To study the influence factors of dental anxiety in patients with mini-implant anchorage (MIA) and the effect of preoperative anxiety level on postoperative pain.

The dental anxiety and postoperative pain of patients with MIA implantation in Foshan Stomatology Hospital were investigated by modified dental anxiety scale (MDAS) and visual analogue scale (VAS) . A total of 553 questionnaires were sent out and 509 effective questionnaires were recovered. The effective percentage was 92.04%. Group t-test was used to compare the MDAS among different genders, ages, education levels, marital status and income levels. Two-Way repeated measures ANOVA was used to evaluate the VAS score of postoperative pain in different anxiety levels.

The mean preoperative MDAS of patients with MIA implantation was 11.24 ± 3.05, 58.9% of which was higher than 11. The MDAS of male patients was 9.85 ± 2.12 while that of female patients was 12.41 ± 2.56 (t=-12.18, P<0.001) . The MDAS of 12-18-year-old patients was 13.27 ± 3.12, and that of over 18-year-old ones was 10.53 ± 2.36 (t = 10.51, P<0.001) . The MDAS of unmarried and married patients were 11.06 ± 2.96 and 11.63 ± 2.75, respectively (t = -2.07, P = 0.039) . The MDAS of the patients with education level of junior college or below was 11.95 ± 2.37 and that of undergraduate or above was 10.46 ± 3.01 (t = 6.23, P<0.001) . The MDAS value of patients with income lower than 20 000/month was 11.13 ± 2.14, and that of income of 20 000/month and above was 11.58 ± 3.02 (t = -1.82, P = 0.068) . There was statistical difference in the level of dental anxiety among the groups of gender, age, education level and marital status, but no statistical difference was found in the level of dental anxiety among the income groups. The VAS value of 2 hours after implantation in low anxiety group and high anxiety group were 2.12 ± 0.78 and 3.13 ± 1.28 (t = -11.23, P<0.001) ; and 6 hours after implantation in two groups were 5.83 ± 1.25 and 6.54 ± 2.12 (t = -4.37, P<0.001) ; and 24 hours after implantation in two groups were 1.93 ± 0.65 and 2.09 ± 1.13 (t = -2.04, P<0.001) ; and 48 hours after implantation in two groups were 0.35 ± 0.12 and 0.54 ± 0.21 (t = -14.78, P<0.001) . There was statistical difference in the VAS value of different anxiety levels at different time points.

The prevalence of dental anxiety in patients with mini-implant anchorage is high, which is closely related to gender, age, education and marital status. The patients with high anxiety before operation have high intensity of pain after operation.