• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.1
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• pp.77-82
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• 2011

A long-term follow-up study of a case of impacted teeth associated with a large dentigerous cyst in the left maxilla is presented. The patient was a 30-year-old man who had a large dentigerous cyst in the premaxilla and left posterior maxilla, which impacted the canine and supernumerary tooth. This is one of the most prevalent types of odontogenic cysts associated with an erupted or developing tooth, particularly the mandibular third molars. The other teeth commonly affected in order of frequency are the maxillary canines, maxillary third molars and rarely, the central incisor. Radiographically, the cyst appears as huge ovoid well-demarcated unilocular radiolucency with a sclerotic border and causes ectopic displacement of the inferior border of the maxillary sinus without destruction. Dentigerous cysts may grow unnoticed to such extensive sizes as to occupy a considerable portion of the maxillary sinus. These cysts appear to be associated with a supernumerary tooth in the maxillary anterior incisors region called the mesiodens and impacted canine. The present case report describes the surgical enucleation of a dentigerous cyst involving the permanent maxillary left canine and mesioden. After surgery, left maxillary sinus recovered their normal size and apposition of bone was observed around the apex of the posterior teeth. During the subsequent years, there was no recurrence of the cystic lesion but the inflammation was evoked in the anterior maxilla after 42 months. This complication appeared to have correlated with bony healing in the enucleation site of the cyst. We report the healing status of a huge dentigerous cyst in the maxilla for 5 years with a review of the relevant literature.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.6
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• pp.570-578
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• 2006

A severely atrophic maxilla may disturb the proper implant placement. The various bone graft techniques are required for simultaneous or delayed implantation in the cases of atrophic alveolar ridges. We present 11 consecutive patients treated with simultaneous implantation using the autogenous inlay and/or onlay bone grafts from iliac crest to the floor of the maxillary sinus and the alveolar crest. In the cases of atrophic maxilla, a total 69 implants were simultaneously placed with autogenous iliac bone graft. 40 fixtures were inserted in the sinus floor simultaneously with subantral block bone graft, the other 29 fixtures were placed in the anterior or premolar areas with block or particulate bone graft. The vertical alveolar bone height was measured with Dental CT at the preoperation and 6 months postoperation. Moreover, the implant stability quotients (ISQ) were measured by $Osstell^{TM}$ during second implant surgery at 6 months later of first implantation. All implants were obtained successful osseointegration with the grafted bone. The mean vertical increases were 3.9mm in the anterior ridges and 12.8mm in the posterior ridges. During the second implant surgery, mean ISQ were 62.95 in the anterior ridge and 61.32 in the posterior ridge. We concluded that the simultaneous implantation with autogenous iliac bone graft were stable and available methods for severely atrophic maxilla.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.4
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• pp.182-187
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• 2013

Keratocystic odontogenic tumors (KCOT) - previously termed odontogenic keratocysts (OKC) - are characterized by aggressive behavior and a high rate of recurrence. Histopathologically, the basal layer of KCOT shows a higher cell proliferation rate and increased expression of anti-apoptosis genes. Clinically, KCOT is frequently involved in the mandibular posterior region but is not common in the posterior maxilla. However, it should be noted that due to its expansive characteristics, KCOT involved near the maxillary sinus could easily expand to an enormous size and occupy the entire maxilla. To achieve total excision of these expanded cystic tumors in the maxilla, a more aggressive approach would be needed. In this report, we describe two cases of expansile KCOT involving the entire unilateral maxilla and maxillary sinus; they were completely excised using the Weber-Ferguson approach, showing no evidence of recurrence during the follow-up period of more than two years. In immunohistochemical analyses of the tumor specimens, p53 and p63 showed strong expression, and B-cell lymphoma 2 (BCL2) and MKI67 (Ki-67) showed moderate or weak expression, however, detection of BCL2-associated X protein (BAX) was almost negative. These data indicate that expansile KCOT possesses increased anti-apoptotic activity and cell proliferation rate but decreased apoptosis. These properties of KCOT may contribute to tumor enlargement, aggressive behavior, and high recurrence rate.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.2
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• pp.235-248
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• 1994

