Edentulous Region (edentulous + region)

Distribution by Scientific Domains


Selected Abstracts


A biomechanical effect of wide implant placement and offset placement of three implants in the posterior partially edentulous region

JOURNAL OF ORAL REHABILITATION, Issue 1 2000
Y. Sato
To prevent loosening or fracture of screws retaining the prosthesis to the implants in the posterior partially edentulous region, the use of staggered buccal and lingual offset placement or wide implants is suggested. However, it is not known how this usage compensates for the torque produced by lateral occlusal forces. This study evaluated the effectiveness of offset placement of three implants and a wide implant placement at the most posterior site. Three-dimensional geometric analysis was used to calculate the tensile force applied to gold screws in clinical situations with buccal or lingual loading perpendicular to cuspal inclination (10 or 20°). Four variations of the placement of three implants (, 3·75 mm) are: (1) straight; (2) buccal offset of the second implant; (3) lingual offset of the second implant; (4) a wide implant (, 5 mm) placement at most posterior site. The offset placement did not always decrease tensile force at the gold screw, but wide implant placement and decrease in cuspal inclination did. [source]


Perineurioma of the mandibular dental nerve: a case report and review of the literature

ORAL SURGERY, Issue 2 2009
E.F. Vencio
Abstract Perineurioma is an uncommon benign tumour of the nerve sheath composed exclusively of well-differentiated perineurial cells. It usually affects the limbs or trunk; intraoral lesions are uncommon. A rare case of perineurioma is described involving the mandibular dental nerve in a 59-year-old female, microscopically characterised by a combined pattern of intraneural and soft tissue perineurioma. The patient was referred for treatment of a lesion in the mandible. Panoramic radiography revealed a well-delimited osteolytic lesion with radiopaque halo in an edentulous region of the left mandible. Occlusal view showed no expansion of cortical bone. A surgical procedure for incisional biopsy disclosed a connection between the tumour and the alveolar inferior nerve. Grossly, an enlargement of the affected nerve was described. Microscopic examination showed tumour cells arranged in pseudo-onion bulb structures, with scattered collagen bundles, and areas with a whorled (storiform) arrangement. Many concentric whorls of spindle cells exhibiting thin, elongated eosinophic processes were seen. Immunohistochemical study exhibited strong positivity for epithelial membrane antigen. We report a rare case of perineurioma affecting the mandibular dental nerve showing both intraneural and soft tissue microscopic patterns and discuss morphological aspects for differential diagnosis. [source]


Load transfer characteristics of unilateral distal extension removable partial dentures with polyacetal resin supporting components

AUSTRALIAN DENTAL JOURNAL, Issue 1 2009
T Jiao
Abstract Background:, To photoelastically examine load transfer by unilateral distal extension removable partial dentures with supporting and retentive components made of the lower stiffness polyacetal resins. Methods:, A mandibular photoelastic model, with edentulous space distal to the right second premolar and missing the left first molar, was constructed to determine the load transmission characteristics of a unilateral distal extension base removable partial denture. Individual simulants were used for tooth structure, periodontal ligament, and alveolar bone. Three designs were fabricated: a major connector and clasps made from polyacetal resin, a metal framework as the major connector with polyacetal resin clasp and denture base, and a traditional metal framework I-bar removable partial denture. Simulated posterior bilateral and unilateral occlusal loads were applied to the removable partial dentures. Results:, Under bilateral and left side unilateral loading, the highest stress was observed adjacent to the left side posterior teeth with the polyacetal removable partial denture. The lowest stress was seen with the traditional metal framework. Unilateral loads on the right edentulous region produced similar distributed stress under the denture base with all three designs but a somewhat higher intensity with the polyacetal framework. Conclusions:, The polyacetal resin removable partial denture concentrated the highest stresses to the abutment and the bone. The traditional metal framework I-bar removable partial denture most equitably distributed force. The hybrid design that combined a metal framework and polyacetal clasp and denture base may be a viable alternative when aesthetics are of primary concern. [source]


Orthodontic and prosthetic rehabilitation of unilateral free-end edentulous space

AUSTRALIAN DENTAL JOURNAL, Issue 4 2006
SG Arslan
Abstract Most patients prefer fixed dentures, even in the presence of uni and bilateral free-end saddle. The most suitable treatment for this is an implant or implant-supported prosthetic restoration. A combined prosthetic and orthodontic treatment with distalization of a posterior tooth towards the edentulous region is an alternative approach. This study involved a 34.3 year old female patient who had a free-end edentulous space on the left mandibula and missing 1st and 3rd molars on the right mandibula. The patient was offered both a removable partial denture and implant treatment options. A detailed explanation of her situation and suitable treatments were given but she refused both options. Therefore, an alternative combined treatment involving prosthodontic and orthodontic disciplines was performed. The second premolar tooth was distalized orthodontically and used as a distal bridge abutment. After 65 months, prosthetic restoration was functional and abutment teeth and periodontium were pathology free, and the patient was satisfied with the results. [source]