This study investigated the relation between personality characteristics and types of jaw deformities and evaluated the influence of orthognathic surgery on personality characteristics.
The subjects consisted of 52 patients (16 males and 36 females) in whom jaw deformities were surgically corrected and the mean age at surgery was 26.3 years. They were divided into four groups based on the types of jaw deformities such as mandibular protrusion with or without maxillary retrusion, mandibular retrusion with or without maxillary protrusion, open bite and asymmetry.Personality characteristics were analyzed using Minnesota Multiple Personality Inventory (MMPI) and Rosenberg's Self-Esteem Scale before and six months after surgery, and the Kruskal Wallis test and t-test were used for statistical analyses.
Preoperative MMPI scores were not significantly different from normal values of their generation as a whole, but the distribution of Depression Scale and Self-Esteem Scale scores among the four groups were significantly different. The Depression Scale score in the asymmetry group was higher than those in the other groups and the Self-Esteem Scale score in the asymmetry group was lower than those in the other groups. After surgery, the Depression Score decreased in the asymmetry group and the Self-Esteem Scale score increased in all groups except the open bite group.
In conclusion, it is considered that patients with asymmetry are likely to have an inferiority complex and orthognathic surgery for such patients has a favorable effect on personality characteristics because the deformity and the change of full-face appearance are easily recognized by themselves.
