The mobility showed a non-significant reduction or increase according with time. The success rates were accounted for 94.12% and 98.39% in the upper and lower jaws; the premolars and molars were accounted for 100% and 96.67%. The two cases of early failure resulted from failure of primary stability during implant insertion. The late failures were not observed for 1 year after adding a loading to the implants. Conclusion: The Mg titanate implant showed good primary stability and good clinical results in both healing and function.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.4
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• pp.321-327
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• 2013

Ameloblastic fibroma (AF) is a rare odontogenic ectomesenchymal tumor that is frequently seen in the first two decades of life, and occurs in the mandible. The most proper management of AF has been a recent topic of debate because of its recurrence and malignant transformation. This report describes AF in a 4-year-old male, which was a unilocular radiolucency on the maxillary right primary molar area with a scalloped border and corticated margin. The tumor was treated conservatively with enucleation and curettage, and the decision was made to preserve the right primary second molar. A biopsy confirmed it as AF. During the 43 months of follow-up, the patient had no evidence of recurrence or malignant transformation. Moreover, the radiographic examination revealed the generation of tooth germ to be a permanent second premolar. This report shows a case of AF in the posterior maxilla of a 4-year-old boy and discusses the conservative therapeutic approach to this tumor. Therefore, the age of the patients should be an important consideration when choosing conservative or radical surgery in a young AF patient.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.4
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• pp.417-429
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• 2009

Since the introduction of the concept of osseointegration in dental implants, high long-term success rates have been achieved and accepted as viable option for the treatment of fully and partially edentulous patients. Although the use of domestic implants have increased dramatically, there are few studies on domestic implants with clinical and objective long-term data. 96 endosseous implants placed in 31 patients at Wonkwang University Sanbon Dental Hospital were examined to determine the effect of various factors on implant survival rate and marginal bone loss, through clinical and radiographic results. The design of endosseous implant used to this study is straight with the microthread.(GS II RBM Fixture) 1. 3 fixtures were lost, resulting in 96.9% cumulative survival rate. 2. Survival rate in fifties was significantly lower (93.6%) and no significant difference in marginal bone loss was found according to gender. 3. Survival rates were 95.6% in the maxillary molar area and 97.3% in the mandible molar area. 4. No significant difference in survival rate was found according to presence of bone grafts, type of prostheses, implant position, and length and diameter of implant. 5. A factor influencing marginal bone loss was presence of type of prostheses, while facters such a length, diameter of fixture and bone grafts had no statistically significant effect on crestal bone loss. This study indicates the amount of marginal bone loss around implant has maintained a relative stable during follow-up periods.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.644-648
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• 2005

Supernumerary tooth was resulted from excessive proliferation of dental lamina and associated with familial tendency and a congenital syndrome such as Cleidocranial dysostosis or Gardner's syndrome. Incidence reports identify a range of $0.3{\sim}0.8%$ in primary dentition, $1.0{\sim}3.5%$ in permanent dentition with males being affected twice as frequently as females, maxilla nine times as frequently as mandible. The most common supernumerary tooth is the mesiodens, which located between the maxillary central incisors, and the next common site is the fourth molar and lateral incisors. Supernumerary teeth are uncommon in the mandible, but premolars are the most common supernumerary teeth and occurrence is very rare in the incisor region of the mandible and the incidence is 2%. We need a early diagnosis and appropriate treatment plan because of possiblilty of diastema and eruption failure displacement, rotation of the associated permanent teeth, root resorption and dentigerous cyst with presence of the supernumerary teeth. In this two case, one supernumerary tooth located in the mandibular incisor region, the other supernumerary tooth located in premolar region. We could get normal alignment of mandibular dentition by extraction and orthodontic treatment.