Accuracy of dental arch form in customized fixed labial orthodontic appliances

•Arch form accuracy is compared between extraction and nonextraction groups.•The arch form is designed by assessing the root position and shape of alveolar bone.•The arch form can be accurately achieved with and without premolar extraction.•The posterior arch discrepancy is higher than the anterior arch discrepancy.•Arch form accuracy between maxilla and mandible has a moderate correlation.