What does extensive opacification of the right maxillary sinus mean?

Opacification: On a radiograph means that something that is normally lucent (dark on x-ray because it lacks density) has some level of radio-opaqueness. This opacification can be due to fluid & mucus from sinusitis, blood from surgery or injury, bone grafting from sinus lifts, to cysts & other masses - benign and malignant. That finding needs to be correlated with any current or recent symptoms, illnesses, etc.

Increased radiopacit: It means that there is something in the sinus that is resisting penetration by x-rays -- could be infection, tumor, thickening of the mucosa, etc.