There were many studies that distribute the partial edentulous states and examine the removable partial denture designs in the planning of removable partial denture treatment. This study was performed in the point of removable partial denture prescription to evaluate partial edentulism and its removable partial denture designs. The data was collected from the dental laboratory of each three dental colleges in Seoul and from two dental laboratories only for removable partial dentures as a prescription form. A total of 1411 cases with prescription form collected from dental laboratories were distributed for this study, then 788 cases were selected for this study. The case selection was done according to the contents of prescription form. The selected cases were divided into maxillary arch and mandibular and classified in terms of types of major connector and direct retainer, unbroken anterior teeth, Kennedy classification, the number of remaining teeth, and distribution of age and sex. The analyzed results were as follows : 1. The Kennedy classification I showed highest frequency both in maxilla and mandible. 2. The arch distribution of removable partial denture was 50.08% for maxilla and 49.92% for mandible. 3. The highest frequency in the distribution of direct retainer was the RPA clasp design. 4. The frequency of unbroken anterior 6 was 73.36% for maxilla and 82.30% for mandible. 5. The design of broad palatal strap and lingual bar revealed the highest prevalence in the major connector construction. 6. The mean number of remaining teeth per arch was 8.25 for maxilla and 8.37 for mandible. 7. The mean age of the patients supplied with removable partial denture was 52.25 years for men, 51.68 years for women, 52.11 years for maxilla, and 51.76 years for mandible and women showed more prevalence.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.3
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• pp.170-175
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• 2009

Purpose : The purpose of this study is to evaluate 7-year survival rate of implants placed without bone graft in posterior maxilla and compare the survival rate by the age and gender of patient, length and diameter of implant, region of implant placement, bicortical engagement of fixture, and connection of prosthesis. Material and methods : 78 patients (170 implants) who visited our institution from 2002 to 2007 and were followed up with panoramic view and medical records. Kaplan-Meier survival analysis and Log Rank (Mantel-Cox) test were used. Results and conclusions : A 7-year cumulative survival rate for implants placed in posterior maxilla without sinus graft was 95.3%. The survival rate in men was 91.8%, significantly lower than 98.8% in woman.(p<0.05). However, the survival rate by the length of the implants did not show any significant differences.(p>0.05), while the wide platform implant resulted in 85% survival rate which was statistically lower than 98.5% in regular platform. The posterior maxillary implants engaged bicortically showed 97.6% of 7-year Survival rate, comparing 88.6% in not engaged implants. The survival rate of the single implant was 91.2%, while 98.5% in splinted prosthesis. Therefore, the bicortical engagement of the fixtures and splinted prosthesis may be recommended to get a long-term survival rate in posterior maxilla.

• Imaging Science in Dentistry
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• v.43 no.4
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• pp.227-233
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• 2013

Purpose: This study was performed to analyze human maxillary and mandibular trabecular bone using the data acquired from micro-computed tomography (micro-CT), and to characterize the site-specific microstructures of trabeculae. Materials and Methods: Sixty-nine cylindrical bone specimens were prepared from the mandible and maxilla. They were divided into 5 groups by region: the anterior maxilla, posterior maxilla, anterior mandible, posterior mandible, and mandibular condyle. After the specimens were scanned using a micro-CT system, three-dimensional microstructural parameters such as the percent bone volume, bone specific surface, trabecular thickness, trabecular separation, trabecular number, structure model index, and degrees of anisotropy were analyzed. Results: Among the regions other than the condylar area, the anterior mandibular region showed the highest trabecular thickness and the lowest value for the bone specific surface. On the other hand, the posterior maxilla region showed the lowest trabecular thickness and the highest value for the bone specific surface. The degree of anisotropy was lowest at the anterior mandible. The condyle showed thinner trabeculae with a more anisotropic arrangement than the other mandibular regions. Conclusion: There were microstructural differences between the regions of the maxilla and mandible. These results suggested that different mechanisms of external force might exist at each site.

• The korean journal of orthodontics
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• v.20 no.3 s.32
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• pp.519-539
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• 1990

