OBJECTIVETo investigate the dental arch discrepancy in UCLP patients and the characteristics of orthodontic treatment of this kind of patients.

METHODS48 Unilateral cleft lip and palate patients were examined clinically and dental arch transverse discrepancy were recorded. Treatment plan was made according to the maloccusion of each patient.

RESULTS(1). Dental arch transverse discrepancy was seen in 60.4%, bilateral posterior crossbite in 33.3%, and unilateral posterior crossbite in 16.7% of patients with UCLP, respectively. (2). Serious crossbite was often seen in bicuspid region, so expansion in this area is the main task of orthodontic treatment. (3). Dental arch transverse discrepancy was usually mild in molar region. The upper molars were moved palatally in 10.4% of patients with UCLP.

CONCLUSIONSUpper arch expansion is often needed in patients with UCLP, and the potential of dental arch expansion was large. The decision of upper tooth extraction in patients with moderate crowding should be made after dental arch expansion. Dental arch expansion should be done before alveolar bone grafting. Prolonged usage of the retainer is often needed.