This within subject clinical experiment assessed oral health impacts before and after Invisalign orthodontic treatment and their relationships with personality characteristics. 50 patients (26 females and 24 males; mean age = 27.62 ± 8.25 years, SE = 1.17, 95% CI = 24.71-29.89 years) were assessed before and after treatment with Invisalign orthodontic treatment. Treatment clinical success was evaluated according defined clinical guidelines. Oral health impacts before and after Invisalign orthodontic treatment were measured via the Oral Health Impact Profile (OHIP). Personality features were measured via the NEO Five-Factor Inventory (NEO-FFI). Probability of α = .05 was utilized to identify significant findings. Females scored less OHIP scores after treatment (had less negative impacts) in comparison to baseline OHIP scores (t = 3.782, df = 25, P = .001, 95% CI of mean difference = 2.750-9.327). Among males, openness scores (R2 = .911, B = 5.235, 95% CI for B = 0.062-10.407, t = 2.601, P = .048) were able to predict OHIP scores before treatment; meanwhile, extraversion (R2 = .959, B = - 8.224, 95% CI for B = - 14.605-1.843, t = - 3.313, P = .021), openness (R2 = .959, B = 21.795, 95% CI for B = 10.737-32.853, t = 5.067, P = .004), and conscientiousness (R2 = .959, B = 10.293, 95% CI for B = 4.796-15.790, t = 4.813, P = .005) scores were useful to predict OHIP scores after treatment (R2 = .959, P < .05). NEO-FFI scores were not useful to predict OHIP scores before or after treatment among females (P > .05). These findings demonstrate that oral health impacts of Invisalign orthodontic treatment and personality profiles contribution to oral health impacts were different between genders.