• Imaging Science in Dentistry
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• v.31 no.3
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• pp.165-173
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• 2001

Objectives : To evaluate the absorbed and effective doses of spiral and computed tomography for the dental implant planning. Materials and Methods: For radiographic projection, TLD chips were placed in 22 sites of humanoid phantom to record the exposure to skin and the mean absorbed dose to bone marrow, thyroid, pituitary, parotid and submandibular glands and nesophagus. Effective dose was calculated, using the method suggested by Frederiksen et al.. Patient situations of a single tooth gap in upper and lower midline region, edentulous maxilla and mandible were simulated for spiral tomography. 35 axial slices (maxilla) and 40 axial slices (mandible) with low and standard dose setting were used for computed tomography. All the radiographic procedures were repeated three times. Results: The mean effective dose in case of maxilla was 0.865 mSv, 0.452 mSv, 0.136 mSv and 0.025 mSv, in spiral tomography of complete edentulous maxilla, computed tomography with standard mAs, computed tomography with low mAs and spiral tomography of a single tooth gap (p<0.05). That in case of mandible was 0.614 mSv, 0.448 mSv, 0.137 mSv and 0.036 mSv, in spiral tomography of complete edentulous mandible, computed tomography with standard mAs, computed tomography with low mAs and spiral tomography of a single tooth gap (p<0.05). Conclusions: Based on these results, it can be concluded that low mAs computed tomography is recommended instead of spiral tomography for the complete edentulous maxilla and mandible dental implant treatment planning.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.2
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• pp.152-159
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• 2016

Implant fixed prosthesis for the complete edentulous maxilla provides significant benefits in the aspects of functions and esthetics compared with the conventional denture. Implant supported fixed prosthesis are totally supported by implant, and thus stabilizes the prosthesis to the maximum degree as possible. Also, the improved retention and stability of fixed prosthesis enhance patients' psychological and psychosocial health. This clinical presentation describes a maxillary full arch implant-supported fixed prosthesis in complete maxillary edentulous patient who showed vertical and horizontal alveolar bone resorption in the anterior ridge. To rehabilitate the esthetics and proper lip support, the zirconia framework was fabricated and the pink porcelain was veneered to reproduce the natural gingival tissue. After 9 months of follow up, the restorations were maintained without complications and the patient was satisfied with the restoration both functionally and esthetically.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.6
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• pp.634-638
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• 2008

PURPOSE: The application of computer-aided technology to implant dentistry has created new opportunities for treatment planning, surgery and prosthodontic treatment, but the correct selection and combination of available methods may be challenging in times. Hence, the purpose of this case report is to present a combination of several computer-aided tools as approaches to manage complicated implant case. MATERIAL AND METHODS: A 47 year-old female patient with severe dental anxiety, high expectations, financial restrictions and poor compliance presented for a fixed rehabilitation. A CT scan with a radiographic template obtained with software (SimPlant, Materialize, Leuven, Belgium) was used for treatment planning. The surgical plan was created and converted into a stereolithographic model of the maxilla with bone-supported surgical templates (SurgiGuide, Materialise, Leuven, Belgium), that allowed for the precise placement of 7 implants in a severely resorbed edentulous maxilla. After successful osseointegration, an accurate scan model served as the basis for the fabrication of a one-piece milled titanium framework using the Procera (Nobel Biocare, Gothenburg, Sweden) technology. The final rehabilitation of the edentulous maxilla was rendered in the form of a screw-retained maxillary metal-reinforced resin-based complete prosthesis. RESULTS: Despite challenging circumstances, 7 implants could be placed without bone augmentation in a severely resorbed maxilla using the SimPlant software for pre-implant analysis and the SurgiGuide-system as the surgical template. The patient was successfully restored with a fixed full arch restoration, utilizing the Procera system for the fabrication of a milled titanium framework.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.1
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• pp.25-30
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• 2018

In edentulous patients, the advantages of prosthodontic therapy using oral implants include both stability and comfort. Advantages suggested for this approach include the prevention of mandibular bone resorption and increased masticatory function. Implant hybrid prostheses place 4 to 6 implants between the mental foramens, and cantilevers are used to replace the posterior teeth at both ends. The 85 - year - old female patient visited our clinic with complete edentulism in the maxilla and mandible. This article reports a satisfactory clinical and esthetic outcome of full mouth rehabilitation using removable complete denture in the maxilla and implant hybrid prosthesis in the mandible.

• The Journal of Advanced Prosthodontics
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• v.6 no.1
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• pp.53-59
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• 2014

PURPOSE. The aim of this study was to obtain statistical data on the residual bone height at different natural tooth positions by panoramic radiography in edentulous Korean patients aged 60-90 years. MATERIALS AND METHODS. The study included the diagnostic panoramic radiographs of 180 randomly selected edentulous patients without systemic diseases affecting bone. The radiographic selection criteria included absence of obvious facial asymmetry, clearly visible anatomic structures, and no surgical and fracture history. The panoramic radiographs of 79 patients met these criteria and were used in the analysis. The same researcher processed all the radiographs by using a standardized method. The height of the residual bone was measured at 18 predetermined sites (7 in the maxilla and 11 in the mandible) on digitized and printed radiographs by using a Digimatic caliper, triangle, and ruler. Gender- and age-related differences were statistically analyzed by using the t-test and rank-sum test (${\alpha}=0.05$). RESULTS. The maxillary residual bone height did not show significant gender-related differences, but male patients had significantly higher residual bone in the mandible(P<.05). No significant height differences at the measured sites were noted among the 60s, 70s, and 80s age groups. CONCLUSION. Dentists should pay greater attention to older female edentulous patients because they are more prone to rapid residual bone resorption. Residual bone resorption may not be affected by age.

