Introduction: Rigid Fixation has given significant advantages to Orthognathic surgery mainly in terms of improved stability and comfort for the patient. Traditionally it has been said that each bone plate should be fixed at least with 2 screws at each end to achieve stable fixation.

Considering that the quantity of osteosynthesis material we place increases the cost of surgery and that sometimes it is difficult to find an appropriate bone cortical thickness for proper fixation with various screws in this study we evaluated the stability of the maxilla after performing Lefort I osteotomy advancement and fixation with 4 straight miniplates contoured and secured with 2 screws each for a total of 8 screws.

Materials and methods: 17 patients were evaluated taken standardized profile cephalometric X rays in 3 different times. Before surgery (T1), after surgery (T2) and long term (more than 1 year) follow up (T3), where cephalometric measurements were taken for analyzing stability both horizontally and vertically.

Standardization was performed intra- and inter-investigator for the cephalometric tracings and measurements finding intraclass correlation between 0.8 and 1. Analysis of the results was done by applying SPSS for Windows, descriptive statistics, T student test and Shapiro Wilks. Assuming p < 0.05.

Results and conclusions: There were no statistically significant differences when comparing T2 to T3 neither in the horizontal nor in the vertical plane in the various measurements used. This study shows this type of fixation is sufficient to obtain long-term stability.

Conflict of interest: None declared.