No matter how careful the operator, taking an impression of the exposed area for fabricating the implant may produce gagging and dizziness. These sensations are not unique to implant procedures. They are also familiar to the prosthodontist as he shapes impression material around the same area for making a conventional appliance. The material interferes with the normal swallowing and equilibrating activities of the site. The unpleasant sensations are fleeting, and can be minimized by making the patient as comfortable as possible.

The Maxillary Sinus

Within each maxilla is a pneumatic sinus, the antrum of Highmore (1), that communicates with the nasal cavity and the other paranasal sinuses : the frontal (2), the ethmoid (3), and the sphenoid (4). The paranasal sinuses are paired and bilateral, but rarely are they symmetrical. In the newborn child they are very small. The maxillary sinus, the largest, is barely the size of a small pea. As the child grows, the sinuses enlarge until they occupy a significant portion of the bones which house them. By the time physical maturity is reached, the maxillary sinus is about 34 mm anterior-posteriorly, 33 mm superior-inferiorly, and 23 mm later-ally, with an average fluid capacity of 15 ml. It is the largest of the paranasal sinuses.