Objective: The aim of this research was to determine the transverse stability of the segmental Le Fort I osteotomy technique.

Patients and methods: 21 patients who underwent surgery between September of 2009 and November of 2010, follow-up average 9.0 months, DS ± 3.4; age average 20.4 years, DS ± 2.7. An advance Le Fort I Osteotomy surgery was performed. 13 patients with maxillary segmentation (9 into 2 segments, and 4 into 4 segments) versus 8 patients with no segmentation (control group). In each case, cast models were taken and the intercanine and intermolar distance was measured preoperatory ( T ₀ ), planned ( T ₁ ), and postoperative ( T ₂ ).

Results: Intercanine expansion was obtained in 6 procedures average 1.13 mm, DS ± 0.77; and intermolar expansion in 8 procedures average 2.19 mm, DS ± 0.90. Intercanine reduction was obtained in 7 procedures average 0.41 mm, DS ± 0.44; and intermolar reduction in 5 procedures average 1.20 mm, DS ± 1.12. In the cases of segmentation a good intercanine transversal stability was observed in 92% of the cases and 39% in intermolar. In the expansion, the stability was good at an intercanine level 100%, and 58% at an intermolar level. In the reduction, a good stability in intercanine level was observed in 85% of the cases, unlike the intermolar level, where the stability was low in 100% of the cases, with statistic significance, P = 0.028.

Conclusions: The segmental Le Fort I osteotomy showed to be more stable at an intercanine than an intermolar level. The expansion movement was more stable in both intercanine and intermolar level, than in the transversal reduction.

Conflict of interest: None declared.