ObjectivesOral appliance (OA) has been increasingly used for the treatment of obstructive sleep apnoea hypopnea syndrome (OSAHS). OAs work by propelling the mandible, increasing the upper airway calibre and reducing collapsibility. While they have shown efficacy in reducing OSAHS, long‐term use can lead to adverse effects, such as dental displacement. The present study focuses on the impact on dental displacements of the NARVAL® computer‐aided design and manufacturing OA from the ResMed laboratory.Materials and MethodsThe study included 39 patients aged 18 or older who were treated for OSAHS using OAs initiated between 2019 and 2021 and had initial digital dental impressions. A new digital print was taken for each patient using the TRIOS 4 Wireless intra‐oral scanner from 3SHAPE. Dental displacement was measured using a 3D system's GEOMAGIC design X 3D reverse engineering software. The study analysed different blocks of teeth in both the maxillary and mandibular arches. Statistical analysis was conducted to determine the significance of dental displacements.ResultsPatients had been wearing the OA for an average of 2.5 years. The study found dental displacements in both the maxillary and mandibular arches. However, these displacements were not statistically significant. Qualitative analysis revealed palatoversion and vestibuloversion, while quantitative analysis showed minor dental displacements.ConclusionThis study on patients wearing the NARVAL® OA for an average of 2.5 years found dental displacements in both the maxillary and mandibular arches. However, these displacements were not statistically significant. The results suggest that the OA, designed using a complete digital workflow, did not significantly impact dental positions. To confirm the impact, further investigations with larger sample sizes, an exclusively digital protocol and a control group are required.