• The Journal of Korean Academy of Prosthodontics
• /
• v.43 no.2
• /
• pp.191-203
• /
• 2005

Statement of problem. In Korea, the preliminary impression trays for dental and edentulous maxillae are manufactured on the base of the statistical value of Westerners. There had been less study on the dental and edentulous arches of Koreans. Purpose. The purpose of this study was to evaluate an average dental cast, preliminary impression trays, three-dimensional relation of dental and edentulous maxilla of Koreans Material and methods. The subjects for this study were 173 dental casts of maxilla (dental: 52, edentulous : 146) with ages $18\{\sim}60$ years old. Each of the master casts was measured 69 measuring points on the dental cast or maxilla, and 46 measuring points on the edentulous cast of maxilla with three-dimensional digital measuring machine. Each measuring points were analysed and were overlapped, that three dimensional dental graphic manufactured by CAD/CAM system. Results. 1. A standard of distribution to alveolar bone were width between left and right buccal border lines of the standard 3/4 line. The mean value of dental and edentulous casts were 67.27mm, 63.49mm respectively. 2. Morphological classification of dental casts were divided into three groups or V-shape, O-shape, U-shape, that proportion of distribution were 17%, 16%, 67%, respectively. Dimensional classification of the dental casts were divided into five groups of less than 63mm, 63 up to 65mm, 65 up to 67mm. 67 up to 69mm, more than 69mm, respectively. 3. Morphological classification of edentulous casts were divided into three groups or V-shape, O-shape, U-shape, that proportion of distribution were 18%, 17%, 65%, respectively Dimensional classification of the edentulous casts were divided into five groups of less than 57mm, 57 up to 61mm, 61 up to 65mm, 65 up to 69mm, more than 69mm, respectively. 4. Mean dental and edentulous cast of maxilla were overlapped, the proportion of bone resorption to alveolar bone is higher than that of palatal bone, its difference were higher anterior 2/4 area than posterior 3/4 area. Conclusion. It obtains information of preliminary impression trays for dental and edentulous maxilla of Koreans.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.22 no.2
• /
• pp.259-269
• /
• 1992

The author has examined the abnormalities in panoramic radiographs of 668 edentulous patients. The distribution, type, incidence, and location of all abnormalities were analized, and the distances between alveolar crest and anatomical structures were measures. (Maxillary measurements were performed between alveolar crest and lower margin of the maxillary sinus and mandibular measurements between alveolar crest and upper edge of the mental foramen.) The obtained results were as follows: 1. Of the 668 panoramic radiographs examined, 103(15.4%) showed one or more abnormalities. 2. The incidence of abnormalities was decreased by years, which was 22.0% in 1970's and 16.8% in 1980's and 12.1 % in 1990's. 3. The distribution of abnormalities as follows; 43 (40.2%) superficial root fragments, 24(22.4%) impacted teeth, 9(8.4%) imbedded root fragments, 7 (6.5%) cysts, 7(6.5%) fractures, 5(4.7%) foreign bodies, 5(4.7%) abnormal radiolucencies, 4(3.7%) abnormal radiopacities, 2(1.9%) bony defects, 1(0.9%) tumor. 4. In the location of abnormalities, 42 cases (35.3%) were in the maxillary posterior region, 26 cases(21.8%) were in the maxillary anterior region, 20 cases(24.4%) were in the mandibular posterior region and 18 cases(15.1%) were in the mandibular anterior region. 5. In the distance between alveolar crest and maxillary sinus, 109 cases(9.7%) were below 0.5㎜, 757 cases(67.6%) were between 0.5㎜ and 10㎜, 254 cases(22.7%) were above 10㎜. In the distance between alveolar crest and mental foramen, 73 cases (8.8%) were below 0.5㎜, 501 cases (60.7%) were between 0.5㎜ and l0㎜ and 252 cases(30.5%) were above 100㎜.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.21 no.2
• /
• pp.189-197
• /
• 1999

The use of osseointegrated implant has been reported that is an acceptable procedure for the restoration of totally or partially edentulous patient and that offers good predictability of long term success. It is difficult to get high success rate in edentulous maxillae with inadequate bony quality and quantity, and anatomic limitations such as pneumatic maxillary sinus and nasal floor. The various trials such as sinus lifting, bone grafting, guided bone regeneration, trabecular condensation with osteotome, and the use of wide-diameter implant have been introduced to solve these problems. This study was undertaken to assess the evaluation of clinical prognosis of the implant restorations with these various implantation techniques in the maxillary edentulous area. One hundred eight patients were treated with a total of 386 endosseous implants from March 1994 to January 1998 at Dept. of Dentistry, Korea Veterans Hospital in Seoul Korea. The various techniques for implantation in the edentulous maxillae were supplied to overcome the limitations of implant fixation. These techniques consist of sinus lifting, guided bone regeneration, onlay bone grafting, and osteotome trabecular condensation technique. The total success rate of implant restoration of this study was 93% in the maxillae. The success rate of implant restorations with conventional technique was 94.6%, with osteotome trabecular condensation technique was 94.1%, with guided bone regeneration technique was 93.3%, with bone grafting technique was 92.9%, with sinus lifting technique was 83.8%. The success rate on the maxillary anterior area was 95.2% and that on the posterior area was 91.9%. The failures were associated not only with surgical installation techniques but also bony quality and quantity, characteristics of implant, and stress distribution when in function.

• The Journal of the Korean dental association
• /
• v.37 no.4 s.359
• /
• pp.279-286
• /
• 1999

In patients with severely atrophic mandibular posterior area, implant placement is a problematic surgical procedure. Inferior alveolar nerve transpositioning technique offers better initial stability of implant and reduce the risk of permanent nerve damages. In this case report, the patient has bilateral atrophic mandibular posterior edentulous area. We placed 3 implants on each mandibular posterior area in conjunction with bilateral inferior alveolar nerve transpositioning to achieve sufficient bone height. The patient complained of paresthesia in lower lip and chin area and ptosis of lower lip after surgery. Neurosensory function was normal in 10 weeks after surgery.

