• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.442-450
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• 2021

The CAD-CAM technique is a rapidly developing field in the dental field and is applied to various fields of prosthetic treatment. Among them, the manufacturing of dentures using the milling technique classified as subtractive manufacturing is one of the commercialized digital full denture manufacturing methods. At the same time, it is possible to more efficiently manufacture a metal framework for implant overdenture by selective laser sintering or melting technique classified as an additive manufacturing method. The purpose of this article is to describe the fabrication of CAD-CAM maxillary complete denture and mandibular implant overdenture as well as its features.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.347-353
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• 2022

Traditional denture treatment is often performed in patients with the completely edentulous maxilla and the bilateral edentulous posterior mandible. However, with a long-term prognosis, a complication called 'combination syndrome' may occur in this oral environment. In this case, by applying an implant-assisted removable partial denture (IARPD), it is possible to preserve the alveolar bone and prevent combination syndrome. In this case, when additional implants are placed in the edentulous area, the stress applied to the abutment due to the movement of the removable denture can be reduced, so it is possible to design an esthetic clasp using resin rather than metal, and flexible denture base resin is used. As a treatment for maxillary complete denture and mandibular flexible IARPD, it showed an esthetic and functional long-term prognosis with minimal cost and surgery.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.2
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• pp.173-178
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• 2018

The direct metal laser sintering (DMLS) technique would be promising for the full-arch implant-supported restorations due to reduced cost and manufacturing time without potential human errors and casting defects. The aims of this case report were to describe the successful outcome of an implant-supported fixed dental prosthesis in the edentulous maxilla by using the DMLS technology and computer-aided design and computer-aided manufacturing (CAD/CAM) monolithic zirconia crowns, and to describe its clinical implications. A healthy 51-year-old Korean woman visited Seoul National University Dental Hospital and she was in need of a rehabilitation of her entire maxilla due to severe tooth mobility. In this case, all maxillary teeth were extracted and an implant-supported fixed dental prosthesis was fabricated that involved a cobalt-chromium (Co-Cr) framework with the DMLS technique and CAD/CAM monolithic zirconia crowns. Six months after delivery, no distinct mechanical and biological complications were detected and the prosthesis exhibited satisfactory esthetics and function. In this case report, with the DMLS system, the three-dimensional printed prosthesis was created without additional manual tooling and thus, reliable accuracy and passive fit were obtained.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.356-363
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• 2019

A patient who went through maxillectomy can have soft palate defects including oronasal fistulas and suffer from dysphagia and dysarthria due to velopharyngeal insufficiency. This defect causes the food to enter nasal cavity and creates hypernasal sound which debilitates a quality of life. An obturator can rehabilitate the substantial oral tissue defects. The maxillary obturator separates the nasopharynx from the oropharynx during speech and deglutition by closing of the defect. For edentulous obturator patient, it is difficult to obtain proper retention due to reduced peripheral sealing. Therefore, the contours of the defects must be used to maximize the retention, stability, and support. Hollow type obturator can improve physiologic function by reducing weight than the traditional obturator. This case report describes a patient with hemi-maxillectomy who recovers mastication, speech, deglutition, and appearance with a maxillary obturator using physiological border molding of the velopharyngeal area and double-processing method.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.281-293
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• 2021

Patients who went through maxillectomy can have severely impaired swallowing, mastication, and pronunciation functions because of palatal defects. Leakage occurs through the nasal cavity while eating, chewing becomes difficult due to the loss of teeth and alveolar ridges, and oral and nasal passages are not separated, leading to hyper-nasal sound, and significantly reducing the quality of life. To prosthetically reconstruct the defect, the weight of the obturator should be reduced as much as possible to minimize dropout because of gravity, and the bulb of the obturator should be properly extended into the defect to get additional retention and stability. In this case of a partially edentulous patient who underwent additional maxillary resection because of tumor recurrence, a metal framework was designed by applying the basic design principles of removable partial dentures. An obturator with improved retention, stability, and support was fabricated through functional impressions. The patient was satisfied with the improved facial expression, mastication, swallowing, and pronunciation, and showed stable occlusion and oral hygiene management during the follow-up period.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.277-290
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• 2012

