When should modifications be made to high survey lines on abutment teeth?

Modifications to high survey lines on abutment teeth are necessary when the shoulder of the clasp assembly needs to be positioned above the survey line. This is critical because the survey line indicates the contour of the teeth in relation to the ideal placement of the denture components, particularly the clasps. The shoulder of the clasp is designed to provide stability and retention for the removable partial denture, and its proper positioning relative to the survey line ensures that it can engage adequately with the tooth structure without causing impingement on the soft tissues or compromising the dental arch.

In cases where the shoulder is below the survey line, it may prevent effective clasp engagement and result in poor retention of the prosthesis. Adjusting the survey line to position the shoulder appropriately contributes to the overall function and comfort of the denture. Thus, making modifications at this stage is vital for the successful integration of the removable partial denture with the patient's oral anatomy.