Soft tissue profile changes after bilateral sagittal split osteotomy for mandibular setback: a systematic review.

Area of Science:

• Oral and Maxillofacial Surgery
• Orthognathic Surgery
• Facial Plastic Surgery

Background:

• Bilateral sagittal split setback osteotomy (BSSO) is a common procedure in orthognathic surgery.
• Understanding soft tissue changes following BSSO is crucial for predicting aesthetic outcomes.
• Both rigid internal fixation and wire fixation have been used for BSSO, with varying implications for soft tissue stability.

Purpose of the Study:

• To evaluate the soft tissue to hard tissue ratio changes after bilateral sagittal split setback osteotomy (BSSO).
• To compare these ratios between rigid internal fixation and wire fixation techniques.
• To assess short-term versus long-term soft tissue alterations.

Main Methods:

• A systematic literature search was conducted across multiple databases (PubMed, Medline, CINAHL, Web of Science, Cochrane Library, Google Scholar Beta).
• Eight articles were included in the review (2 prospective, 6 retrospective).
• Follow-up periods ranged from 1 to 12.7 years for rigid fixation; two wire fixation studies were included.

Main Results:

• Short- and long-term ratios of the lower lip to lower incisors showed minimal differences, trending towards 1:1 long-term.
• Mentolabial fold ratios to point B remained consistently 1:1.
• Soft tissue pogonion to pogonion ratio was 1:1 short-term, with a trend towards reduction long-term; upper lip protrusion was variable.

Conclusions:

• Drawing evidence-based conclusions on soft tissue changes post-BSSO is challenging due to study limitations.
• Retrospective designs, suboptimal study quality, and lack of standardized measurements hinder reliable data.
• High-quality prospective studies excluding adjunctive procedures like genioplasty or maxillary surgery are necessary.