El proposito fue evaluar los cambios de las medidas cefalometricas y del hueso hioides luego de cirugia ortognatica, correlacionando la posicion final de las estructuras. Se evaluaron prospectivamente las radiografias cefalicas laterales de 20 pacientes (11 mujeres y 9 hombres) clase III, a los cuales se les realizo cirugia ortognatica bimaxilar. En 10 pacientes se utilizo fijacion rigida (grupo 1) y en 10 fijacion intermaxilar (grupo 2). Se evaluaron en 4 tiempos: prequirurgico T0, Postoperatorio inmediato T1, 6 meses postoperatorio T2, 1 ano postoperatorio T3. El avance promedio del maxilar en el grupo 1 fue de 4.5±1.2 mm (P Abstract The purpose of this study was to evaluate changes in cephalometric measures and the hyoid bone after orthognatic surgery, correlating the final position of the structures. Lateral cephalic x-rays of 20 class III patients (11 females and 9 males) were evaluated in a prospective way, on which bi maxillary orthognatic surgery was performed. 10 patients had rigid fixation (group 1) and 10 had intermaxillar fixation (group 2). They were evaluated 4 times: presurgical T0, Immediate Postoperatory T1, 6 months postoperative T2, 1 year postoperative T3. The advance average of maxillar in group 1 was of 4.5±1.2 mm (P<0.05); in group 2 it was of 0.5±0.8 mm which was not statistically significant when comparing T0 and T1. The mandible decreased in group 1: 4.1±1.5 mm (p <0.05) and in group 2: 3.8±0.9 mm (p<0.05). When comparing cephalometric measures of T1 with T2 and T3, there were no statistically significant differences in both maxillaries. With regards to the hyoid bone, was that in group 2, there was a more inferior position in T1, (P<0.05); in T2 and T3 the hyoid returned to its more superior position (P<0.05). This study suggests that changes in the position of hyoid after orthognatic surgery do not correlate with the post surgical changes of maxillaries.