Relapse after Le Fort I surgery in oral cleft patients: a 2-year follow-up using digitized and 3D models

This retrospective observational study aimed to evaluate and identify the relapse rate after orthognathic surgery for maxillary advancement (Le Fort I maxillary osteotomy) in oral cleft patients through digitized cephalograms and 3D dental models, following 2 years. Lateral cephalograms and dental casts of 17 individuals, enrolled in Orthodontics Department in Hospital of Rehabilitation of Craniofacial Anomalies, were carried out. The digital cephalometric tracings were evaluated in: T1-before surgery, T2-immediate after surgery, T3-6-month to 1-year after surgery. The dental study casts were digitized and evaluated in: F1-before surgery; F2-3-month to 1-year after surgery; F3-1 to 2 years after surgery. The analyses of the dental arches were performed directly on the scanned images. A single examiner previously trained and calibrated performed all the assessments. Repeated measures ANOVA was applied to study the variables and compare the periods, followed by Tukey test to evaluate the statistically significant differences, with level of significance of 5%. The digital cephalogram results showed that the vertical movement statistically differed from T2 to T3 (p = 0.002). The right and left premolar relationship in digitized models revealed that at F2 the individuals exhibited ¼ Class II and Class I, in 29.4 and 23.5% of the cases, respectively; and at F3, Class I, 58.8 and 70.6% of the cases, respectively. The cephalometry showed the relapse in the vertical movement after orthognathic surgery for maxillary advancement, but no relapse in the other evaluated parameters.