Purpose: To investigate the relationship between root resorption related to fixed appliance and the variables including sex, age.
Methods: 44 patients were divided into four groups according to sex and age: juvenile males, juvenile females, adult males, adult females. The length of incisors was calculated according to orthopantomograph and study models of pre- and post-treatment, and the relationship between patients' sex and age and root absorption pre- and post-treatment was analyzed by paired t test.
Results: Root absorption occurred in every patient. There was no significant difference between the same-age groups of males and females (P<0.05); However, there was significant difference between adult groups (both males and females) and juvenile groups (P<0.01).
Conclusion: Root absorption occurs in every fixed-appliance case. Fixed-appliance-caused root absorption has no significant correlation with sex;however, absorption of adult groups is of higher level than that of juvenile groups.