ABSTRACT
The maxillary sinus is the most inferior of the paranasal sinus system: it is a system of intrabony cavities whose ostea all converge on the lateral wall of the nose. Pyramidal in shape with a volume of about 15-30 ml, the maxillary sinus osteum opens into the middle meatus. Blood supply is derived from facial, maxillary, infra-orbital and greater palatine arteries, and lymphatic drainage is to submandibular and deep cervical nodes. Intra-uterine development commences at 3 months of gestation as an outpouch of the middle meatus. At birth it is tubular and reaches 60% of adult size by 9 years; by 12 years its floor parallels that of the nose and it achieves full adult dimensions by about 18 years of age.
