Effect of maxillary advancement on velopharyngeal function in cleft lip and palate: 20 years of experience.

This retrospective study aimed to investigate the impact of orthognathic surgery with maxillary advancement (MA) on the velopharyngeal function (VF) in individuals with cleft lip and palate (CLP). The study included 651 patients with repaired CLP, both sexes, aged over 18 years who underwent MA alone or in combination with nasal procedures and/or mandibular osteotomy, operated between 2000 and 2019. The main outcome measures were nasalance (nasal text-NT and oral text-OT) and velopharyngeal orifice area measurement (VA), determined by nasometry and pressure-flow technique, respectively. Preoperatively, mean nasalance scores for NT and OT indicated normality, and VA demonstrated borderline-inadequate velopharyngeal closure in all patients. Following MA, a significant increase in nasalance scores for NT and OT occurred (p < 0.001), revealing hypernasality in those undergoing MA combined with nasal procedure (MAN, N = 191), bimaxillary orthognathic surgery with nasal procedure (BON, N = 227) and bimaxillary orthognathic surgery (BO, N = 151). Conversely, nasalance scores remained within the normal range for those undergoing isolated maxillary advancement (IMA, N = 82). VA exhibited a significant increase leading to the classification of VF as inadequate in the BON and MAN groups. Overall, MA contributed to VF deterioration, resulting in the appearance of hypernasality and increased VA, particularly when combined with nasal procedures.