S Chu1, H Ishikawa, T Kim, S Yoshida. 1. Department of Orthodontics, School of Dentistry, Hokkaido University, Sapporo, Japan. soowon@den.hokudai.ac.jp
Abstract
OBJECTIVE: The aim of this study was to evaluate the effectiveness of laser Doppler flowmetry (LDF) to discriminate postoperative scar tissue distribution on the palate. METHODS: Nineteen male Wistar rats at the 20th postnatal day were divided into experimental and control groups. In the experimental group, lateral palatal mucoperiosteum was excised to form scar tissue on the palate. At the 11th postnatal week, changes in the palatal blood flow were recorded with LDF in both groups by occluding exposed common carotid arteries. Perfusion values of nonoccluded (stable) and occluded states and the ratio of occluded to stable states were compared for scar tissue and normal tissue areas, and also for the normal tissue areas. After the LDF measurements, India ink-injected specimens and tissue sections were prepared for histological observations. RESULTS AND CONCLUSIONS: Scar tissue areas showed lower perfusion values both in the stable and occluded states, reflecting a lower vascular density in the scar tissue. The ratio of the occluded to stable states was higher in the scar tissue than in the normal tissue areas. In normal tissue areas, perfusion values of both the stable and occluded states appeared to vary, but the ratio did not vary among the areas. In the LDF study, the ratio of the occluded to stable states was considered to be the better parameter for discriminating scar tissue from normal tissue.
OBJECTIVE: The aim of this study was to evaluate the effectiveness of laser Doppler flowmetry (LDF) to discriminate postoperative scar tissue distribution on the palate. METHODS: Nineteen male Wistar rats at the 20th postnatal day were divided into experimental and control groups. In the experimental group, lateral palatal mucoperiosteum was excised to form scar tissue on the palate. At the 11th postnatal week, changes in the palatal blood flow were recorded with LDF in both groups by occluding exposed common carotid arteries. Perfusion values of nonoccluded (stable) and occluded states and the ratio of occluded to stable states were compared for scar tissue and normal tissue areas, and also for the normal tissue areas. After the LDF measurements, India ink-injected specimens and tissue sections were prepared for histological observations. RESULTS AND CONCLUSIONS: Scar tissue areas showed lower perfusion values both in the stable and occluded states, reflecting a lower vascular density in the scar tissue. The ratio of the occluded to stable states was higher in the scar tissue than in the normal tissue areas. In normal tissue areas, perfusion values of both the stable and occluded states appeared to vary, but the ratio did not vary among the areas. In the LDF study, the ratio of the occluded to stable states was considered to be the better parameter for discriminating scar tissue from normal tissue.