Does Transpalatal Distraction Affect Pharyngeal Airway Dimensions and Related Soft Tissues?

PurposePrevious studies of transpalatal distraction (TPD) have been based on dentoskeletal alterations of the jaws and nasal airway changes. The main aim of this study was to determine the effects of TPD on soft palate and pharyngeal airway dimensions and tongue posture.Material and MethodsThis was a retrospective cohort study. The sample was comprised of 16 patients with skeletal maxillary deficiency who had bilateral crossbite combined with a high palatal vault and partial or near total nasal obstruction treated with TPD using bone-borne distractors (Transpalatal Distractor, SurgiTec NV, Bruges, Belgium). This research was carried out on lateral cephalometric radiographs taken before distraction and after a distraction period of 6.75 ± 1.61 months. The primary predictor variable was pharyngeal airway dimensions and tongue posture. Other variables were demographic and lateral cephalometric parameters. Changes in the length, angle, and thickness of the soft palate; nasopharyngeal, retropalatal, retroglossal, and lower pharyngeal airway dimensions; and tongue length and height were evaluated. Data were analyzed by paired t test.ResultsThe sample included 16 adult patients (mean age, 25.13 ± 6.13 yr; 7 women, 9 men). The desired amount of distraction was achieved in all patients within 7 to 10 days. The total activation average was 8.38 ± 0.96. TPD caused statistically significant changes in sagittal nasopharyngeal airway dimensions (1.19 mm), the minimal oropharyngeal distance behind the tongue base (1.81 mm), and tongue height (2.12 mm).ConclusionsThe results of this study suggest that, in adult patients with nasal obstruction, TPD has the potential to increase sagittal nasopharyngeal airway dimensions and the minimal oropharyngeal distance behind the tongue, with an elevation in tongue posture. Further studies using cone-beam computed tomography that focus on how the bone-borne expander alters pharyngeal airway volume will make valuable contributions to the literature.