The aims of this study were to investigate the initial time at which pain occurs after insertion of two initial wires of different sizes, the duration of the pain, the areas affected within the mouth, the level of self-medication, the effect of this pain on daily life, and whether gender is important in the perception of pain. The study group consisted of 109 patients (52 boys, 57 girls) with a mean chronological age of 13.6 years for boys and 14.7 years for girls. Insertion of either a 0.014 or 0.016 inch wire was by random selection. Following insertion of the archwires, a questionnaire comprising a total of 49 questions was given to the patients. They described the time of initial pain in the first question, answered the next 24 questions as 'yes' or 'no', and used a visual analogue scale for the final 24 questions. No significant differences were found in terms of gender, in the perception period of initial pain as regards the areas affected within the mouth or the effect of pain on daily living when the 0.014 and 0.016 inch wire groups were compared at 6 hours, 1, 2, 3, 4, 5, 6 and 7 days. At 24 hours, which was found to be statistically significant, more pain relief was used in the 0.014 inch archwire group. The results show that in both groups, initial pain was perceived at 2 hours, peaked at 24 hours and had decreased by day 3.