Micro-vascular functional changes in the periodontal ligament and the corresponding changes in the periodontal tissue by orthodontic force

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 16592061
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Orthodontic/Pediatric dentistry
• Research Institution: Fukuoka Dental College
• Principal Investigator: ISHIKAWA Hiroyuki Fukuoka Dental College, School of Dentistry, Professor, 歯学部, 教授 (20184492)
• Co-Investigator(Kenkyū-buntansha): NAGATO Toshikazu Fukuoka Dental College, School of Dentistry, Professor, 歯学部, 教授 (80084284) ; HISANAGA Yutaka Fukuoka Dental College, School of Dentistry, Lecturer, 歯学部, 講師 (70352292) ; TAMAOKI Sachio Fukuoka Dental College, School of Dentistry, Lecturer, 歯学部, 講師 (40369046) ; YAMAMOTO Katsuyuki Hokkaido University, School of Engineering, Professor, 大学院・工学研究科, 教授 (10088867)
• Project Period (FY): 2004 – 2006
• Keywords: Periodontal ligament / Vascular network / Orthodontic force / Capillaroscope / Blood flow velocity / 3D reconstruction / Ion-etching / Root resorption

Research Abstract

The purpose of this study was to investigate functional and micro-structural changes in vasculature in the periodontal ligament and the following changes in the periodontal tissue due to orthodontic forces. This study established the methods to measure blood vessel diameter and blood flow velocity by using video capillaroscope for real-time monitoring of changes in the periodontal vasculature and the methods to investigate the relationships between the changes in the periodontal ligament vascular network and the periodontal tissue response by 3D reconstruction of microscopic tissue images and the ion-etching SEM method.
The monitoring of the periodontal vasculature was performed in the rat gingiva of the right maxillary first molar for 1 minute by using LED. The blood flow velocity and blood vessel diameter were measured on the video images. The vascular network and the red cell flow were clearly detected. The mean bleed vessel diameter was 34.44 ± 4.47 μ m and the mean blood velocity was 337.70 ± 31.24 μm/s.
The relationship between the periodontal vascular distribution and physiological root resorption was investigated by the 3D reconstruction of the tissue images and the ion-etching SEM method. The experiment was performed in rat tissue around the mandibular first and second molars. The blood vessels were mainly distributed between the central area of the periodontal ligament and the alveolar bone. In the root resorption areas, the blood vessels running along the resorption area were found. This suggested that the root resorption is influenced by the vascular distribution of the periodontal ligament.