Which structures are included in a maxillary impression?

The correct choice identifies the specific structures that are critical for a complete maxillary impression, which includes both the hard palate and the tuberosities.

The hard palate is the bony structure that forms the roof of the mouth, providing a solid foundation for proper dental impressions. It plays a pivotal role in stabilizing dentures and ensuring that any dental appliance fits snugly against the oral tissues. Tuberosities are the rounded bony prominences at the back of the maxillary arch, which are essential landmarks in denture fabrication and fit. Accurate impressions of these structures ensure that any prosthetic devices will have the support they need for proper function.

In contrast to the other choices, while some mentioned structures are important for specific aspects of oral anatomy, they do not encompass the critical landmarks necessary for a maxillary impression. For instance, including soft tissue or areas not pertinent to the fit of prosthetics is not ideal for creating accurate impressions. Thus, recognizing both the hard palate and tuberosities is key in the context of dental impressions, making this the most appropriate selection.