Comparison of aesthetic outcomes of maxilla-only, mandible-only, and bimaxillary orthognathic surgeries: A retrospective analysis

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.