appropriate treatment for skeletal open bite is to intrude the molars (though difficult)

http://www.aensiweb.com/old/jasr/jasr/2012/497-505.pdf

Some  of  the  proposed  methods  in  growing  patients  are  high-pull  headgear  for  the  maxilla  or  cervical-pull 
headgear for the mandible, posterior bite blocks, the vertical chin cap and occlusal splints as well as the active
vertical corrector appliance (AVC) which uses repelling magnets embedded in acrylic to produce an additional
posterior occlusal force and posterior bite planes. Also functional appliances which are specifically designed and
fabricated with posterior bite blocks to accomplish posterior segment intrusion may be used. Unfortunately most
of  these  systems  are  limited  by  many  factors  including  patients'  compliance,  relative  number  of  dental 
anchorage  units  available,  allergy  as  well  as  unfavorable  reactionary  tooth  movement.  A  passive  system 
achieves  relative  intrusion  of  the  posterior  teeth  either  by  interfering  with  or  reducing  the  potential  of  molar 
eruption during growth.
While an active system, on the other hand, attempts to physically intrude the molars into
their  bony  support  (Owen  AH.,  1985;  Pfeiffer  JP  and  Grobety  D.,  1972;  Pfeiffer  JP  and  Grobety  D.  1982;   
Teuscher U., 1978; Iscan HN
et al.,
 2002; Woods MG and Nanda RS, 1988; Kiliaridis S
et al.,
 1990).
Compromised  esthetics  and  a  less  stable  outcome  than  for  intrusion  of  posterior  teeth  have  been  also 
considered drawbacks of incisor extrusion in these patients. So the most appropriate treatment for skeletal open
bite is to intrude the molars though molar intrusion is difficult.