Objective To investigate the changes of epidermal growth factor（EGF） in saliva and saliva flow rate during orthodontic tooth movement. Methods Twelve adult orthodontic patients with maxillary protrusion and anterior increased overjet were selected. The cases were all treated by extracting the maxillary first premolar. A segmental arch technique was fixed between canines and the first molar in upper jaw. The canines were given 250 g initial force for distal movement. The saliva was collected in 0, 3, 7 and 30 d after orthodontic force application was exerted. The levels of EGF were measured by enzyme-linked immunosorbent assay（ELISA） and the salivary flow rate was measured. All the data were statistically analyzed using SPSS 16.0. Results The levels of EGF in saliva didn’t have statistically significant difference in 0, 3, 7 and 30 d during the orthodontic tooth movement（P＞ 0.05）. However, the saliva flow rate detected in 3, 7 and 30 d had significant difference compared to saliva flow detected in 0 d（P＜0.05）. Conclusion Mechanical stimulation of appliances caused the regulation of nervous reflex to increase saliva flow rate, but the appliances and orthodontic force couldn’t cause organism regulation to make salivary glands secrete more EGF.
