Spontaneous bone regeneration after enucleation of jaw cysts: a comparative study of panoramic radiography and computed tomography

INTRODUCTION: A cyst is a closed pathologic sac containing fluid or semi-solid material in central region. The most common conventional treatment for a cyst is enucleation. It was reported that spontaneous bone healing could be accomplished without bone grafting. We are trying to evaluate bone reconstruction ability by analyzing panorama radiograph and computed tomography (CT) scan with retrograde studying after cyst enucleation. In this way we are estimating critical size defect for spontaneous healing without bone graft. MATERIALS AND METHODS: The study comprised of 45 patients who were diagnosed as cysts and implemented enucleation treatment without bone graft. After radiograph photo taking ante and post surgery for 6, 12, 18, 24 months, the healing surface and volumetric changes were calculated. RESULTS: 1. Spontaneous bone healing was accomplished clinically satisfying 12 months later after surgery. But analyzing CT scan, defect volume changes indicate 79.24% which imply incomplete bone healing of defect area. 2. Comparing volume changes of defect area of CT scan, there are statistical significance between under 5,000 mm3 and over 5,000 mm3. The defect volume of 5,000 mm3 shows 2.79x1.91 cm in panoramic view. CONCLUSION: Bone defects, which are determined by a healed section using a panoramic view, compared to CT scans which do not show up. Also we can estimate the critical size of defects for complete healing.

Panoramic analysis about spontaneous bone regeneration after enucleation of jaw cyst

Spontaneous Bone Regeneration in Surgically Induced Bone Defects in Young Rabbits / 대한정형외과학회잡지

PURPOSE: To evaluate and compare the spontaneous regeneration repair process in femoral bone defects in 6-week-old rabbits and to compare the healing time periods between different rabbit groups. MATERIALS AND METHODS: Bone defects were created at the femur mid-shaft and an external fixator was applied in 50 rabbits. The periosteum was resected in 10 rabbits (defect size: 15%, 25%) and left untouched in the remaining rabbits. Forty rabbits were divided into four groups according to the percentage of bone defects (15%, 20%, 25%, 30%). Radiographs were taken weekly to evaluate the bone regeneration and union. The bone union time was measured between the osteotomy and the cortico-medullary differentiation by examining radiographs. The healing index was defined as the union time (week) per amount (cm) of bone defect. Eight rabbits, 2 from each groups with the bone defects, were investigated by histopathologic examination. RESULTS: The mean union time was approximately 7.0 to 7.3 weeks. The healing index in groups that had a large percentage of bone defects was less than in groups that had a small percentage of bone defects. The periosteum-resected group did not show bone regeneration. Histopathologic examinations showed intramembranous and atypical endochondral ossifications along the periosteum and typical endochondral ossification at the center of the bone defects. CONCLUSION: Spontaneous bone regeneration may be used in children to fill the bone defect instead of performing an internal bone transport. Spontaneous bone regeneration is useful in cases of mid-shaft bone defects or when the remaining bone fragments are large enough for an external fixation application.