• The Journal of Korean Academy of Prosthodontics
• /
• v.56 no.1
• /
• pp.25-30
• /
• 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 the Korean dental association
• /
• v.55 no.12
• /
• pp.842-849
• /
• 2017

The term, 'crossed occlusion' implies clinical situation in which the residual teeth in one arch have no contact with those in the antagonistic arch, resulting in the collapse of occlusal vertical dimension. The treatment goal of this pathologic condition is restoration of the collapsed vertical dimension and stabilization of abnormal mandibular position. Previously, konus removable prostheses or tooth supported overdentures were suggested to solve crossed occlusion. Nowadays, dental implants have been used for definitive support to solve this problem. In this case report, a 65 years old female patient had a crossed occlusion, in which the maxillary posterior residual teeth and mandibular anterior residual teeth cross. Interim removable and fixed dental prostheses were used to confirm the proper vertical and horizontal jaw relation. After that, the mandibular posterior edentulous region was restored with implant-supported fixed dental prostheses. Computer tomography guided implant surgery was performed according to the concept of the restoration-driven implant placement. The maxillary anterior edentulous region was restored with Kennedy class IV removable prosthesis, considering the patient's economic status. The patient's jaw position and prostheses have been well maintained at the follow-up after 6 months of definitive restoration. The antero-posterior crossed occlusion problems appeared to be effectively solved with the combination of removable in one arch and implant-supported fixed prostheses in the other.

• Imaging Science in Dentistry
• /
• v.37 no.3
• /
• pp.133-138
• /
• 2007

Purpose: The purpose of this study was to evaluate the morphologic features of posterior edentulous mandible for Korean patients using cross-sectional CT images. Materials and Methods: Computed tomographic cross-sectional views taken in 2004 and 2005 at Seoul National University Dental Hospital were analyzed by an oral and maxillofacial radiologist. Four indices were measured to meet the purpose of this study: 1) the horizontal distance between the alveolar crest and mandibular canal (Type), 2) the angle of the mandibular long axis (Angle), 3) the bucco-lingual location of mandibular canal, and 4) the depth of the submandibular fossa. The averages and standard deviations of the measurements were compared according to the location (the first and second molar area) and sex of the patients. Results: Statistically significant difference was found in Type, Angle, and submandibular fossa depth between the first and second molar area (p<0.05). However, there was no significant difference between men and women in any of the measured indices. Most of the mandibular canals were located in lingual side of posterior mandible. Conclusion: More care should be taken when an implant is installed on the mandibular second molar area.

• The Journal of Korean Academy of Prosthodontics
• /
• v.57 no.2
• /
• pp.176-181
• /
• 2019

Traditional removable partial denture is a successful treatment for partial edentulous patients. When the abutment is formed with unilateral minority teeth, satisfaction with the use of removable partial denture may be lowered due to patient's discomfort and damage of the abutment. Recently, it has been reported that the unilateral posterior extension partial denture is used as a bilateral posterior extension partial denture using implant fixed prostheses as abutments. In this case, by using implant surveyed crown prostheses, bilateral posterior extension partial denture is fabricated in site that is predicted to have a poor prognosis. This resulted in improved support, maintenance, and stabilization of the removable partial denture, which were economically beneficial to patient and satisfied with use.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.20 no.2
• /
• pp.166-172
• /
• 1998

Missing of the upper posterior dentition can cause alveolar bone resorption & pneumatization of Maxillary sinus wall, which makes traditional implant placement impossible, The solution includes various methods to the posterior maxilla to provide adequate bone support for implant installation and long-term survival. -- sinus floor elevation, sinus-lift graft, inlay graft using LeFort I osteotomy, onlay graft, This is a clinical Sr. retrospective study on implant surgery & prosthodontic restoration with upper edentulous posterior jaw from Jan. 1990. to Jun. 1997 at implant clinic of Chonbuk National University Hospital. The results obtained were as follows: 1. Six hundred ninety-nine implants were placed on upper posterior jaw of two hundred seventeen patients, among them one hundred sixty-five implants were placed in forty-four patients with sinus lift. 2. The height of the remained alveolar bone was classified on the base of Misch's concept. This included seventy-nine SA-1s, ninety-seven SA-2s, sixty-five SA-3s and sixty SA-4s. 3. Ninety percent of implants were successfully integrated in non-grafted area and eighty-seven percent of implants were successully integrated in sinus lift area.

• The Journal of Advanced Prosthodontics
• /
• v.11 no.2
• /
• pp.112-119
• /
• 2019

PURPOSE. Zirconia materials have been used for implant-retained restorations, but the stress distribution of zirconia is not entirely clear. The aim of this study is to evaluate the stress distribution and risky areas caused by the different design of zirconia restorations on the atrophic bone of the posterior maxilla. MATERIALS AND METHODS. An edentulous D4-type bone model was prepared from radiography of an atrophic posterior maxilla. Monolithic zirconia and zirconia-fused porcelain implant-retained restorations were designed as splinted or non-splinted. 300-N occlusal forces were applied obliquely. Stress analyses were performed using a 3D FEA program. RESULTS. According to stress analysis, the bone between the 1) molar implant and the 2) premolar in the non-splinted monolithic zirconia restoration model was stated as the riskiest area. Similarly, the maximum von Mises stress value was detected on the bone of the non-splinted monolithic zirconia models. CONCLUSION. Splinting of implant-retained restorations can be more critical for monolithic zirconia than zirconia fused to porcelain for the longevity of the bone.