Impact of surgical orthodontic treatment on quality of life in Chinese young adults with class III malocclusion: a longitudinal study

BACKGROUND: The quality of life in Class III malocclusion patients are worse than those without the disorder and previous studies have shown that surgical orthodontic treatment has a different effect on these patients compared with mild or moderate malocclusion. This study aimed to investigate the changes in quality of life in patients with Class III malocclusion during surgical orthodontic treatment in Chinese young adults. METHODS: The 14-item Short Form Oral Health Impact Profile (OHIP-14), and the 22-item Orthognathic Quality of Life Questionnaire (OQLQ) were used to assess the effect of surgical orthodontic treatment on the quality of life in 21 patients with Class III malocclusion at pre-treatment (T(0)), pre-surgical orthodontic treatment (6 to 8 months, T(1)) and post-surgical orthodontic treatment (6 to 8 months after surgery, T(2)), and 24 healthy individuals were included as controls. The comparisons in numerical variables between patients and controls were performed using Mann-Whitney U test. The scores of the two questionnaires between T(0), T(1), T(2) and controls (Tc) were compared using generalized estimating equation. RESULTS: According to OHIP-14 questionnaire, the mean scores in T(0) and T(1) were higher than those in T(2) and Tc (P < 0.001), and a significant decrease was observed after post-surgical orthodontic treatment (P < 0.001), which achieved a level similar to the control group (P > 0.05). As to OQLQ questionnaire, the mean scores of all domains showed a significant increase between T(0) and T(1) except for awareness of dentofacial aesthetics (P > 0.05) and social aspects of dentofacial deformity (P > 0.05), followed by a significant decrease between T(1) and T(2). CONCLUSION: Surgical orthodontic treatment may improve quality of life in patients with Class III malocclusion, but pre-surgical orthodontic treatment may have an adverse effect on quality of life.