Effects of Rapid Palate Expander on Facial Soft Tissues and Dental Arch: Study Conducted with Stereophotogrammetry and Intraoral Scans in Cleft Patients

Introduction: This pilot study explores the impact of rapid palatal expansion on facial soft tissues and dental arches, utilizing stereophotogrammetry and intraoral scanner in a cleft population. Materials and methods: Forty-five patients with unilateral cleft lip-palate (27), bilateral cleft lip-palate (9), and cleft palate (9) were included and underwent rapid palatal expansion. Stereophotogrammetric scans were conducted using (VECTRA M3) and intraoral scans (CEREC Primescan) at T0 (expander application) and at T1 (end of activations). Superimpositions and variations in surface and volume within the right cheek, left cheek, upper lip, and lower third were executed using the VECTRA Analysis Module (VAM) to compare soft tissues at T0 and T1. Expansion of the dental arches was verified on Meshmixer. Results: In unilateral cleft lip and palate patients the increase in the cheek area was 0.88 mm2 and 2.06 cm3 on the cleft side, whereas on the cleft side was 0.92 mm2 and 2.18 cm3. In bilateral cleft lip and palate the increase was of 0.75 mm2 and 1.7 cm3 on the left side and 0.58 mm2 and 1.4 cm3 on the right and in cleft patients there is an increase of 0.79 mm2 and 2.05 cm3 on the left and 0.95 mm2 and 2.01 cm3 on the right. On upper lip area the increase was 1.19 mm2 and 1.7 cm3 in unilateral cleft lip and palate, 0.88 mm2 and 1.1 cm3 in bilateral cleft lip and palate and 0.85 mm2 and 1.2 cm3 in cleft patients. On lower third area the increase was 1.58 mm2 and 6.15 cm3 in unilateral cleft lip and palate, 1.62 mm2 and 5.34 cm3 in bilateral cleft lip and palate, 1.37 mm2 and 5.37 cm3 in cleft palate. On dental arches symmetric expansion was present in no patient with unilateral cleft lip and palate, 55.6% of bilateral cleft lip and palate patient and 88.9% of cleft palate. Discussion and conclusions: Palatal expansion influences soft tissues as well as dental arches in terms of surface and volumetric changes. It was not possible to identify a relationship between the expansion of the dental arches and effects on the soft tissues. In unilateral cleft lip and palate, there was a non-symmetrical expansion of the arch; however, the position of the cleft does not influence the expansion. A symmetric expansion was frequent in the isolated cleft palate. Volumetric changes are mostly evident in the lower facial third.