Relapse tendency in maxillary arch width in unilateral cleft lip and palate patients with different maxillary arch forms

Objective: The aim of this study was to investigate the relapse tendency in the maxillary dental arch widths in unilateral cleft lip and palate patients with different types of maxillary arch form. Subjects: Thirty-two unilateral cleft lip and palate patients treated by one-stage surgical palatal closure were included. The subjects were divided into three groups according to the types of the maxillary arch forms: group A, symmetrical arch form; group 13, collapse of minor segment; group C, collapse of both segments. Methods: Using dental casts obtained at three different times, relapse in the intercanine, interpremolar, and intermolar widths in each group was assessed and differences between groups were investigated. Results: Patients in group A showed stable results in all measurements. Patients in group B showed posttreatment relapse in the intercanine width only, whereas patients in group C demonstrated significant posttreatment relapses in the interpremolar and intermolar widths. Comparison between groups showed more significant relapse in the interpremolar and intermolar widths of group C than in those of group B. Conclusion: The types of the maxillary arch forms in unilateral cleft lip and palate patients might play a stronger role in the stability of the maxillary dental arch widths after orthodontic treatment in patients with collapse of both segments and a severe degree of maxillary narrowness.