Skeletal stability after inferior maxillary repositioning without interpositional graft

Area of Science:

• Orthognathic surgery
• Craniofacial reconstruction
• Maxillofacial surgery

Background:

• True vertical maxillary deficiency is a key feature of short face syndrome.
• Inferior repositioning of the maxilla (IRM) is a treatment option for improving facial aesthetics and function.
• IRM has been historically considered an unstable procedure.

Purpose of the Study:

• To evaluate the long-term post-surgical stability of inferior repositioning of the maxilla (IRM).
• To assess the stability of IRM fixed with L-shaped miniplates without bone grafting.

Main Methods:

• A cephalometric study analyzed linear measurements in eight young adult patients.
• Measurements were taken immediately preoperatively, immediately postoperatively, and at least 6 months postoperatively.
• Specific landmarks included the anterior nasal spine (ANS), A point, and others on an X-Y coordinate system.

Main Results:

• Average surgical movements were 4.65 mm at the I point, 5.32 mm at the ANS, and 4.70 mm at the A point.
• Relapse rates were 35% (1.60 mm) at the I point, 43% (2.23 mm) at the ANS, and 46% (2.10 mm) at the A point.
• Significant relapse was observed across all measured points.

Conclusions:

• Inferior repositioning of the maxilla (IRM) using L-shaped miniplates without grafting demonstrates long-term instability.
• The findings suggest that this method of internal rigid fixation is not reliably stable for correcting vertical maxillary deficiency.