STATEMENT OF PROBLEM: The position and length of cantilever influence on the stress distribution of implants, superstructure and bone. In edentulous mandible, implant-supported cantilever prostheses that based 4 or 6 implants between mental foramens has been attempted. Excessive bite force loaded at cantilever prosthesis causes bone resorption and breakage of superstructure prosthesis around posterior implants. To complement the cantilever length of conventional prosthesis, In 1992, (McCartney) introduced "cantilever - rest - implant" and Malo reported "All-on-Four" in 2003. PURPOSE: Analyze and compare the stress distribution of conventional cantilever prostheses with rest implant and Allon-Four(TM) implant prostheses. MATERIAL AND METHOD: The external loads (300 N vertically, 75 N horizontally) are applied to first molar area. The stress value, stress distribution and aspect of stress dispersion are analyzed by three-dimensional finite element analysis program, ANSYS ver. 10.0. RESULTS: 1. The rest implant and "All-on-Four" implant system are superior to conventional cantilever prostheses to reduce stress on the bone and the superstructure around implants. 2. The rest implant was of the greatest advantage to stress distribution on bone, implant and superstructure. 3. With same number of implants, distally tilted implants are preferred to conventional cantilever prostheses for reducing the length of cantilever.
Bite Force ; Bone Resorption ; Complement System Proteins ; Finite Element Analysis ; Imidazoles ; Mandible ; Molar ; Nitro Compounds ; Prostheses and Implants

Actinomycosis is a rare form of disease that is caused by Actinomyces such as A. israelii and A. bovis, which may take the form of chronic, purulent inflammation of deep tissue evolves with necrosis, formation of sinuses and fibrotic mass. This disease arises in the head and neck area mainly in 55% and other places like that chest and the gastrointestinal tract occurs in 45%. Actinomycosis can present in a variety of forms and may mimic other infections or even neoplasms. Our case was 44-year-old man having painful indurated mass in his left TMJ area, otorrhea in his left ear and trismus. He was treated with surgical excision and biopsy confirmed actinomycosis. And after that, he was cured successfully with antibiotic therapy. We report this case of actinomycosis that developed in the left TMJ area with review articles.
Actinomyces ; Actinomycosis* ; Adult ; Biopsy ; Ear ; Gastrointestinal Tract ; Head ; Humans ; Inflammation ; Neck ; Necrosis ; Temporomandibular Joint* ; Thorax ; Trismus

Bicuspid ; Dentigerous Cyst ; Enamel Organ ; Jaw ; Molar, Third ; Mouth ; Odontogenic Cysts ; Tooth ; Tooth Crown