Dental implants are universal restorative method on edentulous site in oral cavity and generally recognized by patients as well as clinicians. Rapid bone resorption of labial portion of maxillary anterior area is performed due to dental trauma, chronic periodontitis, and so on. Accordingly, Implants on maxillary anterior alveolar ridge with narrow labiopalatal width would lead to bony defects of dehiscence or fenestration. In this case, guided bone regeneration procedure is used to augment maxillary anterior alveolar ridge. It can have mechanical and biological advantages to mix tissue adhesive with bone graft materials in guided bone regeneration procedure. In these cases, when the dehiscence or fenestration defects was occurred by dental implants on maxillary anterior alveolar ridge with narrow labiopalatal width, guided bone regeneration procedures were performed with various combination of particle bone graft materials(allograft, xenograft, and alloplast) mixed with fibrin glue, excepting autogerous bone. We reported that all of 4 cases showed favorable alveolar ridge augmentations.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.3
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• pp.193-200
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• 2020

Purpose: To investigate the relationship between dementia and complete tooth loss on both sides or one side using large demographic data. Materials and methods: A retrospective cohort study was designed using the National Health Insurance Service-Elderly Cohort Database (NHIS-ECD) which was established for people over the age of 60. The experimental group was the complete edentulous cohort, which had a history of treatment for national health insurance covered complete denture on both sides or one side from July 1, 2012 to December 31, 2013. And the control group was the dentulous cohort, which had a history of conservative dental treatment for the same period. All subjects had no history of diagnosis or treatment of dementia during this time. These cohorts were matched 1:1 by age, gender, and place of residence according to the propensity score matching method. Then the incidence of dementia was compared between these cohorts. Results: Compared with those groups, the incidence of dementia was significantly higher in the experimental group (12.13%) than in the control group (9.74%) (P<.05). No clear association between other factors has been identified. Conclusion: The analysis of large-scale demographic data shows that the incidence of dementia is high in complete edentulous patients on both sides or one side.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.497-507
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• 2021

All-on-six concept can be used as one of the treatment options to maximize the use of available residual alveolar bone for implant-supported fixed prosthesis on edentulous patients. But this process is complex and cumbersome. Digital system can be used at multiple steps, from implantation to prosthetic restoration, to overcome this shortcoming. In this case of a maxillary edentulous patient aged 76, digital system was used for restoration of 1-piece design, screw retained fixed prosthesis from diagnosis, implant surgery to fabrication of provisional and final prosthesis. For preoperative diagnosis and treatment planning stage, intra-oral information of a patient was digitalized by direct intra-oral scan. Surgical guide and immediate provisional prosthesis was designed based on this digitalized data. Patient's inconvenience was minimized by applying immediate provisional prosthesis, which was delicately fabricated according to the location data of six implants on most suitable residual alveolar bone. Then, final prosthesis was designed and fabricated going through new interim prosthesis which was newly designed and fabricated, considering patient's requests, stable vertical dimension and occlusion, and esthetic factors using digital system. We hereby report a case successfully applying digital system to multiple steps including implant surgery to fabricating prosthesis, to simplify existing complicated implant treatment procedure to an edentulous patient.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.310-317
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• 2015

Purpose: The purpose of this study was to evaluate the validity of reference points for edentulous patient by examining the correlation of teeth and face, and intraoral anatomic landmarks. Materials and methods: We examined a facial outline, length, bizygomatic width, nasion - gnathion length, glabella - nasion distance in 270 men and 280 women satisfied with inclusion criteria from Seoul National School of Dentistry. The shape of maxillary central incisor, mesiodistal crown width and length of maxillary 6 incisors, distance from incisive papilla to labial surface of maxillary central incisor, and perpendicular distance from incisive papilla to intercanine line were measured in the stone model. We analyzed the ratio and relevant relation statistically. Results: The probability on having the same shape of face and the relative same shape maxillary incisor was 55.56% and 46.43% for men and women. The facial length proved to be a more valuable measurement in women in the tooth selection. The ratio of bizygomatic width to mesiodistal width of maxillary central incisor, and the ratio of bizygomatic width to width of maxillary 6 incisors were 16.8 : 1 and 3.0 : 1 and were positively correlated with each other. The distance of the canines from the maxillary incisal papilla was $1.33{\pm}1.28mm$. The distance between the center of the incisal papilla and the labial surface of their maxillary central incisor was $9.23{\pm}1.20mm$. Conclusion: It was showed that anatomical reference points in tooth selection and arrangement for edentulous patient are useful and have validity in our limited study.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.2
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• pp.180-186
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• 2017

Implant supported prostheses have improved the quality of lives of totally edentulous patients. However, there are some limitations on the number of implants related to the residual bone level or the economic concern and so on. In this situation, applying fixed detachable prosthesis with bilateral cantilevers can be considered. This clinical report describes implant supported prosthetic rehabilitation of a patient with severe bone resorption. The patient was satisfied and felt comfortable with upper complete denture and lower fixed detachable prosthesis.