Abstract Objective: The purpose of this study was to examine the three-dimensional characteristics of the palatal configurations in incomplete unilateral cleft lip and palate (UCLP) patients and to determine whether there are differences in the effect of early orthopedic treatment between complete and incomplete UCLP patients. Design: Eight infants with incomplete UCLP and 12 infants with complete UCLP, selected at random, wore Hotz plates, and 8 other infants with complete UCLP did not. Palatal impressions were taken of these patients immediately after birth and at 1, 2, 3, 4 (just before cheiloplasty), 6, and 18 months of age (just before palatoplasty). Using our measuring system, the palatal casts were measured and compared three-dimensionally. Results and Conclusions: The palate of the incomplete UCLP patients measured immediately after birth, compared with complete UCLP, showed: (1) smaller posterior arch width; (2) sagittal arch length did not differ; (3) incisal point was located more mesially; (4)...