Accuracy of maxillary positioning in bimaxillary surgery

Area of Science:

• Oral and Maxillofacial Surgery
• Orthognathic Surgery
• Surgical Accuracy

Background:

• Bimaxillary osteotomies are complex procedures requiring precise skeletal repositioning.
• Accurate vertical control of the maxilla is crucial for achieving desired aesthetic and functional outcomes.
• Existing methods for maxillary positioning may have limitations in precision.

Purpose of the Study:

• To evaluate the accuracy of a modified pin system for vertical control of maxillary repositioning.
• To assess the reliability of this system in bimaxillary osteotomies.
• To compare planned versus observed vertical and horizontal movements of the anterior maxilla.

Main Methods:

• Retrospective analysis of 239 patients undergoing bimaxillary osteotomies.
• Superimposition of preoperative and postoperative cephalograms.
• Statistical analysis of vertical and horizontal incisor movements using confidence intervals.

Main Results:

• Mean vertical deviation was -0.07 mm (95% CI -0.17 to 0.04 mm), not significantly different from zero.
• Mean horizontal deviation was 0.12 mm (95% CI -0.06 to 0.30 mm), also not significantly different from zero.
• No significant difference was found in variances between maxillary intrusion and extrusion (p=0.51).

Conclusions:

• The modified pin system, combined with interocclusal splints, provides accurate vertical control for the anterior maxilla.
• This technique demonstrates high precision in orthognathic surgery.
• The findings support the use of this modified pin system for reliable maxillary repositioning.