BACKGROUND: Orthognathic surgery significantly influences psychosocial well-being. Individuals with dentofacial deformities may experience psychological distress, characterized by negative affectivity (NA) and social inhibition (SI). When these 2 traits coexist, they define Type D personality. PURPOSE: The aim of this study was to estimate the prevalence of Type D personality traits in patients with Class III dentofacial deformities and assess changes in these traits, which inherently reflect variations in Type D personality, following orthognathic surgery. STUDY DESIGN, SETTING, SAMPLE: This prospective cohort study was conducted at Başkent University Department of Oral and Maxillofacial Surgery between November 2022 and March 2024. Sociodemographic data and psychological assessments were collected using the Type D Scale-14 preoperatively and 3 months postoperatively. PREDICTOR: The predictor variable was the preoperative personality trait, measured using the validated Type D Scale-14 questionnaire. This questionnaire comprises the following 2 subscales: NA and SI, each consisting of 7 items. Responses are scored from 0 to 4, resulting in scores ranging from 0 to 28. A score of ≥10 on both NA and SI subscales indicates a Type D personality. OUTCOME VARIABLE: The primary outcome variable was the postoperative personality trait, specifically changes in NA and SI, measured using the Type D Scale-14. The secondary outcomes were the prevalence of Type D personality traits before and after surgery. COVARIATES: The covariates were age, sex, marital status, and employment status. ANALYSES: Descriptive statistics and paired t-tests were performed to assess the differences between preoperative and postoperative results. A P value of <
.05 was considered statistically significant. RESULTS: The study sample comprised 41 participants (mean age: 22.24 ± 4.72 years), 65.9% (n = 27) of whom were female. The prevalence of Type D personality traits significantly decreased from 42.9% (n = 18) preoperatively to 17.1% (n = 7) postoperatively (P <
.05). When the subscales of NA and SI were examined, both scores showed statistically significant reductions (P <
.05). CONCLUSIONS: Significant differences were observed in NA and SI before and after orthognathic surgery. This study represents the first application of the Type D Scale-14 in the context of orthognathic surgery. Observed psychological improvement highlights the importance of preoperatively assessing patients' psychosocial conditions.