Abstract
BACKGROUND/PURPOSE: Orthognathic surgery addresses craniofacial and occlusal deformities caused by skeletal discrepancies. This study compares the aesthetic outcomes of maxilla-only, mandible-only, and bimaxillary surgeries, focusing on facial angles, proportions, and soft tissue aesthetics. It also identifies parameters most influencing postoperative aesthetics. MATERIALS AND METHODS: Sixty Taiwanese patients (30 males, 30 females) were divided into three groups: maxilla-only, mandible-only, and bimaxillary surgeries (20 patients per group). Pre- and postoperative cephalograms were analyzed using six cephalometric methods. Paired and independent t-tests (P < 0.05) were conducted to evaluate changes and deviations from reference norms. RESULTS: The results of the study showed that maxilla-only surgery could lead to significant improvements in midface aesthetics, especially a notable increase in the nasolabial angle (P < 0.05) and a reduction in UL-E line distances (P < 0.05). The mandible-only surgery could enhance the lower facial symmetry with significant changes observed in the H angle (P < 0.05), SN-MP angle (P < 0.05), and LL-E line distances (P < 0.05). Bimaxillary surgery resulted in the most comprehensive improvements, including a significant increase in the lower anterior facial height (LAFH, P < 0.05), an enhanced nasolabial angle (P < 0.05), and an overall improvement in facial balance. However, a decrease in postoperative nasal prominence was observed across all surgical types when compared to reference norms, suggesting that secondary adjustments may be required. CONCLUSION: Maxilla-only surgery improves midface proportions, while mandible-only surgery enhances lower facial balance. Bimaxillary surgery provides the most comprehensive outcomes. Individualized surgical planning and potential nasal refinements are crucial for optimal results.