WordNet (r) 3.0 (2006):

cleft palate
    n 1: a congenital fissure of the hard palate

Moby Thesaurus II by Grady Ward, 1.0:

30 Moby Thesaurus words for "cleft palate":
   bowlegs, camelback, clubfoot, crookback, defacement, deformation,
   deformity, disfigurement, flatfoot, freakishness, harelip,
   humpback, hunchback, knock-knee, kyphosis, lordosis,
   malconformation, malformation, misproportion, misshape,
   monstrosity, mutilation, splayfoot, swayback, talipes, teratology,
   torticollis, truncation, valgus, wryneck