The clasps and related abutments are the VM stress concen-tration positi on sontheclasp-retained prosthesis. It can decrease
the stress values on clasps obviously by putting a zygoma implant
on the affected side.Prostheses retained with clasps and two
zygoma implants can share the occlusal force even rationally and
prevent the abutments from rotational forces.Therefore, zygoma-
implant-retained prostheses are fit for the restoration of unilat-
eral maxilla defects.