The partial denture must be designed so that

1) it will not stress abutment teeth beyond their physiologic tolerance, 2) it can be easily placed and removed by the patient, 3) it will be retained against reasonable dislodging forces, and 4) it will not create an unfavorable appearance. It is necessary that the diagnostic cast be surveyed with these principles in mind. Xlouth preparation should therefore be planned in accordance with certain factors that will influence the path of placement and removal.