Evaluating retetion of the removable partial dentures supported by implants when changing the shape of the supporting alveolar

It is necessary when designing removable partial dentures to be fixed, stable and well supported for improving patient comfort, and decreasing damages on soft tissues and dental abutments, the alveolar ridge has a strong influence in planning for treatment and interpretations biomechanical when treated with removable partial dentures, and have four shapes in the sagittal plane which are horizontal shape, concave shape, distal ascending shape and descending shape.