• The korean journal of orthodontics
• /
• v.13 no.1
• /
• pp.31-43
• /
• 1983

The following results were abtained based on the research of the occlusal patterns among 1074 handicapped persons (cerebral palsy: 46, mental subnormality: 619, deafmute: 285, blind: 111, childish autism:8, cleft lip and cleft palate:3, polimyelitis:2) of the age between 6 and 23 in Chollanamdo, Korea, in comparison with a normal group of 1048 children of the age between 6 and 15 selected at random in J primary school in Gwang-ju City. 1. According to Angle's malocclusion classification, all the handicapped groups, except the cerebral palsy and the blind, showed a higher prevalence of malocclusion than that of the normal. Especially the prevalence of Class II, devision 1 malocclusion in the cerebral palsy was the highest, and the prevalence of Class III malocclusion in all the handicapped groups was higher than that of the normal group. Among these groups the highest prevalence of Class III malocclusion was in the Down's syndrome group. 2. On the the abnormal pattern of the anterior region, there was no significant difference $(P\leqq0.05)$ between the normal and the cerebral palsy, the deafmute, and e blind. The open bite $(7.27{\pm}1.04\%)$ and the cross-bite $(32.7{\pm}6.33\%)$ of the Down's syndrome wire higher than that of the normal, and the forward position of the mandible could be recognized in the Down's syndrome group. 3. On the midline position of the dentition, all the handicapped showed the same percentage of deviation, but the degree of mandibular shift to the right $(20.00{\pm}5.39\%)$ or left $(10.91{\pm}4.20\%)$ was higher than that of the normal only in the Down's syndrome group. 4. On the abnormal pattern of the posterior region, the cross-bite of the Down's syndrome was higher than that of the normal by $20.00{\pm}5.39\%$, the cross-bite of the cerebral palsy and the cross-bite and the open bite of the mental subnormality were slightly higher than that of the normal. The other handicapped groups showed no significant difference $(P\leq0.05)$ to the normal.

• Imaging Science in Dentistry
• /
• v.32 no.2
• /
• pp.89-97
• /
• 2002

Purpose: The objective of this study is to find the differentiating characteristics of ameloblastomas and odontogenic keratocysts of the jaw by analyzing computed tomography (CT) images of the lesions, clarify radiological characteristics associated with jaw lesions, and to make a diagnsis based on these findings. Materials and Methods : Test subjects were chosen among the patients who were diagnosed as having an odontogenic keratocyst or ameloblastoma at the Yonsei University Dental Hospital from January 1996 to December 2000 and had CT scans taken preoperatively. The subject pool was comprised of 51 cases of odontogenic keratocyst and 37 cases of ameloblastoma. The following measures were used for image analysis of the lesion: the anatomic location, CT pattern, mesiodistal width, buccolingual width, the ratios between mesiodistal width and buccolingual width, height, CT number, homogeneity of radiodensity, the appearance of a sclerotic rim, continuity of adjacent cortical bone, and displacement and resorption of adjacent teeth. Results: Comparing the CT patten, mesiodistal width, buccolingual width, height, CT number, homogeneity, appearance of sclerotic rim, continuity of adjacent cortical bone, there were statistically significant differences between ameloblastoma and odontogenic keratocyst test subjects (p<0.05). Comparing the ratios between mesiodistal width and buccolingual width, displacement and resorption of adjacent teeth, there were no statistically significant differences (p>0.05). Conclusion: We compared odontogenic keratocysts and ameloblastomas in CT scans. They occurred most frequently in the posterior to the ramus of the mandible. The findings of patterns of the CT images showed that size and border of lesions were more aggressive in ameloblastomas than in odontogenic keratocysts. The internal contents represented an increased attenuation area (IAA) in odontopenic keratocyst. Odontogenic keratocysts were shown to have higher CT numbers than ameloblastomas.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.19 no.1
• /
• pp.89-101
• /
• 1989

