Estimado Rubo,
my opinion about the possibility to open 2.5 space reach from upper occlusal view.
I think you can see there is upper midline deviation toward the left so 2.3 is in a distal position.Now we have to analyze upper molar position ( first class position of 2.6 and III class position of 1.6 ) to see if 2.6 mesialized. On OP If you measure the distance between 1.6 and skeletal maxillary midline and 2.6 and the same midline you will see that they have about the same distance from that midline.
So the mandible seems to shift toward the right. That's my honest opinion of the different molar classes.
But iven if There was 2.6 very important molar mesial shift ( and I don't think so) you can gain the space for 2.5 extracting 2.8 and move back 2.7 and 2.6.
Luca

PS Manuel has written " Clase III esqueletica principalmente de causa mandibular", so why do you want to "avance del maxilar mediante cirugia"?

PS Gertdalpozzo is a nickname, my name is Luca