It is the aim of this study to observe the distribution of various facial types in class III malocclusion and to characterize the craniofacial features of the very facial types. Cephalometric headptates of a hundred and ten persons showing bilateral class III malocclusion whose mean age was 12.51 years and sixty nine persons of normal occlusion whose mean age was 12.23 years were measured and statistically analyzed. The following summary and conclusions were drawn. 1. Affording the bases for SNA and SNB, $35.45\%$ of sample showed normally positioned maxilla and protruded mandible, $30.00\%$ for retruded maxilla and normally positioned mandible, $15.45\%$ for retruded maxilla and protruded mandible, $10.90\%$ for both maxilla and mandible within normal range and $8.20\%$ for miscellaneous types were arranged in class III malocclusion. 2. $52.72\%$ of sample showed neutrodiveigent, $35.45\%$ for hyperdivergent and $11.81\%$ manifested hypodivergent mandible in class III malocclusion. 3. Providing the bases for facial and mandibular planes, $33.63\%$ of sample showed prognathic and neutrodivergent, $20.90\%$ for mesognathic and hyperdivergent, $17.27\%$ for prognathic and hyperdivergent and $15.45\%$ for mesognathic and neutrodivergent were arranged in class III malocclusion. 4. The class III malocclusion brought out shorter cranial base, smaller saddle angle, and larger articular and genial angle. It showed retropositioned maxilla and forward positioned mandible in spite of no significant differences in linear measurements of mandible. Anterior lower facial height was significantly larger in class III malocclusion, while posterior total facial and anterior total facial heights exhibited no significant differences. 5. It is suggested class III malocclusion was attributed to shorter cranial base, smaller saddle angle, maxillary deficiency and/or retrusion, mandibular excess and/or protrusion, excessive vertical growth of the anterior lower face, and their complex as well.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.349-366
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• 1994

The method of treatment in skeletal Class III malocclusion must be chosen according to an etiology and timing of the treatment. Maxillry protraction has been used as an effective treatment method in growing children with maxillary deficiency. The efficacy of maxillary protraction has been viewed as a result of downward-backward displacement of mandible and compensatory dental displacement during the treatment rather than forward -downward growth of maxilla itself. In this study, 104 subjects treated with maxllary protraction, and 19 males and 21 females with known annual growth amount have been chosen longitudinally as treated group and normal group, respectively. And changes in position of maxilla, mandible and dentition have been comparatively analyzed on the lateral cephalometric radiographs by age. The results were as follows : 1. Treated group showed more forward movement of maxilla compare to the normal group and the mandible displaced backward compare to the normal group. 2. Downward movement of maxilla in treated group was similar to that of normal group with statistical signigicance in female 12 year old group and downward movement of mandible in treated group was similar to that of normal group. 3. In treated group, maxillary central incisor moved more forward than the normal group with statistical significance in male 8, 10 year-old groups and female 8, 9, 10 year-old groups. In treated group, downward movement of maxillary central incisor was similar to that of the normal group with statistical significance in male and female 7,8 year-old groups. Considering the above results and the duration of the treatment, the forward movement of maxilla due to maxillary protraction was effective compared to normal growth amount of the normal group.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.3
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• pp.186-190
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• 2017

A surgical approach involving the retromolar trigone, posterolateral maxilla, and pterygoid region is the most challenging in the field of maxillofacial surgery. The upper cheek flap (Weber-Ferguson incision) with subciliary extension and the maxillary swing approach have been considered as alternatives; however, neither approach provides sufficient exposure of the pterygoid region and the anterior portion of the mandibular ramus. In this report, we describe two cases in which a lower cheek flap approach was used for complete tumor resection in the retromolar trigone and the anterior mandibular ramus. This approach allows full exposure of the posterolateral maxilla and the pterygoid region as well as the retromolar trigone without causing major sensory disturbances to the lower lip. A mental nerve anastomosis after tumor resection was performed in one patient and resulted in approximately 90% sensory recovery in the lower lip. The lower cheek flap approach provides adequate exposure of the posterolateral maxilla, including the pterygoid, retromolar trigone, and mandibular ramus areas. If the mental nerve can be anastomosed during flap approximation, postoperative sensory disturbances to the lower lip can be minimized.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.5
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• pp.348-352
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• 2002

Ameloblastoma of the maxilla is an unusual epithelial tumor of odontogenic origin. According to many authors and reports, ameloblastoma account for approximately 1% of all tumors of the jaws, but when pseudotumors and cysts are excluded, the ratio rises to 11%. Of these tumors,80% originate in the mandible, while 20% originate in the maxilla. Although it is considered benign histopathologically, it can behave in a slowly growing infiltrative fashion, with multiple recurrences and eventual intracranial, or even distant, spread. We clinically analyzed common site in maxilla, radiographic findings, recurrence rate, duration between treatment and recurrence, the presence and site of distant metastasis in 15 patients who were diagnosed as ameloblastoma of the maxilla and took treatments from 1985 to 1999 in Dept. of Oral and Maxillofacial Surgery, Dental Hospital, Seoul National University. In this paper, treatment outcomes and our clinical experiences of maxillary ameloblastoma are reported with review of literatures.