The author observed and analyzed the age, sex, chief complaint and radiographic finding of sixty-one cases of benign odontogenic tumors seen in Yonsei Medical Center, for the period of Jan. 1979 to Aug. 1989. The results were as follows: 1. Benign odontogenic tumors of 61 cases included 52 cases (85.3%) of ameloblastoma and odontoma, and 9 cases of other lesions. Radiographically, the border of the lesions were well-defined. 2. Ameloblastoma constituting twenty-seven cases (44.3%) occurred the average age of 31.1 years and had a 3:1 male predominance. The most common complaint was swelling (20 cases, 74.0%) and followed by pain (13 cases, 48.2%). Radiographically, the most common site was mandibular body area (74.0%) and the lesions were mainly multiocular radiolucency; in 17 cases (63.0%) and unilocular radiolucent lesion were seen in 10 cases (37.0%). 16 cases (59.3%) showed the resorption of roots of adjacent teeth. 3. Odontoma constituting twenty-five cases (41.0%) discovered at the average age of 16.9 years and had a 3:2 male predominance. The most common complaint was delayed eruption of tooth (8 cases, 31.0%) and 7 cases (27.0%) detected on a routine radiograph of the area. Radiographically, 17 cases (68.0%) were of compound type and 8 were of complex variety and compound odontomas were common in the anterior maxilla, whereas complex odontomas occurred more frequently in the posterior mandible. 19 cases (76.0%) showed the impaction of adjacent teeth.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.41 no.5
• /
• pp.265-269
• /
• 2015

The purpose of this study was to investigate implant-supported restoration as a technique for restoring missing teeth in patients with aplastic anemia. Recurrent bleeding from wound sites leads to persistent release of iron in the tissue. Excessive iron in tissue is related to clinical findings, including fibrosis, poor wound healing, and high level of angiogenesis, which are possible etiological factors of reduced osseointegration. A 44-year-old female patient with aplastic anemia was treated with multiple endosseous implants throughout the mandible and in the posterior region of the maxilla. After 14 implants were placed, radiological and clinical parameters were assessed during the follow-up period. Marginal bone did not change significantly during the follow-up period. The fine trabecular bone in intimate contact and enclosing the implant fixture was sufficient for successful osseointegration. None of the 14 implants were associated with compilations during the seven-year experimental period. This study suggests that dental implant procedures are a safe and reliable treatment option for restoration of missing dentition in patients with aplastic anemia.

• The Journal of Korean Academy of Prosthodontics
• /
• v.42 no.4
• /
• pp.412-424
• /
• 2004

Statement of problem: Several prosthetic options are available for the restoration of multiple adjacent implants. A passively fitting prosthesis has been considered a prerequisite for the success and maintenance of osseointegration. Passivity is a particular concern with multiple implants because of documented inaccuracies in the casting and soldering process. One way to avoid this problem is to restore the implants individually, however, the restorations of individual adjacent impants requires careful adjustment of interproximal contacts. Purpose: The purpose of this study was to compare the stress distribution pattern and amount surrounding Bicon implants with individual crowns and splinted restorations. Material and method: A photoelastic model of a human partially edentulous left mandible with 3 Bicon implants($4{\times}11mm$) was fabricated. For non-splinted restorations, individual crowns were fabricated on 3 abutments ($4{\times}0.65mm,\;0^{\circ}$, 2.0 mm post, Bicon Inc., Boston, USA) After the units were cemented, 4 levels of interproximal contact tightness were evaluated: open, ideal ($8{\mu}m$ shim stock drags without tearing), medium($40{\mu}m)$), and heavy($80{\mu}m$). Splinted 3-unit fixed partial dentures were fabricated and cemented to the model. Changes in stress distribution under simulated non-loaded and loaded conditions(7.5, 15, 30 lb) were analyzed with a circular polaricope. Results: 1. Stresses were distributed around the entire body of fin in Bicon implants. 2. Splinted restorations were useful for distribution of stress around implants especially with higher loads. 3. By increasing the contact tightness between the individually restored three implants, the stress increased in the coronal portion of implants. Conclusions: Ideal adjustment of the contact tightness was important to reduce the stresses around individually restored Bicon implants.

• The Journal of Advanced Prosthodontics
• /
• v.6 no.5
• /
• pp.361-371
• /
• 2014

PURPOSE. In case of large horizontal discrepancy of alveolar ridge due to severe resorption, cantilevered crown is usually an unavoidable treatment modality. The purpose of this study was to evaluate the clinical criteria for the placement of the aforementioned implant crown. MATERIALS AND METHODS. The mandible model with 2 mm thick cortical bone and cancellous bone was fabricated from CT cross-section image. An external connection type implant was installed and cantilevered crowns with increasing offset of 3, 4, 5, 6, and 7 mm were connected. Vertical load and $30^{\circ}$ oblique load of 300 N was applied and stress around bone and implant component was analyzed. A total of 14 cases were modeled and finite element analysis was performed using COSMOS Works (Solid works Inc, USA). RESULTS. As for the location of the vertical load, the maximum stress generated on the lingual side of the implant became larger according to the increase of offset distance. When the oblique load was applied at $30^{\circ}$, the maximum stress was generated on the buccal side and its magnitude gradually decreased as the distance of the offset load increased to 5 mm. After that point, the magnitude of implant component's stress increased gradually. CONCLUSION. The results of this study suggest that for the patient with atrophied alveolar ridge following the loss of molar teeth, von-Mises stress on implant components was the lowest under the $30^{\circ}$ oblique load at the 5 mm offset point. Further studies for the various crown height and numbers of occusal points are needed to generalize the conclusion of present study.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.5 no.1
• /
• pp.64-75
• /
• 1978

