THE THREE DIMENSIONAL FINITE ELEMENT ANALYSIS OF STRESS DISTRIBUTION AND DISPLACEMENT IN MANDIBLE ACCORDING TO TREATMENT MODALITIES OF MANDIBULAR ANGLE FRACTURES

Morphometric analysis on bone formation effect of beta-TCP and rhBMP-2 in rabbit mandible

INTRODUCTION: This study was to assess the effectiveness of new bone formation and regeneration by using a rhBMP-2 and beta-TCP as a carrier in rabbits' mandible. MATERIALS AND METHODS: The mandibles of 36 rabbits were exposed and cortical bone was penetrated for this study. The experimental subjects were divided into 3 groups each 12 rabbits; control group, experimental group 1, and experimental group 2. Control group had the defect itself without any treatment, in the experimental group 1, beta-TCP only was grafted, and in the experimental group 2, rhBMP-2 soaked in beta-TCP was grafted. The rabbits were sacrificed after 1, 2, 3, 4, 6, and 8weeks, and new bone formation area was examined and measured for bone quantitative and qualitative analysis with light, fluorescent and polarized microscopy. RESULTS: In the experimental group 1, new bone formation from the adjacent host bone was made by osteoconduction, and in the experimental group 2, direct new bone formation by osteoinduction of rhBMP-2 as well as new bone formation by osteoconduction of beta-TCP were observed. CONCLUSION: rhBMP-2 of experimental group 2 is very effective in the bone formation in early 2weeks and bone remodelling from 3weeks.

Oral Pemphigus Vulgaris: A Case Report

Kaposi's sarcoma of maxillary gingiva in systemic lupus erythematosus

A Clinical Study of Biodegradable Plates and Screws in Oral and Maxillofacial Surgery

Metallic bone plates and screws have been commonly used in oral and maxillofacial surgery for internal fixation. However, there are several disadvantages such as atrophy of cortical bone inherent to excessive rigid fixation systems, growth disturbance in growing individual, allergy reaction, interference with radiographic imaging, palpability, thermal sensitibity and the need for subsequent removal. To overcome these disadvantages and avoid additional surgery of removal of plates and screws, there have been many studies of biodegradable plates and screws. But, It also has complication such as foreign body reactions. We have undertaken a clinical and retrospective study on 140 patients in Dept. of Oral and Maxillofacial Surgery, Inha University Hospital from February 2006 to March 2009. The purpose of this study is to report the clinical cases and review of the literatures with biodegradable plates and screws. And we concluded following results. 1. 6 cases(3.4%) of the 177 operation sites(140 patients) experienced complications. 1 case(0.6%) was a failure of initial fixation, 1 case(0.6%) was a postoperative infection, 4 cases(2.3%) were inflammations or foreign body reaction. 2. Postoperative infections, inflammations and foreign body reactions were completely recovered with incision and drainage, supporative care with antibiotic coverage and removal of biodegradable plates. 3. Biodegradable plates and screws provide acceptable rigidity and stability clinically. But, long-term observation is required for the tissue reactions around the biodegradable plates and screws because of long resorption periods of the biodegradable materials.