Objective The aim of this study was to analyse the stress distribution in the periodontium of the maxillary first molar used as the anchorage forces to provide biomechanical basis for the clinical practice. Methods By CT scanning and ANSYS10.0 finite element analysis software, a three- dimensional finite element model of the maxillary first molar and the periodontal tissue was established. Then, three different magnitudes of anchorage forces were applied to the molar to analyse the stress distribution in the periodontium of the maxillary first molar. Results Under anchorage forces, compressive stress distributed mostly at the mesio- buccal neck and mesio neck of the mesio- buccal root and the mesio neck of the palatal root, tensile stress distributed mostly at distobuccal neck of the disto- buccal root. The maximum stress in the periodontium was situated at the mesio neck of the mesio- buccal root. The periodontium had the tendency of mesio- palatal rotation. With the anchorage force increased, the stress in the periodontium increased. Conclusion It should be consider if the buccal of maxillary first molar can provide enough anchorage during clinical practice.
