In surgically treated patients with clefts of the lip, alveolus, and/or palate, the vertical, transversal, and sagittal development of the maxilla is influenced by intrinsic, functional, and iatrogeneous (surgical) factors. To evaluate the effect of intrinsic and functional factors on dental arch development, we examined and compared unoperated adult individuals with different types of clefts. Dental casts of 37 Indonesian adults with unoperated unilateral clefts were studied: 15 subjects with unilateral cleft lip and alveolus (median age: 24 years) and 22 subjects with complete unilateral cleft of lip, alveolus, and palate (median age: 25 years). Dental arch dimensions were measured and evaluations of arch form were made. The Student's t-test showed that arch width and arch depth were significantly smaller in the complete-cleft group. There is a tendency for the smaller segment to be positioned more cranially in the complete-cleft group. Our conclusion was that subjects with an unoperated complete-cleft lip, alveolus, and palate develop an arch form that is significantly different from that in subjects with unoperated cleft lip and alveolus.