Biopsychosocial outcome of orthognathic surgery and aesthetic perception of Hong Kong Chinese

Abstract

Orthognathic surgery improves the functional, aesthetic and psycho-social aspects of patients. Jaw movements during this type of surgery will probably affect pharyngeal airway dimensions and certainly will affect facial aesthetic aspects and in this context patients’ social interaction. This thesis aims: (1) to summarize current evidence from systematic reviews that evaluated pharyngeal airway changes after mandibular setback with or without concomitant maxillary osteotomies; (2) to investigate short- and long-term three-dimensional changes of pharyngeal airway morphology in dento-skeletal class III patients after orthognathic surgery; (3) to collect evidence from published systematic reviews that have evaluated pharyngeal airway changes related to mandibular advancement with or without maxillary procedures; (4) to investigate short- and long-term post-surgical three-dimensional changes of pharyngeal airway morphology in dento-skeletal class II orthognathic patients; (5) to determine the reliability and validity of orthognathic-relevant translated FACE-Q scales among Hong Kong Chinese orthognathic patients; (6) to assess and compare the changes in satisfaction with facial appearance and psycho-social well-being in orthognathic patients; (7) to assess the relationships between facial attractiveness and neoclassical canons, golden proportion and the recommended ‘ideal’ ratios and angles in Hong Kong Chinese; (8) to assess the aesthetic perception on male and female facial profiles in three-dimensional photographs among orthognathic patients and laypersons . Study 1: An overview of systematic reviews studying changes in pharyngeal airway dimensions and respiratory parameters after mandibular setback was performed. Although mandibular setback osteotomies reduce pharyngeal airway dimensions, no evidence confirming post-surgical obstructive sleep apnea (OSA) exists. In severe dento-skeletal class III deformity cases, two-jaw surgeries should be considered. Study 2: Pre- and post-surgical three-dimensional pharyngeal airway changes were measured in dento-skeletal class III orthognathic patients. This surgery led to a statistically non-significant reduction of pharyngeal airway volume in both short- and long-term post-surgically. Study 3: A systemic literature search on systematic reviews evaluating changes in pharyngeal airway dimensions after mandibular advancement was performed. Maxillo-mandibular advancement is advocated to increase pharyngeal airway dimensions and was found to be beneficial to patients suffering from OSA. Single-jaw mandibular advancement increases pharyngeal airway dimensions, but evidence from the long-term result is lacking. Study 4: Pre- and post-surgical three-dimensional pharyngeal airway changes were measured in dento-skeletal class II orthognathic patients. Two-jaw surgery with segmentation improved oropharyngeal airway parameters significantly in the short-, but not long-term. Study 5: Orthognathic surgery-relevant FACE-Q scales were translated and validated into Hong Kong Chinese. All translated scales showed a high reliability and validity. Study 6: Orthognathic-relevant FACE-Q scales were administered pre- and post-surgically to orthognathic patients. Orthognathic surgery significantly improves patients’ satisfaction with their facial appearance, psychological well-being and social function. Study 7: The rated facial attractiveness based on 3-dimensional photographs was related to the recommended ideal’ parameters. Only a few parameters were found to significantly correlate with beauty perception of Hong Kong Chinese. Study 8: Aesthetic perception of different facial profiles was studied among orthognathic patients and laypersons. While dento-skeletal class I was generally considered as the most attractive profile for both genders, orthognathic patients preferred a bimaxillary protrusive female profile.