The purpose of this study was to compare the alignment pattern of the constricted maxillary dental arch by fixed orthodontic treatment (FOT) in the well-aligned and constricted arches of unilateral cleft lip and palate (UCLP) patients. 19 UCLP patients were divided into Group 1 (well-aligned arch, n = 9) and Group 2 (constricted arch, n = 10). After the cephalometric and maxillary dental arch variables before (T1) and after FOT (T2) were measured, statistical analysis was performed. There were no significant differences in the surgical timing of cheiloplasty, palatoplasty, and secondary alveolar bone grafting and in the surgical method of cheiloplasty between the 2 groups. However, Group 2 had a higher percentage of palatoplasty method, which could leave the denuded bone for secondary healing than Group 1 (P < 0.05). Although Group 2 showed more constriction and asymmetry in the maxillary dental arch compared to Group 1 at the T1 stage (inter-second premolar width, greater segment angle [GSA], and lesser segment angle [LSA], all P < 0.05), these problems could be effectively resolved by FOT. As a result, at the stage T2, there was no significant difference in all the variables between the 2 groups. During T1-T2, there was a different pattern in change of variables between Groups 1 and 2 (anterior segment angle in the greater segment [P < 0.05] in Group 1 and U1-SN [P < 0.01], inter-molar width [P < 0.05], GSA [P < 0.05[, and LSA [P < 0.01] in Group 2). Therefore, according to the maxillary dental arch shape, different strategy is necessary to obtain proper alignment by FOT.