Where is it common to modify the height of contour during mouth preparation?

The modification of the height of contour during mouth preparation is typically done on the lingual surfaces of mandibular teeth. This is because the lingual height of contour is crucial in determining the path of insertion and removal of the removable partial denture (RPD). By adjusting the contour in this area, dental professionals can ensure that the RPD seats properly and comfortably, while also aiding in retention and stability.

In the context of mandibular teeth, the lingual contour tends to be more significant due to the anatomy and positioning of the teeth, as well as the space available for the RPD. It helps to prevent any interference with the tongue, which can have a substantial effect on the patient's comfort and function. Additionally, modifying the height of contour in this region can enhance the overall aesthetics and functional performance of the denture.

Other surfaces mentioned, like the buccal of mandibular teeth, labial of maxillary teeth, and mesial of maxillary teeth, may not play as critical a role in the retention and proper seating of the RPD, thus making the lingual of mandibular teeth the primary focus during adjustments.