The effect of orthognathic surgery on facial expressions and psychosocial well-being - a 4D preliminary study

• Applicant: Dr. Anja Quast
• Subject Area: Dentistry, Oral Surgery
• Term: from 2019 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 427616114

Facial identity and facial expressions have a major impact on our daily communication and self-perception. Due to skeletal and dental harmonization by combined orthodontic and surgical treatment, facial soft tissue changes in morphology and function. However, the extent of the dynamic soft tissue changes and the effect on facial expressions is discussed controversially. To the best of our knowledge, no studies exist investigating whether pre- and postsurgical differences in facial movement affect psychosocial well-being. The aim of this prospective, single-arm, monocentric study is to determine the psychosocial well-being and facial expressions of patients who undergo orthognathic surgery one day before (T0) and four months after (T1) surgery. The sample consists of 20 patients with need for orthognathic surgery from the department of orthodontics at the University Medical Center Goettingen. The analyses of facial movements are performed by non-invasive, four-dimensional stereophotogrammetry by a motion capture system, which records 60 three-dimensional images per second. It is an innovative and objective method to assess facial expressions. Each patient performs two expressions: 1) maximal smile and 2) lip purse. The change in magnitude, speed and motion similarity between T0 and T1 is measured. Psychosocial well-being in the fields of quality of life, self-efficacy and body image is assessed using a set of validated questionnaires. Since for most patients improvement in quality of life is the primary motivating factor for orthognathic surgery, the oral health related quality of life is defined as primary outcome. Statistical analysis includes the pre- and postsurgical comparison of facial expressions and psychosocial well-being as well as the correlations between both factors. We hypothesize that orthognathic surgery improves psychosocial well-being and changes facial movements. A positive correlation between the magnitude of maximal smile and quality of life is expected. The results of this study contribute to patient-centered pre- and postsurgical care and help to optimize soft-tissue related orthognathic surgery planning.

• DFG Programme: Research Grants