Background and objectives: New technologies allow maxillary 3-D repositioning, however, the maxillary widening stability is unpredictable, with severe intermolar contraction post-surgically. We believe the key in maxillary widening stability is maintaining the intermolar distance with a trans-palatal bar for six months after surgery, waiting for complete bone healing.

Methods: Twenty patients 15–52 years old (aver 29.5 y.o.) underwent maxillary widening divided in four groups of 5 individuals each. #1: symmetrical anterior and posterior maxillary widening, #2: anterior maxillary widening, #3: posterior maxillary widening, #4: symmetrical anterior and posterior widening with maxillary advancement or posterior repositioning; with or without vertical changes. Patients requiring maxillary A–P or vertical movements were treated with pre-shaped semi-rigid fixation with 1.5 mm thick plates and either 4 or 6 mm screws at the piriform rims. Dental models were used to digitalize and measure the intermolar distance before surgery, at braces removal and 6 months after.

Results: The intermolar distance was equal at braces removal and 6 months after, with 1 mm discrepancy, statistically insignificant.

Conclusions: The maxillary widening stability is warranty by utilizing a transpalatal bar 6 months after surgery. Key words : maxillary widening; semi-rigid fixation; Le Fort I; maxillary deficiency