34 Theories and techniques of oral implantology

Fig. 2-14. The maxillary sinus of a 3-year-old child is quite small.

Fig. 2-15. As the child ages the sinus expands gradually until its floor reaches the same level as the floor of the nose.

brane of the nose, is slow because there is little room for enlargement of the sinus until the teeth erupt and the alveolar process matures. Thus, at the age of 1 year, the sinus is a small triangle still medial to the infraorbital foramen, hugging the wall of the nasal fossa. It gradually enlarges (Fig. 2-14). By the sixth year, it has reached the level of the middle meatus. Between the ages of 8 and 12, the mature teeth erupt

and the sinus expands gradually until its floor reaches the same level as the floor of the nose. By the fifteenth to eighteenth year, the sinus rapidly assumes its full size, at which time the sinus floor is at the level of the alveolus (Fig. 2-15).

As in the mandible, the amount of alveolar bone in the adult determines the location of the floor of the sinus. In a young adult possessing all his teeth,