Preference is given to anterior abutments for overdentures because they provide better support and stability due to their strategic position and root morphology. Anterior teeth, particularly canines and incisors, often have longer roots and better bone support, which enhances anchorage and resistance to lateral forces. Additionally, preserving anterior abutments helps maintain alveolar bone volume and facial esthetics. Posterior abutments are less favorable as they are prone to greater occlusal load and may not provide sufficient retention for the prosthesis.

Reference: Essentials of Complete Denture Prosthodontics, S. L. Purkait, 2nd Edition.