Analysis of soft tissue profile changes after mandibular advancement surgery

Area of Science:

• Orthodontics and Maxillofacial Surgery
• Cephalometric Analysis
• Skeletal and Soft Tissue Changes

Background:

• Mandibular advancement surgery is crucial for correcting Class II malocclusions.
• Understanding soft tissue response to skeletal changes is vital for predictable outcomes.
• Facial patterns, particularly divergence, may influence soft tissue behavior post-surgery.

Purpose of the Study:

• To analyze soft tissue profile alterations following mandibular advancement surgery.
• To evaluate the impact of skeletal relapse on soft tissue changes.
• To investigate the influence of different Class II facial patterns on these changes.

Main Methods:

• Cephalometric analysis of 30 patients undergoing sagittal split osteotomy.
• Radiographic assessment at pre-operation, 1 week, and 14 months post-operation.
• Classification of patients into low-, medium-, and high-angle groups based on mandibulonasal plane angle.

Main Results:

• Soft tissue pogonion and mentolabial fold generally followed skeletal movement (nearly 1:1 ratio).
• Skeletal relapse (1.3-1.5 mm) reduced soft tissue change correlation to approximately 60%.
• The low-angle group showed distinct soft-to-hard tissue ratios, though not statistically significant.

Conclusions:

• Soft tissue pogonion is a reliable reference for planning mandibular advancement.
• A 60% soft tissue to skeletal movement ratio at the chin offers a realistic prediction.
• Facial pattern variations may influence soft tissue response, warranting further investigation.