In order to know cephalometric norms for the preschool children, this roentgeno cephalometric study was undertaken in each 50 Korean male and female children of primary dentition age from 4 to 5 year. The following results were obtained. 1. In the skeletal analysis, there was no significant difference between male and female in angular measurement and the linear measument of the male was generally greater than that of the female. 2. Saddle angle was $122.3^{\circ}$, articular angle was $147.6^{\circ}$, gonial angle was $119.4^{\circ}$ and the sum of each angle was $396.1^{\circ}$ in male and $396.6^{\circ}$ in female. 3. The ratio of mandibular body to anterior cranial base was about 1 : 0.91. 4. In the primary dentition, suggested that the nasion and point A move forward relative to sella turcica in a fashion, pogonion and point B are equal in angular position relative to plan S-N, bony chin and chin button was yet underdeveloped, and the forward growth of mandible was seen rapid than maxilla after 4 years. 5. Suggested that the percentage of anterior facial height to the posterior facial height were 64.4% in male and 64.1% in female. 6. Maxillary primary incisors was more upright than the permanent incisors, mandibular primary incisors was inclined lingually relative to the permanent incisor, and primary incisors was more upright than the permanent incisors. 7. Maxillary primary incisors in female was inclined labially than male. 8. In the the relationship of the upper lip and lower lip to the esthetic line, the upper lip was 2.11mm and the lower lip was 2.33mm front of the esthetic line.

• Korean Journal of Cleft Lip And Palate
• /
• v.14 no.1_2
• /
• pp.1-18
• /
• 2011

Skeletal malocclusion is the result of abnormal dimension and alignment of each skeletal component. Understanding on these mechanisms may help to elucidate the etiology of skeletal malocclusion and to establish population-oriented treatment plans. Attempts to subdivide the Angle's classification have been performed for Class III malocclusion, while few studies have been conducted for Class II malocclusion despite recent growing interests in Class II malocclusion. 200 adults (88 male, 112 female) with skeletal Class II malocclusion were collected and subdivided using cluster analysis, using the measurements representing the dimension and the alignment of each facial skeletal component. The properties of each cluster was grouped within the subjects and a comparison between the subjects and the control group (38 male, 35 female) with normal occlusion was performed. Six clusters were finally recognized in each male and female groups. The clusters in both genders were mainly characterized by the cranial base alignment, dimension of the posterior cranial base, dimension of the mandibular ramus and the degree of mandibular rotation. The results implicate that active treatment of mandible rather than the nasomaxillary complex may be primarily considered for the correction of Korean Class II skeletal pattern.

• The Journal of Korean Academy of Prosthodontics
• /
• v.54 no.2
• /
• pp.126-131
• /
• 2016

Surgical management of oral cancer results in compromised masticatory and swallowing function which affects patient in social and psychological aspects due to reduced phonetic ability and facial deformity, thus, it is imperative to provide applicable prosthetic treatment to overcome such complications. This clinical study describes rehabilitation of a patient with squamous cell carcinoma treated with marginal mandibulectomy and implantation on preserved posterior portion of mandible to provide stability and support for subsequent denture treatment. Kennedy class IV removable partial denture has provided satisfactory results in esthetics and function. Bone level stability around implants was reported to be maintained during eight months of clinical observation.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.26 no.4
• /
• pp.463-476
• /
• 2010

Inadequate or unstable posterior support cause extrusion of antagonistic teeth and overloading of remaining teeth. Extrusion of antagonistic teeth result in collapsed occlusal plane and decreased prosthetic space. Also, overloading of remaining teeth increase occlusal wear or anterior extrusion of anterior teeth, which is resulting in loss of anterior guidance, disharmony of occlusion and decreased prosthetic space. In this case, careful evaluation of OVD(occlusal vertical dimension) is the general first trial to regain appropriate function and esthetics. Simultaneously, adequate anterior guidance and harmonious occlusal plane should be established in the repeatable reference position of the mandible. We report this case because severely worn dentition achieved functional and esthetic results from full mouth rehabilitation with increased vertical dimension and use of centric relation.