Is Atypical Swallowing Associated With Relapse in Orthognathic Patients? A Retrospective Study of 256 Patients.

PURPOSE: To determine the association of atypical swallowing (AS) with relapse in patients undergoing combined orthodontic and orthognathic treatment. MATERIALS AND METHODS: In this retrospective cohort study, the clinical data of all patients who underwent combined surgical and orthodontic treatment from 1998 through 2015 at the University Hospital of Geneva (Geneva, Switzerland) were reviewed. The primary outcome variables were 1) AS and 2) post-treatment relapse. Other variables included, age, gender, dentofacial deformity (facial asymmetry, mandibular deficiency, mandibular excess, maxillary retrusion, open bite), surgical procedure performed (bilateral sagittal split osteotomy [BSSO] with or without Le Fort I osteotomy), and dental interocclusal relations according to Angle. RESULTS: Of the 256 patients investigated, 23 (9%) showed relapse at 1 year after treatment. Multivariate analysis showed that AS status (before treatment, odds ratio [OR] = 9.44, P = .005; after treatment, OR = 56.17, P < .001; before and after treatment, OR = 20.49, P < .001) was significantly associated with relapse. The presence of a pretreatment open bite also was associated with an increased risk of relapse (OR = 0.04, P < .001) regardless of AS status. CONCLUSION: The present study showed that in orthognathic patients 1) AS was associated with relapse regardless of dentofacial deformity or surgical procedure performed and 2) AS can appear after treatment in patients who were initially free of it.