Improperly installed or nonexistent brick ties in a wall
Obviously the ideal solution if the birckwork is generally poor is to rebuild the wall. 

In this case this doens't seem to be an option. To replace existing ties that have problems or sections of the wall where ties are missing you can get drill and fix wall ties. I believe you can get this type of system from Helifix in the UK but I'm sure similar systems exist around the world. You can get systems that rely on some fairly unattractive face plates but other systems do not rely on this but have a resin bond to the brickwork. You will probably need specialist advice on what the right system for you is and to identify if there are any other issues associated with the poorly constructed wall other than the lack of ties.