• The Journal of Advanced Prosthodontics
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• v.4 no.4
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• pp.254-258
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• 2012

Implant-supported overdenture is a reliable treatment option for the patients with edentulous mandible when they have difficulty in using complete dentures. Several options have been used for implant-supported overdenture attachments. Among these, bar attachment system has greater retention and better maintainability than others. SFI-Bar$^{(R)}$ is prefabricated and can be adjustable at chairside. Therefore, laboratory procedures such as soldering and welding are unnecessary, which leads to fewer errors and lower costs. A 67-year-old female patient presented, complaining of mobility of lower anterior teeth with old denture. She had been wearing complete denture in the maxilla and removable partial denture in the mandible with severe bone loss. After extracting the teeth, two implants were placed in front of mental foramen, and SFI-Bar$^{(R)}$ was connected. A tube bar was seated to two adapters through large ball joints and fixation screws, connecting each implant. The length of the tube bar was adjusted according to inter-implant distance. Then, a female part was attached to the bar beneath the new denture. This clinical report describes two-implant-supported overdenture using the SFI-Bar$^{(R)}$ system in a mandibular edentulous patient.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.4
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• pp.397-406
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• 2012

Loss of tooth results in remodeling and resorption of surrounding alveolar bone which causes atrophic edentulous ridge and gradually decreasing gingival attachment. As a result, edentulous patients face difficulty in using dentures due to pain, decrease of support, decline of masticatory efficiency of complete denture. To improve this, overdenture with implant in the mandible and attachment are considered as a treatment of choice as a favorable treatment. In this case, a patient with edentulous ridge for long period is rehabilitated by complete denture in maxilla and implant overdenture using Locator$^{(R)}$ attachment in mandible.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.55-62
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• 2021

The mandible has a smaller support area than the maxilla, and in particular, in patients with generalized alveolar bone resorption, the stability of the denture and the masticatory efficiency are significantly low in the case of conventional complete denture, due to the movement of the tongue and mandible. In these patients, implant overdenture is evaluated as a highly predictable treatment method with high retention and stability, and excellent pronunciation and masticatory force. In this clinical case, patient had an edentulous maxilla and generalized alveolar bone resorption in mandible. Therefore, complete denture was placed in the maxilla and implant overdenture using milled bar attachment on 4 implants was placed in the mandible. During the 12-year follow-up period, changes in periodontal tissue and denture around the implants were periodically managed and observed.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.222-228
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• 2011

Purpose: The purposes of this study were to evaluate the stress distributions and the displacements of obturator for edentulous maxillectomy patients and to compare them with those of complete denture using three-dimensional finite element analysis. Materials and methods: Based on the CT image of edentulous patient, three-dimensional finite element model of edentulous maxillae was constructed. Three-dimensional finite element model of edentulous maxillae with palatal defect was also fabricated. On each model, complete denture and obturator prosthesis were created. Vertical static force of 200 N was applied on the left maxillary premolar and molar region. The von Mises stress values and the displacements of models were analyzed using three-dimensional finite element analysis. Results: Maximum von Mises stress values were recorded in the cortical bones of both models. The von Mises stress value in the complete denture model was 2.73 MPa and 2.69 MPa in the obturator model. High von Mises stress values were also observed on the tissue surface of prosthesis. The maximum value of the displacement in the obturator was higher than that of complete denture. Conclusion: The obturator showed a worse result in terms of stress distribution and displacement than complete denture. In the prosthodontic rehabilitation of edentulous maxillectomy patient accurate impression procedure based on patients'anatomy and application of prosthodontic principle should be considered.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.4
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• pp.346-351
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• 2014

Suction dentures enhance retention and support by forming negative pressure temporarily at the internal surface of denture base at times of swallowing and chewing because the areas surrounding the denture flanges are sealed by mobile mucosa. In this case, an 81-year-old male visited for new dentures. Considering the high expectations for retention and masticatory efficiency of dentures, fabricating complete dentures with suction dentures was planned. Preliminary impression was taken without applying pressure on retromolar pad area and diagnostic cast was fabricated. Afterwards, individual tray was made and final impression was taken, at the same time, gothic arch tracing was done to acquire centric relation and vertical dimension. Then, anatomic teeth were placed on maxilla and non-anatomic teeth were placed on mandible forming lingualized occlusion. Consequently, restoring a complete edentulous patient with complete dentures using mandibular suction denture resulted in recovering satisfying retention and function.